Fix TLS read buffer in ws client: buffer excess SSL_read bytes to prevent loss of multiple WebSocket frames in a single TLS record

The 50ms receive timeout was too short for relays that need time to
process a REQ query before responding. The pool's query_sync already
uses 1000ms. This matches that behavior to avoid premature timeouts.

.clinerules/workspace_rules.md

@@ -1,6 +1,6 @@
 This library is fully staticly linked. There should be no external dependencies.
 
-When building, use build.sh, not make. 
+When building, use build.sh, not make. When building for tests use build.sh -t
 
 When making TUI menus, try to use the first leter of the command and the key to press to execute that command. For example, if the command is "Open file" try to use a keypress of "o" upper or lower case to signal to open the file. Use this instead of number keyed menus when possible. In the command, the letter should be underlined that signifies the command.
 

.gitignore

@@ -7,8 +7,8 @@ nips/
 node_modules/
 nostr-tools/
 tiny-AES-c/
-
-
+blossom/
+ndk/
 
 Trash/debug_tests/
 node_modules/
@@ -19,3 +19,24 @@ node_modules/
 *.dylib
 *.dll
 build/
+
+# Build outputs/binaries (do not track)
+/websocket_debug
+/libnostr_core_arm64.a
+/tests/websocket_debug
+/tests/*_test
+/examples/input_detection
+/examples/keypair_generation
+/examples/mnemonic_derivation
+/examples/mnemonic_generation
+/examples/ots_tool
+/examples/relay_pool
+/examples/send_nip17_dm
+/examples/simple_keygen
+/examples/timestamping
+/examples/utility_functions
+/examples/version_test
+
+# Local OpenTimestamps CLI output
+/examples/timestamped_*
+/examples/*.ots

.roo/commands/push.md

@@ -0,0 +1,7 @@
+---
+description: "Increments and pushes the repo"
+---
+
+Run increment_and_push.sh followed in the command line with a good description of the changes that were made.
+
+For example: ./increment_and_push.sh "Fixed that nasty bug"

AUTOMATIC_VERSIONING.md

@@ -1,223 +0,0 @@
-# NOSTR Core Library - Automatic Versioning System
-
-## Overview
-
-The NOSTR Core Library now features an automatic version increment system that automatically increments the patch version (e.g., v0.2.0 → v0.2.1) with each build. This ensures consistent versioning and traceability across builds.
-
-## How It Works
-
-### Version Format
-The library uses semantic versioning with the format: `vMAJOR.MINOR.PATCH`
-
-- **MAJOR**: Incremented for breaking changes (manual)
-- **MINOR**: Incremented for new features (manual)  
-- **PATCH**: Incremented automatically with each build
-
-### Automatic Increment Process
-
-1. **Version Detection**: The build system scans all git tags matching `v*.*.*` pattern
-2. **Highest Version**: Uses `sort -V` to find the numerically highest version (not chronologically latest)
-3. **Patch Increment**: Increments the patch number by 1
-4. **Git Tag Creation**: Creates a new git tag for the incremented version
-5. **File Generation**: Generates `nostr_core/version.h` and `nostr_core/version.c` with build metadata
-
-### Generated Files
-
-The system automatically generates two files during each build:
-
-#### `nostr_core/version.h`
-```c
-#define VERSION_MAJOR 0
-#define VERSION_MINOR 2  
-#define VERSION_PATCH 1
-#define VERSION_STRING "0.2.1"
-#define VERSION_TAG "v0.2.1"
-
-#define BUILD_DATE "2025-08-09"
-#define BUILD_TIME "10:42:45"
-#define BUILD_TIMESTAMP "2025-08-09 10:42:45"
-
-#define GIT_HASH "ca6b475"
-#define GIT_BRANCH "master"
-
-// API functions
-const char* nostr_core_get_version(void);
-const char* nostr_core_get_version_full(void);
-const char* nostr_core_get_build_info(void);
-```
-
-#### `nostr_core/version.c`
-Contains the implementation of the version API functions.
-
-## Usage
-
-### Building with Auto-Versioning
-
-All major build targets automatically increment the version:
-
-```bash
-# Build static library (increments version)
-./build.sh lib
-
-# Build shared library (increments version)
-./build.sh shared
-
-# Build all libraries (increments version)
-./build.sh all
-
-# Build examples (increments version)
-./build.sh examples
-
-# Install to system (increments version)
-./build.sh install
-```
-
-### Non-Versioned Builds
-
-Some targets do not increment versions:
-
-```bash
-# Clean build artifacts (no version increment)
-./build.sh clean
-
-# Run tests (no version increment)
-./build.sh test
-```
-
-### Using Version Information in Code
-
-```c
-#include "version.h"
-
-// Get version string
-printf("Version: %s\n", nostr_core_get_version());
-
-// Get full version with timestamp and commit
-printf("Full: %s\n", nostr_core_get_version_full());
-
-// Get detailed build information  
-printf("Build: %s\n", nostr_core_get_build_info());
-
-// Use version macros
-#if VERSION_MAJOR >= 1
-    // Use new API
-#else
-    // Use legacy API
-#endif
-```
-
-### Testing Version System
-
-A version test example is provided:
-
-```bash
-# Build and run version test
-gcc -I. -Inostr_core examples/version_test.c -o examples/version_test ./libnostr_core.a ./secp256k1/.libs/libsecp256k1.a -lm
-./examples/version_test
-```
-
-## Version History Tracking
-
-### View All Versions
-```bash
-# List all version tags
-git tag --list
-
-# View version history
-git log --oneline --decorate --graph
-```
-
-### Current Version
-```bash
-# Check current version
-cat VERSION
-
-# Or check the latest git tag
-git describe --tags --abbrev=0
-```
-
-## Manual Version Management
-
-### Major/Minor Version Bumps
-
-For major or minor version changes, manually create the appropriate tag:
-
-```bash
-# For a minor version bump (new features)
-git tag v0.3.0
-
-# For a major version bump (breaking changes)  
-git tag v1.0.0
-```
-
-The next build will automatically increment from the new base version.
-
-### Resetting Version
-
-To reset or fix version numbering:
-
-```bash
-# Delete incorrect tags (if needed)
-git tag -d v0.2.1
-git push origin --delete v0.2.1
-
-# Create correct base version
-git tag v0.2.0
-
-# Next build will create v0.2.1
-```
-
-## Integration Notes
-
-### Makefile Integration
-- The `version.c` file is automatically included in `LIB_SOURCES`
-- Version files are compiled and linked with the library
-- Clean targets remove generated version object files
-
-### Git Integration
-- Version files (`version.h`, `version.c`) are excluded from git via `.gitignore`
-- Only version tags and the `VERSION` file are tracked
-- Build system works in any git repository with version tags
-
-### Build System Integration
-- Version increment is integrated directly into `build.sh`
-- No separate scripts or external dependencies required
-- Self-contained and portable across systems
-
-## Example Output
-
-When building, you'll see output like:
-
-```
-[INFO] Incrementing version...
-[INFO] Current version: v0.2.0
-[INFO] New version: v0.2.1
-[SUCCESS] Created new version tag: v0.2.1
-[SUCCESS] Generated version.h and version.c
-[SUCCESS] Updated VERSION file to 0.2.1
-```
-
-## Troubleshooting
-
-### Version Not Incrementing
-- Ensure you're in a git repository
-- Check that git tags exist with `git tag --list`
-- Verify tag format matches `v*.*.*` pattern
-
-### Tag Already Exists
-If a tag already exists, the build will continue with the existing version:
-
-```
-[WARNING] Tag v0.2.1 already exists - using existing version
-```
-
-### Missing Git Information
-If git is not available, version files will show "unknown" for git hash and branch.
-
-## Benefits
-
-1. **Automatic Traceability**: Every build has a unique version
-2. **Build Metadata**: Includes timestamp, git commit, and branch information  
-3. **API Integration**: Version information accessible via C API
-4. **Zero Maintenance**: No manual version file editing required
-5. **Git Integration**: Automatic git tag creation for version history

CMakeLists.txt

@@ -0,0 +1,119 @@
+cmake_minimum_required(VERSION 3.16)
+
+if(ESP_PLATFORM)
+    idf_component_register(
+        SRCS
+            "nostr_core/nostr_common.c"
+            "nostr_core/nostr_log.c"
+            "nostr_core/nip001.c"
+            "nostr_core/nip004.c"
+            "nostr_core/nip006.c"
+            "nostr_core/nostr_signer.c"
+            "nostr_core/nip019.c"
+            "nostr_core/utils.c"
+            "nostr_core/crypto/nostr_secp256k1.c"
+            "nostr_core/crypto/nostr_aes.c"
+            "nostr_core/crypto/nostr_chacha20.c"
+            "cjson/cJSON.c"
+            "platform/esp32/nostr_platform_esp32.c"
+            "platform/esp32/nostr_http_esp32.c"
+            "platform/esp32/nostr_websocket_esp32.c"
+        INCLUDE_DIRS
+            "."
+            "nostr_core"
+            "nostr_core/crypto"
+            "cjson"
+            "nostr_websocket"
+        REQUIRES
+            secp256k1
+            esp_hw_support
+            esp_http_client
+            esp-tls
+            tcp_transport
+            mbedtls
+    )
+
+    target_compile_definitions(${COMPONENT_LIB} PRIVATE NOSTR_NO_FILESYSTEM=1)
+else()
+    project(nostr_core_lib C)
+
+    add_library(nostr_core STATIC
+        nostr_core/nostr_common.c
+        nostr_core/nostr_log.c
+        nostr_core/request_validator.c
+        nostr_core/nip001.c
+        nostr_core/nip003.c
+        nostr_core/nip004.c
+        nostr_core/nip005.c
+        nostr_core/nip006.c
+        nostr_core/nip011.c
+        nostr_core/nip013.c
+        nostr_core/nip017.c
+        nostr_core/nip019.c
+        nostr_core/nip021.c
+        nostr_core/nip042.c
+        nostr_core/nip044.c
+        nostr_core/nip046.c
+        nostr_core/nip059.c
+        nostr_core/nip060.c
+        nostr_core/nip061.c
+        nostr_core/nostr_signer.c
+        nostr_core/nsigner_transport.c
+        nostr_core/nsigner_client.c
+        nostr_core/utils.c
+        nostr_core/nostr_http.c
+        nostr_core/core_relays.c
+        nostr_core/core_relay_pool.c
+        nostr_core/cashu_mint.c
+        nostr_core/blossom_client.c
+        nostr_core/crypto/nostr_secp256k1.c
+        nostr_core/crypto/nostr_aes.c
+        nostr_core/crypto/nostr_chacha20.c
+        nostr_core/crypto/nostr_poly1305.c
+        nostr_core/crypto/nostr_chacha20poly1305.c
+        cjson/cJSON.c
+        nostr_websocket/nostr_websocket_openssl.c
+        platform/linux.c
+    )
+
+    target_include_directories(nostr_core PUBLIC
+        .
+        nostr_core
+        nostr_core/crypto
+        cjson
+        nostr_websocket
+    )
+    target_compile_definitions(nostr_core PRIVATE NOSTR_ENABLE_NSIGNER_CLIENT=1)
+    target_compile_definitions(nostr_core PRIVATE ENABLE_FILE_LOGGING ENABLE_WEBSOCKET_LOGGING ENABLE_DEBUG_LOGGING)
+
+    # Link system dependencies
+    find_package(PkgConfig QUIET)
+    if(PkgConfig_FOUND)
+        pkg_check_modules(SECP256K1 QUIET libsecp256k1)
+        pkg_check_modules(OPENSSL QUIET openssl)
+        pkg_check_modules(CURL QUIET libcurl)
+    endif()
+
+    if(SECP256K1_FOUND)
+        target_include_directories(nostr_core PRIVATE ${SECP256K1_INCLUDE_DIRS})
+        target_link_libraries(nostr_core PRIVATE ${SECP256K1_LIBRARIES})
+    else()
+        target_link_libraries(nostr_core PRIVATE secp256k1)
+    endif()
+
+    if(OPENSSL_FOUND)
+        target_include_directories(nostr_core PRIVATE ${OPENSSL_INCLUDE_DIRS})
+        target_link_libraries(nostr_core PRIVATE ${OPENSSL_LIBRARIES})
+    else()
+        target_link_libraries(nostr_core PRIVATE ssl crypto)
+    endif()
+
+    if(CURL_FOUND)
+        target_include_directories(nostr_core PRIVATE ${CURL_INCLUDE_DIRS})
+        target_link_libraries(nostr_core PRIVATE ${CURL_LIBRARIES})
+    else()
+        target_link_libraries(nostr_core PRIVATE curl)
+    endif()
+
+    target_link_libraries(nostr_core PRIVATE z dl pthread m)
+endif()

POOL_API.md

@@ -0,0 +1,777 @@
+# Relay Pool API Reference
+
+This document describes the public API for the Nostr Relay Pool implementation in [`core_relay_pool.c`](nostr_core/core_relay_pool.c).
+
+## Function Summary
+
+| Function | Description |
+|----------|-------------|
+| [`nostr_relay_pool_create()`](nostr_core/core_relay_pool.c:594) | Create and initialize a new relay pool |
+| [`nostr_relay_pool_destroy()`](nostr_core/core_relay_pool.c:733) | Destroy pool and cleanup all resources |
+| [`nostr_relay_pool_add_relay()`](nostr_core/core_relay_pool.c:648) | Add a relay URL to the pool |
+| [`nostr_relay_pool_remove_relay()`](nostr_core/core_relay_pool.c:702) | Remove a relay URL from the pool |
+| [`nostr_relay_pool_set_auth()`](nostr_core/core_relay_pool.c:616) | Configure pool-wide NIP-42 authentication key and enable flag |
+| [`nostr_relay_pool_subscribe()`](nostr_core/core_relay_pool.c:778) | Create async subscription with callbacks |
+| [`nostr_pool_subscription_close()`](nostr_core/core_relay_pool.c:491) | Close subscription and free resources |
+| [`nostr_relay_pool_run()`](nostr_core/core_relay_pool.c:1192) | Run event loop for specified timeout |
+| [`nostr_relay_pool_poll()`](nostr_core/core_relay_pool.c:1232) | Single iteration poll and dispatch |
+| [`nostr_relay_pool_query_sync()`](nostr_core/core_relay_pool.c:695) | Synchronous query returning event array |
+| [`nostr_relay_pool_get_event()`](nostr_core/core_relay_pool.c:825) | Get single most recent event |
+| [`nostr_relay_pool_publish_async()`](nostr_core/core_relay_pool.c:866) | Publish event with async callbacks |
+| [`nostr_relay_pool_get_relay_status()`](nostr_core/core_relay_pool.c:944) | Get connection status for a relay |
+| [`nostr_relay_pool_list_relays()`](nostr_core/core_relay_pool.c:960) | List all relays and their statuses |
+| [`nostr_relay_pool_get_relay_stats()`](nostr_core/core_relay_pool.c:992) | Get detailed statistics for a relay |
+| [`nostr_relay_pool_reset_relay_stats()`](nostr_core/core_relay_pool.c:1008) | Reset statistics for a relay |
+| [`nostr_relay_pool_get_relay_query_latency()`](nostr_core/core_relay_pool.c:1045) | Get average query latency for a relay |
+
+## Pool Lifecycle
+
+### Create Pool
+**Function:** [`nostr_relay_pool_create()`](nostr_core/core_relay_pool.c:219)
+```c
+nostr_relay_pool_t* nostr_relay_pool_create(void);
+```
+
+**Example:**
+```c
+#include "nostr_core.h"
+
+int main() {
+    // Create a new relay pool
+    nostr_relay_pool_t* pool = nostr_relay_pool_create();
+    if (!pool) {
+        fprintf(stderr, "Failed to create relay pool\n");
+        return -1;
+    }
+    
+    // Use the pool...
+    
+    // Clean up
+    nostr_relay_pool_destroy(pool);
+    return 0;
+}
+```
+
+### Destroy Pool
+**Function:** [`nostr_relay_pool_destroy()`](nostr_core/core_relay_pool.c:304)
+```c
+void nostr_relay_pool_destroy(nostr_relay_pool_t* pool);
+```
+
+**Example:**
+```c
+// Properly cleanup a relay pool
+void cleanup_pool(nostr_relay_pool_t* pool) {
+    if (pool) {
+        // This will close all active subscriptions and relay connections
+        nostr_relay_pool_destroy(pool);
+        pool = NULL;
+    }
+}
+```
+
+## Relay Management
+
+### Configure Pool Authentication (NIP-42)
+**Function:** [`nostr_relay_pool_set_auth()`](nostr_core/core_relay_pool.c:616)
+```c
+int nostr_relay_pool_set_auth(nostr_relay_pool_t* pool, const unsigned char* private_key, int enable);
+```
+
+**Description:**
+- Sets a pool-wide private key used to sign NIP-42 `AUTH` responses.
+- Enables/disables NIP-42 handling for all relays in the pool.
+- Propagates auth-enabled state to existing relay connections.
+
+**Example:**
+```c
+unsigned char privkey[32];
+nostr_hex_to_bytes("91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe", privkey, 32);
+
+nostr_relay_pool_t* pool = nostr_relay_pool_create(nostr_pool_reconnect_config_default());
+nostr_relay_pool_set_auth(pool, privkey, 1); // enable NIP-42 auto AUTH handling
+```
+
+### Add Relay
+**Function:** [`nostr_relay_pool_add_relay()`](nostr_core/core_relay_pool.c:229)
+```c
+int nostr_relay_pool_add_relay(nostr_relay_pool_t* pool, const char* relay_url);
+```
+
+**Example:**
+```c
+int setup_relays(nostr_relay_pool_t* pool) {
+    const char* relays[] = {
+        "wss://relay.damus.io",
+        "wss://nos.lol",
+        "wss://relay.nostr.band"
+    };
+    
+    for (int i = 0; i < 3; i++) {
+        int result = nostr_relay_pool_add_relay(pool, relays[i]);
+        if (result != NOSTR_SUCCESS) {
+            fprintf(stderr, "Failed to add relay %s: %d\n", relays[i], result);
+            return -1;
+        }
+        printf("Added relay: %s\n", relays[i]);
+    }
+    
+    return 0;
+}
+```
+
+### Remove Relay
+**Function:** [`nostr_relay_pool_remove_relay()`](nostr_core/core_relay_pool.c:273)
+```c
+int nostr_relay_pool_remove_relay(nostr_relay_pool_t* pool, const char* relay_url);
+```
+
+**Example:**
+```c
+int remove_slow_relay(nostr_relay_pool_t* pool) {
+    const char* slow_relay = "wss://slow-relay.example.com";
+    
+    int result = nostr_relay_pool_remove_relay(pool, slow_relay);
+    if (result == NOSTR_SUCCESS) {
+        printf("Successfully removed relay: %s\n", slow_relay);
+    } else {
+        printf("Failed to remove relay %s (may not exist)\n", slow_relay);
+    }
+    
+    return result;
+}
+```
+
+## Subscriptions (Asynchronous)
+
+### Subscribe to Events
+**Function:** [`nostr_relay_pool_subscribe()`](nostr_core/core_relay_pool.c:399)
+```c
+nostr_pool_subscription_t* nostr_relay_pool_subscribe(
+    nostr_relay_pool_t* pool,
+    const char** relay_urls, 
+    int relay_count,
+    cJSON* filter,
+    void (*on_event)(cJSON* event, const char* relay_url, void* user_data),
+    void (*on_eose)(void* user_data),
+    void* user_data);
+```
+
+**Example:**
+```c
+#include "cjson/cJSON.h"
+
+// Event callback - called for each received event
+void handle_event(cJSON* event, const char* relay_url, void* user_data) {
+    cJSON* content = cJSON_GetObjectItem(event, "content");
+    cJSON* pubkey = cJSON_GetObjectItem(event, "pubkey");
+    
+    if (content && pubkey) {
+        printf("Event from %s: %s (by %s)\n", 
+               relay_url, 
+               cJSON_GetStringValue(content),
+               cJSON_GetStringValue(pubkey));
+    }
+}
+
+// EOSE callback - called when all relays finish sending stored events
+void handle_eose(void* user_data) {
+    printf("All relays finished sending stored events\n");
+}
+
+int subscribe_to_notes(nostr_relay_pool_t* pool) {
+    // Create filter for kind 1 (text notes) from last hour
+    cJSON* filter = cJSON_CreateObject();
+    cJSON* kinds = cJSON_CreateArray();
+    cJSON_AddItemToArray(kinds, cJSON_CreateNumber(1));
+    cJSON_AddItemToObject(filter, "kinds", kinds);
+    
+    time_t since = time(NULL) - 3600; // Last hour
+    cJSON_AddItemToObject(filter, "since", cJSON_CreateNumber(since));
+    cJSON_AddItemToObject(filter, "limit", cJSON_CreateNumber(50));
+    
+    // Subscribe to specific relays
+    const char* relay_urls[] = {
+        "wss://relay.damus.io",
+        "wss://nos.lol"
+    };
+    
+    nostr_pool_subscription_t* sub = nostr_relay_pool_subscribe(
+        pool,
+        relay_urls,
+        2,
+        filter,
+        handle_event,
+        handle_eose,
+        NULL  // user_data
+    );
+    
+    cJSON_Delete(filter); // Pool makes its own copy
+    
+    if (!sub) {
+        fprintf(stderr, "Failed to create subscription\n");
+        return -1;
+    }
+    
+    // Drive the event loop to receive events
+    printf("Listening for events for 30 seconds...\n");
+    nostr_relay_pool_run(pool, 30000); // 30 seconds
+    
+    // Close subscription
+    nostr_pool_subscription_close(sub);
+    return 0;
+}
+```
+
+### Close Subscription
+**Function:** [`nostr_pool_subscription_close()`](nostr_core/core_relay_pool.c:491)
+```c
+int nostr_pool_subscription_close(nostr_pool_subscription_t* subscription);
+```
+
+**Example:**
+```c
+// Subscription management with cleanup
+typedef struct {
+    nostr_pool_subscription_t* subscription;
+    int event_count;
+    int should_stop;
+} subscription_context_t;
+
+void event_counter(cJSON* event, const char* relay_url, void* user_data) {
+    subscription_context_t* ctx = (subscription_context_t*)user_data;
+    ctx->event_count++;
+    
+    printf("Received event #%d from %s\n", ctx->event_count, relay_url);
+    
+    // Stop after 10 events
+    if (ctx->event_count >= 10) {
+        ctx->should_stop = 1;
+    }
+}
+
+int limited_subscription(nostr_relay_pool_t* pool) {
+    subscription_context_t ctx = {0};
+    
+    // Create filter
+    cJSON* filter = cJSON_CreateObject();
+    cJSON* kinds = cJSON_CreateArray();
+    cJSON_AddItemToArray(kinds, cJSON_CreateNumber(1));
+    cJSON_AddItemToObject(filter, "kinds", kinds);
+    
+    const char* relay_urls[] = {"wss://relay.damus.io"};
+    
+    ctx.subscription = nostr_relay_pool_subscribe(
+        pool, relay_urls, 1, filter, event_counter, NULL, &ctx);
+    
+    cJSON_Delete(filter);
+    
+    if (!ctx.subscription) {
+        return -1;
+    }
+    
+    // Poll until we should stop
+    while (!ctx.should_stop) {
+        int events = nostr_relay_pool_poll(pool, 100);
+        if (events < 0) break;
+    }
+    
+    // Clean up
+    int result = nostr_pool_subscription_close(ctx.subscription);
+    printf("Subscription closed with result: %d\n", result);
+    
+    return 0;
+}
+```
+
+## Event Loop
+
+### Run Timed Loop
+**Function:** [`nostr_relay_pool_run()`](nostr_core/core_relay_pool.c:1192)
+```c
+int nostr_relay_pool_run(nostr_relay_pool_t* pool, int timeout_ms);
+```
+
+**Example:**
+```c
+int run_event_loop(nostr_relay_pool_t* pool) {
+    printf("Starting event loop for 60 seconds...\n");
+    
+    // Run for 60 seconds, processing all incoming events
+    int total_events = nostr_relay_pool_run(pool, 60000);
+    
+    if (total_events < 0) {
+        fprintf(stderr, "Event loop error\n");
+        return -1;
+    }
+    
+    printf("Processed %d events total\n", total_events);
+    return 0;
+}
+```
+
+### Single Poll Iteration
+**Function:** [`nostr_relay_pool_poll()`](nostr_core/core_relay_pool.c:1232)
+```c
+int nostr_relay_pool_poll(nostr_relay_pool_t* pool, int timeout_ms);
+```
+
+**Example:**
+```c
+// Integration with custom main loop
+int custom_main_loop(nostr_relay_pool_t* pool) {
+    int running = 1;
+    int total_events = 0;
+    
+    while (running) {
+        // Poll for Nostr events (non-blocking with 50ms timeout)
+        int events = nostr_relay_pool_poll(pool, 50);
+        if (events > 0) {
+            total_events += events;
+            printf("Processed %d events this iteration\n", events);
+        }
+        
+        // Do other work in your application
+        // handle_ui_events();
+        // process_background_tasks();
+        
+        // Check exit condition
+        // running = !should_exit();
+        
+        // Simple exit after 100 events for demo
+        if (total_events >= 100) {
+            running = 0;
+        }
+    }
+    
+    printf("Main loop finished, processed %d total events\n", total_events);
+    return 0;
+}
+```
+
+## Synchronous Operations
+
+### Query Multiple Events
+**Function:** [`nostr_relay_pool_query_sync()`](nostr_core/core_relay_pool.c:695)
+```c
+cJSON** nostr_relay_pool_query_sync(
+    nostr_relay_pool_t* pool,
+    const char** relay_urls,
+    int relay_count, 
+    cJSON* filter,
+    int* event_count,
+    int timeout_ms);
+```
+
+**Example:**
+```c
+int query_recent_notes(nostr_relay_pool_t* pool) {
+    // Create filter for recent text notes
+    cJSON* filter = cJSON_CreateObject();
+    cJSON* kinds = cJSON_CreateArray();
+    cJSON_AddItemToArray(kinds, cJSON_CreateNumber(1));
+    cJSON_AddItemToObject(filter, "kinds", kinds);
+    cJSON_AddItemToObject(filter, "limit", cJSON_CreateNumber(20));
+    
+    const char* relay_urls[] = {
+        "wss://relay.damus.io",
+        "wss://nos.lol"
+    };
+    
+    int event_count = 0;
+    cJSON** events = nostr_relay_pool_query_sync(
+        pool, relay_urls, 2, filter, &event_count, 10000); // 10 second timeout
+    
+    cJSON_Delete(filter);
+    
+    if (!events) {
+        printf("No events received or query failed\n");
+        return -1;
+    }
+    
+    printf("Received %d events:\n", event_count);
+    for (int i = 0; i < event_count; i++) {
+        cJSON* content = cJSON_GetObjectItem(events[i], "content");
+        if (content) {
+            printf("  %d: %s\n", i + 1, cJSON_GetStringValue(content));
+        }
+        
+        // Free each event
+        cJSON_Delete(events[i]);
+    }
+    
+    // Free the events array
+    free(events);
+    return event_count;
+}
+```
+
+### Get Single Most Recent Event
+**Function:** [`nostr_relay_pool_get_event()`](nostr_core/core_relay_pool.c:825)
+```c
+cJSON* nostr_relay_pool_get_event(
+    nostr_relay_pool_t* pool,
+    const char** relay_urls,
+    int relay_count,
+    cJSON* filter,
+    int timeout_ms);
+```
+
+**Example:**
+```c
+int get_latest_note_from_pubkey(nostr_relay_pool_t* pool, const char* pubkey_hex) {
+    // Create filter for specific author's notes
+    cJSON* filter = cJSON_CreateObject();
+    cJSON* kinds = cJSON_CreateArray();
+    cJSON_AddItemToArray(kinds, cJSON_CreateNumber(1));
+    cJSON_AddItemToObject(filter, "kinds", kinds);
+    
+    cJSON* authors = cJSON_CreateArray();
+    cJSON_AddItemToArray(authors, cJSON_CreateString(pubkey_hex));
+    cJSON_AddItemToObject(filter, "authors", authors);
+    
+    cJSON_AddItemToObject(filter, "limit", cJSON_CreateNumber(1));
+    
+    const char* relay_urls[] = {"wss://relay.damus.io"};
+    
+    cJSON* event = nostr_relay_pool_get_event(
+        pool, relay_urls, 1, filter, 5000); // 5 second timeout
+    
+    cJSON_Delete(filter);
+    
+    if (!event) {
+        printf("No recent event found for pubkey %s\n", pubkey_hex);
+        return -1;
+    }
+    
+    cJSON* content = cJSON_GetObjectItem(event, "content");
+    cJSON* created_at = cJSON_GetObjectItem(event, "created_at");
+    
+    if (content && created_at) {
+        printf("Latest note: %s (created at %ld)\n", 
+               cJSON_GetStringValue(content),
+               (long)cJSON_GetNumberValue(created_at));
+    }
+    
+    cJSON_Delete(event);
+    return 0;
+}
+```
+
+### Publish Event
+**Function:** [`nostr_relay_pool_publish_async()`](nostr_core/core_relay_pool.c:866)
+```c
+int nostr_relay_pool_publish_async(
+    nostr_relay_pool_t* pool,
+    const char** relay_urls,
+    int relay_count,
+    cJSON* event);
+```
+
+**Example:**
+```c
+int publish_text_note(nostr_relay_pool_t* pool, const char* content) {
+    // Create a basic text note event (this is simplified - real implementation
+    // would need proper signing with private key)
+    cJSON* event = cJSON_CreateObject();
+    cJSON_AddItemToObject(event, "kind", cJSON_CreateNumber(1));
+    cJSON_AddItemToObject(event, "content", cJSON_CreateString(content));
+    cJSON_AddItemToObject(event, "created_at", cJSON_CreateNumber(time(NULL)));
+    
+    // In real usage, you'd add pubkey, id, sig fields here
+    cJSON_AddItemToObject(event, "pubkey", cJSON_CreateString("your_pubkey_hex"));
+    cJSON_AddItemToObject(event, "id", cJSON_CreateString("event_id_hash"));
+    cJSON_AddItemToObject(event, "sig", cJSON_CreateString("event_signature"));
+    cJSON_AddItemToObject(event, "tags", cJSON_CreateArray());
+    
+    const char* relay_urls[] = {
+        "wss://relay.damus.io",
+        "wss://nos.lol",
+        "wss://relay.nostr.band"
+    };
+    
+    printf("Publishing note: %s\n", content);
+    
+    int success_count = nostr_relay_pool_publish_async(
+        pool, relay_urls, 3, event, my_callback, user_data);
+    
+    cJSON_Delete(event);
+    
+    printf("Successfully published to %d out of 3 relays\n", success_count);
+    
+    if (success_count == 0) {
+        fprintf(stderr, "Failed to publish to any relay\n");
+        return -1;
+    }
+    
+    return success_count;
+}
+```
+
+## Status and Statistics
+
+### Get Relay Status
+**Function:** [`nostr_relay_pool_get_relay_status()`](nostr_core/core_relay_pool.c:944)
+```c
+nostr_pool_relay_status_t nostr_relay_pool_get_relay_status(
+    nostr_relay_pool_t* pool, 
+    const char* relay_url);
+```
+
+**Example:**
+```c
+void check_relay_status(nostr_relay_pool_t* pool, const char* relay_url) {
+    nostr_pool_relay_status_t status = nostr_relay_pool_get_relay_status(pool, relay_url);
+    
+    const char* status_str;
+    switch (status) {
+        case NOSTR_POOL_RELAY_DISCONNECTED:
+            status_str = "DISCONNECTED";
+            break;
+        case NOSTR_POOL_RELAY_CONNECTING:
+            status_str = "CONNECTING";
+            break;
+        case NOSTR_POOL_RELAY_CONNECTED:
+            status_str = "CONNECTED";
+            break;
+        case NOSTR_POOL_RELAY_ERROR:
+            status_str = "ERROR";
+            break;
+        default:
+            status_str = "UNKNOWN";
+            break;
+    }
+    
+    printf("Relay %s status: %s\n", relay_url, status_str);
+}
+```
+
+### List All Relays
+**Function:** [`nostr_relay_pool_list_relays()`](nostr_core/core_relay_pool.c:960)
+```c
+int nostr_relay_pool_list_relays(
+    nostr_relay_pool_t* pool,
+    char*** relay_urls,
+    nostr_pool_relay_status_t** statuses);
+```
+
+**Example:**
+```c
+void print_all_relays(nostr_relay_pool_t* pool) {
+    char** relay_urls = NULL;
+    nostr_pool_relay_status_t* statuses = NULL;
+    
+    int count = nostr_relay_pool_list_relays(pool, &relay_urls, &statuses);
+    
+    if (count < 0) {
+        printf("Failed to list relays\n");
+        return;
+    }
+    
+    if (count == 0) {
+        printf("No relays configured\n");
+        return;
+    }
+    
+    printf("Configured relays (%d):\n", count);
+    for (int i = 0; i < count; i++) {
+        const char* status_str = (statuses[i] == NOSTR_POOL_RELAY_CONNECTED) ? 
+                                 "CONNECTED" : "DISCONNECTED";
+        printf("  %s - %s\n", relay_urls[i], status_str);
+        
+        // Free the duplicated URL string
+        free(relay_urls[i]);
+    }
+    
+    // Free the arrays
+    free(relay_urls);
+    free(statuses);
+}
+```
+
+### Get Relay Statistics
+**Function:** [`nostr_relay_pool_get_relay_stats()`](nostr_core/core_relay_pool.c:992)
+```c
+const nostr_relay_stats_t* nostr_relay_pool_get_relay_stats(
+    nostr_relay_pool_t* pool, 
+    const char* relay_url);
+```
+
+**Example:**
+```c
+void print_relay_stats(nostr_relay_pool_t* pool, const char* relay_url) {
+    const nostr_relay_stats_t* stats = nostr_relay_pool_get_relay_stats(pool, relay_url);
+    
+    if (!stats) {
+        printf("No stats available for relay %s\n", relay_url);
+        return;
+    }
+    
+    printf("Statistics for %s:\n", relay_url);
+    printf("  Connection attempts: %d\n", stats->connection_attempts);
+    printf("  Connection failures: %d\n", stats->connection_failures);
+    printf("  Events received: %d\n", stats->events_received);
+    printf("  Events published: %d\n", stats->events_published);
+    printf("  Events published OK: %d\n", stats->events_published_ok);
+    printf("  Events published failed: %d\n", stats->events_published_failed);
+    printf("  Query latency avg: %.2f ms\n", stats->query_latency_avg);
+    printf("  Query samples: %d\n", stats->query_samples);
+    printf("  Publish latency avg: %.2f ms\n", stats->publish_latency_avg);
+    printf("  Publish samples: %d\n", stats->publish_samples);
+    
+    if (stats->last_event_time > 0) {
+        printf("  Last event: %ld seconds ago\n", 
+               time(NULL) - stats->last_event_time);
+    }
+}
+```
+
+### Reset Relay Statistics
+**Function:** [`nostr_relay_pool_reset_relay_stats()`](nostr_core/core_relay_pool.c:1008)
+```c
+int nostr_relay_pool_reset_relay_stats(
+    nostr_relay_pool_t* pool, 
+    const char* relay_url);
+```
+
+**Example:**
+```c
+void reset_stats_for_relay(nostr_relay_pool_t* pool, const char* relay_url) {
+    int result = nostr_relay_pool_reset_relay_stats(pool, relay_url);
+    
+    if (result == NOSTR_SUCCESS) {
+        printf("Successfully reset statistics for %s\n", relay_url);
+    } else {
+        printf("Failed to reset statistics for %s\n", relay_url);
+    }
+}
+```
+
+### Get Query Latency
+**Function:** [`nostr_relay_pool_get_relay_query_latency()`](nostr_core/core_relay_pool.c:1045)
+```c
+double nostr_relay_pool_get_relay_query_latency(
+    nostr_relay_pool_t* pool, 
+    const char* relay_url);
+```
+
+**Example:**
+```c
+void check_relay_performance(nostr_relay_pool_t* pool) {
+    const char* relays[] = {
+        "wss://relay.damus.io",
+        "wss://nos.lol",
+        "wss://relay.nostr.band"
+    };
+    
+    printf("Relay performance comparison:\n");
+    for (int i = 0; i < 3; i++) {
+        double latency = nostr_relay_pool_get_relay_query_latency(pool, relays[i]);
+        
+        if (latency >= 0) {
+            printf("  %s: %.2f ms average query latency\n", relays[i], latency);
+        } else {
+            printf("  %s: No latency data available\n", relays[i]);
+        }
+    }
+}
+```
+
+## Complete Example Application
+
+```c
+#include "nostr_core.h"
+#include "cjson/cJSON.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+// Global context for the example
+typedef struct {
+    int event_count;
+    int max_events;
+} app_context_t;
+
+void on_text_note(cJSON* event, const char* relay_url, void* user_data) {
+    app_context_t* ctx = (app_context_t*)user_data;
+    
+    cJSON* content = cJSON_GetObjectItem(event, "content");
+    if (content && cJSON_IsString(content)) {
+        printf("[%s] Note #%d: %s\n", 
+               relay_url, ++ctx->event_count, cJSON_GetStringValue(content));
+    }
+}
+
+void on_subscription_complete(void* user_data) {
+    printf("All relays finished sending stored events\n");
+}
+
+int main() {
+    // Initialize pool
+    nostr_relay_pool_t* pool = nostr_relay_pool_create();
+    if (!pool) {
+        fprintf(stderr, "Failed to create relay pool\n");
+        return 1;
+    }
+    
+    // Add relays
+    const char* relays[] = {
+        "wss://relay.damus.io",
+        "wss://nos.lol"
+    };
+    
+    for (int i = 0; i < 2; i++) {
+        if (nostr_relay_pool_add_relay(pool, relays[i]) != NOSTR_SUCCESS) {
+            fprintf(stderr, "Failed to add relay: %s\n", relays[i]);
+        }
+    }
+    
+    // Create filter for recent text notes
+    cJSON* filter = cJSON_CreateObject();
+    cJSON* kinds = cJSON_CreateArray();
+    cJSON_AddItemToArray(kinds, cJSON_CreateNumber(1));
+    cJSON_AddItemToObject(filter, "kinds", kinds);
+    cJSON_AddItemToObject(filter, "limit", cJSON_CreateNumber(10));
+    
+    // Set up context
+    app_context_t ctx = {0, 10};
+    
+    // Subscribe
+    nostr_pool_subscription_t* sub = nostr_relay_pool_subscribe(
+        pool, relays, 2, filter, on_text_note, on_subscription_complete, &ctx);
+    
+    cJSON_Delete(filter);
+    
+    if (!sub) {
+        fprintf(stderr, "Failed to create subscription\n");
+        nostr_relay_pool_destroy(pool);
+        return 1;
+    }
+    
+    // Run event loop for 30 seconds
+    printf("Listening for events...\n");
+    nostr_relay_pool_run(pool, 30000);
+    
+    // Print final stats
+    for (int i = 0; i < 2; i++) {
+        print_relay_stats(pool, relays[i]);
+    }
+    
+    // Cleanup
+    nostr_pool_subscription_close(sub);
+    nostr_relay_pool_destroy(pool);
+    
+    printf("Application finished. Received %d events total.\n", ctx.event_count);
+    return 0;
+}
+```
+
+## Notes
+
+- All functions are **not thread-safe**. Use from a single thread or add external synchronization.
+- **Memory ownership**: The pool duplicates filters and URLs internally. Caller owns returned events and must free them.
+- **Event deduplication** is applied pool-wide using a circular buffer of 1000 event IDs.
+- **Ping functionality** is currently disabled in this build.
+- **NIP-42 behavior**: With [`nostr_relay_pool_set_auth()`](nostr_core/core_relay_pool.c:616) enabled, the pool will respond to relay `AUTH` challenges automatically using [`nostr_nip42_create_auth_event()`](nostr_core/nip042.c:26) and [`nostr_nip42_create_auth_message()`](nostr_core/nip042.c:84).
+- **Reconnection** happens on-demand when sending, but active subscriptions are not automatically re-sent after reconnect.
+- **Polling model**: You must drive the event loop via [`nostr_relay_pool_run()`](nostr_core/core_relay_pool.c:1745) or [`nostr_relay_pool_poll()`](nostr_core/core_relay_pool.c:1785) to receive events.

README.md

@@ -1,46 +1,103 @@
 # NOSTR Core Library
 
-A comprehensive, production-ready C library for NOSTR protocol implementation with OpenSSL-based cryptography and extensive protocol support.
+A C library for NOSTR protocol implementation. Work in progress.
 
-[![Version](https://img.shields.io/badge/version-0.1.20-blue.svg)](VERSION)
+[![Version](https://img.shields.io/badge/version-0.6.0-blue.svg)](VERSION)
 [![License](https://img.shields.io/badge/license-MIT-green.svg)](#license)
 [![Build Status](https://img.shields.io/badge/build-passing-brightgreen.svg)](#building)
 
-## 🚀 Features
 
-### Core Protocol Support
-- **NIP-01**: Basic protocol flow - event creation, signing, and validation
-- **NIP-04**: Encrypted direct messages (ECDH + AES-CBC + Base64)
-- **NIP-05**: DNS-based internet identifier verification
-- **NIP-06**: Key derivation from mnemonic (BIP39/BIP32 compliant)  
-- **NIP-11**: Relay information documents
-- **NIP-13**: Proof of Work for events
-- **NIP-44**: Versioned encrypted direct messages (ECDH + ChaCha20 + HMAC)
+## 📋 NIP Implementation Status
 
-### Cryptographic Features
-- **OpenSSL-Based**: Production-grade cryptography with OpenSSL backend
-- **Secp256k1**: Complete elliptic curve implementation bundled
-- **BIP39**: Mnemonic phrase generation and validation
-- **BIP32**: Hierarchical deterministic key derivation
-- **ChaCha20**: Stream cipher for NIP-44 encryption
-- **AES-CBC**: Block cipher for NIP-04 encryption
-- **Schnorr Signatures**: BIP-340 compliant signing and verification
+### Core Protocol NIPs
+- [x] [NIP-01](nips/01.md) - Basic protocol flow - event creation, signing, and validation
+- [ ] [NIP-02](nips/02.md) - Contact List and Petnames
+- [x] [NIP-03](nips/03.md) - OpenTimestamps Attestations for Events
+- [x] [NIP-04](nips/04.md) - Encrypted Direct Messages (legacy)
+- [x] [NIP-05](nips/05.md) - Mapping Nostr keys to DNS-based internet identifiers
+- [x] [NIP-06](nips/06.md) - Basic key derivation from mnemonic seed phrase
+- [-] [NIP-07](nips/07.md) - `window.nostr` capability for web browsers
+- [ ] [NIP-08](nips/08.md) - Handling Mentions
+- [ ] [NIP-09](nips/09.md) - Event Deletion
+- [ ] [NIP-10](nips/10.md) - Conventions for clients' use of `e` and `p` tags in text events
+- [x] [NIP-11](nips/11.md) - Relay Information Document
+- [ ] [NIP-12](nips/12.md) - Generic Tag Queries
+- [x] [NIP-13](nips/13.md) - Proof of Work
+- [ ] [NIP-14](nips/14.md) - Subject tag in text events
+- [ ] [NIP-15](nips/15.md) - Nostr Marketplace (for resilient marketplaces)
+- [ ] [NIP-16](nips/16.md) - Event Treatment
+- [x] [NIP-17](nips/17.md) - Private Direct Messages
+- [ ] [NIP-18](nips/18.md) - Reposts
+- [x] [NIP-19](nips/19.md) - bech32-encoded entities
+- [ ] [NIP-20](nips/20.md) - Command Results
+- [x] [NIP-21](nips/21.md) - `nostr:` URI scheme
+- [ ] [NIP-22](nips/22.md) - Event `created_at` Limits
+- [ ] [NIP-23](nips/23.md) - Long-form Content
+- [ ] [NIP-24](nips/24.md) - Extra metadata fields and tags
+- [ ] [NIP-25](nips/25.md) - Reactions
+- [ ] [NIP-26](nips/26.md) - Delegated Event Signing
+- [ ] [NIP-27](nips/27.md) - Text Note References
+- [ ] [NIP-28](nips/28.md) - Public Chat
+- [ ] [NIP-29](nips/29.md) - Relay-based Groups
+- [ ] [NIP-30](nips/30.md) - Custom Emoji
+- [ ] [NIP-31](nips/31.md) - Dealing with Unknown Events
+- [ ] [NIP-32](nips/32.md) - Labeling
+- [ ] [NIP-33](nips/33.md) - Parameterized Replaceable Events
+- [ ] [NIP-34](nips/34.md) - `git` stuff
+- [ ] [NIP-35](nips/35.md) - Torrents
+- [ ] [NIP-36](nips/36.md) - Sensitive Content / Content Warning
+- [ ] [NIP-37](nips/37.md) - Draft Events
+- [ ] [NIP-38](nips/38.md) - User Statuses
+- [ ] [NIP-39](nips/39.md) - External Identities in Profiles
+- [ ] [NIP-40](nips/40.md) - Expiration Timestamp
+- [x] [NIP-42](nips/42.md) - Authentication of clients to relays
+- [x] [NIP-44](nips/44.md) - Versioned Encryption
+- [ ] [NIP-45](nips/45.md) - Counting results
+- [x] [NIP-46](nips/46.md) - Nostr Remote Signing
+- [ ] [NIP-47](nips/47.md) - Wallet Connect
+- [ ] [NIP-48](nips/48.md) - Proxy Tags
+- [ ] [NIP-49](nips/49.md) - Private Key Encryption
+- [ ] [NIP-50](nips/50.md) - Search Capability
+- [ ] [NIP-51](nips/51.md) - Lists
+- [ ] [NIP-52](nips/52.md) - Calendar Events
+- [ ] [NIP-53](nips/53.md) - Live Activities
+- [ ] [NIP-54](nips/54.md) - Wiki
+- [-] [NIP-55](nips/55.md) - Android Signer Application
+- [ ] [NIP-56](nips/56.md) - Reporting
+- [ ] [NIP-57](nips/57.md) - Lightning Zaps
+- [ ] [NIP-58](nips/58.md) - Badges
+- [x] [NIP-59](nips/59.md) - Gift Wrap
+- [ ] [NIP-60](nips/60.md) - Cashu Wallet
+- [ ] [NIP-61](nips/61.md) - Nutzaps
+- [ ] [NIP-62](nips/62.md) - Log events
+- [-] [NIP-64](nips/64.md) - Chess (PGN)
+- [ ] [NIP-65](nips/65.md) - Relay List Metadata
+- [ ] [NIP-66](nips/66.md) - Relay Monitor
+- [-] [NIP-68](nips/68.md) - Web badges
+- [ ] [NIP-69](nips/69.md) - Peer-to-peer Order events
+- [ ] [NIP-70](nips/70.md) - Protected Events
+- [ ] [NIP-71](nips/71.md) - Video Events
+- [ ] [NIP-72](nips/72.md) - Moderated Communities
+- [ ] [NIP-73](nips/73.md) - External Content IDs
+- [ ] [NIP-75](nips/75.md) - Zap Goals
+- [ ] [NIP-77](nips/77.md) - Arbitrary custom app data
+- [ ] [NIP-78](nips/78.md) - Application-specific data
+- [ ] [NIP-84](nips/84.md) - Highlights
+- [ ] [NIP-86](nips/86.md) - Relay Management API
+- [ ] [NIP-87](nips/87.md) - Relay List Recommendations
+- [-] [NIP-88](nips/88.md) - Stella: A Stellar Relay
+- [ ] [NIP-89](nips/89.md) - Recommended Application Handlers
+- [ ] [NIP-90](nips/90.md) - Data Vending Machines
+- [ ] [NIP-92](nips/92.md) - Media Attachments
+- [ ] [NIP-94](nips/94.md) - File Metadata
+- [ ] [NIP-96](nips/96.md) - HTTP File Storage Integration
+- [ ] [NIP-98](nips/98.md) - HTTP Auth
+- [ ] [NIP-99](nips/99.md) - Classified Listings
 
-### Networking & Relay Support
-- **Multi-Relay Queries**: Synchronous querying with progress callbacks
-- **Relay Pools**: Asynchronous connection management with statistics
-- **OpenSSL WebSocket Communication**: Full relay protocol support with TLS
-- **NIP-05 Identifier Verification**: DNS-based identity resolution
-- **NIP-11 Relay Information**: Automatic relay capability discovery
-- **Event Deduplication**: Automatic handling of duplicate events across relays
-- **Connection Management**: Automatic reconnection and error handling
+**Legend:** ✅ Fully Implemented | ⚠️ Partial Implementation | ❌ Not Implemented | ➖ Not Applicable
+
+**Implementation Summary:** 13 of 96+ NIPs fully implemented (13.5%)
 
-### Developer Experience
-- **System Dependencies**: Uses system-installed OpenSSL, curl, and secp256k1 libraries
-- **Thread-Safe**: Core cryptographic functions are stateless
-- **Cross-Platform**: Builds on Linux, macOS, Windows
-- **Comprehensive Examples**: Ready-to-run demonstration programs
-- **Automatic Versioning**: Git-tag based version management
 
 ## 📦 Quick Start
 
@@ -54,12 +111,12 @@ A comprehensive, production-ready C library for NOSTR protocol implementation wi
 
 2. **Build the library:**
    ```bash
-   ./build.sh lib
+   ./build.sh
    ```
 
-3. **Run examples:**
+3. **Build and run examples:**
    ```bash
-   ./build.sh examples
+   ./build.sh -e
    ./examples/simple_keygen
    ```
 
@@ -104,7 +161,7 @@ int main() {
 
 **Compile and run:**
 ```bash
-gcc example.c -o example ./libnostr_core.a -lm
+gcc example.c -o example ./libnostr_core_x64.a -lz -ldl -lpthread -lm -lssl -lcrypto -lcurl -lsecp256k1
 ./example
 ```
 
@@ -113,27 +170,13 @@ gcc example.c -o example ./libnostr_core.a -lm
 ### Build Targets
 
 ```bash
-./build.sh lib        # Build static library (default)
-./build.sh examples   # Build examples
-./build.sh test       # Run test suite
-./build.sh clean      # Clean build artifacts
-./build.sh install    # Install to system
-```
-
-### Manual Building
-
-```bash
-# Build static library
-make
-
-# Build examples  
-make examples
-
-# Run tests
-make test-crypto
-
-# Clean
-make clean
+./build.sh                    # Build static library (default)
+./build.sh --nips=all         # Force build with all available NIPs
+./build.sh -t                 # Build all test executables in tests/
+./build.sh -e                 # Build all examples in examples/
+./build.sh -t -e              # Build library + tests + examples
+./build.sh --nips=46          # Build specifically with NIP-046 support
+./build.sh --help             # Show all options
 ```
 
 ### Dependencies
@@ -245,20 +288,38 @@ publish_result_t* synchronous_publish_event_with_progress(const char** relay_url
 
 ### Relay Pools (Asynchronous)
 ```c
-// Create and manage relay pool
-nostr_relay_pool_t* nostr_relay_pool_create(void);
+// Create and manage relay pool with reconnection
+nostr_pool_reconnect_config_t* config = nostr_pool_reconnect_config_default();
+nostr_relay_pool_t* nostr_relay_pool_create(nostr_pool_reconnect_config_t* config);
 int nostr_relay_pool_add_relay(nostr_relay_pool_t* pool, const char* relay_url);
+int nostr_relay_pool_set_auth(nostr_relay_pool_t* pool, const unsigned char* private_key, int enable);
 void nostr_relay_pool_destroy(nostr_relay_pool_t* pool);
 
-// Subscribe to events
+// Subscribe to events (with auto-reconnection)
 nostr_pool_subscription_t* nostr_relay_pool_subscribe(
     nostr_relay_pool_t* pool, const char** relay_urls, int relay_count, cJSON* filter,
     void (*on_event)(cJSON* event, const char* relay_url, void* user_data),
-    void (*on_eose)(void* user_data), void* user_data);
+    void (*on_eose)(void* user_data), void* user_data, int close_on_eose);
 
-// Run event loop
+// Enable NIP-42 auth (auto-responds to relay AUTH challenges)
+unsigned char private_key[32];
+nostr_hex_to_bytes("91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe", private_key, 32);
+nostr_relay_pool_set_auth(pool, private_key, 1);
+
+// Run event loop (handles reconnection + incoming AUTH/NOTICE/OK messages)
 int nostr_relay_pool_run(nostr_relay_pool_t* pool, int timeout_ms);
 int nostr_relay_pool_poll(nostr_relay_pool_t* pool, int timeout_ms);
+
+// Reconnection configuration
+typedef struct {
+    int enable_auto_reconnect;        // Enable automatic reconnection
+    int max_reconnect_attempts;       // Maximum retry attempts
+    int initial_reconnect_delay_ms;   // Initial delay between attempts
+    int max_reconnect_delay_ms;       // Maximum delay cap
+    int reconnect_backoff_multiplier; // Exponential backoff factor
+    int ping_interval_seconds;        // Health check ping interval
+    int pong_timeout_seconds;         // Pong response timeout
+} nostr_pool_reconnect_config_t;
 ```
 
 ### NIP-05 Identifier Verification
@@ -285,6 +346,171 @@ int nostr_nip11_fetch_relay_info(const char* relay_url, nostr_relay_info_t** inf
 void nostr_nip11_relay_info_free(nostr_relay_info_t* info);
 ```
 
+## Signer abstraction & nsigner integration
+
+All signing/encryption operations can run through an opaque `nostr_signer_t` handle. This provides:
+
+- **LOCAL backend** (`nostr_signer_local`) using a raw 32-byte private key (output-equivalent to legacy raw-key APIs).
+- **REMOTE backends** (`nostr_signer_nsigner_*`) that call a running `n_signer` process/device over supported transports.
+
+### Core signer verbs (exact signatures)
+
+```c
+/* Lifecycle */
+nostr_signer_t* nostr_signer_local(const unsigned char private_key[32]);
+void nostr_signer_free(nostr_signer_t* signer);
+
+/* Core verbs */
+int nostr_signer_get_public_key(nostr_signer_t* signer, char out_pubkey_hex[65]);
+int nostr_signer_sign_event(nostr_signer_t* signer, const cJSON* unsigned_event, cJSON** signed_event_out);
+
+/* Encryption verbs */
+int nostr_signer_nip04_encrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* plaintext,
+                               char** ciphertext_out);
+int nostr_signer_nip04_decrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* ciphertext,
+                               char** plaintext_out);
+int nostr_signer_nip44_encrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* plaintext,
+                               char** ciphertext_out);
+int nostr_signer_nip44_decrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* ciphertext,
+                               char** plaintext_out);
+```
+
+### Backends / transports
+
+Remote signer factories (available when `NOSTR_ENABLE_NSIGNER_CLIENT` is enabled):
+
+```c
+nostr_signer_t* nostr_signer_nsigner_unix(const char* socket_name, const char* role, int timeout_ms);
+nostr_signer_t* nostr_signer_nsigner_serial(const char* device_path, const char* role, int timeout_ms);
+nostr_signer_t* nostr_signer_nsigner_tcp(const char* host, int port, const char* role, int timeout_ms);
+nostr_signer_t* nostr_signer_nsigner_fds(int read_fd, int write_fd, const char* role, int timeout_ms);
+int nostr_signer_nsigner_set_auth(nostr_signer_t* signer,
+                                  const unsigned char auth_privkey[32],
+                                  const char* label);
+```
+
+Transport layer constructors and discovery helpers:
+
+```c
+nsigner_transport_t* nsigner_transport_open_unix(const char* socket_name, int timeout_ms);
+nsigner_transport_t* nsigner_transport_open_tcp(const char* host, int port, int timeout_ms);
+nsigner_transport_t* nsigner_transport_open_serial(const char* device_path, int timeout_ms);
+nsigner_transport_t* nsigner_transport_open_fds(int read_fd, int write_fd, int timeout_ms);
+int nsigner_transport_list_unix(char names[][64], int max_names);
+int nsigner_transport_list_serial(char paths[][64], int max_paths);
+```
+
+Supported transport modes:
+- UNIX abstract socket (`unix:<name>`, no leading `@` in API input)
+- USB CDC-ACM serial (`serial:/dev/ttyACM0`)
+- TCP (`tcp:<host>:<port>`)
+- Existing framed fd pair (`fds:<read_fd>:<write_fd>`, useful for stdio/qrexec-style bridges)
+
+Build gating:
+- Desktop builds enable `NOSTR_ENABLE_NSIGNER_CLIENT`.
+- ESP32 builds exclude the nsigner client transport/client sources and do not define the flag.
+- n_signer’s own build keeps this client side disabled.
+
+Wire contract (high level):
+- Framing is **4-byte big-endian length + JSON payload**.
+- Payload length must be in `[1, 65536]` bytes.
+- TCP uses a kind-27235 auth envelope (`nsigner_rpc`, `nsigner_method`, `nsigner_body_hash`).
+- See n_signer docs for authoritative protocol details.
+
+### Using a signer in higher-level APIs
+
+Pattern: existing raw-private-key functions remain unchanged; signer-aware siblings are provided as `*_with_signer` variants.
+
+Covered modules and functions:
+
+- NIP-01 (`nostr_core/nip001.h`)
+  - `cJSON* nostr_create_and_sign_event_with_signer(int kind, const char* content, cJSON* tags, nostr_signer_t* signer, time_t timestamp);`
+
+- NIP-03 OpenTimestamps (`nostr_core/nip003.h`)
+  - `cJSON* nostr_nip03_create_proof_event_with_signer(const char* target_event_id, int target_event_kind, const char* ots_data_base64, const char* relay_url, nostr_signer_t* signer);`
+  - `char* nostr_nip03_request_timestamp(const char* event_id_hex, const char* calendar_url, int timeout_seconds);`
+  - `int nostr_nip03_is_proof_complete(const char* ots_data_base64);`
+  - `int nostr_nip03_get_attestation_info(const char* ots_data_base64, int* has_bitcoin, int* has_litecoin, int* has_pending, uint64_t* bitcoin_height, uint64_t* litecoin_height, char** pending_uri_out);`
+  - `char* nostr_nip03_upgrade_proof(const char* ots_data_base64, const char* calendar_url, int timeout_seconds);`
+  - `int nostr_nip03_verify_proof(const char* ots_data_base64, const char* target_digest_hex, uint64_t* block_height_out, time_t* block_time_out);`
+
+- NIP-17 (`nostr_core/nip017.h`)
+  - `cJSON* nostr_nip17_create_relay_list_event_with_signer(const char** relay_urls, int num_relays, nostr_signer_t* signer);`
+  - `int nostr_nip17_send_dm_with_signer(cJSON* dm_event, const char** recipient_pubkeys, int num_recipients, nostr_signer_t* signer, cJSON** gift_wraps_out, int max_gift_wraps, long max_delay_sec);`
+  - `cJSON* nostr_nip17_receive_dm_with_signer(cJSON* gift_wrap, nostr_signer_t* signer);`
+
+- NIP-42 (`nostr_core/nip042.h`)
+  - `cJSON* nostr_nip42_create_auth_event_with_signer(const char* challenge, const char* relay_url, nostr_signer_t* signer, time_t timestamp);`
+
+- NIP-46 client/event helpers (`nostr_core/nip046.h`)
+  - `cJSON* nostr_nip46_create_request_event_with_signer(const nostr_nip46_request_t* request, nostr_signer_t* signer, const unsigned char* recipient_public_key, time_t timestamp);`
+  - `cJSON* nostr_nip46_create_response_event_with_signer(const nostr_nip46_response_t* response, nostr_signer_t* signer, const unsigned char* recipient_public_key, time_t timestamp);`
+  - `int nostr_nip46_decrypt_event_with_signer(cJSON* event, nostr_signer_t* signer, char** output_out);`
+  - `int nostr_nip46_client_session_init_with_signer(nostr_nip46_client_session_t* session, nostr_signer_t* signer, const char* bunker_url);`
+
+- NIP-60 (`nostr_core/nip060.h`)
+  - `cJSON* nostr_nip60_create_wallet_event_with_signer(const nostr_nip60_wallet_data_t* wallet_data, nostr_signer_t* signer, time_t timestamp);`
+  - `cJSON* nostr_nip60_create_token_event_with_signer(const nostr_nip60_token_data_t* token_data, nostr_signer_t* signer, time_t timestamp);`
+  - `cJSON* nostr_nip60_create_token_deletion_with_signer(const char* token_event_id, nostr_signer_t* signer, time_t timestamp);`
+  - `cJSON* nostr_nip60_create_rollover_token_with_signer(const nostr_nip60_token_data_t* remaining_proofs, const char** deleted_event_ids, int deleted_count, nostr_signer_t* signer, time_t timestamp);`
+  - `cJSON* nostr_nip60_create_history_event_with_signer(const nostr_nip60_history_data_t* history_data, nostr_signer_t* signer, time_t timestamp);`
+  - `cJSON* nostr_nip60_create_quote_event_with_signer(const char* quote_id, const char* mint_url, time_t expiration, nostr_signer_t* signer, time_t timestamp);`
+
+- NIP-61 (`nostr_core/nip061.h`)
+  - `cJSON* nostr_nip61_create_nutzap_info_event_with_signer(const nostr_nip61_nutzap_info_t* info, nostr_signer_t* signer, time_t timestamp);`
+  - `cJSON* nostr_nip61_create_nutzap_event_with_signer(const nostr_nip61_nutzap_data_t* nutzap_data, nostr_signer_t* signer, time_t timestamp);`
+  - `cJSON* nostr_nip61_create_redemption_event_with_signer(const char* nutzap_event_id, const char* nutzap_relay_hint, const char* sender_pubkey, const char* created_token_event_id, const char* created_token_relay_hint, uint64_t amount, nostr_signer_t* signer, time_t timestamp);`
+
+- Blossom auth/upload/delete (`nostr_core/blossom_client.h`)
+  - `char* blossom_create_auth_header_with_signer(nostr_signer_t* signer, const char* operation, const char* sha256_hex, int expiration_seconds, time_t timestamp);`
+  - `int blossom_upload_with_signer(const char* server_url, const unsigned char* data, size_t data_len, const char* content_type, nostr_signer_t* signer, const char* sha256_hex, int timeout_seconds, blossom_blob_descriptor_t* descriptor_out);`
+  - `int blossom_upload_file_with_signer(const char* server_url, const char* file_path, const char* content_type, nostr_signer_t* signer, int timeout_seconds, blossom_blob_descriptor_t* descriptor_out);`
+  - `int blossom_delete_with_signer(const char* server_url, const char* sha256_hex, nostr_signer_t* signer, int timeout_seconds);`
+
+- Relay-pool NIP-42 AUTH entry point (`nostr_core/nostr_core.h`)
+  - `int nostr_relay_pool_set_auth_with_signer(nostr_relay_pool_t* pool, nostr_signer_t* signer, int enable);`
+
+### Driver app: `examples/note_poster`
+
+Signer modes:
+
+```bash
+./examples/note_poster
+```
+
+Default is local signer mode; this prompts for `nsec1...` or 64-char hex private key.
+
+**WARNING:** test-key-only flow. Do not use a production key; input key material is held in process memory in plaintext.
+
+```bash
+./examples/note_poster --signer unix:<name>
+./examples/note_poster --signer serial:/dev/ttyACM0
+./examples/note_poster --signer tcp:<host>:<port>
+./examples/note_poster --signer fds:<read_fd>:<write_fd>
+```
+
+### Boundaries / what stays in n_signer
+
+`nostr_core_lib` provides the **client side only** (transports + nsigner client + signer backends). The following stay in the `n_signer` project:
+
+- process spawning/embedding and deployment packaging
+- signer program trust-boundary features (mnemonic handling, approvals, role policy)
+- hardware firmware and platform/device-specific runtime pieces
+
+Dependency direction remains one-way: **`n_signer -> nostr_core_lib`**.
+
+Operations requiring raw secret material outside signer verbs are not remotable as-is. Example: mint-protocol operations in Cashu mint pieces (`cashu_mint`) that require direct secret access beyond event signing/NIP-04/NIP-44.
+
+For implementation plan context see `plans/nsigner_integration_plan.md`. This integration supersedes per-project hand-rolled signer clients (future migration milestone M7).
+
 ## 📁 Examples
 
 The library includes comprehensive examples:
@@ -295,11 +521,14 @@ The library includes comprehensive examples:
 - **`mnemonic_derivation`** - NIP-06 key derivation
 - **`utility_functions`** - General utility demonstrations
 - **`input_detection`** - Input type detection and processing
+- **`relay_pool`** - Interactive relay pool and subscription testing
+- **`send_nip17_dm`** - NIP-17 private direct message send flow
+- **`nip46_remote_signer`** - NIP-46 remote signer flow and bunker URL generation
 - **`version_test`** - Library version information
 
-Run all examples:
+Build all examples:
 ```bash
-./build.sh examples
+./build.sh -e
 ls -la examples/
 ```
 
@@ -308,24 +537,19 @@ ls -la examples/
 The library includes extensive tests:
 
 ```bash
-# Run all tests
-./build.sh test
+# Build all test executables
+./build.sh -t
 
-# Individual test categories
-cd tests && make test
+# Run the new NIP-46 test
+./tests/nip46_test
+
+# Run selected tests
+./tests/nip44_test
+./tests/nip42_test
+./tests/nip17_test
 ```
 
-**Test Categories:**
-- **Core Functionality**: `simple_init_test`, `header_test`
-- **Cryptography**: `chacha20_test`, `nostr_crypto_test`
-- **NIP-04 Encryption**: `nip04_test`
-- **NIP-05 Identifiers**: `nip05_test`
-- **NIP-11 Relay Info**: `nip11_test`
-- **NIP-44 Encryption**: `nip44_test`, `nip44_debug_test`
-- **Key Derivation**: `nostr_test_bip32`
-- **Relay Communication**: `relay_pool_test`, `sync_test`
-- **HTTP/WebSocket**: `http_test`, `wss_test`
-- **Proof of Work**: `test_pow_loop`
+**Current test binaries live in [`tests/`](tests/) and are generated from `*_test.c` sources.**
 
 ## 🏗️ Integration
 
@@ -335,7 +559,7 @@ cd tests && make test
 
 2. **Copy required files to your project:**
    ```bash
-   cp libnostr_core.a /path/to/your/project/
+   cp libnostr_core_x64.a /path/to/your/project/
    cp nostr_core/nostr_core.h /path/to/your/project/
    ```
 
@@ -370,7 +594,7 @@ The `libnostr_core.a` library now uses **system dependencies** for all major cry
 
 **Complete linking example:**
 ```bash
-gcc your_app.c ./libnostr_core.a -lssl -lcrypto -lcurl -lsecp256k1 -lm -o your_app
+gcc your_app.c ./libnostr_core_x64.a -lz -ldl -lpthread -lm -lssl -lcrypto -lcurl -lsecp256k1 -o your_app
 ```
 
 **Check system dependencies:**
@@ -398,8 +622,8 @@ ldd your_app  # Shows linked system libraries
 ### Build Flags
 
 ```bash
-# Enable all logging
-make LOGGING_FLAGS="-DENABLE_FILE_LOGGING -DENABLE_WEBSOCKET_LOGGING -DENABLE_DEBUG_LOGGING"
+# Enable websocket and PoW debug emission (now callback-based)
+make LOGGING_FLAGS="-DENABLE_WEBSOCKET_LOGGING -DENABLE_DEBUG_LOGGING"
 
 # Debug build
 make debug
@@ -408,6 +632,40 @@ make debug
 make arm64
 ```
 
+### Logging Integration (Consumer-Controlled)
+
+`nostr_core_lib` now supports a callback logging API so host applications can route library logs into their own logger and destination.
+
+- API is exposed via [`nostr_core/nostr_log.h`](nostr_core/nostr_log.h)
+- Included automatically from [`nostr_core/nostr_core.h`](nostr_core/nostr_core.h)
+
+```c
+#include "nostr_core/nostr_core.h"
+
+static void my_log_cb(int level, const char* component, const char* message, void* user_data) {
+    (void)user_data;
+    fprintf(stderr, "[nostr][%s][%d] %s\n", component ? component : "unknown", level, message ? message : "");
+}
+
+int main(void) {
+    if (nostr_init() != NOSTR_SUCCESS) return 1;
+
+    nostr_set_log_callback(my_log_cb, NULL);
+    nostr_set_log_level(NOSTR_LOG_LEVEL_TRACE);
+
+    /* ... your code ... */
+
+    nostr_cleanup();
+    return 0;
+}
+```
+
+#### Migration Notes
+
+- Direct file logging to `debug.log` has been removed from websocket and NIP-13 internals.
+- To receive logs, register a callback with [`nostr_set_log_callback()`](nostr_core/nostr_log.h:24).
+- Use [`nostr_set_log_level()`](nostr_core/nostr_log.h:25) to reduce verbosity in production.
+
 ## 🌐 Supported Platforms
 
 - **Linux** (x86_64, ARM64)
@@ -415,40 +673,59 @@ make arm64
 - **Windows** (MinGW, MSYS2)
 - **Embedded Systems** (resource-constrained environments)
 
+## 🔌 Embedded (ESP32) Support
+
+`nostr_core_lib` now includes a platform abstraction layer and ESP32-native implementations for core networking and entropy APIs, while preserving desktop compatibility.
+
+Implemented embedded capabilities include:
+- platform random source abstraction via `nostr_platform_random()`
+- ESP32 random provider using `esp_fill_random`
+- ESP32 HTTP client implementation via `esp_http_client`
+- ESP32 WebSocket/WSS transport via `esp_transport_ws` + TLS certificate bundle
+- NIP-04 encrypted DM flow validated on-device against public relays
+
+Reference ESP-IDF example project (in this workspace):
+- `../esp32_send_kind4/` — Wi-Fi connect + `wss://` relay connect + send two kind-4 encrypted events + print relay responses
+
 ## 📄 Documentation
 
-- **[LIBRARY_USAGE.md](LIBRARY_USAGE.md)** - Detailed integration guide
-- **[EXPORT_GUIDE.md](EXPORT_GUIDE.md)** - Library export instructions
-- **[AUTOMATIC_VERSIONING.md](AUTOMATIC_VERSIONING.md)** - Version management
-- **API Reference** - Complete documentation in `nostr_core/nostr_core.h`
+- **[POOL_API.md](POOL_API.md)** - Relay pool API notes
+- **[nostr_websocket/README.md](nostr_websocket/README.md)** - WebSocket module details
+- **[nostr_websocket/EXPORT_GUIDE.md](nostr_websocket/EXPORT_GUIDE.md)** - WebSocket export instructions
+- **API Reference** - Complete documentation in [`nostr_core/nostr_core.h`](nostr_core/nostr_core.h)
 
 ## 🤝 Contributing
 
 1. Fork the repository
 2. Create a feature branch: `git checkout -b feature/amazing-feature`
 3. Make your changes and add tests
-4. Run the test suite: `./build.sh test`
+4. Build tests and run key suites: `./build.sh -t && ./tests/nip46_test`
 5. Commit your changes: `git commit -m 'Add amazing feature'`
 6. Push to the branch: `git push origin feature/amazing-feature`
 7. Open a Pull Request
 
 ## 📈 Version History
 
-Current version: **0.1.20**
+Current version: **0.6.0**
 
 The library uses automatic semantic versioning based on Git tags. Each build increments the patch version automatically.
 
 **Recent Developments:**
-- **OpenSSL Migration**: Transitioned from mbedTLS to OpenSSL for improved compatibility
+- **ESP32 Embedded Enablement**: Added PAL-based embedded support directly in `nostr_core_lib`
+- **ESP32 HTTP + WSS**: Added ESP-IDF-backed HTTP and secure websocket transport implementations
+- **NIP-04 On-Device Validation**: Verified encrypted kind-4 DM publish flow from ESP32 to live relays
 - **NIP-05 Support**: DNS-based internet identifier verification
 - **NIP-11 Support**: Relay information document fetching and parsing
-- **Enhanced WebSocket**: OpenSSL-based TLS WebSocket communication
-- **Production Ready**: Comprehensive test suite and error handling
+- **NIP-19 Support**: Bech32-encoded entities (nsec/npub)
+- **Comprehensive Testing**: Extensive test suite and error handling
 
 **Version Timeline:**
+- `v0.6.x` - Embedded-capable releases with ESP32 PAL, HTTP, and WSS support
+- `v0.4.x` - Development releases with relay pool and expanded NIP support
+- `v0.2.x` - Earlier OpenSSL-based development releases
 - `v0.1.x` - Initial development releases
 - Focus on core protocol implementation and OpenSSL-based crypto
-- Full NIP-01, NIP-04, NIP-05, NIP-06, NIP-11, NIP-13, NIP-44 support
+- Full NIP-01, NIP-04, NIP-05, NIP-06, NIP-11, NIP-13, NIP-17, NIP-19, NIP-21, NIP-42, NIP-44, NIP-46, NIP-59 support
 
 ## 🐛 Troubleshooting
 
@@ -456,27 +733,35 @@ The library uses automatic semantic versioning based on Git tags. Each build inc
 
 **Build fails with secp256k1 errors:**
 ```bash
+# Install secp256k1 with Schnorr support
+sudo apt install libsecp256k1-dev    # Ubuntu/Debian
+# or
+sudo yum install libsecp256k1-devel  # CentOS/RHEL
+# or
+brew install secp256k1               # macOS
+
+# If still failing, build from source with Schnorr support:
+git clone https://github.com/bitcoin-core/secp256k1.git
 cd secp256k1
 ./autogen.sh
 ./configure --enable-module-schnorrsig --enable-module-ecdh
 make
-cd ..
-./build.sh lib
+sudo make install
 ```
 
-**Library too large:**
-The x64 library is intentionally large (~15MB) because it includes all secp256k1 cryptographic functions and OpenSSL for complete self-containment. The ARM64 library is smaller (~2.4MB) as it links against system OpenSSL.
+**Library size:**
+The library is small (~500KB) as it links against system libraries (secp256k1, OpenSSL, curl) rather than including them statically. This keeps the binary size manageable while maintaining full functionality.
 
 **Linking errors:**
 Make sure to include the math library:
 ```bash
-gcc your_code.c ./libnostr_core.a -lm  # Note the -lm flag
+gcc your_code.c ./libnostr_core_x64.a -lz -ldl -lpthread -lm -lssl -lcrypto -lcurl -lsecp256k1
 ```
 
 ### Getting Help
 
 - Check the `examples/` directory for working code
-- Run `./build.sh test` to verify your environment
+- Run `./build.sh -t` to verify your environment
 - Review the comprehensive API documentation in `nostr_core/nostr_core.h`
 
 ## 📜 License
@@ -496,4 +781,4 @@ This project is licensed under the MIT License - see the [LICENSE](LICENSE) file
 
 **Built with ❤️ for the decentralized web**
 
-*OpenSSL-based • Minimal dependencies • Production ready*
+*OpenSSL-based • Minimal dependencies • Work in progress*

UPSTREAM_VERSION

@@ -0,0 +1 @@
+0.6.6

VERSION

@@ -1 +1 @@
-0.1.33
+0.6.11

build.sh

@@ -58,6 +58,7 @@ FORCE_NIPS=""
 VERBOSE=false
 HELP=false
 BUILD_TESTS=false
+BUILD_EXAMPLES=false
 NO_COLOR_FLAG=false
 
 # Parse command line arguments
@@ -83,6 +84,10 @@ while [[ $# -gt 0 ]]; do
             BUILD_TESTS=true
             shift
             ;;
+        --examples|-e)
+            BUILD_EXAMPLES=true
+            shift
+            ;;
         --no-color)
             NO_COLOR_FLAG=true
             shift
@@ -119,6 +124,7 @@ if [ "$HELP" = true ]; then
     echo "  --nips=1,5,6,19       Force specific NIPs (comma-separated)"
     echo "  --nips=all            Include all available NIPs"
     echo "  --tests, -t           Build all test programs in tests/ directory"
+    echo "  --examples, -e        Build all example programs in examples/ directory"
     echo "  --verbose, -v         Verbose output"
     echo "  --no-color            Disable colored output"
     echo "  --help, -h            Show this help"
@@ -129,13 +135,21 @@ if [ "$HELP" = true ]; then
     echo ""
     echo "Available NIPs:"
     echo "  001 - Basic Protocol (event creation, signing)"
+    echo "  003 - OpenTimestamps"
     echo "  004 - Encryption (legacy)"
     echo "  005 - DNS-based identifiers"
     echo "  006 - Key derivation from mnemonic"
     echo "  011 - Relay information document"
     echo "  013 - Proof of Work"
+    echo "  017 - Private Direct Messages"
     echo "  019 - Bech32 encoding (nsec/npub)"
+    echo "  021 - nostr: URI scheme"
+    echo "  042 - Authentication of clients to relays"
     echo "  044 - Encryption (modern)"
+    echo "  046 - Remote signing"
+    echo "  059 - Gift Wrap"
+    echo "  060 - Cashu Wallet"
+    echo "  061 - Nutzaps"
     echo ""
     echo "Examples:"
     echo "  $0                    # Auto-detect NIPs, build for current arch"
@@ -166,7 +180,7 @@ if [ "$CURRENT_DIR" != "nostr_core_lib" ]; then
     echo "  cd nostr_core_lib"
     echo "  ./build.sh"
     echo "  cd .."
-    echo "  gcc your_app.c nostr_core_lib/libnostr_core_x64.a -lz -ldl -lpthread -lm -lssl -lcrypto -lcurl -o your_app"
+    echo "  gcc your_app.c nostr_core_lib/libnostr_core_x64.a -lz -ldl -lpthread -lm -lssl -lcrypto -lcurl -lsecp256k1 -o your_app"
     echo ""
     exit 1
 fi
@@ -184,7 +198,7 @@ print_info "Auto-detecting needed NIPs from your source code..."
 NEEDED_NIPS=""
 if [ -n "$FORCE_NIPS" ]; then
     if [ "$FORCE_NIPS" = "all" ]; then
-        NEEDED_NIPS="001 004 005 006 011 013 019 044"
+        NEEDED_NIPS="001 003 004 005 006 011 013 017 019 021 042 044 046 059 060 061"
         print_info "Forced: Building all available NIPs"
     else
         # Convert comma-separated list to space-separated with 3-digit format
@@ -203,7 +217,7 @@ else
         # Check for nostr_core.h (includes everything)
         if grep -q '#include[[:space:]]*["\<]nostr_core\.h["\>]' *.c 2>/dev/null; then
             print_info "Found #include \"nostr_core.h\" - building all NIPs"
-            NEEDED_NIPS="001 004 005 006 011 013 019 044"
+            NEEDED_NIPS="001 003 004 005 006 011 013 019 021 042 044 046 059 060 061"
         elif [ -n "$DETECTED" ]; then
             NEEDED_NIPS="$DETECTED"
             print_success "Auto-detected NIPs: $(echo $NEEDED_NIPS | tr ' ' ',')"
@@ -219,10 +233,10 @@ else
     fi
 fi
 
-# If building tests, include all NIPs to ensure test compatibility
-if [ "$BUILD_TESTS" = true ] && [ -z "$FORCE_NIPS" ]; then
-    NEEDED_NIPS="001 004 005 006 011 013 019 044"
-    print_info "Building tests - including all available NIPs for test compatibility"
+# If building tests or examples, include all NIPs to ensure compatibility
+if ([ "$BUILD_TESTS" = true ] || [ "$BUILD_EXAMPLES" = true ]) && [ -z "$FORCE_NIPS" ]; then
+    NEEDED_NIPS="001 003 004 005 006 011 013 017 019 021 042 044 046 059 060 061"
+    print_info "Building tests/examples - including all available NIPs for compatibility"
 fi
 
 # Ensure NIP-001 is always included (required for core functionality)
@@ -484,13 +498,23 @@ detect_system_curl
 ###########################################################################################
 
 SOURCES="nostr_core/crypto/nostr_secp256k1.c"
-SOURCES="$SOURCES nostr_core/crypto/nostr_aes.c"  
+SOURCES="$SOURCES nostr_core/crypto/nostr_aes.c"
 SOURCES="$SOURCES nostr_core/crypto/nostr_chacha20.c"
+SOURCES="$SOURCES nostr_core/crypto/nostr_poly1305.c"
+SOURCES="$SOURCES nostr_core/crypto/nostr_chacha20poly1305.c"
 SOURCES="$SOURCES cjson/cJSON.c"
 SOURCES="$SOURCES nostr_core/utils.c"
 SOURCES="$SOURCES nostr_core/nostr_common.c"
+SOURCES="$SOURCES nostr_core/nostr_signer.c"
 SOURCES="$SOURCES nostr_core/core_relays.c"
+SOURCES="$SOURCES nostr_core/core_relay_pool.c"
+SOURCES="$SOURCES nostr_core/nostr_log.c"
 SOURCES="$SOURCES nostr_websocket/nostr_websocket_openssl.c"
+SOURCES="$SOURCES nostr_core/request_validator.c"
+SOURCES="$SOURCES nostr_core/nostr_http.c"
+SOURCES="$SOURCES platform/linux.c"
+SOURCES="$SOURCES nostr_core/nsigner_transport.c"
+SOURCES="$SOURCES nostr_core/nsigner_client.c"
 
 NIP_DESCRIPTIONS=""
 
@@ -500,22 +524,37 @@ for nip in $NEEDED_NIPS; do
         SOURCES="$SOURCES $NIP_FILE"
         case $nip in
             001) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-001(Basic)" ;;
+            003) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-003(OpenTimestamps)" ;;
             004) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-004(Encrypt)" ;;
             005) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-005(DNS)" ;;
             006) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-006(Keys)" ;;
             011) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-011(Relay-Info)" ;;
             013) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-013(PoW)" ;;
+            017) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-017(DMs)" ;;
             019) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-019(Bech32)" ;;
+            021) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-021(URI)" ;;
+            042) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-042(Auth)" ;;
             044) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-044(Encrypt)" ;;
+            046) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-046(Remote-Signing)" ;;
+            059) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-059(Gift-Wrap)" ;;
+            060) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-060(Cashu-Wallet)" ;;
+            061) NIP_DESCRIPTIONS="$NIP_DESCRIPTIONS NIP-061(Nutzaps)" ;;
         esac
     else
         print_warning "NIP file not found: $NIP_FILE - skipping"
     fi
 done
 
+if echo "$NEEDED_NIPS" | grep -Eq '(^| )060( |$)|(^| )061( |$)'; then
+    SOURCES="$SOURCES nostr_core/cashu_mint.c"
+fi
+
+SOURCES="$SOURCES nostr_core/blossom_client.c"
+
 # Build flags
 CFLAGS="-Wall -Wextra -std=c99 -fPIC -O2"
 CFLAGS="$CFLAGS -DENABLE_FILE_LOGGING -DENABLE_WEBSOCKET_LOGGING -DENABLE_DEBUG_LOGGING"
+CFLAGS="$CFLAGS -DNOSTR_ENABLE_NSIGNER_CLIENT=1"
 INCLUDES="-I. -Inostr_core -Inostr_core/crypto -Icjson -Inostr_websocket"
 
 # Add system library includes
@@ -663,7 +702,53 @@ if [ $AR_RESULT -eq 0 ]; then
         fi
         echo ""
     fi
-    
+
+    # Build examples if requested
+    if [ "$BUILD_EXAMPLES" = true ]; then
+        print_info "Scanning examples/ directory for example programs..."
+
+        if [ ! -d "examples" ]; then
+            print_warning "examples/ directory not found - skipping example builds"
+        else
+            EXAMPLE_COUNT=0
+            SUCCESS_COUNT=0
+
+            # Find all .c files in examples/ directory (not subdirectories)
+            while IFS= read -r -d '' example_file; do
+                EXAMPLE_COUNT=$((EXAMPLE_COUNT + 1))
+                example_name=$(basename "$example_file" .c)
+                example_exe="examples/$example_name"
+
+                print_info "Building example: $example_name"
+
+                # Example compilation with system libraries
+                LINK_FLAGS="-lz -ldl -lpthread -lm $SYSTEM_LIBS"
+
+                if [ "$VERBOSE" = true ]; then
+                    print_info "  Command: $CC $CFLAGS $INCLUDES \"$example_file\" -o \"$example_exe\" ./$OUTPUT $LINK_FLAGS"
+                fi
+
+                if $CC $CFLAGS $INCLUDES "$example_file" -o "$example_exe" "./$OUTPUT" $LINK_FLAGS; then
+                    SUCCESS_COUNT=$((SUCCESS_COUNT + 1))
+                    print_success "Built $example_name"
+                    if [ "$VERBOSE" = true ]; then
+                        print_info "  Executable: $example_exe"
+                    fi
+                else
+                    print_error "  Failed to build: $example_name"
+                fi
+
+            done < <(find examples/ -maxdepth 1 -name "*.c" -type f -print0)
+
+            if [ $EXAMPLE_COUNT -eq 0 ]; then
+                print_warning "No .c files found in examples/ directory"
+            else
+                print_success "Built $SUCCESS_COUNT/$EXAMPLE_COUNT example programs"
+            fi
+        fi
+        echo ""
+    fi
+
     echo "Usage in your project:"
     echo "  gcc your_app.c $OUTPUT -lz -ldl -lpthread -lm $SYSTEM_LIBS -o your_app"
     echo ""

dev_build.sh

@@ -1,394 +0,0 @@
-#!/bin/bash
-
-# NOSTR Core Library Build Script
-# Provides convenient build targets for the standalone library
-# Automatically increments patch version with each build
-
-set -e  # Exit on any error
-
-# Colors for output
-RED='\033[0;31m'
-GREEN='\033[0;32m'
-YELLOW='\033[1;33m'
-BLUE='\033[0;34m'
-NC='\033[0m' # No Color
-
-# Function to print colored output
-print_status() {
-    echo -e "${BLUE}[INFO]${NC} $1"
-}
-
-print_success() {
-    echo -e "${GREEN}[SUCCESS]${NC} $1"
-}
-
-print_warning() {
-    echo -e "${YELLOW}[WARNING]${NC} $1"
-}
-
-print_error() {
-    echo -e "${RED}[ERROR]${NC} $1"
-}
-
-# Function to automatically increment version
-increment_version() {
-    print_status "Incrementing version..."
-    
-    # Check if we're in a git repository
-    if ! git rev-parse --git-dir > /dev/null 2>&1; then
-        print_warning "Not in a git repository - skipping version increment"
-        return 0
-    fi
-    
-    # Get the highest version tag (not necessarily the most recent chronologically)
-    LATEST_TAG=$(git tag -l 'v*.*.*' | sort -V | tail -n 1 || echo "v0.1.0")
-    if [[ -z "$LATEST_TAG" ]]; then
-        LATEST_TAG="v0.1.0"
-    fi
-    
-    # Extract version components (remove 'v' prefix if present)
-    VERSION=${LATEST_TAG#v}
-    
-    # Parse major.minor.patch
-    if [[ $VERSION =~ ^([0-9]+)\.([0-9]+)\.([0-9]+)$ ]]; then
-        MAJOR=${BASH_REMATCH[1]}
-        MINOR=${BASH_REMATCH[2]}
-        PATCH=${BASH_REMATCH[3]}
-    else
-        print_error "Invalid version format in tag: $LATEST_TAG"
-        print_error "Expected format: v0.1.0"
-        return 1
-    fi
-    
-    # Increment patch version
-    NEW_PATCH=$((PATCH + 1))
-    NEW_VERSION="v${MAJOR}.${MINOR}.${NEW_PATCH}"
-    
-    print_status "Current version: $LATEST_TAG"
-    print_status "New version: $NEW_VERSION"
-    
-    # Create new git tag
-    if git tag "$NEW_VERSION" 2>/dev/null; then
-        print_success "Created new version tag: $NEW_VERSION"
-    else
-        print_warning "Tag $NEW_VERSION already exists - using existing version"
-        NEW_VERSION=$LATEST_TAG
-    fi
-    
-    # Update VERSION file for compatibility
-    echo "${NEW_VERSION#v}" > VERSION
-    print_success "Updated VERSION file to ${NEW_VERSION#v}"
-}
-
-# Function to perform git operations after successful build
-perform_git_operations() {
-    local commit_message="$1"
-    
-    if [[ -z "$commit_message" ]]; then
-        return 0  # No commit message provided, skip git operations
-    fi
-    
-    print_status "Performing git operations..."
-    
-    # Check if we're in a git repository
-    if ! git rev-parse --git-dir > /dev/null 2>&1; then
-        print_warning "Not in a git repository - skipping git operations"
-        return 0
-    fi
-    
-    # Check if there are changes to commit
-    if git diff --quiet && git diff --cached --quiet; then
-        print_warning "No changes to commit"
-        return 0
-    fi
-    
-    # Add all changes
-    print_status "Adding changes to git..."
-    if ! git add .; then
-        print_error "Failed to add changes to git"
-        return 1
-    fi
-    
-    # Commit changes
-    print_status "Committing changes with message: '$commit_message'"
-    if ! git commit -m "$commit_message"; then
-        print_error "Failed to commit changes"
-        return 1
-    fi
-    
-    # Push changes
-    print_status "Pushing changes to remote repository..."
-    if ! git push; then
-        print_error "Failed to push changes to remote repository"
-        print_warning "Changes have been committed locally but not pushed"
-        return 1
-    fi
-    
-    print_success "Git operations completed successfully!"
-    return 0
-}
-
-# Function to show usage
-show_usage() {
-    echo "NOSTR Core Library Build Script"
-    echo "==============================="
-    echo ""
-    echo "Usage: $0 [target] [-m \"commit message\"]"
-    echo ""
-    echo "Available targets:"
-    echo "  clean       - Clean all build artifacts"
-    echo "  lib         - Build static libraries for both x64 and ARM64 (default)"
-    echo "  x64         - Build x64 static library only"
-    echo "  arm64       - Build ARM64 static library only"
-    echo "  all         - Build both architectures and examples"
-    echo "  examples    - Build example programs"
-    echo "  test        - Run tests"
-    echo "  install     - Install library to system"
-    echo "  uninstall   - Remove library from system"
-    echo "  help        - Show this help message"
-    echo ""
-    echo "Options:"
-    echo "  -m \"message\"  - Git commit message (triggers automatic git add, commit, push after successful build)"
-    echo ""
-    echo "Examples:"
-    echo "  $0 lib -m \"Add new proof-of-work parameters\""
-    echo "  $0 x64 -m \"Fix OpenSSL minimal build configuration\""
-    echo "  $0 lib                                        # Build without git operations"
-    echo ""
-    echo "Library outputs (both self-contained with secp256k1):"
-    echo "  libnostr_core.a       - x86_64 static library"
-    echo "  libnostr_core_arm64.a - ARM64 static library"
-    echo "  examples/*            - Example programs"
-    echo ""
-    echo "Both libraries include secp256k1 objects internally."
-    echo "Users only need to link with the library + -lm."
-}
-
-# Parse command line arguments
-TARGET=""
-COMMIT_MESSAGE=""
-
-# Parse arguments
-while [[ $# -gt 0 ]]; do
-    case $1 in
-        -m)
-            COMMIT_MESSAGE="$2"
-            shift 2
-            ;;
-        -*)
-            print_error "Unknown option: $1"
-            show_usage
-            exit 1
-            ;;
-        *)
-            if [[ -z "$TARGET" ]]; then
-                TARGET="$1"
-            else
-                print_error "Multiple targets specified: $TARGET and $1"
-                show_usage
-                exit 1
-            fi
-            shift
-            ;;
-    esac
-done
-
-# Set default target if none specified
-TARGET=${TARGET:-lib}
-
-case "$TARGET" in
-    clean)
-        print_status "Cleaning build artifacts..."
-        make clean
-        print_success "Clean completed"
-        ;;
-        
-    lib|library)
-        increment_version
-        print_status "Building both x64 and ARM64 static libraries..."
-        make clean
-        make
-        
-        # Check both libraries were built
-        SUCCESS=0
-        if [ -f "libnostr_core.a" ]; then
-            SIZE_X64=$(stat -c%s "libnostr_core.a")
-            print_success "x64 static library built successfully (${SIZE_X64} bytes)"
-            SUCCESS=$((SUCCESS + 1))
-        else
-            print_error "Failed to build x64 static library"
-        fi
-        
-        if [ -f "libnostr_core_arm64.a" ]; then
-            SIZE_ARM64=$(stat -c%s "libnostr_core_arm64.a")
-            print_success "ARM64 static library built successfully (${SIZE_ARM64} bytes)"
-            SUCCESS=$((SUCCESS + 1))
-        else
-            print_error "Failed to build ARM64 static library"
-        fi
-        
-        if [ $SUCCESS -eq 2 ]; then
-            print_success "Both architectures built successfully!"
-            ls -la libnostr_core*.a
-            perform_git_operations "$COMMIT_MESSAGE"
-        else
-            print_error "Failed to build all libraries"
-            exit 1
-        fi
-        ;;
-        
-    x64|x64-only)
-        increment_version
-        print_status "Building x64 static library only..."
-        make clean
-        make x64
-        if [ -f "libnostr_core.a" ]; then
-            SIZE=$(stat -c%s "libnostr_core.a")
-            print_success "x64 static library built successfully (${SIZE} bytes)"
-            ls -la libnostr_core.a
-            perform_git_operations "$COMMIT_MESSAGE"
-        else
-            print_error "Failed to build x64 static library"
-            exit 1
-        fi
-        ;;
-        
-    arm64|arm64-only)
-        increment_version
-        print_status "Building ARM64 static library only..."
-        make clean
-        make arm64
-        if [ -f "libnostr_core_arm64.a" ]; then
-            SIZE=$(stat -c%s "libnostr_core_arm64.a")
-            print_success "ARM64 static library built successfully (${SIZE} bytes)"
-            ls -la libnostr_core_arm64.a
-            perform_git_operations "$COMMIT_MESSAGE"
-        else
-            print_error "Failed to build ARM64 static library"
-            exit 1
-        fi
-        ;;
-        
-    shared)
-        increment_version
-        print_status "Building shared library..."
-        make clean
-        make libnostr_core.so
-        if [ -f "libnostr_core.so" ]; then
-            SIZE=$(stat -c%s "libnostr_core.so")
-            print_success "Shared library built successfully (${SIZE} bytes)"
-            ls -la libnostr_core.so
-            perform_git_operations "$COMMIT_MESSAGE"
-        else
-            print_error "Failed to build shared library"
-            exit 1
-        fi
-        ;;
-        
-    all)
-        increment_version
-        print_status "Building all libraries and examples..."
-        make clean
-        make all
-        
-        # Check both libraries and examples were built
-        SUCCESS=0
-        if [ -f "libnostr_core.a" ]; then
-            SIZE_X64=$(stat -c%s "libnostr_core.a")
-            print_success "x64 static library built successfully (${SIZE_X64} bytes)"
-            SUCCESS=$((SUCCESS + 1))
-        else
-            print_error "Failed to build x64 static library"
-        fi
-        
-        if [ -f "libnostr_core_arm64.a" ]; then
-            SIZE_ARM64=$(stat -c%s "libnostr_core_arm64.a")
-            print_success "ARM64 static library built successfully (${SIZE_ARM64} bytes)"
-            SUCCESS=$((SUCCESS + 1))
-        else
-            print_error "Failed to build ARM64 static library"
-        fi
-        
-        if [ $SUCCESS -eq 2 ]; then
-            print_success "All libraries and examples built successfully!"
-            ls -la libnostr_core*.a
-            ls -la examples/
-            perform_git_operations "$COMMIT_MESSAGE"
-        else
-            print_error "Failed to build all components"
-            exit 1
-        fi
-        ;;
-        
-    examples)
-        increment_version
-        print_status "Building both libraries and examples..."
-        make clean
-        make
-        make examples
-        
-        # Verify libraries were built
-        if [ -f "libnostr_core.a" ] && [ -f "libnostr_core_arm64.a" ]; then
-            print_success "Both libraries and examples built successfully"
-            ls -la libnostr_core*.a
-            ls -la examples/
-            perform_git_operations "$COMMIT_MESSAGE"
-        else
-            print_error "Failed to build libraries for examples"
-            exit 1
-        fi
-        ;;
-        
-    test)
-        print_status "Running tests..."
-        make clean
-        make
-        if make test-crypto 2>/dev/null; then
-            print_success "All tests passed"
-        else
-            print_warning "Running simple test instead..."
-            make test
-            print_success "Basic test completed"
-        fi
-        ;;
-        
-    tests)
-        print_status "Running tests..."
-        make clean
-        make
-        if make test-crypto 2>/dev/null; then
-            print_success "All tests passed"
-        else
-            print_warning "Running simple test instead..."
-            make test
-            print_success "Basic test completed"
-        fi
-        ;;
-
-    install)
-        increment_version
-        print_status "Installing library to system..."
-        make clean
-        make all
-        sudo make install
-        print_success "Library installed to /usr/local"
-        perform_git_operations "$COMMIT_MESSAGE"
-        ;;
-        
-    uninstall)
-        print_status "Uninstalling library from system..."
-        sudo make uninstall
-        print_success "Library uninstalled"
-        ;;
-        
-    help|--help|-h)
-        show_usage
-        ;;
-        
-    *)
-        print_error "Unknown target: $TARGET"
-        echo ""
-        show_usage
-        exit 1
-        ;;
-esac

examples/cashu_wallet.c

@@ -0,0 +1,121 @@
+/*
+ * Example: NIP-60/NIP-61 Cashu Wallet Flow
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include "../nostr_core/nostr_core.h"
+
+static void print_event(const char* title, cJSON* evt) {
+    if (!evt) {
+        printf("%s: <null>\n", title);
+        return;
+    }
+    char* s = cJSON_Print(evt);
+    if (s) {
+        printf("\n%s\n%s\n", title, s);
+        free(s);
+    }
+}
+
+int main(void) {
+    if (nostr_init() != NOSTR_SUCCESS) {
+        printf("Failed to initialize library\n");
+        return 1;
+    }
+
+    const char* user_sk_hex = "91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe";
+    unsigned char user_sk[32];
+    if (nostr_hex_to_bytes(user_sk_hex, user_sk, 32) != 0) {
+        printf("Invalid private key\n");
+        nostr_cleanup();
+        return 1;
+    }
+
+    /* 1) Create wallet event (kind:17375) */
+    char* mint_urls[] = {
+        "https://mint1.example.com",
+        "https://mint2.example.com"
+    };
+
+    nostr_nip60_wallet_data_t wallet_data;
+    memset(&wallet_data, 0, sizeof(wallet_data));
+    strcpy(wallet_data.privkey, "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
+    wallet_data.mint_urls = mint_urls;
+    wallet_data.mint_count = 2;
+
+    cJSON* wallet_event = nostr_nip60_create_wallet_event(&wallet_data, user_sk, 0);
+    print_event("Wallet Event (kind:17375)", wallet_event);
+
+    /* 2) Create token event (kind:7375) */
+    nostr_cashu_proof_t proofs[2];
+    memset(proofs, 0, sizeof(proofs));
+
+    strcpy(proofs[0].id, "005c2502034d4f12");
+    proofs[0].amount = 1;
+    proofs[0].secret = "secret-1";
+    proofs[0].C = "0241d98a8197ef238a192d47edf191a9de78b657308937b4f7dd0aa53beae72c46";
+
+    strcpy(proofs[1].id, "005c2502034d4f12");
+    proofs[1].amount = 2;
+    proofs[1].secret = "secret-2";
+    proofs[1].C = "02277c66191736eb72fce9d975d08e3191f8f96afb73ab1eec37e4465683066d3f";
+
+    nostr_nip60_token_data_t token_data;
+    memset(&token_data, 0, sizeof(token_data));
+    token_data.mint_url = "https://mint1.example.com";
+    token_data.proofs = proofs;
+    token_data.proof_count = 2;
+
+    cJSON* token_event = nostr_nip60_create_token_event(&token_data, user_sk, 0);
+    print_event("Token Event (kind:7375)", token_event);
+
+    /* 3) Create spend history event (kind:7376) */
+    nostr_nip60_history_ref_t refs[1];
+    memset(refs, 0, sizeof(refs));
+    strcpy(refs[0].event_id, "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
+    refs[0].marker = NOSTR_NIP60_REF_CREATED;
+
+    nostr_nip60_history_data_t hist;
+    memset(&hist, 0, sizeof(hist));
+    hist.direction = NOSTR_NIP60_DIRECTION_IN;
+    hist.amount = 3;
+    hist.refs = refs;
+    hist.ref_count = 1;
+
+    cJSON* history_event = nostr_nip60_create_history_event(&hist, user_sk, 0);
+    print_event("History Event (kind:7376)", history_event);
+
+    /* 4) Create nutzap info event (kind:10019) */
+    char* relays[] = {"wss://relay1.example.com", "wss://relay2.example.com"};
+    char* mint_units[] = {"sat"};
+
+    nostr_nip61_mint_entry_t mint_entry;
+    memset(&mint_entry, 0, sizeof(mint_entry));
+    mint_entry.url = "https://mint1.example.com";
+    mint_entry.units = mint_units;
+    mint_entry.unit_count = 1;
+
+    nostr_nip61_nutzap_info_t info;
+    memset(&info, 0, sizeof(info));
+    info.relay_urls = relays;
+    info.relay_count = 2;
+    info.mints = &mint_entry;
+    info.mint_count = 1;
+    strcpy(info.pubkey, "02eaee8939e3565e48cc62967e2fde9d8e2a4b3ec0081f29eceff5c64ef10ac1ed");
+
+    cJSON* info_event = nostr_nip61_create_nutzap_info_event(&info, user_sk, 0);
+    print_event("Nutzap Info Event (kind:10019)", info_event);
+
+    /* 5) Optionally call Cashu mint HTTP endpoints with [cashu_mint_get_info()] */
+    printf("\nCashu mint integration is available via cashu_mint_* APIs.\n");
+
+    cJSON_Delete(info_event);
+    cJSON_Delete(history_event);
+    cJSON_Delete(token_event);
+    cJSON_Delete(wallet_event);
+
+    nostr_cleanup();
+    return 0;
+}

examples/integration_example/CMakeLists.txt

@@ -1,39 +0,0 @@
-# Example CMakeLists.txt for a project using nostr_core library
-cmake_minimum_required(VERSION 3.12)
-project(my_nostr_app VERSION 1.0.0 LANGUAGES C)
-
-set(CMAKE_C_STANDARD 99)
-
-# Method 1: Find installed package
-# Uncomment if nostr_core is installed system-wide
-# find_package(nostr_core REQUIRED)
-
-# Method 2: Use as subdirectory
-# Uncomment if nostr_core is a subdirectory
-# add_subdirectory(nostr_core)
-
-# Method 3: Use pkg-config
-# Uncomment if using pkg-config
-# find_package(PkgConfig REQUIRED)
-# pkg_check_modules(NOSTR_CORE REQUIRED nostr_core)
-
-# Create executable
-add_executable(my_nostr_app main.c)
-
-# Link with nostr_core
-# Choose one of the following based on your integration method:
-
-# Method 1: Installed package
-# target_link_libraries(my_nostr_app nostr_core::static)
-
-# Method 2: Subdirectory
-# target_link_libraries(my_nostr_app nostr_core_static)
-
-# Method 3: pkg-config
-# target_include_directories(my_nostr_app PRIVATE ${NOSTR_CORE_INCLUDE_DIRS})
-# target_link_libraries(my_nostr_app ${NOSTR_CORE_LIBRARIES})
-
-# For this example, we'll assume Method 2 (subdirectory)
-# Add the parent nostr_core directory
-add_subdirectory(../.. nostr_core)
-target_link_libraries(my_nostr_app nostr_core_static)

examples/integration_example/README.md

@@ -1,186 +0,0 @@
-# NOSTR Core Integration Example
-
-This directory contains a complete example showing how to integrate the NOSTR Core library into your own projects.
-
-## What This Example Demonstrates
-
-- **Library Initialization**: Proper setup and cleanup of the NOSTR library
-- **Identity Management**: Key generation, bech32 encoding, and format detection
-- **Event Creation**: Creating and signing different types of NOSTR events
-- **Input Handling**: Processing various input formats (mnemonic, hex, bech32)
-- **Utility Functions**: Using helper functions for hex conversion and error handling
-- **CMake Integration**: How to integrate the library in your CMake-based project
-
-## Building and Running
-
-### Method 1: Using CMake
-
-```bash
-# Create build directory
-mkdir build && cd build
-
-# Configure with CMake
-cmake ..
-
-# Build
-make
-
-# Run the example
-./my_nostr_app
-```
-
-### Method 2: Manual Compilation
-
-```bash
-# Compile directly (assuming you're in the c_nostr root directory)
-gcc -I. examples/integration_example/main.c nostr_core.c nostr_crypto.c cjson/cJSON.c -lm -o integration_example
-
-# Run
-./integration_example
-```
-
-## Expected Output
-
-The example will demonstrate:
-
-1. **Identity Management Demo**
-   - Generate a new keypair
-   - Display keys in hex and bech32 format
-
-2. **Event Creation Demo**
-   - Create a text note event
-   - Create a profile event
-   - Display the JSON for both events
-
-3. **Input Handling Demo**
-   - Process different input formats
-   - Show format detection and decoding
-
-4. **Utility Functions Demo**
-   - Hex conversion round-trip
-   - Error message display
-
-## Integration Patterns
-
-### Pattern 1: CMake Find Package
-
-If NOSTR Core is installed system-wide:
-
-```cmake
-find_package(nostr_core REQUIRED)
-target_link_libraries(your_app nostr_core::static)
-```
-
-### Pattern 2: CMake Subdirectory
-
-If NOSTR Core is a subdirectory of your project:
-
-```cmake
-add_subdirectory(nostr_core)
-target_link_libraries(your_app nostr_core_static)
-```
-
-### Pattern 3: pkg-config
-
-If using pkg-config:
-
-```cmake
-find_package(PkgConfig REQUIRED)
-pkg_check_modules(NOSTR_CORE REQUIRED nostr_core)
-target_include_directories(your_app PRIVATE ${NOSTR_CORE_INCLUDE_DIRS})
-target_link_libraries(your_app ${NOSTR_CORE_LIBRARIES})
-```
-
-### Pattern 4: Direct Source Integration
-
-Copy the essential files to your project:
-
-```bash
-cp nostr_core.{c,h} nostr_crypto.{c,h} your_project/src/
-cp -r cjson/ your_project/src/
-```
-
-Then compile them with your project sources.
-
-## Code Structure
-
-### main.c Structure
-
-The example is organized into clear demonstration functions:
-
-- `demo_identity_management()` - Key generation and encoding
-- `demo_event_creation()` - Creating different event types
-- `demo_input_handling()` - Processing various input formats
-- `demo_utilities()` - Using utility functions
-
-Each function demonstrates specific aspects of the library while maintaining proper error handling and resource cleanup.
-
-### Key Integration Points
-
-1. **Initialization**
-   ```c
-   int ret = nostr_init();
-   if (ret != NOSTR_SUCCESS) {
-       // Handle error
-   }
-   ```
-
-2. **Resource Cleanup**
-   ```c
-   // Always clean up JSON objects
-   cJSON_Delete(event);
-   
-   // Clean up library on exit
-   nostr_cleanup();
-   ```
-
-3. **Error Handling**
-   ```c
-   if (ret != NOSTR_SUCCESS) {
-       printf("Error: %s\n", nostr_strerror(ret));
-       return ret;
-   }
-   ```
-
-## Customization
-
-You can modify this example for your specific needs:
-
-- Change the `app_config_t` structure to match your application's configuration
-- Add additional event types or custom event creation logic
-- Integrate with your existing error handling and logging systems
-- Add networking functionality using the WebSocket layer
-
-## Dependencies
-
-This example requires:
-- C99 compiler (gcc, clang)
-- CMake 3.12+ (for CMake build)
-- NOSTR Core library and its dependencies
-
-## Testing
-
-You can test different input formats by passing them as command line arguments:
-
-```bash
-# Test with mnemonic
-./my_nostr_app "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
-
-# Test with hex private key
-./my_nostr_app "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
-
-# Test with bech32 nsec
-./my_nostr_app "nsec1xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-```
-
-## Next Steps
-
-After studying this example, you can:
-
-1. Integrate the patterns into your own application
-2. Explore the WebSocket functionality for relay communication
-3. Add support for additional NOSTR event types
-4. Implement your own identity persistence layer
-5. Add networking and relay management features
-
-For more examples, see the other files in the `examples/` directory.

examples/integration_example/main.c

@@ -1,271 +0,0 @@
-/*
- * Example application demonstrating how to integrate nostr_core into other projects
- * This shows a complete workflow from key generation to event publishing
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include "nostr_core.h"
-
-// Example application configuration
-typedef struct {
-    char* app_name;
-    char* version;
-    int debug_mode;
-} app_config_t;
-
-static app_config_t g_config = {
-    .app_name = "My NOSTR App",
-    .version = "1.0.0",
-    .debug_mode = 1
-};
-
-// Helper function to print hex data
-static void print_hex(const char* label, const unsigned char* data, size_t len) {
-    if (g_config.debug_mode) {
-        printf("%s: ", label);
-        for (size_t i = 0; i < len; i++) {
-            printf("%02x", data[i]);
-        }
-        printf("\n");
-    }
-}
-
-// Helper function to print JSON nicely
-static void print_event(const char* label, cJSON* event) {
-    if (!event) {
-        printf("%s: NULL\n", label);
-        return;
-    }
-    
-    char* json_string = cJSON_Print(event);
-    if (json_string) {
-        printf("%s:\n%s\n", label, json_string);
-        free(json_string);
-    }
-}
-
-// Example: Generate and manage identity
-static int demo_identity_management(void) {
-    printf("\n=== Identity Management Demo ===\n");
-    
-    unsigned char private_key[32], public_key[32];
-    char nsec[100], npub[100];
-    
-    // Generate a new keypair
-    printf("Generating new keypair...\n");
-    int ret = nostr_generate_keypair(private_key, public_key);
-    if (ret != NOSTR_SUCCESS) {
-        printf("Error generating keypair: %s\n", nostr_strerror(ret));
-        return ret;
-    }
-    
-    print_hex("Private Key", private_key, 32);
-    print_hex("Public Key", public_key, 32);
-    
-    // Convert to bech32 format
-    ret = nostr_key_to_bech32(private_key, "nsec", nsec);
-    if (ret != NOSTR_SUCCESS) {
-        printf("Error encoding nsec: %s\n", nostr_strerror(ret));
-        return ret;
-    }
-    
-    ret = nostr_key_to_bech32(public_key, "npub", npub);
-    if (ret != NOSTR_SUCCESS) {
-        printf("Error encoding npub: %s\n", nostr_strerror(ret));
-        return ret;
-    }
-    
-    printf("nsec: %s\n", nsec);
-    printf("npub: %s\n", npub);
-    
-    return NOSTR_SUCCESS;
-}
-
-// Example: Create different types of events
-static int demo_event_creation(const unsigned char* private_key) {
-    printf("\n=== Event Creation Demo ===\n");
-    
-    // Create a text note
-    printf("Creating text note...\n");
-    cJSON* text_event = nostr_create_text_event("Hello from my NOSTR app!", private_key);
-    if (!text_event) {
-        printf("Error creating text event\n");
-        return NOSTR_ERROR_JSON_PARSE;
-    }
-    print_event("Text Event", text_event);
-    
-    // Create a profile event
-    printf("\nCreating profile event...\n");
-    cJSON* profile_event = nostr_create_profile_event(
-        g_config.app_name, 
-        "A sample application demonstrating NOSTR integration",
-        private_key
-    );
-    if (!profile_event) {
-        printf("Error creating profile event\n");
-        cJSON_Delete(text_event);
-        return NOSTR_ERROR_JSON_PARSE;
-    }
-    print_event("Profile Event", profile_event);
-    
-    // Cleanup
-    cJSON_Delete(text_event);
-    cJSON_Delete(profile_event);
-    
-    return NOSTR_SUCCESS;
-}
-
-// Example: Handle different input formats
-static int demo_input_handling(const char* user_input) {
-    printf("\n=== Input Handling Demo ===\n");
-    printf("Processing input: %s\n", user_input);
-    
-    // Detect input type
-    int input_type = nostr_detect_input_type(user_input);
-    switch (input_type) {
-        case NOSTR_INPUT_MNEMONIC:
-            printf("Detected: BIP39 Mnemonic\n");
-            {
-                unsigned char priv[32], pub[32];
-                int ret = nostr_derive_keys_from_mnemonic(user_input, 0, priv, pub);
-                if (ret == NOSTR_SUCCESS) {
-                    print_hex("Derived Private Key", priv, 32);
-                    print_hex("Derived Public Key", pub, 32);
-                }
-            }
-            break;
-            
-        case NOSTR_INPUT_NSEC_HEX:
-            printf("Detected: Hex-encoded private key\n");
-            {
-                unsigned char decoded[32];
-                int ret = nostr_decode_nsec(user_input, decoded);
-                if (ret == NOSTR_SUCCESS) {
-                    print_hex("Decoded Private Key", decoded, 32);
-                }
-            }
-            break;
-            
-        case NOSTR_INPUT_NSEC_BECH32:
-            printf("Detected: Bech32-encoded private key (nsec)\n");
-            {
-                unsigned char decoded[32];
-                int ret = nostr_decode_nsec(user_input, decoded);
-                if (ret == NOSTR_SUCCESS) {
-                    print_hex("Decoded Private Key", decoded, 32);
-                }
-            }
-            break;
-            
-        default:
-            printf("Unknown input format\n");
-            return NOSTR_ERROR_INVALID_INPUT;
-    }
-    
-    return NOSTR_SUCCESS;
-}
-
-// Example: Demonstrate utility functions
-static int demo_utilities(void) {
-    printf("\n=== Utility Functions Demo ===\n");
-    
-    // Hex conversion
-    const char* test_hex = "deadbeef";
-    unsigned char bytes[4];
-    char hex_result[9];
-    
-    printf("Testing hex conversion with: %s\n", test_hex);
-    
-    int ret = nostr_hex_to_bytes(test_hex, bytes, 4);
-    if (ret != NOSTR_SUCCESS) {
-        printf("Error in hex_to_bytes: %s\n", nostr_strerror(ret));
-        return ret;
-    }
-    
-    nostr_bytes_to_hex(bytes, 4, hex_result);
-    printf("Round-trip result: %s\n", hex_result);
-    
-    // Error message testing
-    printf("\nTesting error messages:\n");
-    for (int i = 0; i >= -10; i--) {
-        const char* msg = nostr_strerror(i);
-        if (msg && strlen(msg) > 0) {
-            printf("  %d: %s\n", i, msg);
-        }
-    }
-    
-    return NOSTR_SUCCESS;
-}
-
-int main(int argc, char* argv[]) {
-    printf("%s v%s\n", g_config.app_name, g_config.version);
-    printf("NOSTR Core Integration Example\n");
-    printf("=====================================\n");
-    
-    // Initialize the NOSTR library
-    printf("Initializing NOSTR core library...\n");
-    int ret = nostr_init();
-    if (ret != NOSTR_SUCCESS) {
-        printf("Failed to initialize NOSTR library: %s\n", nostr_strerror(ret));
-        return 1;
-    }
-    
-    // Run demonstrations
-    unsigned char demo_private_key[32];
-    
-    // 1. Identity management
-    ret = demo_identity_management();
-    if (ret != NOSTR_SUCCESS) {
-        goto cleanup;
-    }
-    
-    // Generate a key for other demos
-    nostr_generate_keypair(demo_private_key, NULL);
-    
-    // 2. Event creation
-    ret = demo_event_creation(demo_private_key);
-    if (ret != NOSTR_SUCCESS) {
-        goto cleanup;
-    }
-    
-    // 3. Input handling (use command line argument if provided)
-    const char* test_input = (argc > 1) ? argv[1] : 
-        "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about";
-    ret = demo_input_handling(test_input);
-    if (ret != NOSTR_SUCCESS && ret != NOSTR_ERROR_INVALID_INPUT) {
-        goto cleanup;
-    }
-    
-    // 4. Utility functions
-    ret = demo_utilities();
-    if (ret != NOSTR_SUCCESS) {
-        goto cleanup;
-    }
-    
-    printf("\n=====================================\n");
-    printf("All demonstrations completed successfully!\n");
-    printf("\nThis example shows how to:\n");
-    printf("  • Initialize the NOSTR library\n");
-    printf("  • Generate and manage keypairs\n");
-    printf("  • Create and sign different event types\n");
-    printf("  • Handle various input formats\n");
-    printf("  • Use utility functions\n");
-    printf("  • Clean up resources properly\n");
-    
-    ret = NOSTR_SUCCESS;
-
-cleanup:
-    // Clean up the NOSTR library
-    printf("\nCleaning up NOSTR library...\n");
-    nostr_cleanup();
-    
-    if (ret == NOSTR_SUCCESS) {
-        printf("Example completed successfully.\n");
-        return 0;
-    } else {
-        printf("Example failed with error: %s\n", nostr_strerror(ret));
-        return 1;
-    }
-}

examples/nip46_remote_signer.c

@@ -0,0 +1,125 @@
+/*
+ * NIP-46 Remote Signer Example
+ *
+ * Demonstrates signer session setup, bunker URL generation,
+ * request parsing, request handling, and encrypted response event creation.
+ */
+
+#include "../nostr_core/nostr_core.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int parse_hex_key(const char* hex, unsigned char out[32]) {
+    if (!hex || strlen(hex) != 64) return -1;
+    return nostr_hex_to_bytes(hex, out, 32);
+}
+
+int main(int argc, char** argv) {
+    if (argc < 3) {
+        fprintf(stderr, "Usage: %s <signer_privkey_hex> <user_privkey_hex> [relay_url]\n", argv[0]);
+        fprintf(stderr, "Example: %s <64hex> <64hex> wss://relay.example.com\n", argv[0]);
+        return 1;
+    }
+
+    const char* relay = (argc >= 4) ? argv[3] : "wss://relay.example.com";
+
+    unsigned char signer_sk[32];
+    unsigned char user_sk[32];
+    if (parse_hex_key(argv[1], signer_sk) != 0 || parse_hex_key(argv[2], user_sk) != 0) {
+        fprintf(stderr, "Invalid private key hex; expected 64 hex characters for each key\n");
+        return 1;
+    }
+
+    if (nostr_init() != NOSTR_SUCCESS) {
+        fprintf(stderr, "Failed to initialize nostr library\n");
+        return 1;
+    }
+
+    const char* relays[] = { relay };
+    nostr_nip46_signer_session_t signer;
+    int rc = nostr_nip46_signer_session_init(&signer, signer_sk, user_sk, relays, 1);
+    if (rc != NOSTR_SUCCESS) {
+        fprintf(stderr, "signer init failed: %s\n", nostr_strerror(rc));
+        nostr_cleanup();
+        return 1;
+    }
+
+    char bunker_url[1024];
+    rc = nostr_nip46_signer_create_bunker_url(&signer, "demo-secret", bunker_url, sizeof(bunker_url));
+    if (rc != NOSTR_SUCCESS) {
+        fprintf(stderr, "failed to create bunker url: %s\n", nostr_strerror(rc));
+        nostr_nip46_signer_session_destroy(&signer);
+        nostr_cleanup();
+        return 1;
+    }
+
+    printf("NIP-46 signer initialized\n");
+    printf("Signer pubkey: %s\n", signer.signer_pubkey_hex);
+    printf("User pubkey:   %s\n", signer.user_pubkey_hex);
+    printf("Relay:         %s\n", relay);
+    printf("Bunker URL:    %s\n\n", bunker_url);
+
+    // Simulate receiving a connect request and producing a response
+    const char* connect_params[] = { signer.signer_pubkey_hex, "demo-secret", "sign_event:1,get_public_key" };
+    nostr_nip46_request_t req;
+    rc = nostr_nip46_create_request("demo-req-1", NOSTR_NIP46_METHOD_CONNECT, connect_params, 3, &req);
+    if (rc != NOSTR_SUCCESS) {
+        fprintf(stderr, "failed to create demo request: %s\n", nostr_strerror(rc));
+        nostr_nip46_signer_session_destroy(&signer);
+        nostr_cleanup();
+        return 1;
+    }
+
+    nostr_nip46_response_t resp;
+    rc = nostr_nip46_signer_handle_request(&signer, &req, &resp);
+    if (rc != NOSTR_SUCCESS) {
+        fprintf(stderr, "failed to handle demo request: %s\n", nostr_strerror(rc));
+        nostr_nip46_free_request(&req);
+        nostr_nip46_signer_session_destroy(&signer);
+        nostr_cleanup();
+        return 1;
+    }
+
+    printf("Handled method: %s\n", req.method_str);
+    printf("Response result: %s\n", resp.result ? resp.result : "<none>");
+    printf("Response error:  %s\n", resp.error ? resp.error : "<none>");
+
+    // Simulate building encrypted response event back to a client
+    unsigned char client_sk[32];
+    unsigned char client_pk[32];
+    memset(client_sk, 0, sizeof(client_sk));
+    client_sk[31] = 1; // deterministic demo key
+    if (nostr_ec_public_key_from_private_key(client_sk, client_pk) != 0) {
+        fprintf(stderr, "failed to derive demo client pubkey\n");
+        nostr_nip46_free_response(&resp);
+        nostr_nip46_free_request(&req);
+        nostr_nip46_signer_session_destroy(&signer);
+        nostr_cleanup();
+        return 1;
+    }
+
+    cJSON* response_event = nostr_nip46_create_response_event(&resp, signer.signer_private_key, client_pk, 0);
+    if (!response_event) {
+        fprintf(stderr, "failed to create encrypted response event\n");
+        nostr_nip46_free_response(&resp);
+        nostr_nip46_free_request(&req);
+        nostr_nip46_signer_session_destroy(&signer);
+        nostr_cleanup();
+        return 1;
+    }
+
+    char* response_event_json = cJSON_Print(response_event);
+    if (response_event_json) {
+        printf("\nEncrypted response event (publish this to relays):\n%s\n", response_event_json);
+        free(response_event_json);
+    }
+
+    cJSON_Delete(response_event);
+    nostr_nip46_free_response(&resp);
+    nostr_nip46_free_request(&req);
+    nostr_nip46_signer_session_destroy(&signer);
+    nostr_cleanup();
+
+    return 0;
+}

examples/note_poster.c

@@ -0,0 +1,300 @@
+/*
+ * note_poster - minimal sign-in + kind-1 post test app
+ *
+ * Supports signer modes:
+ * - local (default): sign in with a local key (nsec or hex private key)
+ * - unix:<name>: use remote nsigner over AF_UNIX abstract socket
+ * - serial:<path>: use remote nsigner over USB CDC serial (e.g. /dev/ttyACM0)
+ * - tcp:<host>:<port>: use remote nsigner over TCP (auth envelope required by n_signer)
+ * - fds:<read_fd>:<write_fd>: use remote nsigner over existing framed fd pair (stdio/qrexec helper)
+ *
+ * Creates and signs a kind-1 note through nostr_signer_t,
+ * then publishes to wss://relay.laantungir.net
+ */
+
+#include "../nostr_core/nostr_core.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#define DEFAULT_RELAY "wss://relay.laantungir.net"
+
+static void publish_progress_callback(const char* relay_url,
+                                      const char* status,
+                                      const char* message,
+                                      int success_count,
+                                      int total_relays,
+                                      int completed_relays,
+                                      void* user_data) {
+    (void)user_data;
+
+    if (relay_url) {
+        printf("[%s] %s", relay_url, status ? status : "(unknown)");
+        if (message) {
+            printf(" - %s", message);
+        }
+        printf(" (%d/%d complete, %d success)\n", completed_relays, total_relays, success_count);
+    }
+}
+
+static int read_line(const char* prompt, char* out, size_t out_sz) {
+    size_t len;
+    if (!prompt || !out || out_sz == 0) {
+        return -1;
+    }
+
+    printf("%s", prompt);
+    if (!fgets(out, (int)out_sz, stdin)) {
+        return -1;
+    }
+
+    len = strlen(out);
+    if (len > 0 && out[len - 1] == '\n') {
+        out[len - 1] = '\0';
+    }
+
+    return 0;
+}
+
+static int parse_private_key_input(const char* input, unsigned char out_privkey[32]) {
+    if (!input || !out_privkey) {
+        return -1;
+    }
+
+    if (strncmp(input, "nsec1", 5) == 0) {
+        return nostr_decode_nsec(input, out_privkey);
+    }
+
+    if (strlen(input) == 64) {
+        return nostr_hex_to_bytes(input, out_privkey, 32);
+    }
+
+    return -1;
+}
+
+int main(int argc, char* argv[]) {
+    unsigned char private_key[32] = {0};
+    char key_input[256] = {0};
+    char note_content[2048] = {0};
+    nostr_signer_t* signer = NULL;
+    char pubkey_hex[65] = {0};
+    cJSON* note_event = NULL;
+    cJSON* id_item;
+    const char* relay_urls[] = {DEFAULT_RELAY};
+    int success_count = 0;
+    publish_result_t* results = NULL;
+    enum {
+        SIGNER_MODE_LOCAL = 0,
+        SIGNER_MODE_UNIX = 1,
+        SIGNER_MODE_SERIAL = 2,
+        SIGNER_MODE_TCP = 3,
+        SIGNER_MODE_FDS = 4
+    } signer_mode = SIGNER_MODE_LOCAL;
+    const char* unix_name = NULL;
+    const char* serial_path = NULL;
+    char tcp_host[256] = {0};
+    int tcp_port = 0;
+    int fds_read_fd = -1;
+    int fds_write_fd = -1;
+    int argi = 1;
+
+    if (argc >= 3 && strcmp(argv[1], "--signer") == 0) {
+        if (strncmp(argv[2], "unix:", 5) == 0 && argv[2][5] != '\0') {
+            signer_mode = SIGNER_MODE_UNIX;
+            unix_name = argv[2] + 5;
+        } else if (strncmp(argv[2], "serial:", 7) == 0 && argv[2][7] != '\0') {
+            signer_mode = SIGNER_MODE_SERIAL;
+            serial_path = argv[2] + 7;
+        } else if (strncmp(argv[2], "tcp:", 4) == 0 && argv[2][4] != '\0') {
+            const char* spec = argv[2] + 4;
+            const char* sep = strrchr(spec, ':');
+            char* endptr = NULL;
+            long parsed_port;
+            size_t host_len;
+
+            if (sep == NULL || sep == spec || sep[1] == '\0') {
+                fprintf(stderr, "Invalid tcp signer format. Use tcp:<host>:<port>\n");
+                return 1;
+            }
+
+            host_len = (size_t)(sep - spec);
+            if (host_len >= sizeof(tcp_host)) {
+                fprintf(stderr, "TCP host too long\n");
+                return 1;
+            }
+
+            memcpy(tcp_host, spec, host_len);
+            tcp_host[host_len] = '\0';
+
+            parsed_port = strtol(sep + 1, &endptr, 10);
+            if (endptr == NULL || *endptr != '\0' || parsed_port <= 0 || parsed_port > 65535) {
+                fprintf(stderr, "Invalid TCP port in --signer tcp:<host>:<port>\n");
+                return 1;
+            }
+
+            signer_mode = SIGNER_MODE_TCP;
+            tcp_port = (int)parsed_port;
+        } else if (strncmp(argv[2], "fds:", 4) == 0 && argv[2][4] != '\0') {
+            int parsed = -1;
+            parsed = sscanf(argv[2] + 4, "%d:%d", &fds_read_fd, &fds_write_fd);
+            if (parsed != 2 || fds_read_fd < 0 || fds_write_fd < 0) {
+                fprintf(stderr, "Invalid fds signer format. Use fds:<read_fd>:<write_fd>\n");
+                return 1;
+            }
+            signer_mode = SIGNER_MODE_FDS;
+        } else if (strcmp(argv[2], "local") == 0) {
+            signer_mode = SIGNER_MODE_LOCAL;
+        } else {
+            fprintf(stderr,
+                    "Invalid --signer value. Use --signer local, --signer unix:<name>, --signer serial:<path>, --signer tcp:<host>:<port>, or --signer fds:<read_fd>:<write_fd>\n");
+            return 1;
+        }
+        argi = 3;
+    }
+
+    if (signer_mode == SIGNER_MODE_LOCAL) {
+        if (argc > argi) {
+            strncpy(key_input, argv[argi], sizeof(key_input) - 1);
+            argi++;
+        } else if (read_line("Enter nsec or 64-char hex private key: ", key_input, sizeof(key_input)) != 0) {
+            fprintf(stderr, "Failed to read key input\n");
+            return 1;
+        }
+
+        fprintf(stderr, "WARNING: This is a TEST-KEY-ONLY tool. Do not use a real/production nsec. Keys are read into process memory in plaintext.\n");
+        if (parse_private_key_input(key_input, private_key) != 0) {
+            fprintf(stderr, "Invalid private key input (must be nsec1... or 64-char hex)\n");
+            return 1;
+        }
+    }
+
+    if (argc > argi) {
+        strncpy(note_content, argv[argi], sizeof(note_content) - 1);
+    } else if (read_line("Enter note content: ", note_content, sizeof(note_content)) != 0) {
+        fprintf(stderr, "Failed to read note content\n");
+        return 1;
+    }
+
+    if (nostr_init() != NOSTR_SUCCESS) {
+        fprintf(stderr, "Failed to initialize nostr library\n");
+        return 1;
+    }
+
+    if (signer_mode == SIGNER_MODE_UNIX) {
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+        signer = nostr_signer_nsigner_unix(unix_name, NULL, 15000);
+        if (!signer) {
+            fprintf(stderr, "Failed to initialize unix nsigner backend (%s)\n", unix_name);
+            nostr_cleanup();
+            return 1;
+        }
+#else
+        fprintf(stderr, "This build does not include nsigner client support\n");
+        nostr_cleanup();
+        return 1;
+#endif
+    } else if (signer_mode == SIGNER_MODE_SERIAL) {
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+        signer = nostr_signer_nsigner_serial(serial_path, NULL, 15000);
+        if (!signer) {
+            fprintf(stderr, "Failed to initialize serial nsigner backend (%s)\n", serial_path);
+            nostr_cleanup();
+            return 1;
+        }
+#else
+        fprintf(stderr, "This build does not include nsigner client support\n");
+        nostr_cleanup();
+        return 1;
+#endif
+    } else if (signer_mode == SIGNER_MODE_TCP) {
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+        signer = nostr_signer_nsigner_tcp(tcp_host, tcp_port, NULL, 15000);
+        if (!signer) {
+            fprintf(stderr, "Failed to initialize tcp nsigner backend (%s:%d)\n", tcp_host, tcp_port);
+            nostr_cleanup();
+            return 1;
+        }
+#else
+        fprintf(stderr, "This build does not include nsigner client support\n");
+        nostr_cleanup();
+        return 1;
+#endif
+    } else if (signer_mode == SIGNER_MODE_FDS) {
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+        signer = nostr_signer_nsigner_fds(fds_read_fd, fds_write_fd, NULL, 15000);
+        if (!signer) {
+            fprintf(stderr, "Failed to initialize fds nsigner backend (%d:%d)\n", fds_read_fd, fds_write_fd);
+            nostr_cleanup();
+            return 1;
+        }
+#else
+        fprintf(stderr, "This build does not include nsigner client support\n");
+        nostr_cleanup();
+        return 1;
+#endif
+    } else {
+        signer = nostr_signer_local(private_key);
+        if (!signer) {
+            fprintf(stderr, "Failed to initialize local signer\n");
+            nostr_cleanup();
+            return 1;
+        }
+    }
+
+    if (nostr_signer_get_public_key(signer, pubkey_hex) != NOSTR_SUCCESS) {
+        fprintf(stderr, "Failed to get signer pubkey\n");
+        nostr_signer_free(signer);
+        nostr_cleanup();
+        return 1;
+    }
+
+    printf("Signed in as pubkey: %s\n", pubkey_hex);
+
+    note_event = nostr_create_and_sign_event_with_signer(1, note_content, NULL, signer, time(NULL));
+    if (!note_event) {
+        fprintf(stderr, "Failed to create/sign note event\n");
+        nostr_signer_free(signer);
+        nostr_cleanup();
+        return 1;
+    }
+
+    id_item = cJSON_GetObjectItem(note_event, "id");
+    if (id_item && cJSON_IsString(id_item)) {
+        printf("Created event id: %s\n", cJSON_GetStringValue(id_item));
+    }
+
+    printf("Publishing to %s ...\n", DEFAULT_RELAY);
+    results = synchronous_publish_event_with_progress(
+        relay_urls,
+        1,
+        note_event,
+        &success_count,
+        12,
+        publish_progress_callback,
+        NULL,
+        0,
+        NULL
+    );
+
+    if (!results || success_count < 1 || results[0] != PUBLISH_SUCCESS) {
+        fprintf(stderr, "Publish failed (success_count=%d, result=%d)\n",
+                success_count,
+                results ? (int)results[0] : -999);
+        if (results) {
+            free(results);
+        }
+        cJSON_Delete(note_event);
+        nostr_signer_free(signer);
+        nostr_cleanup();
+        return 1;
+    }
+
+    printf("✅ Published successfully to %s\n", DEFAULT_RELAY);
+
+    free(results);
+    cJSON_Delete(note_event);
+    nostr_signer_free(signer);
+    nostr_cleanup();
+    return 0;
+}

examples/ots_tool.c

@@ -0,0 +1,644 @@
+/*
+ * OpenTimestamps Command-Line Tool
+ *
+ * A simple tool for timestamping files with OpenTimestamps.
+ *
+ * Usage:
+ *   ./ots_tool stamp              Interactive: type text, save to file, submit to OTS
+ *   ./ots_tool stamp <file>       Timestamp an existing file
+ *   ./ots_tool check <file.ots>   Check if a proof is complete
+ *   ./ots_tool verify <file> <file.ots>  Verify a proof against a file
+ *   ./ots_tool upgrade <file.ots> Upgrade a pending proof
+ *
+ * The "stamp" command:
+ *   1. If no file argument, prompts for text input and saves it to a .txt file
+ *   2. Computes the SHA-256 hash of the file
+ *   3. Submits the hash to an OpenTimestamps calendar
+ *   4. Saves the initial .ots proof to <file>.ots
+ *   5. Polls every 60 seconds to check if the proof is complete
+ *   6. When complete, saves the upgraded proof and verifies it
+ *
+ * Options:
+ *   --calendar <url>   Use a specific OTS calendar (default: https://alice.btc.calendar.opentimestamps.org)
+ *   --interval <sec>   Poll interval in seconds (default: 60)
+ *   --max-wait <min>   Maximum wait time in minutes (default: 120 = 2 hours)
+ */
+
+#define _POSIX_C_SOURCE 200809L
+
+#include "nostr_core/nostr_core.h"
+#include "nostr_core/nip003.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/stat.h>
+
+#define DEFAULT_CALENDAR "https://alice.btc.calendar.opentimestamps.org"
+#define DEFAULT_INTERVAL_SEC 60
+#define DEFAULT_MAX_WAIT_MIN 120
+
+/* Read an entire file into a malloc'd buffer. Returns NULL on error. */
+static unsigned char* read_file(const char* path, size_t* len_out) {
+    FILE* f = fopen(path, "rb");
+    if (!f) return NULL;
+
+    fseek(f, 0, SEEK_END);
+    long size = ftell(f);
+    fseek(f, 0, SEEK_SET);
+
+    if (size < 0) {
+        fclose(f);
+        return NULL;
+    }
+
+    unsigned char* buf = (unsigned char*)malloc(size + 1);
+    if (!buf) {
+        fclose(f);
+        return NULL;
+    }
+
+    size_t nread = fread(buf, 1, size, f);
+    fclose(f);
+
+    if (nread != (size_t)size) {
+        free(buf);
+        return NULL;
+    }
+
+    buf[size] = '\0';
+    *len_out = (size_t)size;
+    return buf;
+}
+
+/* Write data to a file. Returns 0 on success, -1 on error. */
+static int write_file(const char* path, const unsigned char* data, size_t len) {
+    FILE* f = fopen(path, "wb");
+    if (!f) return -1;
+
+    size_t nwritten = fwrite(data, 1, len, f);
+    fclose(f);
+
+    return (nwritten == len) ? 0 : -1;
+}
+
+/* Compute SHA-256 of a file and return as hex string (64 chars + null). */
+static int compute_file_sha256_hex(const char* path, char* hex_out) {
+    size_t file_len = 0;
+    unsigned char* file_data = read_file(path, &file_len);
+    if (!file_data) return -1;
+
+    unsigned char digest[32];
+    int rc = nostr_sha256(file_data, file_len, digest);
+    free(file_data);
+
+    if (rc != NOSTR_SUCCESS) return -1;
+
+    nostr_bytes_to_hex(digest, 32, hex_out);
+    return 0;
+}
+
+/* Convert base64 string to binary file and save. */
+static int save_base64_to_file(const char* path, const char* b64) {
+    if (!b64) return -1;
+
+    size_t b64_len = strlen(b64);
+    size_t max_decoded = (b64_len / 4) * 3 + 3;
+    unsigned char* data = (unsigned char*)malloc(max_decoded);
+    if (!data) return -1;
+
+    size_t data_len = base64_decode(b64, data);
+    if (data_len == 0) {
+        free(data);
+        return -1;
+    }
+
+    int rc = write_file(path, data, data_len);
+    free(data);
+    return rc;
+}
+
+/* Read a binary file and convert to base64 string. Caller must free. */
+static char* read_file_as_base64(const char* path) {
+    size_t file_len = 0;
+    unsigned char* file_data = read_file(path, &file_len);
+    if (!file_data) return NULL;
+
+    size_t b64_size = ((file_len + 2) / 3) * 4 + 1;
+    char* b64 = (char*)malloc(b64_size);
+    if (!b64) {
+        free(file_data);
+        return NULL;
+    }
+
+    base64_encode(file_data, file_len, b64, b64_size);
+    free(file_data);
+    return b64;
+}
+
+static void print_usage(const char* prog) {
+    printf("OpenTimestamps Command-Line Tool\n");
+    printf("\n");
+    printf("Usage:\n");
+    printf("  %s stamp                  Interactive: type text, save, submit to OTS\n", prog);
+    printf("  %s stamp <file>           Timestamp an existing file\n", prog);
+    printf("  %s check <file.ots>       Check if a proof is complete\n", prog);
+    printf("  %s verify <file> <file.ots>  Verify a proof against a file\n", prog);
+    printf("  %s upgrade <file.ots> [file]  Upgrade a pending proof (optional: original file)\n", prog);
+    printf("\n");
+    printf("Options:\n");
+    printf("  --calendar <url>   OTS calendar URL (default: %s)\n", DEFAULT_CALENDAR);
+    printf("  --interval <sec>   Poll interval in seconds (default: %d)\n", DEFAULT_INTERVAL_SEC);
+    printf("  --max-wait <min>   Max wait time in minutes (default: %d)\n", DEFAULT_MAX_WAIT_MIN);
+    printf("\n");
+    printf("Examples:\n");
+    printf("  %s stamp                          # Type text, timestamp it\n", prog);
+    printf("  %s stamp mydocument.txt           # Timestamp a file\n", prog);
+    printf("  %s check mydocument.txt.ots       # Check proof status\n", prog);
+    printf("  %s verify mydocument.txt mydocument.txt.ots  # Verify proof\n", prog);
+}
+
+static int do_stamp(const char* file_path, const char* calendar_url,
+                    int interval_sec, int max_wait_min) {
+    char auto_file[256] = {0};
+    const char* target_file = file_path;
+
+    /* If no file specified, prompt for text input */
+    if (!target_file) {
+        printf("📝 Enter text to timestamp (press Enter twice to finish):\n\n");
+
+        /* Read multi-line input until empty line */
+        char* content = NULL;
+        size_t content_cap = 0;
+        size_t content_len = 0;
+        char line[1024];
+        int empty_count = 0;
+
+        while (fgets(line, sizeof(line), stdin)) {
+            if (line[0] == '\n') {
+                empty_count++;
+                if (empty_count >= 1 && content_len > 0) {
+                    break;
+                }
+            } else {
+                empty_count = 0;
+            }
+
+            size_t line_len = strlen(line);
+            if (content_len + line_len + 1 > content_cap) {
+                content_cap = (content_len + line_len + 1) * 2;
+                char* new_content = (char*)realloc(content, content_cap);
+                if (!new_content) {
+                    free(content);
+                    printf("❌ Out of memory\n");
+                    return 1;
+                }
+                content = new_content;
+            }
+            memcpy(content + content_len, line, line_len);
+            content_len += line_len;
+            content[content_len] = '\0';
+        }
+
+        if (!content || content_len == 0) {
+            printf("❌ No text entered.\n");
+            free(content);
+            return 1;
+        }
+
+        /* Generate a filename based on timestamp */
+        time_t now = time(NULL);
+        struct tm* tm_info = localtime(&now);
+        strftime(auto_file, sizeof(auto_file), "timestamped_%Y%m%d_%H%M%S.txt", tm_info);
+
+        /* Save the text to a file */
+        if (write_file(auto_file, (const unsigned char*)content, content_len) != 0) {
+            printf("❌ Failed to save text to file: %s\n", auto_file);
+            free(content);
+            return 1;
+        }
+
+        printf("\n💾 Saved text to: %s (%zu bytes)\n", auto_file, content_len);
+        free(content);
+        target_file = auto_file;
+    }
+
+    /* Compute SHA-256 of the file */
+    char digest_hex[65];
+    if (compute_file_sha256_hex(target_file, digest_hex) != 0) {
+        printf("❌ Failed to compute SHA-256 of file: %s\n", target_file);
+        return 1;
+    }
+
+    printf("🔐 SHA-256: %s\n", digest_hex);
+
+    /* Submit to multiple OTS calendars for redundancy */
+    const char* default_calendars[] = {
+        "https://alice.btc.calendar.opentimestamps.org",
+        "https://bob.btc.calendar.opentimestamps.org",
+        "https://finney.calendar.eternitywall.com",
+        "https://btc.calendar.catallaxy.com",
+    };
+    int num_calendars = 4;
+
+    /* If a specific calendar was specified, use only that one */
+    const char** calendars_to_use;
+    int num_to_use;
+    if (strcmp(calendar_url, DEFAULT_CALENDAR) != 0) {
+        calendars_to_use = &calendar_url;
+        num_to_use = 1;
+    } else {
+        calendars_to_use = default_calendars;
+        num_to_use = num_calendars;
+    }
+
+    printf("\n📤 Submitting to %d OpenTimestamps calendar(s)...\n", num_to_use);
+
+    /* Submit to all calendars and create a combined DetachedTimestampFile */
+    char* ots_b64 = nostr_nip03_stamp_with_multiple_calendars(
+        digest_hex, calendars_to_use, num_to_use, 30);
+    if (!ots_b64) {
+        printf("❌ Failed to submit to any calendar.\n");
+        printf("   Check your internet connection and try again.\n");
+        return 1;
+    }
+
+    /* Save the .ots proof */
+    char ots_path[512];
+    snprintf(ots_path, sizeof(ots_path), "%s.ots", target_file);
+
+    if (save_base64_to_file(ots_path, ots_b64) != 0) {
+        printf("❌ Failed to save .ots proof to: %s\n", ots_path);
+        free(ots_b64);
+        return 1;
+    }
+
+    printf("✅ Proof saved to: %s\n", ots_path);
+
+    /* Show attestation info - list all pending calendars */
+    char** pending_uris = NULL;
+    int pending_count = nostr_nip03_get_pending_uris(ots_b64, &pending_uris, 16);
+    if (pending_count > 0) {
+        printf("   Pending at %d calendar(s):\n", pending_count);
+        for (int i = 0; i < pending_count; i++) {
+            printf("     • %s\n", pending_uris[i]);
+            free(pending_uris[i]);
+        }
+        free(pending_uris);
+    }
+
+    /* Check if already complete (unlikely but possible) */
+    int complete = nostr_nip03_is_proof_complete(ots_b64);
+    if (complete == 1) {
+        printf("\n🎉 Proof is already complete!\n");
+        free(ots_b64);
+        return 0;
+    }
+
+    /* Poll for completion */
+    int max_attempts = (max_wait_min * 60) / interval_sec;
+    printf("\n⏳ Waiting for Bitcoin attestation...\n");
+    printf("   Polling every %d seconds (max %d minutes)\n", interval_sec, max_wait_min);
+    printf("   Press Ctrl+C to stop. The .ots file can be checked later with 'check'.\n\n");
+
+    int attempts = 0;
+    while (!complete && attempts < max_attempts) {
+        attempts++;
+
+        time_t now = time(NULL);
+        char time_str[26];
+        ctime_r(&now, time_str);
+        time_str[24] = '\0';
+
+        printf("[%s] Attempt %d/%d: %s\n", time_str, attempts, max_attempts,
+               complete ? "✅ COMPLETE" : "⏳ PENDING");
+        fflush(stdout);
+
+        if (complete) break;
+
+        sleep(interval_sec);
+
+        /* Try to upgrade the proof by walking the tree and fetching upgraded sub-proofs */
+        char* upgraded = nostr_nip03_upgrade_proof_tree(ots_b64, 30);
+        if (upgraded) {
+            free(ots_b64);
+            ots_b64 = upgraded;
+
+            /* Save the upgraded proof */
+            save_base64_to_file(ots_path, ots_b64);
+
+            /* Check if now complete */
+            complete = nostr_nip03_is_proof_complete(ots_b64);
+        }
+    }
+
+    if (complete) {
+        printf("\n🎉 SUCCESS! Proof is complete with a Bitcoin attestation!\n");
+
+        /* Save the final proof */
+        save_base64_to_file(ots_path, ots_b64);
+        printf("   Final proof saved to: %s\n", ots_path);
+
+        /* Show attestation details */
+        int has_bitcoin = 0;
+        uint64_t btc_height = 0;
+        if (nostr_nip03_get_attestation_info(ots_b64, &has_bitcoin, NULL, NULL,
+                                             &btc_height, NULL, NULL) == 0) {
+            if (has_bitcoin) {
+                printf("   Bitcoin block height: %llu\n", (unsigned long long)btc_height);
+            }
+        }
+
+        /* Verify the proof */
+        uint64_t verify_height = 0;
+        int verify_rc = nostr_nip03_verify_proof(ots_b64, digest_hex, &verify_height, NULL);
+        if (verify_rc == 0) {
+            printf("   ✅ Verified: file digest matches, Bitcoin height=%llu\n",
+                   (unsigned long long)verify_height);
+        } else {
+            printf("   ⚠️ Verification returned: %d\n", verify_rc);
+        }
+    } else {
+        printf("\n⏳ Proof is still pending after %d minutes.\n", max_wait_min);
+        printf("   The .ots file has been saved: %s\n", ots_path);
+        printf("   Check again later with: ./ots_tool check %s\n", ots_path);
+        printf("   Or upgrade with: ./ots_tool upgrade %s\n", ots_path);
+    }
+
+    free(ots_b64);
+    return complete ? 0 : 2;
+}
+
+static int do_check(const char* ots_path) {
+    printf("🔎 Checking proof: %s\n\n", ots_path);
+
+    char* ots_b64 = read_file_as_base64(ots_path);
+    if (!ots_b64) {
+        printf("❌ Failed to read .ots file: %s\n", ots_path);
+        return 1;
+    }
+
+    int complete = nostr_nip03_is_proof_complete(ots_b64);
+
+    if (complete == 1) {
+        printf("✅ Proof is COMPLETE (has Bitcoin/Litecoin attestation)\n");
+    } else if (complete == 0) {
+        printf("⏳ Proof is PENDING (no Bitcoin attestation yet)\n");
+    } else {
+        printf("❌ Failed to parse proof (invalid OTS file?)\n");
+        free(ots_b64);
+        return 1;
+    }
+
+    /* Show detailed attestation info */
+    int has_bitcoin = 0, has_litecoin = 0, has_pending = 0;
+    uint64_t btc_height = 0, ltc_height = 0;
+
+    if (nostr_nip03_get_attestation_info(ots_b64, &has_bitcoin, &has_litecoin, &has_pending,
+                                         &btc_height, &ltc_height, NULL) == 0) {
+        if (has_bitcoin) {
+            printf("   ✅ Bitcoin attestation: block height %llu\n", (unsigned long long)btc_height);
+        }
+        if (has_litecoin) {
+            printf("   ✅ Litecoin attestation: block height %llu\n", (unsigned long long)ltc_height);
+        }
+    }
+
+    /* Show all pending calendar URIs */
+    if (has_pending) {
+        char** pending_uris = NULL;
+        int pending_count = nostr_nip03_get_pending_uris(ots_b64, &pending_uris, 16);
+        if (pending_count > 0) {
+            printf("   ⏳ Pending at %d calendar(s):\n", pending_count);
+            for (int i = 0; i < pending_count; i++) {
+                printf("     • %s\n", pending_uris[i]);
+                free(pending_uris[i]);
+            }
+            free(pending_uris);
+        }
+    }
+
+    free(ots_b64);
+    return 0;
+}
+
+static int do_verify(const char* file_path, const char* ots_path) {
+    printf("🔍 Verifying proof...\n");
+    printf("   File: %s\n", file_path);
+    printf("   Proof: %s\n\n", ots_path);
+
+    /* Compute SHA-256 of the file */
+    char digest_hex[65];
+    if (compute_file_sha256_hex(file_path, digest_hex) != 0) {
+        printf("❌ Failed to compute SHA-256 of file: %s\n", file_path);
+        return 1;
+    }
+    printf("   File SHA-256: %s\n", digest_hex);
+
+    /* Read the .ots file */
+    char* ots_b64 = read_file_as_base64(ots_path);
+    if (!ots_b64) {
+        printf("❌ Failed to read .ots file: %s\n", ots_path);
+        return 1;
+    }
+
+    /* Verify the proof */
+    uint64_t block_height = 0;
+    time_t block_time = 0;
+    int rc = nostr_nip03_verify_proof(ots_b64, digest_hex, &block_height, &block_time);
+
+    switch (rc) {
+        case 0:
+            printf("\n✅ Proof VERIFIED!\n");
+            printf("   Bitcoin block height: %llu\n", (unsigned long long)block_height);
+            printf("   The file's hash is committed in the Bitcoin blockchain.\n");
+            free(ots_b64);
+            return 0;
+
+        case 1:
+            printf("\n⏳ Proof is valid but still PENDING (no Bitcoin attestation yet).\n");
+            printf("   The file digest matches the proof.\n");
+            printf("   Wait for the calendar to commit to the blockchain, then run:\n");
+            printf("     ./ots_tool upgrade %s\n", ots_path);
+            free(ots_b64);
+            return 1;
+
+        case -1:
+            printf("\n❌ Failed to parse OTS proof. The .ots file may be corrupted.\n");
+            free(ots_b64);
+            return 1;
+
+        case -2:
+            printf("\n❌ DIGEST MISMATCH! The proof does not match this file.\n");
+            printf("   The file may have been modified after timestamping.\n");
+            free(ots_b64);
+            return 1;
+
+        default:
+            printf("\n❌ Unknown error: %d\n", rc);
+            free(ots_b64);
+            return 1;
+    }
+}
+
+static int do_upgrade(const char* ots_path, const char* file_path,
+                       const char* calendar_url) {
+    printf("⬆️ Upgrading proof: %s\n\n", ots_path);
+
+    char* ots_b64 = read_file_as_base64(ots_path);
+    if (!ots_b64) {
+        printf("❌ Failed to read .ots file: %s\n", ots_path);
+        return 1;
+    }
+
+    /* Check current status */
+    int was_complete = nostr_nip03_is_proof_complete(ots_b64);
+    if (was_complete == 1) {
+        printf("✅ Proof is already complete! No upgrade needed.\n");
+        free(ots_b64);
+        return 0;
+    }
+
+    (void)calendar_url; /* upgrade now uses pending-attestation URIs from proof */
+    (void)file_path;
+
+    printf("📤 Checking pending attestations and fetching upgrades...\n");
+
+    char* upgraded = NULL;
+    /* Use the tree-walking upgrade which correctly queries commitment hashes */
+    upgraded = nostr_nip03_upgrade_proof_tree(ots_b64, 30);
+
+    if (!upgraded) {
+        printf("⏳ No upgrade available yet. The proof is still pending.\n");
+        printf("   Bitcoin attestations typically take 1-12 hours.\n");
+        if (!file_path) {
+            printf("   Tip: provide the original file path to enable digest-based upgrade:\n");
+            printf("     ./ots_tool upgrade %s <original-file>\n", ots_path);
+        }
+        free(ots_b64);
+        return 1;
+    }
+
+    /* Save the upgraded proof */
+    if (save_base64_to_file(ots_path, upgraded) != 0) {
+        printf("❌ Failed to save upgraded proof.\n");
+        free(ots_b64);
+        free(upgraded);
+        return 1;
+    }
+
+    /* Check if now complete */
+    int complete = nostr_nip03_is_proof_complete(upgraded);
+    if (complete == 1) {
+        printf("✅ Upgrade successful! Proof is now COMPLETE with a Bitcoin attestation.\n");
+
+        int has_bitcoin = 0;
+        uint64_t btc_height = 0;
+        if (nostr_nip03_get_attestation_info(upgraded, &has_bitcoin, NULL, NULL,
+                                             &btc_height, NULL, NULL) == 0) {
+            if (has_bitcoin) {
+                printf("   Bitcoin block height: %llu\n", (unsigned long long)btc_height);
+            }
+        }
+    } else {
+        printf("⏳ Upgrade received but proof is still pending.\n");
+        printf("   The upgraded proof has been saved. Try again later.\n");
+    }
+
+    printf("   Updated proof saved to: %s\n", ots_path);
+
+    free(ots_b64);
+    free(upgraded);
+    return 0;
+}
+
+int main(int argc, char* argv[]) {
+    if (nostr_init() != NOSTR_SUCCESS) {
+        fprintf(stderr, "Failed to initialize NOSTR library\n");
+        return 1;
+    }
+
+    const char* calendar_url = DEFAULT_CALENDAR;
+    int interval_sec = DEFAULT_INTERVAL_SEC;
+    int max_wait_min = DEFAULT_MAX_WAIT_MIN;
+
+    enum { MODE_NONE, MODE_STAMP, MODE_CHECK, MODE_VERIFY, MODE_UPGRADE } mode = MODE_NONE;
+    const char* arg1 = NULL;
+    const char* arg2 = NULL;
+
+    /* Parse arguments */
+    for (int i = 1; i < argc; i++) {
+        if (strcmp(argv[i], "--help") == 0 || strcmp(argv[i], "-h") == 0) {
+            print_usage(argv[0]);
+            nostr_cleanup();
+            return 0;
+        } else if (strcmp(argv[i], "--calendar") == 0 && i + 1 < argc) {
+            calendar_url = argv[++i];
+        } else if (strcmp(argv[i], "--interval") == 0 && i + 1 < argc) {
+            interval_sec = atoi(argv[++i]);
+        } else if (strcmp(argv[i], "--max-wait") == 0 && i + 1 < argc) {
+            max_wait_min = atoi(argv[++i]);
+        } else if (strcmp(argv[i], "stamp") == 0) {
+            mode = MODE_STAMP;
+        } else if (strcmp(argv[i], "check") == 0) {
+            mode = MODE_CHECK;
+        } else if (strcmp(argv[i], "verify") == 0) {
+            mode = MODE_VERIFY;
+        } else if (strcmp(argv[i], "upgrade") == 0) {
+            mode = MODE_UPGRADE;
+        } else if (argv[i][0] != '-') {
+            if (!arg1) {
+                arg1 = argv[i];
+            } else if (!arg2) {
+                arg2 = argv[i];
+            }
+        }
+    }
+
+    int rc = 0;
+
+    switch (mode) {
+        case MODE_STAMP:
+            rc = do_stamp(arg1, calendar_url, interval_sec, max_wait_min);
+            break;
+
+        case MODE_CHECK:
+            if (!arg1) {
+                printf("❌ Missing .ots file path\n");
+                print_usage(argv[0]);
+                rc = 1;
+            } else {
+                rc = do_check(arg1);
+            }
+            break;
+
+        case MODE_VERIFY:
+            if (!arg1 || !arg2) {
+                printf("❌ Missing file or .ots path\n");
+                print_usage(argv[0]);
+                rc = 1;
+            } else {
+                rc = do_verify(arg1, arg2);
+            }
+            break;
+
+        case MODE_UPGRADE:
+            if (!arg1) {
+                printf("❌ Missing .ots file path\n");
+                print_usage(argv[0]);
+                rc = 1;
+            } else {
+                rc = do_upgrade(arg1, arg2, calendar_url);
+            }
+            break;
+
+        default:
+            print_usage(argv[0]);
+            rc = 1;
+            break;
+    }
+
+    nostr_cleanup();
+    return rc;
+}

examples/relay_pool.c

@@ -0,0 +1,889 @@
+/*
+ * Interactive Relay Pool Test Program
+ *
+ * Interactive command-line interface for testing nostr_relay_pool functionality.
+ * All output is logged to pool.log while the menu runs in the terminal.
+ *
+ * Usage: ./pool_test
+ */
+
+#define _POSIX_C_SOURCE 200809L
+#define _DEFAULT_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <time.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include "../nostr_core/nostr_core.h"
+#include "../cjson/cJSON.h"
+
+// Global variables
+volatile sig_atomic_t running = 1;
+nostr_relay_pool_t* pool = NULL;
+nostr_pool_subscription_t** subscriptions = NULL;
+int subscription_count = 0;
+int subscription_capacity = 0;
+pthread_t poll_thread;
+int log_fd = -1;
+
+// Signal handler for clean shutdown
+void signal_handler(int signum) {
+    (void)signum;
+    running = 0;
+}
+
+// Event callback - called when an event is received
+void on_event(cJSON* event, const char* relay_url, void* user_data) {
+    (void)user_data;
+
+    // Extract basic event information
+    cJSON* id = cJSON_GetObjectItem(event, "id");
+    cJSON* pubkey = cJSON_GetObjectItem(event, "pubkey");
+    cJSON* created_at = cJSON_GetObjectItem(event, "created_at");
+    cJSON* kind = cJSON_GetObjectItem(event, "kind");
+    cJSON* content = cJSON_GetObjectItem(event, "content");
+
+    time_t now = time(NULL);
+    char timestamp[26];
+    ctime_r(&now, timestamp);
+    timestamp[24] = '\0'; // Remove newline
+
+    dprintf(log_fd, "[%s] 📨 EVENT from %s\n", timestamp, relay_url);
+    dprintf(log_fd, "├── ID: %.12s...\n", id && cJSON_IsString(id) ? cJSON_GetStringValue(id) : "unknown");
+    dprintf(log_fd, "├── Pubkey: %.12s...\n", pubkey && cJSON_IsString(pubkey) ? cJSON_GetStringValue(pubkey) : "unknown");
+    dprintf(log_fd, "├── Kind: %d\n", kind && cJSON_IsNumber(kind) ? (int)cJSON_GetNumberValue(kind) : -1);
+    dprintf(log_fd, "├── Created: %lld\n", created_at && cJSON_IsNumber(created_at) ? (long long)cJSON_GetNumberValue(created_at) : 0);
+
+    // Truncate content if too long
+    if (content && cJSON_IsString(content)) {
+        const char* content_str = cJSON_GetStringValue(content);
+        size_t content_len = strlen(content_str);
+        if (content_len > 100) {
+            dprintf(log_fd, "└── Content: %.97s...\n", content_str);
+        } else {
+            dprintf(log_fd, "└── Content: %s\n", content_str);
+        }
+    } else {
+        dprintf(log_fd, "└── Content: (empty)\n");
+    }
+    dprintf(log_fd, "\n");
+}
+
+// EOSE callback - called when End of Stored Events is received
+void on_eose(cJSON** events, int event_count, void* user_data) {
+    (void)user_data;
+    time_t now = time(NULL);
+    char timestamp[26];
+    ctime_r(&now, timestamp);
+    timestamp[24] = '\0';
+    dprintf(log_fd, "[%s] 📋 EOSE received - %d events collected\n", timestamp, event_count);
+
+    // Log collected events if any
+    for (int i = 0; i < event_count; i++) {
+        cJSON* id = cJSON_GetObjectItem(events[i], "id");
+        if (id && cJSON_IsString(id)) {
+            dprintf(log_fd, "  Event %d: %.12s...\n", i + 1, cJSON_GetStringValue(id));
+        }
+    }
+    dprintf(log_fd, "\n");
+}
+
+// Background polling thread
+void* poll_thread_func(void* arg) {
+    (void)arg;
+
+    while (running) {
+        if (pool) {
+            nostr_relay_pool_poll(pool, 100);
+        }
+        struct timespec ts = {0, 10000000}; // 10ms
+        nanosleep(&ts, NULL);
+    }
+
+    return NULL;
+}
+
+// Print menu
+void print_menu() {
+    printf("\n=== NOSTR Relay Pool Test Menu ===\n");
+    printf("1. Start Pool (ws://localhost:7555)\n");
+    printf("2. Stop Pool\n");
+    printf("3. Add relay to pool\n");
+    printf("4. Remove relay from pool\n");
+    printf("5. Add subscription\n");
+    printf("6. Remove subscription\n");
+    printf("7. Show pool status\n");
+    printf("8. Test reconnection (simulate disconnect)\n");
+    printf("9. Publish Event\n");
+    printf("0. Exit\n");
+    printf("Choice: ");
+}
+
+// Get user input with default
+char* get_input(const char* prompt, const char* default_value) {
+    static char buffer[1024];
+    printf("%s", prompt);
+    if (default_value) {
+        printf(" [%s]", default_value);
+    }
+    printf(": ");
+
+    if (!fgets(buffer, sizeof(buffer), stdin)) {
+        return NULL;
+    }
+
+    // Remove newline
+    size_t len = strlen(buffer);
+    if (len > 0 && buffer[len-1] == '\n') {
+        buffer[len-1] = '\0';
+    }
+
+    // Return default if empty
+    if (strlen(buffer) == 0 && default_value) {
+        return strdup(default_value);
+    }
+
+    return strdup(buffer);
+}
+
+// Parse comma-separated list into cJSON array
+cJSON* parse_comma_list(const char* input, int is_number) {
+    if (!input || strlen(input) == 0) {
+        return NULL;
+    }
+
+    cJSON* array = cJSON_CreateArray();
+    if (!array) return NULL;
+
+    char* input_copy = strdup(input);
+    char* token = strtok(input_copy, ",");
+
+    while (token) {
+        // Trim whitespace
+        while (*token == ' ') token++;
+        char* end = token + strlen(token) - 1;
+        while (end > token && *end == ' ') *end-- = '\0';
+
+        if (is_number) {
+            int num = atoi(token);
+            cJSON_AddItemToArray(array, cJSON_CreateNumber(num));
+        } else {
+            cJSON_AddItemToArray(array, cJSON_CreateString(token));
+        }
+
+        token = strtok(NULL, ",");
+    }
+
+    free(input_copy);
+    return array;
+}
+
+// Add subscription interactively
+void add_subscription() {
+    if (!pool) {
+        printf("❌ Pool not started\n");
+        return;
+    }
+
+    printf("\n--- Add Subscription ---\n");
+    printf("Enter filter values (press Enter for no value):\n");
+
+    cJSON* filter = cJSON_CreateObject();
+
+    // ids
+    char* ids_input = get_input("ids (comma-separated event ids)", NULL);
+    if (ids_input && strlen(ids_input) > 0) {
+        cJSON* ids = parse_comma_list(ids_input, 0);
+        if (ids) cJSON_AddItemToObject(filter, "ids", ids);
+    }
+    free(ids_input);
+
+    // authors
+    char* authors_input = get_input("authors (comma-separated pubkeys)", NULL);
+    if (authors_input && strlen(authors_input) > 0) {
+        cJSON* authors = parse_comma_list(authors_input, 0);
+        if (authors) cJSON_AddItemToObject(filter, "authors", authors);
+    }
+    free(authors_input);
+
+    // kinds
+    char* kinds_input = get_input("kinds (comma-separated numbers)", NULL);
+    if (kinds_input && strlen(kinds_input) > 0) {
+        cJSON* kinds = parse_comma_list(kinds_input, 1);
+        if (kinds) cJSON_AddItemToObject(filter, "kinds", kinds);
+    }
+    free(kinds_input);
+
+    // #e tag
+    char* e_input = get_input("#e (comma-separated event ids)", NULL);
+    if (e_input && strlen(e_input) > 0) {
+        cJSON* e_array = parse_comma_list(e_input, 0);
+        if (e_array) cJSON_AddItemToObject(filter, "#e", e_array);
+    }
+    free(e_input);
+
+    // #p tag
+    char* p_input = get_input("#p (comma-separated pubkeys)", NULL);
+    if (p_input && strlen(p_input) > 0) {
+        cJSON* p_array = parse_comma_list(p_input, 0);
+        if (p_array) cJSON_AddItemToObject(filter, "#p", p_array);
+    }
+    free(p_input);
+
+    // since
+    char* since_input = get_input("since (unix timestamp or 'n' for now)", NULL);
+    if (since_input && strlen(since_input) > 0) {
+        if (strcmp(since_input, "n") == 0) {
+            // Use current timestamp
+            time_t now = time(NULL);
+            cJSON_AddItemToObject(filter, "since", cJSON_CreateNumber((int)now));
+            printf("Using current timestamp: %ld\n", now);
+        } else {
+            int since = atoi(since_input);
+            if (since > 0) cJSON_AddItemToObject(filter, "since", cJSON_CreateNumber(since));
+        }
+    }
+    free(since_input);
+
+    // until
+    char* until_input = get_input("until (unix timestamp)", NULL);
+    if (until_input && strlen(until_input) > 0) {
+        int until = atoi(until_input);
+        if (until > 0) cJSON_AddItemToObject(filter, "until", cJSON_CreateNumber(until));
+    }
+    free(until_input);
+
+    // limit
+    char* limit_input = get_input("limit (max events)", "10");
+    if (limit_input && strlen(limit_input) > 0) {
+        int limit = atoi(limit_input);
+        if (limit > 0) cJSON_AddItemToObject(filter, "limit", cJSON_CreateNumber(limit));
+    }
+    free(limit_input);
+
+    // Get relay URLs from pool
+    char** relay_urls = NULL;
+    nostr_pool_relay_status_t* statuses = NULL;
+    int relay_count = nostr_relay_pool_list_relays(pool, &relay_urls, &statuses);
+
+    if (relay_count <= 0) {
+        printf("❌ No relays in pool\n");
+        cJSON_Delete(filter);
+        return;
+    }
+
+    // Ask about close_on_eose behavior
+    char* close_input = get_input("Close subscription on EOSE? (y/n)", "n");
+    int close_on_eose = (close_input && strcmp(close_input, "y") == 0) ? 1 : 0;
+    free(close_input);
+
+    // Create subscription with new parameters
+    nostr_pool_subscription_t* sub = nostr_relay_pool_subscribe(
+        pool,
+        (const char**)relay_urls,
+        relay_count,
+        filter,
+        on_event,
+        on_eose,
+        NULL,
+        close_on_eose,
+        1,  // enable_deduplication
+        NOSTR_POOL_EOSE_FULL_SET,  // result_mode
+        30,  // relay_timeout_seconds
+        60   // eose_timeout_seconds
+    );
+
+    // Free relay URLs
+    for (int i = 0; i < relay_count; i++) {
+        free(relay_urls[i]);
+    }
+    free(relay_urls);
+    free(statuses);
+
+    if (!sub) {
+        printf("❌ Failed to create subscription\n");
+        cJSON_Delete(filter);
+        return;
+    }
+
+    // Store subscription
+    if (subscription_count >= subscription_capacity) {
+        subscription_capacity = subscription_capacity == 0 ? 10 : subscription_capacity * 2;
+        subscriptions = realloc(subscriptions, subscription_capacity * sizeof(nostr_pool_subscription_t*));
+    }
+    subscriptions[subscription_count++] = sub;
+
+    printf("✅ Subscription created (ID: %d)\n", subscription_count);
+
+    // Log the filter
+    char* filter_json = cJSON_Print(filter);
+    time_t now = time(NULL);
+    char timestamp[26];
+    ctime_r(&now, timestamp);
+    timestamp[24] = '\0';
+    dprintf(log_fd, "[%s] 🔍 New subscription created (ID: %d)\n", timestamp, subscription_count);
+    dprintf(log_fd, "Filter: %s\n\n", filter_json);
+    free(filter_json);
+}
+
+// Remove subscription
+void remove_subscription() {
+    if (subscription_count == 0) {
+        printf("❌ No subscriptions to remove\n");
+        return;
+    }
+
+    printf("\n--- Remove Subscription ---\n");
+    printf("Available subscriptions:\n");
+    for (int i = 0; i < subscription_count; i++) {
+        printf("%d. Subscription %d\n", i + 1, i + 1);
+    }
+
+    char* choice_input = get_input("Enter subscription number to remove", NULL);
+    if (!choice_input || strlen(choice_input) == 0) {
+        free(choice_input);
+        return;
+    }
+
+    int choice = atoi(choice_input) - 1;
+    free(choice_input);
+
+    if (choice < 0 || choice >= subscription_count) {
+        printf("❌ Invalid subscription number\n");
+        return;
+    }
+
+    nostr_pool_subscription_close(subscriptions[choice]);
+
+    // Shift remaining subscriptions
+    for (int i = choice; i < subscription_count - 1; i++) {
+        subscriptions[i] = subscriptions[i + 1];
+    }
+    subscription_count--;
+
+    printf("✅ Subscription removed\n");
+
+    time_t now = time(NULL);
+    char timestamp[26];
+    ctime_r(&now, timestamp);
+    timestamp[24] = '\0';
+    dprintf(log_fd, "[%s] 🗑️ Subscription removed (was ID: %d)\n\n", timestamp, choice + 1);
+}
+
+// Show pool status
+void show_pool_status() {
+    if (!pool) {
+        printf("❌ Pool not started\n");
+        return;
+    }
+
+    // Give polling thread time to establish connections
+    printf("⏳ Waiting for connections to establish...\n");
+    sleep(3);
+
+    char** relay_urls = NULL;
+    nostr_pool_relay_status_t* statuses = NULL;
+    int relay_count = nostr_relay_pool_list_relays(pool, &relay_urls, &statuses);
+
+    printf("\n📊 POOL STATUS\n");
+    printf("Relays: %d\n", relay_count);
+    printf("Subscriptions: %d\n", subscription_count);
+
+    if (relay_count > 0) {
+        printf("\nRelay Details:\n");
+        for (int i = 0; i < relay_count; i++) {
+            const char* status_str;
+            switch (statuses[i]) {
+                case NOSTR_POOL_RELAY_CONNECTED: status_str = "🟢 CONNECTED"; break;
+                case NOSTR_POOL_RELAY_CONNECTING: status_str = "🟡 CONNECTING"; break;
+                case NOSTR_POOL_RELAY_DISCONNECTED: status_str = "⚪ DISCONNECTED"; break;
+                case NOSTR_POOL_RELAY_ERROR: status_str = "🔴 ERROR"; break;
+                default: status_str = "❓ UNKNOWN"; break;
+            }
+
+            printf("├── %s: %s\n", relay_urls[i], status_str);
+
+            // Show connection and publish error details
+            const char* conn_error = nostr_relay_pool_get_relay_last_connection_error(pool, relay_urls[i]);
+            const char* pub_error = nostr_relay_pool_get_relay_last_publish_error(pool, relay_urls[i]);
+            
+            if (conn_error) {
+                printf("│   ├── Connection error: %s\n", conn_error);
+            }
+            if (pub_error) {
+                printf("│   ├── Last publish error: %s\n", pub_error);
+            }
+
+            const nostr_relay_stats_t* stats = nostr_relay_pool_get_relay_stats(pool, relay_urls[i]);
+            if (stats) {
+                printf("│   ├── Events received: %d\n", stats->events_received);
+                printf("│   ├── Connection attempts: %d\n", stats->connection_attempts);
+                printf("│   ├── Connection failures: %d\n", stats->connection_failures);
+                printf("│   ├── Events published: %d (OK: %d, Failed: %d)\n",
+                       stats->events_published, stats->events_published_ok, stats->events_published_failed);
+                printf("│   ├── Ping latency: %.2f ms\n", stats->ping_latency_current);
+                printf("│   └── Query latency: %.2f ms\n", stats->query_latency_avg);
+            }
+
+            free(relay_urls[i]);
+        }
+        free(relay_urls);
+        free(statuses);
+    }
+    printf("\n");
+}
+
+
+// Async publish callback context
+typedef struct {
+    int total_relays;
+    int responses_received;
+    int success_count;
+    time_t start_time;
+} async_publish_context_t;
+
+// Async publish callback - called for each relay response
+void async_publish_callback(const char* relay_url, const char* event_id,
+                           int success, const char* message, void* user_data) {
+    async_publish_context_t* ctx = (async_publish_context_t*)user_data;
+    
+    ctx->responses_received++;
+    if (success) {
+        ctx->success_count++;
+    }
+    
+    // Calculate elapsed time
+    time_t now = time(NULL);
+    double elapsed = difftime(now, ctx->start_time);
+    
+    // Log to file with real-time feedback
+    char timestamp[26];
+    ctime_r(&now, timestamp);
+    timestamp[24] = '\0';
+    
+    if (success) {
+        printf("✅ %s: Published successfully (%.1fs)\n", relay_url, elapsed);
+        dprintf(log_fd, "[%s] ✅ ASYNC: %s published successfully (%.1fs)\n",
+                timestamp, relay_url, elapsed);
+    } else {
+        printf("❌ %s: Failed - %s (%.1fs)\n", relay_url, message ? message : "unknown error", elapsed);
+        dprintf(log_fd, "[%s] ❌ ASYNC: %s failed - %s (%.1fs)\n",
+                timestamp, relay_url, message ? message : "unknown error", elapsed);
+    }
+    
+    // Show progress
+    printf("   Progress: %d/%d responses received\n", ctx->responses_received, ctx->total_relays);
+    
+    if (ctx->responses_received >= ctx->total_relays) {
+        printf("\n🎉 All relays responded! Final result: %d/%d successful\n",
+               ctx->success_count, ctx->total_relays);
+        dprintf(log_fd, "[%s] 🎉 ASYNC: All relays responded - %d/%d successful\n\n",
+                timestamp, ctx->success_count, ctx->total_relays);
+    }
+}
+
+// Publish test event with async callbacks
+void publish_event() {
+    if (!pool) {
+        printf("❌ Pool not started\n");
+        return;
+    }
+
+    printf("\n--- Publish Test Event ---\n");
+
+    // Generate random keypair
+    unsigned char private_key[32], public_key[32];
+    if (nostr_generate_keypair(private_key, public_key) != NOSTR_SUCCESS) {
+        printf("❌ Failed to generate keypair\n");
+        return;
+    }
+
+    // Get current timestamp
+    time_t now = time(NULL);
+
+    // Format content with date/time
+    char content[256];
+    struct tm* tm_info = localtime(&now);
+    strftime(content, sizeof(content), "Test post at %Y-%m-%d %H:%M:%S", tm_info);
+
+    // Create kind 1 event
+    cJSON* event = nostr_create_and_sign_event(1, content, NULL, private_key, now);
+    if (!event) {
+        printf("❌ Failed to create event\n");
+        return;
+    }
+
+    // Get relay URLs from pool
+    char** relay_urls = NULL;
+    nostr_pool_relay_status_t* statuses = NULL;
+    int relay_count = nostr_relay_pool_list_relays(pool, &relay_urls, &statuses);
+
+    if (relay_count <= 0) {
+        printf("❌ No relays in pool\n");
+        cJSON_Delete(event);
+        return;
+    }
+
+    printf("📤 Publishing event to %d relay(s)...\n", relay_count);
+    printf("Watch for real-time responses below:\n\n");
+
+    // Setup callback context
+    async_publish_context_t ctx = {0};
+    ctx.total_relays = relay_count;
+    ctx.start_time = time(NULL);
+
+    // Log the event
+    char* event_json = cJSON_Print(event);
+    char timestamp[26];
+    ctime_r(&now, timestamp);
+    timestamp[24] = '\0';
+    dprintf(log_fd, "[%s] 📤 Publishing test event\n", timestamp);
+    dprintf(log_fd, "Event: %s\n\n", event_json);
+    free(event_json);
+
+    // Publish using async function
+    int sent_count = nostr_relay_pool_publish_async(pool, (const char**)relay_urls,
+                                                   relay_count, event,
+                                                   async_publish_callback, &ctx);
+
+    if (sent_count > 0) {
+        printf("📡 Event sent to %d/%d relays, waiting for responses...\n\n",
+               sent_count, relay_count);
+        
+        // Wait for all responses or timeout (10 seconds)
+        time_t wait_start = time(NULL);
+        while (ctx.responses_received < ctx.total_relays &&
+               (time(NULL) - wait_start) < 10) {
+            // Let the polling thread process messages
+            usleep(100000); // 100ms
+        }
+        
+        if (ctx.responses_received < ctx.total_relays) {
+            printf("\n⏰ Timeout reached - %d/%d relays responded\n",
+                   ctx.responses_received, ctx.total_relays);
+        }
+    } else {
+        printf("❌ Failed to send event to any relays\n");
+    }
+
+    // Cleanup
+    for (int i = 0; i < relay_count; i++) {
+        free(relay_urls[i]);
+    }
+    free(relay_urls);
+    free(statuses);
+    cJSON_Delete(event);
+}
+
+int main() {
+    // Setup logging to file
+    log_fd = open("pool.log", O_WRONLY | O_CREAT | O_TRUNC, 0644);
+    if (log_fd == -1) {
+        fprintf(stderr, "❌ Failed to open pool.log for writing\n");
+        return 1;
+    }
+
+    // Initialize NOSTR library
+    if (nostr_init() != NOSTR_SUCCESS) {
+        fprintf(stderr, "❌ Failed to initialize NOSTR library\n");
+        close(log_fd);
+        return 1;
+    }
+
+    // Setup signal handler
+    signal(SIGINT, signal_handler);
+    signal(SIGTERM, signal_handler);
+
+    // Start polling thread
+    if (pthread_create(&poll_thread, NULL, poll_thread_func, NULL) != 0) {
+        fprintf(stderr, "❌ Failed to create polling thread\n");
+        nostr_cleanup();
+        close(log_fd);
+        return 1;
+    }
+
+    printf("🔗 NOSTR Relay Pool Interactive Test\n");
+    printf("=====================================\n");
+    printf("All event output is logged to pool.log\n");
+    printf("Press Ctrl+C to exit\n\n");
+
+    time_t now = time(NULL);
+    char timestamp[26];
+    ctime_r(&now, timestamp);
+    timestamp[24] = '\0';
+    dprintf(log_fd, "[%s] 🚀 Pool test started\n\n", timestamp);
+
+    // Main menu loop
+    while (running) {
+        print_menu();
+
+        char choice;
+        if (scanf("%c", &choice) != 1) {
+            break;
+        }
+
+        // Consume newline
+        int c;
+        while ((c = getchar()) != '\n' && c != EOF);
+
+        switch (choice) {
+            case '1': { // Start Pool
+                if (pool) {
+                    printf("❌ Pool already started\n");
+                    break;
+                }
+
+                // Create pool with custom reconnection configuration for faster testing
+                nostr_pool_reconnect_config_t config = *nostr_pool_reconnect_config_default();
+                config.ping_interval_seconds = 5; // Ping every 5 seconds for testing
+                pool = nostr_relay_pool_create(&config);
+                if (!pool) {
+                    printf("❌ Failed to create pool\n");
+                    break;
+                }
+
+                if (nostr_relay_pool_add_relay(pool, "ws://localhost:7555") != NOSTR_SUCCESS) {
+                    printf("❌ Failed to add default relay\n");
+                    nostr_relay_pool_destroy(pool);
+                    pool = NULL;
+                    break;
+                }
+
+                printf("✅ Pool started with ws://localhost:7555\n");
+
+                now = time(NULL);
+                ctime_r(&now, timestamp);
+                timestamp[24] = '\0';
+                dprintf(log_fd, "[%s] 🏊 Pool started with default relay\n\n", timestamp);
+                break;
+            }
+
+            case '2': { // Stop Pool
+                if (!pool) {
+                    printf("❌ Pool not started\n");
+                    break;
+                }
+
+                // Close all subscriptions
+                for (int i = 0; i < subscription_count; i++) {
+                    if (subscriptions[i]) {
+                        nostr_pool_subscription_close(subscriptions[i]);
+                    }
+                }
+                free(subscriptions);
+                subscriptions = NULL;
+                subscription_count = 0;
+                subscription_capacity = 0;
+
+                nostr_relay_pool_destroy(pool);
+                pool = NULL;
+
+                printf("✅ Pool stopped\n");
+
+                now = time(NULL);
+                ctime_r(&now, timestamp);
+                timestamp[24] = '\0';
+                dprintf(log_fd, "[%s] 🛑 Pool stopped\n\n", timestamp);
+                break;
+            }
+
+            case '3': { // Add relay
+                if (!pool) {
+                    printf("❌ Pool not started\n");
+                    break;
+                }
+
+                char* url = get_input("Enter relay URL", "wss://relay.example.com");
+                if (url && strlen(url) > 0) {
+                    if (nostr_relay_pool_add_relay(pool, url) == NOSTR_SUCCESS) {
+                        printf("✅ Relay added: %s\n", url);
+                        printf("⏳ Attempting to connect...\n");
+                        
+                        // Give it a moment to attempt connection
+                        sleep(2);
+                        
+                        // Check connection status and show any errors
+                        nostr_pool_relay_status_t status = nostr_relay_pool_get_relay_status(pool, url);
+                        const char* error_msg = nostr_relay_pool_get_relay_last_connection_error(pool, url);
+                        
+                        switch (status) {
+                            case NOSTR_POOL_RELAY_CONNECTED:
+                                printf("🟢 Successfully connected to %s\n", url);
+                                break;
+                            case NOSTR_POOL_RELAY_CONNECTING:
+                                printf("🟡 Still connecting to %s...\n", url);
+                                break;
+                            case NOSTR_POOL_RELAY_DISCONNECTED:
+                                printf("⚪ Disconnected from %s\n", url);
+                                if (error_msg) {
+                                    printf("   Last error: %s\n", error_msg);
+                                }
+                                break;
+                            case NOSTR_POOL_RELAY_ERROR:
+                                printf("🔴 Connection error for %s\n", url);
+                                if (error_msg) {
+                                    printf("   Error details: %s\n", error_msg);
+                                }
+                                break;
+                            default:
+                                printf("❓ Unknown status for %s\n", url);
+                                break;
+                        }
+
+                        now = time(NULL);
+                        ctime_r(&now, timestamp);
+                        timestamp[24] = '\0';
+                        dprintf(log_fd, "[%s] ➕ Relay added: %s (status: %d)\n", timestamp, url, status);
+                        if (error_msg) {
+                            dprintf(log_fd, "   Connection error: %s\n", error_msg);
+                        }
+                        dprintf(log_fd, "\n");
+                    } else {
+                        printf("❌ Failed to add relay to pool\n");
+                    }
+                }
+                free(url);
+                break;
+            }
+
+            case '4': { // Remove relay
+                if (!pool) {
+                    printf("❌ Pool not started\n");
+                    break;
+                }
+
+                char* url = get_input("Enter relay URL to remove", NULL);
+                if (url && strlen(url) > 0) {
+                    if (nostr_relay_pool_remove_relay(pool, url) == NOSTR_SUCCESS) {
+                        printf("✅ Relay removed: %s\n", url);
+
+                        now = time(NULL);
+                        ctime_r(&now, timestamp);
+                        timestamp[24] = '\0';
+                        dprintf(log_fd, "[%s] ➖ Relay removed: %s\n\n", timestamp, url);
+                    } else {
+                        printf("❌ Failed to remove relay\n");
+                    }
+                }
+                free(url);
+                break;
+            }
+
+            case '5': // Add subscription
+                add_subscription();
+                break;
+
+            case '6': // Remove subscription
+                remove_subscription();
+                break;
+
+            case '7': // Show status
+                show_pool_status();
+                break;
+
+            case '8': { // Test reconnection
+                if (!pool) {
+                    printf("❌ Pool not started\n");
+                    break;
+                }
+
+                char** relay_urls = NULL;
+                nostr_pool_relay_status_t* statuses = NULL;
+                int relay_count = nostr_relay_pool_list_relays(pool, &relay_urls, &statuses);
+
+                if (relay_count <= 0) {
+                    printf("❌ No relays in pool\n");
+                    break;
+                }
+
+                printf("\n--- Test Reconnection ---\n");
+                printf("Available relays:\n");
+                for (int i = 0; i < relay_count; i++) {
+                    printf("%d. %s (%s)\n", i + 1, relay_urls[i],
+                           statuses[i] == NOSTR_POOL_RELAY_CONNECTED ? "CONNECTED" : "NOT CONNECTED");
+                }
+
+                char* choice_input = get_input("Enter relay number to test reconnection with", NULL);
+                if (!choice_input || strlen(choice_input) == 0) {
+                    for (int i = 0; i < relay_count; i++) free(relay_urls[i]);
+                    free(relay_urls);
+                    free(statuses);
+                    free(choice_input);
+                    break;
+                }
+
+                int choice = atoi(choice_input) - 1;
+                free(choice_input);
+
+                if (choice < 0 || choice >= relay_count) {
+                    printf("❌ Invalid relay number\n");
+                    for (int i = 0; i < relay_count; i++) free(relay_urls[i]);
+                    free(relay_urls);
+                    free(statuses);
+                    break;
+                }
+
+                printf("🔄 Testing reconnection with %s...\n", relay_urls[choice]);
+                printf("   The pool is configured with automatic reconnection enabled.\n");
+                printf("   If the connection drops, it will automatically attempt to reconnect\n");
+                printf("   with exponential backoff (1s → 2s → 4s → 8s → 16s → 30s max).\n");
+                printf("   Connection health is monitored with ping/pong every 30 seconds.\n");
+
+                time_t now = time(NULL);
+                char timestamp[26];
+                ctime_r(&now, timestamp);
+                timestamp[24] = '\0';
+                dprintf(log_fd, "[%s] 🔄 TEST: Testing reconnection behavior with %s\n", timestamp, relay_urls[choice]);
+                dprintf(log_fd, "   Pool configured with: auto-reconnect=ON, max_attempts=10, ping_interval=30s\n\n");
+
+                printf("✅ Reconnection test initiated. Monitor the status and logs for reconnection activity.\n");
+
+                for (int i = 0; i < relay_count; i++) free(relay_urls[i]);
+                free(relay_urls);
+                free(statuses);
+                break;
+            }
+
+            case '9': // Publish Event
+                publish_event();
+                break;
+
+            case '0': // Exit
+                running = 0;
+                break;
+
+            default:
+                printf("❌ Invalid choice\n");
+                break;
+        }
+    }
+
+    printf("\n🧹 Cleaning up...\n");
+
+    // Stop polling thread
+    running = 0;
+    pthread_join(poll_thread, NULL);
+
+    // Clean up pool and subscriptions
+    if (pool) {
+        for (int i = 0; i < subscription_count; i++) {
+            if (subscriptions[i]) {
+                nostr_pool_subscription_close(subscriptions[i]);
+            }
+        }
+        free(subscriptions);
+        nostr_relay_pool_destroy(pool);
+        printf("✅ Pool destroyed\n");
+    }
+
+    // Cleanup
+    nostr_cleanup();
+    close(log_fd);
+
+    printf("👋 Test completed\n");
+    return 0;
+}

examples/send_nip17_dm.c

@@ -0,0 +1,243 @@
+/*
+ * NIP-17 Private Direct Messages - Command Line Application
+ *
+ * This example demonstrates how to send NIP-17 private direct messages
+ * using the Nostr Core Library.
+ *
+ * Usage:
+ *   ./send_nip17_dm <recipient_pubkey> <message> [sender_nsec]
+ *
+ * Arguments:
+ *   recipient_pubkey: The npub or hex public key of the recipient
+ *   message: The message to send
+ *   sender_nsec: (optional) The nsec private key to use for sending.
+ *                If not provided, uses a default test key.
+ *
+ * Example:
+ *   ./send_nip17_dm npub1example... "Hello from NIP-17!" nsec1test...
+ */
+
+#define _GNU_SOURCE
+#define _POSIX_C_SOURCE 200809L
+
+#include "../nostr_core/nostr_core.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+// Default test private key (for demonstration - DO NOT USE IN PRODUCTION)
+#define DEFAULT_SENDER_NSEC "nsec12kgt0dv2k2safv6s32w8f89z9uw27e68hjaa0d66c5xvk70ezpwqncd045"
+
+// Default relay for sending DMs
+#define DEFAULT_RELAY "wss://relay.laantungir.net"
+
+// Progress callback for publishing
+void publish_progress_callback(const char* relay_url, const char* status,
+                              const char* message, int success_count,
+                              int total_relays, int completed_relays, void* user_data) {
+    (void)user_data;
+
+    if (relay_url) {
+        printf("📡 [%s]: %s", relay_url, status);
+        if (message) {
+            printf(" - %s", message);
+        }
+        printf(" (%d/%d completed, %d successful)\n", completed_relays, total_relays, success_count);
+    } else {
+        printf("📡 PUBLISH COMPLETE: %d/%d successful\n", success_count, total_relays);
+    }
+}
+
+/**
+ * Convert npub to hex if needed
+ */
+int convert_pubkey_to_hex(const char* input_pubkey, char* output_hex) {
+    // Check if it's already hex (64 characters)
+    if (strlen(input_pubkey) == 64) {
+        // Assume it's already hex
+        strcpy(output_hex, input_pubkey);
+        return 0;
+    }
+
+    // Check if it's an npub (starts with "npub1")
+    if (strncmp(input_pubkey, "npub1", 5) == 0) {
+        // Convert npub to hex
+        unsigned char pubkey_bytes[32];
+        if (nostr_decode_npub(input_pubkey, pubkey_bytes) != 0) {
+            fprintf(stderr, "Error: Invalid npub format\n");
+            return -1;
+        }
+        nostr_bytes_to_hex(pubkey_bytes, 32, output_hex);
+        return 0;
+    }
+
+    fprintf(stderr, "Error: Public key must be 64-character hex or valid npub\n");
+    return -1;
+}
+
+/**
+ * Convert nsec to private key bytes if needed
+ */
+int convert_nsec_to_private_key(const char* input_nsec, unsigned char* private_key) {
+    // Check if it's already hex (64 characters)
+    if (strlen(input_nsec) == 64) {
+        // Convert hex to bytes
+        if (nostr_hex_to_bytes(input_nsec, private_key, 32) != 0) {
+            fprintf(stderr, "Error: Invalid hex private key\n");
+            return -1;
+        }
+        return 0;
+    }
+
+    // Check if it's an nsec (starts with "nsec1")
+    if (strncmp(input_nsec, "nsec1", 5) == 0) {
+        // Convert nsec directly to private key bytes
+        if (nostr_decode_nsec(input_nsec, private_key) != 0) {
+            fprintf(stderr, "Error: Invalid nsec format\n");
+            return -1;
+        }
+        return 0;
+    }
+
+    fprintf(stderr, "Error: Private key must be 64-character hex or valid nsec\n");
+    return -1;
+}
+
+/**
+ * Main function
+ */
+int main(int argc, char* argv[]) {
+    if (argc < 3 || argc > 4) {
+        fprintf(stderr, "Usage: %s <recipient_pubkey> <message> [sender_nsec]\n\n", argv[0]);
+        fprintf(stderr, "Arguments:\n");
+        fprintf(stderr, "  recipient_pubkey: npub or hex public key of recipient\n");
+        fprintf(stderr, "  message: The message to send\n");
+        fprintf(stderr, "  sender_nsec: (optional) nsec private key. Uses test key if not provided.\n\n");
+        fprintf(stderr, "Example:\n");
+        fprintf(stderr, "  %s npub1example... \"Hello!\" nsec1test...\n", argv[0]);
+        return 1;
+    }
+
+    const char* recipient_pubkey_input = argv[1];
+    const char* message = argv[2];
+    const char* sender_nsec_input = (argc >= 4) ? argv[3] : DEFAULT_SENDER_NSEC;
+
+    printf("🧪 NIP-17 Private Direct Message Sender\n");
+    printf("======================================\n\n");
+
+    // Initialize crypto
+    if (nostr_init() != NOSTR_SUCCESS) {
+        fprintf(stderr, "Failed to initialize crypto\n");
+        return 1;
+    }
+
+    // Convert recipient pubkey
+    char recipient_pubkey_hex[65];
+    if (convert_pubkey_to_hex(recipient_pubkey_input, recipient_pubkey_hex) != 0) {
+        return 1;
+    }
+
+    // Convert sender private key
+    unsigned char sender_privkey[32];
+    if (convert_nsec_to_private_key(sender_nsec_input, sender_privkey) != 0) {
+        return 1;
+    }
+
+    // Derive sender public key for display
+    unsigned char sender_pubkey_bytes[32];
+    char sender_pubkey_hex[65];
+    if (nostr_ec_public_key_from_private_key(sender_privkey, sender_pubkey_bytes) != 0) {
+        fprintf(stderr, "Failed to derive sender public key\n");
+        return 1;
+    }
+    nostr_bytes_to_hex(sender_pubkey_bytes, 32, sender_pubkey_hex);
+
+    printf("📤 Sender: %s\n", sender_pubkey_hex);
+    printf("📥 Recipient: %s\n", recipient_pubkey_hex);
+    printf("💬 Message: %s\n", message);
+    printf("🌐 Relay: %s\n\n", DEFAULT_RELAY);
+
+    // Create DM event
+    printf("💬 Creating DM event...\n");
+    const char* recipient_pubkeys[] = {recipient_pubkey_hex};
+    cJSON* dm_event = nostr_nip17_create_chat_event(
+        message,
+        recipient_pubkeys,
+        1,
+        "NIP-17 CLI",  // subject
+        NULL,          // no reply
+        DEFAULT_RELAY, // relay hint
+        sender_pubkey_hex
+    );
+
+    if (!dm_event) {
+        fprintf(stderr, "Failed to create DM event\n");
+        return 1;
+    }
+
+    printf("✅ Created DM event (kind 14)\n");
+
+    // Send DM (create gift wraps)
+    printf("🎁 Creating gift wraps...\n");
+    cJSON* gift_wraps[10];  // Max 10 gift wraps
+    int gift_wrap_count = nostr_nip17_send_dm(
+        dm_event,
+        recipient_pubkeys,
+        1,
+        sender_privkey,
+        gift_wraps,
+        10,
+        0
+    );
+
+    cJSON_Delete(dm_event);  // Original DM event no longer needed
+
+    if (gift_wrap_count <= 0) {
+        fprintf(stderr, "Failed to create gift wraps\n");
+        return 1;
+    }
+
+    printf("✅ Created %d gift wrap(s)\n", gift_wrap_count);
+
+    // Publish the gift wrap to relay
+    printf("\n📤 Publishing gift wrap to relay...\n");
+
+    const char* relay_urls[] = {DEFAULT_RELAY};
+    int success_count = 0;
+    publish_result_t* publish_results = synchronous_publish_event_with_progress(
+        relay_urls,
+        1,  // single relay
+        gift_wraps[0],  // Send the first gift wrap
+        &success_count,
+        10,  // 10 second timeout
+        publish_progress_callback,
+        NULL,  // no user data
+        0,     // NIP-42 disabled
+        NULL   // no private key for auth
+    );
+
+    if (!publish_results || success_count != 1) {
+        fprintf(stderr, "\n❌ Failed to publish gift wrap (success_count: %d)\n", success_count);
+        // Clean up gift wraps
+        for (int i = 0; i < gift_wrap_count; i++) {
+            cJSON_Delete(gift_wraps[i]);
+        }
+        if (publish_results) free(publish_results);
+        return 1;
+    }
+
+    printf("\n✅ Successfully published NIP-17 DM!\n");
+
+    // Clean up
+    free(publish_results);
+    for (int i = 0; i < gift_wrap_count; i++) {
+        cJSON_Delete(gift_wraps[i]);
+    }
+
+    nostr_cleanup();
+
+    printf("\n🎉 DM sent successfully! The recipient can now decrypt it using their private key.\n");
+
+    return 0;
+}

examples/timestamping.c

@@ -0,0 +1,328 @@
+/*
+ * NIP-03 OpenTimestamps Example
+ *
+ * This example demonstrates the full NIP-03 timestamping workflow:
+ * 1. Create a Nostr event
+ * 2. Submit the event ID to an OpenTimestamps calendar
+ * 3. Poll for proof completion (Bitcoin attestation)
+ * 4. Create a NIP-03 proof event (kind 1040)
+ * 5. Verify the proof
+ *
+ * Usage:
+ *   ./timestamping                    # Create and timestamp a test event
+ *   ./timestamping <event_id>         # Timestamp an existing event ID
+ *   ./timestamping --verify <ots_b64> # Verify a proof
+ *
+ * Note: Bitcoin attestations typically take 1-12 hours to appear.
+ * The OpenTimestamps calendars commit to the Bitcoin blockchain
+ * periodically, so you may need to wait and poll for completion.
+ */
+
+#define _POSIX_C_SOURCE 200809L
+
+#include "nostr_core/nostr_core.h"
+#include "nostr_core/nip003.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+
+#define DEFAULT_CALENDAR_URL "https://alice.btc.calendar.opentimestamps.org"
+#define POLL_INTERVAL_SEC 300  /* 5 minutes */
+#define MAX_POLL_ATTEMPTS 144  /* 12 hours total */
+
+static void print_usage(const char* prog_name) {
+    printf("NIP-03 OpenTimestamps Example\n");
+    printf("\n");
+    printf("Usage:\n");
+    printf("  %s                        Create and timestamp a test event\n", prog_name);
+    printf("  %s <event_id>             Timestamp an existing event ID (64-char hex)\n", prog_name);
+    printf("  %s --verify <ots_b64>     Verify a base64-encoded OTS proof\n", prog_name);
+    printf("  %s --check <ots_b64>      Check if a proof is complete\n", prog_name);
+    printf("\n");
+    printf("Options:\n");
+    printf("  --calendar <url>          Use a specific OTS calendar URL\n");
+    printf("  --interval <seconds>      Poll interval in seconds (default: %d)\n", POLL_INTERVAL_SEC);
+    printf("  --max-attempts <n>        Max poll attempts (default: %d)\n", MAX_POLL_ATTEMPTS);
+    printf("\n");
+    printf("Common calendar URLs:\n");
+    printf("  https://alice.btc.calendar.opentimestamps.org\n");
+    printf("  https://bob.btc.calendar.opentimestamps.org\n");
+    printf("  https://finney.calendar.eternitywall.com\n");
+}
+
+static void print_attestation_info(const char* ots_b64) {
+    int has_bitcoin = 0, has_litecoin = 0, has_pending = 0;
+    uint64_t btc_height = 0, ltc_height = 0;
+    char* pending_uri = NULL;
+
+    if (nostr_nip03_get_attestation_info(ots_b64, &has_bitcoin, &has_litecoin, &has_pending,
+                                         &btc_height, &ltc_height, &pending_uri) != 0) {
+        printf("  ⚠️ Failed to parse attestation info\n");
+        return;
+    }
+
+    if (has_bitcoin) {
+        printf("  ✅ Bitcoin attestation: block height %llu\n", (unsigned long long)btc_height);
+    }
+    if (has_litecoin) {
+        printf("  ✅ Litecoin attestation: block height %llu\n", (unsigned long long)ltc_height);
+    }
+    if (has_pending) {
+        if (pending_uri) {
+            printf("  ⏳ Pending at: %s\n", pending_uri);
+            free(pending_uri);
+        }
+    }
+    if (!has_bitcoin && !has_litecoin && !has_pending) {
+        printf("  ⚠️ No attestations found\n");
+    }
+}
+
+static int do_timestamp(const char* event_id_hex, const char* calendar_url,
+                        int poll_interval, int max_attempts) {
+    printf("📅 NIP-03 Timestamping\n");
+    printf("   Event ID: %s\n", event_id_hex);
+    printf("   Calendar: %s\n", calendar_url);
+    printf("\n");
+
+    /* Step 1: Submit to calendar */
+    printf("📤 Submitting to OpenTimestamps calendar...\n");
+    char* ots_b64 = nostr_nip03_request_timestamp(event_id_hex, calendar_url, 30);
+    if (!ots_b64) {
+        printf("❌ Failed to submit to calendar.\n");
+        printf("   Check your internet connection and the calendar URL.\n");
+        return 1;
+    }
+
+    printf("✅ Initial proof received.\n");
+    print_attestation_info(ots_b64);
+    printf("\n");
+
+    /* Step 2: Poll for completion */
+    printf("⏳ Polling for Bitcoin attestation (every %d seconds, max %d attempts)...\n",
+           poll_interval, max_attempts);
+
+    int complete = 0;
+    int attempts = 0;
+
+    while (!complete && attempts < max_attempts) {
+        attempts++;
+        complete = nostr_nip03_is_proof_complete(ots_b64);
+
+        time_t now = time(NULL);
+        char time_str[26];
+        ctime_r(&now, time_str);
+        time_str[24] = '\0';
+
+        printf("[%s] Attempt %d/%d: %s\n", time_str, attempts, max_attempts,
+               complete ? "✅ COMPLETE" : "⏳ PENDING");
+
+        if (!complete) {
+            sleep(poll_interval);
+
+            /* Try to upgrade the proof */
+            char* upgraded = nostr_nip03_upgrade_proof(ots_b64, calendar_url, 30);
+            if (upgraded) {
+                free(ots_b64);
+                ots_b64 = upgraded;
+            }
+        }
+    }
+
+    if (complete) {
+        printf("\n🎉 SUCCESS! The proof is now complete with a Bitcoin attestation.\n");
+        print_attestation_info(ots_b64);
+
+        /* Verify the proof */
+        uint64_t block_height = 0;
+        int verify_rc = nostr_nip03_verify_proof(ots_b64, event_id_hex, &block_height, NULL);
+        if (verify_rc == 0) {
+            printf("   ✅ Proof verified: digest matches, Bitcoin height=%llu\n",
+                   (unsigned long long)block_height);
+        } else {
+            printf("   ⚠️ Proof verification returned: %d\n", verify_rc);
+        }
+
+        /* Create the NIP-03 proof event */
+        unsigned char private_key[32];
+        unsigned char public_key[32];
+        nostr_generate_keypair(private_key, public_key);
+
+        cJSON* proof_event = nostr_nip03_create_proof_event(event_id_hex, 1, ots_b64, NULL, private_key);
+        if (proof_event) {
+            char* json = cJSON_Print(proof_event);
+            printf("\n📄 NIP-03 Proof Event (kind 1040):\n%s\n", json);
+            free(json);
+            cJSON_Delete(proof_event);
+        }
+
+        /* Print the base64 OTS data for storage */
+        printf("\n📦 OTS proof (base64, save this):\n%s\n", ots_b64);
+    } else {
+        printf("\n⏳ Proof is still pending after %d attempts.\n", attempts);
+        printf("   Bitcoin attestations can take several hours.\n");
+        printf("   Save the OTS proof and check again later:\n%s\n", ots_b64);
+    }
+
+    free(ots_b64);
+    return complete ? 0 : 2;
+}
+
+static int do_verify(const char* ots_b64, const char* target_digest_hex) {
+    printf("🔍 Verifying OTS proof...\n\n");
+
+    uint64_t block_height = 0;
+    time_t block_time = 0;
+
+    int rc = nostr_nip03_verify_proof(ots_b64, target_digest_hex, &block_height, &block_time);
+
+    switch (rc) {
+        case 0:
+            printf("✅ Proof verified!\n");
+            printf("   Bitcoin block height: %llu\n", (unsigned long long)block_height);
+            print_attestation_info(ots_b64);
+            return 0;
+        case 1:
+            printf("⏳ Proof is valid but has no Bitcoin attestation (still pending).\n");
+            print_attestation_info(ots_b64);
+            return 1;
+        case -1:
+            printf("❌ Failed to parse OTS proof.\n");
+            return 1;
+        case -2:
+            printf("❌ Digest mismatch! The proof does not match the expected digest.\n");
+            return 1;
+        default:
+            printf("❌ Unknown error: %d\n", rc);
+            return 1;
+    }
+}
+
+static int do_check(const char* ots_b64) {
+    printf("🔎 Checking OTS proof status...\n\n");
+
+    int complete = nostr_nip03_is_proof_complete(ots_b64);
+
+    if (complete == 1) {
+        printf("✅ Proof is COMPLETE (has Bitcoin/Litecoin attestation)\n");
+    } else if (complete == 0) {
+        printf("⏳ Proof is PENDING (no Bitcoin attestation yet)\n");
+    } else {
+        printf("❌ Failed to parse proof (error)\n");
+        return 1;
+    }
+
+    print_attestation_info(ots_b64);
+    return 0;
+}
+
+int main(int argc, char* argv[]) {
+    if (nostr_init() != NOSTR_SUCCESS) {
+        fprintf(stderr, "Failed to initialize NOSTR library\n");
+        return 1;
+    }
+
+    const char* calendar_url = DEFAULT_CALENDAR_URL;
+    int poll_interval = POLL_INTERVAL_SEC;
+    int max_attempts = MAX_POLL_ATTEMPTS;
+    const char* event_id = NULL;
+    const char* ots_b64 = NULL;
+    const char* verify_digest = NULL;
+
+    enum { MODE_TIMESTAMP, MODE_VERIFY, MODE_CHECK } mode = MODE_TIMESTAMP;
+
+    /* Parse arguments */
+    for (int i = 1; i < argc; i++) {
+        if (strcmp(argv[i], "--help") == 0 || strcmp(argv[i], "-h") == 0) {
+            print_usage(argv[0]);
+            nostr_cleanup();
+            return 0;
+        } else if (strcmp(argv[i], "--verify") == 0) {
+            mode = MODE_VERIFY;
+            /* OTS data is provided as a positional argument */
+        } else if (strcmp(argv[i], "--check") == 0) {
+            mode = MODE_CHECK;
+            /* OTS data is provided as a positional argument */
+        } else if (strcmp(argv[i], "--calendar") == 0 && i + 1 < argc) {
+            calendar_url = argv[++i];
+        } else if (strcmp(argv[i], "--interval") == 0 && i + 1 < argc) {
+            poll_interval = atoi(argv[++i]);
+        } else if (strcmp(argv[i], "--max-attempts") == 0 && i + 1 < argc) {
+            max_attempts = atoi(argv[++i]);
+        } else if (strcmp(argv[i], "--digest") == 0 && i + 1 < argc) {
+            verify_digest = argv[++i];
+        } else if (argv[i][0] != '-' && !event_id && !ots_b64) {
+            if (mode == MODE_VERIFY || mode == MODE_CHECK) {
+                if (!ots_b64) ots_b64 = argv[i];
+            } else {
+                event_id = argv[i];
+            }
+        }
+    }
+
+    int rc = 0;
+
+    switch (mode) {
+        case MODE_TIMESTAMP:
+            if (!event_id) {
+                /* Create a test event */
+                printf("🧪 Creating a test event to timestamp...\n");
+                unsigned char private_key[32];
+                unsigned char public_key[32];
+                nostr_generate_keypair(private_key, public_key);
+
+                char content[128];
+                snprintf(content, sizeof(content), "NIP-03 timestamp test at %ld", time(NULL));
+
+                cJSON* event = nostr_create_and_sign_event(1, content, NULL, private_key, 0);
+                if (!event) {
+                    printf("❌ Failed to create test event\n");
+                    nostr_cleanup();
+                    return 1;
+                }
+
+                cJSON* id_item = cJSON_GetObjectItem(event, "id");
+                if (!id_item || !cJSON_IsString(id_item)) {
+                    printf("❌ Failed to get event ID\n");
+                    cJSON_Delete(event);
+                    nostr_cleanup();
+                    return 1;
+                }
+
+                char* event_json = cJSON_Print(event);
+                printf("📄 Test event:\n%s\n\n", event_json);
+                free(event_json);
+
+                rc = do_timestamp(id_item->valuestring, calendar_url, poll_interval, max_attempts);
+                cJSON_Delete(event);
+            } else {
+                rc = do_timestamp(event_id, calendar_url, poll_interval, max_attempts);
+            }
+            break;
+
+        case MODE_VERIFY:
+            if (!ots_b64) {
+                printf("❌ Missing OTS proof (base64)\n");
+                print_usage(argv[0]);
+                rc = 1;
+            } else {
+                rc = do_verify(ots_b64, verify_digest);
+            }
+            break;
+
+        case MODE_CHECK:
+            if (!ots_b64) {
+                printf("❌ Missing OTS proof (base64)\n");
+                print_usage(argv[0]);
+                rc = 1;
+            } else {
+                rc = do_check(ots_b64);
+            }
+            break;
+    }
+
+    nostr_cleanup();
+    return rc;
+}

increment_and_push.sh

@@ -0,0 +1,183 @@
+#!/bin/bash
+
+# increment_and_push.sh - Version increment and git automation script
+# Usage:
+#   ./increment_and_push.sh "meaningful git comment"
+#   ./increment_and_push.sh --set-version vX.Y.Z "meaningful git comment"
+
+set -e  # Exit on error
+
+# Color constants
+RED='\033[31m'
+GREEN='\033[32m'
+YELLOW='\033[33m'
+BLUE='\033[34m'
+BOLD='\033[1m'
+RESET='\033[0m'
+
+# Function to print output with colors
+print_info() {
+    if [ "$USE_COLORS" = true ]; then
+        echo -e "${BLUE}[INFO]${RESET} $1"
+    else
+        echo "[INFO] $1"
+    fi
+}
+
+print_success() {
+    if [ "$USE_COLORS" = true ]; then
+        echo -e "${GREEN}${BOLD}[SUCCESS]${RESET} $1"
+    else
+        echo "[SUCCESS] $1"
+    fi
+}
+
+print_warning() {
+    if [ "$USE_COLORS" = true ]; then
+        echo -e "${YELLOW}[WARNING]${RESET} $1"
+    else
+        echo "[WARNING] $1"
+    fi
+}
+
+print_error() {
+    if [ "$USE_COLORS" = true ]; then
+        echo -e "${RED}${BOLD}[ERROR]${RESET} $1"
+    else
+        echo "[ERROR] $1"
+    fi
+}
+
+# Check if we're in the correct directory
+CURRENT_DIR=$(basename "$(pwd)")
+if [ "$CURRENT_DIR" != "nostr_core_lib" ]; then
+    print_error "Script must be run from the nostr_core_lib directory"
+    echo ""
+    echo "Current directory: $CURRENT_DIR"
+    echo "Expected directory: nostr_core_lib"
+    echo ""
+    echo "Please change to the nostr_core_lib directory first."
+    echo ""
+    exit 1
+fi
+
+# Check if git repository exists
+if ! git rev-parse --git-dir > /dev/null 2>&1; then
+    print_error "Not a git repository. Please initialize git first."
+    exit 1
+fi
+
+TARGET_VERSION=""
+COMMIT_MESSAGE=""
+
+# Parse arguments
+if [ "$1" = "--set-version" ]; then
+    if [ $# -lt 3 ]; then
+        print_error "Usage: $0 --set-version vX.Y.Z \"meaningful git comment\""
+        echo ""
+        echo "Example: $0 --set-version v0.6.0 \"Release v0.6.0 with ESP32 embedded support\""
+        echo ""
+        exit 1
+    fi
+    TARGET_VERSION="$2"
+    COMMIT_MESSAGE="$3"
+else
+    if [ $# -eq 0 ]; then
+        print_error "Usage: $0 \"meaningful git comment\""
+        echo ""
+        echo "Example: $0 \"Add enhanced subscription functionality\""
+        echo ""
+        exit 1
+    fi
+    COMMIT_MESSAGE="$1"
+fi
+
+# Check if nostr_core.h exists
+if [ ! -f "nostr_core/nostr_core.h" ]; then
+    print_error "nostr_core/nostr_core.h not found"
+    exit 1
+fi
+
+print_info "Starting version increment and push process..."
+
+# Extract current version from nostr_core.h
+CURRENT_VERSION=$(grep '#define VERSION ' nostr_core/nostr_core.h | cut -d'"' -f2)
+if [ -z "$CURRENT_VERSION" ]; then
+    print_error "Could not find VERSION define in nostr_core.h"
+    exit 1
+fi
+
+# Extract version components
+VERSION_MAJOR=$(grep '#define VERSION_MAJOR ' nostr_core/nostr_core.h | awk '{print $3}')
+VERSION_MINOR=$(grep '#define VERSION_MINOR ' nostr_core/nostr_core.h | awk '{print $3}')
+VERSION_PATCH=$(grep '#define VERSION_PATCH ' nostr_core/nostr_core.h | awk '{print $3}')
+
+if [ -z "$VERSION_MAJOR" ] || [ -z "$VERSION_MINOR" ] || [ -z "$VERSION_PATCH" ]; then
+    print_error "Could not extract version components from nostr_core.h"
+    exit 1
+fi
+
+print_info "Current version: $CURRENT_VERSION (Major: $VERSION_MAJOR, Minor: $VERSION_MINOR, Patch: $VERSION_PATCH)"
+
+if [ -n "$TARGET_VERSION" ]; then
+    if [[ ! "$TARGET_VERSION" =~ ^v([0-9]+)\.([0-9]+)\.([0-9]+)$ ]]; then
+        print_error "Invalid target version format: $TARGET_VERSION (expected vX.Y.Z)"
+        exit 1
+    fi
+
+    NEW_VERSION="$TARGET_VERSION"
+    NEW_MAJOR="${BASH_REMATCH[1]}"
+    NEW_MINOR="${BASH_REMATCH[2]}"
+    NEW_PATCH="${BASH_REMATCH[3]}"
+else
+    # Increment patch version
+    NEW_MAJOR="$VERSION_MAJOR"
+    NEW_MINOR="$VERSION_MINOR"
+    NEW_PATCH=$((VERSION_PATCH + 1))
+    NEW_VERSION="v$NEW_MAJOR.$NEW_MINOR.$NEW_PATCH"
+fi
+
+print_info "New version will be: $NEW_VERSION"
+
+# Update version in nostr_core.h
+sed -i "s/#define VERSION .*/#define VERSION \"$NEW_VERSION\"/" nostr_core/nostr_core.h
+sed -i "s/#define VERSION_MAJOR .*/#define VERSION_MAJOR $NEW_MAJOR/" nostr_core/nostr_core.h
+sed -i "s/#define VERSION_MINOR .*/#define VERSION_MINOR $NEW_MINOR/" nostr_core/nostr_core.h
+sed -i "s/#define VERSION_PATCH .*/#define VERSION_PATCH $NEW_PATCH/" nostr_core/nostr_core.h
+
+print_success "Updated version in nostr_core.h"
+
+# Check if VERSION file exists and update it
+if [ -f "VERSION" ]; then
+    echo "$NEW_MAJOR.$NEW_MINOR.$NEW_PATCH" > VERSION
+    print_success "Updated VERSION file"
+fi
+
+# Check git status
+if ! git diff --quiet; then
+    print_info "Adding changes to git..."
+    git add .
+
+    print_info "Committing changes..."
+    git commit -m "$COMMIT_MESSAGE"
+
+    print_success "Changes committed"
+else
+    print_warning "No changes to commit"
+fi
+
+# Create and push git tag
+print_info "Creating git tag: $NEW_VERSION"
+git tag "$NEW_VERSION"
+
+print_info "Pushing commits and tags..."
+CURRENT_BRANCH=$(git branch --show-current)
+git push origin "$CURRENT_BRANCH"
+git push origin "$NEW_VERSION"
+
+print_success "Version $NEW_VERSION successfully released!"
+print_info "Git commit: $COMMIT_MESSAGE"
+print_info "Tag: $NEW_VERSION"
+
+echo ""
+echo "🎉 Release complete! Version $NEW_VERSION is now live."

nostr_core/NSIGNER_INTEGRATION.md

@@ -0,0 +1,481 @@
+# NSIGNER Integration in `nostr_core_lib`
+
+This document is the developer-facing integration contract for signer abstraction + nsigner client support in `nostr_core_lib`.
+
+For the concise overview, see the signer section in `README.md`.
+For implementation planning context, see `plans/nsigner_integration_plan.md`.
+
+## 1) Signer lifecycle and core verbs (exact signatures)
+
+From `nostr_core/nostr_signer.h`:
+
+```c
+typedef struct nostr_signer nostr_signer_t;
+
+/* Lifecycle */
+nostr_signer_t* nostr_signer_local(const unsigned char private_key[32]);
+void nostr_signer_free(nostr_signer_t* signer);
+
+/* Core verbs */
+int nostr_signer_get_public_key(nostr_signer_t* signer, char out_pubkey_hex[65]);
+int nostr_signer_sign_event(nostr_signer_t* signer, const cJSON* unsigned_event, cJSON** signed_event_out);
+
+/* Encryption verbs (for parity with upcoming remote backends) */
+int nostr_signer_nip04_encrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* plaintext,
+                               char** ciphertext_out);
+int nostr_signer_nip04_decrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* ciphertext,
+                               char** plaintext_out);
+int nostr_signer_nip44_encrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* plaintext,
+                               char** ciphertext_out);
+int nostr_signer_nip44_decrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* ciphertext,
+                               char** plaintext_out);
+```
+
+## 2) Remote signer factories + transport API (exact signatures)
+
+### 2.1 Signer-side remote factories (`nostr_core/nostr_signer.h`)
+
+```c
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+nostr_signer_t* nostr_signer_nsigner_unix(const char* socket_name, const char* role, int timeout_ms);
+nostr_signer_t* nostr_signer_nsigner_serial(const char* device_path, const char* role, int timeout_ms);
+nostr_signer_t* nostr_signer_nsigner_tcp(const char* host, int port, const char* role, int timeout_ms);
+nostr_signer_t* nostr_signer_nsigner_fds(int read_fd, int write_fd, const char* role, int timeout_ms);
+/* TCP mode requires auth envelope per n_signer; set this before making calls. */
+int nostr_signer_nsigner_set_auth(nostr_signer_t* signer,
+                                  const unsigned char auth_privkey[32],
+                                  const char* label);
+#endif
+```
+
+### 2.2 Transport constructors + framed I/O + discovery (`nostr_core/nsigner_transport.h`)
+
+```c
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+typedef struct nsigner_transport nsigner_transport_t;
+
+struct nsigner_transport {
+    int (*send_framed)(nsigner_transport_t* t, const char* json, size_t len);
+    int (*recv_framed)(nsigner_transport_t* t, char** out_json, size_t* out_len); /* caller frees *out_json */
+    void (*close)(nsigner_transport_t* t);
+    void* ctx;
+};
+
+/* Raw framed I/O helpers for existing connected file descriptors. */
+int nsigner_transport_send_framed_fd(int fd, const char* json, size_t len);
+int nsigner_transport_recv_framed_fd(int fd, char** out_json, size_t* out_len);
+
+/* UNIX abstract socket transport (socket_name without leading '@'). */
+nsigner_transport_t* nsigner_transport_open_unix(const char* socket_name, int timeout_ms);
+
+/* TCP transport (host + port), with IPv4/IPv6 resolution via getaddrinfo. */
+nsigner_transport_t* nsigner_transport_open_tcp(const char* host, int port, int timeout_ms);
+
+/* USB CDC-ACM serial transport (device path like /dev/ttyACM0). */
+nsigner_transport_t* nsigner_transport_open_serial(const char* device_path, int timeout_ms);
+
+/*
+ * Framed transport over existing file descriptors (read_fd, write_fd).
+ * close() closes both owned fds. If passing STDIN_FILENO/STDOUT_FILENO and you do not
+ * want them closed, pass dup()'d descriptors instead.
+ */
+nsigner_transport_t* nsigner_transport_open_fds(int read_fd, int write_fd, int timeout_ms);
+
+/* Enumerate /proc/net/unix abstract sockets beginning with @nsigner, returns count copied. */
+int nsigner_transport_list_unix(char names[][64], int max_names);
+
+/* Best-effort enumerate serial devices (e.g. /dev/ttyACM*), returns count copied. */
+int nsigner_transport_list_serial(char paths[][64], int max_paths);
+#endif
+```
+
+## 3) Client API + auth contract
+
+From `nostr_core/nsigner_client.h`:
+
+```c
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+typedef struct nsigner_client nsigner_client_t;
+
+nsigner_client_t* nsigner_client_new(nsigner_transport_t* transport); /* takes ownership of transport */
+void nsigner_client_free(nsigner_client_t* client);
+
+int nsigner_client_set_auth(nsigner_client_t* client, const unsigned char privkey[32], const char* label);
+
+int nsigner_client_call(nsigner_client_t* client,
+                        const char* method,
+                        cJSON* params,
+                        cJSON** out_result);
+
+const char* nsigner_client_last_error(const nsigner_client_t* client);
+int nsigner_client_compute_body_hash_hex(const cJSON* params, char out_hash_hex[65]);
+#endif
+```
+
+### n_signer wire methods
+
+The remote signer backend uses n_signer's role-based Nostr methods:
+
+- `nostr_get_public_key`
+- `nostr_sign_event`
+- `nostr_nip04_encrypt` / `nostr_nip04_decrypt`
+- `nostr_nip44_encrypt` / `nostr_nip44_decrypt`
+
+These wire names are distinct from both the public `nostr_signer_*` C API and the
+unprefixed NIP-46 method names. In particular, n_signer's unprefixed `get_public_key`
+is algorithm-based; this library uses `nostr_get_public_key` because remote signer
+factories select keys by `role` or `nostr_index`.
+
+### Auth and framing notes
+
+- Framing is 4-byte big-endian payload length + JSON payload.
+- Valid payload lengths are `1..65536` bytes (`NSIGNER_CLIENT_MAX_FRAME` in transport implementation).
+- TCP requires auth (`nostr_signer_nsigner_set_auth`), unix auth is optional.
+- Auth envelope is a kind-27235 event containing tags:
+  - `nsigner_rpc`
+  - `nsigner_method`
+  - `nsigner_body_hash`
+- `nsigner_body_hash` is SHA-256 of compact params JSON, or SHA-256 of literal `"null"` when params are null (`nsigner_client_compute_body_hash_hex`).
+
+## 4) Signer-aware higher-level APIs (`*_with_signer`)
+
+Below is the full list currently present in headers.
+
+### NIP-01 (`nostr_core/nip001.h`)
+
+```c
+cJSON* nostr_create_and_sign_event_with_signer(int kind, const char* content, cJSON* tags, nostr_signer_t* signer, time_t timestamp);
+```
+
+### NIP-17 (`nostr_core/nip017.h`)
+
+```c
+cJSON* nostr_nip17_create_relay_list_event_with_signer(const char** relay_urls,
+                                                       int num_relays,
+                                                       nostr_signer_t* signer);
+int nostr_nip17_send_dm_with_signer(cJSON* dm_event,
+                                    const char** recipient_pubkeys,
+                                    int num_recipients,
+                                    nostr_signer_t* signer,
+                                    cJSON** gift_wraps_out,
+                                    int max_gift_wraps,
+                                    long max_delay_sec);
+cJSON* nostr_nip17_receive_dm_with_signer(cJSON* gift_wrap,
+                                          nostr_signer_t* signer);
+```
+
+### NIP-42 (`nostr_core/nip042.h`)
+
+```c
+cJSON* nostr_nip42_create_auth_event_with_signer(const char* challenge,
+                                                 const char* relay_url,
+                                                 nostr_signer_t* signer,
+                                                 time_t timestamp);
+```
+
+### NIP-46 (`nostr_core/nip046.h`)
+
+```c
+cJSON* nostr_nip46_create_request_event_with_signer(const nostr_nip46_request_t* request,
+                                                    nostr_signer_t* signer,
+                                                    const unsigned char* recipient_public_key,
+                                                    time_t timestamp);
+cJSON* nostr_nip46_create_response_event_with_signer(const nostr_nip46_response_t* response,
+                                                     nostr_signer_t* signer,
+                                                     const unsigned char* recipient_public_key,
+                                                     time_t timestamp);
+int nostr_nip46_decrypt_event_with_signer(cJSON* event,
+                                          nostr_signer_t* signer,
+                                          char** output_out);
+int nostr_nip46_client_session_init_with_signer(nostr_nip46_client_session_t* session,
+                                                nostr_signer_t* signer,
+                                                const char* bunker_url);
+```
+
+### NIP-60 (`nostr_core/nip060.h`)
+
+```c
+cJSON* nostr_nip60_create_wallet_event_with_signer(const nostr_nip60_wallet_data_t* wallet_data,
+                                                   nostr_signer_t* signer,
+                                                   time_t timestamp);
+cJSON* nostr_nip60_create_token_event_with_signer(const nostr_nip60_token_data_t* token_data,
+                                                  nostr_signer_t* signer,
+                                                  time_t timestamp);
+cJSON* nostr_nip60_create_token_deletion_with_signer(const char* token_event_id,
+                                                     nostr_signer_t* signer,
+                                                     time_t timestamp);
+cJSON* nostr_nip60_create_rollover_token_with_signer(const nostr_nip60_token_data_t* remaining_proofs,
+                                                     const char** deleted_event_ids,
+                                                     int deleted_count,
+                                                     nostr_signer_t* signer,
+                                                     time_t timestamp);
+cJSON* nostr_nip60_create_history_event_with_signer(const nostr_nip60_history_data_t* history_data,
+                                                    nostr_signer_t* signer,
+                                                    time_t timestamp);
+cJSON* nostr_nip60_create_quote_event_with_signer(const char* quote_id,
+                                                  const char* mint_url,
+                                                  time_t expiration,
+                                                  nostr_signer_t* signer,
+                                                  time_t timestamp);
+```
+
+### NIP-61 (`nostr_core/nip061.h`)
+
+```c
+cJSON* nostr_nip61_create_nutzap_info_event_with_signer(const nostr_nip61_nutzap_info_t* info,
+                                                        nostr_signer_t* signer,
+                                                        time_t timestamp);
+cJSON* nostr_nip61_create_nutzap_event_with_signer(const nostr_nip61_nutzap_data_t* nutzap_data,
+                                                   nostr_signer_t* signer,
+                                                   time_t timestamp);
+cJSON* nostr_nip61_create_redemption_event_with_signer(const char* nutzap_event_id,
+                                                       const char* nutzap_relay_hint,
+                                                       const char* sender_pubkey,
+                                                       const char* created_token_event_id,
+                                                       const char* created_token_relay_hint,
+                                                       uint64_t amount,
+                                                       nostr_signer_t* signer,
+                                                       time_t timestamp);
+```
+
+### NIP-59 (`nostr_core/nip059.h`) (additional signer coverage present)
+
+```c
+cJSON* nostr_nip59_create_seal_with_signer(cJSON* rumor, nostr_signer_t* signer,
+                                           const unsigned char* recipient_public_key, long max_delay_sec);
+cJSON* nostr_nip59_unwrap_gift_with_signer(cJSON* gift_wrap, nostr_signer_t* signer);
+cJSON* nostr_nip59_unseal_rumor_with_signer(cJSON* seal, const unsigned char* sender_public_key,
+                                            nostr_signer_t* signer);
+```
+
+### Blossom client (`nostr_core/blossom_client.h`)
+
+```c
+char* blossom_create_auth_header_with_signer(nostr_signer_t* signer,
+                                             const char* operation,
+                                             const char* sha256_hex,
+                                             int expiration_seconds,
+                                             time_t timestamp);
+int blossom_upload_with_signer(const char* server_url,
+                               const unsigned char* data,
+                               size_t data_len,
+                               const char* content_type,
+                               nostr_signer_t* signer,
+                               const char* sha256_hex,
+                               int timeout_seconds,
+                               blossom_blob_descriptor_t* descriptor_out);
+int blossom_upload_file_with_signer(const char* server_url,
+                                    const char* file_path,
+                                    const char* content_type,
+                                    nostr_signer_t* signer,
+                                    int timeout_seconds,
+                                    blossom_blob_descriptor_t* descriptor_out);
+int blossom_delete_with_signer(const char* server_url,
+                               const char* sha256_hex,
+                               nostr_signer_t* signer,
+                               int timeout_seconds);
+```
+
+### Relay pool signer entry point (`nostr_core/nostr_core.h`)
+
+```c
+int nostr_relay_pool_set_auth_with_signer(nostr_relay_pool_t* pool, nostr_signer_t* signer, int enable);
+```
+
+## 5) Feasibility boundaries
+
+Remotable through `nostr_signer_t` / nsigner client contract:
+
+- Public key retrieval
+- Event signing
+- NIP-04 encrypt/decrypt
+- NIP-44 encrypt/decrypt
+
+Not generally remotable without protocol/API redesign:
+
+- Operations that require direct access to raw secret material for non-signer-verb cryptography.
+- In this codebase, Cashu mint-protocol-oriented pieces (e.g. in `cashu_mint`) are the identified example.
+
+## 6) Minimal C usage snippets
+
+### (a) Local signer create + sign + publish
+
+```c
+#include "nostr_core/nostr_core.h"
+
+int main(void) {
+    unsigned char privkey[32];
+    nostr_signer_t* signer;
+    cJSON* evt;
+    const char* relays[] = {"wss://relay.laantungir.net"};
+    int ok_count = 0;
+
+    if (nostr_init() != NOSTR_SUCCESS) return 1;
+
+    /* fill privkey via your key-management path */
+    signer = nostr_signer_local(privkey);
+    if (!signer) return 1;
+
+    evt = nostr_create_and_sign_event_with_signer(1, "hello", NULL, signer, time(NULL));
+    if (!evt) return 1;
+
+    publish_result_t* r = synchronous_publish_event_with_progress(
+        relays, 1, evt, &ok_count, 10, NULL, NULL, 0, NULL);
+
+    free(r);
+    cJSON_Delete(evt);
+    nostr_signer_free(signer);
+    nostr_cleanup();
+    return 0;
+}
+```
+
+### (b) Remote unix signer create + sign
+
+```c
+#include "nostr_core/nostr_core.h"
+
+int main(void) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (nostr_init() != NOSTR_SUCCESS) return 1;
+
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    signer = nostr_signer_nsigner_unix("nsigner-main", NULL, 15000);
+    if (!signer) return 1;
+
+    evt = nostr_create_and_sign_event_with_signer(1, "signed remotely", NULL, signer, time(NULL));
+    if (!evt) return 1;
+
+    cJSON_Delete(evt);
+    nostr_signer_free(signer);
+#endif
+
+    nostr_cleanup();
+    return 0;
+}
+```
+
+### (c) TCP signer + auth setup
+
+```c
+#include "nostr_core/nostr_core.h"
+
+int main(void) {
+    nostr_signer_t* signer;
+    unsigned char caller_auth_key[32];
+
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    signer = nostr_signer_nsigner_tcp("127.0.0.1", 7777, NULL, 15000);
+    if (!signer) return 1;
+
+    /* Required for TCP mode */
+    if (nostr_signer_nsigner_set_auth(signer, caller_auth_key, "my-caller") != NOSTR_SUCCESS) {
+        nostr_signer_free(signer);
+        return 1;
+    }
+
+    nostr_signer_free(signer);
+#endif
+
+    return 0;
+}
+```
+
+## 7) Build/flag wiring summary (exact current lines)
+
+### `build.sh`
+
+```bash
+SOURCES="$SOURCES nostr_core/nsigner_transport.c"
+SOURCES="$SOURCES nostr_core/nsigner_client.c"
+CFLAGS="$CFLAGS -DNOSTR_ENABLE_NSIGNER_CLIENT=1"
+```
+
+### `CMakeLists.txt`
+
+Desktop branch (`else()`):
+
+```cmake
+add_library(nostr_core STATIC
+    nostr_core/nostr_common.c
+    nostr_core/nostr_log.c
+    nostr_core/request_validator.c
+    nostr_core/nip001.c
+    nostr_core/nip006.c
+    nostr_core/nip019.c
+    nostr_core/nostr_signer.c
+    nostr_core/nsigner_transport.c
+    nostr_core/nsigner_client.c
+    nostr_core/utils.c
+    nostr_core/crypto/nostr_secp256k1.c
+    nostr_core/crypto/nostr_aes.c
+    nostr_core/crypto/nostr_chacha20.c
+    cjson/cJSON.c
+    platform/linux.c
+)
+
+target_compile_definitions(nostr_core PRIVATE NOSTR_ENABLE_NSIGNER_CLIENT=1)
+```
+
+ESP32 branch (`if(ESP_PLATFORM)`):
+
+- Does **not** include `nostr_core/nsigner_transport.c` or `nostr_core/nsigner_client.c` in `idf_component_register(SRCS ...)`.
+- Sets only:
+
+```cmake
+target_compile_definitions(${COMPONENT_LIB} PRIVATE NOSTR_NO_FILESYSTEM=1)
+```
+
+## 8) Testing pointers
+
+Relevant tests:
+
+- `tests/nsigner_client_test.c`
+- `tests/signer_modules_test.c`
+- `tests/nip01_test.c` (includes local-signer equivalence checks)
+
+Build tests:
+
+```bash
+./build.sh -t
+```
+
+Run target binaries:
+
+```bash
+./tests/nsigner_client_test
+./tests/signer_modules_test
+./tests/nip01_test
+```
+
+## 9) Driver app signer modes (`examples/note_poster.c`)
+
+Supported `--signer` values in the driver app:
+
+- `local` (default)
+- `unix:<name>`
+- `serial:<path>`
+- `tcp:<host>:<port>`
+- `fds:<read_fd>:<write_fd>`
+
+Examples:
+
+```bash
+./examples/note_poster
+./examples/note_poster --signer unix:<name>
+./examples/note_poster --signer serial:/dev/ttyACM0
+./examples/note_poster --signer tcp:<host>:<port>
+./examples/note_poster --signer fds:<read_fd>:<write_fd>
+```
+
+Local mode warning (from app behavior): this is test-key-only usage; do not use production keys.

nostr_core/blossom_client.c

@@ -0,0 +1,642 @@
+/*
+ * Blossom HTTP Client
+ */
+
+#include "blossom_client.h"
+
+#include "../cjson/cJSON.h"
+#include "nip001.h"
+#include "nostr_http.h"
+#include "utils.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+static int is_hex64_local(const char* s) {
+    if (!s || strlen(s) != 64) return 0;
+    for (int i = 0; i < 64; i++) {
+        char c = s[i];
+        if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'))) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+static void trim_trailing_slash_local(const char* in, char* out, size_t out_sz) {
+    if (!in || !out || out_sz == 0) return;
+    snprintf(out, out_sz, "%s", in);
+    size_t n = strlen(out);
+    while (n > 0 && out[n - 1] == '/') {
+        out[n - 1] = '\0';
+        n--;
+    }
+}
+
+static int build_blob_url_local(const char* server_url, const char* sha256_hex, char* out, size_t out_sz) {
+    if (!server_url || !sha256_hex || !out || out_sz == 0) return -1;
+    char base[512];
+    trim_trailing_slash_local(server_url, base, sizeof(base));
+    int n = snprintf(out, out_sz, "%s/%s", base, sha256_hex);
+    if (n < 0 || (size_t)n >= out_sz) return -1;
+    return 0;
+}
+
+static int parse_descriptor_local(const char* json_text, blossom_blob_descriptor_t* out) {
+    if (!json_text || !out) return NOSTR_ERROR_INVALID_INPUT;
+    cJSON* root = cJSON_Parse(json_text);
+    if (!root) return NOSTR_ERROR_IO_FAILED;
+
+    cJSON* sha = cJSON_GetObjectItemCaseSensitive(root, "sha256");
+    if (!sha) sha = cJSON_GetObjectItemCaseSensitive(root, "x");
+    cJSON* url = cJSON_GetObjectItemCaseSensitive(root, "url");
+    cJSON* size = cJSON_GetObjectItemCaseSensitive(root, "size");
+    cJSON* ct = cJSON_GetObjectItemCaseSensitive(root, "content_type");
+    if (!ct) ct = cJSON_GetObjectItemCaseSensitive(root, "m");
+    cJSON* created = cJSON_GetObjectItemCaseSensitive(root, "created");
+    if (!created) created = cJSON_GetObjectItemCaseSensitive(root, "created_at");
+
+    memset(out, 0, sizeof(*out));
+    if (sha && cJSON_IsString(sha) && sha->valuestring) {
+        snprintf(out->sha256, sizeof(out->sha256), "%s", sha->valuestring);
+    }
+    if (url && cJSON_IsString(url) && url->valuestring) {
+        snprintf(out->url, sizeof(out->url), "%s", url->valuestring);
+    }
+    if (size && cJSON_IsNumber(size)) out->size = (long)cJSON_GetNumberValue(size);
+    if (ct && cJSON_IsString(ct) && ct->valuestring) {
+        snprintf(out->content_type, sizeof(out->content_type), "%s", ct->valuestring);
+    }
+    if (created && cJSON_IsNumber(created)) out->created = (long)cJSON_GetNumberValue(created);
+
+    cJSON_Delete(root);
+    return NOSTR_SUCCESS;
+}
+
+void blossom_set_ca_bundle(const char* ca_bundle_path) {
+    nostr_http_set_ca_bundle(ca_bundle_path);
+}
+
+char* blossom_create_auth_header_with_signer(nostr_signer_t* signer,
+                                             const char* operation,
+                                             const char* sha256_hex,
+                                             int expiration_seconds,
+                                             time_t timestamp) {
+    if (!signer || !operation || operation[0] == '\0') return NULL;
+    if (sha256_hex && !is_hex64_local(sha256_hex)) return NULL;
+
+    cJSON* tags = cJSON_CreateArray();
+    if (!tags) return NULL;
+
+    cJSON* t_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(t_tag, cJSON_CreateString("t"));
+    cJSON_AddItemToArray(t_tag, cJSON_CreateString(operation));
+    cJSON_AddItemToArray(tags, t_tag);
+
+    if (sha256_hex) {
+        cJSON* x_tag = cJSON_CreateArray();
+        cJSON_AddItemToArray(x_tag, cJSON_CreateString("x"));
+        cJSON_AddItemToArray(x_tag, cJSON_CreateString(sha256_hex));
+        cJSON_AddItemToArray(tags, x_tag);
+    }
+
+    time_t now = (timestamp > 0) ? timestamp : time(NULL);
+    int exp = expiration_seconds > 0 ? expiration_seconds : 300;
+    long until = (long)now + exp;
+    char exp_buf[32];
+    snprintf(exp_buf, sizeof(exp_buf), "%ld", until);
+    cJSON* e_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(e_tag, cJSON_CreateString("expiration"));
+    cJSON_AddItemToArray(e_tag, cJSON_CreateString(exp_buf));
+    cJSON_AddItemToArray(tags, e_tag);
+
+    cJSON* evt = nostr_create_and_sign_event_with_signer(24242, "", tags, signer, now);
+    cJSON_Delete(tags);
+    if (!evt) return NULL;
+
+    char* evt_json = cJSON_PrintUnformatted(evt);
+    cJSON_Delete(evt);
+    if (!evt_json) return NULL;
+
+    size_t evt_len = strlen(evt_json);
+    size_t b64_cap = ((evt_len + 2U) / 3U) * 4U + 8U;
+    char* b64 = (char*)malloc(b64_cap);
+    if (!b64) {
+        free(evt_json);
+        return NULL;
+    }
+
+    size_t n = base64_encode((const unsigned char*)evt_json, evt_len, b64, b64_cap);
+    free(evt_json);
+    if (n == 0) {
+        free(b64);
+        return NULL;
+    }
+
+    size_t hdr_cap = n + 16U;
+    char* header = (char*)malloc(hdr_cap);
+    if (!header) {
+        free(b64);
+        return NULL;
+    }
+    snprintf(header, hdr_cap, "Nostr %s", b64);
+    free(b64);
+    return header;
+}
+
+char* blossom_create_auth_header(const unsigned char* private_key,
+                                 const char* operation,
+                                 const char* sha256_hex,
+                                 int expiration_seconds) {
+    if (!private_key || !operation || operation[0] == '\0') return NULL;
+    if (sha256_hex && !is_hex64_local(sha256_hex)) return NULL;
+
+    cJSON* tags = cJSON_CreateArray();
+    if (!tags) return NULL;
+
+    cJSON* t_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(t_tag, cJSON_CreateString("t"));
+    cJSON_AddItemToArray(t_tag, cJSON_CreateString(operation));
+    cJSON_AddItemToArray(tags, t_tag);
+
+    if (sha256_hex) {
+        cJSON* x_tag = cJSON_CreateArray();
+        cJSON_AddItemToArray(x_tag, cJSON_CreateString("x"));
+        cJSON_AddItemToArray(x_tag, cJSON_CreateString(sha256_hex));
+        cJSON_AddItemToArray(tags, x_tag);
+    }
+
+    int exp = expiration_seconds > 0 ? expiration_seconds : 300;
+    long now = (long)time(NULL);
+    long until = now + exp;
+    char exp_buf[32];
+    snprintf(exp_buf, sizeof(exp_buf), "%ld", until);
+    cJSON* e_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(e_tag, cJSON_CreateString("expiration"));
+    cJSON_AddItemToArray(e_tag, cJSON_CreateString(exp_buf));
+    cJSON_AddItemToArray(tags, e_tag);
+
+    cJSON* evt = nostr_create_and_sign_event(24242, "", tags, private_key, (time_t)now);
+    cJSON_Delete(tags);
+    if (!evt) return NULL;
+
+    char* evt_json = cJSON_PrintUnformatted(evt);
+    cJSON_Delete(evt);
+    if (!evt_json) return NULL;
+
+    size_t evt_len = strlen(evt_json);
+    size_t b64_cap = ((evt_len + 2U) / 3U) * 4U + 8U;
+    char* b64 = (char*)malloc(b64_cap);
+    if (!b64) {
+        free(evt_json);
+        return NULL;
+    }
+
+    size_t n = base64_encode((const unsigned char*)evt_json, evt_len, b64, b64_cap);
+    free(evt_json);
+    if (n == 0) {
+        free(b64);
+        return NULL;
+    }
+
+    size_t hdr_cap = n + 16U;
+    char* header = (char*)malloc(hdr_cap);
+    if (!header) {
+        free(b64);
+        return NULL;
+    }
+    snprintf(header, hdr_cap, "Nostr %s", b64);
+    free(b64);
+    return header;
+}
+
+int blossom_upload_with_signer(const char* server_url,
+                               const unsigned char* data,
+                               size_t data_len,
+                               const char* content_type,
+                               nostr_signer_t* signer,
+                               const char* sha256_hex,
+                               int timeout_seconds,
+                               blossom_blob_descriptor_t* descriptor_out) {
+    if (!server_url || !data || data_len == 0 || !descriptor_out) return NOSTR_ERROR_INVALID_INPUT;
+
+    char hash_hex[65] = {0};
+    if (sha256_hex) {
+        if (!is_hex64_local(sha256_hex)) return NOSTR_ERROR_INVALID_INPUT;
+        snprintf(hash_hex, sizeof(hash_hex), "%s", sha256_hex);
+    } else {
+        unsigned char hash[32];
+        if (nostr_sha256(data, data_len, hash) != 0) return NOSTR_ERROR_CRYPTO_FAILED;
+        nostr_bytes_to_hex(hash, 32, hash_hex);
+    }
+
+    char url[1024];
+    char base[512];
+    trim_trailing_slash_local(server_url, base, sizeof(base));
+    snprintf(url, sizeof(url), "%s/upload", base);
+
+    char auth_buf[1024] = {0};
+    char ctype_buf[256] = {0};
+    const char* headers[4] = {"Accept: application/json", NULL, NULL, NULL};
+    int h = 1;
+
+    if (content_type && content_type[0] != '\0') {
+        snprintf(ctype_buf, sizeof(ctype_buf), "Content-Type: %s", content_type);
+        headers[h++] = ctype_buf;
+    }
+
+    char* auth = NULL;
+    if (signer) {
+        auth = blossom_create_auth_header_with_signer(signer, "upload", hash_hex, 300, 0);
+        if (auth) {
+            snprintf(auth_buf, sizeof(auth_buf), "Authorization: %s", auth);
+            headers[h++] = auth_buf;
+        }
+    }
+    headers[h] = NULL;
+
+    nostr_http_request_t req;
+    memset(&req, 0, sizeof(req));
+    req.method = "PUT";
+    req.url = url;
+    req.headers = headers;
+    req.body = data;
+    req.body_len = data_len;
+    req.timeout_seconds = timeout_seconds > 0 ? timeout_seconds : 20;
+    req.follow_redirects = 1;
+    req.max_redirects = 3;
+
+    nostr_http_response_t resp;
+    int rc = nostr_http_request(&req, &resp);
+    free(auth);
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    if (resp.status_code < 200 || resp.status_code >= 300) {
+        nostr_http_response_free(&resp);
+        return NOSTR_ERROR_NETWORK_FAILED;
+    }
+
+    int prc = parse_descriptor_local(resp.body ? resp.body : "{}", descriptor_out);
+    if (prc != NOSTR_SUCCESS) {
+        memset(descriptor_out, 0, sizeof(*descriptor_out));
+        snprintf(descriptor_out->sha256, sizeof(descriptor_out->sha256), "%s", hash_hex);
+        descriptor_out->size = (long)data_len;
+        if (content_type && content_type[0] != '\0') {
+            snprintf(descriptor_out->content_type, sizeof(descriptor_out->content_type), "%s", content_type);
+        }
+    }
+
+    nostr_http_response_free(&resp);
+    return NOSTR_SUCCESS;
+}
+
+int blossom_upload(const char* server_url,
+                   const unsigned char* data,
+                   size_t data_len,
+                   const char* content_type,
+                   const unsigned char* private_key,
+                   const char* sha256_hex,
+                   int timeout_seconds,
+                   blossom_blob_descriptor_t* descriptor_out) {
+    nostr_signer_t* signer = NULL;
+    int rc;
+
+    if (private_key) {
+        signer = nostr_signer_local(private_key);
+    }
+
+    rc = blossom_upload_with_signer(server_url, data, data_len, content_type,
+                                    signer, sha256_hex, timeout_seconds, descriptor_out);
+    nostr_signer_free(signer);
+    return rc;
+}
+
+int blossom_upload_file_with_signer(const char* server_url,
+                                    const char* file_path,
+                                    const char* content_type,
+                                    nostr_signer_t* signer,
+                                    int timeout_seconds,
+                                    blossom_blob_descriptor_t* descriptor_out) {
+    if (!server_url || !file_path || !descriptor_out) return NOSTR_ERROR_INVALID_INPUT;
+
+    FILE* fp = fopen(file_path, "rb");
+    if (!fp) return NOSTR_ERROR_IO_FAILED;
+
+    if (fseek(fp, 0, SEEK_END) != 0) {
+        fclose(fp);
+        return NOSTR_ERROR_IO_FAILED;
+    }
+    long sz = ftell(fp);
+    if (sz < 0) {
+        fclose(fp);
+        return NOSTR_ERROR_IO_FAILED;
+    }
+    if (fseek(fp, 0, SEEK_SET) != 0) {
+        fclose(fp);
+        return NOSTR_ERROR_IO_FAILED;
+    }
+
+    unsigned char* buf = (unsigned char*)malloc((size_t)sz);
+    if (!buf) {
+        fclose(fp);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    size_t n = fread(buf, 1, (size_t)sz, fp);
+    fclose(fp);
+    if (n != (size_t)sz) {
+        free(buf);
+        return NOSTR_ERROR_IO_FAILED;
+    }
+
+    int rc = blossom_upload_with_signer(server_url, buf, n, content_type, signer, NULL, timeout_seconds, descriptor_out);
+    free(buf);
+    return rc;
+}
+
+int blossom_upload_file(const char* server_url,
+                        const char* file_path,
+                        const char* content_type,
+                        const unsigned char* private_key,
+                        int timeout_seconds,
+                        blossom_blob_descriptor_t* descriptor_out) {
+    nostr_signer_t* signer = NULL;
+    int rc;
+
+    if (private_key) {
+        signer = nostr_signer_local(private_key);
+    }
+
+    rc = blossom_upload_file_with_signer(server_url, file_path, content_type,
+                                         signer, timeout_seconds, descriptor_out);
+    nostr_signer_free(signer);
+    return rc;
+}
+
+int blossom_download(const char* server_url,
+                     const char* sha256_hex,
+                     int timeout_seconds,
+                     size_t max_bytes,
+                     unsigned char** body_out,
+                     size_t* body_len_out,
+                     char* content_type_out,
+                     size_t content_type_out_size) {
+    if (!server_url || !sha256_hex || !body_out || !body_len_out || !is_hex64_local(sha256_hex)) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *body_out = NULL;
+    *body_len_out = 0;
+    if (content_type_out && content_type_out_size > 0) content_type_out[0] = '\0';
+
+    char url[1024];
+    if (build_blob_url_local(server_url, sha256_hex, url, sizeof(url)) != 0) return NOSTR_ERROR_INVALID_INPUT;
+
+    nostr_http_request_t req;
+    memset(&req, 0, sizeof(req));
+    req.method = "GET";
+    req.url = url;
+    req.timeout_seconds = timeout_seconds > 0 ? timeout_seconds : 20;
+    req.max_response_bytes = max_bytes;
+    req.follow_redirects = 1;
+    req.max_redirects = 3;
+
+    nostr_http_response_t resp;
+    int rc = nostr_http_request(&req, &resp);
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    if (resp.status_code < 200 || resp.status_code >= 300) {
+        nostr_http_response_free(&resp);
+        return NOSTR_ERROR_NETWORK_FAILED;
+    }
+
+    unsigned char* out = (unsigned char*)malloc(resp.body_len > 0 ? resp.body_len : 1);
+    if (!out) {
+        nostr_http_response_free(&resp);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    if (resp.body_len > 0 && resp.body) memcpy(out, resp.body, resp.body_len);
+
+    *body_out = out;
+    *body_len_out = resp.body_len;
+    if (content_type_out && content_type_out_size > 0 && resp.content_type && resp.content_type[0] != '\0') {
+        snprintf(content_type_out, content_type_out_size, "%s", resp.content_type);
+    }
+
+    nostr_http_response_free(&resp);
+    return NOSTR_SUCCESS;
+}
+
+int blossom_download_to_file(const char* server_url,
+                             const char* sha256_hex,
+                             const char* output_path,
+                             int timeout_seconds,
+                             size_t max_bytes,
+                             blossom_blob_descriptor_t* descriptor_out) {
+    if (!server_url || !sha256_hex || !output_path || !descriptor_out) return NOSTR_ERROR_INVALID_INPUT;
+
+    unsigned char* body = NULL;
+    size_t body_len = 0;
+    char content_type[128] = {0};
+    int rc = blossom_download(server_url, sha256_hex, timeout_seconds, max_bytes, &body, &body_len, content_type, sizeof(content_type));
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    FILE* fp = fopen(output_path, "wb");
+    if (!fp) {
+        free(body);
+        return NOSTR_ERROR_IO_FAILED;
+    }
+    size_t wn = fwrite(body, 1, body_len, fp);
+    fclose(fp);
+    if (wn != body_len) {
+        free(body);
+        return NOSTR_ERROR_IO_FAILED;
+    }
+
+    unsigned char hash[32];
+    if (nostr_sha256(body, body_len, hash) != 0) {
+        free(body);
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+    free(body);
+
+    char hash_hex[65];
+    nostr_bytes_to_hex(hash, 32, hash_hex);
+
+    memset(descriptor_out, 0, sizeof(*descriptor_out));
+    snprintf(descriptor_out->sha256, sizeof(descriptor_out->sha256), "%s", hash_hex);
+    descriptor_out->size = (long)body_len;
+    if (content_type[0] != '\0') snprintf(descriptor_out->content_type, sizeof(descriptor_out->content_type), "%s", content_type);
+    build_blob_url_local(server_url, sha256_hex, descriptor_out->url, sizeof(descriptor_out->url));
+    return NOSTR_SUCCESS;
+}
+
+int blossom_head(const char* server_url,
+                 const char* sha256_hex,
+                 int timeout_seconds,
+                 blossom_blob_descriptor_t* descriptor_out) {
+    if (!server_url || !sha256_hex || !descriptor_out || !is_hex64_local(sha256_hex)) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    char url[1024];
+    if (build_blob_url_local(server_url, sha256_hex, url, sizeof(url)) != 0) return NOSTR_ERROR_INVALID_INPUT;
+
+    nostr_http_request_t req;
+    memset(&req, 0, sizeof(req));
+    req.method = "HEAD";
+    req.url = url;
+    req.timeout_seconds = timeout_seconds > 0 ? timeout_seconds : 10;
+    req.capture_headers = 1;
+
+    nostr_http_response_t resp;
+    int rc = nostr_http_request(&req, &resp);
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    if (resp.status_code < 200 || resp.status_code >= 300) {
+        nostr_http_response_free(&resp);
+        return NOSTR_ERROR_NETWORK_FAILED;
+    }
+
+    memset(descriptor_out, 0, sizeof(*descriptor_out));
+    snprintf(descriptor_out->sha256, sizeof(descriptor_out->sha256), "%s", sha256_hex);
+    if (build_blob_url_local(server_url, sha256_hex, descriptor_out->url, sizeof(descriptor_out->url)) != 0) {
+        nostr_http_response_free(&resp);
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+    if (resp.content_type && resp.content_type[0] != '\0') {
+        snprintf(descriptor_out->content_type, sizeof(descriptor_out->content_type), "%s", resp.content_type);
+    }
+
+    if (resp.headers_raw) {
+        const char* key = "Content-Length:";
+        char* p = strstr(resp.headers_raw, key);
+        if (p) {
+            p += strlen(key);
+            while (*p == ' ' || *p == '\t') p++;
+            descriptor_out->size = strtol(p, NULL, 10);
+        }
+    }
+
+    nostr_http_response_free(&resp);
+    return NOSTR_SUCCESS;
+}
+
+int blossom_delete_with_signer(const char* server_url,
+                               const char* sha256_hex,
+                               nostr_signer_t* signer,
+                               int timeout_seconds) {
+    if (!server_url || !sha256_hex || !signer || !is_hex64_local(sha256_hex)) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    char url[1024];
+    if (build_blob_url_local(server_url, sha256_hex, url, sizeof(url)) != 0) return NOSTR_ERROR_INVALID_INPUT;
+
+    char* auth = blossom_create_auth_header_with_signer(signer, "delete", sha256_hex, 300, 0);
+    if (!auth) return NOSTR_ERROR_CRYPTO_FAILED;
+
+    char auth_header[1200];
+    snprintf(auth_header, sizeof(auth_header), "Authorization: %s", auth);
+    free(auth);
+
+    const char* headers[] = {"Accept: application/json", auth_header, NULL};
+
+    nostr_http_request_t req;
+    memset(&req, 0, sizeof(req));
+    req.method = "DELETE";
+    req.url = url;
+    req.headers = headers;
+    req.timeout_seconds = timeout_seconds > 0 ? timeout_seconds : 20;
+
+    nostr_http_response_t resp;
+    int rc = nostr_http_request(&req, &resp);
+    if (rc != NOSTR_SUCCESS) return rc;
+    int ok = (resp.status_code >= 200 && resp.status_code < 300) ? NOSTR_SUCCESS : NOSTR_ERROR_NETWORK_FAILED;
+    nostr_http_response_free(&resp);
+    return ok;
+}
+
+int blossom_delete(const char* server_url,
+                   const char* sha256_hex,
+                   const unsigned char* private_key,
+                   int timeout_seconds) {
+    nostr_signer_t* signer;
+    int rc;
+
+    if (!private_key) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) {
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    rc = blossom_delete_with_signer(server_url, sha256_hex, signer, timeout_seconds);
+    nostr_signer_free(signer);
+    return rc;
+}
+
+int blossom_list(const char* server_url,
+                 const char* pubkey_hex,
+                 int timeout_seconds,
+                 blossom_blob_descriptor_t** descriptors_out,
+                 int* count_out) {
+    if (!server_url || !pubkey_hex || !descriptors_out || !count_out) return NOSTR_ERROR_INVALID_INPUT;
+
+    *descriptors_out = NULL;
+    *count_out = 0;
+
+    char base[512];
+    trim_trailing_slash_local(server_url, base, sizeof(base));
+    char url[1024];
+    snprintf(url, sizeof(url), "%s/list/%s", base, pubkey_hex);
+
+    nostr_http_request_t req;
+    memset(&req, 0, sizeof(req));
+    req.method = "GET";
+    req.url = url;
+    req.timeout_seconds = timeout_seconds > 0 ? timeout_seconds : 20;
+
+    nostr_http_response_t resp;
+    int rc = nostr_http_request(&req, &resp);
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    if (resp.status_code < 200 || resp.status_code >= 300) {
+        nostr_http_response_free(&resp);
+        return NOSTR_ERROR_NETWORK_FAILED;
+    }
+
+    cJSON* arr = cJSON_Parse(resp.body ? resp.body : "[]");
+    if (!arr || !cJSON_IsArray(arr)) {
+        cJSON_Delete(arr);
+        nostr_http_response_free(&resp);
+        return NOSTR_ERROR_IO_FAILED;
+    }
+
+    int n = cJSON_GetArraySize(arr);
+    blossom_blob_descriptor_t* out = (blossom_blob_descriptor_t*)calloc((size_t)n, sizeof(blossom_blob_descriptor_t));
+    if (!out && n > 0) {
+        cJSON_Delete(arr);
+        nostr_http_response_free(&resp);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    for (int i = 0; i < n; i++) {
+        cJSON* it = cJSON_GetArrayItem(arr, i);
+        char* tmp = cJSON_PrintUnformatted(it);
+        if (tmp) {
+            (void)parse_descriptor_local(tmp, &out[i]);
+            free(tmp);
+        }
+    }
+
+    *descriptors_out = out;
+    *count_out = n;
+
+    cJSON_Delete(arr);
+    nostr_http_response_free(&resp);
+    return NOSTR_SUCCESS;
+}

nostr_core/blossom_client.h

@@ -0,0 +1,111 @@
+/*
+ * Blossom HTTP Client
+ */
+
+#ifndef NOSTR_BLOSSOM_CLIENT_H
+#define NOSTR_BLOSSOM_CLIENT_H
+
+#include "nostr_common.h"
+#include "nostr_signer.h"
+#include <stddef.h>
+#include <time.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    char sha256[65];
+    char url[512];
+    long size;
+    char content_type[128];
+    long created;
+} blossom_blob_descriptor_t;
+
+void blossom_set_ca_bundle(const char* ca_bundle_path);
+
+char* blossom_create_auth_header(const unsigned char* private_key,
+                                 const char* operation,
+                                 const char* sha256_hex,
+                                 int expiration_seconds);
+
+char* blossom_create_auth_header_with_signer(nostr_signer_t* signer,
+                                             const char* operation,
+                                             const char* sha256_hex,
+                                             int expiration_seconds,
+                                             time_t timestamp);
+
+int blossom_upload(const char* server_url,
+                   const unsigned char* data,
+                   size_t data_len,
+                   const char* content_type,
+                   const unsigned char* private_key,
+                   const char* sha256_hex,
+                   int timeout_seconds,
+                   blossom_blob_descriptor_t* descriptor_out);
+
+int blossom_upload_with_signer(const char* server_url,
+                               const unsigned char* data,
+                               size_t data_len,
+                               const char* content_type,
+                               nostr_signer_t* signer,
+                               const char* sha256_hex,
+                               int timeout_seconds,
+                               blossom_blob_descriptor_t* descriptor_out);
+
+int blossom_upload_file(const char* server_url,
+                        const char* file_path,
+                        const char* content_type,
+                        const unsigned char* private_key,
+                        int timeout_seconds,
+                        blossom_blob_descriptor_t* descriptor_out);
+
+int blossom_upload_file_with_signer(const char* server_url,
+                                    const char* file_path,
+                                    const char* content_type,
+                                    nostr_signer_t* signer,
+                                    int timeout_seconds,
+                                    blossom_blob_descriptor_t* descriptor_out);
+
+int blossom_download(const char* server_url,
+                     const char* sha256_hex,
+                     int timeout_seconds,
+                     size_t max_bytes,
+                     unsigned char** body_out,
+                     size_t* body_len_out,
+                     char* content_type_out,
+                     size_t content_type_out_size);
+
+int blossom_download_to_file(const char* server_url,
+                             const char* sha256_hex,
+                             const char* output_path,
+                             int timeout_seconds,
+                             size_t max_bytes,
+                             blossom_blob_descriptor_t* descriptor_out);
+
+int blossom_head(const char* server_url,
+                 const char* sha256_hex,
+                 int timeout_seconds,
+                 blossom_blob_descriptor_t* descriptor_out);
+
+int blossom_delete(const char* server_url,
+                   const char* sha256_hex,
+                   const unsigned char* private_key,
+                   int timeout_seconds);
+
+int blossom_delete_with_signer(const char* server_url,
+                               const char* sha256_hex,
+                               nostr_signer_t* signer,
+                               int timeout_seconds);
+
+int blossom_list(const char* server_url,
+                 const char* pubkey_hex,
+                 int timeout_seconds,
+                 blossom_blob_descriptor_t** descriptors_out,
+                 int* count_out);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_BLOSSOM_CLIENT_H */

nostr_core/cashu_mint.h

@@ -0,0 +1,272 @@
+/*
+ * Cashu Mint HTTP Client
+ */
+
+#ifndef NOSTR_CASHU_MINT_H
+#define NOSTR_CASHU_MINT_H
+
+#include <stdint.h>
+#include <time.h>
+#include "nostr_common.h"
+#include "nip060.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define CASHU_API_VERSION "v1"
+
+typedef struct {
+    char id[NOSTR_CASHU_KEYSET_ID_HEX_SIZE];
+    char unit[16];
+    int active;
+} cashu_keyset_t;
+
+typedef enum {
+    CASHU_TOKEN_FORMAT_A = 0,
+    CASHU_TOKEN_FORMAT_B = 1
+} cashu_token_format_t;
+
+typedef struct {
+    uint64_t amount;
+    char pubkey[67];
+} cashu_amount_key_t;
+
+typedef struct {
+    char keyset_id[65];
+    char unit[16];
+    cashu_amount_key_t* keys;
+    int key_count;
+} cashu_keyset_keys_t;
+
+typedef struct {
+    char* name;
+    char* pubkey;
+    char* version;
+    cashu_keyset_t* keysets;
+    int keyset_count;
+} cashu_mint_info_t;
+
+typedef struct {
+    char quote_id[128];
+    char payment_request[2048];
+    int paid;
+    uint64_t amount;
+    time_t expiry;
+} cashu_mint_quote_t;
+
+typedef struct {
+    char quote_id[128];
+    uint64_t amount;
+    uint64_t fee_reserve;
+    int paid;
+    char* payment_preimage;
+    time_t expiry;
+} cashu_melt_quote_t;
+
+typedef struct {
+    char id[NOSTR_CASHU_KEYSET_ID_HEX_SIZE];
+    uint64_t amount;
+    char B_[256];
+} cashu_blinded_output_t;
+
+typedef struct {
+    char id[NOSTR_CASHU_KEYSET_ID_HEX_SIZE];
+    uint64_t amount;
+    char C_[256];
+} cashu_blinded_signature_t;
+
+typedef struct {
+    char quote_id[128];
+    char unit[16];
+    cashu_blinded_output_t* outputs;
+    int output_count;
+} cashu_mint_tokens_request_t;
+
+typedef struct {
+    cashu_blinded_signature_t* signatures;
+    int signature_count;
+} cashu_mint_tokens_response_t;
+
+typedef struct {
+    nostr_cashu_proof_t* inputs;
+    int input_count;
+    cashu_blinded_output_t* outputs;
+    int output_count;
+} cashu_swap_request_t;
+
+typedef struct {
+    cashu_blinded_signature_t* signatures;
+    int signature_count;
+} cashu_swap_response_t;
+
+typedef struct {
+    char quote_id[128];
+    nostr_cashu_proof_t* inputs;
+    int input_count;
+} cashu_melt_tokens_request_t;
+
+typedef struct {
+    int paid;
+    char* payment_preimage;
+    cJSON* change;
+} cashu_melt_tokens_response_t;
+
+typedef struct {
+    char Y[256];
+    char state[32];
+    char witness[512];
+} cashu_proof_state_t;
+
+typedef struct {
+    cashu_proof_state_t* states;
+    int state_count;
+} cashu_checkstate_response_t;
+
+typedef struct {
+    char* mint_url;
+    nostr_cashu_proof_t* proofs;
+    int proof_count;
+} cashu_decoded_token_t;
+
+void cashu_mint_set_ca_bundle(const char* ca_bundle_path);
+
+int cashu_mint_get_info(const char* mint_url,
+                        cashu_mint_info_t* info_out,
+                        int timeout_seconds);
+
+void cashu_mint_free_info(cashu_mint_info_t* info);
+
+int cashu_mint_get_keysets(const char* mint_url,
+                           cashu_keyset_t** keysets_out,
+                           int* keyset_count_out,
+                           int timeout_seconds);
+
+void cashu_mint_free_keysets(cashu_keyset_t* keysets);
+
+int cashu_mint_get_keys(const char* mint_url,
+                        const char* keyset_id,
+                        cashu_keyset_keys_t* keys_out,
+                        int timeout_seconds);
+
+void cashu_mint_free_keyset_keys(cashu_keyset_keys_t* keys);
+
+int cashu_keyset_keys_find_pubkey_for_amount(const cashu_keyset_keys_t* keys,
+                                             uint64_t amount,
+                                             const char** pubkey_out);
+
+int cashu_mint_request_mint_quote(const char* mint_url,
+                                  uint64_t amount,
+                                  const char* unit,
+                                  cashu_mint_quote_t* quote_out,
+                                  int timeout_seconds);
+
+int cashu_mint_check_mint_quote(const char* mint_url,
+                                const char* quote_id,
+                                cashu_mint_quote_t* quote_out,
+                                int timeout_seconds);
+
+int cashu_mint_request_melt_quote(const char* mint_url,
+                                  const char* payment_request,
+                                  const char* unit,
+                                  cashu_melt_quote_t* quote_out,
+                                  int timeout_seconds);
+
+int cashu_mint_check_melt_quote(const char* mint_url,
+                                const char* quote_id,
+                                cashu_melt_quote_t* quote_out,
+                                int timeout_seconds);
+
+int cashu_mint_swap(const char* mint_url,
+                    cJSON* request_body,
+                    cJSON** response_out,
+                    int timeout_seconds);
+
+int cashu_mint_mint_tokens(const char* mint_url,
+                           cJSON* request_body,
+                           cJSON** response_out,
+                           int timeout_seconds);
+
+int cashu_mint_melt_tokens(const char* mint_url,
+                           cJSON* request_body,
+                           cJSON** response_out,
+                           int timeout_seconds);
+
+int cashu_mint_check_proofs_state(const char* mint_url,
+                                  cJSON* request_body,
+                                  cJSON** response_out,
+                                  int timeout_seconds);
+
+int cashu_mint_get_active_keyset(const cashu_mint_info_t* info,
+                                 const char* optional_unit,
+                                 cashu_keyset_t* keyset_out);
+
+int cashu_mint_select_proofs_for_amount(const nostr_cashu_proof_t* proofs,
+                                        int proof_count,
+                                        uint64_t target_amount,
+                                        int* selected_indices_out,
+                                        int selected_indices_cap,
+                                        uint64_t* selected_total_out);
+
+int cashu_mint_plan_split_amounts(uint64_t amount,
+                                  uint64_t* amounts_out,
+                                  int max_amounts,
+                                  int* amount_count_out);
+
+int cashu_build_mint_tokens_request(const cashu_mint_tokens_request_t* req,
+                                    cJSON** request_body_out);
+
+int cashu_parse_mint_tokens_response(cJSON* response_body,
+                                     cashu_mint_tokens_response_t* response_out);
+
+void cashu_mint_free_mint_tokens_response(cashu_mint_tokens_response_t* response);
+
+int cashu_build_swap_request(const cashu_swap_request_t* req,
+                             cJSON** request_body_out);
+
+int cashu_parse_swap_response(cJSON* response_body,
+                              cashu_swap_response_t* response_out);
+
+void cashu_mint_free_swap_response(cashu_swap_response_t* response);
+
+int cashu_build_melt_tokens_request(const cashu_melt_tokens_request_t* req,
+                                    cJSON** request_body_out);
+
+int cashu_parse_melt_tokens_response(cJSON* response_body,
+                                     cashu_melt_tokens_response_t* response_out);
+
+void cashu_mint_free_melt_tokens_response(cashu_melt_tokens_response_t* response);
+
+int cashu_build_checkstate_request(const char** Ys,
+                                   int y_count,
+                                   cJSON** request_body_out);
+
+int cashu_parse_checkstate_response(cJSON* response_body,
+                                    cashu_checkstate_response_t* response_out);
+
+void cashu_mint_free_checkstate_response(cashu_checkstate_response_t* response);
+
+int cashu_decode_token(const char* token_string,
+                       cashu_decoded_token_t* token_out);
+
+int cashu_encode_token(const cashu_decoded_token_t* token,
+                       cashu_token_format_t format,
+                       char** token_string_out);
+
+void cashu_free_decoded_token(cashu_decoded_token_t* token);
+
+int cashu_blind_message(const char* secret,
+                        const char* mint_pubkey_hex,
+                        char out_B_hex[67],
+                        unsigned char out_r[32]);
+
+int cashu_unblind_signature(const char* C_blinded_hex,
+                            const char* mint_pubkey_hex,
+                            const unsigned char r[32],
+                            char out_C_hex[67]);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_CASHU_MINT_H */

nostr_core/core_relays.c

@@ -13,7 +13,7 @@
 #define _GNU_SOURCE
 #define _POSIX_C_SOURCE 200809L
 
-#include "nostr_common.h"
+#include "nostr_core.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -26,6 +26,9 @@
 // cJSON for JSON handling
 #include "../cjson/cJSON.h"
 
+// NIP-42 Authentication
+#include "nip042.h"
+
 // =============================================================================
 // TYPE DEFINITIONS FOR SYNCHRONOUS RELAY QUERIES
 // =============================================================================
@@ -51,6 +54,12 @@ typedef struct {
     cJSON** events;              // Array of events from this relay
     int events_capacity;         // Allocated capacity
     char subscription_id[32];    // Unique subscription ID
+
+    // NIP-42 Authentication fields
+    nostr_auth_state_t auth_state;           // Current authentication state
+    char auth_challenge[NOSTR_NIP42_MAX_CHALLENGE_LENGTH]; // Stored challenge
+    time_t auth_challenge_time;              // When challenge was received
+    int nip42_enabled;                       // Whether NIP-42 is enabled for this relay
 } relay_connection_t;
 
 
@@ -65,7 +74,9 @@ cJSON** synchronous_query_relays_with_progress(
     int* result_count,
     int relay_timeout_seconds,
     relay_progress_callback_t callback,
-    void* user_data) {
+    void* user_data,
+    int nip42_enabled,
+    const unsigned char* private_key) {
     
     if (!relay_urls || relay_count <= 0 || !filter || !result_count) {
         if (result_count) *result_count = 0;
@@ -95,11 +106,17 @@ cJSON** synchronous_query_relays_with_progress(
         relays[i].last_activity = start_time;
         relays[i].events_capacity = 10;
         relays[i].events = malloc(relays[i].events_capacity * sizeof(cJSON*));
-        
+
+        // Initialize NIP-42 authentication fields
+        relays[i].auth_state = NOSTR_AUTH_STATE_NONE;
+        memset(relays[i].auth_challenge, 0, sizeof(relays[i].auth_challenge));
+        relays[i].auth_challenge_time = 0;
+        relays[i].nip42_enabled = nip42_enabled;
+
         // Generate unique subscription ID
-        snprintf(relays[i].subscription_id, sizeof(relays[i].subscription_id), 
+        snprintf(relays[i].subscription_id, sizeof(relays[i].subscription_id),
                  "sync_%d_%ld", i, start_time);
-        
+
         if (callback) {
             callback(relays[i].url, "connecting", NULL, 0, relay_count, 0, user_data);
         }
@@ -178,9 +195,10 @@ cJSON** synchronous_query_relays_with_progress(
                 continue;
             }
             
-            // Try to receive message (short timeout to keep UI responsive)
-            char buffer[8192];
-            int len = nostr_ws_receive(relay->client, buffer, sizeof(buffer)-1, 50);
+            // Try to receive message (1000ms timeout to allow relay time
+            // to respond — matches nostr_relay_pool_query_sync behavior)
+            char buffer[262144];
+            int len = nostr_ws_receive(relay->client, buffer, sizeof(buffer)-1, 1000);
             
             if (len > 0) {
                 buffer[len] = '\0';
@@ -191,19 +209,50 @@ cJSON** synchronous_query_relays_with_progress(
                 cJSON* parsed = NULL;
                 if (nostr_parse_relay_message(buffer, &msg_type, &parsed) == 0) {
                     
-                    if (msg_type && strcmp(msg_type, "EVENT") == 0) {
+                    if (msg_type && strcmp(msg_type, "AUTH") == 0) {
+                        // Handle AUTH challenge message: ["AUTH", <challenge-string>]
+                        if (relay->nip42_enabled && private_key && cJSON_IsArray(parsed) && cJSON_GetArraySize(parsed) >= 2) {
+                            cJSON* challenge_json = cJSON_GetArrayItem(parsed, 1);
+                            if (cJSON_IsString(challenge_json)) {
+                                const char* challenge = cJSON_GetStringValue(challenge_json);
+
+                                // Store challenge and attempt authentication
+                                strncpy(relay->auth_challenge, challenge, sizeof(relay->auth_challenge) - 1);
+                                relay->auth_challenge[sizeof(relay->auth_challenge) - 1] = '\0';
+                                relay->auth_challenge_time = time(NULL);
+                                relay->auth_state = NOSTR_AUTH_STATE_CHALLENGE_RECEIVED;
+
+                                // Create and send authentication event
+                                cJSON* auth_event = nostr_nip42_create_auth_event(challenge, relay->url, private_key, 0);
+                                if (auth_event) {
+                                    char* auth_message = nostr_nip42_create_auth_message(auth_event);
+                                    if (auth_message) {
+                                        if (nostr_ws_send_text(relay->client, auth_message) >= 0) {
+                                            relay->auth_state = NOSTR_AUTH_STATE_AUTHENTICATING;
+                                            if (callback) {
+                                                callback(relay->url, "authenticating", NULL, 0, relay_count, completed_relays, user_data);
+                                            }
+                                        }
+                                        free(auth_message);
+                                    }
+                                    cJSON_Delete(auth_event);
+                                }
+                            }
+                        }
+
+                    } else if (msg_type && strcmp(msg_type, "EVENT") == 0) {
                         // Handle EVENT message
                         if (cJSON_IsArray(parsed) && cJSON_GetArraySize(parsed) >= 3) {
                             cJSON* sub_id_json = cJSON_GetArrayItem(parsed, 1);
                             cJSON* event = cJSON_GetArrayItem(parsed, 2);
-                            
+
                             if (cJSON_IsString(sub_id_json) && event &&
                                 strcmp(cJSON_GetStringValue(sub_id_json), relay->subscription_id) == 0) {
-                                
+
                                 cJSON* event_id_json = cJSON_GetObjectItem(event, "id");
                                 if (event_id_json && cJSON_IsString(event_id_json)) {
                                     const char* event_id = cJSON_GetStringValue(event_id_json);
-                                    
+
                                     // Check for duplicate
                                     int is_duplicate = 0;
                                     for (int j = 0; j < seen_count; j++) {
@@ -212,31 +261,31 @@ cJSON** synchronous_query_relays_with_progress(
                                             break;
                                         }
                                     }
-                                    
+
                                     if (!is_duplicate && seen_count < 1000) {
                                         // New event - add to seen list
                                         strncpy(seen_event_ids[seen_count], event_id, 64);
                                         seen_event_ids[seen_count][64] = '\0';
                                         seen_count++;
                                         total_unique_events++;
-                                        
+
                                         // Store event in relay's array
                                         if (relay->events_received >= relay->events_capacity) {
                                             relay->events_capacity *= 2;
-                                            relay->events = realloc(relay->events, 
+                                            relay->events = realloc(relay->events,
                                                 relay->events_capacity * sizeof(cJSON*));
                                         }
-                                        
+
                                         relay->events[relay->events_received] = cJSON_Duplicate(event, 1);
                                         relay->events_received++;
                                         relay->state = RELAY_STATE_ACTIVE;
-                                        
+
                                         if (callback) {
-                                            callback(relay->url, "event_found", event_id, 
-                                                    relay->events_received, relay_count, 
+                                            callback(relay->url, "event_found", event_id,
+                                                    relay->events_received, relay_count,
                                                     completed_relays, user_data);
                                         }
-                                        
+
                                         // For FIRST_RESULT mode, return immediately
                                         if (mode == RELAY_QUERY_FIRST_RESULT) {
                                             result_array = malloc(sizeof(cJSON*));
@@ -244,7 +293,7 @@ cJSON** synchronous_query_relays_with_progress(
                                                 result_array[0] = cJSON_Duplicate(event, 1);
                                                 *result_count = 1;
                                                 if (callback) {
-                                                    callback(NULL, "first_result", event_id, 
+                                                    callback(NULL, "first_result", event_id,
                                                             1, relay_count, completed_relays, user_data);
                                                 }
                                             }
@@ -254,7 +303,7 @@ cJSON** synchronous_query_relays_with_progress(
                                 }
                             }
                         }
-                        
+
                     } else if (msg_type && strcmp(msg_type, "EOSE") == 0) {
                         // Handle End of Stored Events
                         cJSON* sub_id_json = cJSON_GetArrayItem(parsed, 1);
@@ -274,6 +323,23 @@ cJSON** synchronous_query_relays_with_progress(
                             nostr_ws_close(relay->client);
                             relay->client = NULL;
                         }
+                    } else if (msg_type && (strcmp(msg_type, "NOTICE") == 0 ||
+                                             strcmp(msg_type, "CLOSED") == 0)) {
+                        /* Capture NOTICE and CLOSED messages from the relay.
+                         * These often contain auth-required or restriction
+                         * notices. Pass the message content to the callback. */
+                        const char* notice_msg = "";
+                        if (cJSON_IsArray(parsed) && cJSON_GetArraySize(parsed) >= 2) {
+                            cJSON* msg_json = cJSON_GetArrayItem(parsed, 1);
+                            if (msg_json && cJSON_IsString(msg_json)) {
+                                notice_msg = cJSON_GetStringValue(msg_json);
+                            }
+                        }
+                        if (callback) {
+                            callback(relay->url, msg_type, notice_msg,
+                                    relay->events_received, relay_count,
+                                    completed_relays, user_data);
+                        }
                     }
                     
                     if (msg_type) free(msg_type);
@@ -400,7 +466,9 @@ publish_result_t* synchronous_publish_event_with_progress(
     int* success_count,
     int relay_timeout_seconds,
     publish_progress_callback_t callback,
-    void* user_data) {
+    void* user_data,
+    int nip42_enabled,
+    const unsigned char* private_key) {
     
     if (!relay_urls || relay_count <= 0 || !event || !success_count) {
         if (success_count) *success_count = 0;
@@ -443,7 +511,13 @@ publish_result_t* synchronous_publish_event_with_progress(
         relays[i].state = RELAY_STATE_CONNECTING;
         relays[i].last_activity = start_time;
         results[i] = PUBLISH_ERROR; // Default to error
-        
+
+        // Initialize NIP-42 authentication fields
+        relays[i].auth_state = NOSTR_AUTH_STATE_NONE;
+        memset(relays[i].auth_challenge, 0, sizeof(relays[i].auth_challenge));
+        relays[i].auth_challenge_time = 0;
+        relays[i].nip42_enabled = nip42_enabled;
+
         if (callback) {
             callback(relays[i].url, "connecting", NULL, 0, relay_count, 0, user_data);
         }
@@ -524,7 +598,7 @@ publish_result_t* synchronous_publish_event_with_progress(
             }
             
             // Try to receive message (short timeout to keep UI responsive)
-            char buffer[8192];
+            char buffer[262144];
             int len = nostr_ws_receive(relay->client, buffer, sizeof(buffer)-1, 50);
             
             if (len > 0) {
@@ -535,34 +609,65 @@ publish_result_t* synchronous_publish_event_with_progress(
                 char* msg_type = NULL;
                 cJSON* parsed = NULL;
                 if (nostr_parse_relay_message(buffer, &msg_type, &parsed) == 0) {
-                    
-                    if (msg_type && strcmp(msg_type, "OK") == 0) {
+
+                    if (msg_type && strcmp(msg_type, "AUTH") == 0) {
+                        // Handle AUTH challenge message: ["AUTH", <challenge-string>]
+                        if (relay->nip42_enabled && private_key && cJSON_IsArray(parsed) && cJSON_GetArraySize(parsed) >= 2) {
+                            cJSON* challenge_json = cJSON_GetArrayItem(parsed, 1);
+                            if (cJSON_IsString(challenge_json)) {
+                                const char* challenge = cJSON_GetStringValue(challenge_json);
+
+                                // Store challenge and attempt authentication
+                                strncpy(relay->auth_challenge, challenge, sizeof(relay->auth_challenge) - 1);
+                                relay->auth_challenge[sizeof(relay->auth_challenge) - 1] = '\0';
+                                relay->auth_challenge_time = time(NULL);
+                                relay->auth_state = NOSTR_AUTH_STATE_CHALLENGE_RECEIVED;
+
+                                // Create and send authentication event
+                                cJSON* auth_event = nostr_nip42_create_auth_event(challenge, relay->url, private_key, 0);
+                                if (auth_event) {
+                                    char* auth_message = nostr_nip42_create_auth_message(auth_event);
+                                    if (auth_message) {
+                                        if (nostr_ws_send_text(relay->client, auth_message) >= 0) {
+                                            relay->auth_state = NOSTR_AUTH_STATE_AUTHENTICATING;
+                                            if (callback) {
+                                                callback(relay->url, "authenticating", NULL, 0, relay_count, completed_relays, user_data);
+                                            }
+                                        }
+                                        free(auth_message);
+                                    }
+                                    cJSON_Delete(auth_event);
+                                }
+                            }
+                        }
+
+                    } else if (msg_type && strcmp(msg_type, "OK") == 0) {
                         // Handle OK message: ["OK", <event_id>, <true|false>, <message>]
                         if (cJSON_IsArray(parsed) && cJSON_GetArraySize(parsed) >= 3) {
                             cJSON* ok_event_id = cJSON_GetArrayItem(parsed, 1);
                             cJSON* accepted = cJSON_GetArrayItem(parsed, 2);
                             cJSON* message = cJSON_GetArrayItem(parsed, 3);
-                            
+
                             // Verify this OK is for our event
                             if (ok_event_id && cJSON_IsString(ok_event_id) && event_id &&
                                 strcmp(cJSON_GetStringValue(ok_event_id), event_id) == 0) {
-                                
+
                                 relay->state = RELAY_STATE_EOSE_RECEIVED; // Reuse for "completed"
                                 active_relays--;
                                 completed_relays++;
-                                
+
                                 const char* ok_message = "";
                                 if (message && cJSON_IsString(message)) {
                                     ok_message = cJSON_GetStringValue(message);
                                 }
-                                
+
                                 if (accepted && cJSON_IsBool(accepted) && cJSON_IsTrue(accepted)) {
                                     // Event accepted
                                     results[i] = PUBLISH_SUCCESS;
                                     (*success_count)++;
                                     
                                     if (callback) {
-                                        callback(relay->url, "accepted", ok_message, 
+                                        callback(relay->url, "accepted", ok_message,
                                                 *success_count, relay_count, completed_relays, user_data);
                                     }
                                 } else {
@@ -570,11 +675,11 @@ publish_result_t* synchronous_publish_event_with_progress(
                                     results[i] = PUBLISH_REJECTED;
                                     
                                     if (callback) {
-                                        callback(relay->url, "rejected", ok_message, 
+                                        callback(relay->url, "rejected", ok_message,
                                                 *success_count, relay_count, completed_relays, user_data);
                                     }
                                 }
-                                
+
                                 // Close connection
                                 nostr_ws_close(relay->client);
                                 relay->client = NULL;

nostr_core/crypto/nostr_aes.c

@@ -1,15 +1,76 @@
 /*
  * NOSTR AES Implementation
- * 
+ *
  * Based on tiny-AES-c by kokke (public domain)
  * Configured specifically for NIP-04: AES-256-CBC only
- * 
+ *
  * This is an implementation of the AES algorithm, specifically CBC mode.
  * Configured for AES-256 as required by NIP-04.
  */
 
+#include <stdint.h>
+#include <stddef.h>
 #include <string.h> // CBC mode, for memset
-#include "nostr_aes.h"
+
+// Configure for NIP-04 requirements: AES-256-CBC only
+#define CBC 1
+#define ECB 0
+#define CTR 0
+
+// Configure for AES-256 (required by NIP-04)
+#define AES128 0
+#define AES192 0
+#define AES256 1
+
+#define AES_BLOCKLEN 16 // Block length in bytes - AES is 128b block only
+
+#if defined(AES256) && (AES256 == 1)
+    #define AES_KEYLEN 32
+    #define AES_keyExpSize 240
+#elif defined(AES192) && (AES192 == 1)
+    #define AES_KEYLEN 24
+    #define AES_keyExpSize 208
+#else
+    #define AES_KEYLEN 16   // Key length in bytes
+    #define AES_keyExpSize 176
+#endif
+
+struct AES_ctx
+{
+  uint8_t RoundKey[AES_keyExpSize];
+#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
+  uint8_t Iv[AES_BLOCKLEN];
+#endif
+};
+
+// state - array holding the intermediate results during decryption.
+typedef uint8_t state_t[4][4];
+
+// Function prototypes (internal use only)
+static void KeyExpansion(uint8_t* RoundKey, const uint8_t* Key);
+static void AddRoundKey(uint8_t round, state_t* state, const uint8_t* RoundKey);
+static void SubBytes(state_t* state);
+static void ShiftRows(state_t* state);
+static uint8_t xtime(uint8_t x);
+static void MixColumns(state_t* state);
+static void InvMixColumns(state_t* state);
+static void InvSubBytes(state_t* state);
+static void InvShiftRows(state_t* state);
+static void Cipher(state_t* state, const uint8_t* RoundKey);
+static void InvCipher(state_t* state, const uint8_t* RoundKey);
+static void XorWithIv(uint8_t* buf, const uint8_t* Iv);
+
+// Public functions (used by NIP-04 implementation)
+void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key);
+#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
+void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv);
+void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
+#endif
+
+#if defined(CBC) && (CBC == 1)
+void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
+void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
+#endif
 
 // The number of columns comprising a state in AES. This is a constant in AES. Value=4
 #define Nb 4

nostr_core/crypto/nostr_aes.h

@@ -1,53 +0,0 @@
-#ifndef _NOSTR_AES_H_
-#define _NOSTR_AES_H_
-
-#include <stdint.h>
-#include <stddef.h>
-
-// Configure for NIP-04 requirements: AES-256-CBC only
-#define CBC 1
-#define ECB 0
-#define CTR 0
-
-// Configure for AES-256 (required by NIP-04)
-#define AES128 0
-#define AES192 0
-#define AES256 1
-
-#define AES_BLOCKLEN 16 // Block length in bytes - AES is 128b block only
-
-#if defined(AES256) && (AES256 == 1)
-    #define AES_KEYLEN 32
-    #define AES_keyExpSize 240
-#elif defined(AES192) && (AES192 == 1)
-    #define AES_KEYLEN 24
-    #define AES_keyExpSize 208
-#else
-    #define AES_KEYLEN 16   // Key length in bytes
-    #define AES_keyExpSize 176
-#endif
-
-struct AES_ctx
-{
-  uint8_t RoundKey[AES_keyExpSize];
-#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
-  uint8_t Iv[AES_BLOCKLEN];
-#endif
-};
-
-void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key);
-#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
-void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv);
-void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
-#endif
-
-#if defined(CBC) && (CBC == 1)
-// buffer size MUST be multiple of AES_BLOCKLEN;
-// Suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
-// NOTES: you need to set IV in ctx via AES_init_ctx_iv() or AES_ctx_set_iv()
-//        no IV should ever be reused with the same key 
-void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
-void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
-#endif // #if defined(CBC) && (CBC == 1)
-
-#endif // _NOSTR_AES_H_

nostr_core/crypto/nostr_chacha20.c

@@ -1,15 +1,47 @@
 /*
  * nostr_chacha20.c - ChaCha20 stream cipher implementation
- * 
+ *
  * Implementation based on RFC 8439 "ChaCha20 and Poly1305 for IETF Protocols"
- * 
+ *
  * This implementation is adapted from the RFC 8439 reference specification.
  * It prioritizes correctness and clarity over performance optimization.
  */
 
-#include "nostr_chacha20.h"
+#include <stdint.h>
+#include <stddef.h>
 #include <string.h>
 
+/*
+ * ============================================================================
+ * CONSTANTS AND DEFINITIONS
+ * ============================================================================
+ */
+
+#define CHACHA20_KEY_SIZE    32  /* 256 bits */
+#define CHACHA20_NONCE_SIZE  12  /* 96 bits */
+#define CHACHA20_BLOCK_SIZE  64  /* 512 bits */
+
+/*
+ * ============================================================================
+ * FUNCTION PROTOTYPES (INTERNAL USE ONLY)
+ * ============================================================================
+ */
+
+// Internal utility functions
+static uint32_t bytes_to_u32_le(const uint8_t *bytes);
+static void u32_to_bytes_le(uint32_t val, uint8_t *bytes);
+
+// Public functions (used by NIP-44 implementation)
+void chacha20_quarter_round(uint32_t state[16], int a, int b, int c, int d);
+int chacha20_block(const uint8_t key[32], uint32_t counter,
+                   const uint8_t nonce[12], uint8_t output[64]);
+int chacha20_encrypt(const uint8_t key[32], uint32_t counter,
+                     const uint8_t nonce[12], const uint8_t* input,
+                     uint8_t* output, size_t length);
+void chacha20_init_state(uint32_t state[16], const uint8_t key[32],
+                         uint32_t counter, const uint8_t nonce[12]);
+void chacha20_serialize_state(const uint32_t state[16], uint8_t output[64]);
+
 /*
  * ============================================================================
  * UTILITY MACROS AND FUNCTIONS

nostr_core/crypto/nostr_chacha20.h

@@ -1,115 +0,0 @@
-/*
- * nostr_chacha20.h - ChaCha20 stream cipher implementation
- * 
- * Implementation based on RFC 8439 "ChaCha20 and Poly1305 for IETF Protocols"
- * 
- * This is a small, portable implementation for NIP-44 support in the NOSTR library.
- * The implementation prioritizes correctness and simplicity over performance.
- */
-
-#ifndef NOSTR_CHACHA20_H
-#define NOSTR_CHACHA20_H
-
-#include <stdint.h>
-#include <stddef.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/*
- * ============================================================================
- * CONSTANTS AND DEFINITIONS
- * ============================================================================
- */
-
-#define CHACHA20_KEY_SIZE    32  /* 256 bits */
-#define CHACHA20_NONCE_SIZE  12  /* 96 bits */
-#define CHACHA20_BLOCK_SIZE  64  /* 512 bits */
-
-/*
- * ============================================================================
- * CORE CHACHA20 FUNCTIONS
- * ============================================================================
- */
-
-/**
- * ChaCha20 quarter round operation
- * 
- * Operates on four 32-bit words performing the core ChaCha20 quarter round:
- * a += b; d ^= a; d <<<= 16;
- * c += d; b ^= c; b <<<= 12;
- * a += b; d ^= a; d <<<= 8;
- * c += d; b ^= c; b <<<= 7;
- * 
- * @param state[in,out] ChaCha state as 16 32-bit words
- * @param a, b, c, d    Indices into state array for quarter round
- */
-void chacha20_quarter_round(uint32_t state[16], int a, int b, int c, int d);
-
-/**
- * ChaCha20 block function
- * 
- * Transforms a 64-byte input block using ChaCha20 algorithm with 20 rounds.
- * 
- * @param key[in]       32-byte key
- * @param counter[in]   32-bit block counter
- * @param nonce[in]     12-byte nonce
- * @param output[out]   64-byte output buffer
- * @return              0 on success, negative on error
- */
-int chacha20_block(const uint8_t key[32], uint32_t counter, 
-                   const uint8_t nonce[12], uint8_t output[64]);
-
-/**
- * ChaCha20 encryption/decryption
- * 
- * Encrypts or decrypts data using ChaCha20 stream cipher.
- * Since ChaCha20 is a stream cipher, encryption and decryption are the same operation.
- * 
- * @param key[in]           32-byte key
- * @param counter[in]       Initial 32-bit counter value
- * @param nonce[in]         12-byte nonce
- * @param input[in]         Input data to encrypt/decrypt
- * @param output[out]       Output buffer (can be same as input)
- * @param length[in]        Length of input data in bytes
- * @return                  0 on success, negative on error
- */
-int chacha20_encrypt(const uint8_t key[32], uint32_t counter, 
-                     const uint8_t nonce[12], const uint8_t* input, 
-                     uint8_t* output, size_t length);
-
-/*
- * ============================================================================
- * UTILITY FUNCTIONS
- * ============================================================================
- */
-
-/**
- * Initialize ChaCha20 state matrix
- * 
- * Sets up the initial 16-word state matrix with constants, key, counter, and nonce.
- * 
- * @param state[out]    16-word state array to initialize
- * @param key[in]       32-byte key
- * @param counter[in]   32-bit block counter
- * @param nonce[in]     12-byte nonce
- */
-void chacha20_init_state(uint32_t state[16], const uint8_t key[32], 
-                         uint32_t counter, const uint8_t nonce[12]);
-
-/**
- * Serialize ChaCha20 state to bytes
- * 
- * Converts 16 32-bit words to 64 bytes in little-endian format.
- * 
- * @param state[in]     16-word state array
- * @param output[out]   64-byte output buffer
- */
-void chacha20_serialize_state(const uint32_t state[16], uint8_t output[64]);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* NOSTR_CHACHA20_H */

nostr_core/crypto/nostr_chacha20poly1305.c

@@ -0,0 +1,192 @@
+/*
+ * nostr_chacha20poly1305.c - ChaCha20-Poly1305 AEAD implementation
+ *
+ * RFC 8439 Section 2.8
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+// ChaCha20 private API (provided by nostr_chacha20.c)
+int chacha20_block(const uint8_t key[32], uint32_t counter,
+                   const uint8_t nonce[12], uint8_t output[64]);
+int chacha20_encrypt(const uint8_t key[32], uint32_t counter,
+                     const uint8_t nonce[12], const uint8_t* input,
+                     uint8_t* output, size_t length);
+
+// Poly1305 API (provided by nostr_poly1305.c)
+int nostr_poly1305_mac(const unsigned char key[32], const unsigned char *msg,
+                       size_t msg_len, unsigned char tag[16]);
+
+static void store64_le(unsigned char out[8], uint64_t v) {
+    out[0] = (unsigned char)(v & 0xff);
+    out[1] = (unsigned char)((v >> 8) & 0xff);
+    out[2] = (unsigned char)((v >> 16) & 0xff);
+    out[3] = (unsigned char)((v >> 24) & 0xff);
+    out[4] = (unsigned char)((v >> 32) & 0xff);
+    out[5] = (unsigned char)((v >> 40) & 0xff);
+    out[6] = (unsigned char)((v >> 48) & 0xff);
+    out[7] = (unsigned char)((v >> 56) & 0xff);
+}
+
+static int constant_time_tag_eq(const unsigned char a[16], const unsigned char b[16]) {
+    unsigned char diff = 0;
+    size_t i;
+    for (i = 0; i < 16; i++) {
+        diff |= (unsigned char)(a[i] ^ b[i]);
+    }
+    return diff == 0;
+}
+
+static int build_poly1305_input(const unsigned char *aad, size_t aad_len,
+                                const unsigned char *ciphertext, size_t ct_len,
+                                unsigned char **out, size_t *out_len) {
+    size_t aad_pad = (16 - (aad_len % 16)) % 16;
+    size_t ct_pad = (16 - (ct_len % 16)) % 16;
+    size_t total = aad_len + aad_pad + ct_len + ct_pad + 16; // len(aad)||len(ct)
+    unsigned char *buf;
+    size_t pos = 0;
+    unsigned char len_block[16];
+
+    if (!out || !out_len) {
+        return -1;
+    }
+
+    buf = (unsigned char *)malloc(total);
+    if (!buf) {
+        return -1;
+    }
+
+    if (aad_len > 0 && aad) {
+        memcpy(buf + pos, aad, aad_len);
+        pos += aad_len;
+    }
+    if (aad_pad > 0) {
+        memset(buf + pos, 0, aad_pad);
+        pos += aad_pad;
+    }
+
+    if (ct_len > 0 && ciphertext) {
+        memcpy(buf + pos, ciphertext, ct_len);
+        pos += ct_len;
+    }
+    if (ct_pad > 0) {
+        memset(buf + pos, 0, ct_pad);
+        pos += ct_pad;
+    }
+
+    store64_le(len_block, (uint64_t)aad_len);
+    store64_le(len_block + 8, (uint64_t)ct_len);
+    memcpy(buf + pos, len_block, sizeof(len_block));
+    pos += sizeof(len_block);
+
+    *out = buf;
+    *out_len = pos;
+    return 0;
+}
+
+int nostr_chacha20poly1305_encrypt(const unsigned char key[32],
+                                   const unsigned char nonce[12],
+                                   const unsigned char *aad, size_t aad_len,
+                                   const unsigned char *plaintext, size_t pt_len,
+                                   unsigned char *ciphertext,
+                                   unsigned char tag[16]) {
+    unsigned char block0[64];
+    unsigned char poly_key[32];
+    unsigned char *poly_in = NULL;
+    size_t poly_in_len = 0;
+    int rc;
+
+    if (!key || !nonce || !ciphertext || !tag || (!plaintext && pt_len != 0) || (!aad && aad_len != 0)) {
+        return -1;
+    }
+
+    if (chacha20_block(key, 0, nonce, block0) != 0) {
+        return -1;
+    }
+    memcpy(poly_key, block0, sizeof(poly_key));
+
+    if (pt_len > 0) {
+        rc = chacha20_encrypt(key, 1, nonce, plaintext, ciphertext, pt_len);
+        if (rc != 0) {
+            memset(poly_key, 0, sizeof(poly_key));
+            return -1;
+        }
+    }
+
+    rc = build_poly1305_input(aad, aad_len, ciphertext, pt_len, &poly_in, &poly_in_len);
+    if (rc != 0) {
+        memset(poly_key, 0, sizeof(poly_key));
+        return -1;
+    }
+
+    rc = nostr_poly1305_mac(poly_key, poly_in, poly_in_len, tag);
+
+    memset(poly_key, 0, sizeof(poly_key));
+    memset(block0, 0, sizeof(block0));
+    memset(poly_in, 0, poly_in_len);
+    free(poly_in);
+
+    return rc;
+}
+
+int nostr_chacha20poly1305_decrypt(const unsigned char key[32],
+                                   const unsigned char nonce[12],
+                                   const unsigned char *aad, size_t aad_len,
+                                   const unsigned char *ciphertext, size_t ct_len,
+                                   const unsigned char tag[16],
+                                   unsigned char *plaintext) {
+    unsigned char block0[64];
+    unsigned char poly_key[32];
+    unsigned char expected_tag[16];
+    unsigned char *poly_in = NULL;
+    size_t poly_in_len = 0;
+    int rc;
+
+    if (!key || !nonce || !tag || !plaintext || (!ciphertext && ct_len != 0) || (!aad && aad_len != 0)) {
+        return -1;
+    }
+
+    if (chacha20_block(key, 0, nonce, block0) != 0) {
+        return -1;
+    }
+    memcpy(poly_key, block0, sizeof(poly_key));
+
+    rc = build_poly1305_input(aad, aad_len, ciphertext, ct_len, &poly_in, &poly_in_len);
+    if (rc != 0) {
+        memset(poly_key, 0, sizeof(poly_key));
+        return -1;
+    }
+
+    rc = nostr_poly1305_mac(poly_key, poly_in, poly_in_len, expected_tag);
+    if (rc != 0 || !constant_time_tag_eq(tag, expected_tag)) {
+        memset(poly_key, 0, sizeof(poly_key));
+        memset(block0, 0, sizeof(block0));
+        memset(expected_tag, 0, sizeof(expected_tag));
+        memset(poly_in, 0, poly_in_len);
+        free(poly_in);
+        return -1;
+    }
+
+    if (ct_len > 0) {
+        rc = chacha20_encrypt(key, 1, nonce, ciphertext, plaintext, ct_len);
+        if (rc != 0) {
+            memset(poly_key, 0, sizeof(poly_key));
+            memset(block0, 0, sizeof(block0));
+            memset(expected_tag, 0, sizeof(expected_tag));
+            memset(poly_in, 0, poly_in_len);
+            free(poly_in);
+            return -1;
+        }
+    }
+
+    memset(poly_key, 0, sizeof(poly_key));
+    memset(block0, 0, sizeof(block0));
+    memset(expected_tag, 0, sizeof(expected_tag));
+    memset(poly_in, 0, poly_in_len);
+    free(poly_in);
+
+    return 0;
+}

nostr_core/crypto/nostr_poly1305.c

@@ -0,0 +1,262 @@
+/*
+ * nostr_poly1305.c - Poly1305 message authentication code
+ *
+ * Public-domain style 32-bit implementation based on the poly1305-donna
+ * approach, adapted for nostr_core_lib naming and conventions.
+ *
+ * RFC 8439 Section 2.5
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+typedef struct {
+    uint32_t r0, r1, r2, r3, r4;
+    uint32_t s1, s2, s3, s4;
+    uint32_t h0, h1, h2, h3, h4;
+    uint32_t pad0, pad1, pad2, pad3;
+    size_t leftover;
+    unsigned char buffer[16];
+    unsigned char final;
+} nostr_poly1305_ctx_t;
+
+static uint32_t u8to32_le(const unsigned char *p) {
+    return ((uint32_t)p[0]) |
+           ((uint32_t)p[1] << 8) |
+           ((uint32_t)p[2] << 16) |
+           ((uint32_t)p[3] << 24);
+}
+
+static void u32to8_le(unsigned char *p, uint32_t v) {
+    p[0] = (unsigned char)(v & 0xff);
+    p[1] = (unsigned char)((v >> 8) & 0xff);
+    p[2] = (unsigned char)((v >> 16) & 0xff);
+    p[3] = (unsigned char)((v >> 24) & 0xff);
+}
+
+static void poly1305_blocks(nostr_poly1305_ctx_t *st, const unsigned char *m, size_t bytes) {
+    const uint32_t r0 = st->r0;
+    const uint32_t r1 = st->r1;
+    const uint32_t r2 = st->r2;
+    const uint32_t r3 = st->r3;
+    const uint32_t r4 = st->r4;
+    const uint32_t s1 = st->s1;
+    const uint32_t s2 = st->s2;
+    const uint32_t s3 = st->s3;
+    const uint32_t s4 = st->s4;
+    uint32_t h0 = st->h0;
+    uint32_t h1 = st->h1;
+    uint32_t h2 = st->h2;
+    uint32_t h3 = st->h3;
+    uint32_t h4 = st->h4;
+    const uint32_t hibit = st->final ? 0 : (1U << 24);
+
+    while (bytes >= 16) {
+        uint32_t t0 = u8to32_le(m + 0);
+        uint32_t t1 = u8to32_le(m + 4);
+        uint32_t t2 = u8to32_le(m + 8);
+        uint32_t t3 = u8to32_le(m + 12);
+
+        uint64_t d0, d1, d2, d3, d4;
+        uint32_t c;
+
+        h0 += ( t0                    ) & 0x3ffffff;
+        h1 += (((t1 << 6) | (t0 >> 26)) ) & 0x3ffffff;
+        h2 += (((t2 << 12) | (t1 >> 20))) & 0x3ffffff;
+        h3 += (((t3 << 18) | (t2 >> 14))) & 0x3ffffff;
+        h4 += (( t3 >> 8)               ) & 0x00ffffff;
+        h4 += hibit;
+
+        d0 = ((uint64_t)h0 * r0) + ((uint64_t)h1 * s4) + ((uint64_t)h2 * s3) + ((uint64_t)h3 * s2) + ((uint64_t)h4 * s1);
+        d1 = ((uint64_t)h0 * r1) + ((uint64_t)h1 * r0) + ((uint64_t)h2 * s4) + ((uint64_t)h3 * s3) + ((uint64_t)h4 * s2);
+        d2 = ((uint64_t)h0 * r2) + ((uint64_t)h1 * r1) + ((uint64_t)h2 * r0) + ((uint64_t)h3 * s4) + ((uint64_t)h4 * s3);
+        d3 = ((uint64_t)h0 * r3) + ((uint64_t)h1 * r2) + ((uint64_t)h2 * r1) + ((uint64_t)h3 * r0) + ((uint64_t)h4 * s4);
+        d4 = ((uint64_t)h0 * r4) + ((uint64_t)h1 * r3) + ((uint64_t)h2 * r2) + ((uint64_t)h3 * r1) + ((uint64_t)h4 * r0);
+
+        c = (uint32_t)(d0 >> 26); h0 = (uint32_t)d0 & 0x3ffffff;
+        d1 += c;
+        c = (uint32_t)(d1 >> 26); h1 = (uint32_t)d1 & 0x3ffffff;
+        d2 += c;
+        c = (uint32_t)(d2 >> 26); h2 = (uint32_t)d2 & 0x3ffffff;
+        d3 += c;
+        c = (uint32_t)(d3 >> 26); h3 = (uint32_t)d3 & 0x3ffffff;
+        d4 += c;
+        c = (uint32_t)(d4 >> 26); h4 = (uint32_t)d4 & 0x3ffffff;
+        h0 += c * 5;
+        c = h0 >> 26; h0 &= 0x3ffffff;
+        h1 += c;
+
+        m += 16;
+        bytes -= 16;
+    }
+
+    st->h0 = h0;
+    st->h1 = h1;
+    st->h2 = h2;
+    st->h3 = h3;
+    st->h4 = h4;
+}
+
+void nostr_poly1305_init(nostr_poly1305_ctx_t *st, const unsigned char key[32]) {
+    uint32_t t0, t1, t2, t3;
+
+    t0 = u8to32_le(key + 0);
+    t1 = u8to32_le(key + 4);
+    t2 = u8to32_le(key + 8);
+    t3 = u8to32_le(key + 12);
+
+    st->r0 = ( t0                    ) & 0x3ffffff;
+    st->r1 = (((t1 << 6) | (t0 >> 26)) ) & 0x3ffff03;
+    st->r2 = (((t2 << 12) | (t1 >> 20))) & 0x3ffc0ff;
+    st->r3 = (((t3 << 18) | (t2 >> 14))) & 0x3f03fff;
+    st->r4 = (( t3 >> 8)               ) & 0x00fffff;
+
+    st->s1 = st->r1 * 5;
+    st->s2 = st->r2 * 5;
+    st->s3 = st->r3 * 5;
+    st->s4 = st->r4 * 5;
+
+    st->h0 = 0;
+    st->h1 = 0;
+    st->h2 = 0;
+    st->h3 = 0;
+    st->h4 = 0;
+
+    st->pad0 = u8to32_le(key + 16);
+    st->pad1 = u8to32_le(key + 20);
+    st->pad2 = u8to32_le(key + 24);
+    st->pad3 = u8to32_le(key + 28);
+
+    st->leftover = 0;
+    st->final = 0;
+}
+
+void nostr_poly1305_update(nostr_poly1305_ctx_t *st, const unsigned char *m, size_t bytes) {
+    size_t i;
+
+    if (st->leftover) {
+        size_t want = (size_t)(16 - st->leftover);
+        if (want > bytes) {
+            want = bytes;
+        }
+        for (i = 0; i < want; i++) {
+            st->buffer[st->leftover + i] = m[i];
+        }
+        bytes -= want;
+        m += want;
+        st->leftover += want;
+        if (st->leftover < 16) {
+            return;
+        }
+        poly1305_blocks(st, st->buffer, 16);
+        st->leftover = 0;
+    }
+
+    if (bytes >= 16) {
+        size_t want = bytes & ~(size_t)0xf;
+        poly1305_blocks(st, m, want);
+        m += want;
+        bytes -= want;
+    }
+
+    if (bytes) {
+        for (i = 0; i < bytes; i++) {
+            st->buffer[st->leftover + i] = m[i];
+        }
+        st->leftover += bytes;
+    }
+}
+
+void nostr_poly1305_final(nostr_poly1305_ctx_t *st, unsigned char tag[16]) {
+    uint32_t h0, h1, h2, h3, h4, c;
+    uint32_t g0, g1, g2, g3, g4;
+    uint64_t f;
+    uint32_t mask;
+
+    if (st->leftover) {
+        size_t i = st->leftover;
+        st->buffer[i++] = 1;
+        for (; i < 16; i++) {
+            st->buffer[i] = 0;
+        }
+        st->final = 1;
+        poly1305_blocks(st, st->buffer, 16);
+    }
+
+    h0 = st->h0;
+    h1 = st->h1;
+    h2 = st->h2;
+    h3 = st->h3;
+    h4 = st->h4;
+
+    c = h1 >> 26; h1 &= 0x3ffffff;
+    h2 += c;
+    c = h2 >> 26; h2 &= 0x3ffffff;
+    h3 += c;
+    c = h3 >> 26; h3 &= 0x3ffffff;
+    h4 += c;
+    c = h4 >> 26; h4 &= 0x3ffffff;
+    h0 += c * 5;
+    c = h0 >> 26; h0 &= 0x3ffffff;
+    h1 += c;
+
+    g0 = h0 + 5;
+    c = g0 >> 26; g0 &= 0x3ffffff;
+    g1 = h1 + c;
+    c = g1 >> 26; g1 &= 0x3ffffff;
+    g2 = h2 + c;
+    c = g2 >> 26; g2 &= 0x3ffffff;
+    g3 = h3 + c;
+    c = g3 >> 26; g3 &= 0x3ffffff;
+    g4 = h4 + c - (1U << 26);
+
+    mask = (g4 >> 31) - 1U;
+    g0 &= mask;
+    g1 &= mask;
+    g2 &= mask;
+    g3 &= mask;
+    g4 &= mask;
+    mask = ~mask;
+    h0 = (h0 & mask) | g0;
+    h1 = (h1 & mask) | g1;
+    h2 = (h2 & mask) | g2;
+    h3 = (h3 & mask) | g3;
+    h4 = (h4 & mask) | g4;
+
+    h0 = ((h0      ) | (h1 << 26)) & 0xffffffff;
+    h1 = ((h1 >> 6 ) | (h2 << 20)) & 0xffffffff;
+    h2 = ((h2 >> 12) | (h3 << 14)) & 0xffffffff;
+    h3 = ((h3 >> 18) | (h4 << 8 )) & 0xffffffff;
+
+    f = (uint64_t)h0 + st->pad0;
+    h0 = (uint32_t)f;
+    f = (uint64_t)h1 + st->pad1 + (f >> 32);
+    h1 = (uint32_t)f;
+    f = (uint64_t)h2 + st->pad2 + (f >> 32);
+    h2 = (uint32_t)f;
+    f = (uint64_t)h3 + st->pad3 + (f >> 32);
+    h3 = (uint32_t)f;
+
+    u32to8_le(tag + 0, h0);
+    u32to8_le(tag + 4, h1);
+    u32to8_le(tag + 8, h2);
+    u32to8_le(tag + 12, h3);
+
+    memset(st, 0, sizeof(*st));
+}
+
+int nostr_poly1305_mac(const unsigned char key[32], const unsigned char *msg,
+                       size_t msg_len, unsigned char tag[16]) {
+    nostr_poly1305_ctx_t ctx;
+
+    if (!key || (!msg && msg_len != 0) || !tag) {
+        return -1;
+    }
+
+    nostr_poly1305_init(&ctx, key);
+    nostr_poly1305_update(&ctx, msg, msg_len);
+    nostr_poly1305_final(&ctx, tag);
+
+    return 0;
+}

nostr_core/crypto/nostr_secp256k1.c

@@ -1,11 +1,36 @@
-#include "nostr_secp256k1.h"
 #include <secp256k1.h>
 #include <secp256k1_schnorrsig.h>
 #include <secp256k1_ecdh.h>
 #include <string.h>
 #include <stdlib.h>
-#include <fcntl.h>
-#include <unistd.h>
+#include <stddef.h>
+#include "../nostr_platform.h"
+
+/*
+ * PRIVATE INTERNAL FUNCTIONS - NOT EXPORTED
+ * These functions are for internal library use only.
+ */
+
+/** Opaque data structure that holds a parsed and valid public key.
+ *  Guaranteed to be 64 bytes in size, and can be safely copied/moved.
+ */
+typedef struct nostr_secp256k1_pubkey {
+    unsigned char data[64];
+} nostr_secp256k1_pubkey;
+
+/** Opaque data structure that holds a parsed keypair.
+ *  Guaranteed to be 96 bytes in size, and can be safely copied/moved.
+ */
+typedef struct nostr_secp256k1_keypair {
+    unsigned char data[96];
+} nostr_secp256k1_keypair;
+
+/** Opaque data structure that holds a parsed x-only public key.
+ *  Guaranteed to be 64 bytes in size, and can be safely copied/moved.
+ */
+typedef struct nostr_secp256k1_xonly_pubkey {
+    unsigned char data[64];
+} nostr_secp256k1_xonly_pubkey;
 
 // Global context for secp256k1 operations
 static secp256k1_context* g_ctx = NULL;
@@ -211,28 +236,85 @@ int nostr_secp256k1_ecdh(unsigned char *result, const nostr_secp256k1_pubkey *pu
     return secp256k1_ecdh(g_ctx, result, &internal_pubkey, seckey, hashfp, data);
 }
 
+int nostr_secp256k1_ec_pubkey_tweak_mul(nostr_secp256k1_pubkey* pubkey, const unsigned char* tweak32) {
+    if (g_ctx == NULL || pubkey == NULL || tweak32 == NULL) {
+        return 0;
+    }
+
+    secp256k1_pubkey internal_pubkey;
+    memcpy(&internal_pubkey, pubkey->data, sizeof(secp256k1_pubkey));
+
+    if (!secp256k1_ec_pubkey_tweak_mul(g_ctx, &internal_pubkey, tweak32)) {
+        return 0;
+    }
+
+    memcpy(pubkey->data, &internal_pubkey, sizeof(secp256k1_pubkey));
+    return 1;
+}
+
+int nostr_secp256k1_ec_pubkey_negate(nostr_secp256k1_pubkey* pubkey) {
+    if (g_ctx == NULL || pubkey == NULL) {
+        return 0;
+    }
+
+    secp256k1_pubkey internal_pubkey;
+    memcpy(&internal_pubkey, pubkey->data, sizeof(secp256k1_pubkey));
+
+    if (!secp256k1_ec_pubkey_negate(g_ctx, &internal_pubkey)) {
+        return 0;
+    }
+
+    memcpy(pubkey->data, &internal_pubkey, sizeof(secp256k1_pubkey));
+    return 1;
+}
+
+int nostr_secp256k1_ec_pubkey_combine(nostr_secp256k1_pubkey* out,
+                                      const nostr_secp256k1_pubkey* const* ins,
+                                      size_t n) {
+    if (g_ctx == NULL || out == NULL || ins == NULL || n == 0) {
+        return 0;
+    }
+
+    secp256k1_pubkey* parsed = (secp256k1_pubkey*)calloc(n, sizeof(secp256k1_pubkey));
+    const secp256k1_pubkey** ptrs = (const secp256k1_pubkey**)calloc(n, sizeof(secp256k1_pubkey*));
+    if (!parsed || !ptrs) {
+        free(parsed);
+        free(ptrs);
+        return 0;
+    }
+
+    for (size_t i = 0; i < n; i++) {
+        if (!ins[i]) {
+            free(parsed);
+            free(ptrs);
+            return 0;
+        }
+        memcpy(&parsed[i], ins[i]->data, sizeof(secp256k1_pubkey));
+        ptrs[i] = &parsed[i];
+    }
+
+    secp256k1_pubkey combined;
+    int ok = secp256k1_ec_pubkey_combine(g_ctx, &combined, ptrs, n);
+
+    free(parsed);
+    free(ptrs);
+
+    if (!ok) {
+        return 0;
+    }
+
+    memcpy(out->data, &combined, sizeof(secp256k1_pubkey));
+    return 1;
+}
+
 int nostr_secp256k1_get_random_bytes(unsigned char *buf, size_t len) {
     if (buf == NULL || len == 0) {
         return 0;
     }
     
-    // Try to use /dev/urandom for good randomness
-    int fd = open("/dev/urandom", O_RDONLY);
-    if (fd >= 0) {
-        ssize_t result = read(fd, buf, len);
-        close(fd);
-        if (result == (ssize_t)len) {
-            return 1;
-        }
+    if (nostr_platform_random(buf, len) != 0) {
+        return 0;
     }
-    
-    // Fallback to a simple PRNG (not cryptographically secure, but better than nothing)
-    // In a real implementation, you'd want to use a proper CSPRNG
-    static unsigned long seed = 1;
-    for (size_t i = 0; i < len; i++) {
-        seed = seed * 1103515245 + 12345;
-        buf[i] = (unsigned char)(seed >> 16);
-    }
-    
+
     return 1;
 }

nostr_core/crypto/nostr_secp256k1.h

@@ -1,141 +0,0 @@
-#ifndef NOSTR_SECP256K1_H
-#define NOSTR_SECP256K1_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#include <stddef.h>
-
-/** Opaque data structure that holds a parsed and valid public key.
- *  Guaranteed to be 64 bytes in size, and can be safely copied/moved.
- */
-typedef struct nostr_secp256k1_pubkey {
-    unsigned char data[64];
-} nostr_secp256k1_pubkey;
-
-/** Opaque data structure that holds a parsed keypair.
- *  Guaranteed to be 96 bytes in size, and can be safely copied/moved.
- */
-typedef struct nostr_secp256k1_keypair {
-    unsigned char data[96];
-} nostr_secp256k1_keypair;
-
-/** Opaque data structure that holds a parsed x-only public key.
- *  Guaranteed to be 64 bytes in size, and can be safely copied/moved.
- */
-typedef struct nostr_secp256k1_xonly_pubkey {
-    unsigned char data[64];
-} nostr_secp256k1_xonly_pubkey;
-
-/** Initialize the secp256k1 library. Must be called before any other functions.
- *  Returns: 1 on success, 0 on failure.
- */
-int nostr_secp256k1_context_create(void);
-
-/** Clean up the secp256k1 library resources.
- */
-void nostr_secp256k1_context_destroy(void);
-
-/** Verify an elliptic curve secret key.
- *  Returns: 1: secret key is valid, 0: secret key is invalid
- *  In: seckey: pointer to a 32-byte secret key.
- */
-int nostr_secp256k1_ec_seckey_verify(const unsigned char *seckey);
-
-/** Compute the public key for a secret key.
- *  Returns: 1: secret was valid, public key stored. 0: secret was invalid.
- *  Out: pubkey: pointer to the created public key.
- *  In:  seckey: pointer to a 32-byte secret key.
- */
-int nostr_secp256k1_ec_pubkey_create(nostr_secp256k1_pubkey *pubkey, const unsigned char *seckey);
-
-/** Create a keypair from a secret key.
- *  Returns: 1: keypair created, 0: secret key invalid.
- *  Out: keypair: pointer to the created keypair.
- *  In:  seckey:  pointer to a 32-byte secret key.
- */
-int nostr_secp256k1_keypair_create(nostr_secp256k1_keypair *keypair, const unsigned char *seckey);
-
-/** Get the x-only public key from a keypair.
- *  Returns: 1 always.
- *  Out: pubkey: pointer to storage for the x-only public key.
- *  In:  keypair: pointer to a keypair.
- */
-int nostr_secp256k1_keypair_xonly_pub(nostr_secp256k1_xonly_pubkey *pubkey, const nostr_secp256k1_keypair *keypair);
-
-/** Parse an x-only public key from bytes.
- *  Returns: 1: public key parsed, 0: invalid public key.
- *  Out: pubkey: pointer to the created x-only public key.
- *  In:  input32: pointer to a 32-byte x-only public key.
- */
-int nostr_secp256k1_xonly_pubkey_parse(nostr_secp256k1_xonly_pubkey *pubkey, const unsigned char *input32);
-
-/** Serialize an x-only public key to bytes.
- *  Returns: 1 always.
- *  Out: output32: pointer to a 32-byte array to store the serialized key.
- *  In:  pubkey:   pointer to an x-only public key.
- */
-int nostr_secp256k1_xonly_pubkey_serialize(unsigned char *output32, const nostr_secp256k1_xonly_pubkey *pubkey);
-
-/** Create a Schnorr signature.
- *  Returns: 1: signature created, 0: nonce generation failed or secret key invalid.
- *  Out: sig64:     pointer to a 64-byte array where the signature will be placed.
- *  In:  msghash32: the 32-byte message hash being signed.
- *       keypair:   pointer to an initialized keypair.
- *       aux_rand32: pointer to 32 bytes of auxiliary randomness (can be NULL).
- */
-int nostr_secp256k1_schnorrsig_sign32(unsigned char *sig64, const unsigned char *msghash32, const nostr_secp256k1_keypair *keypair, const unsigned char *aux_rand32);
-
-/** Verify a Schnorr signature.
- *  Returns: 1: correct signature, 0: incorrect signature
- *  In: sig64:     pointer to the 64-byte signature being verified.
- *      msghash32: the 32-byte message hash being verified.
- *      pubkey:    pointer to an x-only public key to verify with.
- */
-int nostr_secp256k1_schnorrsig_verify(const unsigned char *sig64, const unsigned char *msghash32, const nostr_secp256k1_xonly_pubkey *pubkey);
-
-/** Serialize a pubkey object into a serialized byte sequence.
- *  Returns: 1 always.
- *  Out: output:     pointer to a 33-byte array to place the serialized key in.
- *  In:  pubkey:     pointer to a secp256k1_pubkey containing an initialized public key.
- *
- *  The output will be a 33-byte compressed public key (0x02 or 0x03 prefix + 32 bytes x coordinate).
- */
-int nostr_secp256k1_ec_pubkey_serialize_compressed(unsigned char *output, const nostr_secp256k1_pubkey *pubkey);
-
-/** Tweak a secret key by adding a 32-byte tweak to it.
- *  Returns: 1: seckey was valid, 0: seckey invalid or resulting key invalid
- *  In/Out: seckey: pointer to a 32-byte secret key. Will be modified in-place.
- *  In:     tweak:  pointer to a 32-byte tweak.
- */
-int nostr_secp256k1_ec_seckey_tweak_add(unsigned char *seckey, const unsigned char *tweak);
-
-/** Parse a variable-length public key into the pubkey object.
- *  Returns: 1: public key parsed, 0: invalid public key.
- *  Out: pubkey: pointer to the created public key.
- *  In:  input:  pointer to a serialized public key
- *       inputlen: length of the array pointed to by input
- */
-int nostr_secp256k1_ec_pubkey_parse(nostr_secp256k1_pubkey *pubkey, const unsigned char *input, size_t inputlen);
-
-/** Compute an EC Diffie-Hellman secret in constant time.
- *  Returns: 1: exponentiation was successful, 0: scalar was invalid (zero or overflow)
- *  Out: result: a 32-byte array which will be populated by an ECDH secret computed from point and scalar
- *  In:  pubkey: a pointer to a secp256k1_pubkey containing an initialized public key
- *       seckey: a 32-byte scalar with which to multiply the point
- */
-int nostr_secp256k1_ecdh(unsigned char *result, const nostr_secp256k1_pubkey *pubkey, const unsigned char *seckey, void *hashfp, void *data);
-
-/** Generate cryptographically secure random bytes.
- *  Returns: 1: success, 0: failure
- *  Out: buf: buffer to fill with random bytes
- *  In:  len: number of bytes to generate
- */
-int nostr_secp256k1_get_random_bytes(unsigned char *buf, size_t len);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* NOSTR_SECP256K1_H */

nostr_core/nip001.c

@@ -7,81 +7,216 @@
 #include "nip001.h"
 #include "utils.h"
 #include "../cjson/cJSON.h"
+#include "nostr_signer.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include "../nostr_core/nostr_common.h"
 
+// Forward declarations for crypto functions (private API)
+// These functions are implemented in crypto/ but not exposed through public headers
+typedef struct {
+    unsigned char data[64];
+} nostr_secp256k1_xonly_pubkey;
+
+int nostr_secp256k1_xonly_pubkey_parse(nostr_secp256k1_xonly_pubkey* pubkey, const unsigned char* input32);
+int nostr_secp256k1_schnorrsig_verify(const unsigned char* sig64, const unsigned char* msg32, const nostr_secp256k1_xonly_pubkey* pubkey);
+
 // Declare utility functions
 void nostr_bytes_to_hex(const unsigned char* bytes, size_t len, char* hex);
 int nostr_hex_to_bytes(const char* hex, unsigned char* bytes, size_t len);
+int nostr_sha256(const unsigned char* data, size_t len, unsigned char* hash);
+int nostr_ec_public_key_from_private_key(const unsigned char* private_key, unsigned char* public_key);
+int nostr_ec_sign(const unsigned char* private_key, const unsigned char* hash, unsigned char* signature);
 
 /**
  * Create and sign a NOSTR event
  */
-cJSON* nostr_create_and_sign_event(int kind, const char* content, cJSON* tags, const unsigned char* private_key, time_t timestamp) {
-    if (!private_key) {
+cJSON* nostr_create_and_sign_event_with_signer(int kind, const char* content, cJSON* tags, nostr_signer_t* signer, time_t timestamp) {
+    cJSON* event = NULL;
+    cJSON* signed_event = NULL;
+    char pubkey_hex[65];
+    int rc;
+
+    if (!signer) {
         return NULL;
     }
-    
+
     if (!content) {
         content = ""; // Default to empty content
     }
-    
-    // Convert private key to public key
-    unsigned char public_key[32];
-    if (nostr_ec_public_key_from_private_key(private_key, public_key) != 0) {
+
+    rc = nostr_signer_get_public_key(signer, pubkey_hex);
+    if (rc != NOSTR_SUCCESS) {
         return NULL;
     }
-    
-    // Convert public key to hex
-    char pubkey_hex[65];
-    nostr_bytes_to_hex(public_key, 32, pubkey_hex);
-    
+
     // Create event structure
-    cJSON* event = cJSON_CreateObject();
+    event = cJSON_CreateObject();
     if (!event) {
         return NULL;
     }
-    
+
     // Use provided timestamp or current time if timestamp is 0
     time_t event_time = (timestamp == 0) ? time(NULL) : timestamp;
-    
+
     cJSON_AddStringToObject(event, "pubkey", pubkey_hex);
     cJSON_AddNumberToObject(event, "created_at", (double)event_time);
     cJSON_AddNumberToObject(event, "kind", kind);
-    
+
     // Add tags (copy provided tags or create empty array)
     if (tags) {
         cJSON_AddItemToObject(event, "tags", cJSON_Duplicate(tags, 1));
     } else {
         cJSON_AddItemToObject(event, "tags", cJSON_CreateArray());
     }
-    
+
     cJSON_AddStringToObject(event, "content", content);
+
+    rc = nostr_signer_sign_event(signer, event, &signed_event);
+    cJSON_Delete(event);
+
+    if (rc != NOSTR_SUCCESS) {
+        return NULL;
+    }
+
+    return signed_event;
+}
+
+cJSON* nostr_create_and_sign_event(int kind, const char* content, cJSON* tags, const unsigned char* private_key, time_t timestamp) {
+    cJSON* out = NULL;
+    nostr_signer_t* signer = NULL;
+
+    if (!private_key) {
+        return NULL;
+    }
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) {
+        return NULL;
+    }
+
+    out = nostr_create_and_sign_event_with_signer(kind, content, tags, signer, timestamp);
+    nostr_signer_free(signer);
+    return out;
+}
+
+/**
+ * Validate the structure of a NOSTR event
+ * Checks required fields, types, and basic format validation
+ */
+int nostr_validate_event_structure(cJSON* event) {
+    if (!event || !cJSON_IsObject(event)) {
+        return NOSTR_ERROR_EVENT_INVALID_STRUCTURE;
+    }
     
-    // ============================================================================
-    // INLINE SERIALIZATION AND SIGNING LOGIC 
-    // ============================================================================
-    
-    // Get event fields for serialization
+    // Check required fields exist
+    cJSON* id_item = cJSON_GetObjectItem(event, "id");
     cJSON* pubkey_item = cJSON_GetObjectItem(event, "pubkey");
     cJSON* created_at_item = cJSON_GetObjectItem(event, "created_at");
     cJSON* kind_item = cJSON_GetObjectItem(event, "kind");
     cJSON* tags_item = cJSON_GetObjectItem(event, "tags");
     cJSON* content_item = cJSON_GetObjectItem(event, "content");
+    cJSON* sig_item = cJSON_GetObjectItem(event, "sig");
     
-    if (!pubkey_item || !created_at_item || !kind_item || !tags_item || !content_item) {
-        cJSON_Delete(event);
-        return NULL;
+    if (!id_item || !pubkey_item || !created_at_item || !kind_item || 
+        !tags_item || !content_item || !sig_item) {
+        return NOSTR_ERROR_EVENT_INVALID_STRUCTURE;
+    }
+    
+    // Validate field types
+    if (!cJSON_IsString(id_item)) return NOSTR_ERROR_EVENT_INVALID_ID;
+    if (!cJSON_IsString(pubkey_item)) return NOSTR_ERROR_EVENT_INVALID_PUBKEY;
+    if (!cJSON_IsNumber(created_at_item)) return NOSTR_ERROR_EVENT_INVALID_CREATED_AT;
+    if (!cJSON_IsNumber(kind_item)) return NOSTR_ERROR_EVENT_INVALID_KIND;
+    if (!cJSON_IsArray(tags_item)) return NOSTR_ERROR_EVENT_INVALID_TAGS;
+    if (!cJSON_IsString(content_item)) return NOSTR_ERROR_EVENT_INVALID_CONTENT;
+    if (!cJSON_IsString(sig_item)) return NOSTR_ERROR_EVENT_INVALID_SIGNATURE;
+    
+    // Validate hex string lengths
+    const char* id_str = cJSON_GetStringValue(id_item);
+    const char* pubkey_str = cJSON_GetStringValue(pubkey_item);
+    const char* sig_str = cJSON_GetStringValue(sig_item);
+    
+    if (!id_str || strlen(id_str) != 64) return NOSTR_ERROR_EVENT_INVALID_ID;
+    if (!pubkey_str || strlen(pubkey_str) != 64) return NOSTR_ERROR_EVENT_INVALID_PUBKEY;
+    if (!sig_str || strlen(sig_str) != 128) return NOSTR_ERROR_EVENT_INVALID_SIGNATURE;
+    
+    // Validate hex characters (lowercase)
+    for (int i = 0; i < 64; i++) {
+        char c = id_str[i];
+        if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f'))) {
+            return NOSTR_ERROR_EVENT_INVALID_ID;
+        }
+        c = pubkey_str[i];
+        if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f'))) {
+            return NOSTR_ERROR_EVENT_INVALID_PUBKEY;
+        }
+    }
+    
+    // Validate signature hex characters (lowercase) - 128 characters
+    for (int i = 0; i < 128; i++) {
+        char c = sig_str[i];
+        if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f'))) {
+            return NOSTR_ERROR_EVENT_INVALID_SIGNATURE;
+        }
+    }
+    
+    // Validate created_at is a valid timestamp (positive number)
+    double created_at = cJSON_GetNumberValue(created_at_item);
+    if (created_at < 0) return NOSTR_ERROR_EVENT_INVALID_CREATED_AT;
+    
+    // Validate kind is valid (0-65535)
+    double kind = cJSON_GetNumberValue(kind_item);
+    if (kind < 0 || kind > 65535 || kind != (int)kind) {
+        return NOSTR_ERROR_EVENT_INVALID_KIND;
+    }
+    
+    // Validate tags array structure (array of arrays of strings)
+    cJSON* tag_item;
+    cJSON_ArrayForEach(tag_item, tags_item) {
+        if (!cJSON_IsArray(tag_item)) {
+            return NOSTR_ERROR_EVENT_INVALID_TAGS;
+        }
+        cJSON* tag_element;
+        cJSON_ArrayForEach(tag_element, tag_item) {
+            if (!cJSON_IsString(tag_element)) {
+                return NOSTR_ERROR_EVENT_INVALID_TAGS;
+            }
+        }
+    }
+    
+    return NOSTR_SUCCESS;
+}
+
+/**
+ * Verify the cryptographic signature of a NOSTR event
+ * Validates event ID and signature according to NIP-01
+ */
+int nostr_verify_event_signature(cJSON* event) {
+    if (!event) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+    
+    // Get event fields
+    cJSON* id_item = cJSON_GetObjectItem(event, "id");
+    cJSON* pubkey_item = cJSON_GetObjectItem(event, "pubkey");
+    cJSON* created_at_item = cJSON_GetObjectItem(event, "created_at");
+    cJSON* kind_item = cJSON_GetObjectItem(event, "kind");
+    cJSON* tags_item = cJSON_GetObjectItem(event, "tags");
+    cJSON* content_item = cJSON_GetObjectItem(event, "content");
+    cJSON* sig_item = cJSON_GetObjectItem(event, "sig");
+    
+    if (!id_item || !pubkey_item || !created_at_item || !kind_item || 
+        !tags_item || !content_item || !sig_item) {
+        return NOSTR_ERROR_EVENT_INVALID_STRUCTURE;
     }
     
     // Create serialization array: [0, pubkey, created_at, kind, tags, content]
     cJSON* serialize_array = cJSON_CreateArray();
     if (!serialize_array) {
-        cJSON_Delete(event);
-        return NULL;
+        return NOSTR_ERROR_MEMORY_FAILED;
     }
     
     cJSON_AddItemToArray(serialize_array, cJSON_CreateNumber(0));
@@ -95,39 +230,74 @@ cJSON* nostr_create_and_sign_event(int kind, const char* content, cJSON* tags, c
     cJSON_Delete(serialize_array);
     
     if (!serialize_string) {
-        cJSON_Delete(event);
-        return NULL;
+        return NOSTR_ERROR_MEMORY_FAILED;
     }
     
     // Hash the serialized event
     unsigned char event_hash[32];
     if (nostr_sha256((const unsigned char*)serialize_string, strlen(serialize_string), event_hash) != 0) {
         free(serialize_string);
-        cJSON_Delete(event);
-        return NULL;
+        return NOSTR_ERROR_CRYPTO_FAILED;
     }
     
-    // Convert hash to hex for event ID
-    char event_id[65];
-    nostr_bytes_to_hex(event_hash, 32, event_id);
+    // Convert hash to hex for event ID verification
+    char calculated_id[65];
+    nostr_bytes_to_hex(event_hash, 32, calculated_id);
     
-    // Sign the hash using ECDSA
-    unsigned char signature[64];
-    if (nostr_ec_sign(private_key, event_hash, signature) != 0) {
+    // Compare with provided event ID
+    const char* provided_id = cJSON_GetStringValue(id_item);
+    if (!provided_id || strcmp(calculated_id, provided_id) != 0) {
         free(serialize_string);
-        cJSON_Delete(event);
-        return NULL;
+        return NOSTR_ERROR_EVENT_INVALID_ID;
     }
     
-    // Convert signature to hex
-    char sig_hex[129];
-    nostr_bytes_to_hex(signature, 64, sig_hex);
+    // Verify signature
+    const char* pubkey_str = cJSON_GetStringValue(pubkey_item);
+    const char* sig_str = cJSON_GetStringValue(sig_item);
     
-    // Add ID and signature to the event
-    cJSON_AddStringToObject(event, "id", event_id);
-    cJSON_AddStringToObject(event, "sig", sig_hex);
+    if (!pubkey_str || !sig_str) {
+        free(serialize_string);
+        return NOSTR_ERROR_EVENT_INVALID_STRUCTURE;
+    }
+    
+    // Convert hex strings to bytes
+    unsigned char pubkey_bytes[32];
+    unsigned char sig_bytes[64];
+    
+    if (nostr_hex_to_bytes(pubkey_str, pubkey_bytes, 32) != 0 ||
+        nostr_hex_to_bytes(sig_str, sig_bytes, 64) != 0) {
+        free(serialize_string);
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+    
+    // Parse the public key into secp256k1 format
+    nostr_secp256k1_xonly_pubkey xonly_pubkey;
+    if (!nostr_secp256k1_xonly_pubkey_parse(&xonly_pubkey, pubkey_bytes)) {
+        free(serialize_string);
+        return NOSTR_ERROR_EVENT_INVALID_PUBKEY;
+    }
+    
+    // Verify Schnorr signature
+    if (!nostr_secp256k1_schnorrsig_verify(sig_bytes, event_hash, &xonly_pubkey)) {
+        free(serialize_string);
+        return NOSTR_ERROR_EVENT_INVALID_SIGNATURE;
+    }
     
     free(serialize_string);
-    
-    return event;
+    return NOSTR_SUCCESS;
+}
+
+/**
+ * Complete validation of a NOSTR event
+ * Performs both structure and cryptographic validation
+ */
+int nostr_validate_event(cJSON* event) {
+    // First validate structure (fast check)
+    int structure_result = nostr_validate_event_structure(event);
+    if (structure_result != NOSTR_SUCCESS) {
+        return structure_result;
+    }
+    
+    // Then verify signature (expensive check)
+    return nostr_verify_event_signature(event);
 }

nostr_core/nip001.h

@@ -10,9 +10,16 @@
 #include <stdint.h>
 #include <time.h>
 #include "../cjson/cJSON.h"
+#include "nostr_signer.h"
 
 
 // Function declarations
 cJSON* nostr_create_and_sign_event(int kind, const char* content, cJSON* tags, const unsigned char* private_key, time_t timestamp);
+cJSON* nostr_create_and_sign_event_with_signer(int kind, const char* content, cJSON* tags, nostr_signer_t* signer, time_t timestamp);
+
+// Event validation functions
+int nostr_validate_event_structure(cJSON* event);
+int nostr_verify_event_signature(cJSON* event);
+int nostr_validate_event(cJSON* event);
 
 #endif // NIP001_H

nostr_core/nip003.h

@@ -0,0 +1,257 @@
+/*
+ * NOSTR Core Library - NIP-03: OpenTimestamps Attestations for Events
+ */
+
+#ifndef NOSTR_NIP03_H
+#define NOSTR_NIP03_H
+
+#include "nostr_common.h"
+#include "nostr_signer.h"
+#include "cjson/cJSON.h"
+#include <time.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define NOSTR_KIND_OT_PROOF 1040
+
+/* Default OTS calendars for multi-calendar stamping */
+#define NOSTR_OTS_DEFAULT_CALENDAR_COUNT 4
+extern const char* NOSTR_OTS_DEFAULT_CALENDARS[NOSTR_OTS_DEFAULT_CALENDAR_COUNT];
+
+/**
+ * Create a NIP-03 OpenTimestamps proof event (kind 1040)
+ * 
+ * @param target_event_id The ID of the event being timestamped (hex string)
+ * @param target_event_kind The kind of the event being timestamped
+ * @param ots_data_base64 Base64 encoded .ots file content
+ * @param relay_url Optional relay URL where the target event can be found
+ * @param private_key 32-byte private key for signing the proof event
+ * @return cJSON* The signed proof event, or NULL on error
+ */
+cJSON* nostr_nip03_create_proof_event(const char* target_event_id,
+                                      int target_event_kind,
+                                      const char* ots_data_base64,
+                                      const char* relay_url,
+                                      const unsigned char* private_key);
+
+/**
+ * Create a NIP-03 OpenTimestamps proof event using a signer (kind 1040)
+ *
+ * @param target_event_id The ID of the event being timestamped (hex string)
+ * @param target_event_kind The kind of the event being timestamped
+ * @param ots_data_base64 Base64 encoded .ots file content
+ * @param relay_url Optional relay URL where the target event can be found
+ * @param signer Signer handle for signing the proof event
+ * @return cJSON* The signed proof event, or NULL on error
+ */
+cJSON* nostr_nip03_create_proof_event_with_signer(const char* target_event_id,
+                                                  int target_event_kind,
+                                                  const char* ots_data_base64,
+                                                  const char* relay_url,
+                                                  nostr_signer_t* signer);
+
+/**
+ * Request a timestamp for an event ID from an OpenTimestamps calendar
+ * 
+ * This function sends the event ID (as a SHA256 digest) to an OTS calendar
+ * and returns the initial .ots file data (base64 encoded).
+ * 
+ * @param event_id_hex The event ID to timestamp (64-char hex string)
+ * @param calendar_url The OTS calendar URL (e.g., "https://alice.btc.calendar.opentimestamps.org")
+ * @param timeout_seconds Request timeout
+ * @return char* Base64 encoded .ots data, or NULL on error (caller must free)
+ */
+char* nostr_nip03_request_timestamp(const char* event_id_hex,
+                                    const char* calendar_url,
+                                    int timeout_seconds);
+
+/**
+ * Check if an OTS proof is complete (has a Bitcoin or Litecoin attestation)
+ *
+ * Parses the OTS binary file format and searches for a Bitcoin block header
+ * attestation (tag 0588960d73d71901) or Litecoin attestation (tag 06856e0d73d71901).
+ * A proof with only pending attestations is not yet complete.
+ *
+ * @param ots_data_base64 Base64 encoded .ots file content
+ * @return int 1 if complete (has Bitcoin/Litecoin attestation), 0 if pending, -1 on error
+ */
+int nostr_nip03_is_proof_complete(const char* ots_data_base64);
+
+/**
+ * Get detailed attestation information from an OTS proof
+ *
+ * Parses the OTS file and extracts information about all attestations found.
+ *
+ * @param ots_data_base64 Base64 encoded .ots file content
+ * @param has_bitcoin Output: 1 if a Bitcoin attestation is present (optional, NULL to skip)
+ * @param has_litecoin Output: 1 if a Litecoin attestation is present (optional, NULL to skip)
+ * @param has_pending Output: 1 if any pending attestations are present (optional, NULL to skip)
+ * @param bitcoin_height Output: Bitcoin block height (optional, NULL to skip)
+ * @param litecoin_height Output: Litecoin block height (optional, NULL to skip)
+ * @param pending_uri_out Output: First pending calendar URI (optional, NULL to skip, caller must free)
+ * @return int 0 on success, -1 on parse error
+ */
+int nostr_nip03_get_attestation_info(const char* ots_data_base64,
+                                     int* has_bitcoin,
+                                     int* has_litecoin,
+                                     int* has_pending,
+                                     uint64_t* bitcoin_height,
+                                     uint64_t* litecoin_height,
+                                     char** pending_uri_out);
+
+/**
+ * Upgrade an OTS proof by fetching missing attestations from a calendar
+ *
+ * Sends the current proof to the calendar's /upgrade endpoint and returns
+ * the updated proof. The calendar may return the same proof if no new
+ * attestations are available, or an upgraded proof with Bitcoin/Litecoin
+ * attestations.
+ *
+ * @param ots_data_base64 Current base64 encoded .ots file content
+ * @param calendar_url The OTS calendar URL
+ * @param timeout_seconds Request timeout
+ * @return char* New base64 encoded .ots data, or NULL on error (caller must free)
+ */
+char* nostr_nip03_upgrade_proof(const char* ots_data_base64,
+                                const char* calendar_url,
+                                int timeout_seconds);
+
+/**
+ * Upgrade an OTS proof by re-submitting the digest to a calendar
+ *
+ * This is the preferred upgrade method for raw timestamp proofs (returned by
+ * the calendar /digest endpoint) which don't contain the file digest.
+ * Re-submits the digest to the calendar, which returns the current proof
+ * that may include new Bitcoin attestations.
+ *
+ * @param digest_hex The 64-char hex SHA-256 digest of the timestamped data
+ * @param calendar_url The OTS calendar URL
+ * @param timeout_seconds Request timeout
+ * @return char* New base64 encoded .ots data, or NULL on error (caller must free)
+ */
+char* nostr_nip03_upgrade_proof_with_digest(const char* digest_hex,
+                                            const char* calendar_url,
+                                            int timeout_seconds);
+
+/**
+ * Upgrade an OTS proof by walking the proof tree and fetching upgraded sub-proofs
+ *
+ * This is the correct upgrade mechanism, matching the reference ots client:
+ *   1. Parses the proof tree
+ *   2. Walks the tree computing intermediate commitment hashes
+ *   3. For each PendingAttestation, calls GET /timestamp/<commitment-hash>
+ *   4. If the calendar returns a proof with a Bitcoin attestation, splices it in
+ *
+ * @param ots_data_base64 Base64 encoded DetachedTimestampFile
+ * @param timeout_seconds Per-request timeout
+ * @return char* New base64 encoded upgraded proof, or NULL if no upgrade available (caller must free)
+ */
+char* nostr_nip03_upgrade_proof_tree(const char* ots_data_base64,
+                                     int timeout_seconds);
+
+/**
+ * Get all pending calendar URIs from an OTS proof
+ *
+ * @param ots_data_base64 Base64 encoded .ots file content
+ * @param uris_out Array of char* pointers (caller must free each string and the array)
+ * @param max_uris Maximum number of URIs to return
+ * @return int Number of pending URIs found, or -1 on error
+ */
+int nostr_nip03_get_pending_uris(const char* ots_data_base64,
+                                 char*** uris_out,
+                                 int max_uris);
+
+/**
+ * Create a full DetachedTimestampFile (.ots) from a digest
+ *
+ * Wraps a SHA-256 digest in the OTS DetachedTimestampFile format with the
+ * proper header magic, version, hash op, and digest. This is the standard
+ * .ots file format that can be verified by the `ots` command-line tool.
+ *
+ * @param digest_hex The 64-char hex SHA-256 digest
+ * @return char* Base64 encoded DetachedTimestampFile, or NULL on error (caller must free)
+ */
+char* nostr_nip03_create_ots_file(const char* digest_hex);
+
+/**
+ * Submit a digest to multiple calendars and create a combined proof
+ *
+ * Submits the digest to each calendar, collects all the returned timestamps,
+ * and combines them into a single DetachedTimestampFile with a fork operation.
+ * This is the recommended way to timestamp data — using multiple calendars
+ * provides redundancy.
+ *
+ * @param digest_hex The 64-char hex SHA-256 digest
+ * @param calendar_urls Array of calendar URLs
+ * @param calendar_count Number of calendars
+ * @param timeout_seconds Per-request timeout
+ * @return char* Base64 encoded DetachedTimestampFile with all calendar proofs, or NULL on error
+ */
+char* nostr_nip03_stamp_with_multiple_calendars(const char* digest_hex,
+                                                const char** calendar_urls,
+                                                int calendar_count,
+                                                int timeout_seconds);
+
+/**
+ * Request a timestamp for an event ID from multiple OTS calendars
+ *
+ * Submits the event ID to multiple calendars and combines the results into a
+ * single DetachedTimestampFile. Uses the default calendars if none specified.
+ *
+ * @param event_id_hex The event ID to timestamp (64-char hex string)
+ * @param calendar_urls Array of calendar URLs (NULL to use defaults)
+ * @param calendar_count Number of calendars (0 to use defaults)
+ * @param timeout_seconds Per-request timeout
+ * @return char* Base64 encoded DetachedTimestampFile, or NULL on error (caller must free)
+ */
+char* nostr_nip03_request_timestamp_multi(const char* event_id_hex,
+                                          const char** calendar_urls,
+                                          int calendar_count,
+                                          int timeout_seconds);
+
+/**
+ * Upgrade an OTS proof by re-submitting to multiple calendars
+ *
+ * Re-submits the digest to all specified calendars (or defaults) and returns
+ * a new combined proof. The proof may now contain Bitcoin attestations if
+ * any calendar has committed since the original submission.
+ *
+ * @param digest_hex The 64-char hex SHA-256 digest
+ * @param calendar_urls Array of calendar URLs (NULL to use defaults)
+ * @param calendar_count Number of calendars (0 to use defaults)
+ * @param timeout_seconds Per-request timeout
+ * @return char* New base64 encoded DetachedTimestampFile, or NULL on error (caller must free)
+ */
+char* nostr_nip03_upgrade_proof_multi(const char* digest_hex,
+                                      const char** calendar_urls,
+                                      int calendar_count,
+                                      int timeout_seconds);
+
+/**
+ * Verify an OTS proof structurally
+ *
+ * Parses the OTS file, optionally verifies the file digest matches the
+ * expected target, and checks for a Bitcoin block header attestation.
+ *
+ * Note: Full on-chain verification (checking the Bitcoin block header's
+ * merkle root) requires fetching the block header from a blockchain API.
+ * This function performs structural verification only.
+ *
+ * @param ots_data_base64 Base64 encoded .ots file content
+ * @param target_digest_hex Expected SHA256 digest of the timestamped data (64-char hex, or NULL to skip)
+ * @param block_height_out Output: Bitcoin block height (optional, NULL to skip)
+ * @param block_time_out Output: Block time (optional, NULL to skip, always 0 for structural verification)
+ * @return int 0 on success (verified), 1 if no Bitcoin attestation found, -1 on parse error, -2 on digest mismatch
+ */
+int nostr_nip03_verify_proof(const char* ots_data_base64,
+                             const char* target_digest_hex,
+                             uint64_t* block_height_out,
+                             time_t* block_time_out);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_NIP03_H */

nostr_core/nip004.c

@@ -6,13 +6,24 @@
 #include "nip004.h"
 #include "utils.h"
 #include "nostr_common.h"
-#include "crypto/nostr_secp256k1.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
-// Include our AES implementation
-#include "crypto/nostr_aes.h"
+// Forward declarations for crypto functions (private API)
+// These functions are implemented in crypto/ but not exposed through public headers
+int ecdh_shared_secret(const unsigned char* private_key, const unsigned char* public_key, unsigned char* shared_secret);
+int nostr_secp256k1_get_random_bytes(unsigned char* buf, size_t len);
+
+// AES context and functions for NIP-04 encryption
+struct AES_ctx {
+    unsigned char RoundKey[240];  // AES-256 key expansion
+    unsigned char Iv[16];         // Initialization vector
+};
+
+void AES_init_ctx_iv(struct AES_ctx* ctx, const unsigned char* key, const unsigned char* iv);
+void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, unsigned char* buf, size_t length);
+void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, unsigned char* buf, size_t length);
 
 // Forward declarations for internal functions
 static int aes_cbc_encrypt(const unsigned char* key, const unsigned char* iv,

nostr_core/nip004.h

@@ -13,7 +13,7 @@ extern "C" {
 #endif
 
 // NIP-04 constants
-// #define NOSTR_NIP04_MAX_PLAINTEXT_SIZE 65535
+// #define NOSTR_NIP04_MAX_PLAINTEXT_SIZE 1048576    // 1MB
 // NIP-04 Constants
 // #define NOSTR_NIP04_MAX_PLAINTEXT_SIZE 16777216    // 16MB
 // #define NOSTR_NIP04_MAX_ENCRYPTED_SIZE 22369621    // ~21.3MB (accounts for base64 overhead + IV)

nostr_core/nip005.c

@@ -12,46 +12,7 @@
 #include <ctype.h>
 
 
-#include <curl/curl.h>
-
-
-// Structure for HTTP response handling
-typedef struct {
-    char* data;
-    size_t size;
-    size_t capacity;
-} nip05_http_response_t;
-
-/**
- * Callback function for curl to write HTTP response data
- */
-static size_t nip05_write_callback(void* contents, size_t size, size_t nmemb, void* userp) {
-    nip05_http_response_t* response = (nip05_http_response_t*)userp;
-    size_t total_size = size * nmemb;
-    
-    // Check if we need to expand the buffer
-    if (response->size + total_size >= response->capacity) {
-        size_t new_capacity = response->capacity * 2;
-        if (new_capacity < response->size + total_size + 1) {
-            new_capacity = response->size + total_size + 1;
-        }
-        
-        char* new_data = realloc(response->data, new_capacity);
-        if (!new_data) {
-            return 0; // Out of memory
-        }
-        
-        response->data = new_data;
-        response->capacity = new_capacity;
-    }
-    
-    // Append the new data
-    memcpy(response->data + response->size, contents, total_size);
-    response->size += total_size;
-    response->data[response->size] = '\0';
-    
-    return total_size;
-}
+#include "nostr_http.h"
 
 /**
  * Parse and validate a NIP-05 identifier into local part and domain
@@ -104,49 +65,22 @@ static int nip05_http_get(const char* url, int timeout_seconds, char** response_
     if (!url || !response_data) {
         return NOSTR_ERROR_INVALID_INPUT;
     }
-    
-    CURL* curl = curl_easy_init();
-    if (!curl) {
-        return NOSTR_ERROR_NETWORK_FAILED;
-    }
-    
-    nip05_http_response_t response = {0};
-    response.capacity = 1024;
-    response.data = malloc(response.capacity);
-    if (!response.data) {
-        curl_easy_cleanup(curl);
-        return NOSTR_ERROR_MEMORY_FAILED;
-    }
-    response.data[0] = '\0';
-    
-    // Set curl options with proper type casting to fix warnings
-    curl_easy_setopt(curl, CURLOPT_URL, url);
-    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, (curl_write_callback)nip05_write_callback);
-    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response);
-    curl_easy_setopt(curl, CURLOPT_TIMEOUT, (long)(timeout_seconds > 0 ? timeout_seconds : NIP05_DEFAULT_TIMEOUT));
-    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 0L); // NIP-05 forbids redirects
-    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
-    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 2L);
-    curl_easy_setopt(curl, CURLOPT_USERAGENT, "nostr-core/1.0");
-    
-    // Perform the request
-    CURLcode res = curl_easy_perform(curl);
-    long response_code = 0;
-    curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &response_code);
-    
-    curl_easy_cleanup(curl);
-    
-    if (res != CURLE_OK) {
-        free(response.data);
+
+    long status = 0;
+    int rc = nostr_http_get(url,
+                            timeout_seconds > 0 ? timeout_seconds : NIP05_DEFAULT_TIMEOUT,
+                            response_data,
+                            &status);
+    if (rc != NOSTR_SUCCESS) {
         return NOSTR_ERROR_NIP05_HTTP_FAILED;
     }
-    
-    if (response_code != 200) {
-        free(response.data);
+
+    if (status != 200) {
+        free(*response_data);
+        *response_data = NULL;
         return NOSTR_ERROR_NIP05_HTTP_FAILED;
     }
-    
-    *response_data = response.data;
+
     return NOSTR_SUCCESS;
 }
 

nostr_core/nip006.c

@@ -10,24 +10,17 @@
 #include <ctype.h>
 #include <time.h>
 #include "../nostr_core/nostr_common.h"
+#include "nostr_platform.h"
 
 int nostr_generate_keypair(unsigned char* private_key, unsigned char* public_key) {
     if (!private_key || !public_key) {
         return NOSTR_ERROR_INVALID_INPUT;
     }
     
-    // Generate random entropy using /dev/urandom
-    FILE* urandom = fopen("/dev/urandom", "rb");
-    if (!urandom) {
+    if (nostr_platform_random(private_key, 32) != 0) {
         return NOSTR_ERROR_IO_FAILED;
     }
     
-    if (fread(private_key, 1, 32, urandom) != 32) {
-        fclose(urandom);
-        return NOSTR_ERROR_IO_FAILED;
-    }
-    fclose(urandom);
-    
     // Validate private key
     if (nostr_ec_private_key_verify(private_key) != 0) {
         return NOSTR_ERROR_CRYPTO_FAILED;
@@ -50,17 +43,10 @@ int nostr_generate_mnemonic_and_keys(char* mnemonic, size_t mnemonic_size,
     
     // Generate entropy for 12-word mnemonic
     unsigned char entropy[16];
-    FILE* urandom = fopen("/dev/urandom", "rb");
-    if (!urandom) {
+    if (nostr_platform_random(entropy, sizeof(entropy)) != 0) {
         return NOSTR_ERROR_IO_FAILED;
     }
     
-    if (fread(entropy, 1, sizeof(entropy), urandom) != sizeof(entropy)) {
-        fclose(urandom);
-        return NOSTR_ERROR_IO_FAILED;
-    }
-    fclose(urandom);
-    
     // Generate mnemonic from entropy
     if (nostr_bip39_mnemonic_from_bytes(entropy, sizeof(entropy), mnemonic) != 0) {
         return NOSTR_ERROR_CRYPTO_FAILED;

nostr_core/nip011.c

@@ -11,50 +11,13 @@
 
 #ifndef DISABLE_NIP05 // NIP-11 uses the same HTTP infrastructure as NIP-05
 
-#include <curl/curl.h>
+#include "nostr_http.h"
 
 // Maximum sizes for NIP-11 operations
 #define NIP11_MAX_URL_SIZE 512
 #define NIP11_MAX_RESPONSE_SIZE 16384
 #define NIP11_DEFAULT_TIMEOUT 10
 
-// Structure for HTTP response handling (same as NIP-05)
-typedef struct {
-    char* data;
-    size_t size;
-    size_t capacity;
-} nip11_http_response_t;
-
-/**
- * Callback function for curl to write HTTP response data
- */
-static size_t nip11_write_callback(void* contents, size_t size, size_t nmemb, nip11_http_response_t* response) {
-    size_t total_size = size * nmemb;
-    
-    // Check if we need to expand the buffer
-    if (response->size + total_size >= response->capacity) {
-        size_t new_capacity = response->capacity * 2;
-        if (new_capacity < response->size + total_size + 1) {
-            new_capacity = response->size + total_size + 1;
-        }
-        
-        char* new_data = realloc(response->data, new_capacity);
-        if (!new_data) {
-            return 0; // Out of memory
-        }
-        
-        response->data = new_data;
-        response->capacity = new_capacity;
-    }
-    
-    // Append the new data
-    memcpy(response->data + response->size, contents, total_size);
-    response->size += total_size;
-    response->data[response->size] = '\0';
-    
-    return total_size;
-}
-
 /**
  * Convert WebSocket URL to HTTP URL for NIP-11 document retrieval
  */
@@ -341,60 +304,35 @@ int nostr_nip11_fetch_relay_info(const char* relay_url, nostr_relay_info_t** inf
         return NOSTR_ERROR_MEMORY_FAILED;
     }
     
-    // Make HTTP request with NIP-11 required header
-    CURL* curl = curl_easy_init();
-    if (!curl) {
-        free(http_url);
-        free(info);
-        return NOSTR_ERROR_NETWORK_FAILED;
-    }
-    
-    // Use the HTTP response structure
-    nip11_http_response_t response = {0};
-    response.capacity = 1024;
-    response.data = malloc(response.capacity);
-    if (!response.data) {
-        curl_easy_cleanup(curl);
-        free(http_url);
-        free(info);
-        return NOSTR_ERROR_MEMORY_FAILED;
-    }
-    response.data[0] = '\0';
-    
-    // Set up headers for NIP-11
-    struct curl_slist* headers = NULL;
-    headers = curl_slist_append(headers, "Accept: application/nostr+json");
-    
-    // Set curl options - use proper function pointer cast
-    curl_easy_setopt(curl, CURLOPT_URL, http_url);
-    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
-    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, (curl_write_callback)nip11_write_callback);
-    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response);
-    curl_easy_setopt(curl, CURLOPT_TIMEOUT, (long)(timeout_seconds > 0 ? timeout_seconds : NIP11_DEFAULT_TIMEOUT));
-    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L); // NIP-11 allows redirects
-    curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 3L);
-    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
-    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 2L);
-    curl_easy_setopt(curl, CURLOPT_USERAGENT, "nostr-core/1.0");
-    
-    // Perform the request
-    CURLcode res = curl_easy_perform(curl);
-    long response_code = 0;
-    curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &response_code);
-    
-    curl_slist_free_all(headers);
-    curl_easy_cleanup(curl);
+    const char* headers[] = {
+        "Accept: application/nostr+json",
+        NULL
+    };
+
+    nostr_http_request_t req;
+    memset(&req, 0, sizeof(req));
+    req.method = "GET";
+    req.url = http_url;
+    req.headers = headers;
+    req.timeout_seconds = timeout_seconds > 0 ? timeout_seconds : NIP11_DEFAULT_TIMEOUT;
+    req.follow_redirects = 1;
+    req.max_redirects = 3;
+
+    nostr_http_response_t response;
+    int http_rc = nostr_http_request(&req, &response);
     free(http_url);
-    
-    if (res != CURLE_OK || response_code != 200) {
-        free(response.data);
+
+    if (http_rc != NOSTR_SUCCESS || response.status_code != 200) {
+        if (http_rc == NOSTR_SUCCESS) {
+            nostr_http_response_free(&response);
+        }
         free(info);
         return NOSTR_ERROR_NIP05_HTTP_FAILED;
     }
-    
+
     // Parse the relay information
-    int parse_result = nip11_parse_relay_info(response.data, info);
-    free(response.data);
+    int parse_result = nip11_parse_relay_info(response.body, info);
+    nostr_http_response_free(&response);
     
     if (parse_result != NOSTR_SUCCESS) {
         nostr_nip11_relay_info_free(info);

nostr_core/nip013.c

@@ -6,6 +6,7 @@
 #include "nip001.h"
 #include "utils.h"
 #include "../cjson/cJSON.h"
+#include "nostr_log.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -175,12 +176,13 @@ int nostr_add_proof_of_work(cJSON* event, const unsigned char* private_key,
         if (attempts % timestamp_update_interval == 0) {
             current_timestamp = time(NULL);
 #ifdef ENABLE_DEBUG_LOGGING
-            FILE* f = fopen("debug.log", "a"); 
-            if (f) { 
-                fprintf(f, "PoW mining: %d attempts, best this round: %d, overall best: %d, goal: %d\n", 
-                        attempts, best_difficulty_this_round, best_difficulty_overall, target_difficulty); 
-                fclose(f); 
-            }
+            nostr_log_emitf(NOSTR_LOG_LEVEL_DEBUG,
+                            "nip013",
+                            "PoW mining: %d attempts, best this round: %d, overall best: %d, goal: %d",
+                            attempts,
+                            best_difficulty_this_round,
+                            best_difficulty_overall,
+                            target_difficulty);
 #endif
             // Reset best difficulty for the new round
             best_difficulty_this_round = 0;
@@ -239,18 +241,22 @@ int nostr_add_proof_of_work(cJSON* event, const unsigned char* private_key,
         // Check if we've reached the target
         if (current_difficulty >= target_difficulty) {
 #ifdef ENABLE_DEBUG_LOGGING
-            FILE* f = fopen("debug.log", "a"); 
-            if (f) { 
-                fprintf(f, "PoW SUCCESS: Found difficulty %d (target %d) at nonce %llu after %d attempts\n", 
-                        current_difficulty, target_difficulty, (unsigned long long)nonce, attempts + 1);
-                
-                // Print the final event JSON
-                char* event_json = cJSON_Print(test_event);
-                if (event_json) {
-                    fprintf(f, "Final event: %s\n", event_json);
-                    free(event_json);
-                }
-                fclose(f); 
+            nostr_log_emitf(NOSTR_LOG_LEVEL_INFO,
+                            "nip013",
+                            "PoW SUCCESS: Found difficulty %d (target %d) at nonce %llu after %d attempts",
+                            current_difficulty,
+                            target_difficulty,
+                            (unsigned long long)nonce,
+                            attempts + 1);
+
+            // Print the final event JSON
+            char* event_json = cJSON_Print(test_event);
+            if (event_json) {
+                nostr_log_emitf(NOSTR_LOG_LEVEL_DEBUG,
+                                "nip013",
+                                "Final event: %s",
+                                event_json);
+                free(event_json);
             }
 #endif
             
@@ -267,13 +273,341 @@ int nostr_add_proof_of_work(cJSON* event, const unsigned char* private_key,
     
 #ifdef ENABLE_DEBUG_LOGGING
     // Debug logging - failure
-    FILE* f = fopen("debug.log", "a"); 
-    if (f) { 
-        fprintf(f, "PoW FAILED: Mining failed after %d attempts\n", max_attempts); 
-        fclose(f); 
-    }
+    nostr_log_emitf(NOSTR_LOG_LEVEL_WARN,
+                    "nip013",
+                    "PoW FAILED: Mining failed after %d attempts",
+                    max_attempts);
 #endif
     
     // If we reach here, we've exceeded max attempts
     return NOSTR_ERROR_CRYPTO_FAILED;
 }
+
+/**
+ * Calculate PoW difficulty (leading zero bits) for an event ID
+ *
+ * @param event_id_hex Hexadecimal event ID string (64 characters)
+ * @return Number of leading zero bits, or negative error code on failure
+ */
+int nostr_calculate_pow_difficulty(const char* event_id_hex) {
+    if (!event_id_hex) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+    
+    // Validate hex string length (should be 64 characters for SHA-256)
+    size_t hex_len = strlen(event_id_hex);
+    if (hex_len != 64) {
+        return NOSTR_ERROR_NIP13_CALCULATION;
+    }
+    
+    // Convert hex to bytes
+    unsigned char hash[32];
+    if (nostr_hex_to_bytes(event_id_hex, hash, 32) != NOSTR_SUCCESS) {
+        return NOSTR_ERROR_NIP13_CALCULATION;
+    }
+    
+    // Use existing NIP-13 reference implementation
+    return count_leading_zero_bits(hash);
+}
+
+/**
+ * Extract nonce information from event tags
+ *
+ * @param event Complete event JSON object
+ * @param nonce_out Output pointer for nonce value (can be NULL)
+ * @param target_difficulty_out Output pointer for target difficulty (can be NULL)
+ * @return NOSTR_SUCCESS if nonce tag found, NOSTR_ERROR_NIP13_NO_NONCE_TAG if not found, other error codes on failure
+ */
+int nostr_extract_nonce_info(cJSON* event, uint64_t* nonce_out, int* target_difficulty_out) {
+    if (!event) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+    
+    // Initialize output values
+    if (nonce_out) *nonce_out = 0;
+    if (target_difficulty_out) *target_difficulty_out = -1;
+    
+    // Get tags array
+    cJSON* tags = cJSON_GetObjectItem(event, "tags");
+    if (!tags || !cJSON_IsArray(tags)) {
+        return NOSTR_ERROR_NIP13_NO_NONCE_TAG;
+    }
+    
+    // Search for nonce tag
+    cJSON* tag = NULL;
+    cJSON_ArrayForEach(tag, tags) {
+        if (!cJSON_IsArray(tag) || cJSON_GetArraySize(tag) < 2) {
+            continue;
+        }
+        
+        // Check if this is a nonce tag
+        cJSON* tag_type = cJSON_GetArrayItem(tag, 0);
+        if (!tag_type || !cJSON_IsString(tag_type)) {
+            continue;
+        }
+        
+        const char* tag_name = cJSON_GetStringValue(tag_type);
+        if (!tag_name || strcmp(tag_name, "nonce") != 0) {
+            continue;
+        }
+        
+        // Extract nonce value (second element)
+        cJSON* nonce_item = cJSON_GetArrayItem(tag, 1);
+        if (!nonce_item || !cJSON_IsString(nonce_item)) {
+            return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+        }
+        
+        const char* nonce_str = cJSON_GetStringValue(nonce_item);
+        if (!nonce_str) {
+            return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+        }
+        
+        // Parse nonce value
+        char* endptr;
+        uint64_t nonce_val = strtoull(nonce_str, &endptr, 10);
+        if (*endptr != '\0') {
+            return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+        }
+        
+        if (nonce_out) *nonce_out = nonce_val;
+        
+        // Extract target difficulty (third element, optional)
+        if (cJSON_GetArraySize(tag) >= 3) {
+            cJSON* target_item = cJSON_GetArrayItem(tag, 2);
+            if (target_item && cJSON_IsString(target_item)) {
+                const char* target_str = cJSON_GetStringValue(target_item);
+                if (target_str) {
+                    char* endptr2;
+                    long target_val = strtol(target_str, &endptr2, 10);
+                    if (*endptr2 == '\0' && target_val >= 0) {
+                        if (target_difficulty_out) *target_difficulty_out = (int)target_val;
+                    }
+                }
+            }
+        }
+        
+        return NOSTR_SUCCESS;
+    }
+    
+    // No nonce tag found
+    return NOSTR_ERROR_NIP13_NO_NONCE_TAG;
+}
+
+/**
+ * Validate just the nonce tag format (without PoW calculation)
+ *
+ * @param nonce_tag_array JSON array representing a nonce tag
+ * @return NOSTR_SUCCESS if valid format, error code otherwise
+ */
+int nostr_validate_nonce_tag(cJSON* nonce_tag_array) {
+    if (!nonce_tag_array || !cJSON_IsArray(nonce_tag_array)) {
+        return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+    }
+    
+    int array_size = cJSON_GetArraySize(nonce_tag_array);
+    if (array_size < 2) {
+        return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+    }
+    
+    // First element should be "nonce"
+    cJSON* tag_type = cJSON_GetArrayItem(nonce_tag_array, 0);
+    if (!tag_type || !cJSON_IsString(tag_type)) {
+        return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+    }
+    
+    const char* tag_name = cJSON_GetStringValue(tag_type);
+    if (!tag_name || strcmp(tag_name, "nonce") != 0) {
+        return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+    }
+    
+    // Second element should be a valid nonce (numeric string)
+    cJSON* nonce_item = cJSON_GetArrayItem(nonce_tag_array, 1);
+    if (!nonce_item || !cJSON_IsString(nonce_item)) {
+        return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+    }
+    
+    const char* nonce_str = cJSON_GetStringValue(nonce_item);
+    if (!nonce_str) {
+        return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+    }
+    
+    // Validate nonce is a valid number
+    char* endptr;
+    strtoull(nonce_str, &endptr, 10);
+    if (*endptr != '\0') {
+        return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+    }
+    
+    // Third element (target difficulty) is optional, but if present should be valid
+    if (array_size >= 3) {
+        cJSON* target_item = cJSON_GetArrayItem(nonce_tag_array, 2);
+        if (target_item && cJSON_IsString(target_item)) {
+            const char* target_str = cJSON_GetStringValue(target_item);
+            if (target_str) {
+                char* endptr2;
+                strtol(target_str, &endptr2, 10);
+                if (*endptr2 != '\0') {
+                    return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+                }
+            }
+        }
+    }
+    
+    return NOSTR_SUCCESS;
+}
+
+/**
+ * Validate Proof of Work for an event according to NIP-13
+ *
+ * @param event Complete event JSON object to validate
+ * @param min_difficulty Minimum difficulty required by the relay (0 = no requirement)
+ * @param validation_flags Bitflags for validation options
+ * @param result_info Optional output struct for detailed results (can be NULL)
+ * @return NOSTR_SUCCESS if PoW is valid and meets requirements, error code otherwise
+ */
+int nostr_validate_pow(cJSON* event, int min_difficulty, int validation_flags,
+                      nostr_pow_result_t* result_info) {
+    if (!event) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+    
+    // Initialize result info if provided
+    if (result_info) {
+        result_info->actual_difficulty = 0;
+        result_info->committed_target = -1;
+        result_info->nonce_value = 0;
+        result_info->has_nonce_tag = 0;
+        result_info->error_detail[0] = '\0';
+    }
+    
+    // Get event ID for PoW calculation
+    cJSON* id_item = cJSON_GetObjectItem(event, "id");
+    if (!id_item || !cJSON_IsString(id_item)) {
+        if (result_info) {
+            snprintf(result_info->error_detail, sizeof(result_info->error_detail),
+                    "Missing or invalid event ID");
+        }
+        return NOSTR_ERROR_EVENT_INVALID_ID;
+    }
+    
+    const char* event_id = cJSON_GetStringValue(id_item);
+    if (!event_id) {
+        if (result_info) {
+            snprintf(result_info->error_detail, sizeof(result_info->error_detail),
+                    "Event ID is not a string");
+        }
+        return NOSTR_ERROR_EVENT_INVALID_ID;
+    }
+    
+    // Calculate actual PoW difficulty
+    int actual_difficulty = nostr_calculate_pow_difficulty(event_id);
+    if (actual_difficulty < 0) {
+        if (result_info) {
+            snprintf(result_info->error_detail, sizeof(result_info->error_detail),
+                    "Failed to calculate PoW difficulty");
+        }
+        return actual_difficulty; // Return the specific error from calculation
+    }
+    
+    if (result_info) {
+        result_info->actual_difficulty = actual_difficulty;
+    }
+    
+    // Check if minimum difficulty requirement is met
+    if (min_difficulty > 0 && actual_difficulty < min_difficulty) {
+        if (result_info) {
+            snprintf(result_info->error_detail, sizeof(result_info->error_detail),
+                    "Insufficient difficulty: %d < %d", actual_difficulty, min_difficulty);
+        }
+        return NOSTR_ERROR_NIP13_INSUFFICIENT;
+    }
+    
+    // Extract nonce information if validation flags require it
+    uint64_t nonce_value = 0;
+    int committed_target = -1;
+    int nonce_extract_result = nostr_extract_nonce_info(event, &nonce_value, &committed_target);
+    
+    if (result_info) {
+        result_info->nonce_value = nonce_value;
+        result_info->committed_target = committed_target;
+        result_info->has_nonce_tag = (nonce_extract_result == NOSTR_SUCCESS) ? 1 : 0;
+    }
+    
+    // Validate nonce tag presence if required
+    if (validation_flags & NOSTR_POW_VALIDATE_NONCE_TAG) {
+        if (nonce_extract_result == NOSTR_ERROR_NIP13_NO_NONCE_TAG) {
+            if (result_info) {
+                snprintf(result_info->error_detail, sizeof(result_info->error_detail),
+                        "Missing required nonce tag");
+            }
+            return NOSTR_ERROR_NIP13_NO_NONCE_TAG;
+        } else if (nonce_extract_result != NOSTR_SUCCESS) {
+            if (result_info) {
+                snprintf(result_info->error_detail, sizeof(result_info->error_detail),
+                        "Invalid nonce tag format");
+            }
+            return nonce_extract_result;
+        }
+        
+        // If strict format validation is enabled, validate the nonce tag structure
+        if (validation_flags & NOSTR_POW_STRICT_FORMAT) {
+            cJSON* tags = cJSON_GetObjectItem(event, "tags");
+            if (tags && cJSON_IsArray(tags)) {
+                cJSON* tag = NULL;
+                cJSON_ArrayForEach(tag, tags) {
+                    if (cJSON_IsArray(tag) && cJSON_GetArraySize(tag) >= 2) {
+                        cJSON* tag_type = cJSON_GetArrayItem(tag, 0);
+                        if (tag_type && cJSON_IsString(tag_type)) {
+                            const char* tag_name = cJSON_GetStringValue(tag_type);
+                            if (tag_name && strcmp(tag_name, "nonce") == 0) {
+                                int validation_result = nostr_validate_nonce_tag(tag);
+                                if (validation_result != NOSTR_SUCCESS) {
+                                    if (result_info) {
+                                        snprintf(result_info->error_detail, sizeof(result_info->error_detail),
+                                                "Nonce tag failed strict format validation");
+                                    }
+                                    return validation_result;
+                                }
+                                break;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+    
+    // Validate committed target difficulty if required
+    if (validation_flags & NOSTR_POW_VALIDATE_TARGET_COMMIT) {
+        if (nonce_extract_result == NOSTR_SUCCESS && committed_target == -1) {
+            if (result_info) {
+                snprintf(result_info->error_detail, sizeof(result_info->error_detail),
+                        "Missing committed target difficulty in nonce tag");
+            }
+            return NOSTR_ERROR_NIP13_INVALID_NONCE_TAG;
+        }
+        
+        // Check for target/difficulty mismatch if rejecting lower targets
+        if (validation_flags & NOSTR_POW_REJECT_LOWER_TARGET) {
+            // According to NIP-13: "if you require 40 bits to reply to your thread and see
+            // a committed target of 30, you can safely reject it even if the note has 40 bits difficulty"
+            // This means we reject if committed_target < min_difficulty, not actual_difficulty
+            if (committed_target != -1 && min_difficulty > 0 && committed_target < min_difficulty) {
+                if (result_info) {
+                    snprintf(result_info->error_detail, sizeof(result_info->error_detail),
+                            "Committed target (%d) is lower than required minimum (%d)",
+                            committed_target, min_difficulty);
+                }
+                return NOSTR_ERROR_NIP13_TARGET_MISMATCH;
+            }
+        }
+    }
+    
+    // All validations passed
+    if (result_info) {
+        snprintf(result_info->error_detail, sizeof(result_info->error_detail),
+                "PoW validation successful");
+    }
+    
+    return NOSTR_SUCCESS;
+}

nostr_core/nip013.h

@@ -8,11 +8,41 @@
 #include "nip001.h"
 #include <stdint.h>
 
+// PoW validation flags
+#define NOSTR_POW_VALIDATE_NONCE_TAG     0x01  // Require and validate nonce tag format
+#define NOSTR_POW_VALIDATE_TARGET_COMMIT  0x02  // Validate committed target difficulty
+#define NOSTR_POW_REJECT_LOWER_TARGET    0x04  // Reject if committed target < actual difficulty
+#define NOSTR_POW_STRICT_FORMAT          0x08  // Strict nonce tag format validation
+
+// Convenience combinations
+#define NOSTR_POW_VALIDATE_BASIC         (NOSTR_POW_VALIDATE_NONCE_TAG)
+#define NOSTR_POW_VALIDATE_FULL          (NOSTR_POW_VALIDATE_NONCE_TAG | NOSTR_POW_VALIDATE_TARGET_COMMIT)
+#define NOSTR_POW_VALIDATE_ANTI_SPAM     (NOSTR_POW_VALIDATE_FULL | NOSTR_POW_REJECT_LOWER_TARGET)
+
+// Result information structure (optional output)
+typedef struct {
+    int actual_difficulty;        // Calculated difficulty (leading zero bits)
+    int committed_target;         // Target difficulty from nonce tag (-1 if none)
+    uint64_t nonce_value;        // Nonce value from tag (0 if none)
+    int has_nonce_tag;           // 1 if nonce tag present, 0 otherwise
+    char error_detail[256];      // Detailed error description
+} nostr_pow_result_t;
+
 // Function declarations
-int nostr_add_proof_of_work(cJSON* event, const unsigned char* private_key, 
+int nostr_add_proof_of_work(cJSON* event, const unsigned char* private_key,
                            int target_difficulty, int max_attempts,
                            int progress_report_interval, int timestamp_update_interval,
                            void (*progress_callback)(int current_difficulty, uint64_t nonce, void* user_data),
                            void* user_data);
 
+// PoW validation functions
+int nostr_validate_pow(cJSON* event, int min_difficulty, int validation_flags,
+                      nostr_pow_result_t* result_info);
+
+int nostr_calculate_pow_difficulty(const char* event_id_hex);
+
+int nostr_extract_nonce_info(cJSON* event, uint64_t* nonce_out, int* target_difficulty_out);
+
+int nostr_validate_nonce_tag(cJSON* nonce_tag_array);
+
 #endif // NIP013_H

nostr_core/nip017.c

@@ -0,0 +1,475 @@
+/*
+ * NIP-17: Private Direct Messages Implementation
+ * https://github.com/nostr-protocol/nips/blob/master/17.md
+ */
+
+#define _GNU_SOURCE
+#include "nip017.h"
+#include "nip059.h"
+#include "nip001.h"
+#include "utils.h"
+#include "nostr_common.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+// Forward declarations for crypto functions
+int nostr_ec_public_key_from_private_key(const unsigned char* private_key, unsigned char* public_key);
+
+/**
+ * Create tags array for DM events
+ */
+static cJSON* create_dm_tags(const char** recipient_pubkeys,
+                           int num_recipients,
+                           const char* subject,
+                           const char* reply_to_event_id,
+                           const char* reply_relay_url) {
+    cJSON* tags = cJSON_CreateArray();
+    if (!tags) return NULL;
+
+    // Add "p" tags for each recipient
+    for (int i = 0; i < num_recipients; i++) {
+        cJSON* p_tag = cJSON_CreateArray();
+        if (!p_tag) {
+            cJSON_Delete(tags);
+            return NULL;
+        }
+        cJSON_AddItemToArray(p_tag, cJSON_CreateString("p"));
+        cJSON_AddItemToArray(p_tag, cJSON_CreateString(recipient_pubkeys[i]));
+        // Add relay URL if provided (recommended)
+        if (reply_relay_url) {
+            cJSON_AddItemToArray(p_tag, cJSON_CreateString(reply_relay_url));
+        }
+        cJSON_AddItemToArray(tags, p_tag);
+    }
+
+    // Add subject tag if provided
+    if (subject && strlen(subject) > 0) {
+        cJSON* subject_tag = cJSON_CreateArray();
+        if (!subject_tag) {
+            cJSON_Delete(tags);
+            return NULL;
+        }
+        cJSON_AddItemToArray(subject_tag, cJSON_CreateString("subject"));
+        cJSON_AddItemToArray(subject_tag, cJSON_CreateString(subject));
+        cJSON_AddItemToArray(tags, subject_tag);
+    }
+
+    // Add reply reference if provided
+    if (reply_to_event_id && strlen(reply_to_event_id) > 0) {
+        cJSON* e_tag = cJSON_CreateArray();
+        if (!e_tag) {
+            cJSON_Delete(tags);
+            return NULL;
+        }
+        cJSON_AddItemToArray(e_tag, cJSON_CreateString("e"));
+        cJSON_AddItemToArray(e_tag, cJSON_CreateString(reply_to_event_id));
+        if (reply_relay_url) {
+            cJSON_AddItemToArray(e_tag, cJSON_CreateString(reply_relay_url));
+        }
+        // For replies, add "reply" marker as per NIP-17
+        cJSON_AddItemToArray(e_tag, cJSON_CreateString("reply"));
+        cJSON_AddItemToArray(tags, e_tag);
+    }
+
+    return tags;
+}
+
+/**
+ * NIP-17: Create a chat message event (kind 14)
+ */
+cJSON* nostr_nip17_create_chat_event(const char* message,
+                                    const char** recipient_pubkeys,
+                                    int num_recipients,
+                                    const char* subject,
+                                    const char* reply_to_event_id,
+                                    const char* reply_relay_url,
+                                    const char* sender_pubkey_hex) {
+    if (!message || !recipient_pubkeys || num_recipients <= 0 || !sender_pubkey_hex) {
+        return NULL;
+    }
+
+    // Create tags
+    cJSON* tags = create_dm_tags(recipient_pubkeys, num_recipients, subject,
+                               reply_to_event_id, reply_relay_url);
+    if (!tags) {
+        return NULL;
+    }
+
+    // Create the chat rumor (kind 14, unsigned)
+    cJSON* chat_event = nostr_nip59_create_rumor(14, message, tags, sender_pubkey_hex, 0);
+
+    cJSON_Delete(tags); // Tags are duplicated in create_rumor
+
+    return chat_event;
+}
+
+/**
+ * NIP-17: Create a file message event (kind 15)
+ */
+cJSON* nostr_nip17_create_file_event(const char* file_url,
+                                   const char* file_type,
+                                   const char* encryption_algorithm,
+                                   const char* decryption_key,
+                                   const char* decryption_nonce,
+                                   const char* file_hash,
+                                   const char* original_file_hash,
+                                   size_t file_size,
+                                   const char* dimensions,
+                                   const char* blurhash,
+                                   const char* thumbnail_url,
+                                   const char** recipient_pubkeys,
+                                   int num_recipients,
+                                   const char* subject,
+                                   const char* reply_to_event_id,
+                                   const char* reply_relay_url,
+                                   const char* sender_pubkey_hex) {
+    if (!file_url || !file_type || !encryption_algorithm || !decryption_key ||
+        !decryption_nonce || !file_hash || !recipient_pubkeys ||
+        num_recipients <= 0 || !sender_pubkey_hex) {
+        return NULL;
+    }
+
+    // Create base tags
+    cJSON* tags = create_dm_tags(recipient_pubkeys, num_recipients, subject,
+                               reply_to_event_id, reply_relay_url);
+    if (!tags) {
+        return NULL;
+    }
+
+    // Add file-specific tags
+    cJSON* file_type_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(file_type_tag, cJSON_CreateString("file-type"));
+    cJSON_AddItemToArray(file_type_tag, cJSON_CreateString(file_type));
+    cJSON_AddItemToArray(tags, file_type_tag);
+
+    cJSON* encryption_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(encryption_tag, cJSON_CreateString("encryption-algorithm"));
+    cJSON_AddItemToArray(encryption_tag, cJSON_CreateString(encryption_algorithm));
+    cJSON_AddItemToArray(tags, encryption_tag);
+
+    cJSON* key_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(key_tag, cJSON_CreateString("decryption-key"));
+    cJSON_AddItemToArray(key_tag, cJSON_CreateString(decryption_key));
+    cJSON_AddItemToArray(tags, key_tag);
+
+    cJSON* nonce_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(nonce_tag, cJSON_CreateString("decryption-nonce"));
+    cJSON_AddItemToArray(nonce_tag, cJSON_CreateString(decryption_nonce));
+    cJSON_AddItemToArray(tags, nonce_tag);
+
+    cJSON* x_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(x_tag, cJSON_CreateString("x"));
+    cJSON_AddItemToArray(x_tag, cJSON_CreateString(file_hash));
+    cJSON_AddItemToArray(tags, x_tag);
+
+    // Optional tags
+    if (original_file_hash && strlen(original_file_hash) > 0) {
+        cJSON* ox_tag = cJSON_CreateArray();
+        cJSON_AddItemToArray(ox_tag, cJSON_CreateString("ox"));
+        cJSON_AddItemToArray(ox_tag, cJSON_CreateString(original_file_hash));
+        cJSON_AddItemToArray(tags, ox_tag);
+    }
+
+    if (file_size > 0) {
+        char size_str[32];
+        snprintf(size_str, sizeof(size_str), "%zu", file_size);
+        cJSON* size_tag = cJSON_CreateArray();
+        cJSON_AddItemToArray(size_tag, cJSON_CreateString("size"));
+        cJSON_AddItemToArray(size_tag, cJSON_CreateString(size_str));
+        cJSON_AddItemToArray(tags, size_tag);
+    }
+
+    if (dimensions && strlen(dimensions) > 0) {
+        cJSON* dim_tag = cJSON_CreateArray();
+        cJSON_AddItemToArray(dim_tag, cJSON_CreateString("dim"));
+        cJSON_AddItemToArray(dim_tag, cJSON_CreateString(dimensions));
+        cJSON_AddItemToArray(tags, dim_tag);
+    }
+
+    if (blurhash && strlen(blurhash) > 0) {
+        cJSON* blurhash_tag = cJSON_CreateArray();
+        cJSON_AddItemToArray(blurhash_tag, cJSON_CreateString("blurhash"));
+        cJSON_AddItemToArray(blurhash_tag, cJSON_CreateString(blurhash));
+        cJSON_AddItemToArray(tags, blurhash_tag);
+    }
+
+    if (thumbnail_url && strlen(thumbnail_url) > 0) {
+        cJSON* thumb_tag = cJSON_CreateArray();
+        cJSON_AddItemToArray(thumb_tag, cJSON_CreateString("thumb"));
+        cJSON_AddItemToArray(thumb_tag, cJSON_CreateString(thumbnail_url));
+        cJSON_AddItemToArray(tags, thumb_tag);
+    }
+
+    // Create the file rumor (kind 15, unsigned)
+    cJSON* file_event = nostr_nip59_create_rumor(15, file_url, tags, sender_pubkey_hex, 0);
+
+    cJSON_Delete(tags); // Tags are duplicated in create_rumor
+
+    return file_event;
+}
+
+/**
+ * NIP-17: Create a relay list event (kind 10050)
+ */
+cJSON* nostr_nip17_create_relay_list_event(const char** relay_urls,
+                                         int num_relays,
+                                         const unsigned char* private_key) {
+    nostr_signer_t* signer;
+    cJSON* out;
+
+    if (!private_key) {
+        return NULL;
+    }
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) {
+        return NULL;
+    }
+
+    out = nostr_nip17_create_relay_list_event_with_signer(relay_urls, num_relays, signer);
+    nostr_signer_free(signer);
+    return out;
+}
+
+cJSON* nostr_nip17_create_relay_list_event_with_signer(const char** relay_urls,
+                                                      int num_relays,
+                                                      nostr_signer_t* signer) {
+    cJSON* tags;
+    cJSON* relay_event;
+
+    if (!relay_urls || num_relays <= 0 || !signer) {
+        return NULL;
+    }
+
+    tags = cJSON_CreateArray();
+    if (!tags) {
+        return NULL;
+    }
+
+    for (int i = 0; i < num_relays; i++) {
+        cJSON* relay_tag = cJSON_CreateArray();
+        if (!relay_tag) {
+            cJSON_Delete(tags);
+            return NULL;
+        }
+        cJSON_AddItemToArray(relay_tag, cJSON_CreateString("relay"));
+        cJSON_AddItemToArray(relay_tag, cJSON_CreateString(relay_urls[i]));
+        cJSON_AddItemToArray(tags, relay_tag);
+    }
+
+    relay_event = nostr_create_and_sign_event_with_signer(10050, "", tags, signer, time(NULL));
+    cJSON_Delete(tags);
+    return relay_event;
+}
+
+/**
+ * NIP-17: Send a direct message to recipients
+ */
+int nostr_nip17_send_dm(cJSON* dm_event,
+                        const char** recipient_pubkeys,
+                        int num_recipients,
+                        const unsigned char* sender_private_key,
+                        cJSON** gift_wraps_out,
+                        int max_gift_wraps,
+                        long max_delay_sec) {
+    nostr_signer_t* signer;
+    int out;
+
+    if (!sender_private_key) {
+        return -1;
+    }
+
+    signer = nostr_signer_local(sender_private_key);
+    if (!signer) {
+        return -1;
+    }
+
+    out = nostr_nip17_send_dm_with_signer(dm_event, recipient_pubkeys, num_recipients, signer,
+                                          gift_wraps_out, max_gift_wraps, max_delay_sec);
+    nostr_signer_free(signer);
+    return out;
+}
+
+int nostr_nip17_send_dm_with_signer(cJSON* dm_event,
+                                   const char** recipient_pubkeys,
+                                   int num_recipients,
+                                   nostr_signer_t* signer,
+                                   cJSON** gift_wraps_out,
+                                   int max_gift_wraps,
+                                   long max_delay_sec) {
+    int created_wraps = 0;
+    char sender_pubkey_hex[65];
+
+    if (!dm_event || !recipient_pubkeys || num_recipients <= 0 ||
+        !signer || !gift_wraps_out || max_gift_wraps <= 0) {
+        return -1;
+    }
+
+    for (int i = 0; i < num_recipients && created_wraps < max_gift_wraps; i++) {
+        unsigned char recipient_public_key[32];
+        if (nostr_hex_to_bytes(recipient_pubkeys[i], recipient_public_key, 32) != 0) {
+            continue;
+        }
+
+        cJSON* seal = nostr_nip59_create_seal_with_signer(dm_event, signer, recipient_public_key, max_delay_sec);
+        if (!seal) {
+            continue;
+        }
+
+        cJSON* gift_wrap = nostr_nip59_create_gift_wrap(seal, recipient_pubkeys[i], max_delay_sec);
+        cJSON_Delete(seal);
+
+        if (!gift_wrap) {
+            continue;
+        }
+
+        gift_wraps_out[created_wraps++] = gift_wrap;
+    }
+
+    if (created_wraps < max_gift_wraps && nostr_signer_get_public_key(signer, sender_pubkey_hex) == NOSTR_SUCCESS) {
+        unsigned char sender_public_key[32];
+        if (nostr_hex_to_bytes(sender_pubkey_hex, sender_public_key, 32) == 0) {
+            cJSON* sender_seal = nostr_nip59_create_seal_with_signer(dm_event, signer, sender_public_key, max_delay_sec);
+            if (sender_seal) {
+                cJSON* sender_gift_wrap = nostr_nip59_create_gift_wrap(sender_seal, sender_pubkey_hex, max_delay_sec);
+                cJSON_Delete(sender_seal);
+
+                if (sender_gift_wrap) {
+                    gift_wraps_out[created_wraps++] = sender_gift_wrap;
+                }
+            }
+        }
+    }
+
+    return created_wraps;
+}
+
+/**
+ * NIP-17: Receive and decrypt a direct message
+ */
+cJSON* nostr_nip17_receive_dm(cJSON* gift_wrap,
+                            const unsigned char* recipient_private_key) {
+    nostr_signer_t* signer;
+    cJSON* out;
+
+    if (!recipient_private_key) {
+        return NULL;
+    }
+
+    signer = nostr_signer_local(recipient_private_key);
+    if (!signer) {
+        return NULL;
+    }
+
+    out = nostr_nip17_receive_dm_with_signer(gift_wrap, signer);
+    nostr_signer_free(signer);
+    return out;
+}
+
+cJSON* nostr_nip17_receive_dm_with_signer(cJSON* gift_wrap,
+                                         nostr_signer_t* signer) {
+    cJSON* seal;
+    cJSON* seal_pubkey_item;
+    const char* sender_pubkey_hex;
+    unsigned char sender_public_key[32];
+    char sender_pubkey_hex_copy[65];
+    cJSON* rumor;
+    cJSON* rumor_pubkey_item;
+    const char* rumor_pubkey_hex;
+
+    if (!gift_wrap || !signer) {
+        return NULL;
+    }
+
+    seal = nostr_nip59_unwrap_gift_with_signer(gift_wrap, signer);
+    if (!seal) {
+        return NULL;
+    }
+
+    seal_pubkey_item = cJSON_GetObjectItem(seal, "pubkey");
+    if (!seal_pubkey_item || !cJSON_IsString(seal_pubkey_item)) {
+        cJSON_Delete(seal);
+        return NULL;
+    }
+
+    sender_pubkey_hex = cJSON_GetStringValue(seal_pubkey_item);
+    if (!sender_pubkey_hex || strlen(sender_pubkey_hex) != 64) {
+        cJSON_Delete(seal);
+        return NULL;
+    }
+    memcpy(sender_pubkey_hex_copy, sender_pubkey_hex, 65);
+    if (nostr_hex_to_bytes(sender_pubkey_hex_copy, sender_public_key, 32) != 0) {
+        cJSON_Delete(seal);
+        return NULL;
+    }
+
+    rumor = nostr_nip59_unseal_rumor_with_signer(seal, sender_public_key, signer);
+    cJSON_Delete(seal);
+    if (!rumor) {
+        return NULL;
+    }
+
+    rumor_pubkey_item = cJSON_GetObjectItem(rumor, "pubkey");
+    if (!rumor_pubkey_item || !cJSON_IsString(rumor_pubkey_item)) {
+        cJSON_Delete(rumor);
+        return NULL;
+    }
+
+    rumor_pubkey_hex = cJSON_GetStringValue(rumor_pubkey_item);
+    if (!rumor_pubkey_hex || strcmp(sender_pubkey_hex_copy, rumor_pubkey_hex) != 0) {
+        cJSON_Delete(rumor);
+        return NULL;
+    }
+
+    return rumor;
+}
+
+/**
+ * NIP-17: Extract DM relay URLs from a user's kind 10050 event
+ */
+int nostr_nip17_extract_dm_relays(cJSON* relay_list_event,
+                                char** relay_urls_out,
+                                int max_relays) {
+    if (!relay_list_event || !relay_urls_out || max_relays <= 0) {
+        return -1;
+    }
+
+    // Check if this is a kind 10050 event
+    cJSON* kind_item = cJSON_GetObjectItem(relay_list_event, "kind");
+    if (!kind_item || !cJSON_IsNumber(kind_item) || cJSON_GetNumberValue(kind_item) != 10050) {
+        return -1;
+    }
+
+    // Get tags array
+    cJSON* tags_item = cJSON_GetObjectItem(relay_list_event, "tags");
+    if (!tags_item || !cJSON_IsArray(tags_item)) {
+        return -1;
+    }
+
+    int extracted = 0;
+    cJSON* tag_item;
+    cJSON_ArrayForEach(tag_item, tags_item) {
+        if (!cJSON_IsArray(tag_item) || cJSON_GetArraySize(tag_item) < 2) {
+            continue;
+        }
+
+        // Check if this is a "relay" tag
+        cJSON* tag_name = cJSON_GetArrayItem(tag_item, 0);
+        cJSON* relay_url = cJSON_GetArrayItem(tag_item, 1);
+
+        if (cJSON_IsString(tag_name) && cJSON_IsString(relay_url) &&
+            strcmp(cJSON_GetStringValue(tag_name), "relay") == 0) {
+
+            if (extracted < max_relays) {
+                relay_urls_out[extracted] = strdup(cJSON_GetStringValue(relay_url));
+                if (relay_urls_out[extracted]) {
+                    extracted++;
+                }
+            }
+        }
+    }
+
+    return extracted;
+}

nostr_core/nip017.h

@@ -0,0 +1,152 @@
+/*
+ * NIP-17: Private Direct Messages
+ * https://github.com/nostr-protocol/nips/blob/master/17.md
+ */
+
+#ifndef NOSTR_NIP017_H
+#define NOSTR_NIP017_H
+
+#include <stddef.h>
+#include "nostr_signer.h"
+#include "../cjson/cJSON.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * NIP-17: Create a chat message event (kind 14)
+ *
+ * @param message Plain text message content
+ * @param recipient_pubkeys Array of recipient public keys (hex strings)
+ * @param num_recipients Number of recipients
+ * @param subject Optional conversation subject/title (can be NULL)
+ * @param reply_to_event_id Optional event ID this message replies to (can be NULL)
+ * @param reply_relay_url Optional relay URL for reply reference (can be NULL)
+ * @param sender_pubkey_hex Sender's public key in hex format
+ * @return cJSON object representing the unsigned chat event, or NULL on error
+ */
+cJSON* nostr_nip17_create_chat_event(const char* message,
+                                    const char** recipient_pubkeys,
+                                    int num_recipients,
+                                    const char* subject,
+                                    const char* reply_to_event_id,
+                                    const char* reply_relay_url,
+                                    const char* sender_pubkey_hex);
+
+/**
+ * NIP-17: Create a file message event (kind 15)
+ *
+ * @param file_url URL of the encrypted file
+ * @param file_type MIME type of the original file (e.g., "image/jpeg")
+ * @param encryption_algorithm Encryption algorithm used ("aes-gcm")
+ * @param decryption_key Base64-encoded decryption key
+ * @param decryption_nonce Base64-encoded decryption nonce
+ * @param file_hash SHA-256 hash of the encrypted file (hex)
+ * @param original_file_hash SHA-256 hash of the original file before encryption (hex, optional)
+ * @param file_size Size of encrypted file in bytes (optional, 0 to skip)
+ * @param dimensions Image dimensions in "WxH" format (optional, NULL to skip)
+ * @param blurhash Blurhash for preview (optional, NULL to skip)
+ * @param thumbnail_url URL of encrypted thumbnail (optional, NULL to skip)
+ * @param recipient_pubkeys Array of recipient public keys (hex strings)
+ * @param num_recipients Number of recipients
+ * @param subject Optional conversation subject/title (can be NULL)
+ * @param reply_to_event_id Optional event ID this message replies to (can be NULL)
+ * @param reply_relay_url Optional relay URL for reply reference (can be NULL)
+ * @param sender_pubkey_hex Sender's public key in hex format
+ * @return cJSON object representing the unsigned file event, or NULL on error
+ */
+cJSON* nostr_nip17_create_file_event(const char* file_url,
+                                   const char* file_type,
+                                   const char* encryption_algorithm,
+                                   const char* decryption_key,
+                                   const char* decryption_nonce,
+                                   const char* file_hash,
+                                   const char* original_file_hash,
+                                   size_t file_size,
+                                   const char* dimensions,
+                                   const char* blurhash,
+                                   const char* thumbnail_url,
+                                   const char** recipient_pubkeys,
+                                   int num_recipients,
+                                   const char* subject,
+                                   const char* reply_to_event_id,
+                                   const char* reply_relay_url,
+                                   const char* sender_pubkey_hex);
+
+/**
+ * NIP-17: Create a relay list event (kind 10050)
+ *
+ * @param relay_urls Array of relay URLs for DM delivery
+ * @param num_relays Number of relay URLs
+ * @param private_key Sender's private key for signing
+ * @return cJSON object representing the signed relay list event, or NULL on error
+ */
+cJSON* nostr_nip17_create_relay_list_event(const char** relay_urls,
+                                         int num_relays,
+                                         const unsigned char* private_key);
+cJSON* nostr_nip17_create_relay_list_event_with_signer(const char** relay_urls,
+                                                      int num_relays,
+                                                      nostr_signer_t* signer);
+
+/**
+ * NIP-17: Send a direct message to recipients
+ *
+ * This function creates the appropriate rumor, seals it, gift wraps it,
+ * and returns the final gift wrap events ready for publishing.
+ *
+ * @param dm_event The unsigned DM event (kind 14 or 15)
+ * @param recipient_pubkeys Array of recipient public keys (hex strings)
+ * @param num_recipients Number of recipients
+ * @param sender_private_key 32-byte sender private key
+ * @param gift_wraps_out Array to store resulting gift wrap events (caller must free)
+ * @param max_gift_wraps Maximum number of gift wraps to create
+ * @param max_delay_sec Maximum random timestamp delay in seconds (0 = no randomization)
+ * @return Number of gift wrap events created, or -1 on error
+ */
+int nostr_nip17_send_dm(cJSON* dm_event,
+                       const char** recipient_pubkeys,
+                       int num_recipients,
+                       const unsigned char* sender_private_key,
+                       cJSON** gift_wraps_out,
+                       int max_gift_wraps,
+                       long max_delay_sec);
+int nostr_nip17_send_dm_with_signer(cJSON* dm_event,
+                                   const char** recipient_pubkeys,
+                                   int num_recipients,
+                                   nostr_signer_t* signer,
+                                   cJSON** gift_wraps_out,
+                                   int max_gift_wraps,
+                                   long max_delay_sec);
+
+/**
+ * NIP-17: Receive and decrypt a direct message
+ *
+ * This function unwraps a gift wrap, unseals the rumor, and returns the original DM event.
+ *
+ * @param gift_wrap The received gift wrap event (kind 1059)
+ * @param recipient_private_key 32-byte recipient private key
+ * @return cJSON object representing the decrypted DM event, or NULL on error
+ */
+cJSON* nostr_nip17_receive_dm(cJSON* gift_wrap,
+                            const unsigned char* recipient_private_key);
+cJSON* nostr_nip17_receive_dm_with_signer(cJSON* gift_wrap,
+                                         nostr_signer_t* signer);
+
+/**
+ * NIP-17: Extract DM relay URLs from a user's kind 10050 event
+ *
+ * @param relay_list_event The kind 10050 event
+ * @param relay_urls_out Array to store extracted relay URLs (caller must free)
+ * @param max_relays Maximum number of relays to extract
+ * @return Number of relay URLs extracted, or -1 on error
+ */
+int nostr_nip17_extract_dm_relays(cJSON* relay_list_event,
+                                char** relay_urls_out,
+                                int max_relays);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // NOSTR_NIP017_H

nostr_core/nip019.c

@@ -180,7 +180,7 @@ nostr_input_type_t nostr_detect_input_type(const char* input) {
     if (len == 64) {
         int is_hex = 1;
         for (size_t i = 0; i < len; i++) {
-            if (!isxdigit(input[i])) {
+            if (!isxdigit((unsigned char)input[i])) {
                 is_hex = 0;
                 break;
             }

nostr_core/nip021.c

@@ -0,0 +1,855 @@
+/*
+ * NOSTR Core Library - NIP-021: nostr: URI scheme
+ */
+
+#include "nip021.h"
+#include "nip019.h"  // For existing bech32 functions
+#include "utils.h"
+#include "nostr_common.h"  // For error codes
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include "../cjson/cJSON.h"
+
+// Forward declarations for internal parsing functions
+static int parse_nprofile_data(const uint8_t* data, size_t data_len, nostr_nprofile_t* nprofile);
+static int parse_nevent_data(const uint8_t* data, size_t data_len, nostr_nevent_t* nevent);
+static int parse_naddr_data(const uint8_t* data, size_t data_len, nostr_naddr_t* naddr);
+
+// Bech32 constants and functions (copied from nip019.c for internal use)
+static const char bech32_charset[] = "qpzry9x8gf2tvdw0s3jn54khce6mua7l";
+static const int8_t bech32_charset_rev[128] = {
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    15, -1, 10, 17, 21, 20, 26, 30,  7,  5, -1, -1, -1, -1, -1, -1,
+    -1, 29, -1, 24, 13, 25,  9,  8, 23, -1, 18, 22, 31, 27, 19, -1,
+    1,  0,  3, 16, 11, 28, 12, 14,  6,  4,  2, -1, -1, -1, -1, -1,
+    -1, 29, -1, 24, 13, 25,  9,  8, 23, -1, 18, 22, 31, 27, 19, -1,
+    1,  0,  3, 16, 11, 28, 12, 14,  6,  4,  2, -1, -1, -1, -1, -1
+};
+
+static uint32_t bech32_polymod_step(uint32_t pre) {
+    uint8_t b = pre >> 25;
+    return ((pre & 0x1FFFFFF) << 5) ^
+           (-((b >> 0) & 1) & 0x3b6a57b2UL) ^
+           (-((b >> 1) & 1) & 0x26508e6dUL) ^
+           (-((b >> 2) & 1) & 0x1ea119faUL) ^
+           (-((b >> 3) & 1) & 0x3d4233ddUL) ^
+           (-((b >> 4) & 1) & 0x2a1462b3UL);
+}
+
+static int convert_bits(uint8_t *out, size_t *outlen, int outbits, const uint8_t *in, size_t inlen, int inbits, int pad) {
+    uint32_t val = 0;
+    int bits = 0;
+    uint32_t maxv = (((uint32_t)1) << outbits) - 1;
+    *outlen = 0;
+    while (inlen--) {
+        val = (val << inbits) | *(in++);
+        bits += inbits;
+        while (bits >= outbits) {
+            bits -= outbits;
+            out[(*outlen)++] = (val >> bits) & maxv;
+        }
+    }
+    if (pad) {
+        if (bits) {
+            out[(*outlen)++] = (val << (outbits - bits)) & maxv;
+        }
+    } else if (((val << (outbits - bits)) & maxv) || bits >= inbits) {
+        return 0;
+    }
+    return 1;
+}
+
+static int bech32_encode(char *output, const char *hrp, const uint8_t *data, size_t data_len) {
+    uint32_t chk = 1;
+    size_t i, hrp_len = strlen(hrp);
+
+    for (i = 0; i < hrp_len; ++i) {
+        int ch = hrp[i];
+        if (ch < 33 || ch > 126) return 0;
+        if (ch >= 'A' && ch <= 'Z') return 0;
+        chk = bech32_polymod_step(chk) ^ (ch >> 5);
+    }
+
+    chk = bech32_polymod_step(chk);
+    for (i = 0; i < hrp_len; ++i) {
+        chk = bech32_polymod_step(chk) ^ (hrp[i] & 0x1f);
+        *(output++) = hrp[i];
+    }
+
+    *(output++) = '1';
+    for (i = 0; i < data_len; ++i) {
+        if (*data >> 5) return 0;
+        chk = bech32_polymod_step(chk) ^ (*data);
+        *(output++) = bech32_charset[*(data++)];
+    }
+
+    for (i = 0; i < 6; ++i) {
+        chk = bech32_polymod_step(chk);
+    }
+
+    chk ^= 1;
+    for (i = 0; i < 6; ++i) {
+        *(output++) = bech32_charset[(chk >> ((5 - i) * 5)) & 0x1f];
+    }
+
+    *output = 0;
+    return 1;
+}
+
+static int bech32_decode(const char* input, const char* hrp, unsigned char* data, size_t* data_len) {
+    if (!input || !hrp || !data || !data_len) {
+        return 0;
+    }
+
+    size_t input_len = strlen(input);
+    size_t hrp_len = strlen(hrp);
+
+    if (input_len < hrp_len + 7) return 0;
+    if (strncmp(input, hrp, hrp_len) != 0) return 0;
+    if (input[hrp_len] != '1') return 0;
+
+    const char* data_part = input + hrp_len + 1;
+    size_t data_part_len = input_len - hrp_len - 1;
+
+    uint8_t values[256];
+    for (size_t i = 0; i < data_part_len; i++) {
+        unsigned char c = (unsigned char)data_part[i];
+        if (c >= 128) return 0;
+        int8_t val = bech32_charset_rev[c];
+        if (val == -1) return 0;
+        values[i] = (uint8_t)val;
+    }
+
+    if (data_part_len < 6) return 0;
+
+    uint32_t chk = 1;
+    for (size_t i = 0; i < hrp_len; i++) {
+        chk = bech32_polymod_step(chk) ^ (hrp[i] >> 5);
+    }
+    chk = bech32_polymod_step(chk);
+    for (size_t i = 0; i < hrp_len; i++) {
+        chk = bech32_polymod_step(chk) ^ (hrp[i] & 0x1f);
+    }
+    for (size_t i = 0; i < data_part_len; i++) {
+        chk = bech32_polymod_step(chk) ^ values[i];
+    }
+
+    if (chk != 1) return 0;
+
+    size_t payload_len = data_part_len - 6;
+    size_t decoded_len;
+    if (!convert_bits(data, &decoded_len, 8, values, payload_len, 5, 0)) {
+        return 0;
+    }
+
+    *data_len = decoded_len;
+    return 1;
+}
+
+// TLV (Type-Length-Value) constants for structured data
+#define TLV_SPECIAL 0
+#define TLV_RELAY 1
+#define TLV_AUTHOR 2
+#define TLV_KIND 3
+#define TLV_CREATED_AT 4
+#define TLV_IDENTIFIER 5
+
+// Forward declarations for internal functions
+static int tlv_encode(const uint8_t* data, size_t data_len, uint8_t type, uint8_t** output, size_t* output_len);
+static int encode_structured_bech32(const char* hrp, const uint8_t* data, size_t data_len, char* output, size_t output_size);
+static int decode_structured_bech32(const char* input, const char* expected_hrp, uint8_t** data, size_t* data_len);
+
+// Utility function to duplicate string array (removed - not used)
+
+// Free string array
+static void free_string_array(char** array, int count) {
+    if (!array) return;
+    for (int i = 0; i < count; i++) {
+        free(array[i]);
+    }
+    free(array);
+}
+
+// TLV encoding: Type (1 byte) + Length (1 byte) + Value
+static int tlv_encode(const uint8_t* data, size_t data_len, uint8_t type, uint8_t** output, size_t* output_len) {
+    if (data_len > 255) return 0; // Length must fit in 1 byte
+
+    *output_len = 2 + data_len;
+    *output = malloc(*output_len);
+    if (!*output) return 0;
+
+    (*output)[0] = type;
+    (*output)[1] = (uint8_t)data_len;
+    memcpy(*output + 2, data, data_len);
+    return 1;
+}
+
+// TLV decoding (removed - not used)
+
+// Encode structured data to bech32
+static int encode_structured_bech32(const char* hrp, const uint8_t* data, size_t data_len, char* output, size_t output_size) {
+    // For simple cases like note (32 bytes), use the existing key encoding
+    if (strcmp(hrp, "note") == 0 && data_len == 32) {
+        return nostr_key_to_bech32(data, "note", output);
+    }
+
+    uint8_t conv[256];
+    size_t conv_len;
+
+    if (!convert_bits(conv, &conv_len, 5, data, data_len, 8, 1)) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (!bech32_encode(output, hrp, conv, conv_len)) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (strlen(output) >= output_size) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+// Decode structured bech32 data
+static int decode_structured_bech32(const char* input, const char* expected_hrp, uint8_t** data, size_t* data_len) {
+    // bech32_decode already converts from 5-bit to 8-bit internally
+    *data = malloc(256);  // Max size
+    if (!*data) return NOSTR_ERROR_MEMORY_FAILED;
+
+    if (!bech32_decode(input, expected_hrp, *data, data_len)) {
+        free(*data);
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+// Detect URI type from string
+nostr_uri_type_t nostr_detect_uri_type(const char* uri) {
+    if (!uri) return NOSTR_URI_INVALID;
+
+    // Check for nostr: prefix
+    if (strncmp(uri, "nostr:", 6) != 0) {
+        return NOSTR_URI_INVALID;
+    }
+
+    const char* bech32_part = uri + 6;
+
+    // Check prefixes
+    if (strncmp(bech32_part, "npub1", 5) == 0) return NOSTR_URI_NPUB;
+    if (strncmp(bech32_part, "nsec1", 5) == 0) return NOSTR_URI_NSEC;
+    if (strncmp(bech32_part, "note1", 5) == 0) return NOSTR_URI_NOTE;
+    if (strncmp(bech32_part, "nprofile1", 9) == 0) return NOSTR_URI_NPROFILE;
+    if (strncmp(bech32_part, "nevent1", 7) == 0) return NOSTR_URI_NEVENT;
+    if (strncmp(bech32_part, "naddr1", 6) == 0) return NOSTR_URI_NADDR;
+
+    return NOSTR_URI_INVALID;
+}
+
+// Free URI result resources
+void nostr_uri_result_free(nostr_uri_result_t* result) {
+    if (!result) return;
+
+    switch (result->type) {
+        case NOSTR_URI_NPROFILE:
+            free_string_array(result->data.nprofile.relays, result->data.nprofile.relay_count);
+            break;
+        case NOSTR_URI_NEVENT:
+            free_string_array(result->data.nevent.relays, result->data.nevent.relay_count);
+            free(result->data.nevent.author);
+            free(result->data.nevent.kind);
+            free(result->data.nevent.created_at);
+            break;
+        case NOSTR_URI_NADDR:
+            free(result->data.naddr.identifier);
+            free_string_array(result->data.naddr.relays, result->data.naddr.relay_count);
+            break;
+        default:
+            break;
+    }
+}
+
+// Main URI parsing function
+int nostr_parse_uri(const char* uri, nostr_uri_result_t* result) {
+    if (!uri || !result) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    memset(result, 0, sizeof(nostr_uri_result_t));
+
+    nostr_uri_type_t type = nostr_detect_uri_type(uri);
+    if (type == NOSTR_URI_INVALID) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    const char* bech32_part = uri + 6; // Skip "nostr:"
+    result->type = type;
+
+    int ret;
+    switch (type) {
+        case NOSTR_URI_NPUB: {
+            ret = nostr_decode_npub(bech32_part, result->data.pubkey);
+            break;
+        }
+        case NOSTR_URI_NSEC: {
+            ret = nostr_decode_nsec(bech32_part, result->data.privkey);
+            break;
+        }
+        case NOSTR_URI_NOTE: {
+            // Note is similar to npub but with "note" prefix
+            uint8_t* decoded;
+            size_t decoded_len;
+            ret = decode_structured_bech32(bech32_part, "note", &decoded, &decoded_len);
+            if (ret == NOSTR_SUCCESS) {
+                if (decoded_len == 32) {
+                    memcpy(result->data.event_id, decoded, 32);
+                } else {
+                    ret = NOSTR_ERROR_INVALID_INPUT;
+                }
+                free(decoded);
+            }
+            break;
+        }
+        case NOSTR_URI_NPROFILE: {
+            uint8_t* decoded;
+            size_t decoded_len;
+            ret = decode_structured_bech32(bech32_part, "nprofile", &decoded, &decoded_len);
+            if (ret == NOSTR_SUCCESS) {
+                ret = parse_nprofile_data(decoded, decoded_len, &result->data.nprofile);
+                free(decoded);
+            }
+            break;
+        }
+        case NOSTR_URI_NEVENT: {
+            uint8_t* decoded;
+            size_t decoded_len;
+            ret = decode_structured_bech32(bech32_part, "nevent", &decoded, &decoded_len);
+            if (ret == NOSTR_SUCCESS) {
+                ret = parse_nevent_data(decoded, decoded_len, &result->data.nevent);
+                free(decoded);
+            }
+            break;
+        }
+        case NOSTR_URI_NADDR: {
+            uint8_t* decoded;
+            size_t decoded_len;
+            ret = decode_structured_bech32(bech32_part, "naddr", &decoded, &decoded_len);
+            if (ret == NOSTR_SUCCESS) {
+                ret = parse_naddr_data(decoded, decoded_len, &result->data.naddr);
+                free(decoded);
+            }
+            break;
+        }
+        default:
+            ret = NOSTR_ERROR_INVALID_INPUT;
+            break;
+    }
+
+    if (ret != NOSTR_SUCCESS) {
+        nostr_uri_result_free(result);
+        memset(result, 0, sizeof(nostr_uri_result_t));
+    }
+
+    return ret;
+}
+
+// Parse nprofile structured data
+static int parse_nprofile_data(const uint8_t* data, size_t data_len, nostr_nprofile_t* nprofile) {
+    size_t offset = 0;
+
+    while (offset < data_len) {
+        if (offset + 2 > data_len) return NOSTR_ERROR_INVALID_INPUT;
+
+        uint8_t type = data[offset];
+        uint8_t length = data[offset + 1];
+        offset += 2;
+
+        if (offset + length > data_len) return NOSTR_ERROR_INVALID_INPUT;
+
+        switch (type) {
+            case TLV_SPECIAL: // pubkey
+                if (length != 32) return NOSTR_ERROR_INVALID_INPUT;
+                memcpy(nprofile->pubkey, data + offset, 32);
+                break;
+            case TLV_RELAY: // relay URL
+                {
+                    char* relay = malloc(length + 1);
+                    if (!relay) return NOSTR_ERROR_MEMORY_FAILED;
+                    memcpy(relay, data + offset, length);
+                    relay[length] = '\0';
+
+                    char** new_relays = realloc(nprofile->relays, (nprofile->relay_count + 1) * sizeof(char*));
+                    if (!new_relays) {
+                        free(relay);
+                        return NOSTR_ERROR_MEMORY_FAILED;
+                    }
+                    nprofile->relays = new_relays;
+                    nprofile->relays[nprofile->relay_count++] = relay;
+                }
+                break;
+            default:
+                // Ignore unknown types
+                break;
+        }
+        offset += length;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+// Parse nevent structured data
+static int parse_nevent_data(const uint8_t* data, size_t data_len, nostr_nevent_t* nevent) {
+    size_t offset = 0;
+
+    while (offset < data_len) {
+        if (offset + 2 > data_len) return NOSTR_ERROR_INVALID_INPUT;
+
+        uint8_t type = data[offset];
+        uint8_t length = data[offset + 1];
+        offset += 2;
+
+        if (offset + length > data_len) return NOSTR_ERROR_INVALID_INPUT;
+
+        switch (type) {
+            case TLV_SPECIAL: // event ID
+                if (length != 32) return NOSTR_ERROR_INVALID_INPUT;
+                memcpy(nevent->event_id, data + offset, 32);
+                break;
+            case TLV_RELAY: // relay URL
+                {
+                    char* relay = malloc(length + 1);
+                    if (!relay) return NOSTR_ERROR_MEMORY_FAILED;
+                    memcpy(relay, data + offset, length);
+                    relay[length] = '\0';
+
+                    char** new_relays = realloc(nevent->relays, (nevent->relay_count + 1) * sizeof(char*));
+                    if (!new_relays) {
+                        free(relay);
+                        return NOSTR_ERROR_MEMORY_FAILED;
+                    }
+                    nevent->relays = new_relays;
+                    nevent->relays[nevent->relay_count++] = relay;
+                }
+                break;
+            case TLV_AUTHOR: // author pubkey
+                if (length != 32) return NOSTR_ERROR_INVALID_INPUT;
+                nevent->author = malloc(32);
+                if (!nevent->author) return NOSTR_ERROR_MEMORY_FAILED;
+                memcpy(nevent->author, data + offset, 32);
+                break;
+            case TLV_KIND: // kind
+                if (length != 4) return NOSTR_ERROR_INVALID_INPUT;
+                nevent->kind = malloc(sizeof(int));
+                if (!nevent->kind) return NOSTR_ERROR_MEMORY_FAILED;
+                *nevent->kind = (data[offset] << 24) | (data[offset+1] << 16) | (data[offset+2] << 8) | data[offset+3];
+                break;
+            case TLV_CREATED_AT: // created_at
+                if (length != 8) return NOSTR_ERROR_INVALID_INPUT;
+                nevent->created_at = malloc(sizeof(time_t));
+                if (!nevent->created_at) return NOSTR_ERROR_MEMORY_FAILED;
+                *nevent->created_at = ((time_t)data[offset] << 56) | ((time_t)data[offset+1] << 48) |
+                                     ((time_t)data[offset+2] << 40) | ((time_t)data[offset+3] << 32) |
+                                     ((time_t)data[offset+4] << 24) | ((time_t)data[offset+5] << 16) |
+                                     ((time_t)data[offset+6] << 8) | (time_t)data[offset+7];
+                break;
+            default:
+                // Ignore unknown types
+                break;
+        }
+        offset += length;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+// Parse naddr structured data
+static int parse_naddr_data(const uint8_t* data, size_t data_len, nostr_naddr_t* naddr) {
+    size_t offset = 0;
+
+    while (offset < data_len) {
+        if (offset + 2 > data_len) return NOSTR_ERROR_INVALID_INPUT;
+
+        uint8_t type = data[offset];
+        uint8_t length = data[offset + 1];
+        offset += 2;
+
+        if (offset + length > data_len) return NOSTR_ERROR_INVALID_INPUT;
+
+        switch (type) {
+            case TLV_IDENTIFIER: // identifier
+                naddr->identifier = malloc(length + 1);
+                if (!naddr->identifier) return NOSTR_ERROR_MEMORY_FAILED;
+                memcpy(naddr->identifier, data + offset, length);
+                naddr->identifier[length] = '\0';
+                break;
+            case TLV_SPECIAL: // pubkey
+                if (length != 32) return NOSTR_ERROR_INVALID_INPUT;
+                memcpy(naddr->pubkey, data + offset, 32);
+                break;
+            case TLV_KIND: // kind
+                if (length != 4) return NOSTR_ERROR_INVALID_INPUT;
+                naddr->kind = (data[offset] << 24) | (data[offset+1] << 16) | (data[offset+2] << 8) | data[offset+3];
+                break;
+            case TLV_RELAY: // relay URL
+                {
+                    char* relay = malloc(length + 1);
+                    if (!relay) return NOSTR_ERROR_MEMORY_FAILED;
+                    memcpy(relay, data + offset, length);
+                    relay[length] = '\0';
+
+                    char** new_relays = realloc(naddr->relays, (naddr->relay_count + 1) * sizeof(char*));
+                    if (!new_relays) {
+                        free(relay);
+                        return NOSTR_ERROR_MEMORY_FAILED;
+                    }
+                    naddr->relays = new_relays;
+                    naddr->relays[naddr->relay_count++] = relay;
+                }
+                break;
+            default:
+                // Ignore unknown types
+                break;
+        }
+        offset += length;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+
+// URI construction functions
+
+int nostr_build_uri_npub(const unsigned char* pubkey, char* output, size_t output_size) {
+    if (!pubkey || !output || output_size < 70) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    char bech32[100];
+    int ret = nostr_key_to_bech32(pubkey, "npub", bech32);
+    if (ret != NOSTR_SUCCESS) return ret;
+
+    size_t len = strlen(bech32);
+    if (len + 7 >= output_size) return NOSTR_ERROR_INVALID_INPUT;
+
+    strcpy(output, "nostr:");
+    strcpy(output + 6, bech32);
+    return NOSTR_SUCCESS;
+}
+
+int nostr_build_uri_nsec(const unsigned char* privkey, char* output, size_t output_size) {
+    if (!privkey || !output || output_size < 70) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    char bech32[100];
+    int ret = nostr_key_to_bech32(privkey, "nsec", bech32);
+    if (ret != NOSTR_SUCCESS) return ret;
+
+    size_t len = strlen(bech32);
+    if (len + 7 >= output_size) return NOSTR_ERROR_INVALID_INPUT;
+
+    strcpy(output, "nostr:");
+    strcpy(output + 6, bech32);
+    return NOSTR_SUCCESS;
+}
+
+// Helper to build URI with prefix
+static int build_uri_with_prefix(const char* bech32, char* output, size_t output_size) {
+    size_t len = strlen(bech32);
+    if (len + 7 >= output_size) return NOSTR_ERROR_INVALID_INPUT;
+
+    strcpy(output, "nostr:");
+    strcpy(output + 6, bech32);
+    return NOSTR_SUCCESS;
+}
+
+int nostr_build_uri_note(const unsigned char* event_id, char* output, size_t output_size) {
+    if (!event_id || !output || output_size < 70) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    char bech32[100];
+    int ret = encode_structured_bech32("note", event_id, 32, bech32, sizeof(bech32));
+    if (ret != NOSTR_SUCCESS) return ret;
+
+    return build_uri_with_prefix(bech32, output, output_size);
+}
+
+int nostr_build_uri_nprofile(const unsigned char* pubkey, const char** relays, int relay_count,
+                            char* output, size_t output_size) {
+    if (!pubkey || !output) return NOSTR_ERROR_INVALID_INPUT;
+
+    // Build TLV data
+    uint8_t* data = NULL;
+    size_t data_len = 0;
+
+    // Add pubkey (special)
+    uint8_t* pubkey_tlv;
+    size_t pubkey_tlv_len;
+    if (!tlv_encode(pubkey, 32, TLV_SPECIAL, &pubkey_tlv, &pubkey_tlv_len)) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    data = realloc(data, data_len + pubkey_tlv_len);
+    if (!data) {
+        free(pubkey_tlv);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    memcpy(data + data_len, pubkey_tlv, pubkey_tlv_len);
+    data_len += pubkey_tlv_len;
+    free(pubkey_tlv);
+
+    // Add relays
+    for (int i = 0; i < relay_count; i++) {
+        size_t relay_len = strlen(relays[i]);
+        uint8_t* relay_tlv;
+        size_t relay_tlv_len;
+        if (!tlv_encode((uint8_t*)relays[i], relay_len, TLV_RELAY, &relay_tlv, &relay_tlv_len)) {
+            free(data);
+            return NOSTR_ERROR_INVALID_INPUT;
+        }
+
+        data = realloc(data, data_len + relay_tlv_len);
+        if (!data) {
+            free(relay_tlv);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+        memcpy(data + data_len, relay_tlv, relay_tlv_len);
+        data_len += relay_tlv_len;
+        free(relay_tlv);
+    }
+
+    // Encode to bech32
+    char bech32[500];
+    int ret = encode_structured_bech32("nprofile", data, data_len, bech32, sizeof(bech32));
+    free(data);
+    if (ret != NOSTR_SUCCESS) return ret;
+
+    return build_uri_with_prefix(bech32, output, output_size);
+}
+
+int nostr_build_uri_nevent(const unsigned char* event_id, const char** relays, int relay_count,
+                          const unsigned char* author, int kind, time_t created_at,
+                          char* output, size_t output_size) {
+    if (!event_id || !output) return NOSTR_ERROR_INVALID_INPUT;
+
+    // Build TLV data
+    uint8_t* data = NULL;
+    size_t data_len = 0;
+
+    // Add event_id (special)
+    uint8_t* event_tlv;
+    size_t event_tlv_len;
+    if (!tlv_encode(event_id, 32, TLV_SPECIAL, &event_tlv, &event_tlv_len)) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    data = realloc(data, data_len + event_tlv_len);
+    if (!data) {
+        free(event_tlv);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    memcpy(data + data_len, event_tlv, event_tlv_len);
+    data_len += event_tlv_len;
+    free(event_tlv);
+
+    // Add relays
+    for (int i = 0; i < relay_count; i++) {
+        size_t relay_len = strlen(relays[i]);
+        uint8_t* relay_tlv;
+        size_t relay_tlv_len;
+        if (!tlv_encode((uint8_t*)relays[i], relay_len, TLV_RELAY, &relay_tlv, &relay_tlv_len)) {
+            free(data);
+            return NOSTR_ERROR_INVALID_INPUT;
+        }
+
+        data = realloc(data, data_len + relay_tlv_len);
+        if (!data) {
+            free(relay_tlv);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+        memcpy(data + data_len, relay_tlv, relay_tlv_len);
+        data_len += relay_tlv_len;
+        free(relay_tlv);
+    }
+
+    // Add author if provided
+    if (author) {
+        uint8_t* author_tlv;
+        size_t author_tlv_len;
+        if (!tlv_encode(author, 32, TLV_AUTHOR, &author_tlv, &author_tlv_len)) {
+            free(data);
+            return NOSTR_ERROR_INVALID_INPUT;
+        }
+
+        data = realloc(data, data_len + author_tlv_len);
+        if (!data) {
+            free(author_tlv);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+        memcpy(data + data_len, author_tlv, author_tlv_len);
+        data_len += author_tlv_len;
+        free(author_tlv);
+    }
+
+    // Add kind if provided
+    if (kind >= 0) {
+        uint8_t kind_bytes[4];
+        kind_bytes[0] = (kind >> 24) & 0xFF;
+        kind_bytes[1] = (kind >> 16) & 0xFF;
+        kind_bytes[2] = (kind >> 8) & 0xFF;
+        kind_bytes[3] = kind & 0xFF;
+
+        uint8_t* kind_tlv;
+        size_t kind_tlv_len;
+        if (!tlv_encode(kind_bytes, 4, TLV_KIND, &kind_tlv, &kind_tlv_len)) {
+            free(data);
+            return NOSTR_ERROR_INVALID_INPUT;
+        }
+
+        data = realloc(data, data_len + kind_tlv_len);
+        if (!data) {
+            free(kind_tlv);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+        memcpy(data + data_len, kind_tlv, kind_tlv_len);
+        data_len += kind_tlv_len;
+        free(kind_tlv);
+    }
+
+    // Add created_at if provided
+    if (created_at > 0) {
+        uint8_t time_bytes[8];
+        time_bytes[0] = (created_at >> 56) & 0xFF;
+        time_bytes[1] = (created_at >> 48) & 0xFF;
+        time_bytes[2] = (created_at >> 40) & 0xFF;
+        time_bytes[3] = (created_at >> 32) & 0xFF;
+        time_bytes[4] = (created_at >> 24) & 0xFF;
+        time_bytes[5] = (created_at >> 16) & 0xFF;
+        time_bytes[6] = (created_at >> 8) & 0xFF;
+        time_bytes[7] = created_at & 0xFF;
+
+        uint8_t* time_tlv;
+        size_t time_tlv_len;
+        if (!tlv_encode(time_bytes, 8, TLV_CREATED_AT, &time_tlv, &time_tlv_len)) {
+            free(data);
+            return NOSTR_ERROR_INVALID_INPUT;
+        }
+
+        data = realloc(data, data_len + time_tlv_len);
+        if (!data) {
+            free(time_tlv);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+        memcpy(data + data_len, time_tlv, time_tlv_len);
+        data_len += time_tlv_len;
+        free(time_tlv);
+    }
+
+    // Encode to bech32
+    char bech32[1000];
+    int ret = encode_structured_bech32("nevent", data, data_len, bech32, sizeof(bech32));
+    free(data);
+    if (ret != NOSTR_SUCCESS) return ret;
+
+    return build_uri_with_prefix(bech32, output, output_size);
+}
+
+int nostr_build_uri_naddr(const char* identifier, const unsigned char* pubkey, int kind,
+                         const char** relays, int relay_count, char* output, size_t output_size) {
+    if (!identifier || !pubkey || !output) return NOSTR_ERROR_INVALID_INPUT;
+
+    // Build TLV data
+    uint8_t* data = NULL;
+    size_t data_len = 0;
+
+    // Add identifier
+    size_t id_len = strlen(identifier);
+    uint8_t* id_tlv;
+    size_t id_tlv_len;
+    if (!tlv_encode((uint8_t*)identifier, id_len, TLV_IDENTIFIER, &id_tlv, &id_tlv_len)) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    data = realloc(data, data_len + id_tlv_len);
+    if (!data) {
+        free(id_tlv);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    memcpy(data + data_len, id_tlv, id_tlv_len);
+    data_len += id_tlv_len;
+    free(id_tlv);
+
+    // Add pubkey (special)
+    uint8_t* pubkey_tlv;
+    size_t pubkey_tlv_len;
+    if (!tlv_encode(pubkey, 32, TLV_SPECIAL, &pubkey_tlv, &pubkey_tlv_len)) {
+        free(data);
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    data = realloc(data, data_len + pubkey_tlv_len);
+    if (!data) {
+        free(pubkey_tlv);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    memcpy(data + data_len, pubkey_tlv, pubkey_tlv_len);
+    data_len += pubkey_tlv_len;
+    free(pubkey_tlv);
+
+    // Add kind
+    uint8_t kind_bytes[4];
+    kind_bytes[0] = (kind >> 24) & 0xFF;
+    kind_bytes[1] = (kind >> 16) & 0xFF;
+    kind_bytes[2] = (kind >> 8) & 0xFF;
+    kind_bytes[3] = kind & 0xFF;
+
+    uint8_t* kind_tlv;
+    size_t kind_tlv_len;
+    if (!tlv_encode(kind_bytes, 4, TLV_KIND, &kind_tlv, &kind_tlv_len)) {
+        free(data);
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    data = realloc(data, data_len + kind_tlv_len);
+    if (!data) {
+        free(kind_tlv);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    memcpy(data + data_len, kind_tlv, kind_tlv_len);
+    data_len += kind_tlv_len;
+    free(kind_tlv);
+
+    // Add relays
+    for (int i = 0; i < relay_count; i++) {
+        size_t relay_len = strlen(relays[i]);
+        uint8_t* relay_tlv;
+        size_t relay_tlv_len;
+        if (!tlv_encode((uint8_t*)relays[i], relay_len, TLV_RELAY, &relay_tlv, &relay_tlv_len)) {
+            free(data);
+            return NOSTR_ERROR_INVALID_INPUT;
+        }
+
+        data = realloc(data, data_len + relay_tlv_len);
+        if (!data) {
+            free(relay_tlv);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+        memcpy(data + data_len, relay_tlv, relay_tlv_len);
+        data_len += relay_tlv_len;
+        free(relay_tlv);
+    }
+
+    // Encode to bech32
+    char bech32[1000];
+    int ret = encode_structured_bech32("naddr", data, data_len, bech32, sizeof(bech32));
+    free(data);
+    if (ret != NOSTR_SUCCESS) return ret;
+
+    return build_uri_with_prefix(bech32, output, output_size);
+}

nostr_core/nip021.h

@@ -0,0 +1,81 @@
+/*
+ * NOSTR Core Library - NIP-021: nostr: URI scheme
+ */
+
+#ifndef NIP021_H
+#define NIP021_H
+
+#include <stdint.h>
+#include <time.h>
+#include "nip001.h"
+
+// URI type enumeration
+typedef enum {
+    NOSTR_URI_NPUB,      // Simple 32-byte pubkey
+    NOSTR_URI_NSEC,      // Simple 32-byte privkey
+    NOSTR_URI_NOTE,      // Simple 32-byte event ID
+    NOSTR_URI_NPROFILE,  // Structured: pubkey + relays
+    NOSTR_URI_NEVENT,    // Structured: event ID + relays + metadata
+    NOSTR_URI_NADDR,     // Structured: address + relays + metadata
+    NOSTR_URI_INVALID
+} nostr_uri_type_t;
+
+// Structured data types for complex URIs
+typedef struct {
+    unsigned char pubkey[32];
+    char** relays;
+    int relay_count;
+} nostr_nprofile_t;
+
+typedef struct {
+    unsigned char event_id[32];
+    char** relays;
+    int relay_count;
+    unsigned char* author;     // Optional, 32 bytes if present
+    int* kind;                 // Optional
+    time_t* created_at;        // Optional
+} nostr_nevent_t;
+
+typedef struct {
+    char* identifier;
+    unsigned char pubkey[32];
+    int kind;
+    char** relays;
+    int relay_count;
+} nostr_naddr_t;
+
+// Unified URI result structure
+typedef struct {
+    nostr_uri_type_t type;
+    union {
+        unsigned char pubkey[32];      // For NPUB
+        unsigned char privkey[32];     // For NSEC
+        unsigned char event_id[32];    // For NOTE
+        nostr_nprofile_t nprofile;      // For NPROFILE
+        nostr_nevent_t nevent;         // For NEVENT
+        nostr_naddr_t naddr;           // For NADDR
+    } data;
+} nostr_uri_result_t;
+
+// Function declarations
+
+// Main parsing function - unified entry point
+int nostr_parse_uri(const char* uri, nostr_uri_result_t* result);
+
+// URI construction functions
+int nostr_build_uri_npub(const unsigned char* pubkey, char* output, size_t output_size);
+int nostr_build_uri_nsec(const unsigned char* privkey, char* output, size_t output_size);
+int nostr_build_uri_note(const unsigned char* event_id, char* output, size_t output_size);
+int nostr_build_uri_nprofile(const unsigned char* pubkey, const char** relays, int relay_count,
+                            char* output, size_t output_size);
+int nostr_build_uri_nevent(const unsigned char* event_id, const char** relays, int relay_count,
+                          const unsigned char* author, int kind, time_t created_at,
+                          char* output, size_t output_size);
+int nostr_build_uri_naddr(const char* identifier, const unsigned char* pubkey, int kind,
+                         const char** relays, int relay_count, char* output, size_t output_size);
+
+// Utility functions
+void nostr_uri_result_free(nostr_uri_result_t* result);
+nostr_uri_type_t nostr_detect_uri_type(const char* uri);
+
+#endif // NIP021_H

nostr_core/nip042.c

@@ -0,0 +1,647 @@
+/*
+ * NOSTR Core Library - NIP-042: Authentication of clients to relays
+ * 
+ * Implements client authentication through signed ephemeral events
+ */
+
+#include "nip042.h"
+#include "nip001.h"
+#include "utils.h"
+#include "../cjson/cJSON.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+// Forward declarations for crypto functions
+int nostr_secp256k1_get_random_bytes(unsigned char* buf, size_t len);
+
+// =============================================================================
+// CLIENT-SIDE FUNCTIONS
+// =============================================================================
+
+/**
+ * Create NIP-42 authentication event (kind 22242)
+ */
+cJSON* nostr_nip42_create_auth_event_with_signer(const char* challenge,
+                                                 const char* relay_url,
+                                                 nostr_signer_t* signer,
+                                                 time_t timestamp) {
+    if (!challenge || !relay_url || !signer) {
+        return NULL;
+    }
+
+    // Validate challenge format
+    size_t challenge_len = strlen(challenge);
+    if (challenge_len < NOSTR_NIP42_MIN_CHALLENGE_LENGTH ||
+        challenge_len >= NOSTR_NIP42_MAX_CHALLENGE_LENGTH) {
+        return NULL;
+    }
+
+    // Create tags array with relay and challenge
+    cJSON* tags = cJSON_CreateArray();
+    if (!tags) {
+        return NULL;
+    }
+
+    // Add relay tag
+    cJSON* relay_tag = cJSON_CreateArray();
+    if (!relay_tag) {
+        cJSON_Delete(tags);
+        return NULL;
+    }
+    cJSON_AddItemToArray(relay_tag, cJSON_CreateString("relay"));
+    cJSON_AddItemToArray(relay_tag, cJSON_CreateString(relay_url));
+    cJSON_AddItemToArray(tags, relay_tag);
+
+    // Add challenge tag
+    cJSON* challenge_tag = cJSON_CreateArray();
+    if (!challenge_tag) {
+        cJSON_Delete(tags);
+        return NULL;
+    }
+    cJSON_AddItemToArray(challenge_tag, cJSON_CreateString("challenge"));
+    cJSON_AddItemToArray(challenge_tag, cJSON_CreateString(challenge));
+    cJSON_AddItemToArray(tags, challenge_tag);
+
+    cJSON* auth_event = nostr_create_and_sign_event_with_signer(
+        NOSTR_NIP42_AUTH_EVENT_KIND,
+        "",
+        tags,
+        signer,
+        timestamp
+    );
+
+    cJSON_Delete(tags);
+    return auth_event;
+}
+
+cJSON* nostr_nip42_create_auth_event(const char* challenge,
+                                      const char* relay_url,
+                                      const unsigned char* private_key,
+                                      time_t timestamp) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (!private_key) {
+        return NULL;
+    }
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) {
+        return NULL;
+    }
+
+    evt = nostr_nip42_create_auth_event_with_signer(challenge, relay_url, signer, timestamp);
+    nostr_signer_free(signer);
+    return evt;
+}
+
+/**
+ * Create AUTH message JSON for relay communication
+ */
+char* nostr_nip42_create_auth_message(cJSON* auth_event) {
+    if (!auth_event) {
+        return NULL;
+    }
+
+    // Create AUTH message array: ["AUTH", <event-json>]
+    cJSON* message_array = cJSON_CreateArray();
+    if (!message_array) {
+        return NULL;
+    }
+
+    cJSON_AddItemToArray(message_array, cJSON_CreateString("AUTH"));
+    cJSON_AddItemToArray(message_array, cJSON_Duplicate(auth_event, 1));
+
+    char* message_string = cJSON_PrintUnformatted(message_array);
+    cJSON_Delete(message_array);
+
+    return message_string;
+}
+
+/**
+ * Validate challenge string format and freshness
+ */
+int nostr_nip42_validate_challenge(const char* challenge, 
+                                   time_t received_at,
+                                   int time_tolerance) {
+    if (!challenge) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    size_t challenge_len = strlen(challenge);
+    
+    // Check challenge length
+    if (challenge_len < NOSTR_NIP42_MIN_CHALLENGE_LENGTH) {
+        return NOSTR_ERROR_NIP42_CHALLENGE_TOO_SHORT;
+    }
+    if (challenge_len >= NOSTR_NIP42_MAX_CHALLENGE_LENGTH) {
+        return NOSTR_ERROR_NIP42_CHALLENGE_TOO_LONG;
+    }
+
+    // Check time validity if provided
+    if (received_at > 0) {
+        time_t now = time(NULL);
+        int tolerance = (time_tolerance > 0) ? time_tolerance : NOSTR_NIP42_DEFAULT_TIME_TOLERANCE;
+        
+        if (now - received_at > tolerance) {
+            return NOSTR_ERROR_NIP42_CHALLENGE_EXPIRED;
+        }
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+/**
+ * Parse AUTH challenge message from relay
+ */
+int nostr_nip42_parse_auth_challenge(const char* message,
+                                     char* challenge_out,
+                                     size_t challenge_size) {
+    if (!message || !challenge_out || challenge_size == 0) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    cJSON* json = cJSON_Parse(message);
+    if (!json || !cJSON_IsArray(json)) {
+        if (json) cJSON_Delete(json);
+        return NOSTR_ERROR_NIP42_INVALID_MESSAGE_FORMAT;
+    }
+
+    // Check array has exactly 2 elements
+    if (cJSON_GetArraySize(json) != 2) {
+        cJSON_Delete(json);
+        return NOSTR_ERROR_NIP42_INVALID_MESSAGE_FORMAT;
+    }
+
+    // Check first element is "AUTH"
+    cJSON* message_type = cJSON_GetArrayItem(json, 0);
+    if (!message_type || !cJSON_IsString(message_type) || 
+        strcmp(cJSON_GetStringValue(message_type), "AUTH") != 0) {
+        cJSON_Delete(json);
+        return NOSTR_ERROR_NIP42_INVALID_MESSAGE_FORMAT;
+    }
+
+    // Get challenge string
+    cJSON* challenge_item = cJSON_GetArrayItem(json, 1);
+    if (!challenge_item || !cJSON_IsString(challenge_item)) {
+        cJSON_Delete(json);
+        return NOSTR_ERROR_NIP42_INVALID_MESSAGE_FORMAT;
+    }
+
+    const char* challenge_str = cJSON_GetStringValue(challenge_item);
+    if (!challenge_str || strlen(challenge_str) >= challenge_size) {
+        cJSON_Delete(json);
+        return NOSTR_ERROR_NIP42_INVALID_CHALLENGE;
+    }
+
+    strcpy(challenge_out, challenge_str);
+    cJSON_Delete(json);
+
+    return NOSTR_SUCCESS;
+}
+
+// =============================================================================
+// SERVER-SIDE FUNCTIONS
+// =============================================================================
+
+/**
+ * Generate cryptographically secure challenge string
+ */
+int nostr_nip42_generate_challenge(char* challenge_out, size_t length) {
+    if (!challenge_out || length < NOSTR_NIP42_MIN_CHALLENGE_LENGTH || 
+        length > NOSTR_NIP42_MAX_CHALLENGE_LENGTH / 2) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    // Generate random bytes
+    unsigned char random_bytes[NOSTR_NIP42_MAX_CHALLENGE_LENGTH / 2];
+    if (nostr_secp256k1_get_random_bytes(random_bytes, length) != 1) {
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    // Convert to hex string (reusing existing function)
+    nostr_bytes_to_hex(random_bytes, length, challenge_out);
+
+    return NOSTR_SUCCESS;
+}
+
+/**
+ * Verify NIP-42 authentication event
+ */
+int nostr_nip42_verify_auth_event(cJSON* auth_event,
+                                  const char* expected_challenge,
+                                  const char* relay_url,
+                                  int time_tolerance) {
+    if (!auth_event || !expected_challenge || !relay_url) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    // First validate basic event structure using existing function
+    int structure_result = nostr_validate_event_structure(auth_event);
+    if (structure_result != NOSTR_SUCCESS) {
+        return structure_result;
+    }
+
+    // Validate NIP-42 specific structure
+    int nip42_structure_result = nostr_nip42_validate_auth_event_structure(
+        auth_event, relay_url, expected_challenge, time_tolerance);
+    if (nip42_structure_result != NOSTR_SUCCESS) {
+        return nip42_structure_result;
+    }
+
+    // Finally verify cryptographic signature using existing function
+    return nostr_verify_event_signature(auth_event);
+}
+
+/**
+ * Parse AUTH message from client
+ */
+int nostr_nip42_parse_auth_message(const char* message, cJSON** auth_event_out) {
+    if (!message || !auth_event_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    cJSON* json = cJSON_Parse(message);
+    if (!json || !cJSON_IsArray(json)) {
+        if (json) cJSON_Delete(json);
+        return NOSTR_ERROR_NIP42_INVALID_MESSAGE_FORMAT;
+    }
+
+    // Check array has exactly 2 elements
+    if (cJSON_GetArraySize(json) != 2) {
+        cJSON_Delete(json);
+        return NOSTR_ERROR_NIP42_INVALID_MESSAGE_FORMAT;
+    }
+
+    // Check first element is "AUTH"
+    cJSON* message_type = cJSON_GetArrayItem(json, 0);
+    if (!message_type || !cJSON_IsString(message_type) || 
+        strcmp(cJSON_GetStringValue(message_type), "AUTH") != 0) {
+        cJSON_Delete(json);
+        return NOSTR_ERROR_NIP42_INVALID_MESSAGE_FORMAT;
+    }
+
+    // Get event object
+    cJSON* event_item = cJSON_GetArrayItem(json, 1);
+    if (!event_item || !cJSON_IsObject(event_item)) {
+        cJSON_Delete(json);
+        return NOSTR_ERROR_NIP42_INVALID_MESSAGE_FORMAT;
+    }
+
+    // Duplicate the event for the caller
+    *auth_event_out = cJSON_Duplicate(event_item, 1);
+    cJSON_Delete(json);
+
+    if (!*auth_event_out) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+/**
+ * Create "auth-required" error response
+ */
+char* nostr_nip42_create_auth_required_message(const char* subscription_id,
+                                               const char* event_id,
+                                               const char* reason) {
+    const char* default_reason = "authentication required";
+    const char* message_reason = reason ? reason : default_reason;
+
+    cJSON* response = cJSON_CreateArray();
+    if (!response) {
+        return NULL;
+    }
+
+    if (subscription_id) {
+        // CLOSED message for subscriptions
+        cJSON_AddItemToArray(response, cJSON_CreateString("CLOSED"));
+        cJSON_AddItemToArray(response, cJSON_CreateString(subscription_id));
+        
+        char prefix_message[512];
+        snprintf(prefix_message, sizeof(prefix_message), "auth-required: %s", message_reason);
+        cJSON_AddItemToArray(response, cJSON_CreateString(prefix_message));
+    } else if (event_id) {
+        // OK message for events
+        cJSON_AddItemToArray(response, cJSON_CreateString("OK"));
+        cJSON_AddItemToArray(response, cJSON_CreateString(event_id));
+        cJSON_AddItemToArray(response, cJSON_CreateBool(0)); // false
+        
+        char prefix_message[512];
+        snprintf(prefix_message, sizeof(prefix_message), "auth-required: %s", message_reason);
+        cJSON_AddItemToArray(response, cJSON_CreateString(prefix_message));
+    } else {
+        cJSON_Delete(response);
+        return NULL;
+    }
+
+    char* message_string = cJSON_PrintUnformatted(response);
+    cJSON_Delete(response);
+
+    return message_string;
+}
+
+/**
+ * Create "restricted" error response
+ */
+char* nostr_nip42_create_restricted_message(const char* subscription_id,
+                                            const char* event_id,
+                                            const char* reason) {
+    const char* default_reason = "access restricted";
+    const char* message_reason = reason ? reason : default_reason;
+
+    cJSON* response = cJSON_CreateArray();
+    if (!response) {
+        return NULL;
+    }
+
+    if (subscription_id) {
+        // CLOSED message for subscriptions
+        cJSON_AddItemToArray(response, cJSON_CreateString("CLOSED"));
+        cJSON_AddItemToArray(response, cJSON_CreateString(subscription_id));
+        
+        char prefix_message[512];
+        snprintf(prefix_message, sizeof(prefix_message), "restricted: %s", message_reason);
+        cJSON_AddItemToArray(response, cJSON_CreateString(prefix_message));
+    } else if (event_id) {
+        // OK message for events
+        cJSON_AddItemToArray(response, cJSON_CreateString("OK"));
+        cJSON_AddItemToArray(response, cJSON_CreateString(event_id));
+        cJSON_AddItemToArray(response, cJSON_CreateBool(0)); // false
+        
+        char prefix_message[512];
+        snprintf(prefix_message, sizeof(prefix_message), "restricted: %s", message_reason);
+        cJSON_AddItemToArray(response, cJSON_CreateString(prefix_message));
+    } else {
+        cJSON_Delete(response);
+        return NULL;
+    }
+
+    char* message_string = cJSON_PrintUnformatted(response);
+    cJSON_Delete(response);
+
+    return message_string;
+}
+
+// =============================================================================
+// URL NORMALIZATION FUNCTIONS
+// =============================================================================
+
+/**
+ * Normalize relay URL for comparison
+ */
+char* nostr_nip42_normalize_url(const char* url) {
+    if (!url) {
+        return NULL;
+    }
+
+    size_t url_len = strlen(url);
+    char* normalized = malloc(url_len + 1);
+    if (!normalized) {
+        return NULL;
+    }
+
+    strcpy(normalized, url);
+
+    // Remove trailing slash
+    if (url_len > 1 && normalized[url_len - 1] == '/') {
+        normalized[url_len - 1] = '\0';
+    }
+
+    // Convert to lowercase for domain comparison
+    for (size_t i = 0; normalized[i]; i++) {
+        if (normalized[i] >= 'A' && normalized[i] <= 'Z') {
+            normalized[i] = normalized[i] + ('a' - 'A');
+        }
+    }
+
+    return normalized;
+}
+
+/**
+ * Check if two relay URLs match after normalization
+ */
+int nostr_nip42_urls_match(const char* url1, const char* url2) {
+    if (!url1 || !url2) {
+        return -1;
+    }
+
+    char* norm1 = nostr_nip42_normalize_url(url1);
+    char* norm2 = nostr_nip42_normalize_url(url2);
+
+    if (!norm1 || !norm2) {
+        free(norm1);
+        free(norm2);
+        return -1;
+    }
+
+    int result = (strcmp(norm1, norm2) == 0) ? 1 : 0;
+
+    free(norm1);
+    free(norm2);
+
+    return result;
+}
+
+// =============================================================================
+// UTILITY FUNCTIONS
+// =============================================================================
+
+/**
+ * Get string description of authentication state
+ */
+const char* nostr_nip42_auth_state_str(nostr_auth_state_t state) {
+    switch (state) {
+        case NOSTR_AUTH_STATE_NONE:
+            return "none";
+        case NOSTR_AUTH_STATE_CHALLENGE_RECEIVED:
+            return "challenge_received";
+        case NOSTR_AUTH_STATE_AUTHENTICATING:
+            return "authenticating";
+        case NOSTR_AUTH_STATE_AUTHENTICATED:
+            return "authenticated";
+        case NOSTR_AUTH_STATE_REJECTED:
+            return "rejected";
+        default:
+            return "unknown";
+    }
+}
+
+/**
+ * Initialize authentication context structure
+ */
+int nostr_nip42_init_auth_context(nostr_auth_context_t* ctx,
+                                  const char* relay_url,
+                                  const char* challenge,
+                                  int time_tolerance) {
+    if (!ctx || !relay_url || !challenge) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    memset(ctx, 0, sizeof(nostr_auth_context_t));
+
+    ctx->relay_url = malloc(strlen(relay_url) + 1);
+    if (!ctx->relay_url) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    strcpy(ctx->relay_url, relay_url);
+
+    ctx->challenge = malloc(strlen(challenge) + 1);
+    if (!ctx->challenge) {
+        free(ctx->relay_url);
+        ctx->relay_url = NULL;
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    strcpy(ctx->challenge, challenge);
+
+    ctx->timestamp = time(NULL);
+    ctx->time_tolerance = (time_tolerance > 0) ? time_tolerance : NOSTR_NIP42_DEFAULT_TIME_TOLERANCE;
+
+    return NOSTR_SUCCESS;
+}
+
+/**
+ * Free authentication context structure
+ */
+void nostr_nip42_free_auth_context(nostr_auth_context_t* ctx) {
+    if (!ctx) {
+        return;
+    }
+
+    free(ctx->relay_url);
+    free(ctx->challenge);
+    free(ctx->pubkey_hex);
+
+    memset(ctx, 0, sizeof(nostr_auth_context_t));
+}
+
+/**
+ * Validate authentication event structure (without signature verification)
+ */
+int nostr_nip42_validate_auth_event_structure(cJSON* auth_event,
+                                              const char* relay_url,
+                                              const char* challenge,
+                                              int time_tolerance) {
+    if (!auth_event || !relay_url || !challenge) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    // Check event kind is 22242
+    cJSON* kind_item = cJSON_GetObjectItem(auth_event, "kind");
+    if (!kind_item || !cJSON_IsNumber(kind_item) || 
+        (int)cJSON_GetNumberValue(kind_item) != NOSTR_NIP42_AUTH_EVENT_KIND) {
+        return NOSTR_ERROR_NIP42_AUTH_EVENT_INVALID;
+    }
+
+    // Check timestamp is within tolerance
+    cJSON* created_at_item = cJSON_GetObjectItem(auth_event, "created_at");
+    if (!created_at_item || !cJSON_IsNumber(created_at_item)) {
+        return NOSTR_ERROR_EVENT_INVALID_CREATED_AT;
+    }
+
+    time_t event_time = (time_t)cJSON_GetNumberValue(created_at_item);
+    time_t now = time(NULL);
+    int tolerance = (time_tolerance > 0) ? time_tolerance : NOSTR_NIP42_DEFAULT_TIME_TOLERANCE;
+    
+    if (abs((int)(now - event_time)) > tolerance) {
+        return NOSTR_ERROR_NIP42_TIME_TOLERANCE;
+    }
+
+    // Check tags contain required relay and challenge
+    cJSON* tags_item = cJSON_GetObjectItem(auth_event, "tags");
+    if (!tags_item || !cJSON_IsArray(tags_item)) {
+        return NOSTR_ERROR_EVENT_INVALID_TAGS;
+    }
+
+    int found_relay = 0, found_challenge = 0;
+
+    cJSON* tag_item;
+    cJSON_ArrayForEach(tag_item, tags_item) {
+        if (!cJSON_IsArray(tag_item) || cJSON_GetArraySize(tag_item) < 2) {
+            continue;
+        }
+
+        cJSON* tag_name = cJSON_GetArrayItem(tag_item, 0);
+        cJSON* tag_value = cJSON_GetArrayItem(tag_item, 1);
+
+        if (!cJSON_IsString(tag_name) || !cJSON_IsString(tag_value)) {
+            continue;
+        }
+
+        const char* name = cJSON_GetStringValue(tag_name);
+        const char* value = cJSON_GetStringValue(tag_value);
+
+        if (strcmp(name, "relay") == 0) {
+            if (nostr_nip42_urls_match(value, relay_url) == 1) {
+                found_relay = 1;
+            }
+        } else if (strcmp(name, "challenge") == 0) {
+            if (strcmp(value, challenge) == 0) {
+                found_challenge = 1;
+            }
+        }
+    }
+
+    if (!found_relay) {
+        return NOSTR_ERROR_NIP42_URL_MISMATCH;
+    }
+
+    if (!found_challenge) {
+        return NOSTR_ERROR_NIP42_INVALID_CHALLENGE;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+// =============================================================================
+// WEBSOCKET CLIENT INTEGRATION STUB FUNCTIONS
+// =============================================================================
+// Note: These will need to be implemented when WebSocket client structure is available
+
+int nostr_ws_authenticate(struct nostr_ws_client* client,
+                         const unsigned char* private_key,
+                         int time_tolerance) {
+    // TODO: Implement when WebSocket client structure is available
+    (void)client;
+    (void)private_key;
+    (void)time_tolerance;
+    return NOSTR_ERROR_NETWORK_FAILED; // Placeholder
+}
+
+nostr_auth_state_t nostr_ws_get_auth_state(struct nostr_ws_client* client) {
+    // TODO: Implement when WebSocket client structure is available
+    (void)client;
+    return NOSTR_AUTH_STATE_NONE; // Placeholder
+}
+
+int nostr_ws_has_valid_challenge(struct nostr_ws_client* client) {
+    // TODO: Implement when WebSocket client structure is available
+    (void)client;
+    return 0; // Placeholder
+}
+
+int nostr_ws_get_challenge(struct nostr_ws_client* client,
+                          char* challenge_out,
+                          size_t challenge_size) {
+    // TODO: Implement when WebSocket client structure is available
+    (void)client;
+    (void)challenge_out;
+    (void)challenge_size;
+    return NOSTR_ERROR_NETWORK_FAILED; // Placeholder
+}
+
+int nostr_ws_store_challenge(struct nostr_ws_client* client,
+                            const char* challenge) {
+    // TODO: Implement when WebSocket client structure is available
+    (void)client;
+    (void)challenge;
+    return NOSTR_ERROR_NETWORK_FAILED; // Placeholder
+}
+
+int nostr_ws_clear_auth_state(struct nostr_ws_client* client) {
+    // TODO: Implement when WebSocket client structure is available
+    (void)client;
+    return NOSTR_ERROR_NETWORK_FAILED; // Placeholder
+}

nostr_core/nip042.h

@@ -0,0 +1,287 @@
+/*
+ * NOSTR Core Library - NIP-042: Authentication of clients to relays
+ * 
+ * Implements client authentication through signed ephemeral events
+ */
+
+#ifndef NIP042_H
+#define NIP042_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <time.h>
+#include "../cjson/cJSON.h"
+#include "nostr_common.h"
+#include "nostr_signer.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// =============================================================================
+// NIP-42 CONSTANTS AND DEFINITIONS
+// =============================================================================
+
+#define NOSTR_NIP42_AUTH_EVENT_KIND 22242
+#define NOSTR_NIP42_DEFAULT_CHALLENGE_LENGTH 32
+#define NOSTR_NIP42_DEFAULT_TIME_TOLERANCE 600  // 10 minutes in seconds
+#define NOSTR_NIP42_MAX_CHALLENGE_LENGTH 256
+#define NOSTR_NIP42_MIN_CHALLENGE_LENGTH 16
+
+// Authentication states for WebSocket client integration
+typedef enum {
+    NOSTR_AUTH_STATE_NONE = 0,               // No authentication attempted
+    NOSTR_AUTH_STATE_CHALLENGE_RECEIVED = 1,  // Challenge received from relay
+    NOSTR_AUTH_STATE_AUTHENTICATING = 2,      // AUTH event sent, waiting for OK
+    NOSTR_AUTH_STATE_AUTHENTICATED = 3,       // Successfully authenticated
+    NOSTR_AUTH_STATE_REJECTED = 4            // Authentication rejected
+} nostr_auth_state_t;
+
+// Challenge storage structure
+typedef struct {
+    char challenge[NOSTR_NIP42_MAX_CHALLENGE_LENGTH];
+    time_t received_at;
+    int is_valid;
+} nostr_auth_challenge_t;
+
+// Authentication context for relay verification
+typedef struct {
+    char* relay_url;
+    char* challenge;
+    time_t timestamp;
+    int time_tolerance;
+    char* pubkey_hex;
+} nostr_auth_context_t;
+
+// =============================================================================
+// CLIENT-SIDE FUNCTIONS (for nostr clients)
+// =============================================================================
+
+/**
+ * Create NIP-42 authentication event (kind 22242)
+ * @param challenge Challenge string received from relay
+ * @param relay_url Relay URL (normalized)
+ * @param private_key 32-byte private key for signing
+ * @param timestamp Event timestamp (0 for current time)
+ * @return cJSON event object or NULL on error
+ */
+cJSON* nostr_nip42_create_auth_event(const char* challenge,
+                                      const char* relay_url,
+                                      const unsigned char* private_key,
+                                      time_t timestamp);
+
+cJSON* nostr_nip42_create_auth_event_with_signer(const char* challenge,
+                                                 const char* relay_url,
+                                                 nostr_signer_t* signer,
+                                                 time_t timestamp);
+
+/**
+ * Create AUTH message JSON for relay communication
+ * @param auth_event Authentication event (kind 22242)
+ * @return JSON string for AUTH message or NULL on error (caller must free)
+ */
+char* nostr_nip42_create_auth_message(cJSON* auth_event);
+
+/**
+ * Validate challenge string format and freshness
+ * @param challenge Challenge string to validate
+ * @param received_at Time when challenge was received (0 for no time check)
+ * @param time_tolerance Maximum age in seconds (0 for default)
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_nip42_validate_challenge(const char* challenge, 
+                                   time_t received_at,
+                                   int time_tolerance);
+
+/**
+ * Parse AUTH challenge message from relay
+ * @param message Raw message from relay
+ * @param challenge_out Output buffer for challenge string
+ * @param challenge_size Size of challenge buffer
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_nip42_parse_auth_challenge(const char* message,
+                                     char* challenge_out,
+                                     size_t challenge_size);
+
+// =============================================================================
+// SERVER-SIDE FUNCTIONS (for relay implementations)
+// =============================================================================
+
+/**
+ * Generate cryptographically secure challenge string
+ * @param challenge_out Output buffer for challenge (must be at least length*2+1)
+ * @param length Desired challenge length in bytes (16-128)
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_nip42_generate_challenge(char* challenge_out, size_t length);
+
+/**
+ * Verify NIP-42 authentication event
+ * @param auth_event Authentication event to verify
+ * @param expected_challenge Challenge that was sent to client
+ * @param relay_url Expected relay URL
+ * @param time_tolerance Maximum timestamp deviation in seconds
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_nip42_verify_auth_event(cJSON* auth_event,
+                                  const char* expected_challenge,
+                                  const char* relay_url,
+                                  int time_tolerance);
+
+/**
+ * Parse AUTH message from client
+ * @param message Raw AUTH message from client
+ * @param auth_event_out Output pointer to parsed event (caller must free)
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_nip42_parse_auth_message(const char* message, cJSON** auth_event_out);
+
+/**
+ * Create "auth-required" error response
+ * @param subscription_id Subscription ID (for CLOSED) or NULL (for OK)
+ * @param event_id Event ID (for OK) or NULL (for CLOSED)
+ * @param reason Human-readable reason
+ * @return JSON string for response or NULL on error (caller must free)
+ */
+char* nostr_nip42_create_auth_required_message(const char* subscription_id,
+                                               const char* event_id,
+                                               const char* reason);
+
+/**
+ * Create "restricted" error response
+ * @param subscription_id Subscription ID (for CLOSED) or NULL (for OK)
+ * @param event_id Event ID (for OK) or NULL (for CLOSED)  
+ * @param reason Human-readable reason
+ * @return JSON string for response or NULL on error (caller must free)
+ */
+char* nostr_nip42_create_restricted_message(const char* subscription_id,
+                                            const char* event_id,
+                                            const char* reason);
+
+// =============================================================================
+// URL NORMALIZATION FUNCTIONS
+// =============================================================================
+
+/**
+ * Normalize relay URL for comparison (removes trailing slashes, etc.)
+ * @param url Original URL
+ * @return Normalized URL string or NULL on error (caller must free)
+ */
+char* nostr_nip42_normalize_url(const char* url);
+
+/**
+ * Check if two relay URLs match after normalization
+ * @param url1 First URL
+ * @param url2 Second URL  
+ * @return 1 if URLs match, 0 if they don't, -1 on error
+ */
+int nostr_nip42_urls_match(const char* url1, const char* url2);
+
+// =============================================================================
+// UTILITY FUNCTIONS
+// =============================================================================
+
+/**
+ * Get string description of authentication state
+ * @param state Authentication state
+ * @return Human-readable string
+ */
+const char* nostr_nip42_auth_state_str(nostr_auth_state_t state);
+
+/**
+ * Initialize authentication context structure
+ * @param ctx Context to initialize
+ * @param relay_url Relay URL
+ * @param challenge Challenge string
+ * @param time_tolerance Time tolerance in seconds
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_nip42_init_auth_context(nostr_auth_context_t* ctx,
+                                  const char* relay_url,
+                                  const char* challenge,
+                                  int time_tolerance);
+
+/**
+ * Free authentication context structure
+ * @param ctx Context to free
+ */
+void nostr_nip42_free_auth_context(nostr_auth_context_t* ctx);
+
+/**
+ * Validate authentication event structure (without signature verification)
+ * @param auth_event Event to validate
+ * @param relay_url Expected relay URL
+ * @param challenge Expected challenge
+ * @param time_tolerance Maximum timestamp deviation in seconds  
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_nip42_validate_auth_event_structure(cJSON* auth_event,
+                                              const char* relay_url,
+                                              const char* challenge,
+                                              int time_tolerance);
+
+// =============================================================================
+// WEBSOCKET CLIENT INTEGRATION
+// =============================================================================
+
+// Forward declaration for WebSocket client
+struct nostr_ws_client;
+
+/**
+ * Authenticate WebSocket client with relay
+ * @param client WebSocket client handle
+ * @param private_key 32-byte private key for authentication
+ * @param time_tolerance Maximum timestamp deviation in seconds (0 for default)
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_ws_authenticate(struct nostr_ws_client* client,
+                         const unsigned char* private_key,
+                         int time_tolerance);
+
+/**
+ * Get current authentication state of WebSocket client
+ * @param client WebSocket client handle
+ * @return Current authentication state
+ */
+nostr_auth_state_t nostr_ws_get_auth_state(struct nostr_ws_client* client);
+
+/**
+ * Check if WebSocket client has stored valid challenge
+ * @param client WebSocket client handle
+ * @return 1 if valid challenge exists, 0 otherwise
+ */
+int nostr_ws_has_valid_challenge(struct nostr_ws_client* client);
+
+/**
+ * Get stored challenge from WebSocket client
+ * @param client WebSocket client handle
+ * @param challenge_out Output buffer for challenge
+ * @param challenge_size Size of output buffer
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_ws_get_challenge(struct nostr_ws_client* client,
+                          char* challenge_out,
+                          size_t challenge_size);
+
+/**
+ * Store challenge in WebSocket client (internal function)
+ * @param client WebSocket client handle
+ * @param challenge Challenge string to store
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_ws_store_challenge(struct nostr_ws_client* client,
+                            const char* challenge);
+
+/**
+ * Clear authentication state in WebSocket client
+ * @param client WebSocket client handle
+ * @return NOSTR_SUCCESS or error code
+ */
+int nostr_ws_clear_auth_state(struct nostr_ws_client* client);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // NIP042_H

nostr_core/nip044.c

@@ -9,10 +9,29 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include "./crypto/nostr_secp256k1.h"
 
-// Include our ChaCha20 implementation
-#include "crypto/nostr_chacha20.h"
+// Forward declarations for crypto functions (private API)
+// These functions are implemented in crypto/ but not exposed through public headers
+int ecdh_shared_secret(const unsigned char* private_key, const unsigned char* public_key, unsigned char* shared_secret);
+int nostr_secp256k1_get_random_bytes(unsigned char* buf, size_t len);
+
+// ChaCha20 functions for NIP-44 encryption
+int chacha20_encrypt(const unsigned char key[32], unsigned int counter,
+                     const unsigned char nonce[12], const unsigned char* input,
+                     unsigned char* output, size_t length);
+
+// HKDF functions for NIP-44 key derivation
+int nostr_hkdf_extract(const unsigned char* salt, size_t salt_len,
+                       const unsigned char* ikm, size_t ikm_len,
+                       unsigned char* prk);
+int nostr_hkdf_expand(const unsigned char* prk, size_t prk_len,
+                      const unsigned char* info, size_t info_len,
+                      unsigned char* okm, size_t okm_len);
+
+// HMAC-SHA256 function for NIP-44 authentication
+int nostr_hmac_sha256(const unsigned char* key, size_t key_len,
+                      const unsigned char* data, size_t data_len,
+                      unsigned char* hmac);
 
 // Forward declarations for internal functions
 static size_t calc_padded_len(size_t unpadded_len);

nostr_core/nip044.h

@@ -13,7 +13,7 @@ extern "C" {
 #endif
 
 // NIP-44 constants
-// #define NOSTR_NIP44_MAX_PLAINTEXT_SIZE 65535
+// #define NOSTR_NIP44_MAX_PLAINTEXT_SIZE 1048576
 
 /**
  * NIP-44: Encrypt a message using ECDH + ChaCha20 + HMAC

nostr_core/nip046.h

@@ -0,0 +1,198 @@
+/*
+ * NIP-46: Nostr Remote Signing
+ * https://github.com/nostr-protocol/nips/blob/master/46.md
+ */
+
+#ifndef NOSTR_NIP046_H
+#define NOSTR_NIP046_H
+
+#include <stddef.h>
+#include <time.h>
+#include "nostr_common.h"
+#include "nip001.h"
+#include "nostr_signer.h"
+#include "../cjson/cJSON.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define NOSTR_NIP46_EVENT_KIND 24133
+#define NOSTR_NIP46_MAX_RELAYS 8
+#define NOSTR_NIP46_MAX_RELAY_URL_LEN 256
+#define NOSTR_NIP46_MAX_SECRET_LEN 128
+#define NOSTR_NIP46_MAX_REQUEST_ID_LEN 65
+#define NOSTR_NIP46_MAX_METHOD_LEN 32
+#define NOSTR_NIP46_MAX_URL_LEN 2048
+#define NOSTR_NIP46_MAX_PAYLOAD_LEN 65536
+
+typedef enum {
+    NOSTR_NIP46_CONN_BUNKER = 0,
+    NOSTR_NIP46_CONN_NOSTRCONNECT = 1
+} nostr_nip46_connection_type_t;
+
+typedef enum {
+    NOSTR_NIP46_METHOD_CONNECT = 0,
+    NOSTR_NIP46_METHOD_SIGN_EVENT,
+    NOSTR_NIP46_METHOD_PING,
+    NOSTR_NIP46_METHOD_GET_PUBLIC_KEY,
+    NOSTR_NIP46_METHOD_NIP04_ENCRYPT,
+    NOSTR_NIP46_METHOD_NIP04_DECRYPT,
+    NOSTR_NIP46_METHOD_NIP44_ENCRYPT,
+    NOSTR_NIP46_METHOD_NIP44_DECRYPT,
+    NOSTR_NIP46_METHOD_UNKNOWN
+} nostr_nip46_method_t;
+
+typedef struct {
+    char remote_signer_pubkey[65];
+    char relays[NOSTR_NIP46_MAX_RELAYS][NOSTR_NIP46_MAX_RELAY_URL_LEN];
+    int relay_count;
+    char secret[NOSTR_NIP46_MAX_SECRET_LEN];
+} nostr_nip46_bunker_url_t;
+
+typedef struct {
+    char client_pubkey[65];
+    char relays[NOSTR_NIP46_MAX_RELAYS][NOSTR_NIP46_MAX_RELAY_URL_LEN];
+    int relay_count;
+    char secret[NOSTR_NIP46_MAX_SECRET_LEN];
+    char perms[512];
+    char name[128];
+    char url[256];
+    char image[256];
+} nostr_nip46_nostrconnect_url_t;
+
+typedef struct {
+    char id[NOSTR_NIP46_MAX_REQUEST_ID_LEN];
+    nostr_nip46_method_t method;
+    char method_str[NOSTR_NIP46_MAX_METHOD_LEN];
+    char** params;
+    int param_count;
+} nostr_nip46_request_t;
+
+typedef struct {
+    char id[NOSTR_NIP46_MAX_REQUEST_ID_LEN];
+    char* result;
+    char* error;
+} nostr_nip46_response_t;
+
+typedef struct {
+    unsigned char client_private_key[32];
+    char client_pubkey_hex[65];
+    char remote_signer_pubkey_hex[65];
+    unsigned char remote_signer_pubkey[32];
+    char user_pubkey_hex[65];
+    char relays[NOSTR_NIP46_MAX_RELAYS][NOSTR_NIP46_MAX_RELAY_URL_LEN];
+    int relay_count;
+    int connected;
+    nostr_signer_t* client_signer;
+    int owns_client_signer;
+} nostr_nip46_client_session_t;
+
+typedef struct {
+    unsigned char signer_private_key[32];
+    char signer_pubkey_hex[65];
+    unsigned char user_private_key[32];
+    char user_pubkey_hex[65];
+    char client_pubkey_hex[65];
+    unsigned char client_pubkey[32];
+    char relays[NOSTR_NIP46_MAX_RELAYS][NOSTR_NIP46_MAX_RELAY_URL_LEN];
+    int relay_count;
+    int connected;
+} nostr_nip46_signer_session_t;
+
+/* URL parsing/creation */
+int nostr_nip46_parse_bunker_url(const char* url, nostr_nip46_bunker_url_t* out);
+int nostr_nip46_parse_nostrconnect_url(const char* url, nostr_nip46_nostrconnect_url_t* out);
+int nostr_nip46_create_bunker_url(const nostr_nip46_bunker_url_t* in, char* output, size_t output_size);
+int nostr_nip46_create_nostrconnect_url(const nostr_nip46_nostrconnect_url_t* in, char* output, size_t output_size);
+
+/* Method conversion */
+const char* nostr_nip46_method_to_string(nostr_nip46_method_t method);
+nostr_nip46_method_t nostr_nip46_string_to_method(const char* method);
+
+/* Request/response object utilities */
+int nostr_nip46_generate_request_id(char* output, size_t output_size);
+int nostr_nip46_create_request(const char* id,
+                               nostr_nip46_method_t method,
+                               const char** params,
+                               int param_count,
+                               nostr_nip46_request_t* out);
+int nostr_nip46_create_response(const char* id,
+                                const char* result,
+                                const char* error,
+                                nostr_nip46_response_t* out);
+int nostr_nip46_parse_request(const char* json_payload, nostr_nip46_request_t* out);
+int nostr_nip46_parse_response(const char* json_payload, nostr_nip46_response_t* out);
+void nostr_nip46_free_request(nostr_nip46_request_t* request);
+void nostr_nip46_free_response(nostr_nip46_response_t* response);
+
+/* JSON payload serialization */
+int nostr_nip46_request_to_json(const nostr_nip46_request_t* request, char** output_json);
+int nostr_nip46_response_to_json(const nostr_nip46_response_t* response, char** output_json);
+
+/* Event creation/decryption */
+cJSON* nostr_nip46_create_request_event(const nostr_nip46_request_t* request,
+                                        const unsigned char* sender_private_key,
+                                        const unsigned char* recipient_public_key,
+                                        time_t timestamp);
+cJSON* nostr_nip46_create_request_event_with_signer(const nostr_nip46_request_t* request,
+                                                    nostr_signer_t* signer,
+                                                    const unsigned char* recipient_public_key,
+                                                    time_t timestamp);
+cJSON* nostr_nip46_create_response_event(const nostr_nip46_response_t* response,
+                                         const unsigned char* sender_private_key,
+                                         const unsigned char* recipient_public_key,
+                                         time_t timestamp);
+cJSON* nostr_nip46_create_response_event_with_signer(const nostr_nip46_response_t* response,
+                                                     nostr_signer_t* signer,
+                                                     const unsigned char* recipient_public_key,
+                                                     time_t timestamp);
+int nostr_nip46_decrypt_event(cJSON* event,
+                              const unsigned char* recipient_private_key,
+                              char* output,
+                              size_t output_size);
+int nostr_nip46_decrypt_event_with_signer(cJSON* event,
+                                          nostr_signer_t* signer,
+                                          char** output_out);
+
+/* Client session */
+int nostr_nip46_client_session_init(nostr_nip46_client_session_t* session,
+                                    const unsigned char* client_private_key,
+                                    const char* bunker_url);
+int nostr_nip46_client_session_init_with_signer(nostr_nip46_client_session_t* session,
+                                                nostr_signer_t* signer,
+                                                const char* bunker_url);
+void nostr_nip46_client_session_destroy(nostr_nip46_client_session_t* session);
+
+int nostr_nip46_client_connect(nostr_nip46_client_session_t* session,
+                               const char* optional_secret,
+                               const char* optional_permissions,
+                               cJSON** request_event_out);
+int nostr_nip46_client_get_public_key(nostr_nip46_client_session_t* session,
+                                      cJSON** request_event_out);
+int nostr_nip46_client_ping(nostr_nip46_client_session_t* session,
+                            cJSON** request_event_out);
+int nostr_nip46_client_sign_event(nostr_nip46_client_session_t* session,
+                                  cJSON* unsigned_event,
+                                  cJSON** request_event_out);
+
+/* Signer session */
+int nostr_nip46_signer_session_init(nostr_nip46_signer_session_t* session,
+                                    const unsigned char* signer_private_key,
+                                    const unsigned char* user_private_key,
+                                    const char** relays,
+                                    int relay_count);
+void nostr_nip46_signer_session_destroy(nostr_nip46_signer_session_t* session);
+int nostr_nip46_signer_handle_request(nostr_nip46_signer_session_t* session,
+                                      const nostr_nip46_request_t* request,
+                                      nostr_nip46_response_t* response_out);
+int nostr_nip46_signer_create_bunker_url(const nostr_nip46_signer_session_t* session,
+                                         const char* optional_secret,
+                                         char* output,
+                                         size_t output_size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_NIP046_H */

nostr_core/nip059.c

@@ -0,0 +1,490 @@
+/*
+ * NIP-59: Gift Wrap Implementation
+ * https://github.com/nostr-protocol/nips/blob/master/59.md
+ */
+
+#include "nip059.h"
+#include "nip044.h"
+#include "nip001.h"
+#include "utils.h"
+#include "nostr_common.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+// Forward declarations for crypto functions
+int nostr_secp256k1_get_random_bytes(unsigned char* buf, size_t len);
+int nostr_ec_public_key_from_private_key(const unsigned char* private_key, unsigned char* public_key);
+int nostr_ec_sign(const unsigned char* private_key, const unsigned char* hash, unsigned char* signature);
+
+// Memory clearing utility
+static void memory_clear(const void *p, size_t len) {
+    if (p && len) {
+        memset((void *)p, 0, len);
+    }
+}
+
+/**
+ * Create a random timestamp within max_delay_sec in the past (configurable)
+ */
+static time_t random_past_timestamp(long max_delay_sec) {
+    time_t now = time(NULL);
+
+    // If max_delay_sec is 0, return current timestamp (no randomization)
+    if (max_delay_sec == 0) {
+        return now;
+    }
+
+    // Random time up to max_delay_sec in the past
+    long random_offset = (long)(rand() % max_delay_sec);
+    return now - random_offset;
+}
+
+/**
+ * NIP-44 padding calculation (mirrors nip044.c for output sizing)
+ */
+static size_t calc_nip44_padded_len(size_t unpadded_len) {
+    if (unpadded_len <= 32) {
+        return 32;
+    }
+
+    size_t next_power = 1;
+    while (next_power < unpadded_len) {
+        next_power <<= 1;
+    }
+
+    size_t chunk = (next_power <= 256) ? 32 : (next_power / 8);
+    return chunk * ((unpadded_len - 1) / chunk + 1);
+}
+
+/**
+ * Calculate safe output buffer size for NIP-44 encrypted base64 payload.
+ * Returns 0 if plaintext length exceeds NIP-44 max.
+ */
+static size_t calc_nip44_encrypted_b64_size(size_t plaintext_len) {
+    if (plaintext_len > NOSTR_NIP44_MAX_PLAINTEXT_SIZE) {
+        return 0;
+    }
+
+    size_t padded_len = calc_nip44_padded_len(plaintext_len) + 2;      // +2 for length prefix
+    size_t payload_len = 1 + 32 + padded_len + 32;                     // version + nonce + ciphertext + mac
+    size_t b64_len = ((payload_len + 2) / 3) * 4 + 1;                  // +1 for NUL terminator
+
+    return b64_len;
+}
+
+/**
+ * Generate a random private key for gift wrap
+ */
+static int generate_random_private_key(unsigned char* private_key) {
+    return nostr_secp256k1_get_random_bytes(private_key, 32);
+}
+
+/**
+ * Create event ID from event data (without signature)
+ */
+static int create_event_id(cJSON* event, char* event_id_hex) {
+    if (!event || !event_id_hex) {
+        return -1;
+    }
+
+    // Get event fields for serialization
+    cJSON* pubkey_item = cJSON_GetObjectItem(event, "pubkey");
+    cJSON* created_at_item = cJSON_GetObjectItem(event, "created_at");
+    cJSON* kind_item = cJSON_GetObjectItem(event, "kind");
+    cJSON* tags_item = cJSON_GetObjectItem(event, "tags");
+    cJSON* content_item = cJSON_GetObjectItem(event, "content");
+
+    if (!pubkey_item || !created_at_item || !kind_item || !tags_item || !content_item) {
+        return -1;
+    }
+
+    // Create serialization array: [0, pubkey, created_at, kind, tags, content]
+    cJSON* serialize_array = cJSON_CreateArray();
+    if (!serialize_array) {
+        return -1;
+    }
+
+    cJSON_AddItemToArray(serialize_array, cJSON_CreateNumber(0));
+    cJSON_AddItemToArray(serialize_array, cJSON_Duplicate(pubkey_item, 1));
+    cJSON_AddItemToArray(serialize_array, cJSON_Duplicate(created_at_item, 1));
+    cJSON_AddItemToArray(serialize_array, cJSON_Duplicate(kind_item, 1));
+    cJSON_AddItemToArray(serialize_array, cJSON_Duplicate(tags_item, 1));
+    cJSON_AddItemToArray(serialize_array, cJSON_Duplicate(content_item, 1));
+
+    char* serialize_string = cJSON_PrintUnformatted(serialize_array);
+    cJSON_Delete(serialize_array);
+
+    if (!serialize_string) {
+        return -1;
+    }
+
+    // Hash the serialized event
+    unsigned char event_hash[32];
+    if (nostr_sha256((const unsigned char*)serialize_string, strlen(serialize_string), event_hash) != 0) {
+        free(serialize_string);
+        return -1;
+    }
+
+    // Convert hash to hex
+    nostr_bytes_to_hex(event_hash, 32, event_id_hex);
+
+    free(serialize_string);
+    return 0;
+}
+
+/**
+ * NIP-59: Create a rumor (unsigned event)
+ */
+cJSON* nostr_nip59_create_rumor(int kind, const char* content, cJSON* tags,
+                               const char* pubkey_hex, time_t created_at) {
+    if (!pubkey_hex || !content) {
+        return NULL;
+    }
+
+    // Use provided timestamp or random past timestamp (default to 0 for compatibility)
+    time_t event_time = (created_at == 0) ? random_past_timestamp(0) : created_at;
+
+    // Create event structure (without id and sig - that's what makes it a rumor)
+    cJSON* rumor = cJSON_CreateObject();
+    if (!rumor) {
+        return NULL;
+    }
+
+    cJSON_AddStringToObject(rumor, "pubkey", pubkey_hex);
+    cJSON_AddNumberToObject(rumor, "created_at", (double)event_time);
+    cJSON_AddNumberToObject(rumor, "kind", kind);
+
+    // Add tags (copy provided tags or create empty array)
+    if (tags) {
+        cJSON_AddItemToObject(rumor, "tags", cJSON_Duplicate(tags, 1));
+    } else {
+        cJSON_AddItemToObject(rumor, "tags", cJSON_CreateArray());
+    }
+
+    cJSON_AddStringToObject(rumor, "content", content);
+
+    // Calculate and add event ID
+    char event_id[65];
+    if (create_event_id(rumor, event_id) != 0) {
+        cJSON_Delete(rumor);
+        return NULL;
+    }
+
+    cJSON_AddStringToObject(rumor, "id", event_id);
+
+    return rumor;
+}
+
+/**
+ * NIP-59: Create a seal (kind 13) wrapping a rumor
+ */
+cJSON* nostr_nip59_create_seal(cJSON* rumor, const unsigned char* sender_private_key,
+                               const unsigned char* recipient_public_key, long max_delay_sec) {
+    nostr_signer_t* signer;
+    cJSON* out;
+
+    if (!sender_private_key) {
+        return NULL;
+    }
+
+    signer = nostr_signer_local(sender_private_key);
+    if (!signer) {
+        return NULL;
+    }
+
+    out = nostr_nip59_create_seal_with_signer(rumor, signer, recipient_public_key, max_delay_sec);
+    nostr_signer_free(signer);
+    return out;
+}
+
+cJSON* nostr_nip59_create_seal_with_signer(cJSON* rumor, nostr_signer_t* signer,
+                                           const unsigned char* recipient_public_key, long max_delay_sec) {
+    cJSON* seal;
+    cJSON* signed_seal = NULL;
+    char* rumor_json;
+    char recipient_pubkey_hex[65];
+    char sender_pubkey_hex[65];
+    char* encrypted_content = NULL;
+    int rc;
+    time_t seal_time;
+
+    if (!rumor || !signer || !recipient_public_key) {
+        return NULL;
+    }
+
+    rumor_json = cJSON_PrintUnformatted(rumor);
+    if (!rumor_json) {
+        return NULL;
+    }
+
+    nostr_bytes_to_hex(recipient_public_key, 32, recipient_pubkey_hex);
+    rc = nostr_signer_nip44_encrypt(signer, recipient_pubkey_hex, rumor_json, &encrypted_content);
+    free(rumor_json);
+    if (rc != NOSTR_SUCCESS || !encrypted_content) {
+        free(encrypted_content);
+        return NULL;
+    }
+
+    rc = nostr_signer_get_public_key(signer, sender_pubkey_hex);
+    if (rc != NOSTR_SUCCESS) {
+        free(encrypted_content);
+        return NULL;
+    }
+
+    seal = cJSON_CreateObject();
+    if (!seal) {
+        free(encrypted_content);
+        return NULL;
+    }
+
+    seal_time = random_past_timestamp(max_delay_sec);
+    cJSON_AddStringToObject(seal, "pubkey", sender_pubkey_hex);
+    cJSON_AddNumberToObject(seal, "created_at", (double)seal_time);
+    cJSON_AddNumberToObject(seal, "kind", 13);
+    cJSON_AddItemToObject(seal, "tags", cJSON_CreateArray());
+    cJSON_AddStringToObject(seal, "content", encrypted_content);
+    free(encrypted_content);
+
+    rc = nostr_signer_sign_event(signer, seal, &signed_seal);
+    cJSON_Delete(seal);
+    if (rc != NOSTR_SUCCESS) {
+        cJSON_Delete(signed_seal);
+        return NULL;
+    }
+
+    return signed_seal;
+}
+
+/**
+ * NIP-59: Create a gift wrap (kind 1059) wrapping a seal
+ */
+cJSON* nostr_nip59_create_gift_wrap(cJSON* seal, const char* recipient_public_key_hex, long max_delay_sec) {
+    if (!seal || !recipient_public_key_hex) {
+        return NULL;
+    }
+
+    // Serialize the seal to JSON
+    char* seal_json = cJSON_PrintUnformatted(seal);
+    if (!seal_json) {
+        return NULL;
+    }
+
+    // Generate random private key for gift wrap
+    unsigned char random_private_key[32];
+    if (generate_random_private_key(random_private_key) != 1) {
+        free(seal_json);
+        return NULL;
+    }
+
+    // Get random public key
+    unsigned char random_public_key[32];
+    if (nostr_ec_public_key_from_private_key(random_private_key, random_public_key) != 0) {
+        memory_clear(random_private_key, 32);
+        free(seal_json);
+        return NULL;
+    }
+
+    char random_pubkey_hex[65];
+    nostr_bytes_to_hex(random_public_key, 32, random_pubkey_hex);
+
+    // Convert recipient pubkey hex to bytes
+    unsigned char recipient_public_key[32];
+    if (nostr_hex_to_bytes(recipient_public_key_hex, recipient_public_key, 32) != 0) {
+        memory_clear(random_private_key, 32);
+        free(seal_json);
+        return NULL;
+    }
+
+    // Encrypt the seal using NIP-44
+    size_t encrypted_size = calc_nip44_encrypted_b64_size(strlen(seal_json));
+    if (encrypted_size == 0) {
+        memory_clear(random_private_key, 32);
+        free(seal_json);
+        return NULL;
+    }
+
+    char* encrypted_content = malloc(encrypted_size);
+    if (!encrypted_content) {
+        memory_clear(random_private_key, 32);
+        free(seal_json);
+        return NULL;
+    }
+
+    int encrypt_result = nostr_nip44_encrypt(random_private_key, recipient_public_key,
+                                           seal_json, encrypted_content, encrypted_size);
+    free(seal_json);
+
+    if (encrypt_result != NOSTR_SUCCESS) {
+        memory_clear(random_private_key, 32);
+        free(encrypted_content);
+        return NULL;
+    }
+
+    // Create gift wrap event (kind 1059)
+    cJSON* gift_wrap = cJSON_CreateObject();
+    if (!gift_wrap) {
+        memory_clear(random_private_key, 32);
+        free(encrypted_content);
+        return NULL;
+    }
+
+    time_t wrap_time = random_past_timestamp(max_delay_sec);
+
+    cJSON_AddStringToObject(gift_wrap, "pubkey", random_pubkey_hex);
+    cJSON_AddNumberToObject(gift_wrap, "created_at", (double)wrap_time);
+    cJSON_AddNumberToObject(gift_wrap, "kind", 1059);
+
+    // Add p tag for recipient
+    cJSON* tags = cJSON_CreateArray();
+    cJSON* p_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(p_tag, cJSON_CreateString("p"));
+    cJSON_AddItemToArray(p_tag, cJSON_CreateString(recipient_public_key_hex));
+    cJSON_AddItemToArray(tags, p_tag);
+    cJSON_AddItemToObject(gift_wrap, "tags", tags);
+
+    cJSON_AddStringToObject(gift_wrap, "content", encrypted_content);
+    free(encrypted_content);
+
+    // Calculate event ID
+    char event_id[65];
+    if (create_event_id(gift_wrap, event_id) != 0) {
+        memory_clear(random_private_key, 32);
+        cJSON_Delete(gift_wrap);
+        return NULL;
+    }
+    cJSON_AddStringToObject(gift_wrap, "id", event_id);
+
+    // Sign the gift wrap
+    unsigned char event_hash[32];
+    if (nostr_hex_to_bytes(event_id, event_hash, 32) != 0) {
+        memory_clear(random_private_key, 32);
+        cJSON_Delete(gift_wrap);
+        return NULL;
+    }
+
+    unsigned char signature[64];
+    if (nostr_ec_sign(random_private_key, event_hash, signature) != 0) {
+        memory_clear(random_private_key, 32);
+        cJSON_Delete(gift_wrap);
+        return NULL;
+    }
+
+    char sig_hex[129];
+    nostr_bytes_to_hex(signature, 64, sig_hex);
+    cJSON_AddStringToObject(gift_wrap, "sig", sig_hex);
+
+    // Clear the random private key from memory
+    memory_clear(random_private_key, 32);
+
+    return gift_wrap;
+}
+
+/**
+ * NIP-59: Unwrap a gift wrap to get the seal
+ */
+cJSON* nostr_nip59_unwrap_gift(cJSON* gift_wrap, const unsigned char* recipient_private_key) {
+    nostr_signer_t* signer;
+    cJSON* out;
+
+    if (!recipient_private_key) {
+        return NULL;
+    }
+
+    signer = nostr_signer_local(recipient_private_key);
+    if (!signer) {
+        return NULL;
+    }
+
+    out = nostr_nip59_unwrap_gift_with_signer(gift_wrap, signer);
+    nostr_signer_free(signer);
+    return out;
+}
+
+cJSON* nostr_nip59_unwrap_gift_with_signer(cJSON* gift_wrap, nostr_signer_t* signer) {
+    cJSON* content_item;
+    cJSON* pubkey_item;
+    const char* encrypted_content;
+    const char* sender_pubkey_hex;
+    char* decrypted_json = NULL;
+    int rc;
+    cJSON* seal;
+
+    if (!gift_wrap || !signer) {
+        return NULL;
+    }
+
+    content_item = cJSON_GetObjectItem(gift_wrap, "content");
+    pubkey_item = cJSON_GetObjectItem(gift_wrap, "pubkey");
+    if (!content_item || !cJSON_IsString(content_item) || !pubkey_item || !cJSON_IsString(pubkey_item)) {
+        return NULL;
+    }
+
+    encrypted_content = cJSON_GetStringValue(content_item);
+    sender_pubkey_hex = cJSON_GetStringValue(pubkey_item);
+
+    rc = nostr_signer_nip44_decrypt(signer, sender_pubkey_hex, encrypted_content, &decrypted_json);
+    if (rc != NOSTR_SUCCESS || !decrypted_json) {
+        free(decrypted_json);
+        return NULL;
+    }
+
+    seal = cJSON_Parse(decrypted_json);
+    free(decrypted_json);
+    return seal;
+}
+
+/**
+ * NIP-59: Unseal a seal to get the rumor
+ */
+cJSON* nostr_nip59_unseal_rumor(cJSON* seal, const unsigned char* sender_public_key,
+                               const unsigned char* recipient_private_key) {
+    nostr_signer_t* signer;
+    cJSON* out;
+
+    if (!recipient_private_key) {
+        return NULL;
+    }
+
+    signer = nostr_signer_local(recipient_private_key);
+    if (!signer) {
+        return NULL;
+    }
+
+    out = nostr_nip59_unseal_rumor_with_signer(seal, sender_public_key, signer);
+    nostr_signer_free(signer);
+    return out;
+}
+
+cJSON* nostr_nip59_unseal_rumor_with_signer(cJSON* seal, const unsigned char* sender_public_key,
+                                            nostr_signer_t* signer) {
+    cJSON* content_item;
+    const char* encrypted_content;
+    char sender_pubkey_hex[65];
+    char* decrypted_json = NULL;
+    int rc;
+    cJSON* rumor;
+
+    if (!seal || !sender_public_key || !signer) {
+        return NULL;
+    }
+
+    content_item = cJSON_GetObjectItem(seal, "content");
+    if (!content_item || !cJSON_IsString(content_item)) {
+        return NULL;
+    }
+
+    encrypted_content = cJSON_GetStringValue(content_item);
+    nostr_bytes_to_hex(sender_public_key, 32, sender_pubkey_hex);
+
+    rc = nostr_signer_nip44_decrypt(signer, sender_pubkey_hex, encrypted_content, &decrypted_json);
+    if (rc != NOSTR_SUCCESS || !decrypted_json) {
+        free(decrypted_json);
+        return NULL;
+    }
+
+    rumor = cJSON_Parse(decrypted_json);
+    free(decrypted_json);
+    return rumor;
+}

nostr_core/nip059.h

@@ -0,0 +1,82 @@
+/*
+ * NIP-59: Gift Wrap
+ * https://github.com/nostr-protocol/nips/blob/master/59.md
+ */
+
+#ifndef NOSTR_NIP059_H
+#define NOSTR_NIP059_H
+
+#include <stddef.h>
+#include <time.h>
+#include "nostr_signer.h"
+#include "../cjson/cJSON.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * NIP-59: Create a rumor (unsigned event)
+ *
+ * @param kind Event kind
+ * @param content Event content
+ * @param tags Event tags (cJSON array, can be NULL)
+ * @param pubkey_hex Sender's public key in hex format
+ * @param created_at Event timestamp (0 for current time)
+ * @return cJSON object representing the rumor, or NULL on error
+ */
+cJSON* nostr_nip59_create_rumor(int kind, const char* content, cJSON* tags,
+                               const char* pubkey_hex, time_t created_at);
+
+/**
+ * NIP-59: Create a seal (kind 13) wrapping a rumor
+ *
+ * @param rumor The rumor event to seal (cJSON object)
+ * @param sender_private_key 32-byte sender private key
+ * @param recipient_public_key 32-byte recipient public key (x-only)
+ * @param max_delay_sec Maximum random timestamp delay in seconds (0 = no randomization)
+ * @return cJSON object representing the seal event, or NULL on error
+ */
+cJSON* nostr_nip59_create_seal(cJSON* rumor, const unsigned char* sender_private_key,
+                               const unsigned char* recipient_public_key, long max_delay_sec);
+cJSON* nostr_nip59_create_seal_with_signer(cJSON* rumor, nostr_signer_t* signer,
+                                           const unsigned char* recipient_public_key, long max_delay_sec);
+
+/**
+ * NIP-59: Create a gift wrap (kind 1059) wrapping a seal
+ *
+ * @param seal The seal event to wrap (cJSON object)
+ * @param recipient_public_key_hex Recipient's public key in hex format
+ * @param max_delay_sec Maximum random timestamp delay in seconds (0 = no randomization)
+ * @return cJSON object representing the gift wrap event, or NULL on error
+ */
+cJSON* nostr_nip59_create_gift_wrap(cJSON* seal, const char* recipient_public_key_hex, long max_delay_sec);
+
+/**
+ * NIP-59: Unwrap a gift wrap to get the seal
+ *
+ * @param gift_wrap The gift wrap event (cJSON object)
+ * @param recipient_private_key 32-byte recipient private key
+ * @return cJSON object representing the seal event, or NULL on error
+ */
+cJSON* nostr_nip59_unwrap_gift(cJSON* gift_wrap, const unsigned char* recipient_private_key);
+cJSON* nostr_nip59_unwrap_gift_with_signer(cJSON* gift_wrap, nostr_signer_t* signer);
+
+/**
+ * NIP-59: Unseal a seal to get the rumor
+ *
+ * @param seal The seal event (cJSON object)
+ * @param sender_public_key 32-byte sender public key (x-only)
+ * @param recipient_private_key 32-byte recipient private key
+ * @return cJSON object representing the rumor event, or NULL on error
+ */
+cJSON* nostr_nip59_unseal_rumor(cJSON* seal, const unsigned char* sender_public_key,
+                               const unsigned char* recipient_private_key);
+cJSON* nostr_nip59_unseal_rumor_with_signer(cJSON* seal, const unsigned char* sender_public_key,
+                                            nostr_signer_t* signer);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // NOSTR_NIP059_H

nostr_core/nip060.c

@@ -0,0 +1,936 @@
+/*
+ * NIP-60: Cashu Wallet Implementation
+ * https://github.com/nostr-protocol/nips/blob/master/60.md
+ */
+
+#include "nip060.h"
+#include "nip044.h"
+#include "utils.h"
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+int nostr_ec_public_key_from_private_key(const unsigned char* private_key, unsigned char* public_key);
+
+static char* nip60_strdup(const char* s) {
+    if (!s) return NULL;
+    size_t len = strlen(s);
+    char* out = (char*)malloc(len + 1);
+    if (!out) return NULL;
+    memcpy(out, s, len + 1);
+    return out;
+}
+
+static const char* nip60_marker_to_string(nostr_nip60_ref_marker_t marker) {
+    switch (marker) {
+        case NOSTR_NIP60_REF_CREATED: return "created";
+        case NOSTR_NIP60_REF_DESTROYED: return "destroyed";
+        case NOSTR_NIP60_REF_REDEEMED: return "redeemed";
+        default: return "created";
+    }
+}
+
+static nostr_nip60_ref_marker_t nip60_string_to_marker(const char* s) {
+    if (!s) return NOSTR_NIP60_REF_CREATED;
+    if (strcmp(s, "created") == 0) return NOSTR_NIP60_REF_CREATED;
+    if (strcmp(s, "destroyed") == 0) return NOSTR_NIP60_REF_DESTROYED;
+    if (strcmp(s, "redeemed") == 0) return NOSTR_NIP60_REF_REDEEMED;
+    return NOSTR_NIP60_REF_CREATED;
+}
+
+static const char* nip60_direction_to_string(nostr_nip60_direction_t direction) {
+    return (direction == NOSTR_NIP60_DIRECTION_OUT) ? "out" : "in";
+}
+
+static nostr_nip60_direction_t nip60_string_to_direction(const char* s) {
+    if (s && strcmp(s, "out") == 0) return NOSTR_NIP60_DIRECTION_OUT;
+    return NOSTR_NIP60_DIRECTION_IN;
+}
+
+static int nip60_encrypt_self_with_signer(nostr_signer_t* signer,
+                                          const char* plaintext,
+                                          char* output,
+                                          size_t output_size) {
+    if (!signer || !plaintext || !output || output_size == 0) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    char pubkey_hex[65];
+    int rc = nostr_signer_get_public_key(signer, pubkey_hex);
+    if (rc != NOSTR_SUCCESS) {
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    char* encrypted = NULL;
+    rc = nostr_signer_nip44_encrypt(signer, pubkey_hex, plaintext, &encrypted);
+    if (rc != NOSTR_SUCCESS || !encrypted) {
+        free(encrypted);
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    if (strlen(encrypted) + 1 > output_size) {
+        free(encrypted);
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    strcpy(output, encrypted);
+    free(encrypted);
+    return NOSTR_SUCCESS;
+}
+
+static int nip60_encrypt_self(const unsigned char* private_key,
+                              const char* plaintext,
+                              char* output,
+                              size_t output_size) {
+    nostr_signer_t* signer;
+    int rc;
+
+    if (!private_key) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) {
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    rc = nip60_encrypt_self_with_signer(signer, plaintext, output, output_size);
+    nostr_signer_free(signer);
+    return rc;
+}
+
+static int nip60_decrypt_event_content(cJSON* event,
+                                       const unsigned char* private_key,
+                                       char* output,
+                                       size_t output_size) {
+    if (!event || !private_key || !output || output_size == 0) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    cJSON* pubkey_item = cJSON_GetObjectItem(event, "pubkey");
+    cJSON* content_item = cJSON_GetObjectItem(event, "content");
+    if (!pubkey_item || !content_item || !cJSON_IsString(pubkey_item) || !cJSON_IsString(content_item)) {
+        return NOSTR_ERROR_NIP60_DECRYPT_FAILED;
+    }
+
+    const char* pubkey_hex = cJSON_GetStringValue(pubkey_item);
+    const char* content = cJSON_GetStringValue(content_item);
+    if (!pubkey_hex || !content) {
+        return NOSTR_ERROR_NIP60_DECRYPT_FAILED;
+    }
+
+    unsigned char sender_pubkey[32];
+    if (nostr_hex_to_bytes(pubkey_hex, sender_pubkey, 32) != 0) {
+        return NOSTR_ERROR_NIP60_DECRYPT_FAILED;
+    }
+
+    int rc = nostr_nip44_decrypt(private_key, sender_pubkey, content, output, output_size);
+    if (rc != NOSTR_SUCCESS) {
+        return NOSTR_ERROR_NIP60_DECRYPT_FAILED;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+uint64_t nostr_nip60_sum_proofs(const nostr_cashu_proof_t* proofs, int proof_count) {
+    if (!proofs || proof_count <= 0) return 0;
+
+    uint64_t total = 0;
+    for (int i = 0; i < proof_count; i++) {
+        total += proofs[i].amount;
+    }
+    return total;
+}
+
+void nostr_nip60_free_proofs(nostr_cashu_proof_t* proofs, int proof_count) {
+    if (!proofs) return;
+
+    for (int i = 0; i < proof_count; i++) {
+        free(proofs[i].secret);
+        free(proofs[i].C);
+        proofs[i].secret = NULL;
+        proofs[i].C = NULL;
+    }
+    free(proofs);
+}
+
+cJSON* nostr_nip60_proofs_to_json(const nostr_cashu_proof_t* proofs, int proof_count) {
+    if (!proofs || proof_count < 0) return NULL;
+
+    cJSON* arr = cJSON_CreateArray();
+    if (!arr) return NULL;
+
+    for (int i = 0; i < proof_count; i++) {
+        cJSON* obj = cJSON_CreateObject();
+        if (!obj) {
+            cJSON_Delete(arr);
+            return NULL;
+        }
+
+        cJSON_AddStringToObject(obj, "id", proofs[i].id);
+        cJSON_AddNumberToObject(obj, "amount", (double)proofs[i].amount);
+        cJSON_AddStringToObject(obj, "secret", proofs[i].secret ? proofs[i].secret : "");
+        cJSON_AddStringToObject(obj, "C", proofs[i].C ? proofs[i].C : "");
+        cJSON_AddItemToArray(arr, obj);
+    }
+
+    return arr;
+}
+
+int nostr_nip60_proofs_from_json(cJSON* json_array,
+                                 nostr_cashu_proof_t** proofs_out,
+                                 int* proof_count_out) {
+    if (!json_array || !cJSON_IsArray(json_array) || !proofs_out || !proof_count_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *proofs_out = NULL;
+    *proof_count_out = 0;
+
+    int count = cJSON_GetArraySize(json_array);
+    if (count <= 0) {
+        return NOSTR_SUCCESS;
+    }
+
+    nostr_cashu_proof_t* proofs = (nostr_cashu_proof_t*)calloc((size_t)count, sizeof(nostr_cashu_proof_t));
+    if (!proofs) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    for (int i = 0; i < count; i++) {
+        cJSON* p = cJSON_GetArrayItem(json_array, i);
+        if (!p || !cJSON_IsObject(p)) {
+            nostr_nip60_free_proofs(proofs, count);
+            return NOSTR_ERROR_NIP60_INVALID_PROOFS;
+        }
+
+        cJSON* id_item = cJSON_GetObjectItem(p, "id");
+        cJSON* amount_item = cJSON_GetObjectItem(p, "amount");
+        cJSON* secret_item = cJSON_GetObjectItem(p, "secret");
+        cJSON* c_item = cJSON_GetObjectItem(p, "C");
+
+        if (!id_item || !amount_item || !secret_item || !c_item ||
+            !cJSON_IsString(id_item) || !cJSON_IsNumber(amount_item) ||
+            !cJSON_IsString(secret_item) || !cJSON_IsString(c_item)) {
+            nostr_nip60_free_proofs(proofs, count);
+            return NOSTR_ERROR_NIP60_INVALID_PROOFS;
+        }
+
+        const char* id = cJSON_GetStringValue(id_item);
+        const char* secret = cJSON_GetStringValue(secret_item);
+        const char* C = cJSON_GetStringValue(c_item);
+        if (!id || !secret || !C) {
+            nostr_nip60_free_proofs(proofs, count);
+            return NOSTR_ERROR_NIP60_INVALID_PROOFS;
+        }
+
+        strncpy(proofs[i].id, id, sizeof(proofs[i].id) - 1);
+        proofs[i].id[sizeof(proofs[i].id) - 1] = '\0';
+        proofs[i].amount = (uint64_t)cJSON_GetNumberValue(amount_item);
+        proofs[i].secret = nip60_strdup(secret);
+        proofs[i].C = nip60_strdup(C);
+
+        if (!proofs[i].secret || !proofs[i].C) {
+            nostr_nip60_free_proofs(proofs, count);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+    }
+
+    *proofs_out = proofs;
+    *proof_count_out = count;
+    return NOSTR_SUCCESS;
+}
+
+cJSON* nostr_nip60_create_wallet_event_with_signer(const nostr_nip60_wallet_data_t* wallet_data,
+                                                   nostr_signer_t* signer,
+                                                   time_t timestamp) {
+    if (!wallet_data || !signer || wallet_data->mint_count <= 0) {
+        return NULL;
+    }
+
+    cJSON* payload = cJSON_CreateArray();
+    if (!payload) return NULL;
+
+    cJSON* priv_row = cJSON_CreateArray();
+    if (!priv_row) {
+        cJSON_Delete(payload);
+        return NULL;
+    }
+    cJSON_AddItemToArray(priv_row, cJSON_CreateString("privkey"));
+    cJSON_AddItemToArray(priv_row, cJSON_CreateString(wallet_data->privkey));
+    cJSON_AddItemToArray(payload, priv_row);
+
+    for (int i = 0; i < wallet_data->mint_count; i++) {
+        if (!wallet_data->mint_urls || !wallet_data->mint_urls[i]) continue;
+        cJSON* mint_row = cJSON_CreateArray();
+        if (!mint_row) {
+            cJSON_Delete(payload);
+            return NULL;
+        }
+        cJSON_AddItemToArray(mint_row, cJSON_CreateString("mint"));
+        cJSON_AddItemToArray(mint_row, cJSON_CreateString(wallet_data->mint_urls[i]));
+        cJSON_AddItemToArray(payload, mint_row);
+    }
+
+    char* plain = cJSON_PrintUnformatted(payload);
+    cJSON_Delete(payload);
+    if (!plain) return NULL;
+
+    char encrypted[65536];
+    int rc = nip60_encrypt_self_with_signer(signer, plain, encrypted, sizeof(encrypted));
+    free(plain);
+    if (rc != NOSTR_SUCCESS) return NULL;
+
+    return nostr_create_and_sign_event_with_signer(NOSTR_NIP60_WALLET_KIND, encrypted, NULL, signer, timestamp);
+}
+
+cJSON* nostr_nip60_create_wallet_event(const nostr_nip60_wallet_data_t* wallet_data,
+                                       const unsigned char* private_key,
+                                       time_t timestamp) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (!private_key) {
+        return NULL;
+    }
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) {
+        return NULL;
+    }
+
+    evt = nostr_nip60_create_wallet_event_with_signer(wallet_data, signer, timestamp);
+    nostr_signer_free(signer);
+    return evt;
+}
+
+int nostr_nip60_parse_wallet_event(cJSON* event,
+                                   const unsigned char* private_key,
+                                   nostr_nip60_wallet_data_t* wallet_data_out) {
+    if (!event || !private_key || !wallet_data_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    memset(wallet_data_out, 0, sizeof(*wallet_data_out));
+
+    cJSON* kind_item = cJSON_GetObjectItem(event, "kind");
+    if (!kind_item || !cJSON_IsNumber(kind_item) || (int)cJSON_GetNumberValue(kind_item) != NOSTR_NIP60_WALLET_KIND) {
+        return NOSTR_ERROR_NIP60_INVALID_WALLET;
+    }
+
+    char decrypted[65536];
+    int rc = nip60_decrypt_event_content(event, private_key, decrypted, sizeof(decrypted));
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    cJSON* payload = cJSON_Parse(decrypted);
+    if (!payload || !cJSON_IsArray(payload)) {
+        cJSON_Delete(payload);
+        return NOSTR_ERROR_NIP60_INVALID_WALLET;
+    }
+
+    int mint_count = 0;
+    cJSON* row = NULL;
+    cJSON_ArrayForEach(row, payload) {
+        if (!cJSON_IsArray(row) || cJSON_GetArraySize(row) < 2) continue;
+        cJSON* k = cJSON_GetArrayItem(row, 0);
+        cJSON* v = cJSON_GetArrayItem(row, 1);
+        if (!k || !v || !cJSON_IsString(k) || !cJSON_IsString(v)) continue;
+        const char* key = cJSON_GetStringValue(k);
+        if (key && strcmp(key, "mint") == 0) mint_count++;
+    }
+
+    if (mint_count > 0) {
+        wallet_data_out->mint_urls = (char**)calloc((size_t)mint_count, sizeof(char*));
+        if (!wallet_data_out->mint_urls) {
+            cJSON_Delete(payload);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+    }
+
+    int mint_idx = 0;
+    cJSON_ArrayForEach(row, payload) {
+        if (!cJSON_IsArray(row) || cJSON_GetArraySize(row) < 2) continue;
+        cJSON* k = cJSON_GetArrayItem(row, 0);
+        cJSON* v = cJSON_GetArrayItem(row, 1);
+        if (!k || !v || !cJSON_IsString(k) || !cJSON_IsString(v)) continue;
+
+        const char* key = cJSON_GetStringValue(k);
+        const char* val = cJSON_GetStringValue(v);
+        if (!key || !val) continue;
+
+        if (strcmp(key, "privkey") == 0) {
+            strncpy(wallet_data_out->privkey, val, sizeof(wallet_data_out->privkey) - 1);
+            wallet_data_out->privkey[sizeof(wallet_data_out->privkey) - 1] = '\0';
+        } else if (strcmp(key, "mint") == 0 && mint_idx < mint_count) {
+            wallet_data_out->mint_urls[mint_idx] = nip60_strdup(val);
+            if (!wallet_data_out->mint_urls[mint_idx]) {
+                cJSON_Delete(payload);
+                nostr_nip60_free_wallet_data(wallet_data_out);
+                return NOSTR_ERROR_MEMORY_FAILED;
+            }
+            mint_idx++;
+        }
+    }
+
+    wallet_data_out->mint_count = mint_idx;
+    cJSON_Delete(payload);
+
+    if (wallet_data_out->privkey[0] == '\0' || wallet_data_out->mint_count == 0) {
+        nostr_nip60_free_wallet_data(wallet_data_out);
+        return NOSTR_ERROR_NIP60_INVALID_WALLET;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+void nostr_nip60_free_wallet_data(nostr_nip60_wallet_data_t* data) {
+    if (!data) return;
+    if (data->mint_urls) {
+        for (int i = 0; i < data->mint_count; i++) {
+            free(data->mint_urls[i]);
+        }
+        free(data->mint_urls);
+    }
+    memset(data, 0, sizeof(*data));
+}
+
+cJSON* nostr_nip60_create_token_event_with_signer(const nostr_nip60_token_data_t* token_data,
+                                                  nostr_signer_t* signer,
+                                                  time_t timestamp) {
+    if (!token_data || !signer || !token_data->mint_url ||
+        !token_data->proofs || token_data->proof_count <= 0) {
+        return NULL;
+    }
+
+    cJSON* payload = cJSON_CreateObject();
+    if (!payload) return NULL;
+
+    cJSON_AddStringToObject(payload, "mint", token_data->mint_url);
+
+    cJSON* proofs = nostr_nip60_proofs_to_json(token_data->proofs, token_data->proof_count);
+    if (!proofs) {
+        cJSON_Delete(payload);
+        return NULL;
+    }
+    cJSON_AddItemToObject(payload, "proofs", proofs);
+
+    if (token_data->deleted_token_ids && token_data->deleted_count > 0) {
+        cJSON* del = cJSON_CreateArray();
+        if (!del) {
+            cJSON_Delete(payload);
+            return NULL;
+        }
+        for (int i = 0; i < token_data->deleted_count; i++) {
+            if (token_data->deleted_token_ids[i]) {
+                cJSON_AddItemToArray(del, cJSON_CreateString(token_data->deleted_token_ids[i]));
+            }
+        }
+        cJSON_AddItemToObject(payload, "del", del);
+    }
+
+    char* plain = cJSON_PrintUnformatted(payload);
+    cJSON_Delete(payload);
+    if (!plain) return NULL;
+
+    char encrypted[131072];
+    int rc = nip60_encrypt_self_with_signer(signer, plain, encrypted, sizeof(encrypted));
+    free(plain);
+    if (rc != NOSTR_SUCCESS) return NULL;
+
+    return nostr_create_and_sign_event_with_signer(NOSTR_NIP60_TOKEN_KIND, encrypted, NULL, signer, timestamp);
+}
+
+cJSON* nostr_nip60_create_token_event(const nostr_nip60_token_data_t* token_data,
+                                      const unsigned char* private_key,
+                                      time_t timestamp) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (!private_key) {
+        return NULL;
+    }
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) {
+        return NULL;
+    }
+
+    evt = nostr_nip60_create_token_event_with_signer(token_data, signer, timestamp);
+    nostr_signer_free(signer);
+    return evt;
+}
+
+int nostr_nip60_parse_token_event(cJSON* event,
+                                  const unsigned char* private_key,
+                                  nostr_nip60_token_data_t* token_data_out) {
+    if (!event || !private_key || !token_data_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    memset(token_data_out, 0, sizeof(*token_data_out));
+
+    cJSON* kind_item = cJSON_GetObjectItem(event, "kind");
+    if (!kind_item || !cJSON_IsNumber(kind_item) || (int)cJSON_GetNumberValue(kind_item) != NOSTR_NIP60_TOKEN_KIND) {
+        return NOSTR_ERROR_NIP60_INVALID_TOKEN;
+    }
+
+    char decrypted[131072];
+    int rc = nip60_decrypt_event_content(event, private_key, decrypted, sizeof(decrypted));
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    cJSON* payload = cJSON_Parse(decrypted);
+    if (!payload || !cJSON_IsObject(payload)) {
+        cJSON_Delete(payload);
+        return NOSTR_ERROR_NIP60_INVALID_TOKEN;
+    }
+
+    cJSON* mint_item = cJSON_GetObjectItem(payload, "mint");
+    cJSON* proofs_item = cJSON_GetObjectItem(payload, "proofs");
+    if (!mint_item || !proofs_item || !cJSON_IsString(mint_item) || !cJSON_IsArray(proofs_item)) {
+        cJSON_Delete(payload);
+        return NOSTR_ERROR_NIP60_INVALID_TOKEN;
+    }
+
+    const char* mint_url = cJSON_GetStringValue(mint_item);
+    token_data_out->mint_url = nip60_strdup(mint_url ? mint_url : "");
+    if (!token_data_out->mint_url) {
+        cJSON_Delete(payload);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    rc = nostr_nip60_proofs_from_json(proofs_item, &token_data_out->proofs, &token_data_out->proof_count);
+    if (rc != NOSTR_SUCCESS) {
+        cJSON_Delete(payload);
+        nostr_nip60_free_token_data(token_data_out);
+        return rc;
+    }
+
+    cJSON* del_item = cJSON_GetObjectItem(payload, "del");
+    if (del_item && cJSON_IsArray(del_item)) {
+        int del_count = cJSON_GetArraySize(del_item);
+        if (del_count > 0) {
+            token_data_out->deleted_token_ids = (char**)calloc((size_t)del_count, sizeof(char*));
+            if (!token_data_out->deleted_token_ids) {
+                cJSON_Delete(payload);
+                nostr_nip60_free_token_data(token_data_out);
+                return NOSTR_ERROR_MEMORY_FAILED;
+            }
+
+            for (int i = 0; i < del_count; i++) {
+                cJSON* it = cJSON_GetArrayItem(del_item, i);
+                if (!it || !cJSON_IsString(it)) continue;
+                const char* s = cJSON_GetStringValue(it);
+                if (!s) continue;
+                token_data_out->deleted_token_ids[token_data_out->deleted_count] = nip60_strdup(s);
+                if (!token_data_out->deleted_token_ids[token_data_out->deleted_count]) {
+                    cJSON_Delete(payload);
+                    nostr_nip60_free_token_data(token_data_out);
+                    return NOSTR_ERROR_MEMORY_FAILED;
+                }
+                token_data_out->deleted_count++;
+            }
+        }
+    }
+
+    cJSON_Delete(payload);
+    return NOSTR_SUCCESS;
+}
+
+void nostr_nip60_free_token_data(nostr_nip60_token_data_t* data) {
+    if (!data) return;
+
+    free(data->mint_url);
+    nostr_nip60_free_proofs(data->proofs, data->proof_count);
+
+    if (data->deleted_token_ids) {
+        for (int i = 0; i < data->deleted_count; i++) {
+            free(data->deleted_token_ids[i]);
+        }
+        free(data->deleted_token_ids);
+    }
+
+    memset(data, 0, sizeof(*data));
+}
+
+cJSON* nostr_nip60_create_token_deletion_with_signer(const char* token_event_id,
+                                                     nostr_signer_t* signer,
+                                                     time_t timestamp) {
+    if (!token_event_id || !signer) return NULL;
+
+    cJSON* tags = cJSON_CreateArray();
+    if (!tags) return NULL;
+
+    cJSON* e_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(e_tag, cJSON_CreateString("e"));
+    cJSON_AddItemToArray(e_tag, cJSON_CreateString(token_event_id));
+    cJSON_AddItemToArray(tags, e_tag);
+
+    cJSON* k_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(k_tag, cJSON_CreateString("k"));
+    cJSON_AddItemToArray(k_tag, cJSON_CreateString("7375"));
+    cJSON_AddItemToArray(tags, k_tag);
+
+    cJSON* evt = nostr_create_and_sign_event_with_signer(5, "NIP-60 token spent", tags, signer, timestamp);
+    cJSON_Delete(tags);
+    return evt;
+}
+
+cJSON* nostr_nip60_create_token_deletion(const char* token_event_id,
+                                         const unsigned char* private_key,
+                                         time_t timestamp) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (!private_key) return NULL;
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) return NULL;
+
+    evt = nostr_nip60_create_token_deletion_with_signer(token_event_id, signer, timestamp);
+    nostr_signer_free(signer);
+    return evt;
+}
+
+cJSON* nostr_nip60_create_rollover_token_with_signer(const nostr_nip60_token_data_t* remaining_proofs,
+                                                     const char** deleted_event_ids,
+                                                     int deleted_count,
+                                                     nostr_signer_t* signer,
+                                                     time_t timestamp) {
+    if (!remaining_proofs || !signer) return NULL;
+
+    nostr_nip60_token_data_t token = *remaining_proofs;
+    token.deleted_token_ids = (char**)deleted_event_ids;
+    token.deleted_count = deleted_count;
+
+    return nostr_nip60_create_token_event_with_signer(&token, signer, timestamp);
+}
+
+cJSON* nostr_nip60_create_rollover_token(const nostr_nip60_token_data_t* remaining_proofs,
+                                         const char** deleted_event_ids,
+                                         int deleted_count,
+                                         const unsigned char* private_key,
+                                         time_t timestamp) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (!private_key) return NULL;
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) return NULL;
+
+    evt = nostr_nip60_create_rollover_token_with_signer(remaining_proofs, deleted_event_ids, deleted_count,
+                                                         signer, timestamp);
+    nostr_signer_free(signer);
+    return evt;
+}
+
+cJSON* nostr_nip60_create_history_event_with_signer(const nostr_nip60_history_data_t* history_data,
+                                                    nostr_signer_t* signer,
+                                                    time_t timestamp) {
+    if (!history_data || !signer) return NULL;
+
+    cJSON* payload = cJSON_CreateArray();
+    if (!payload) return NULL;
+
+    cJSON* dir = cJSON_CreateArray();
+    cJSON_AddItemToArray(dir, cJSON_CreateString("direction"));
+    cJSON_AddItemToArray(dir, cJSON_CreateString(nip60_direction_to_string(history_data->direction)));
+    cJSON_AddItemToArray(payload, dir);
+
+    char amount_buf[32];
+    snprintf(amount_buf, sizeof(amount_buf), "%llu", (unsigned long long)history_data->amount);
+    cJSON* amt = cJSON_CreateArray();
+    cJSON_AddItemToArray(amt, cJSON_CreateString("amount"));
+    cJSON_AddItemToArray(amt, cJSON_CreateString(amount_buf));
+    cJSON_AddItemToArray(payload, amt);
+
+    for (int i = 0; i < history_data->ref_count; i++) {
+        cJSON* e = cJSON_CreateArray();
+        cJSON_AddItemToArray(e, cJSON_CreateString("e"));
+        cJSON_AddItemToArray(e, cJSON_CreateString(history_data->refs[i].event_id));
+        cJSON_AddItemToArray(e, cJSON_CreateString(history_data->refs[i].relay_hint));
+        cJSON_AddItemToArray(e, cJSON_CreateString(nip60_marker_to_string(history_data->refs[i].marker)));
+        cJSON_AddItemToArray(payload, e);
+    }
+
+    char* plain = cJSON_PrintUnformatted(payload);
+    cJSON_Delete(payload);
+    if (!plain) return NULL;
+
+    char encrypted[65536];
+    int rc = nip60_encrypt_self_with_signer(signer, plain, encrypted, sizeof(encrypted));
+    free(plain);
+    if (rc != NOSTR_SUCCESS) return NULL;
+
+    cJSON* tags = cJSON_CreateArray();
+    if (!tags) return NULL;
+
+    for (int i = 0; i < history_data->ref_count; i++) {
+        if (history_data->refs[i].marker != NOSTR_NIP60_REF_REDEEMED) continue;
+
+        cJSON* e = cJSON_CreateArray();
+        cJSON_AddItemToArray(e, cJSON_CreateString("e"));
+        cJSON_AddItemToArray(e, cJSON_CreateString(history_data->refs[i].event_id));
+        cJSON_AddItemToArray(e, cJSON_CreateString(history_data->refs[i].relay_hint));
+        cJSON_AddItemToArray(e, cJSON_CreateString("redeemed"));
+        cJSON_AddItemToArray(tags, e);
+    }
+
+    cJSON* evt = nostr_create_and_sign_event_with_signer(NOSTR_NIP60_HISTORY_KIND, encrypted, tags, signer, timestamp);
+    cJSON_Delete(tags);
+    return evt;
+}
+
+cJSON* nostr_nip60_create_history_event(const nostr_nip60_history_data_t* history_data,
+                                        const unsigned char* private_key,
+                                        time_t timestamp) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (!private_key) return NULL;
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) return NULL;
+
+    evt = nostr_nip60_create_history_event_with_signer(history_data, signer, timestamp);
+    nostr_signer_free(signer);
+    return evt;
+}
+
+int nostr_nip60_parse_history_event(cJSON* event,
+                                    const unsigned char* private_key,
+                                    nostr_nip60_history_data_t* history_data_out) {
+    if (!event || !private_key || !history_data_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    memset(history_data_out, 0, sizeof(*history_data_out));
+
+    cJSON* kind_item = cJSON_GetObjectItem(event, "kind");
+    if (!kind_item || !cJSON_IsNumber(kind_item) || (int)cJSON_GetNumberValue(kind_item) != NOSTR_NIP60_HISTORY_KIND) {
+        return NOSTR_ERROR_NIP60_INVALID_HISTORY;
+    }
+
+    char decrypted[65536];
+    int rc = nip60_decrypt_event_content(event, private_key, decrypted, sizeof(decrypted));
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    cJSON* payload = cJSON_Parse(decrypted);
+    if (!payload || !cJSON_IsArray(payload)) {
+        cJSON_Delete(payload);
+        return NOSTR_ERROR_NIP60_INVALID_HISTORY;
+    }
+
+    int ref_count = 0;
+    cJSON* row = NULL;
+    cJSON_ArrayForEach(row, payload) {
+        if (!cJSON_IsArray(row) || cJSON_GetArraySize(row) < 2) continue;
+        cJSON* k = cJSON_GetArrayItem(row, 0);
+        if (!k || !cJSON_IsString(k)) continue;
+        const char* key = cJSON_GetStringValue(k);
+        if (key && strcmp(key, "e") == 0) ref_count++;
+    }
+
+    if (ref_count > 0) {
+        history_data_out->refs = (nostr_nip60_history_ref_t*)calloc((size_t)ref_count, sizeof(nostr_nip60_history_ref_t));
+        if (!history_data_out->refs) {
+            cJSON_Delete(payload);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+    }
+
+    int ref_idx = 0;
+    cJSON_ArrayForEach(row, payload) {
+        if (!cJSON_IsArray(row) || cJSON_GetArraySize(row) < 2) continue;
+
+        cJSON* k = cJSON_GetArrayItem(row, 0);
+        cJSON* v = cJSON_GetArrayItem(row, 1);
+        if (!k || !v || !cJSON_IsString(k) || !cJSON_IsString(v)) continue;
+
+        const char* key = cJSON_GetStringValue(k);
+        const char* val = cJSON_GetStringValue(v);
+        if (!key || !val) continue;
+
+        if (strcmp(key, "direction") == 0) {
+            history_data_out->direction = nip60_string_to_direction(val);
+        } else if (strcmp(key, "amount") == 0) {
+            history_data_out->amount = (uint64_t)strtoull(val, NULL, 10);
+        } else if (strcmp(key, "e") == 0 && ref_idx < ref_count) {
+            strncpy(history_data_out->refs[ref_idx].event_id, val,
+                    sizeof(history_data_out->refs[ref_idx].event_id) - 1);
+
+            cJSON* relay_item = cJSON_GetArrayItem(row, 2);
+            cJSON* marker_item = cJSON_GetArrayItem(row, 3);
+
+            if (relay_item && cJSON_IsString(relay_item)) {
+                const char* relay = cJSON_GetStringValue(relay_item);
+                if (relay) {
+                    strncpy(history_data_out->refs[ref_idx].relay_hint, relay,
+                            sizeof(history_data_out->refs[ref_idx].relay_hint) - 1);
+                }
+            }
+
+            if (marker_item && cJSON_IsString(marker_item)) {
+                const char* m = cJSON_GetStringValue(marker_item);
+                history_data_out->refs[ref_idx].marker = nip60_string_to_marker(m);
+            } else {
+                history_data_out->refs[ref_idx].marker = NOSTR_NIP60_REF_CREATED;
+            }
+
+            ref_idx++;
+        }
+    }
+
+    history_data_out->ref_count = ref_idx;
+    cJSON_Delete(payload);
+    return NOSTR_SUCCESS;
+}
+
+void nostr_nip60_free_history_data(nostr_nip60_history_data_t* data) {
+    if (!data) return;
+    free(data->refs);
+    memset(data, 0, sizeof(*data));
+}
+
+cJSON* nostr_nip60_create_quote_event_with_signer(const char* quote_id,
+                                                  const char* mint_url,
+                                                  time_t expiration,
+                                                  nostr_signer_t* signer,
+                                                  time_t timestamp) {
+    if (!quote_id || !mint_url || !signer || expiration <= 0) {
+        return NULL;
+    }
+
+    char encrypted[4096];
+    int rc = nip60_encrypt_self_with_signer(signer, quote_id, encrypted, sizeof(encrypted));
+    if (rc != NOSTR_SUCCESS) return NULL;
+
+    cJSON* tags = cJSON_CreateArray();
+    if (!tags) return NULL;
+
+    cJSON* exp_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(exp_tag, cJSON_CreateString("expiration"));
+
+    char exp_buf[32];
+    snprintf(exp_buf, sizeof(exp_buf), "%lld", (long long)expiration);
+    cJSON_AddItemToArray(exp_tag, cJSON_CreateString(exp_buf));
+    cJSON_AddItemToArray(tags, exp_tag);
+
+    cJSON* mint_tag = cJSON_CreateArray();
+    cJSON_AddItemToArray(mint_tag, cJSON_CreateString("mint"));
+    cJSON_AddItemToArray(mint_tag, cJSON_CreateString(mint_url));
+    cJSON_AddItemToArray(tags, mint_tag);
+
+    cJSON* evt = nostr_create_and_sign_event_with_signer(NOSTR_NIP60_QUOTE_KIND, encrypted, tags, signer, timestamp);
+    cJSON_Delete(tags);
+    return evt;
+}
+
+cJSON* nostr_nip60_create_quote_event(const char* quote_id,
+                                      const char* mint_url,
+                                      time_t expiration,
+                                      const unsigned char* private_key,
+                                      time_t timestamp) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (!private_key) return NULL;
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) return NULL;
+
+    evt = nostr_nip60_create_quote_event_with_signer(quote_id, mint_url, expiration, signer, timestamp);
+    nostr_signer_free(signer);
+    return evt;
+}
+
+int nostr_nip60_parse_quote_event(cJSON* event,
+                                  const unsigned char* private_key,
+                                  char* quote_id_out,
+                                  size_t quote_id_size,
+                                  char* mint_url_out,
+                                  size_t mint_url_size,
+                                  time_t* expiration_out) {
+    if (!event || !private_key || !quote_id_out || quote_id_size == 0 ||
+        !mint_url_out || mint_url_size == 0) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    cJSON* kind_item = cJSON_GetObjectItem(event, "kind");
+    if (!kind_item || !cJSON_IsNumber(kind_item) || (int)cJSON_GetNumberValue(kind_item) != NOSTR_NIP60_QUOTE_KIND) {
+        return NOSTR_ERROR_NIP60_INVALID_QUOTE;
+    }
+
+    char decrypted[4096];
+    int rc = nip60_decrypt_event_content(event, private_key, decrypted, sizeof(decrypted));
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    strncpy(quote_id_out, decrypted, quote_id_size - 1);
+    quote_id_out[quote_id_size - 1] = '\0';
+
+    mint_url_out[0] = '\0';
+    if (expiration_out) *expiration_out = 0;
+
+    cJSON* tags = cJSON_GetObjectItem(event, "tags");
+    if (tags && cJSON_IsArray(tags)) {
+        cJSON* tag = NULL;
+        cJSON_ArrayForEach(tag, tags) {
+            if (!cJSON_IsArray(tag) || cJSON_GetArraySize(tag) < 2) continue;
+            cJSON* k = cJSON_GetArrayItem(tag, 0);
+            cJSON* v = cJSON_GetArrayItem(tag, 1);
+            if (!k || !v || !cJSON_IsString(k) || !cJSON_IsString(v)) continue;
+
+            const char* key = cJSON_GetStringValue(k);
+            const char* val = cJSON_GetStringValue(v);
+            if (!key || !val) continue;
+
+            if (strcmp(key, "mint") == 0) {
+                strncpy(mint_url_out, val, mint_url_size - 1);
+                mint_url_out[mint_url_size - 1] = '\0';
+            } else if (strcmp(key, "expiration") == 0 && expiration_out) {
+                *expiration_out = (time_t)strtoll(val, NULL, 10);
+            }
+        }
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+cJSON* nostr_nip60_create_wallet_filter(const char* pubkey_hex) {
+    if (!pubkey_hex) return NULL;
+
+    cJSON* filter = cJSON_CreateObject();
+    if (!filter) return NULL;
+
+    cJSON* kinds = cJSON_CreateArray();
+    cJSON_AddItemToArray(kinds, cJSON_CreateNumber(NOSTR_NIP60_WALLET_KIND));
+    cJSON_AddItemToArray(kinds, cJSON_CreateNumber(NOSTR_NIP60_TOKEN_KIND));
+    cJSON_AddItemToObject(filter, "kinds", kinds);
+
+    cJSON* authors = cJSON_CreateArray();
+    cJSON_AddItemToArray(authors, cJSON_CreateString(pubkey_hex));
+    cJSON_AddItemToObject(filter, "authors", authors);
+
+    return filter;
+}
+
+cJSON* nostr_nip60_create_history_filter(const char* pubkey_hex, time_t since) {
+    if (!pubkey_hex) return NULL;
+
+    cJSON* filter = cJSON_CreateObject();
+    if (!filter) return NULL;
+
+    cJSON* kinds = cJSON_CreateArray();
+    cJSON_AddItemToArray(kinds, cJSON_CreateNumber(NOSTR_NIP60_HISTORY_KIND));
+    cJSON_AddItemToObject(filter, "kinds", kinds);
+
+    cJSON* authors = cJSON_CreateArray();
+    cJSON_AddItemToArray(authors, cJSON_CreateString(pubkey_hex));
+    cJSON_AddItemToObject(filter, "authors", authors);
+
+    if (since > 0) {
+        cJSON_AddNumberToObject(filter, "since", (double)since);
+    }
+
+    return filter;
+}

nostr_core/nip060.h

@@ -0,0 +1,169 @@
+/*
+ * NIP-60: Cashu Wallet
+ * https://github.com/nostr-protocol/nips/blob/master/60.md
+ */
+
+#ifndef NOSTR_NIP060_H
+#define NOSTR_NIP060_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <time.h>
+#include "nip001.h"
+#include "nostr_common.h"
+#include "nostr_signer.h"
+#include "../cjson/cJSON.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define NOSTR_NIP60_WALLET_KIND 17375
+#define NOSTR_NIP60_TOKEN_KIND 7375
+#define NOSTR_NIP60_HISTORY_KIND 7376
+#define NOSTR_NIP60_QUOTE_KIND 7374
+
+#define NOSTR_CASHU_KEYSET_ID_HEX_SIZE 65
+#define NOSTR_CASHU_PUBKEY_HEX_SIZE 67
+#define NOSTR_CASHU_EVENT_ID_HEX_SIZE 65
+
+typedef struct {
+    char id[NOSTR_CASHU_KEYSET_ID_HEX_SIZE];
+    uint64_t amount;
+    char* secret;
+    char* C;
+} nostr_cashu_proof_t;
+
+typedef struct {
+    char privkey[65];
+    char** mint_urls;
+    int mint_count;
+} nostr_nip60_wallet_data_t;
+
+typedef struct {
+    char* mint_url;
+    nostr_cashu_proof_t* proofs;
+    int proof_count;
+    char** deleted_token_ids;
+    int deleted_count;
+} nostr_nip60_token_data_t;
+
+typedef enum {
+    NOSTR_NIP60_DIRECTION_IN = 0,
+    NOSTR_NIP60_DIRECTION_OUT = 1
+} nostr_nip60_direction_t;
+
+typedef enum {
+    NOSTR_NIP60_REF_CREATED = 0,
+    NOSTR_NIP60_REF_DESTROYED = 1,
+    NOSTR_NIP60_REF_REDEEMED = 2
+} nostr_nip60_ref_marker_t;
+
+typedef struct {
+    char event_id[NOSTR_CASHU_EVENT_ID_HEX_SIZE];
+    char relay_hint[256];
+    nostr_nip60_ref_marker_t marker;
+} nostr_nip60_history_ref_t;
+
+typedef struct {
+    nostr_nip60_direction_t direction;
+    uint64_t amount;
+    nostr_nip60_history_ref_t* refs;
+    int ref_count;
+} nostr_nip60_history_data_t;
+
+cJSON* nostr_nip60_create_wallet_event(const nostr_nip60_wallet_data_t* wallet_data,
+                                       const unsigned char* private_key,
+                                       time_t timestamp);
+cJSON* nostr_nip60_create_wallet_event_with_signer(const nostr_nip60_wallet_data_t* wallet_data,
+                                                   nostr_signer_t* signer,
+                                                   time_t timestamp);
+
+int nostr_nip60_parse_wallet_event(cJSON* event,
+                                   const unsigned char* private_key,
+                                   nostr_nip60_wallet_data_t* wallet_data_out);
+
+void nostr_nip60_free_wallet_data(nostr_nip60_wallet_data_t* data);
+
+cJSON* nostr_nip60_create_token_event(const nostr_nip60_token_data_t* token_data,
+                                      const unsigned char* private_key,
+                                      time_t timestamp);
+cJSON* nostr_nip60_create_token_event_with_signer(const nostr_nip60_token_data_t* token_data,
+                                                  nostr_signer_t* signer,
+                                                  time_t timestamp);
+
+int nostr_nip60_parse_token_event(cJSON* event,
+                                  const unsigned char* private_key,
+                                  nostr_nip60_token_data_t* token_data_out);
+
+void nostr_nip60_free_token_data(nostr_nip60_token_data_t* data);
+
+cJSON* nostr_nip60_create_token_deletion(const char* token_event_id,
+                                         const unsigned char* private_key,
+                                         time_t timestamp);
+cJSON* nostr_nip60_create_token_deletion_with_signer(const char* token_event_id,
+                                                     nostr_signer_t* signer,
+                                                     time_t timestamp);
+
+cJSON* nostr_nip60_create_rollover_token(const nostr_nip60_token_data_t* remaining_proofs,
+                                         const char** deleted_event_ids,
+                                         int deleted_count,
+                                         const unsigned char* private_key,
+                                         time_t timestamp);
+cJSON* nostr_nip60_create_rollover_token_with_signer(const nostr_nip60_token_data_t* remaining_proofs,
+                                                     const char** deleted_event_ids,
+                                                     int deleted_count,
+                                                     nostr_signer_t* signer,
+                                                     time_t timestamp);
+
+cJSON* nostr_nip60_create_history_event(const nostr_nip60_history_data_t* history_data,
+                                        const unsigned char* private_key,
+                                        time_t timestamp);
+cJSON* nostr_nip60_create_history_event_with_signer(const nostr_nip60_history_data_t* history_data,
+                                                    nostr_signer_t* signer,
+                                                    time_t timestamp);
+
+int nostr_nip60_parse_history_event(cJSON* event,
+                                    const unsigned char* private_key,
+                                    nostr_nip60_history_data_t* history_data_out);
+
+void nostr_nip60_free_history_data(nostr_nip60_history_data_t* data);
+
+cJSON* nostr_nip60_create_quote_event(const char* quote_id,
+                                      const char* mint_url,
+                                      time_t expiration,
+                                      const unsigned char* private_key,
+                                      time_t timestamp);
+cJSON* nostr_nip60_create_quote_event_with_signer(const char* quote_id,
+                                                  const char* mint_url,
+                                                  time_t expiration,
+                                                  nostr_signer_t* signer,
+                                                  time_t timestamp);
+
+int nostr_nip60_parse_quote_event(cJSON* event,
+                                  const unsigned char* private_key,
+                                  char* quote_id_out,
+                                  size_t quote_id_size,
+                                  char* mint_url_out,
+                                  size_t mint_url_size,
+                                  time_t* expiration_out);
+
+uint64_t nostr_nip60_sum_proofs(const nostr_cashu_proof_t* proofs, int proof_count);
+
+cJSON* nostr_nip60_proofs_to_json(const nostr_cashu_proof_t* proofs, int proof_count);
+
+int nostr_nip60_proofs_from_json(cJSON* json_array,
+                                 nostr_cashu_proof_t** proofs_out,
+                                 int* proof_count_out);
+
+void nostr_nip60_free_proofs(nostr_cashu_proof_t* proofs, int proof_count);
+
+cJSON* nostr_nip60_create_wallet_filter(const char* pubkey_hex);
+
+cJSON* nostr_nip60_create_history_filter(const char* pubkey_hex, time_t since);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_NIP060_H */

nostr_core/nip061.c

@@ -0,0 +1,604 @@
+/*
+ * NIP-61: Nutzaps Implementation
+ * https://github.com/nostr-protocol/nips/blob/master/61.md
+ */
+
+#include "nip061.h"
+#include "nip060.h"
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+static char* nip61_strdup(const char* s) {
+    if (!s) return NULL;
+    size_t len = strlen(s);
+    char* out = (char*)malloc(len + 1);
+    if (!out) return NULL;
+    memcpy(out, s, len + 1);
+    return out;
+}
+
+static int nip61_mint_in_info(const char* mint_url, const nostr_nip61_nutzap_info_t* info) {
+    if (!mint_url || !info) return 0;
+    for (int i = 0; i < info->mint_count; i++) {
+        if (info->mints[i].url && strcmp(info->mints[i].url, mint_url) == 0) {
+            return 1;
+        }
+    }
+    return 0;
+}
+
+cJSON* nostr_nip61_create_nutzap_info_event_with_signer(const nostr_nip61_nutzap_info_t* info,
+                                                        nostr_signer_t* signer,
+                                                        time_t timestamp) {
+    if (!info || !signer || info->mint_count <= 0 || info->relay_count <= 0 || info->pubkey[0] == '\0') {
+        return NULL;
+    }
+
+    cJSON* tags = cJSON_CreateArray();
+    if (!tags) return NULL;
+
+    for (int i = 0; i < info->relay_count; i++) {
+        if (!info->relay_urls || !info->relay_urls[i]) continue;
+        cJSON* relay = cJSON_CreateArray();
+        cJSON_AddItemToArray(relay, cJSON_CreateString("relay"));
+        cJSON_AddItemToArray(relay, cJSON_CreateString(info->relay_urls[i]));
+        cJSON_AddItemToArray(tags, relay);
+    }
+
+    for (int i = 0; i < info->mint_count; i++) {
+        if (!info->mints || !info->mints[i].url) continue;
+        cJSON* mint = cJSON_CreateArray();
+        cJSON_AddItemToArray(mint, cJSON_CreateString("mint"));
+        cJSON_AddItemToArray(mint, cJSON_CreateString(info->mints[i].url));
+        for (int u = 0; u < info->mints[i].unit_count; u++) {
+            if (info->mints[i].units && info->mints[i].units[u]) {
+                cJSON_AddItemToArray(mint, cJSON_CreateString(info->mints[i].units[u]));
+            }
+        }
+        cJSON_AddItemToArray(tags, mint);
+    }
+
+    cJSON* pub = cJSON_CreateArray();
+    cJSON_AddItemToArray(pub, cJSON_CreateString("pubkey"));
+    cJSON_AddItemToArray(pub, cJSON_CreateString(info->pubkey));
+    cJSON_AddItemToArray(tags, pub);
+
+    cJSON* evt = nostr_create_and_sign_event_with_signer(NOSTR_NIP61_NUTZAP_INFO_KIND, "", tags, signer, timestamp);
+    cJSON_Delete(tags);
+    return evt;
+}
+
+cJSON* nostr_nip61_create_nutzap_info_event(const nostr_nip61_nutzap_info_t* info,
+                                            const unsigned char* private_key,
+                                            time_t timestamp) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (!private_key) return NULL;
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) return NULL;
+
+    evt = nostr_nip61_create_nutzap_info_event_with_signer(info, signer, timestamp);
+    nostr_signer_free(signer);
+    return evt;
+}
+
+int nostr_nip61_parse_nutzap_info_event(cJSON* event,
+                                        nostr_nip61_nutzap_info_t* info_out) {
+    if (!event || !info_out) return NOSTR_ERROR_INVALID_INPUT;
+
+    memset(info_out, 0, sizeof(*info_out));
+
+    cJSON* kind_item = cJSON_GetObjectItem(event, "kind");
+    cJSON* tags = cJSON_GetObjectItem(event, "tags");
+    if (!kind_item || !cJSON_IsNumber(kind_item) || (int)cJSON_GetNumberValue(kind_item) != NOSTR_NIP61_NUTZAP_INFO_KIND ||
+        !tags || !cJSON_IsArray(tags)) {
+        return NOSTR_ERROR_NIP61_INVALID_INFO;
+    }
+
+    int relay_count = 0;
+    int mint_count = 0;
+
+    cJSON* tag = NULL;
+    cJSON_ArrayForEach(tag, tags) {
+        if (!cJSON_IsArray(tag) || cJSON_GetArraySize(tag) < 2) continue;
+        cJSON* t0 = cJSON_GetArrayItem(tag, 0);
+        if (!t0 || !cJSON_IsString(t0)) continue;
+        const char* key = cJSON_GetStringValue(t0);
+        if (!key) continue;
+        if (strcmp(key, "relay") == 0) relay_count++;
+        if (strcmp(key, "mint") == 0) mint_count++;
+    }
+
+    if (relay_count > 0) {
+        info_out->relay_urls = (char**)calloc((size_t)relay_count, sizeof(char*));
+        if (!info_out->relay_urls) return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    if (mint_count > 0) {
+        info_out->mints = (nostr_nip61_mint_entry_t*)calloc((size_t)mint_count, sizeof(nostr_nip61_mint_entry_t));
+        if (!info_out->mints) {
+            nostr_nip61_free_nutzap_info(info_out);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+    }
+
+    int relay_idx = 0;
+    int mint_idx = 0;
+
+    cJSON_ArrayForEach(tag, tags) {
+        if (!cJSON_IsArray(tag) || cJSON_GetArraySize(tag) < 2) continue;
+        cJSON* t0 = cJSON_GetArrayItem(tag, 0);
+        cJSON* t1 = cJSON_GetArrayItem(tag, 1);
+        if (!t0 || !t1 || !cJSON_IsString(t0) || !cJSON_IsString(t1)) continue;
+
+        const char* key = cJSON_GetStringValue(t0);
+        const char* val = cJSON_GetStringValue(t1);
+        if (!key || !val) continue;
+
+        if (strcmp(key, "relay") == 0 && relay_idx < relay_count) {
+            info_out->relay_urls[relay_idx] = nip61_strdup(val);
+            if (!info_out->relay_urls[relay_idx]) {
+                nostr_nip61_free_nutzap_info(info_out);
+                return NOSTR_ERROR_MEMORY_FAILED;
+            }
+            relay_idx++;
+        } else if (strcmp(key, "mint") == 0 && mint_idx < mint_count) {
+            info_out->mints[mint_idx].url = nip61_strdup(val);
+            if (!info_out->mints[mint_idx].url) {
+                nostr_nip61_free_nutzap_info(info_out);
+                return NOSTR_ERROR_MEMORY_FAILED;
+            }
+
+            int total = cJSON_GetArraySize(tag);
+            int unit_count = (total > 2) ? (total - 2) : 0;
+            if (unit_count > 0) {
+                info_out->mints[mint_idx].units = (char**)calloc((size_t)unit_count, sizeof(char*));
+                if (!info_out->mints[mint_idx].units) {
+                    nostr_nip61_free_nutzap_info(info_out);
+                    return NOSTR_ERROR_MEMORY_FAILED;
+                }
+
+                for (int u = 0; u < unit_count; u++) {
+                    cJSON* unit_item = cJSON_GetArrayItem(tag, u + 2);
+                    if (unit_item && cJSON_IsString(unit_item)) {
+                        const char* us = cJSON_GetStringValue(unit_item);
+                        if (us) {
+                            info_out->mints[mint_idx].units[info_out->mints[mint_idx].unit_count] = nip61_strdup(us);
+                            if (!info_out->mints[mint_idx].units[info_out->mints[mint_idx].unit_count]) {
+                                nostr_nip61_free_nutzap_info(info_out);
+                                return NOSTR_ERROR_MEMORY_FAILED;
+                            }
+                            info_out->mints[mint_idx].unit_count++;
+                        }
+                    }
+                }
+            }
+            mint_idx++;
+        } else if (strcmp(key, "pubkey") == 0) {
+            strncpy(info_out->pubkey, val, sizeof(info_out->pubkey) - 1);
+            info_out->pubkey[sizeof(info_out->pubkey) - 1] = '\0';
+        }
+    }
+
+    info_out->relay_count = relay_idx;
+    info_out->mint_count = mint_idx;
+
+    if (info_out->pubkey[0] == '\0' || info_out->mint_count == 0) {
+        nostr_nip61_free_nutzap_info(info_out);
+        return NOSTR_ERROR_NIP61_INVALID_INFO;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+void nostr_nip61_free_nutzap_info(nostr_nip61_nutzap_info_t* info) {
+    if (!info) return;
+
+    if (info->relay_urls) {
+        for (int i = 0; i < info->relay_count; i++) {
+            free(info->relay_urls[i]);
+        }
+        free(info->relay_urls);
+    }
+
+    if (info->mints) {
+        for (int i = 0; i < info->mint_count; i++) {
+            free(info->mints[i].url);
+            if (info->mints[i].units) {
+                for (int u = 0; u < info->mints[i].unit_count; u++) {
+                    free(info->mints[i].units[u]);
+                }
+                free(info->mints[i].units);
+            }
+        }
+        free(info->mints);
+    }
+
+    memset(info, 0, sizeof(*info));
+}
+
+cJSON* nostr_nip61_create_nutzap_event_with_signer(const nostr_nip61_nutzap_data_t* nutzap_data,
+                                                   nostr_signer_t* signer,
+                                                   time_t timestamp) {
+    if (!nutzap_data || !signer || !nutzap_data->mint_url ||
+        !nutzap_data->proofs || nutzap_data->proof_count <= 0 ||
+        nutzap_data->recipient_pubkey[0] == '\0') {
+        return NULL;
+    }
+
+    cJSON* tags = cJSON_CreateArray();
+    if (!tags) return NULL;
+
+    for (int i = 0; i < nutzap_data->proof_count; i++) {
+        cJSON* proof_json = cJSON_CreateObject();
+        cJSON_AddStringToObject(proof_json, "id", nutzap_data->proofs[i].id);
+        cJSON_AddNumberToObject(proof_json, "amount", (double)nutzap_data->proofs[i].amount);
+        cJSON_AddStringToObject(proof_json, "secret", nutzap_data->proofs[i].secret ? nutzap_data->proofs[i].secret : "");
+        cJSON_AddStringToObject(proof_json, "C", nutzap_data->proofs[i].C ? nutzap_data->proofs[i].C : "");
+
+        char* proof_str = cJSON_PrintUnformatted(proof_json);
+        cJSON_Delete(proof_json);
+        if (!proof_str) {
+            cJSON_Delete(tags);
+            return NULL;
+        }
+
+        cJSON* proof_tag = cJSON_CreateArray();
+        cJSON_AddItemToArray(proof_tag, cJSON_CreateString("proof"));
+        cJSON_AddItemToArray(proof_tag, cJSON_CreateString(proof_str));
+        cJSON_AddItemToArray(tags, proof_tag);
+        free(proof_str);
+    }
+
+    cJSON* u = cJSON_CreateArray();
+    cJSON_AddItemToArray(u, cJSON_CreateString("u"));
+    cJSON_AddItemToArray(u, cJSON_CreateString(nutzap_data->mint_url));
+    cJSON_AddItemToArray(tags, u);
+
+    cJSON* p = cJSON_CreateArray();
+    cJSON_AddItemToArray(p, cJSON_CreateString("p"));
+    cJSON_AddItemToArray(p, cJSON_CreateString(nutzap_data->recipient_pubkey));
+    cJSON_AddItemToArray(tags, p);
+
+    if (nutzap_data->nutzapped_event_id[0] != '\0') {
+        cJSON* e = cJSON_CreateArray();
+        cJSON_AddItemToArray(e, cJSON_CreateString("e"));
+        cJSON_AddItemToArray(e, cJSON_CreateString(nutzap_data->nutzapped_event_id));
+        cJSON_AddItemToArray(e, cJSON_CreateString(nutzap_data->nutzapped_relay_hint));
+        cJSON_AddItemToArray(tags, e);
+
+        if (nutzap_data->nutzapped_kind > 0) {
+            cJSON* k = cJSON_CreateArray();
+            char kind_buf[16];
+            snprintf(kind_buf, sizeof(kind_buf), "%d", nutzap_data->nutzapped_kind);
+            cJSON_AddItemToArray(k, cJSON_CreateString("k"));
+            cJSON_AddItemToArray(k, cJSON_CreateString(kind_buf));
+            cJSON_AddItemToArray(tags, k);
+        }
+    }
+
+    const char* content = nutzap_data->content ? nutzap_data->content : "";
+    cJSON* evt = nostr_create_and_sign_event_with_signer(NOSTR_NIP61_NUTZAP_KIND, content, tags, signer, timestamp);
+    cJSON_Delete(tags);
+    return evt;
+}
+
+cJSON* nostr_nip61_create_nutzap_event(const nostr_nip61_nutzap_data_t* nutzap_data,
+                                       const unsigned char* sender_private_key,
+                                       time_t timestamp) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (!sender_private_key) return NULL;
+
+    signer = nostr_signer_local(sender_private_key);
+    if (!signer) return NULL;
+
+    evt = nostr_nip61_create_nutzap_event_with_signer(nutzap_data, signer, timestamp);
+    nostr_signer_free(signer);
+    return evt;
+}
+
+int nostr_nip61_parse_nutzap_event(cJSON* event,
+                                   nostr_nip61_nutzap_data_t* nutzap_data_out) {
+    if (!event || !nutzap_data_out) return NOSTR_ERROR_INVALID_INPUT;
+
+    memset(nutzap_data_out, 0, sizeof(*nutzap_data_out));
+
+    cJSON* kind_item = cJSON_GetObjectItem(event, "kind");
+    cJSON* tags = cJSON_GetObjectItem(event, "tags");
+    cJSON* content = cJSON_GetObjectItem(event, "content");
+
+    if (!kind_item || !cJSON_IsNumber(kind_item) || (int)cJSON_GetNumberValue(kind_item) != NOSTR_NIP61_NUTZAP_KIND ||
+        !tags || !cJSON_IsArray(tags) || !content || !cJSON_IsString(content)) {
+        return NOSTR_ERROR_NIP61_INVALID_NUTZAP;
+    }
+
+    const char* content_str = cJSON_GetStringValue(content);
+    nutzap_data_out->content = nip61_strdup(content_str ? content_str : "");
+    if (!nutzap_data_out->content) return NOSTR_ERROR_MEMORY_FAILED;
+
+    int proof_count = 0;
+    cJSON* tag = NULL;
+    cJSON_ArrayForEach(tag, tags) {
+        if (!cJSON_IsArray(tag) || cJSON_GetArraySize(tag) < 2) continue;
+        cJSON* t0 = cJSON_GetArrayItem(tag, 0);
+        if (t0 && cJSON_IsString(t0) && strcmp(cJSON_GetStringValue(t0), "proof") == 0) {
+            proof_count++;
+        }
+    }
+
+    if (proof_count > 0) {
+        nutzap_data_out->proofs = (nostr_cashu_proof_t*)calloc((size_t)proof_count, sizeof(nostr_cashu_proof_t));
+        if (!nutzap_data_out->proofs) {
+            nostr_nip61_free_nutzap_data(nutzap_data_out);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+    }
+
+    int proof_idx = 0;
+    cJSON_ArrayForEach(tag, tags) {
+        if (!cJSON_IsArray(tag) || cJSON_GetArraySize(tag) < 2) continue;
+        cJSON* t0 = cJSON_GetArrayItem(tag, 0);
+        cJSON* t1 = cJSON_GetArrayItem(tag, 1);
+        if (!t0 || !t1 || !cJSON_IsString(t0) || !cJSON_IsString(t1)) continue;
+
+        const char* key = cJSON_GetStringValue(t0);
+        const char* val = cJSON_GetStringValue(t1);
+        if (!key || !val) continue;
+
+        if (strcmp(key, "proof") == 0 && proof_idx < proof_count) {
+            cJSON* proof_obj = cJSON_Parse(val);
+            if (!proof_obj || !cJSON_IsObject(proof_obj)) {
+                cJSON_Delete(proof_obj);
+                continue;
+            }
+
+            cJSON* id = cJSON_GetObjectItem(proof_obj, "id");
+            cJSON* amount = cJSON_GetObjectItem(proof_obj, "amount");
+            cJSON* secret = cJSON_GetObjectItem(proof_obj, "secret");
+            cJSON* C = cJSON_GetObjectItem(proof_obj, "C");
+
+            if (id && cJSON_IsString(id) && amount && cJSON_IsNumber(amount) &&
+                secret && cJSON_IsString(secret) && C && cJSON_IsString(C)) {
+                const char* id_s = cJSON_GetStringValue(id);
+                const char* sec_s = cJSON_GetStringValue(secret);
+                const char* c_s = cJSON_GetStringValue(C);
+
+                if (id_s && sec_s && c_s) {
+                    strncpy(nutzap_data_out->proofs[proof_idx].id, id_s,
+                            sizeof(nutzap_data_out->proofs[proof_idx].id) - 1);
+                    nutzap_data_out->proofs[proof_idx].amount = (uint64_t)cJSON_GetNumberValue(amount);
+                    nutzap_data_out->proofs[proof_idx].secret = nip61_strdup(sec_s);
+                    nutzap_data_out->proofs[proof_idx].C = nip61_strdup(c_s);
+                    if (!nutzap_data_out->proofs[proof_idx].secret || !nutzap_data_out->proofs[proof_idx].C) {
+                        cJSON_Delete(proof_obj);
+                        nostr_nip61_free_nutzap_data(nutzap_data_out);
+                        return NOSTR_ERROR_MEMORY_FAILED;
+                    }
+                    proof_idx++;
+                }
+            }
+
+            cJSON_Delete(proof_obj);
+        } else if (strcmp(key, "u") == 0) {
+            free(nutzap_data_out->mint_url);
+            nutzap_data_out->mint_url = nip61_strdup(val);
+            if (!nutzap_data_out->mint_url) {
+                nostr_nip61_free_nutzap_data(nutzap_data_out);
+                return NOSTR_ERROR_MEMORY_FAILED;
+            }
+        } else if (strcmp(key, "p") == 0) {
+            strncpy(nutzap_data_out->recipient_pubkey, val, sizeof(nutzap_data_out->recipient_pubkey) - 1);
+        } else if (strcmp(key, "e") == 0) {
+            strncpy(nutzap_data_out->nutzapped_event_id, val, sizeof(nutzap_data_out->nutzapped_event_id) - 1);
+            cJSON* t2 = cJSON_GetArrayItem(tag, 2);
+            if (t2 && cJSON_IsString(t2)) {
+                const char* relay = cJSON_GetStringValue(t2);
+                if (relay) strncpy(nutzap_data_out->nutzapped_relay_hint, relay,
+                                   sizeof(nutzap_data_out->nutzapped_relay_hint) - 1);
+            }
+        } else if (strcmp(key, "k") == 0) {
+            nutzap_data_out->nutzapped_kind = atoi(val);
+        }
+    }
+
+    nutzap_data_out->proof_count = proof_idx;
+
+    if (!nutzap_data_out->mint_url || nutzap_data_out->recipient_pubkey[0] == '\0' || proof_idx == 0) {
+        nostr_nip61_free_nutzap_data(nutzap_data_out);
+        return NOSTR_ERROR_NIP61_INVALID_NUTZAP;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+void nostr_nip61_free_nutzap_data(nostr_nip61_nutzap_data_t* data) {
+    if (!data) return;
+    free(data->content);
+    free(data->mint_url);
+    nostr_nip60_free_proofs(data->proofs, data->proof_count);
+    memset(data, 0, sizeof(*data));
+}
+
+cJSON* nostr_nip61_create_redemption_event_with_signer(const char* nutzap_event_id,
+                                                       const char* nutzap_relay_hint,
+                                                       const char* sender_pubkey,
+                                                       const char* created_token_event_id,
+                                                       const char* created_token_relay_hint,
+                                                       uint64_t amount,
+                                                       nostr_signer_t* signer,
+                                                       time_t timestamp) {
+    if (!nutzap_event_id || !sender_pubkey || !created_token_event_id || !signer) {
+        return NULL;
+    }
+
+    nostr_nip60_history_ref_t refs[1];
+    memset(refs, 0, sizeof(refs));
+    strncpy(refs[0].event_id, created_token_event_id, sizeof(refs[0].event_id) - 1);
+    if (created_token_relay_hint) {
+        strncpy(refs[0].relay_hint, created_token_relay_hint, sizeof(refs[0].relay_hint) - 1);
+    }
+    refs[0].marker = NOSTR_NIP60_REF_CREATED;
+
+    nostr_nip60_history_data_t hist;
+    memset(&hist, 0, sizeof(hist));
+    hist.direction = NOSTR_NIP60_DIRECTION_IN;
+    hist.amount = amount;
+    hist.refs = refs;
+    hist.ref_count = 1;
+
+    cJSON* evt = nostr_nip60_create_history_event_with_signer(&hist, signer, timestamp);
+    if (!evt) return NULL;
+
+    cJSON* tags = cJSON_GetObjectItem(evt, "tags");
+    if (!tags || !cJSON_IsArray(tags)) return evt;
+
+    cJSON* e = cJSON_CreateArray();
+    cJSON_AddItemToArray(e, cJSON_CreateString("e"));
+    cJSON_AddItemToArray(e, cJSON_CreateString(nutzap_event_id));
+    cJSON_AddItemToArray(e, cJSON_CreateString(nutzap_relay_hint ? nutzap_relay_hint : ""));
+    cJSON_AddItemToArray(e, cJSON_CreateString("redeemed"));
+    cJSON_AddItemToArray(tags, e);
+
+    cJSON* p = cJSON_CreateArray();
+    cJSON_AddItemToArray(p, cJSON_CreateString("p"));
+    cJSON_AddItemToArray(p, cJSON_CreateString(sender_pubkey));
+    cJSON_AddItemToArray(tags, p);
+
+    return evt;
+}
+
+cJSON* nostr_nip61_create_redemption_event(const char* nutzap_event_id,
+                                           const char* nutzap_relay_hint,
+                                           const char* sender_pubkey,
+                                           const char* created_token_event_id,
+                                           const char* created_token_relay_hint,
+                                           uint64_t amount,
+                                           const unsigned char* private_key,
+                                           time_t timestamp) {
+    nostr_signer_t* signer;
+    cJSON* evt;
+
+    if (!private_key) {
+        return NULL;
+    }
+
+    signer = nostr_signer_local(private_key);
+    if (!signer) {
+        return NULL;
+    }
+
+    evt = nostr_nip61_create_redemption_event_with_signer(nutzap_event_id,
+                                                           nutzap_relay_hint,
+                                                           sender_pubkey,
+                                                           created_token_event_id,
+                                                           created_token_relay_hint,
+                                                           amount,
+                                                           signer,
+                                                           timestamp);
+    nostr_signer_free(signer);
+    return evt;
+}
+
+int nostr_nip61_verify_nutzap(cJSON* nutzap_event, cJSON* nutzap_info_event) {
+    if (!nutzap_event || !nutzap_info_event) return NOSTR_ERROR_INVALID_INPUT;
+
+    nostr_nip61_nutzap_data_t nutzap;
+    memset(&nutzap, 0, sizeof(nutzap));
+    int rc = nostr_nip61_parse_nutzap_event(nutzap_event, &nutzap);
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    nostr_nip61_nutzap_info_t info;
+    memset(&info, 0, sizeof(info));
+    rc = nostr_nip61_parse_nutzap_info_event(nutzap_info_event, &info);
+    if (rc != NOSTR_SUCCESS) {
+        nostr_nip61_free_nutzap_data(&nutzap);
+        return rc;
+    }
+
+    if (!nip61_mint_in_info(nutzap.mint_url, &info)) {
+        nostr_nip61_free_nutzap_data(&nutzap);
+        nostr_nip61_free_nutzap_info(&info);
+        return NOSTR_ERROR_NIP61_MINT_MISMATCH;
+    }
+
+    int key_match = 0;
+    if (strlen(info.pubkey) == 64) {
+        for (int i = 0; i < nutzap.proof_count; i++) {
+            if (nutzap.proofs[i].secret && strstr(nutzap.proofs[i].secret, info.pubkey) != NULL) {
+                key_match = 1;
+                break;
+            }
+        }
+    } else if (strlen(info.pubkey) == 66 && strncmp(info.pubkey, "02", 2) == 0) {
+        const char* xonly = info.pubkey + 2;
+        for (int i = 0; i < nutzap.proof_count; i++) {
+            if (nutzap.proofs[i].secret && strstr(nutzap.proofs[i].secret, xonly) != NULL) {
+                key_match = 1;
+                break;
+            }
+        }
+    }
+
+    nostr_nip61_free_nutzap_data(&nutzap);
+    nostr_nip61_free_nutzap_info(&info);
+
+    if (!key_match) {
+        return NOSTR_ERROR_NIP61_PUBKEY_MISMATCH;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+cJSON* nostr_nip61_create_nutzap_info_filter(const char* pubkey_hex) {
+    if (!pubkey_hex) return NULL;
+
+    cJSON* filter = cJSON_CreateObject();
+    if (!filter) return NULL;
+
+    cJSON* kinds = cJSON_CreateArray();
+    cJSON_AddItemToArray(kinds, cJSON_CreateNumber(NOSTR_NIP61_NUTZAP_INFO_KIND));
+    cJSON_AddItemToObject(filter, "kinds", kinds);
+
+    cJSON* authors = cJSON_CreateArray();
+    cJSON_AddItemToArray(authors, cJSON_CreateString(pubkey_hex));
+    cJSON_AddItemToObject(filter, "authors", authors);
+
+    return filter;
+}
+
+cJSON* nostr_nip61_create_nutzap_filter(const char* recipient_pubkey_hex,
+                                        const char** mint_urls,
+                                        int mint_count,
+                                        time_t since) {
+    if (!recipient_pubkey_hex) return NULL;
+
+    cJSON* filter = cJSON_CreateObject();
+    if (!filter) return NULL;
+
+    cJSON* kinds = cJSON_CreateArray();
+    cJSON_AddItemToArray(kinds, cJSON_CreateNumber(NOSTR_NIP61_NUTZAP_KIND));
+    cJSON_AddItemToObject(filter, "kinds", kinds);
+
+    cJSON* pvals = cJSON_CreateArray();
+    cJSON_AddItemToArray(pvals, cJSON_CreateString(recipient_pubkey_hex));
+    cJSON_AddItemToObject(filter, "#p", pvals);
+
+    if (mint_urls && mint_count > 0) {
+        cJSON* uvals = cJSON_CreateArray();
+        for (int i = 0; i < mint_count; i++) {
+            if (mint_urls[i]) cJSON_AddItemToArray(uvals, cJSON_CreateString(mint_urls[i]));
+        }
+        cJSON_AddItemToObject(filter, "#u", uvals);
+    }
+
+    if (since > 0) {
+        cJSON_AddNumberToObject(filter, "since", (double)since);
+    }
+
+    return filter;
+}

nostr_core/nip061.h

@@ -0,0 +1,104 @@
+/*
+ * NIP-61: Nutzaps
+ * https://github.com/nostr-protocol/nips/blob/master/61.md
+ */
+
+#ifndef NOSTR_NIP061_H
+#define NOSTR_NIP061_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <time.h>
+#include "nip001.h"
+#include "nip060.h"
+#include "nostr_common.h"
+#include "nostr_signer.h"
+#include "../cjson/cJSON.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define NOSTR_NIP61_NUTZAP_INFO_KIND 10019
+#define NOSTR_NIP61_NUTZAP_KIND 9321
+
+typedef struct {
+    char* url;
+    char** units;
+    int unit_count;
+} nostr_nip61_mint_entry_t;
+
+typedef struct {
+    char** relay_urls;
+    int relay_count;
+    nostr_nip61_mint_entry_t* mints;
+    int mint_count;
+    char pubkey[NOSTR_CASHU_PUBKEY_HEX_SIZE];
+} nostr_nip61_nutzap_info_t;
+
+typedef struct {
+    char* content;
+    nostr_cashu_proof_t* proofs;
+    int proof_count;
+    char* mint_url;
+    char recipient_pubkey[65];
+    char nutzapped_event_id[NOSTR_CASHU_EVENT_ID_HEX_SIZE];
+    char nutzapped_relay_hint[256];
+    int nutzapped_kind;
+} nostr_nip61_nutzap_data_t;
+
+cJSON* nostr_nip61_create_nutzap_info_event(const nostr_nip61_nutzap_info_t* info,
+                                            const unsigned char* private_key,
+                                            time_t timestamp);
+cJSON* nostr_nip61_create_nutzap_info_event_with_signer(const nostr_nip61_nutzap_info_t* info,
+                                                        nostr_signer_t* signer,
+                                                        time_t timestamp);
+
+int nostr_nip61_parse_nutzap_info_event(cJSON* event,
+                                        nostr_nip61_nutzap_info_t* info_out);
+
+void nostr_nip61_free_nutzap_info(nostr_nip61_nutzap_info_t* info);
+
+cJSON* nostr_nip61_create_nutzap_event(const nostr_nip61_nutzap_data_t* nutzap_data,
+                                       const unsigned char* sender_private_key,
+                                       time_t timestamp);
+cJSON* nostr_nip61_create_nutzap_event_with_signer(const nostr_nip61_nutzap_data_t* nutzap_data,
+                                                   nostr_signer_t* signer,
+                                                   time_t timestamp);
+
+int nostr_nip61_parse_nutzap_event(cJSON* event,
+                                   nostr_nip61_nutzap_data_t* nutzap_data_out);
+
+void nostr_nip61_free_nutzap_data(nostr_nip61_nutzap_data_t* data);
+
+cJSON* nostr_nip61_create_redemption_event(const char* nutzap_event_id,
+                                           const char* nutzap_relay_hint,
+                                           const char* sender_pubkey,
+                                           const char* created_token_event_id,
+                                           const char* created_token_relay_hint,
+                                           uint64_t amount,
+                                           const unsigned char* private_key,
+                                           time_t timestamp);
+cJSON* nostr_nip61_create_redemption_event_with_signer(const char* nutzap_event_id,
+                                                       const char* nutzap_relay_hint,
+                                                       const char* sender_pubkey,
+                                                       const char* created_token_event_id,
+                                                       const char* created_token_relay_hint,
+                                                       uint64_t amount,
+                                                       nostr_signer_t* signer,
+                                                       time_t timestamp);
+
+int nostr_nip61_verify_nutzap(cJSON* nutzap_event, cJSON* nutzap_info_event);
+
+cJSON* nostr_nip61_create_nutzap_info_filter(const char* pubkey_hex);
+
+cJSON* nostr_nip61_create_nutzap_filter(const char* recipient_pubkey_hex,
+                                        const char** mint_urls,
+                                        int mint_count,
+                                        time_t since);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_NIP061_H */

nostr_core/nostr_common.c

@@ -30,6 +30,60 @@ const char* nostr_strerror(int error_code) {
         case NOSTR_ERROR_NIP05_JSON_PARSE_FAILED: return "NIP-05: JSON parsing failed";
         case NOSTR_ERROR_NIP05_NAME_NOT_FOUND: return "NIP-05: Name not found in .well-known";
         case NOSTR_ERROR_NIP05_PUBKEY_MISMATCH: return "NIP-05: Public key mismatch";
+        case NOSTR_ERROR_EVENT_INVALID_STRUCTURE: return "Event has invalid structure";
+        case NOSTR_ERROR_EVENT_INVALID_ID: return "Event has invalid ID";
+        case NOSTR_ERROR_EVENT_INVALID_PUBKEY: return "Event has invalid public key";
+        case NOSTR_ERROR_EVENT_INVALID_SIGNATURE: return "Event has invalid signature";
+        case NOSTR_ERROR_EVENT_INVALID_CREATED_AT: return "Event has invalid timestamp";
+        case NOSTR_ERROR_EVENT_INVALID_KIND: return "Event has invalid kind";
+        case NOSTR_ERROR_EVENT_INVALID_TAGS: return "Event has invalid tags";
+        case NOSTR_ERROR_EVENT_INVALID_CONTENT: return "Event has invalid content";
+        case NOSTR_ERROR_NIP13_INSUFFICIENT: return "NIP-13: Insufficient PoW difficulty";
+        case NOSTR_ERROR_NIP13_NO_NONCE_TAG: return "NIP-13: Missing nonce tag";
+        case NOSTR_ERROR_NIP13_INVALID_NONCE_TAG: return "NIP-13: Invalid nonce tag format";
+        case NOSTR_ERROR_NIP13_TARGET_MISMATCH: return "NIP-13: Target difficulty mismatch";
+        case NOSTR_ERROR_NIP13_CALCULATION: return "NIP-13: PoW calculation error";
+        case NOSTR_ERROR_NIP42_INVALID_CHALLENGE: return "NIP-42: Invalid challenge";
+        case NOSTR_ERROR_NIP42_CHALLENGE_EXPIRED: return "NIP-42: Challenge expired";
+        case NOSTR_ERROR_NIP42_AUTH_EVENT_INVALID: return "NIP-42: Authentication event invalid";
+        case NOSTR_ERROR_NIP42_URL_MISMATCH: return "NIP-42: Relay URL mismatch";
+        case NOSTR_ERROR_NIP42_TIME_TOLERANCE: return "NIP-42: Timestamp outside tolerance";
+        case NOSTR_ERROR_NIP42_NOT_AUTHENTICATED: return "NIP-42: Client not authenticated";
+        case NOSTR_ERROR_NIP42_INVALID_MESSAGE_FORMAT: return "NIP-42: Invalid message format";
+        case NOSTR_ERROR_NIP42_CHALLENGE_TOO_SHORT: return "NIP-42: Challenge too short";
+        case NOSTR_ERROR_NIP42_CHALLENGE_TOO_LONG: return "NIP-42: Challenge too long";
+        case NOSTR_ERROR_NIP46_INVALID_BUNKER_URL: return "NIP-46: Invalid bunker URL";
+        case NOSTR_ERROR_NIP46_INVALID_NOSTRCONNECT: return "NIP-46: Invalid nostrconnect URL";
+        case NOSTR_ERROR_NIP46_INVALID_REQUEST: return "NIP-46: Invalid request payload";
+        case NOSTR_ERROR_NIP46_INVALID_RESPONSE: return "NIP-46: Invalid response payload";
+        case NOSTR_ERROR_NIP46_ENCRYPTION_FAILED: return "NIP-46: Encryption failed";
+        case NOSTR_ERROR_NIP46_DECRYPTION_FAILED: return "NIP-46: Decryption failed";
+        case NOSTR_ERROR_NIP46_CONNECTION_FAILED: return "NIP-46: Connection failed";
+        case NOSTR_ERROR_NIP46_TIMEOUT: return "NIP-46: Timeout";
+        case NOSTR_ERROR_NIP46_SECRET_MISMATCH: return "NIP-46: Secret mismatch";
+        case NOSTR_ERROR_NIP46_UNKNOWN_METHOD: return "NIP-46: Unknown method";
+        case NOSTR_ERROR_NIP46_AUTH_CHALLENGE: return "NIP-46: Auth challenge required";
+        case NOSTR_ERROR_NIP46_NOT_CONNECTED: return "NIP-46: Not connected";
+        case NOSTR_ERROR_NIP60_INVALID_WALLET: return "NIP-60: Invalid wallet event";
+        case NOSTR_ERROR_NIP60_INVALID_TOKEN: return "NIP-60: Invalid token event";
+        case NOSTR_ERROR_NIP60_INVALID_HISTORY: return "NIP-60: Invalid history event";
+        case NOSTR_ERROR_NIP60_INVALID_QUOTE: return "NIP-60: Invalid quote event";
+        case NOSTR_ERROR_NIP60_DECRYPT_FAILED: return "NIP-60: Decryption failed";
+        case NOSTR_ERROR_NIP60_INVALID_PROOFS: return "NIP-60: Invalid proofs payload";
+        case NOSTR_ERROR_NIP60_INSUFFICIENT_FUNDS: return "NIP-60: Insufficient funds";
+        case NOSTR_ERROR_NIP61_INVALID_INFO: return "NIP-61: Invalid info event";
+        case NOSTR_ERROR_NIP61_INVALID_NUTZAP: return "NIP-61: Invalid nutzap event";
+        case NOSTR_ERROR_NIP61_MINT_MISMATCH: return "NIP-61: Mint mismatch";
+        case NOSTR_ERROR_NIP61_PUBKEY_MISMATCH: return "NIP-61: Pubkey mismatch";
+        case NOSTR_ERROR_NIP61_VERIFICATION_FAILED: return "NIP-61: Verification failed";
+        case NOSTR_ERROR_CASHU_HTTP_FAILED: return "Cashu: HTTP request failed";
+        case NOSTR_ERROR_CASHU_JSON_PARSE_FAILED: return "Cashu: JSON parsing failed";
+        case NOSTR_ERROR_CASHU_MINT_ERROR: return "Cashu: Mint returned an error";
+        case NOSTR_ERROR_CASHU_QUOTE_NOT_PAID: return "Cashu: Quote not paid";
+        case NOSTR_ERROR_CASHU_QUOTE_EXPIRED: return "Cashu: Quote expired";
+        case NOSTR_ERROR_CASHU_PROOFS_SPENT: return "Cashu: One or more proofs are already spent";
+        case NOSTR_ERROR_CASHU_CRYPTO_FAILED: return "Cashu: Cryptographic operation failed";
+        case NOSTR_ERROR_CASHU_INVALID_KEYSET: return "Cashu: Invalid keyset";
         default: return "Unknown error";
     }
 }

nostr_core/nostr_common.h

@@ -27,7 +27,83 @@
 #define NOSTR_ERROR_NIP05_JSON_PARSE_FAILED -18
 #define NOSTR_ERROR_NIP05_NAME_NOT_FOUND -19
 #define NOSTR_ERROR_NIP05_PUBKEY_MISMATCH -20
+#define NOSTR_ERROR_EVENT_INVALID_STRUCTURE -30
+/* nsigner remote backend errors */
+#define NOSTR_ERROR_NSIGNER_POLICY_DENIED -2001
+#define NOSTR_ERROR_NSIGNER_INDEX_NOT_ALLOWED -2002
+#define NOSTR_ERROR_EVENT_INVALID_ID -31
+#define NOSTR_ERROR_EVENT_INVALID_PUBKEY -32
+#define NOSTR_ERROR_EVENT_INVALID_SIGNATURE -33
+#define NOSTR_ERROR_EVENT_INVALID_CREATED_AT -34
+#define NOSTR_ERROR_EVENT_INVALID_KIND -35
+#define NOSTR_ERROR_EVENT_INVALID_TAGS -36
+#define NOSTR_ERROR_EVENT_INVALID_CONTENT -37
 
+// Authentication Rules System Error Codes
+#define NOSTR_ERROR_AUTH_RULES_DISABLED -50
+#define NOSTR_ERROR_AUTH_RULES_DENIED -51
+#define NOSTR_ERROR_AUTH_RULES_DB_FAILED -52
+#define NOSTR_ERROR_AUTH_RULES_INVALID_RULE -53
+#define NOSTR_ERROR_AUTH_RULES_CACHE_FAILED -54
+#define NOSTR_ERROR_AUTH_RULES_BACKEND_NOT_FOUND -55
+
+// NIP-13 PoW-specific error codes
+#define NOSTR_ERROR_NIP13_INSUFFICIENT -100
+#define NOSTR_ERROR_NIP13_NO_NONCE_TAG -101
+#define NOSTR_ERROR_NIP13_INVALID_NONCE_TAG -102
+#define NOSTR_ERROR_NIP13_TARGET_MISMATCH -103
+#define NOSTR_ERROR_NIP13_CALCULATION -104
+
+// NIP-42 Authentication-specific error codes
+#define NOSTR_ERROR_NIP42_INVALID_CHALLENGE -200
+#define NOSTR_ERROR_NIP42_CHALLENGE_EXPIRED -201
+#define NOSTR_ERROR_NIP42_AUTH_EVENT_INVALID -202
+#define NOSTR_ERROR_NIP42_URL_MISMATCH -203
+#define NOSTR_ERROR_NIP42_TIME_TOLERANCE -204
+#define NOSTR_ERROR_NIP42_NOT_AUTHENTICATED -205
+#define NOSTR_ERROR_NIP42_INVALID_MESSAGE_FORMAT -206
+#define NOSTR_ERROR_NIP42_CHALLENGE_TOO_SHORT -207
+#define NOSTR_ERROR_NIP42_CHALLENGE_TOO_LONG -208
+
+// NIP-46 Remote Signing error codes
+#define NOSTR_ERROR_NIP46_INVALID_BUNKER_URL -300
+#define NOSTR_ERROR_NIP46_INVALID_NOSTRCONNECT -301
+#define NOSTR_ERROR_NIP46_INVALID_REQUEST -302
+#define NOSTR_ERROR_NIP46_INVALID_RESPONSE -303
+#define NOSTR_ERROR_NIP46_ENCRYPTION_FAILED -304
+#define NOSTR_ERROR_NIP46_DECRYPTION_FAILED -305
+#define NOSTR_ERROR_NIP46_CONNECTION_FAILED -306
+#define NOSTR_ERROR_NIP46_TIMEOUT -307
+#define NOSTR_ERROR_NIP46_SECRET_MISMATCH -308
+#define NOSTR_ERROR_NIP46_UNKNOWN_METHOD -309
+#define NOSTR_ERROR_NIP46_AUTH_CHALLENGE -310
+#define NOSTR_ERROR_NIP46_NOT_CONNECTED -311
+
+// NIP-60 Cashu Wallet error codes
+#define NOSTR_ERROR_NIP60_INVALID_WALLET -400
+#define NOSTR_ERROR_NIP60_INVALID_TOKEN -401
+#define NOSTR_ERROR_NIP60_INVALID_HISTORY -402
+#define NOSTR_ERROR_NIP60_INVALID_QUOTE -403
+#define NOSTR_ERROR_NIP60_DECRYPT_FAILED -404
+#define NOSTR_ERROR_NIP60_INVALID_PROOFS -405
+#define NOSTR_ERROR_NIP60_INSUFFICIENT_FUNDS -406
+
+// NIP-61 Nutzap error codes
+#define NOSTR_ERROR_NIP61_INVALID_INFO -410
+#define NOSTR_ERROR_NIP61_INVALID_NUTZAP -411
+#define NOSTR_ERROR_NIP61_MINT_MISMATCH -412
+#define NOSTR_ERROR_NIP61_PUBKEY_MISMATCH -413
+#define NOSTR_ERROR_NIP61_VERIFICATION_FAILED -414
+
+// Cashu Mint client error codes
+#define NOSTR_ERROR_CASHU_HTTP_FAILED -420
+#define NOSTR_ERROR_CASHU_JSON_PARSE_FAILED -421
+#define NOSTR_ERROR_CASHU_MINT_ERROR -422
+#define NOSTR_ERROR_CASHU_QUOTE_NOT_PAID -423
+#define NOSTR_ERROR_CASHU_QUOTE_EXPIRED -424
+#define NOSTR_ERROR_CASHU_PROOFS_SPENT -425
+#define NOSTR_ERROR_CASHU_CRYPTO_FAILED -426
+#define NOSTR_ERROR_CASHU_INVALID_KEYSET -427
 
 // Constants
 #define NOSTR_PRIVATE_KEY_SIZE 32
@@ -39,75 +115,20 @@
 #define NIP05_DEFAULT_TIMEOUT 10
 
 // NIP-04 Constants
-#define NOSTR_NIP04_MAX_PLAINTEXT_SIZE 16777216    // 16MB
+#define NOSTR_NIP04_MAX_PLAINTEXT_SIZE 1048576    // 1MB
 #define NOSTR_NIP04_MAX_ENCRYPTED_SIZE 22369621    // ~21.3MB (accounts for base64 overhead + IV)
 
-// NIP-44 Constants  
-#define NOSTR_NIP44_MAX_PLAINTEXT_SIZE 65536       // 64KB max plaintext (matches crypto header)
+// NIP-44 Constants
+#define NOSTR_NIP44_MAX_PLAINTEXT_SIZE 65535         // 64KB - 1 (NIP-44 spec compliant)
 
 // Forward declaration for cJSON (to avoid requiring cJSON.h in header)
 struct cJSON;
 
-// Relay query modes
-typedef enum {
-    RELAY_QUERY_FIRST_RESULT,   // Return as soon as first event is received
-    RELAY_QUERY_MOST_RECENT,    // Return the most recent event from all relays
-    RELAY_QUERY_ALL_RESULTS     // Return all unique events from all relays
-} relay_query_mode_t;
-
-// Publish result types
-typedef enum {
-    PUBLISH_SUCCESS,    // Event was accepted by relay
-    PUBLISH_REJECTED,   // Event was rejected by relay  
-    PUBLISH_TIMEOUT,    // No response within timeout
-    PUBLISH_ERROR       // Connection or other error
-} publish_result_t;
-
-// Progress callback function types
-typedef void (*relay_progress_callback_t)(
-    const char* relay_url,
-    const char* status,
-    const char* event_id,
-    int events_received,
-    int total_relays,
-    int completed_relays,
-    void* user_data);
-
-typedef void (*publish_progress_callback_t)(
-    const char* relay_url,
-    const char* status,
-    const char* message,
-    int success_count,
-    int total_relays,
-    int completed_relays,
-    void* user_data);
-
 // Function declarations
 const char* nostr_strerror(int error_code);
 
-// Library initialization functions  
+// Library initialization functions
 int nostr_init(void);
 void nostr_cleanup(void);
 
-// Relay query functions
-struct cJSON** synchronous_query_relays_with_progress(
-    const char** relay_urls,
-    int relay_count,
-    struct cJSON* filter,
-    relay_query_mode_t mode,
-    int* result_count,
-    int relay_timeout_seconds,
-    relay_progress_callback_t callback,
-    void* user_data);
-
-// Relay publish functions  
-publish_result_t* synchronous_publish_event_with_progress(
-    const char** relay_urls,
-    int relay_count,
-    struct cJSON* event,
-    int* success_count,
-    int relay_timeout_seconds,
-    publish_progress_callback_t callback,
-    void* user_data);
-
 #endif // NOSTR_COMMON_H

nostr_core/nostr_core.h

@@ -1,11 +1,170 @@
 #ifndef NOSTR_CORE_H
 #define NOSTR_CORE_H
 
-/**
- * NOSTR Core Library - Unified Header File
+// Version information (auto-updated by increment_and_push.sh)
+#define VERSION "v0.6.11"
+#define VERSION_MAJOR 0
+#define VERSION_MINOR 6
+#define VERSION_PATCH 11
+
+/*
+ * NOSTR Core Library - Complete API Reference
  * 
- * This file provides a single include point for all NOSTR Core functionality.
- * Include this file to access all available NIPs and core functions.
+ * This header includes ALL library functionality. For modular includes,
+ * use individual headers instead.
+ * 
+ * ============================================================================
+ * QUICK FUNCTION REFERENCE - Find what you need fast!
+ * ============================================================================
+ * 
+ * EVENT OPERATIONS (NIP-01):
+ *   - nostr_create_and_sign_event()     -> Create and sign new Nostr events
+ *   - nostr_validate_event()            -> Validate complete Nostr event 
+ *   - nostr_validate_event_structure()  -> Check event structure only
+ *   - nostr_verify_event_signature()    -> Verify cryptographic signature
+ * 
+ * CRYPTOGRAPHIC HASHING:
+ *   - nostr_sha256()                    -> Single-call SHA-256 hash
+ *   - nostr_sha256_init()               -> Initialize streaming SHA-256 context
+ *   - nostr_sha256_update()             -> Process data chunks incrementally
+ *   - nostr_sha256_final()              -> Finalize hash and clear context
+ *   - nostr_sha256_file_stream()        -> Hash large files efficiently (NEW!)
+ *   - nostr_sha512()                    -> SHA-512 hash function
+ *   - nostr_hmac_sha256()               -> HMAC with SHA-256
+ *   - nostr_hmac_sha512()               -> HMAC with SHA-512
+ * 
+ * DIGITAL SIGNATURES & KEYS:
+ *   - nostr_schnorr_sign()              -> Create Schnorr signatures
+ *   - nostr_ec_public_key_from_private_key() -> Generate public keys
+ *   - nostr_ec_private_key_verify()     -> Validate private key format
+ *   - nostr_ec_sign()                   -> ECDSA signature creation
+ *   - nostr_rfc6979_generate_k()        -> Deterministic nonce generation
+ * 
+ * NIP-04 ENCRYPTION (Legacy):
+ *   - nostr_nip04_encrypt()             -> Encrypt messages (AES-256-CBC)
+ *   - nostr_nip04_decrypt()             -> Decrypt messages (AES-256-CBC)
+ * 
+ * NIP-44 ENCRYPTION (Modern - Recommended):
+ *   - nostr_nip44_encrypt()             -> Encrypt with ChaCha20 + HMAC
+ *   - nostr_nip44_encrypt_with_nonce()  -> Encrypt with specific nonce (testing)
+ *   - nostr_nip44_decrypt()             -> Decrypt ChaCha20 + HMAC messages
+ *
+ * NIP-46 REMOTE SIGNING:
+ *   - nostr_nip46_parse_bunker_url()    -> Parse bunker:// connection tokens
+ *   - nostr_nip46_parse_nostrconnect_url() -> Parse nostrconnect:// connection tokens
+ *   - nostr_nip46_create_request_event() -> Create encrypted kind 24133 request events
+ *   - nostr_nip46_create_response_event() -> Create encrypted kind 24133 response events
+ *   - nostr_nip46_signer_handle_request() -> Handle signer-side RPC requests
+ *
+ * NIP-59 GIFT WRAP:
+ *   - nostr_nip59_create_rumor()        -> Create unsigned event (rumor)
+ *   - nostr_nip59_create_seal()         -> Seal rumor with sender's key (kind 13)
+ *   - nostr_nip59_create_gift_wrap()    -> Wrap seal with random key (kind 1059)
+ *   - nostr_nip59_unwrap_gift()         -> Unwrap gift wrap to get seal
+ *   - nostr_nip59_unseal_rumor()        -> Unseal to get original rumor
+ *
+ * NIP-17 PRIVATE DIRECT MESSAGES:
+ *   - nostr_nip17_create_chat_event()   -> Create chat message (kind 14)
+ *   - nostr_nip17_create_file_event()   -> Create file message (kind 15)
+ *   - nostr_nip17_create_relay_list_event() -> Create DM relay list (kind 10050)
+ *   - nostr_nip17_send_dm()             -> Send DM to multiple recipients
+ *   - nostr_nip17_receive_dm()          -> Receive and decrypt DM
+ *   - nostr_nip17_extract_dm_relays()   -> Extract relay URLs from kind 10050
+ *
+ * NIP-42 AUTHENTICATION:
+ *   - nostr_nip42_create_auth_event()   -> Create authentication event (kind 22242)
+ *   - nostr_nip42_verify_auth_event()   -> Verify authentication event (relay-side)
+ *   - nostr_nip42_generate_challenge()  -> Generate challenge string (relay-side)
+ *   - nostr_ws_authenticate()           -> Authenticate WebSocket client
+ *   - nostr_ws_get_auth_state()         -> Get client authentication state
+ *
+ * BIP39 MNEMONICS:
+ *   - nostr_bip39_mnemonic_from_bytes() -> Generate mnemonic from entropy
+ *   - nostr_bip39_mnemonic_validate()   -> Validate mnemonic phrase
+ *   - nostr_bip39_mnemonic_to_seed()    -> Convert mnemonic to seed
+ * 
+ * BIP32 HD WALLETS:
+ *   - nostr_bip32_key_from_seed()       -> Create master key from seed
+ *   - nostr_bip32_derive_child()        -> Derive child key from parent
+ *   - nostr_bip32_derive_path()         -> Derive keys from derivation path
+ * 
+ * KEY DERIVATION:
+ *   - nostr_hkdf()                      -> HKDF key derivation (full)
+ *   - nostr_hkdf_extract()              -> HKDF extract step only
+ *   - nostr_hkdf_expand()               -> HKDF expand step only
+ *   - nostr_pbkdf2_hmac_sha512()        -> PBKDF2 with HMAC-SHA512
+ *   - ecdh_shared_secret()              -> ECDH shared secret computation
+ * 
+ * UTILITIES & ENCODING:
+ *   - nostr_bytes_to_hex()              -> Convert bytes to hex string
+ *   - nostr_hex_to_bytes()              -> Convert hex string to bytes
+ *   - base64_encode()                   -> Base64 encoding
+ *   - base64_decode()                   -> Base64 decoding
+ *
+ * REQUEST VALIDATION & AUTHENTICATION:
+ *   - nostr_validate_request()          -> Unified request validation (events + auth rules)
+ *   - nostr_request_validator_init()    -> Initialize authentication system
+ *   - nostr_auth_check_upload()         -> Validate file upload requests
+ *   - nostr_auth_check_delete()         -> Validate file delete requests
+ *   - nostr_auth_check_publish()        -> Validate event publish requests
+ *   - nostr_auth_rule_add()             -> Add authentication rule
+ *   - nostr_auth_rule_remove()          -> Remove authentication rule
+ *
+ * RELAY OPERATIONS:
+ *   - synchronous_query_relays_with_progress() -> One-off query from multiple relays
+ *   - synchronous_publish_event_with_progress() -> One-off publish to multiple relays
+ * *
+ * RELAY POOL OPERATIONS:
+ *   - nostr_relay_pool_create()         -> Create relay pool for persistent connections
+ *   - nostr_relay_pool_subscribe()      -> Subscribe to events with callbacks
+ *   - nostr_relay_pool_run()            -> Run event loop for receiving events
+
+ * SYSTEM FUNCTIONS:
+ *   - nostr_crypto_init()               -> Initialize crypto subsystem
+ *   - nostr_crypto_cleanup()            -> Cleanup crypto subsystem
+ * 
+ * ============================================================================
+ * USAGE EXAMPLES:
+ * ============================================================================
+ * 
+ * Basic Event Creation:
+ *   cJSON* event = nostr_create_and_sign_event(1, "Hello Nostr!", NULL, private_key, time(NULL));
+ *   if (nostr_validate_event(event) == NOSTR_SUCCESS) { ... }
+ * 
+ * Streaming SHA-256 (for large files):
+ *   nostr_sha256_ctx_t ctx;
+ *   nostr_sha256_init(&ctx);
+ *   // Process data in chunks...
+ *   nostr_sha256_update(&ctx, data, data_size);
+ *   nostr_sha256_final(&ctx, hash_output);
+ * 
+ * File Hashing:
+ *   unsigned char file_hash[32];
+ *   nostr_sha256_file_stream("large_video.mp4", file_hash);
+ * 
+ * Modern Encryption (NIP-44):
+ *   nostr_nip44_encrypt(sender_key, recipient_pubkey, "secret message", output, sizeof(output));
+ * 
+ * HD Wallet Derivation:
+ *   nostr_bip32_key_from_seed(seed, 64, &master_key);
+ *   uint32_t path[] = {44, 1237, 0, 0, 0}; // m/44'/1237'/0'/0/0
+ *   nostr_bip32_derive_path(&master_key, path, 5, &derived_key);
+ *
+ * Client Authentication (NIP-42):
+ *   cJSON* auth_event = nostr_nip42_create_auth_event(challenge, relay_url, private_key, 0);
+ *   nostr_ws_authenticate(client, private_key, 600); // Auto-authenticate WebSocket
+ *
+ * Private Direct Messages (NIP-17):
+ *   // Create and send a DM
+ *   cJSON* dm_event = nostr_nip17_create_chat_event("Hello!", &recipient_pubkey, 1, NULL, NULL, NULL, sender_pubkey);
+ *   cJSON* gift_wraps[10];
+ *   int count = nostr_nip17_send_dm(dm_event, &recipient_pubkey, 1, sender_privkey, gift_wraps, 10);
+ *   // Publish gift_wraps[0] to recipient's relays
+ *
+ *   // Receive a DM
+ *   cJSON* decrypted_dm = nostr_nip17_receive_dm(received_gift_wrap, recipient_privkey);
+ *
+ * ============================================================================
  */
 
 #ifdef __cplusplus
@@ -15,16 +174,254 @@ extern "C" {
 // Core common definitions and utilities
 #include "nostr_common.h"
 #include "utils.h"
+#include "nostr_signer.h"
 
 // NIP implementations
 #include "nip001.h"  // Basic Protocol
+#include "nip003.h"  // OpenTimestamps
 #include "nip004.h"  // Encryption (legacy)
 #include "nip005.h"  // DNS-based identifiers
 #include "nip006.h"  // Key derivation from mnemonic
 #include "nip011.h"  // Relay information document
 #include "nip013.h"  // Proof of Work
+#include "nip017.h"  // Private Direct Messages
 #include "nip019.h"  // Bech32 encoding (nsec/npub)
+#include "nip021.h"  // nostr: URI scheme
+#include "nip042.h"  // Authentication of clients to relays
 #include "nip044.h"  // Encryption (modern)
+#include "nip046.h"  // Remote signing
+#include "nip059.h"  // Gift Wrap
+#include "nip060.h"  // Cashu Wallet
+#include "nip061.h"  // Nutzaps
+#include "cashu_mint.h"  // Cashu mint HTTP client
+
+#include "nostr_http.h"  // Shared HTTP client
+#include "blossom_client.h"  // Blossom HTTP client
+
+// Authentication and request validation system
+#include "request_validator.h"  // Request validation and authentication rules
+
+// Logging callback API
+#include "nostr_log.h"
+
+// Relay pool types and functions
+typedef enum {
+    NOSTR_POOL_RELAY_DISCONNECTED = 0,
+    NOSTR_POOL_RELAY_CONNECTING = 1,
+    NOSTR_POOL_RELAY_CONNECTED = 2,
+    NOSTR_POOL_RELAY_ERROR = -1
+} nostr_pool_relay_status_t;
+
+// EOSE result mode for subscriptions
+typedef enum {
+    NOSTR_POOL_EOSE_FULL_SET,      // Wait for all relays, return all events
+    NOSTR_POOL_EOSE_MOST_RECENT,   // Wait for all relays, return most recent event
+    NOSTR_POOL_EOSE_FIRST          // Return results on first EOSE (fastest response)
+} nostr_pool_eose_result_mode_t;
+
+typedef struct {
+    int connection_attempts;
+    int connection_failures;
+    int events_received;
+    int events_published;
+    int events_published_ok;
+    int events_published_failed;
+    time_t last_event_time;
+    time_t connection_uptime_start;
+    double ping_latency_avg;
+    double ping_latency_min;
+    double ping_latency_max;
+    double ping_latency_current;
+    int ping_samples;
+    double query_latency_avg;
+    double query_latency_min;
+    double query_latency_max;
+    int query_samples;
+    double publish_latency_avg;
+    int publish_samples;
+} nostr_relay_stats_t;
+
+typedef struct nostr_relay_pool nostr_relay_pool_t;
+typedef struct nostr_pool_subscription nostr_pool_subscription_t;
+
+// Reconnection configuration
+typedef struct {
+    int enable_auto_reconnect;             // 1 = enable, 0 = disable
+    int max_reconnect_attempts;            // Max attempts per relay
+    int initial_reconnect_delay_ms;        // Initial delay between attempts
+    int max_reconnect_delay_ms;            // Max delay (cap exponential backoff)
+    int reconnect_backoff_multiplier;      // Delay multiplier
+    int reconnect_reset_stability_seconds; // Connected time required before resetting reconnect_attempts
+    int ping_interval_seconds;             // How often to ping (0 = disable)
+    int pong_timeout_seconds;              // How long to wait for pong before reconnecting
+} nostr_pool_reconnect_config_t;
+
+// Relay pool management functions
+nostr_relay_pool_t* nostr_relay_pool_create(nostr_pool_reconnect_config_t* config);
+nostr_pool_reconnect_config_t* nostr_pool_reconnect_config_default(void);
+int nostr_relay_pool_add_relay(nostr_relay_pool_t* pool, const char* relay_url);
+int nostr_relay_pool_remove_relay(nostr_relay_pool_t* pool, const char* relay_url);
+int nostr_relay_pool_set_auth(nostr_relay_pool_t* pool, const unsigned char* private_key, int enable);
+int nostr_relay_pool_set_auth_with_signer(nostr_relay_pool_t* pool, nostr_signer_t* signer, int enable);
+void nostr_relay_pool_destroy(nostr_relay_pool_t* pool);
+
+// Subscription management
+nostr_pool_subscription_t* nostr_relay_pool_subscribe(
+    nostr_relay_pool_t* pool,
+    const char** relay_urls,
+    int relay_count,
+    cJSON* filter,
+    void (*on_event)(cJSON* event, const char* relay_url, void* user_data),
+    void (*on_eose)(cJSON** events, int event_count, void* user_data),
+    void* user_data,
+    int close_on_eose,
+    int enable_deduplication,
+    nostr_pool_eose_result_mode_t result_mode,
+    int relay_timeout_seconds,
+    int eose_timeout_seconds);
+int nostr_pool_subscription_close(nostr_pool_subscription_t* subscription);
+
+// Backward compatibility wrapper
+nostr_pool_subscription_t* nostr_relay_pool_subscribe_compat(
+    nostr_relay_pool_t* pool,
+    const char** relay_urls,
+    int relay_count,
+    cJSON* filter,
+    void (*on_event)(cJSON* event, const char* relay_url, void* user_data),
+    void (*on_eose)(void* user_data),
+    void* user_data,
+    int close_on_eose);
+
+// Event loop functions
+int nostr_relay_pool_run(nostr_relay_pool_t* pool, int timeout_ms);
+int nostr_relay_pool_poll(nostr_relay_pool_t* pool, int timeout_ms);
+
+// Synchronous query/publish functions
+cJSON** nostr_relay_pool_query_sync(
+    nostr_relay_pool_t* pool,
+    const char** relay_urls,
+    int relay_count,
+    cJSON* filter,
+    int* event_count,
+    int timeout_ms);
+// Same as above but also reports whether all relays sent EOSE (vs timed out).
+// out_got_eose is set to 1 if all connected relays sent EOSE, 0 if any timed
+// out. May be NULL if the caller doesn't care.
+cJSON** nostr_relay_pool_query_sync_with_eose(
+    nostr_relay_pool_t* pool,
+    const char** relay_urls,
+    int relay_count,
+    cJSON* filter,
+    int* event_count,
+    int timeout_ms,
+    int* out_got_eose);
+cJSON* nostr_relay_pool_get_event(
+    nostr_relay_pool_t* pool,
+    const char** relay_urls,
+    int relay_count,
+    cJSON* filter,
+    int timeout_ms);
+// Async publish callback typedef
+typedef void (*publish_response_callback_t)(
+    const char* relay_url,
+    const char* event_id,
+    int success,           // 1 for OK, 0 for rejection
+    const char* message,   // Error message if rejected, NULL if success
+    void* user_data
+);
+
+// Async publish function (only async version available)
+int nostr_relay_pool_publish_async(
+    nostr_relay_pool_t* pool,
+    const char** relay_urls,
+    int relay_count,
+    cJSON* event,
+    publish_response_callback_t callback,
+    void* user_data);
+
+// Status and statistics functions
+nostr_pool_relay_status_t nostr_relay_pool_get_relay_status(
+    nostr_relay_pool_t* pool,
+    const char* relay_url);
+int nostr_relay_pool_list_relays(
+    nostr_relay_pool_t* pool,
+    char*** relay_urls,
+    nostr_pool_relay_status_t** statuses);
+const nostr_relay_stats_t* nostr_relay_pool_get_relay_stats(
+    nostr_relay_pool_t* pool,
+    const char* relay_url);
+int nostr_relay_pool_reset_relay_stats(
+    nostr_relay_pool_t* pool,
+    const char* relay_url);
+double nostr_relay_pool_get_relay_query_latency(
+    nostr_relay_pool_t* pool,
+    const char* relay_url);
+const char* nostr_relay_pool_get_relay_last_publish_error(
+    nostr_relay_pool_t* pool,
+    const char* relay_url);
+const char* nostr_relay_pool_get_relay_last_connection_error(
+    nostr_relay_pool_t* pool,
+    const char* relay_url);
+double nostr_relay_pool_get_relay_ping_latency(
+    nostr_relay_pool_t* pool,
+    const char* relay_url);
+
+// Synchronous relay operations (one-off queries/publishes)
+typedef enum {
+    RELAY_QUERY_FIRST_RESULT,   // Return as soon as first event is received
+    RELAY_QUERY_MOST_RECENT,    // Return the most recent event from all relays
+    RELAY_QUERY_ALL_RESULTS     // Return all unique events from all relays
+} relay_query_mode_t;
+
+typedef enum {
+    PUBLISH_SUCCESS,    // Event was accepted by relay
+    PUBLISH_REJECTED,   // Event was rejected by relay
+    PUBLISH_TIMEOUT,    // No response within timeout
+    PUBLISH_ERROR       // Connection or other error
+} publish_result_t;
+
+typedef void (*relay_progress_callback_t)(
+    const char* relay_url,
+    const char* status,
+    const char* event_id,
+    int events_received,
+    int total_relays,
+    int completed_relays,
+    void* user_data);
+
+typedef void (*publish_progress_callback_t)(
+    const char* relay_url,
+    const char* status,
+    const char* message,
+    int success_count,
+    int total_relays,
+    int completed_relays,
+    void* user_data);
+
+// Synchronous relay query functions
+struct cJSON** synchronous_query_relays_with_progress(
+    const char** relay_urls,
+    int relay_count,
+    struct cJSON* filter,
+    relay_query_mode_t mode,
+    int* result_count,
+    int relay_timeout_seconds,
+    relay_progress_callback_t callback,
+    void* user_data,
+    int nip42_enabled,
+    const unsigned char* private_key);
+
+// Synchronous relay publish functions
+publish_result_t* synchronous_publish_event_with_progress(
+    const char** relay_urls,
+    int relay_count,
+    struct cJSON* event,
+    int* success_count,
+    int relay_timeout_seconds,
+    publish_progress_callback_t callback,
+    void* user_data,
+    int nip42_enabled,
+    const unsigned char* private_key);
 
 // Relay communication functions are defined in nostr_common.h
 // WebSocket functions are defined in nostr_common.h

nostr_core/nostr_http.c

@@ -0,0 +1,295 @@
+/*
+ * NOSTR Core Library - Shared HTTP Client
+ */
+
+#include "nostr_http.h"
+
+#include <curl/curl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <unistd.h>
+
+typedef struct {
+    char* data;
+    size_t len;
+    size_t cap;
+    size_t max_bytes;
+    int truncated;
+} nostr_http_buffer_t;
+
+static char* nostr_http_strdup_local(const char* s) {
+    if (!s) return NULL;
+    size_t n = strlen(s);
+    char* out = (char*)malloc(n + 1U);
+    if (!out) return NULL;
+    memcpy(out, s, n + 1U);
+    return out;
+}
+
+static char g_ca_bundle_path[512] = {0};
+
+static int append_bytes(nostr_http_buffer_t* b, const void* src, size_t n) {
+    if (!b || !src || n == 0) return 1;
+
+    if (b->max_bytes > 0 && b->len >= b->max_bytes) {
+        b->truncated = 1;
+        return 1;
+    }
+
+    size_t to_copy = n;
+    if (b->max_bytes > 0) {
+        size_t remaining = b->max_bytes - b->len;
+        if (to_copy > remaining) {
+            to_copy = remaining;
+            b->truncated = 1;
+        }
+    }
+
+    if (b->len + to_copy + 1U > b->cap) {
+        size_t new_cap = b->cap == 0 ? 1024U : b->cap;
+        while (new_cap < b->len + to_copy + 1U) {
+            new_cap *= 2U;
+        }
+        char* p = (char*)realloc(b->data, new_cap);
+        if (!p) return 0;
+        b->data = p;
+        b->cap = new_cap;
+    }
+
+    memcpy(b->data + b->len, src, to_copy);
+    b->len += to_copy;
+    b->data[b->len] = '\0';
+    return 1;
+}
+
+static size_t write_cb(void* contents, size_t size, size_t nmemb, void* userp) {
+    nostr_http_buffer_t* rb = (nostr_http_buffer_t*)userp;
+    size_t total = size * nmemb;
+    if (!rb || total == 0) return total;
+    if (!append_bytes(rb, contents, total)) return 0;
+    return total;
+}
+
+static size_t header_cb(void* contents, size_t size, size_t nmemb, void* userp) {
+    nostr_http_buffer_t* hb = (nostr_http_buffer_t*)userp;
+    size_t total = size * nmemb;
+    if (!hb || total == 0) return total;
+    if (!append_bytes(hb, contents, total)) return 0;
+    return total;
+}
+
+void nostr_http_set_ca_bundle(const char* ca_bundle_path) {
+    if (!ca_bundle_path || ca_bundle_path[0] == '\0') {
+        g_ca_bundle_path[0] = '\0';
+        return;
+    }
+    strncpy(g_ca_bundle_path, ca_bundle_path, sizeof(g_ca_bundle_path) - 1);
+    g_ca_bundle_path[sizeof(g_ca_bundle_path) - 1] = '\0';
+}
+
+const char* nostr_http_detect_ca_bundle(void) {
+    const char* env = getenv("SSL_CERT_FILE");
+    if (env && env[0] != '\0' && access(env, R_OK) == 0) {
+        return env;
+    }
+
+    static const char* candidates[] = {
+        "/etc/ssl/certs/ca-certificates.crt",
+        "/etc/ssl/cert.pem",
+        "/etc/pki/tls/certs/ca-bundle.crt",
+        "/etc/ssl/ca-bundle.pem"
+    };
+
+    for (size_t i = 0; i < sizeof(candidates) / sizeof(candidates[0]); i++) {
+        if (access(candidates[i], R_OK) == 0) {
+            return candidates[i];
+        }
+    }
+    return NULL;
+}
+
+int nostr_http_request(const nostr_http_request_t* req, nostr_http_response_t* resp) {
+    if (!req || !req->url || !resp) return NOSTR_ERROR_INVALID_INPUT;
+
+    memset(resp, 0, sizeof(*resp));
+
+    CURL* curl = curl_easy_init();
+    if (!curl) return NOSTR_ERROR_NETWORK_FAILED;
+
+    const char* method = (req->method && req->method[0] != '\0') ? req->method : "GET";
+    int timeout = req->timeout_seconds > 0 ? req->timeout_seconds : 30;
+    int follow = req->follow_redirects;
+    if (follow != 0 && follow != 1) follow = 1;
+    int max_redirs = req->max_redirects > 0 ? req->max_redirects : 3;
+    const char* user_agent = (req->user_agent && req->user_agent[0] != '\0') ? req->user_agent : "nostr-core/1.0";
+
+    nostr_http_buffer_t body = {0};
+    body.max_bytes = req->max_response_bytes;
+
+    nostr_http_buffer_t headers = {0};
+
+    struct curl_slist* header_list = NULL;
+    if (req->headers) {
+        for (const char** h = req->headers; *h; h++) {
+            if ((*h)[0] != '\0') header_list = curl_slist_append(header_list, *h);
+        }
+    }
+
+    curl_easy_setopt(curl, CURLOPT_URL, req->url);
+    curl_easy_setopt(curl, CURLOPT_TIMEOUT, (long)timeout);
+    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, (long)follow);
+    curl_easy_setopt(curl, CURLOPT_MAXREDIRS, (long)max_redirs);
+    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
+    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 2L);
+    curl_easy_setopt(curl, CURLOPT_USERAGENT, user_agent);
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_cb);
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &body);
+
+    if (req->capture_headers) {
+        curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, header_cb);
+        curl_easy_setopt(curl, CURLOPT_HEADERDATA, &headers);
+    }
+
+    if (header_list) {
+        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, header_list);
+    }
+
+    if (g_ca_bundle_path[0] != '\0') {
+        curl_easy_setopt(curl, CURLOPT_CAINFO, g_ca_bundle_path);
+    }
+
+    if (strcasecmp(method, "GET") == 0) {
+        curl_easy_setopt(curl, CURLOPT_HTTPGET, 1L);
+    } else if (strcasecmp(method, "POST") == 0) {
+        curl_easy_setopt(curl, CURLOPT_POST, 1L);
+        if (req->body && req->body_len > 0) {
+            curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)req->body_len);
+            curl_easy_setopt(curl, CURLOPT_POSTFIELDS, (const char*)req->body);
+        } else {
+            curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "");
+            curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, 0L);
+        }
+        // Disable Expect: 100-continue
+        header_list = curl_slist_append(header_list, "Expect:");
+        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, header_list);
+    } else if (strcasecmp(method, "HEAD") == 0) {
+        curl_easy_setopt(curl, CURLOPT_NOBODY, 1L);
+        curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "HEAD");
+    } else {
+        curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, method);
+        if (req->body && req->body_len > 0) {
+            curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (long)req->body_len);
+            curl_easy_setopt(curl, CURLOPT_POSTFIELDS, (const char*)req->body);
+        }
+    }
+
+    CURLcode rc = curl_easy_perform(curl);
+    long status = 0;
+    char* content_type = NULL;
+    char* content_type_copy = NULL;
+    curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &status);
+    curl_easy_getinfo(curl, CURLINFO_CONTENT_TYPE, &content_type);
+    if (content_type && content_type[0] != '\0') {
+        content_type_copy = nostr_http_strdup_local(content_type);
+    }
+
+    if (header_list) curl_slist_free_all(header_list);
+    curl_easy_cleanup(curl);
+
+    if (rc != CURLE_OK) {
+        free(body.data);
+        free(headers.data);
+        free(content_type_copy);
+        return NOSTR_ERROR_NETWORK_FAILED;
+    }
+
+    resp->status_code = status;
+    resp->body = body.data ? body.data : nostr_http_strdup_local("");
+    resp->body_len = body.data ? body.len : 0;
+    resp->headers_raw = headers.data;
+    resp->content_type = content_type_copy;
+    resp->truncated = body.truncated;
+
+    if (!resp->body) {
+        free(resp->headers_raw);
+        free(resp->content_type);
+        memset(resp, 0, sizeof(*resp));
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    return NOSTR_SUCCESS;
+}
+
+void nostr_http_response_free(nostr_http_response_t* resp) {
+    if (!resp) return;
+    free(resp->body);
+    free(resp->content_type);
+    free(resp->headers_raw);
+    memset(resp, 0, sizeof(*resp));
+}
+
+int nostr_http_get(const char* url, int timeout_seconds, char** body_out, long* status_out) {
+    if (!url || !body_out) return NOSTR_ERROR_INVALID_INPUT;
+
+    *body_out = NULL;
+    if (status_out) *status_out = 0;
+
+    nostr_http_request_t req;
+    memset(&req, 0, sizeof(req));
+    req.method = "GET";
+    req.url = url;
+    req.timeout_seconds = timeout_seconds;
+    req.follow_redirects = 1;
+    req.max_redirects = 3;
+
+    nostr_http_response_t resp;
+    int rc = nostr_http_request(&req, &resp);
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    if (status_out) *status_out = resp.status_code;
+    *body_out = resp.body;
+    free(resp.content_type);
+    free(resp.headers_raw);
+    return NOSTR_SUCCESS;
+}
+
+int nostr_http_post_json(const char* url,
+                         const char* json_body,
+                         int timeout_seconds,
+                         char** body_out,
+                         long* status_out) {
+    if (!url || !body_out) return NOSTR_ERROR_INVALID_INPUT;
+
+    *body_out = NULL;
+    if (status_out) *status_out = 0;
+
+    const char* headers[] = {
+        "Accept: application/json",
+        "Content-Type: application/json",
+        NULL
+    };
+
+    const char* payload = json_body ? json_body : "{}";
+
+    nostr_http_request_t req;
+    memset(&req, 0, sizeof(req));
+    req.method = "POST";
+    req.url = url;
+    req.headers = headers;
+    req.body = (const unsigned char*)payload;
+    req.body_len = strlen(payload);
+    req.timeout_seconds = timeout_seconds;
+    req.follow_redirects = 1;
+    req.max_redirects = 3;
+
+    nostr_http_response_t resp;
+    int rc = nostr_http_request(&req, &resp);
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    if (status_out) *status_out = resp.status_code;
+    *body_out = resp.body;
+    free(resp.content_type);
+    free(resp.headers_raw);
+    return NOSTR_SUCCESS;
+}

nostr_core/nostr_http.h

@@ -0,0 +1,55 @@
+/*
+ * NOSTR Core Library - Shared HTTP Client
+ */
+
+#ifndef NOSTR_HTTP_H
+#define NOSTR_HTTP_H
+
+#include "nostr_common.h"
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    char* body;
+    size_t body_len;
+    long status_code;
+    char* content_type;
+    char* headers_raw;
+    int truncated;
+} nostr_http_response_t;
+
+typedef struct {
+    const char* method;
+    const char* url;
+    const char** headers;
+    const unsigned char* body;
+    size_t body_len;
+    int timeout_seconds;
+    size_t max_response_bytes;
+    int follow_redirects;
+    int max_redirects;
+    const char* user_agent;
+    int capture_headers;
+} nostr_http_request_t;
+
+void nostr_http_set_ca_bundle(const char* ca_bundle_path);
+const char* nostr_http_detect_ca_bundle(void);
+
+int nostr_http_request(const nostr_http_request_t* req, nostr_http_response_t* resp);
+void nostr_http_response_free(nostr_http_response_t* resp);
+
+int nostr_http_get(const char* url, int timeout_seconds, char** body_out, long* status_out);
+int nostr_http_post_json(const char* url,
+                         const char* json_body,
+                         int timeout_seconds,
+                         char** body_out,
+                         long* status_out);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_HTTP_H */

nostr_core/nostr_log.c

@@ -0,0 +1,54 @@
+#include "nostr_log.h"
+
+#include <stdio.h>
+
+#define NOSTR_LOG_BUFFER_SIZE 4096
+
+static nostr_log_callback_t g_log_callback = NULL;
+static void* g_log_user_data = NULL;
+static int g_log_min_level = NOSTR_LOG_LEVEL_ERROR;
+
+void nostr_set_log_callback(nostr_log_callback_t cb, void* user_data) {
+    g_log_callback = cb;
+    g_log_user_data = user_data;
+}
+
+void nostr_set_log_level(nostr_log_level_t min_level) {
+    if (min_level < NOSTR_LOG_LEVEL_ERROR) {
+        g_log_min_level = NOSTR_LOG_LEVEL_ERROR;
+        return;
+    }
+    if (min_level > NOSTR_LOG_LEVEL_TRACE) {
+        g_log_min_level = NOSTR_LOG_LEVEL_TRACE;
+        return;
+    }
+    g_log_min_level = (int)min_level;
+}
+
+void nostr_log_vemitf(int level, const char* component, const char* format, va_list args) {
+    if (!g_log_callback || !format) {
+        return;
+    }
+    if (level < g_log_min_level) {
+        return;
+    }
+
+    char message[NOSTR_LOG_BUFFER_SIZE];
+    int written = vsnprintf(message, sizeof(message), format, args);
+    if (written < 0) {
+        return;
+    }
+    message[sizeof(message) - 1] = '\0';
+
+    g_log_callback(level,
+                   component ? component : "unknown",
+                   message,
+                   g_log_user_data);
+}
+
+void nostr_log_emitf(int level, const char* component, const char* format, ...) {
+    va_list args;
+    va_start(args, format);
+    nostr_log_vemitf(level, component, format, args);
+    va_end(args);
+}

nostr_core/nostr_log.h

@@ -0,0 +1,35 @@
+#ifndef NOSTR_LOG_H
+#define NOSTR_LOG_H
+
+#include <stdarg.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum {
+    NOSTR_LOG_LEVEL_ERROR = 1,
+    NOSTR_LOG_LEVEL_WARN = 2,
+    NOSTR_LOG_LEVEL_INFO = 3,
+    NOSTR_LOG_LEVEL_DEBUG = 4,
+    NOSTR_LOG_LEVEL_TRACE = 5
+} nostr_log_level_t;
+
+typedef void (*nostr_log_callback_t)(
+    int level,
+    const char* component,
+    const char* message,
+    void* user_data
+);
+
+void nostr_set_log_callback(nostr_log_callback_t cb, void* user_data);
+void nostr_set_log_level(nostr_log_level_t min_level);
+
+void nostr_log_emitf(int level, const char* component, const char* format, ...);
+void nostr_log_vemitf(int level, const char* component, const char* format, va_list args);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_LOG_H */

nostr_core/nostr_platform.h

@@ -0,0 +1,20 @@
+#ifndef NOSTR_PLATFORM_H
+#define NOSTR_PLATFORM_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Fill buffer with cryptographically secure random bytes.
+ * Returns 0 on success, -1 on failure.
+ */
+int nostr_platform_random(unsigned char *buf, size_t len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_PLATFORM_H */

nostr_core/nostr_signer.c

@@ -0,0 +1,880 @@
+#include "nostr_signer.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "utils.h"
+#include "nip004.h"
+#include "nip044.h"
+
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+#include "nsigner_transport.h"
+#include "nsigner_client.h"
+#endif
+
+typedef enum {
+    NOSTR_SIGNER_BACKEND_LOCAL = 1,
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE = 2,
+#endif
+} nostr_signer_backend_t;
+
+struct nostr_signer {
+    nostr_signer_backend_t backend;
+    union {
+        struct {
+            unsigned char private_key[32];
+        } local;
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+        struct {
+            nsigner_client_t* client;
+            char role[64];
+            int nostr_index;     /* -1 = not set; when set, overrides role */
+            int has_nostr_index; /* 1 if nostr_index is set */
+        } remote;
+#endif
+    } u;
+};
+
+static int signer_hex_pubkey_to_bytes(const char* hex, unsigned char out[32]) {
+    if (!hex || strlen(hex) != 64 || !out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+    if (nostr_hex_to_bytes(hex, out, 32) != 0) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+    return NOSTR_SUCCESS;
+}
+
+static int signer_local_get_public_key(nostr_signer_t* signer, char out_pubkey_hex[65]) {
+    unsigned char pubkey[32];
+
+    if (!signer || !out_pubkey_hex) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (nostr_ec_public_key_from_private_key(signer->u.local.private_key, pubkey) != 0) {
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    nostr_bytes_to_hex(pubkey, 32, out_pubkey_hex);
+    return NOSTR_SUCCESS;
+}
+
+static int signer_local_sign_event(nostr_signer_t* signer, const cJSON* unsigned_event, cJSON** signed_event_out) {
+    cJSON* pubkey_item;
+    cJSON* created_at_item;
+    cJSON* kind_item;
+    cJSON* tags_item;
+    cJSON* content_item;
+    cJSON* serialize_array;
+    cJSON* signed_event = NULL;
+    char* serialize_string = NULL;
+    unsigned char event_hash[32];
+    unsigned char signature[64];
+    char event_id[65];
+    char sig_hex[129];
+
+    if (!signer || !unsigned_event || !signed_event_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *signed_event_out = NULL;
+
+    pubkey_item = cJSON_GetObjectItem((cJSON*)unsigned_event, "pubkey");
+    created_at_item = cJSON_GetObjectItem((cJSON*)unsigned_event, "created_at");
+    kind_item = cJSON_GetObjectItem((cJSON*)unsigned_event, "kind");
+    tags_item = cJSON_GetObjectItem((cJSON*)unsigned_event, "tags");
+    content_item = cJSON_GetObjectItem((cJSON*)unsigned_event, "content");
+
+    if (!pubkey_item || !created_at_item || !kind_item || !tags_item || !content_item) {
+        return NOSTR_ERROR_EVENT_INVALID_STRUCTURE;
+    }
+
+    serialize_array = cJSON_CreateArray();
+    if (!serialize_array) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    cJSON_AddItemToArray(serialize_array, cJSON_CreateNumber(0));
+    cJSON_AddItemToArray(serialize_array, cJSON_Duplicate(pubkey_item, 1));
+    cJSON_AddItemToArray(serialize_array, cJSON_Duplicate(created_at_item, 1));
+    cJSON_AddItemToArray(serialize_array, cJSON_Duplicate(kind_item, 1));
+    cJSON_AddItemToArray(serialize_array, cJSON_Duplicate(tags_item, 1));
+    cJSON_AddItemToArray(serialize_array, cJSON_Duplicate(content_item, 1));
+
+    serialize_string = cJSON_PrintUnformatted(serialize_array);
+    cJSON_Delete(serialize_array);
+
+    if (!serialize_string) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    if (nostr_sha256((const unsigned char*)serialize_string, strlen(serialize_string), event_hash) != 0) {
+        free(serialize_string);
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    nostr_bytes_to_hex(event_hash, 32, event_id);
+
+    if (nostr_ec_sign(signer->u.local.private_key, event_hash, signature) != 0) {
+        free(serialize_string);
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    nostr_bytes_to_hex(signature, 64, sig_hex);
+
+    signed_event = cJSON_Duplicate((cJSON*)unsigned_event, 1);
+    if (!signed_event) {
+        free(serialize_string);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    cJSON_DeleteItemFromObjectCaseSensitive(signed_event, "id");
+    cJSON_DeleteItemFromObjectCaseSensitive(signed_event, "sig");
+    cJSON_AddStringToObject(signed_event, "id", event_id);
+    cJSON_AddStringToObject(signed_event, "sig", sig_hex);
+
+    *signed_event_out = signed_event;
+    free(serialize_string);
+
+    return NOSTR_SUCCESS;
+}
+
+static int signer_local_nip04_encrypt(nostr_signer_t* signer,
+                                      const char* peer_pubkey_hex,
+                                      const char* plaintext,
+                                      char** ciphertext_out) {
+    unsigned char peer_pubkey[32];
+    char* out;
+    int rc;
+
+    if (!signer || !peer_pubkey_hex || !plaintext || !ciphertext_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *ciphertext_out = NULL;
+
+    rc = signer_hex_pubkey_to_bytes(peer_pubkey_hex, peer_pubkey);
+    if (rc != NOSTR_SUCCESS) {
+        return rc;
+    }
+
+    out = (char*)malloc(NOSTR_NIP04_MAX_ENCRYPTED_SIZE + 1);
+    if (!out) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    rc = nostr_nip04_encrypt(signer->u.local.private_key, peer_pubkey, plaintext, out, NOSTR_NIP04_MAX_ENCRYPTED_SIZE + 1);
+    if (rc != NOSTR_SUCCESS) {
+        free(out);
+        return rc;
+    }
+
+    *ciphertext_out = out;
+    return NOSTR_SUCCESS;
+}
+
+static int signer_local_nip04_decrypt(nostr_signer_t* signer,
+                                      const char* peer_pubkey_hex,
+                                      const char* ciphertext,
+                                      char** plaintext_out) {
+    unsigned char peer_pubkey[32];
+    char* out;
+    int rc;
+
+    if (!signer || !peer_pubkey_hex || !ciphertext || !plaintext_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *plaintext_out = NULL;
+
+    rc = signer_hex_pubkey_to_bytes(peer_pubkey_hex, peer_pubkey);
+    if (rc != NOSTR_SUCCESS) {
+        return rc;
+    }
+
+    out = (char*)malloc(NOSTR_NIP04_MAX_PLAINTEXT_SIZE + 1);
+    if (!out) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    rc = nostr_nip04_decrypt(signer->u.local.private_key, peer_pubkey, ciphertext, out, NOSTR_NIP04_MAX_PLAINTEXT_SIZE + 1);
+    if (rc != NOSTR_SUCCESS) {
+        free(out);
+        return rc;
+    }
+
+    *plaintext_out = out;
+    return NOSTR_SUCCESS;
+}
+
+static int signer_local_nip44_encrypt(nostr_signer_t* signer,
+                                      const char* peer_pubkey_hex,
+                                      const char* plaintext,
+                                      char** ciphertext_out) {
+    unsigned char peer_pubkey[32];
+    char* out;
+    size_t out_size;
+    int rc;
+
+    if (!signer || !peer_pubkey_hex || !plaintext || !ciphertext_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *ciphertext_out = NULL;
+
+    rc = signer_hex_pubkey_to_bytes(peer_pubkey_hex, peer_pubkey);
+    if (rc != NOSTR_SUCCESS) {
+        return rc;
+    }
+
+    out_size = (strlen(plaintext) * 4) + 4096;
+    if (out_size < 8192) {
+        out_size = 8192;
+    }
+
+    out = (char*)malloc(out_size);
+    if (!out) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    rc = nostr_nip44_encrypt(signer->u.local.private_key, peer_pubkey, plaintext, out, out_size);
+    if (rc != NOSTR_SUCCESS) {
+        free(out);
+        return rc;
+    }
+
+    *ciphertext_out = out;
+    return NOSTR_SUCCESS;
+}
+
+static int signer_local_nip44_decrypt(nostr_signer_t* signer,
+                                      const char* peer_pubkey_hex,
+                                      const char* ciphertext,
+                                      char** plaintext_out) {
+    unsigned char peer_pubkey[32];
+    char* out;
+    int rc;
+
+    if (!signer || !peer_pubkey_hex || !ciphertext || !plaintext_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *plaintext_out = NULL;
+
+    rc = signer_hex_pubkey_to_bytes(peer_pubkey_hex, peer_pubkey);
+    if (rc != NOSTR_SUCCESS) {
+        return rc;
+    }
+
+    out = (char*)malloc(NOSTR_NIP44_MAX_PLAINTEXT_SIZE + 1);
+    if (!out) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    rc = nostr_nip44_decrypt(signer->u.local.private_key, peer_pubkey, ciphertext, out, NOSTR_NIP44_MAX_PLAINTEXT_SIZE + 1);
+    if (rc != NOSTR_SUCCESS) {
+        free(out);
+        return rc;
+    }
+
+    *plaintext_out = out;
+    return NOSTR_SUCCESS;
+}
+
+static int signer_local_derive_hmac(nostr_signer_t* signer,
+                                    const char* data,
+                                    char out_digest_hex[65]) {
+    unsigned char mac[32];
+
+    if (!signer || !data || !out_digest_hex) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (nostr_hmac_sha256(signer->u.local.private_key, 32,
+                           (const unsigned char*)data, strlen(data),
+                           mac) != 0) {
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    nostr_bytes_to_hex(mac, 32, out_digest_hex);
+    memset(mac, 0, sizeof(mac));
+    return NOSTR_SUCCESS;
+}
+
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+
+static cJSON* signer_remote_params_with_selector(cJSON* params, const char* role, int has_nostr_index, int nostr_index) {
+    cJSON* selector;
+
+    if (params == NULL) {
+        params = cJSON_CreateArray();
+        if (params == NULL) {
+            return NULL;
+        }
+    }
+
+    /* nostr_index takes precedence over role when set */
+    if (has_nostr_index) {
+        selector = cJSON_CreateObject();
+        if (selector == NULL) {
+            cJSON_Delete(params);
+            return NULL;
+        }
+        cJSON_AddNumberToObject(selector, "nostr_index", nostr_index);
+        cJSON_AddItemToArray(params, selector);
+        return params;
+    }
+
+    if (role == NULL || role[0] == '\0') {
+        return params;
+    }
+
+    selector = cJSON_CreateObject();
+    if (selector == NULL) {
+        cJSON_Delete(params);
+        return NULL;
+    }
+
+    cJSON_AddStringToObject(selector, "role", role);
+    cJSON_AddItemToArray(params, selector);
+    return params;
+}
+
+static int signer_remote_get_public_key(nostr_signer_t* signer, char out_pubkey_hex[65]) {
+    cJSON* params;
+    cJSON* result = NULL;
+    const char* result_str;
+    int rc;
+
+    if (!signer || !out_pubkey_hex) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    params = signer_remote_params_with_selector(NULL, signer->u.remote.role,
+                                                  signer->u.remote.has_nostr_index,
+                                                  signer->u.remote.nostr_index);
+    if (params == NULL) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    rc = nsigner_client_call(signer->u.remote.client, "nostr_get_public_key", params, &result);
+    if (rc != NOSTR_SUCCESS) {
+        return rc;
+    }
+
+    if (!cJSON_IsString(result) || result->valuestring == NULL || strlen(result->valuestring) != 64) {
+        cJSON_Delete(result);
+        return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+    }
+
+    result_str = result->valuestring;
+    memcpy(out_pubkey_hex, result_str, 64);
+    out_pubkey_hex[64] = '\0';
+
+    cJSON_Delete(result);
+    return NOSTR_SUCCESS;
+}
+
+static int signer_remote_sign_event(nostr_signer_t* signer, const cJSON* unsigned_event, cJSON** signed_event_out) {
+    cJSON* params;
+    cJSON* result = NULL;
+    cJSON* parsed = NULL;
+    char* event_json;
+    int rc;
+
+    if (!signer || !unsigned_event || !signed_event_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *signed_event_out = NULL;
+
+    event_json = cJSON_PrintUnformatted((cJSON*)unsigned_event);
+    if (event_json == NULL) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    params = cJSON_CreateArray();
+    if (params == NULL) {
+        free(event_json);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    cJSON_AddItemToArray(params, cJSON_CreateString(event_json));
+    free(event_json);
+
+    params = signer_remote_params_with_selector(params, signer->u.remote.role,
+                                                  signer->u.remote.has_nostr_index,
+                                                  signer->u.remote.nostr_index);
+    if (params == NULL) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    rc = nsigner_client_call(signer->u.remote.client, "nostr_sign_event", params, &result);
+    if (rc != NOSTR_SUCCESS) {
+        return rc;
+    }
+
+    if (cJSON_IsString(result) && result->valuestring != NULL) {
+        parsed = cJSON_Parse(result->valuestring);
+        cJSON_Delete(result);
+        if (parsed == NULL || !cJSON_IsObject(parsed)) {
+            cJSON_Delete(parsed);
+            return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+        }
+        *signed_event_out = parsed;
+        return NOSTR_SUCCESS;
+    }
+
+    if (cJSON_IsObject(result)) {
+        *signed_event_out = cJSON_Duplicate(result, 1);
+        cJSON_Delete(result);
+        if (*signed_event_out == NULL) {
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+        return NOSTR_SUCCESS;
+    }
+
+    cJSON_Delete(result);
+    return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+}
+
+static int signer_remote_encrypt_decrypt(nostr_signer_t* signer,
+                                         const char* method,
+                                         const char* peer_pubkey_hex,
+                                         const char* in,
+                                         char** out) {
+    cJSON* params;
+    cJSON* result = NULL;
+    const char* result_str;
+    int rc;
+
+    if (!signer || !method || !peer_pubkey_hex || !in || !out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *out = NULL;
+
+    params = cJSON_CreateArray();
+    if (params == NULL) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    cJSON_AddItemToArray(params, cJSON_CreateString(peer_pubkey_hex));
+    cJSON_AddItemToArray(params, cJSON_CreateString(in));
+
+    params = signer_remote_params_with_selector(params, signer->u.remote.role,
+                                                  signer->u.remote.has_nostr_index,
+                                                  signer->u.remote.nostr_index);
+    if (params == NULL) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    rc = nsigner_client_call(signer->u.remote.client, method, params, &result);
+    if (rc != NOSTR_SUCCESS) {
+        return rc;
+    }
+
+    if (!cJSON_IsString(result) || result->valuestring == NULL) {
+        cJSON_Delete(result);
+        return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+    }
+
+    result_str = result->valuestring;
+    {
+        size_t n = strlen(result_str);
+        *out = (char*)malloc(n + 1);
+        if (*out == NULL) {
+            cJSON_Delete(result);
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+        memcpy(*out, result_str, n + 1);
+    }
+    cJSON_Delete(result);
+
+    return NOSTR_SUCCESS;
+}
+
+static int signer_remote_nip04_encrypt(nostr_signer_t* signer,
+                                       const char* peer_pubkey_hex,
+                                       const char* plaintext,
+                                       char** ciphertext_out) {
+    return signer_remote_encrypt_decrypt(signer, "nostr_nip04_encrypt", peer_pubkey_hex, plaintext, ciphertext_out);
+}
+
+static int signer_remote_nip04_decrypt(nostr_signer_t* signer,
+                                       const char* peer_pubkey_hex,
+                                       const char* ciphertext,
+                                       char** plaintext_out) {
+    return signer_remote_encrypt_decrypt(signer, "nostr_nip04_decrypt", peer_pubkey_hex, ciphertext, plaintext_out);
+}
+
+static int signer_remote_nip44_encrypt(nostr_signer_t* signer,
+                                       const char* peer_pubkey_hex,
+                                       const char* plaintext,
+                                       char** ciphertext_out) {
+    return signer_remote_encrypt_decrypt(signer, "nostr_nip44_encrypt", peer_pubkey_hex, plaintext, ciphertext_out);
+}
+
+static int signer_remote_nip44_decrypt(nostr_signer_t* signer,
+                                       const char* peer_pubkey_hex,
+                                       const char* ciphertext,
+                                       char** plaintext_out) {
+    return signer_remote_encrypt_decrypt(signer, "nostr_nip44_decrypt", peer_pubkey_hex, ciphertext, plaintext_out);
+}
+
+static int signer_remote_derive_hmac(nostr_signer_t* signer,
+                                     const char* data,
+                                     char out_digest_hex[65]) {
+    cJSON* params;
+    cJSON* opts = NULL;
+    cJSON* result = NULL;
+    cJSON* parsed = NULL;
+    cJSON* digest_item = NULL;
+    const char* digest_str = NULL;
+    int rc;
+
+    if (!signer || !data || !out_digest_hex) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    params = cJSON_CreateArray();
+    if (params == NULL) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    cJSON_AddItemToArray(params, cJSON_CreateString(data));
+
+    /* Build the options object with algorithm:"secp256k1" and the selector
+     * (role or nostr_index). The derive verb requires index, so when
+     * has_nostr_index is set we include it; otherwise we include role (the
+     * nsigner derive handler requires index, so callers using the remote
+     * backend must set nostr_index via nostr_signer_nsigner_set_nostr_index
+     * before calling derive_hmac). */
+    opts = cJSON_CreateObject();
+    if (opts == NULL) {
+        cJSON_Delete(params);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+    cJSON_AddStringToObject(opts, "algorithm", "secp256k1");
+    if (signer->u.remote.has_nostr_index) {
+        cJSON_AddNumberToObject(opts, "index", signer->u.remote.nostr_index);
+    } else if (signer->u.remote.role[0] != '\0') {
+        cJSON_AddStringToObject(opts, "role", signer->u.remote.role);
+    }
+    cJSON_AddItemToArray(params, opts);
+
+    rc = nsigner_client_call(signer->u.remote.client, "derive", params, &result);
+    if (rc != NOSTR_SUCCESS) {
+        return rc;
+    }
+
+    /* result is a JSON string: {"algorithm":"secp256k1","key_id":"...","digest":"<64hex>"} */
+    if (!cJSON_IsString(result) || result->valuestring == NULL) {
+        cJSON_Delete(result);
+        return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+    }
+    parsed = cJSON_Parse(result->valuestring);
+    cJSON_Delete(result);
+    if (parsed == NULL) {
+        return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+    }
+    digest_item = cJSON_GetObjectItemCaseSensitive(parsed, "digest");
+    if (!cJSON_IsString(digest_item) || digest_item->valuestring == NULL ||
+        strlen(digest_item->valuestring) != 64) {
+        cJSON_Delete(parsed);
+        return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+    }
+    digest_str = digest_item->valuestring;
+    memcpy(out_digest_hex, digest_str, 64);
+    out_digest_hex[64] = '\0';
+    cJSON_Delete(parsed);
+    return NOSTR_SUCCESS;
+}
+
+#endif /* NOSTR_ENABLE_NSIGNER_CLIENT */
+
+nostr_signer_t* nostr_signer_local(const unsigned char private_key[32]) {
+    nostr_signer_t* signer;
+
+    if (!private_key) {
+        return NULL;
+    }
+
+    signer = (nostr_signer_t*)calloc(1, sizeof(nostr_signer_t));
+    if (!signer) {
+        return NULL;
+    }
+
+    signer->backend = NOSTR_SIGNER_BACKEND_LOCAL;
+    memcpy(signer->u.local.private_key, private_key, 32);
+    return signer;
+}
+
+void nostr_signer_free(nostr_signer_t* signer) {
+    if (!signer) {
+        return;
+    }
+
+    if (signer->backend == NOSTR_SIGNER_BACKEND_LOCAL) {
+        memset(signer->u.local.private_key, 0, sizeof(signer->u.local.private_key));
+    }
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    else if (signer->backend == NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE) {
+        if (signer->u.remote.client != NULL) {
+            nsigner_client_free(signer->u.remote.client);
+            signer->u.remote.client = NULL;
+        }
+        memset(signer->u.remote.role, 0, sizeof(signer->u.remote.role));
+    }
+#endif
+
+    free(signer);
+}
+
+int nostr_signer_get_public_key(nostr_signer_t* signer, char out_pubkey_hex[65]) {
+    if (!signer || !out_pubkey_hex) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (signer->backend == NOSTR_SIGNER_BACKEND_LOCAL) {
+        return signer_local_get_public_key(signer, out_pubkey_hex);
+    }
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    if (signer->backend == NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE) {
+        return signer_remote_get_public_key(signer, out_pubkey_hex);
+    }
+#endif
+
+    return NOSTR_ERROR_INVALID_INPUT;
+}
+
+int nostr_signer_sign_event(nostr_signer_t* signer, const cJSON* unsigned_event, cJSON** signed_event_out) {
+    if (!signer || !unsigned_event || !signed_event_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (signer->backend == NOSTR_SIGNER_BACKEND_LOCAL) {
+        return signer_local_sign_event(signer, unsigned_event, signed_event_out);
+    }
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    if (signer->backend == NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE) {
+        return signer_remote_sign_event(signer, unsigned_event, signed_event_out);
+    }
+#endif
+
+    return NOSTR_ERROR_INVALID_INPUT;
+}
+
+int nostr_signer_nip04_encrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* plaintext,
+                               char** ciphertext_out) {
+    if (!signer || !peer_pubkey_hex || !plaintext || !ciphertext_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (signer->backend == NOSTR_SIGNER_BACKEND_LOCAL) {
+        return signer_local_nip04_encrypt(signer, peer_pubkey_hex, plaintext, ciphertext_out);
+    }
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    if (signer->backend == NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE) {
+        return signer_remote_nip04_encrypt(signer, peer_pubkey_hex, plaintext, ciphertext_out);
+    }
+#endif
+
+    return NOSTR_ERROR_INVALID_INPUT;
+}
+
+int nostr_signer_nip04_decrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* ciphertext,
+                               char** plaintext_out) {
+    if (!signer || !peer_pubkey_hex || !ciphertext || !plaintext_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (signer->backend == NOSTR_SIGNER_BACKEND_LOCAL) {
+        return signer_local_nip04_decrypt(signer, peer_pubkey_hex, ciphertext, plaintext_out);
+    }
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    if (signer->backend == NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE) {
+        return signer_remote_nip04_decrypt(signer, peer_pubkey_hex, ciphertext, plaintext_out);
+    }
+#endif
+
+    return NOSTR_ERROR_INVALID_INPUT;
+}
+
+int nostr_signer_nip44_encrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* plaintext,
+                               char** ciphertext_out) {
+    if (!signer || !peer_pubkey_hex || !plaintext || !ciphertext_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (signer->backend == NOSTR_SIGNER_BACKEND_LOCAL) {
+        return signer_local_nip44_encrypt(signer, peer_pubkey_hex, plaintext, ciphertext_out);
+    }
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    if (signer->backend == NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE) {
+        return signer_remote_nip44_encrypt(signer, peer_pubkey_hex, plaintext, ciphertext_out);
+    }
+#endif
+
+    return NOSTR_ERROR_INVALID_INPUT;
+}
+
+int nostr_signer_nip44_decrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* ciphertext,
+                               char** plaintext_out) {
+    if (!signer || !peer_pubkey_hex || !ciphertext || !plaintext_out) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (signer->backend == NOSTR_SIGNER_BACKEND_LOCAL) {
+        return signer_local_nip44_decrypt(signer, peer_pubkey_hex, ciphertext, plaintext_out);
+    }
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    if (signer->backend == NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE) {
+        return signer_remote_nip44_decrypt(signer, peer_pubkey_hex, ciphertext, plaintext_out);
+    }
+#endif
+
+    return NOSTR_ERROR_INVALID_INPUT;
+}
+
+int nostr_signer_derive_hmac(nostr_signer_t* signer,
+                             const char* data,
+                             char out_digest_hex[65]) {
+    if (!signer || !data || !out_digest_hex) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (signer->backend == NOSTR_SIGNER_BACKEND_LOCAL) {
+        return signer_local_derive_hmac(signer, data, out_digest_hex);
+    }
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+    if (signer->backend == NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE) {
+        return signer_remote_derive_hmac(signer, data, out_digest_hex);
+    }
+#endif
+
+    return NOSTR_ERROR_INVALID_INPUT;
+}
+
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+static nostr_signer_t* nostr_signer_nsigner_from_transport(nsigner_transport_t* transport, const char* role) {
+    nsigner_client_t* client = NULL;
+    nostr_signer_t* signer = NULL;
+
+    if (transport == NULL) {
+        return NULL;
+    }
+
+    client = nsigner_client_new(transport);
+    if (client == NULL) {
+        return NULL;
+    }
+
+    signer = (nostr_signer_t*)calloc(1, sizeof(*signer));
+    if (signer == NULL) {
+        nsigner_client_free(client);
+        return NULL;
+    }
+
+    signer->backend = NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE;
+    signer->u.remote.client = client;
+    if (role != NULL) {
+        strncpy(signer->u.remote.role, role, sizeof(signer->u.remote.role) - 1);
+        signer->u.remote.role[sizeof(signer->u.remote.role) - 1] = '\0';
+    }
+
+    return signer;
+}
+
+nostr_signer_t* nostr_signer_nsigner_unix(const char* socket_name, const char* role, int timeout_ms) {
+    nsigner_transport_t* transport = NULL;
+    char discovered[8][64];
+    const char* effective_name = socket_name;
+
+    if (effective_name == NULL || effective_name[0] == '\0') {
+        int count = nsigner_transport_list_unix(discovered, 8);
+        if (count != 1) {
+            return NULL;
+        }
+        effective_name = discovered[0];
+    }
+
+    transport = nsigner_transport_open_unix(effective_name, timeout_ms);
+    return nostr_signer_nsigner_from_transport(transport, role);
+}
+
+nostr_signer_t* nostr_signer_nsigner_serial(const char* device_path, const char* role, int timeout_ms) {
+    nsigner_transport_t* transport;
+
+    transport = nsigner_transport_open_serial(device_path, timeout_ms);
+    return nostr_signer_nsigner_from_transport(transport, role);
+}
+
+nostr_signer_t* nostr_signer_nsigner_tcp(const char* host, int port, const char* role, int timeout_ms) {
+    nsigner_transport_t* transport;
+
+    transport = nsigner_transport_open_tcp(host, port, timeout_ms);
+    return nostr_signer_nsigner_from_transport(transport, role);
+}
+
+nostr_signer_t* nostr_signer_nsigner_fds(int read_fd, int write_fd, const char* role, int timeout_ms) {
+    nsigner_transport_t* transport;
+
+    transport = nsigner_transport_open_fds(read_fd, write_fd, timeout_ms);
+    return nostr_signer_nsigner_from_transport(transport, role);
+}
+
+int nostr_signer_nsigner_set_auth(nostr_signer_t* signer,
+                                  const unsigned char auth_privkey[32],
+                                  const char* label) {
+    if (signer == NULL || auth_privkey == NULL) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (signer->backend != NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE || signer->u.remote.client == NULL) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    return nsigner_client_set_auth(signer->u.remote.client, auth_privkey, label);
+}
+
+nostr_signer_t* nostr_signer_nsigner_qrexec(const char* target_qube, const char* service_name, const char* role, int timeout_ms) {
+    nsigner_transport_t* transport;
+
+    transport = nsigner_transport_open_qrexec(target_qube, service_name, timeout_ms);
+    return nostr_signer_nsigner_from_transport(transport, role);
+}
+
+int nostr_signer_nsigner_set_nostr_index(nostr_signer_t* signer, int nostr_index) {
+    if (signer == NULL) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (signer->backend != NOSTR_SIGNER_BACKEND_NSIGNER_REMOTE || signer->u.remote.client == NULL) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (nostr_index < 0) {
+        /* Clear the nostr_index selector, fall back to role */
+        signer->u.remote.has_nostr_index = 0;
+        signer->u.remote.nostr_index = -1;
+    } else {
+        /* Set nostr_index; clear role to avoid ambiguous selector */
+        signer->u.remote.has_nostr_index = 1;
+        signer->u.remote.nostr_index = nostr_index;
+        memset(signer->u.remote.role, 0, sizeof(signer->u.remote.role));
+    }
+
+    return NOSTR_SUCCESS;
+}
+#endif

nostr_core/nostr_signer.h

@@ -0,0 +1,73 @@
+#ifndef NOSTR_SIGNER_H
+#define NOSTR_SIGNER_H
+
+#include <stddef.h>
+#include "nostr_common.h"
+#include "../cjson/cJSON.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct nostr_signer nostr_signer_t;
+
+/* Lifecycle */
+nostr_signer_t* nostr_signer_local(const unsigned char private_key[32]);
+void nostr_signer_free(nostr_signer_t* signer);
+
+/* Core verbs */
+int nostr_signer_get_public_key(nostr_signer_t* signer, char out_pubkey_hex[65]);
+int nostr_signer_sign_event(nostr_signer_t* signer, const cJSON* unsigned_event, cJSON** signed_event_out);
+
+/* Derive a deterministic MAC over caller-supplied data using the signer's
+ * secp256k1 private key: out = HMAC-SHA256(privkey, data).
+ * data is a NUL-terminated UTF-8 string. out_digest_hex receives 64 lowercase
+ * hex chars + NUL. For the local backend this computes directly; for the
+ * nsigner remote backend it calls the "derive" verb (algorithm:"secp256k1").
+ * Returns NOSTR_SUCCESS or an error code. */
+int nostr_signer_derive_hmac(nostr_signer_t* signer,
+                             const char* data,
+                             char out_digest_hex[65]);
+
+/* Encryption verbs (for parity with upcoming remote backends) */
+int nostr_signer_nip04_encrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* plaintext,
+                               char** ciphertext_out);
+int nostr_signer_nip04_decrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* ciphertext,
+                               char** plaintext_out);
+int nostr_signer_nip44_encrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* plaintext,
+                               char** ciphertext_out);
+int nostr_signer_nip44_decrypt(nostr_signer_t* signer,
+                               const char* peer_pubkey_hex,
+                               const char* ciphertext,
+                               char** plaintext_out);
+
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+nostr_signer_t* nostr_signer_nsigner_unix(const char* socket_name, const char* role, int timeout_ms);
+nostr_signer_t* nostr_signer_nsigner_serial(const char* device_path, const char* role, int timeout_ms);
+nostr_signer_t* nostr_signer_nsigner_tcp(const char* host, int port, const char* role, int timeout_ms);
+nostr_signer_t* nostr_signer_nsigner_fds(int read_fd, int write_fd, const char* role, int timeout_ms);
+nostr_signer_t* nostr_signer_nsigner_qrexec(const char* target_qube, const char* service_name, const char* role, int timeout_ms);
+/* TCP mode requires auth envelope per n_signer; set this before making calls. */
+int nostr_signer_nsigner_set_auth(nostr_signer_t* signer,
+                                  const unsigned char auth_privkey[32],
+                                  const char* label);
+/*
+ * Set the nostr_index selector for the remote nsigner backend. When set,
+ * requests use {"nostr_index":N} instead of {"role":"..."}. This is mutually
+ * exclusive with the role parameter (setting index clears role).
+ * Returns NOSTR_SUCCESS or an error code.
+ */
+int nostr_signer_nsigner_set_nostr_index(nostr_signer_t* signer, int nostr_index);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_SIGNER_H */

nostr_core/nsigner_client.c

@@ -0,0 +1,383 @@
+#define _POSIX_C_SOURCE 200112L
+
+#include "nsigner_client.h"
+
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "nip001.h"
+#include "utils.h"
+
+/* Ensure a broken connection returns EPIPE instead of killing the process. */
+static void nsigner_client_ignore_sigpipe_once(void) {
+    static int done = 0;
+    if (!done) {
+        struct sigaction sa;
+        memset(&sa, 0, sizeof(sa));
+        sa.sa_handler = SIG_IGN;
+        (void)sigaction(SIGPIPE, &sa, NULL);
+        done = 1;
+    }
+}
+
+struct nsigner_client {
+    nsigner_transport_t* transport;
+    unsigned long long next_id;
+    int auth_enabled;
+    int connected; /* whether the transport has an open connection ready for a request */
+    unsigned char auth_privkey[32];
+    char auth_label[64];
+    char last_error[256];
+};
+
+static void nsigner_client_set_error(nsigner_client_t* client, const char* msg) {
+    if (client == NULL) {
+        return;
+    }
+    if (msg == NULL) {
+        msg = "unknown";
+    }
+    strncpy(client->last_error, msg, sizeof(client->last_error) - 1);
+    client->last_error[sizeof(client->last_error) - 1] = '\0';
+}
+
+int nsigner_client_compute_body_hash_hex(const cJSON* params, char out_hash_hex[65]) {
+    unsigned char hash[32];
+    char* compact;
+
+    if (out_hash_hex == NULL) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    if (params == NULL) {
+        compact = (char*)malloc(5);
+        if (compact == NULL) {
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+        memcpy(compact, "null", 5);
+    } else {
+        compact = cJSON_PrintUnformatted((cJSON*)params);
+        if (compact == NULL) {
+            return NOSTR_ERROR_MEMORY_FAILED;
+        }
+    }
+
+    if (nostr_sha256((const unsigned char*)compact, strlen(compact), hash) != 0) {
+        free(compact);
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    nostr_bytes_to_hex(hash, sizeof(hash), out_hash_hex);
+    out_hash_hex[64] = '\0';
+    free(compact);
+    return NOSTR_SUCCESS;
+}
+
+static cJSON* nsigner_client_make_tag_pair(const char* key, const char* value) {
+    cJSON* pair;
+
+    if (key == NULL || value == NULL) {
+        return NULL;
+    }
+
+    pair = cJSON_CreateArray();
+    if (pair == NULL) {
+        return NULL;
+    }
+
+    cJSON_AddItemToArray(pair, cJSON_CreateString(key));
+    cJSON_AddItemToArray(pair, cJSON_CreateString(value));
+    return pair;
+}
+
+static int nsigner_client_build_auth(nsigner_client_t* client,
+                                     const char* request_id,
+                                     const char* method,
+                                     const cJSON* params,
+                                     cJSON** out_auth) {
+    cJSON* tags = NULL;
+    cJSON* auth = NULL;
+    char hash_hex[65];
+
+    if (client == NULL || request_id == NULL || method == NULL || out_auth == NULL) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *out_auth = NULL;
+
+    if (nsigner_client_compute_body_hash_hex(params, hash_hex) != NOSTR_SUCCESS) {
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    tags = cJSON_CreateArray();
+    if (tags == NULL) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    cJSON_AddItemToArray(tags, nsigner_client_make_tag_pair("nsigner_rpc", request_id));
+    cJSON_AddItemToArray(tags, nsigner_client_make_tag_pair("nsigner_method", method));
+    cJSON_AddItemToArray(tags, nsigner_client_make_tag_pair("nsigner_body_hash", hash_hex));
+
+    auth = nostr_create_and_sign_event(27235,
+                                       client->auth_label,
+                                       tags,
+                                       client->auth_privkey,
+                                       time(NULL));
+    if (auth == NULL) {
+        cJSON_Delete(tags);
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+
+    *out_auth = auth;
+    return NOSTR_SUCCESS;
+}
+
+static int nsigner_client_next_id(nsigner_client_t* client, char out_id[32]) {
+    if (client == NULL || out_id == NULL) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    snprintf(out_id, 32, "%llu", client->next_id);
+    client->next_id++;
+    return NOSTR_SUCCESS;
+}
+
+static int nsigner_client_map_rpc_error(int rpc_code, const char* rpc_message) {
+    if (rpc_code == 2010 || rpc_code == 2011 || rpc_code == 2012 || rpc_code == 2013 ||
+        rpc_code == 2014 || rpc_code == 2015 || rpc_code == 2016 || rpc_code == 2017) {
+        return NOSTR_ERROR_NIP46_AUTH_CHALLENGE;
+    }
+
+    if (rpc_message != NULL) {
+        if (strcmp(rpc_message, "approval_denied") == 0 || strcmp(rpc_message, "unauthorized") == 0) {
+            return NOSTR_ERROR_AUTH_RULES_DENIED;
+        }
+        if (strcmp(rpc_message, "method_not_found") == 0) {
+            return NOSTR_ERROR_NIP46_UNKNOWN_METHOD;
+        }
+        if (strcmp(rpc_message, "invalid_request") == 0) {
+            return NOSTR_ERROR_NIP46_INVALID_REQUEST;
+        }
+        if (strcmp(rpc_message, "ambiguous_role_selector") == 0 || strcmp(rpc_message, "unknown_role") == 0) {
+            return NOSTR_ERROR_INVALID_INPUT;
+        }
+    }
+
+    if (rpc_code >= 1000 && rpc_code < 2000) {
+        return NOSTR_ERROR_NIP46_INVALID_REQUEST;
+    }
+    return NOSTR_ERROR_NETWORK_FAILED;
+}
+
+nsigner_client_t* nsigner_client_new(nsigner_transport_t* transport) {
+    nsigner_client_t* client;
+
+    if (transport == NULL) {
+        return NULL;
+    }
+
+    client = (nsigner_client_t*)calloc(1, sizeof(*client));
+    if (client == NULL) {
+        transport->close(transport);
+        return NULL;
+    }
+
+    client->transport = transport;
+    client->next_id = 1;
+    client->connected = 1; /* transport was opened connected by its constructor */
+    nsigner_client_set_error(client, "ok");
+    return client;
+}
+
+void nsigner_client_free(nsigner_client_t* client) {
+    if (client == NULL) {
+        return;
+    }
+
+    if (client->transport != NULL) {
+        client->transport->close(client->transport);
+        client->transport = NULL;
+    }
+
+    memset(client->auth_privkey, 0, sizeof(client->auth_privkey));
+    memset(client->auth_label, 0, sizeof(client->auth_label));
+    free(client);
+}
+
+int nsigner_client_set_auth(nsigner_client_t* client, const unsigned char privkey[32], const char* label) {
+    if (client == NULL || privkey == NULL) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    memcpy(client->auth_privkey, privkey, 32);
+    client->auth_enabled = 1;
+
+    if (label == NULL) {
+        label = "";
+    }
+
+    strncpy(client->auth_label, label, sizeof(client->auth_label) - 1);
+    client->auth_label[sizeof(client->auth_label) - 1] = '\0';
+    return NOSTR_SUCCESS;
+}
+
+int nsigner_client_call(nsigner_client_t* client,
+                        const char* method,
+                        cJSON* params,
+                        cJSON** out_result) {
+    cJSON* req = NULL;
+    cJSON* res = NULL;
+    cJSON* result_item;
+    cJSON* error_item;
+    cJSON* code_item;
+    cJSON* message_item;
+    cJSON* params_item;
+    cJSON* auth = NULL;
+    char id_buf[32];
+    char* req_json = NULL;
+    char* res_json = NULL;
+    size_t res_len = 0;
+    int rc;
+
+    if (client == NULL || method == NULL || out_result == NULL || client->transport == NULL) {
+        cJSON_Delete(params);
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+
+    *out_result = NULL;
+
+    nsigner_client_ignore_sigpipe_once();
+
+    /*
+     * The n_signer server closes the connection after handling a single framed
+     * request (one-request-per-connection model). Reconnect before every call
+     * except the first (the transport was opened connected by the constructor).
+     * Transports that do not support reconnection (fd-pair) skip this.
+     */
+    if (client->connected && client->transport->reconnect != NULL) {
+        if (client->transport->reconnect(client->transport) != 0) {
+            nsigner_client_set_error(client, "transport reconnect failed");
+            cJSON_Delete(params);
+            return NOSTR_ERROR_IO_FAILED;
+        }
+    }
+    client->connected = 1;
+
+    rc = nsigner_client_next_id(client, id_buf);
+    if (rc != NOSTR_SUCCESS) {
+        cJSON_Delete(params);
+        return rc;
+    }
+
+    req = cJSON_CreateObject();
+    if (req == NULL) {
+        cJSON_Delete(params);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    cJSON_AddStringToObject(req, "id", id_buf);
+    cJSON_AddStringToObject(req, "method", method);
+
+    if (params == NULL) {
+        params_item = cJSON_CreateNull();
+    } else {
+        params_item = params;
+        params = NULL;
+    }
+
+    if (params_item == NULL) {
+        cJSON_Delete(req);
+        cJSON_Delete(params);
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    cJSON_AddItemToObject(req, "params", params_item);
+
+    if (client->auth_enabled) {
+        rc = nsigner_client_build_auth(client, id_buf, method, params_item, &auth);
+        if (rc != NOSTR_SUCCESS) {
+            nsigner_client_set_error(client, "failed to build auth envelope");
+            cJSON_Delete(req);
+            return rc;
+        }
+        cJSON_AddItemToObject(req, "auth", auth);
+        auth = NULL;
+    }
+
+    req_json = cJSON_PrintUnformatted(req);
+    cJSON_Delete(req);
+    if (req_json == NULL) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    rc = client->transport->send_framed(client->transport, req_json, strlen(req_json));
+    free(req_json);
+    if (rc != 0) {
+        nsigner_client_set_error(client, "transport send failed");
+        return NOSTR_ERROR_IO_FAILED;
+    }
+
+    rc = client->transport->recv_framed(client->transport, &res_json, &res_len);
+    if (rc != 0 || res_json == NULL || res_len == 0) {
+        free(res_json);
+        nsigner_client_set_error(client, "transport receive failed");
+        return NOSTR_ERROR_IO_FAILED;
+    }
+
+    res = cJSON_Parse(res_json);
+    free(res_json);
+    if (res == NULL) {
+        nsigner_client_set_error(client, "invalid JSON response");
+        return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+    }
+
+    error_item = cJSON_GetObjectItemCaseSensitive(res, "error");
+    if (cJSON_IsObject(error_item)) {
+        int rpc_code = 0;
+        const char* rpc_msg = "rpc_error";
+
+        code_item = cJSON_GetObjectItemCaseSensitive(error_item, "code");
+        message_item = cJSON_GetObjectItemCaseSensitive(error_item, "message");
+        if (cJSON_IsNumber(code_item)) {
+            rpc_code = code_item->valueint;
+        }
+        if (cJSON_IsString(message_item) && message_item->valuestring != NULL) {
+            rpc_msg = message_item->valuestring;
+        }
+
+        nsigner_client_set_error(client, rpc_msg);
+        cJSON_Delete(res);
+        return nsigner_client_map_rpc_error(rpc_code, rpc_msg);
+    }
+
+    result_item = cJSON_GetObjectItemCaseSensitive(res, "result");
+    if (result_item == NULL) {
+        nsigner_client_set_error(client, "missing result field");
+        cJSON_Delete(res);
+        return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+    }
+
+    *out_result = cJSON_Duplicate(result_item, 1);
+    cJSON_Delete(res);
+
+    if (*out_result == NULL) {
+        return NOSTR_ERROR_MEMORY_FAILED;
+    }
+
+    nsigner_client_set_error(client, "ok");
+    return NOSTR_SUCCESS;
+}
+
+const char* nsigner_client_last_error(const nsigner_client_t* client) {
+    if (client == NULL) {
+        return "invalid_client";
+    }
+    return client->last_error;
+}
+
+#endif /* NOSTR_ENABLE_NSIGNER_CLIENT */

nostr_core/nsigner_client.h

@@ -0,0 +1,44 @@
+#ifndef NSIGNER_CLIENT_H
+#define NSIGNER_CLIENT_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "nostr_common.h"
+#include "nsigner_transport.h"
+#include "../cjson/cJSON.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+
+typedef struct nsigner_client nsigner_client_t;
+
+nsigner_client_t* nsigner_client_new(nsigner_transport_t* transport); /* takes ownership of transport */
+void nsigner_client_free(nsigner_client_t* client);
+
+int nsigner_client_set_auth(nsigner_client_t* client, const unsigned char privkey[32], const char* label);
+
+/*
+ * low-level: build request JSON, attach auth envelope if enabled, send, recv, parse result/error
+ * params may be NULL and ownership is transferred to the call.
+ */
+int nsigner_client_call(nsigner_client_t* client,
+                        const char* method,
+                        cJSON* params,
+                        cJSON** out_result);
+
+const char* nsigner_client_last_error(const nsigner_client_t* client);
+
+/* Exposed for offline tests and parity checks with n_signer hashing behavior. */
+int nsigner_client_compute_body_hash_hex(const cJSON* params, char out_hash_hex[65]);
+
+#endif /* NOSTR_ENABLE_NSIGNER_CLIENT */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NSIGNER_CLIENT_H */

nostr_core/nsigner_transport.h

@@ -0,0 +1,69 @@
+#ifndef NSIGNER_TRANSPORT_H
+#define NSIGNER_TRANSPORT_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if defined(NOSTR_ENABLE_NSIGNER_CLIENT)
+
+typedef struct nsigner_transport nsigner_transport_t;
+
+struct nsigner_transport {
+    int (*send_framed)(nsigner_transport_t* t, const char* json, size_t len);
+    int (*recv_framed)(nsigner_transport_t* t, char** out_json, size_t* out_len); /* caller frees *out_json */
+    /*
+     * Re-establish the underlying connection. The n_signer server closes the
+     * connection after handling a single framed request, so the client must
+     * reconnect before each call. Returns 0 on success, non-zero on failure.
+     * May be NULL for transports that do not support reconnection (e.g. fd-pair);
+     * callers should treat a NULL reconnect as "not supported".
+     */
+    int (*reconnect)(nsigner_transport_t* t);
+    void (*close)(nsigner_transport_t* t);
+    void* ctx;
+};
+
+/* Raw framed I/O helpers for existing connected file descriptors. */
+int nsigner_transport_send_framed_fd(int fd, const char* json, size_t len);
+int nsigner_transport_recv_framed_fd(int fd, char** out_json, size_t* out_len);
+
+/* UNIX abstract socket transport (socket_name without leading '@'). */
+nsigner_transport_t* nsigner_transport_open_unix(const char* socket_name, int timeout_ms);
+
+/* TCP transport (host + port), with IPv4/IPv6 resolution via getaddrinfo. */
+nsigner_transport_t* nsigner_transport_open_tcp(const char* host, int port, int timeout_ms);
+
+/* USB CDC-ACM serial transport (device path like /dev/ttyACM0). */
+nsigner_transport_t* nsigner_transport_open_serial(const char* device_path, int timeout_ms);
+
+/*
+ * Framed transport over existing file descriptors (read_fd, write_fd).
+ * close() closes both owned fds. If passing STDIN_FILENO/STDOUT_FILENO and you do not
+ * want them closed, pass dup()'d descriptors instead.
+ */
+nsigner_transport_t* nsigner_transport_open_fds(int read_fd, int write_fd, int timeout_ms);
+
+/*
+ * Qubes qrexec transport: spawns `qrexec-client-vm <target_qube> <service_name>`
+ * as a subprocess and pipes framed I/O through its stdin/stdout. Each reconnect
+ * re-spawns the subprocess (qrexec handles one request per invocation).
+ * Only works on Qubes OS AppVMs; on other hosts the exec will fail.
+ */
+nsigner_transport_t* nsigner_transport_open_qrexec(const char* target_qube, const char* service_name, int timeout_ms);
+
+/* Enumerate /proc/net/unix abstract sockets beginning with @nsigner, returns count copied. */
+int nsigner_transport_list_unix(char names[][64], int max_names);
+
+/* Best-effort enumerate serial devices (e.g. /dev/ttyACM*), returns count copied. */
+int nsigner_transport_list_serial(char paths[][64], int max_paths);
+
+#endif /* NOSTR_ENABLE_NSIGNER_CLIENT */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NSIGNER_TRANSPORT_H */

nostr_core/request_validator.h

@@ -0,0 +1,274 @@
+/*
+ * NOSTR Core Library - Request Validator
+ * 
+ * Unified authentication and authorization system for NOSTR applications.
+ * Provides rule-based validation for requests with pluggable database backends.
+ * 
+ * This module combines basic NOSTR event validation with sophisticated 
+ * authentication rules to provide a single entry point for request validation
+ * across different NOSTR applications (ginxsom, c-relay, etc.).
+ */
+
+#ifndef NOSTR_REQUEST_VALIDATOR_H
+#define NOSTR_REQUEST_VALIDATOR_H
+
+#include "nostr_common.h"
+#include <time.h>
+#include <sqlite3.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Forward declaration for cJSON
+struct cJSON;
+
+// Authentication rule types
+typedef enum {
+    NOSTR_AUTH_RULE_PUBKEY_WHITELIST,
+    NOSTR_AUTH_RULE_PUBKEY_BLACKLIST,
+    NOSTR_AUTH_RULE_HASH_BLACKLIST,
+    NOSTR_AUTH_RULE_MIME_WHITELIST,
+    NOSTR_AUTH_RULE_MIME_BLACKLIST,
+    NOSTR_AUTH_RULE_SIZE_LIMIT,
+    NOSTR_AUTH_RULE_RATE_LIMIT,
+    NOSTR_AUTH_RULE_CUSTOM
+} nostr_auth_rule_type_t;
+
+// Authentication request context
+typedef struct {
+    const char* operation;        // Operation type ("upload", "delete", "list", "publish")
+    const char* auth_header;      // Raw authorization header (optional)
+    struct cJSON* event;          // NOSTR event for validation (optional)
+    
+    // Resource context (for file/blob operations)
+    const char* resource_hash;    // Resource hash (SHA-256, optional)
+    const char* mime_type;        // MIME type (optional)
+    long file_size;               // File size (optional)
+    
+    // Client context
+    const char* client_ip;        // Client IP for rate limiting (optional)
+    void* app_context;            // Application-specific context (optional)
+} nostr_request_t;
+
+// Authentication result
+typedef struct {
+    int valid;                    // 0 = invalid/denied, 1 = valid/allowed
+    int error_code;               // NOSTR_SUCCESS or specific error code
+    char reason[256];             // Human-readable reason for denial
+    char pubkey[65];              // Extracted pubkey from validated event (if available)
+    int rule_id;                  // Rule ID that made the decision (0 if no rule)
+    int priority;                 // Priority of the rule that matched
+    time_t cached_until;          // Cache expiration time
+} nostr_request_result_t;
+
+// Authentication rule definition
+typedef struct {
+    int rule_id;                  // Unique rule identifier
+    nostr_auth_rule_type_t type;  // Rule type
+    char operation[32];           // Target operation ("*", "upload", "delete", "publish", etc.)
+    char target[256];             // Rule target (pubkey, hash, mime pattern, etc.)
+    char value[256];              // Rule value (size limit, rate limit, custom data)
+    int priority;                 // Rule priority (lower number = higher priority)
+    int enabled;                  // 1 = enabled, 0 = disabled
+    time_t expires_at;            // Expiration timestamp (0 = never expires)
+    char description[512];        // Human-readable description
+    time_t created_at;            // Creation timestamp
+} nostr_auth_rule_t;
+
+// Database backend interface (pluggable)
+typedef struct nostr_auth_db_interface {
+    const char* name;             // Backend name ("sqlite", "redis", etc.)
+    
+    // Database lifecycle
+    int (*init)(const char* db_path, const char* app_name);
+    void (*cleanup)(void);
+    
+    // Configuration management
+    int (*get_config)(const char* key, char* value, size_t value_size);
+    int (*set_config)(const char* key, const char* value);
+    
+    // Rule querying and management
+    int (*query_rules)(const nostr_request_t* request, nostr_auth_rule_t** rules, int* count);
+    int (*rule_add)(const nostr_auth_rule_t* rule);
+    int (*rule_remove)(int rule_id);
+    int (*rule_update)(const nostr_auth_rule_t* rule);
+    int (*rule_list)(const char* operation, nostr_auth_rule_t** rules, int* count);
+    
+    // Caching operations
+    int (*cache_get)(const char* cache_key, nostr_request_result_t* result);
+    int (*cache_set)(const char* cache_key, const nostr_request_result_t* result, int ttl);
+    int (*cache_clear)(void);
+} nostr_auth_db_interface_t;
+
+//=============================================================================
+// CORE API FUNCTIONS
+//=============================================================================
+
+/**
+ * Initialize the request validator system with application database
+ * 
+ * @param app_db_path Path to application's SQLite database
+ * @param app_name Application name for logging/identification
+ * @return NOSTR_SUCCESS on success, error code on failure
+ */
+int nostr_request_validator_init(const char* app_db_path, const char* app_name);
+
+/**
+ * Initialize with shared database (future use)
+ * 
+ * @param shared_db_path Path to shared authentication database
+ * @param app_name Application name for logging/identification
+ * @return NOSTR_SUCCESS on success, error code on failure
+ */
+int nostr_request_validator_init_shared(const char* shared_db_path, const char* app_name);
+
+/**
+ * Main request validation function - validates both NOSTR events and authentication rules
+ * 
+ * @param request Request context with operation, auth header, and resource details
+ * @param result Result structure with validation outcome and details
+ * @return NOSTR_SUCCESS on successful validation processing, error code on system failure
+ */
+int nostr_validate_request(const nostr_request_t* request, nostr_request_result_t* result);
+
+/**
+ * Check if authentication rules system is enabled
+ * 
+ * @return 1 if enabled, 0 if disabled
+ */
+int nostr_auth_rules_enabled(void);
+
+/**
+ * Cleanup request validator resources
+ */
+void nostr_request_validator_cleanup(void);
+
+//=============================================================================
+// CONVENIENCE FUNCTIONS
+//=============================================================================
+
+/**
+ * Convenience function for upload validation (ginxsom integration)
+ * 
+ * @param pubkey Uploader public key (optional, extracted from auth if NULL)
+ * @param auth_header Authorization header with NOSTR event
+ * @param hash File hash (SHA-256)
+ * @param mime_type File MIME type
+ * @param file_size File size in bytes
+ * @return NOSTR_SUCCESS if allowed, error code if denied
+ */
+int nostr_auth_check_upload(const char* pubkey, const char* auth_header, 
+                           const char* hash, const char* mime_type, long file_size);
+
+/**
+ * Convenience function for delete validation (ginxsom integration)
+ * 
+ * @param pubkey Requester public key
+ * @param auth_header Authorization header with NOSTR event
+ * @param hash File hash to delete
+ * @return NOSTR_SUCCESS if allowed, error code if denied
+ */
+int nostr_auth_check_delete(const char* pubkey, const char* auth_header, const char* hash);
+
+/**
+ * Convenience function for publish validation (c-relay integration)
+ * 
+ * @param pubkey Publisher public key
+ * @param event NOSTR event to publish
+ * @return NOSTR_SUCCESS if allowed, error code if denied
+ */
+int nostr_auth_check_publish(const char* pubkey, struct cJSON* event);
+
+//=============================================================================
+// RULE MANAGEMENT FUNCTIONS
+//=============================================================================
+
+/**
+ * Add a new authentication rule
+ * 
+ * @param rule Rule definition to add
+ * @return NOSTR_SUCCESS on success, error code on failure
+ */
+int nostr_auth_rule_add(const nostr_auth_rule_t* rule);
+
+/**
+ * Remove an authentication rule by ID
+ * 
+ * @param rule_id Rule ID to remove
+ * @return NOSTR_SUCCESS on success, error code on failure
+ */
+int nostr_auth_rule_remove(int rule_id);
+
+/**
+ * Update an existing authentication rule
+ * 
+ * @param rule Updated rule definition
+ * @return NOSTR_SUCCESS on success, error code on failure
+ */
+int nostr_auth_rule_update(const nostr_auth_rule_t* rule);
+
+/**
+ * List authentication rules for a specific operation
+ * 
+ * @param operation Target operation ("*" for all operations)
+ * @param rules Pointer to receive allocated array of rules
+ * @param count Pointer to receive number of rules returned
+ * @return NOSTR_SUCCESS on success, error code on failure
+ */
+int nostr_auth_rule_list(const char* operation, nostr_auth_rule_t** rules, int* count);
+
+/**
+ * Free rule array allocated by nostr_auth_rule_list
+ * 
+ * @param rules Rule array to free
+ * @param count Number of rules in array
+ */
+void nostr_auth_rules_free(nostr_auth_rule_t* rules, int count);
+
+//=============================================================================
+// DATABASE BACKEND MANAGEMENT
+//=============================================================================
+
+/**
+ * Register a database backend implementation
+ * 
+ * @param backend Backend interface implementation
+ * @return NOSTR_SUCCESS on success, error code on failure
+ */
+int nostr_auth_register_db_backend(const nostr_auth_db_interface_t* backend);
+
+/**
+ * Set active database backend by name
+ * 
+ * @param backend_name Name of backend to activate
+ * @return NOSTR_SUCCESS on success, error code on failure
+ */
+int nostr_auth_set_db_backend(const char* backend_name);
+
+//=============================================================================
+// CACHE MANAGEMENT
+//=============================================================================
+
+/**
+ * Clear authentication decision cache
+ * 
+ * @return NOSTR_SUCCESS on success, error code on failure
+ */
+int nostr_auth_cache_clear(void);
+
+/**
+ * Get cache statistics
+ * 
+ * @param hit_count Pointer to receive cache hit count
+ * @param miss_count Pointer to receive cache miss count
+ * @param entries Pointer to receive current number of cache entries
+ * @return NOSTR_SUCCESS on success, error code on failure
+ */
+int nostr_auth_cache_stats(int* hit_count, int* miss_count, int* entries);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NOSTR_REQUEST_VALIDATOR_H */

nostr_core/utils.c

@@ -9,14 +9,28 @@
 #include <stdlib.h>
 #include <string.h>
 
-// Include our secp256k1 wrapper for elliptic curve operations
-#include "crypto/nostr_secp256k1.h"
+// Forward declarations for crypto functions (private API)
+// These functions are implemented in crypto/ but not exposed through public headers
 
-// Include our self-contained AES implementation for NIP-04
-#include "crypto/nostr_aes.h"
+// secp256k1 functions
+typedef struct {
+    unsigned char data[64];
+} nostr_secp256k1_pubkey;
 
-// Include our ChaCha20 implementation for NIP-44
-#include "crypto/nostr_chacha20.h"
+typedef struct {
+    unsigned char data[96];
+} nostr_secp256k1_keypair;
+
+int nostr_secp256k1_context_create(void);
+void nostr_secp256k1_context_destroy(void);
+int nostr_secp256k1_ec_pubkey_parse(nostr_secp256k1_pubkey* pubkey, const unsigned char* input, size_t inputlen);
+int nostr_secp256k1_ecdh(unsigned char* output, const nostr_secp256k1_pubkey* pubkey, const unsigned char* privkey, void* hashfp, void* data);
+int nostr_secp256k1_ec_seckey_verify(const unsigned char* seckey);
+int nostr_secp256k1_ec_pubkey_create(nostr_secp256k1_pubkey* pubkey, const unsigned char* privkey);
+int nostr_secp256k1_ec_pubkey_serialize_compressed(unsigned char* output, const nostr_secp256k1_pubkey* pubkey);
+int nostr_secp256k1_keypair_create(nostr_secp256k1_keypair* keypair, const unsigned char* privkey);
+int nostr_secp256k1_schnorrsig_sign32(unsigned char* sig, const unsigned char* msg32, const nostr_secp256k1_keypair* keypair, const unsigned char* aux_rand32);
+int nostr_secp256k1_ec_seckey_tweak_add(unsigned char* seckey, const unsigned char* tweak);
 
 
 // =============================================================================
@@ -328,6 +342,131 @@ int nostr_sha256(const unsigned char* data, size_t len, unsigned char* hash) {
     return 0;
 }
 
+// =============================================================================
+// STREAMING SHA-256 IMPLEMENTATION
+// =============================================================================
+
+int nostr_sha256_init(nostr_sha256_ctx_t* ctx) {
+    if (!ctx) return -1;
+    
+    // Initialize SHA-256 state
+    ctx->state[0] = 0x6a09e667;
+    ctx->state[1] = 0xbb67ae85;
+    ctx->state[2] = 0x3c6ef372;
+    ctx->state[3] = 0xa54ff53a;
+    ctx->state[4] = 0x510e527f;
+    ctx->state[5] = 0x9b05688c;
+    ctx->state[6] = 0x1f83d9ab;
+    ctx->state[7] = 0x5be0cd19;
+    
+    // Initialize counters and buffer
+    ctx->bitlen = 0;
+    ctx->buflen = 0;
+    
+    return 0;
+}
+
+int nostr_sha256_update(nostr_sha256_ctx_t* ctx, const unsigned char* data, size_t len) {
+    if (!ctx || !data) return -1;
+    
+    for (size_t i = 0; i < len; i++) {
+        ctx->buffer[ctx->buflen] = data[i];
+        ctx->buflen++;
+        
+        // Process complete blocks
+        if (ctx->buflen == 64) {
+            sha256_transform(ctx->state, ctx->buffer);
+            ctx->bitlen += 512; // 64 bytes * 8 bits
+            ctx->buflen = 0;
+        }
+    }
+    
+    return 0;
+}
+
+int nostr_sha256_final(nostr_sha256_ctx_t* ctx, unsigned char* hash) {
+    if (!ctx || !hash) return -1;
+    
+    // Calculate final bit length
+    uint64_t final_bitlen = ctx->bitlen + (ctx->buflen * 8);
+    
+    // Pad the message
+    ctx->buffer[ctx->buflen] = 0x80;
+    ctx->buflen++;
+    
+    // If not enough space for length, pad and process another block
+    if (ctx->buflen > 56) {
+        while (ctx->buflen < 64) {
+            ctx->buffer[ctx->buflen] = 0x00;
+            ctx->buflen++;
+        }
+        sha256_transform(ctx->state, ctx->buffer);
+        ctx->buflen = 0;
+    }
+    
+    // Pad with zeros up to 56 bytes
+    while (ctx->buflen < 56) {
+        ctx->buffer[ctx->buflen] = 0x00;
+        ctx->buflen++;
+    }
+    
+    // Append length as big-endian 64-bit integer
+    for (int i = 0; i < 8; i++) {
+        ctx->buffer[56 + i] = (final_bitlen >> (56 - i * 8)) & 0xff;
+    }
+    
+    // Process final block
+    sha256_transform(ctx->state, ctx->buffer);
+    
+    // Convert state to output bytes
+    for (int i = 0; i < 8; i++) {
+        hash[i * 4] = (ctx->state[i] >> 24) & 0xff;
+        hash[i * 4 + 1] = (ctx->state[i] >> 16) & 0xff;
+        hash[i * 4 + 2] = (ctx->state[i] >> 8) & 0xff;
+        hash[i * 4 + 3] = ctx->state[i] & 0xff;
+    }
+    
+    // Clear sensitive data
+    memory_clear(ctx, sizeof(nostr_sha256_ctx_t));
+    
+    return 0;
+}
+
+int nostr_sha256_file_stream(const char* filename, unsigned char* hash) {
+#ifndef NOSTR_NO_FILESYSTEM
+    if (!filename || !hash) return -1;
+
+    FILE* file = fopen(filename, "rb");
+    if (!file) return -1;
+
+    nostr_sha256_ctx_t ctx;
+    if (nostr_sha256_init(&ctx) != 0) {
+        fclose(file);
+        return -1;
+    }
+
+    // Process file in 4KB chunks for memory efficiency
+    unsigned char buffer[4096];
+    size_t bytes_read;
+
+    while ((bytes_read = fread(buffer, 1, sizeof(buffer), file)) > 0) {
+        if (nostr_sha256_update(&ctx, buffer, bytes_read) != 0) {
+            fclose(file);
+            return -1;
+        }
+    }
+
+    fclose(file);
+
+    // Finalize and return result
+    return nostr_sha256_final(&ctx, hash);
+#else
+    (void)filename;
+    (void)hash;
+    return -1;
+#endif
+}
+
 // =============================================================================
 // HMAC IMPLEMENTATION
 // =============================================================================
@@ -1192,6 +1331,11 @@ static int find_word_index(const char* word) {
     return -1;
 }
 
+const char * const *nostr_bip39_get_wordlist(int *count) {
+    if (count) *count = 2048;
+    return BIP39_WORDLIST;
+}
+
 int nostr_bip39_mnemonic_from_bytes(const unsigned char* entropy, size_t entropy_len,
                                    char* mnemonic) {
     if (!entropy || !mnemonic || entropy_len < 16 || entropy_len > 32) return -1;

nostr_core/utils.h

@@ -24,6 +24,11 @@ void nostr_bytes_to_hex(const unsigned char *bytes, size_t len, char *hex);
 // Convert hexadecimal string to bytes
 int nostr_hex_to_bytes(const char *hex, unsigned char *bytes, size_t len);
 
+// Get the BIP-39 English wordlist (2048 words). Returns a pointer to a
+// static array; count is set to 2048 if non-NULL. The pointer is valid
+// for the lifetime of the process.
+const char * const *nostr_bip39_get_wordlist(int *count);
+
 // Base64 encoding function 
 size_t base64_encode(const unsigned char *data, size_t len, char *output,
                      size_t output_size);
@@ -45,6 +50,30 @@ void nostr_crypto_cleanup(void);
 // SHA-256 hash function
 int nostr_sha256(const unsigned char *data, size_t len, unsigned char *hash);
 
+// =============================================================================
+// STREAMING SHA-256 FUNCTIONS
+// =============================================================================
+
+// SHA-256 streaming context
+typedef struct {
+    uint32_t state[8];      // Current hash state
+    unsigned char buffer[64]; // Input buffer for incomplete blocks
+    uint64_t bitlen;        // Total bits processed
+    size_t buflen;          // Current buffer length
+} nostr_sha256_ctx_t;
+
+// Initialize SHA-256 streaming context
+int nostr_sha256_init(nostr_sha256_ctx_t* ctx);
+
+// Update SHA-256 context with new data
+int nostr_sha256_update(nostr_sha256_ctx_t* ctx, const unsigned char* data, size_t len);
+
+// Finalize SHA-256 and output hash
+int nostr_sha256_final(nostr_sha256_ctx_t* ctx, unsigned char* hash);
+
+// Stream SHA-256 hash of a file
+int nostr_sha256_file_stream(const char* filename, unsigned char* hash);
+
 // HMAC-SHA256
 int nostr_hmac_sha256(const unsigned char *key, size_t key_len,
                       const unsigned char *data, size_t data_len,

nostr_core_lib.code-workspace

@@ -0,0 +1,10 @@
+{
+	"folders": [
+		{
+			"path": "."
+		}
+	],
+	"settings": {
+		"git.ignoreLimitWarning": true
+	}
+}

nostr_websocket/nostr_websocket_openssl.c

@@ -1,5 +1,6 @@
 #define _GNU_SOURCE
 #include "nostr_websocket_tls.h"
+#include "../nostr_core/nostr_log.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -11,6 +12,18 @@
 #include <errno.h>
 #include <time.h>
 #include <sys/select.h>
+#include <fcntl.h>
+
+static int ws_connect_debug_enabled(void) {
+    static int initialized = 0;
+    static int enabled = 0;
+    if (!initialized) {
+        const char* env = getenv("NOSTR_WS_CONNECT_DEBUG");
+        enabled = (env && env[0] != '\0' && strcmp(env, "0") != 0);
+        initialized = 1;
+    }
+    return enabled;
+}
 
 // OpenSSL headers
 #include <openssl/ssl.h>
@@ -22,15 +35,7 @@
 #define WS_MAGIC_STRING "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
 #define WS_KEY_LEN 24
 #define MAX_HEADER_SIZE 4096
-#define MAX_FRAME_SIZE 65536
-
-// Debug logging (conditional compilation)
-#if defined(ENABLE_FILE_LOGGING) && defined(ENABLE_WEBSOCKET_LOGGING)
-static FILE* debug_log_file = NULL;
-static void debug_log_init(void);
-static void debug_log_message(const char* direction, const char* host, int port, const char* message);
-static const char* get_timestamp(void);
-#endif
+#define MAX_FRAME_SIZE 262144
 
 // Transport layer abstraction
 typedef struct {
@@ -52,6 +57,15 @@ typedef struct {
     SSL_CTX* ssl_ctx;
     SSL* ssl;
     int ssl_connected;
+    /* Internal read buffer: SSL_read may return more bytes than the
+     * caller requested (a full TLS record at once). Without buffering
+     * the excess, those bytes are lost — which breaks ws_receive_frame
+     * when it asks for a 2-byte header but SSL_read returns a full
+     * event message. This caused the caching backfill to only receive
+     * 1 event per query from TLS relays. */
+    char read_buf[65536];
+    size_t read_buf_len;   /* total bytes in read_buf */
+    size_t read_buf_pos;   /* offset of next byte to consume */
 } tls_transport_t;
 
 // WebSocket client structure
@@ -131,7 +145,7 @@ static void init_openssl(void) {
 
 nostr_ws_client_t* nostr_ws_connect(const char* url) {
     if (!url) return NULL;
-    
+
     // Initialize OpenSSL
     init_openssl();
     
@@ -425,35 +439,159 @@ const char* nostr_ws_strerror(int error_code) {
 
 static int tcp_connect(void* ctx, const char* host, int port) {
     tcp_transport_t* tcp = (tcp_transport_t*)ctx;
-    
-    // Create socket
-    tcp->socket_fd = socket(AF_INET, SOCK_STREAM, 0);
+    struct addrinfo hints;
+    struct addrinfo* result = NULL;
+    struct addrinfo* rp = NULL;
+    char port_str[16];
+    int ret;
+    int addr_idx = 0;
+    time_t connect_start = time(NULL);
+
+    if (ws_connect_debug_enabled()) {
+        fprintf(stderr, "[nostr_ws][connect] tcp_connect_start host=%s port=%d\n", host ? host : "(null)", port);
+    }
+
+    tcp->socket_fd = -1;
+
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_family = AF_UNSPEC;      // IPv4 or IPv6
+    hints.ai_socktype = SOCK_STREAM;
+    hints.ai_protocol = IPPROTO_TCP;
+
+    snprintf(port_str, sizeof(port_str), "%d", port);
+    ret = getaddrinfo(host, port_str, &hints, &result);
+    if (ret != 0 || !result) {
+        if (ws_connect_debug_enabled()) {
+            fprintf(stderr, "[nostr_ws][connect] getaddrinfo_failed host=%s port=%d ret=%d err=%s\n",
+                    host ? host : "(null)",
+                    port,
+                    ret,
+                    gai_strerror(ret));
+        }
+        return -1;
+    }
+
+    for (rp = result; rp != NULL; rp = rp->ai_next) {
+        int fd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+        addr_idx++;
+        if (fd < 0) {
+            if (ws_connect_debug_enabled()) {
+                fprintf(stderr, "[nostr_ws][connect] socket_failed host=%s port=%d addr_idx=%d family=%d errno=%d\n",
+                        host ? host : "(null)",
+                        port,
+                        addr_idx,
+                        rp->ai_family,
+                        errno);
+            }
+            continue;
+        }
+
+        if (ws_connect_debug_enabled()) {
+            fprintf(stderr, "[nostr_ws][connect] connect_attempt host=%s port=%d addr_idx=%d family=%d\n",
+                    host ? host : "(null)",
+                    port,
+                    addr_idx,
+                    rp->ai_family);
+        }
+
+        int flags = fcntl(fd, F_GETFL, 0);
+        if (flags >= 0) {
+            (void)fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+        }
+
+        int connect_rc = connect(fd, rp->ai_addr, rp->ai_addrlen);
+        if (connect_rc == 0) {
+            tcp->socket_fd = fd;
+            if (flags >= 0) {
+                (void)fcntl(fd, F_SETFL, flags);
+            }
+            if (ws_connect_debug_enabled()) {
+                fprintf(stderr, "[nostr_ws][connect] connect_success host=%s port=%d addr_idx=%d elapsed_s=%ld\n",
+                        host ? host : "(null)",
+                        port,
+                        addr_idx,
+                        (long)(time(NULL) - connect_start));
+            }
+            break;
+        }
+
+        if (connect_rc < 0 && errno == EINPROGRESS) {
+            fd_set wfds;
+            struct timeval tv;
+            int sel_rc;
+            int so_error = 0;
+            socklen_t so_error_len = sizeof(so_error);
+
+            FD_ZERO(&wfds);
+            FD_SET(fd, &wfds);
+            tv.tv_sec = 5;
+            tv.tv_usec = 0;
+
+            sel_rc = select(fd + 1, NULL, &wfds, NULL, &tv);
+            if (sel_rc > 0 && FD_ISSET(fd, &wfds) &&
+                getsockopt(fd, SOL_SOCKET, SO_ERROR, &so_error, &so_error_len) == 0 &&
+                so_error == 0) {
+                tcp->socket_fd = fd;
+                if (flags >= 0) {
+                    (void)fcntl(fd, F_SETFL, flags);
+                }
+                if (ws_connect_debug_enabled()) {
+                    fprintf(stderr, "[nostr_ws][connect] connect_success_after_wait host=%s port=%d addr_idx=%d elapsed_s=%ld\n",
+                            host ? host : "(null)",
+                            port,
+                            addr_idx,
+                            (long)(time(NULL) - connect_start));
+                }
+                break;
+            }
+
+            if (ws_connect_debug_enabled()) {
+                fprintf(stderr, "[nostr_ws][connect] connect_timeout_or_error host=%s port=%d addr_idx=%d select_rc=%d so_error=%d elapsed_s=%ld\n",
+                        host ? host : "(null)",
+                        port,
+                        addr_idx,
+                        sel_rc,
+                        so_error,
+                        (long)(time(NULL) - connect_start));
+            }
+        } else if (ws_connect_debug_enabled()) {
+            fprintf(stderr, "[nostr_ws][connect] connect_failed host=%s port=%d addr_idx=%d errno=%d elapsed_s=%ld\n",
+                    host ? host : "(null)",
+                    port,
+                    addr_idx,
+                    errno,
+                    (long)(time(NULL) - connect_start));
+        }
+
+        close(fd);
+    }
+
+    freeaddrinfo(result);
+
     if (tcp->socket_fd < 0) {
+        if (ws_connect_debug_enabled()) {
+            fprintf(stderr, "[nostr_ws][connect] tcp_connect_end host=%s port=%d rc=-1 elapsed_s=%ld\n",
+                    host ? host : "(null)",
+                    port,
+                    (long)(time(NULL) - connect_start));
+        }
         return -1;
     }
-    
-    // Resolve hostname
-    struct hostent* he = gethostbyname(host);
-    if (!he) {
-        close(tcp->socket_fd);
-        tcp->socket_fd = -1;
-        return -1;
+
+    // Safety timeout: prevent indefinite blocking in recv/send on half-broken sockets.
+    struct timeval io_timeout;
+    io_timeout.tv_sec = 5;
+    io_timeout.tv_usec = 0;
+    (void)setsockopt(tcp->socket_fd, SOL_SOCKET, SO_RCVTIMEO, &io_timeout, sizeof(io_timeout));
+    (void)setsockopt(tcp->socket_fd, SOL_SOCKET, SO_SNDTIMEO, &io_timeout, sizeof(io_timeout));
+
+    if (ws_connect_debug_enabled()) {
+        fprintf(stderr, "[nostr_ws][connect] tcp_connect_end host=%s port=%d rc=0 elapsed_s=%ld\n",
+                host ? host : "(null)",
+                port,
+                (long)(time(NULL) - connect_start));
     }
-    
-    // Set up address
-    struct sockaddr_in addr;
-    memset(&addr, 0, sizeof(addr));
-    addr.sin_family = AF_INET;
-    addr.sin_port = htons(port);
-    memcpy(&addr.sin_addr, he->h_addr_list[0], he->h_length);
-    
-    // Connect
-    if (connect(tcp->socket_fd, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
-        close(tcp->socket_fd);
-        tcp->socket_fd = -1;
-        return -1;
-    }
-    
+
     return 0;
 }
 
@@ -579,24 +717,47 @@ static int tls_recv(void* ctx, void* data, size_t len, int timeout_ms) {
     if (!tls->ssl_connected || !tls->ssl) {
         return -1;
     }
-    
-    // Check if SSL has pending data first
-    if (SSL_pending(tls->ssl) == 0 && timeout_ms > 0) {
-        // Only use select() if no data is pending in SSL buffers
+
+    /* Serve from the internal read buffer first. SSL_read may have
+     * returned more bytes than the caller requested on a previous call
+     * (a full TLS record), and we buffered the excess. Without this,
+     * ws_receive_frame loses the extra bytes when it asks for a 2-byte
+     * header but SSL_read returns a full event message. */
+    if (tls->read_buf_pos < tls->read_buf_len) {
+        size_t avail = tls->read_buf_len - tls->read_buf_pos;
+        size_t to_copy = (avail < len) ? avail : len;
+        memcpy(data, tls->read_buf + tls->read_buf_pos, to_copy);
+        tls->read_buf_pos += to_copy;
+        if (tls->read_buf_pos >= tls->read_buf_len) {
+            tls->read_buf_len = 0;
+            tls->read_buf_pos = 0;
+        }
+        return (int)to_copy;
+    }
+
+    /* Buffer is empty — refill it with a single SSL_read, then serve
+     * the requested bytes from it. This ensures excess bytes are
+     * preserved for subsequent tls_recv calls. */
+    if (timeout_ms > 0) {
         fd_set readfds;
         struct timeval tv;
         
         FD_ZERO(&readfds);
         FD_SET(tls->socket_fd, &readfds);
         
-        tv.tv_sec = timeout_ms / 1000;
-        tv.tv_usec = (timeout_ms % 1000) * 1000;
+        if (SSL_pending(tls->ssl) > 0) {
+            tv.tv_sec = 0;
+            tv.tv_usec = 0;
+        } else {
+            tv.tv_sec = timeout_ms / 1000;
+            tv.tv_usec = (timeout_ms % 1000) * 1000;
+        }
         
         int result = select(tls->socket_fd + 1, &readfds, NULL, NULL, &tv);
         if (result < 0) {
             return -1;
-        } else if (result == 0) {
-            return -1; // Timeout
+        } else if (result == 0 && SSL_pending(tls->ssl) == 0) {
+            return -1; // Timeout with no pending data
         }
     }
     
@@ -605,16 +766,26 @@ static int tls_recv(void* ctx, void* data, size_t len, int timeout_ms) {
     const int max_attempts = 10;
     
     while (attempts < max_attempts) {
-        int ret = SSL_read(tls->ssl, data, len);
+        /* Read into the internal buffer (up to its capacity), then copy
+         * the requested number of bytes to the caller's output. */
+        int ret = SSL_read(tls->ssl, tls->read_buf, sizeof(tls->read_buf));
         
         if (ret > 0) {
-            return ret; // Success
+            tls->read_buf_len = (size_t)ret;
+            tls->read_buf_pos = 0;
+            size_t to_copy = (tls->read_buf_len < len) ? tls->read_buf_len : len;
+            memcpy(data, tls->read_buf, to_copy);
+            tls->read_buf_pos = to_copy;
+            if (tls->read_buf_pos >= tls->read_buf_len) {
+                tls->read_buf_len = 0;
+                tls->read_buf_pos = 0;
+            }
+            return (int)to_copy;
         }
         
         int err = SSL_get_error(tls->ssl, ret);
         
         if (err == SSL_ERROR_WANT_READ) {
-            // Check if more data is available on socket
             fd_set readfds;
             struct timeval tv = {0, 100000}; // 100ms timeout
             
@@ -627,7 +798,7 @@ static int tls_recv(void* ctx, void* data, size_t len, int timeout_ms) {
             }
             
             attempts++;
-            continue; // Retry the SSL read
+            continue;
             
         } else if (err == SSL_ERROR_WANT_WRITE) {
             return -1;
@@ -781,32 +952,35 @@ static int ws_perform_handshake(nostr_ws_client_t* client, const char* key) {
     // Read response
     char response[MAX_HEADER_SIZE];
     int total_received = 0;
-    
+
     while ((size_t)total_received < sizeof(response) - 1) {
-        int received = client->transport->recv(&client->transport_ctx, 
-                                             response + total_received, 
-                                             sizeof(response) - total_received - 1, 
-                                             client->timeout_ms);
+        int received = client->transport->recv(&client->transport_ctx,
+                                              response + total_received,
+                                              sizeof(response) - total_received - 1,
+                                              client->timeout_ms);
         if (received <= 0) {
             return -1;
         }
-        
+
         total_received += received;
         response[total_received] = '\0';
-        
+
         // Check if we have complete headers
-        if (strstr(response, "\r\n\r\n")) break;
+        if (strstr(response, "\r\n\r\n")) {
+            break;
+        }
     }
     
     // Check if response starts with the correct HTTP status line
     if (strncmp(response, "HTTP/1.1 101 Switching Protocols\r\n", 34) != 0) {
         return -1;
     }
-    
-    if (!strstr(response, "Upgrade: websocket") && !strstr(response, "upgrade: websocket")) {
+
+    if (!strstr(response, "Upgrade: websocket") && !strstr(response, "upgrade: websocket") &&
+        !strstr(response, "Upgrade: WebSocket") && !strstr(response, "upgrade: WebSocket")) {
         return -1;
     }
-    
+
     return 0;
 }
 
@@ -850,10 +1024,15 @@ static int ws_send_frame(nostr_ws_client_t* client, ws_opcode_t opcode, const ch
         frame_len += payload_len;
     }
     
-    // Log outgoing message to debug.log
-#if defined(ENABLE_FILE_LOGGING) && defined(ENABLE_WEBSOCKET_LOGGING)
+    // Emit outgoing message to consumer callback logger
+#if defined(ENABLE_WEBSOCKET_LOGGING)
     if (opcode == WS_OPCODE_TEXT && payload && payload_len > 0) {
-        debug_log_message("SEND", client->host, client->port, payload);
+        nostr_log_emitf(NOSTR_LOG_LEVEL_TRACE,
+                        "websocket",
+                        "SEND %s:%d: %s",
+                        client->host ? client->host : "",
+                        client->port,
+                        payload);
     }
 #endif
     
@@ -866,13 +1045,22 @@ static int ws_send_frame(nostr_ws_client_t* client, ws_opcode_t opcode, const ch
 static int ws_receive_frame(nostr_ws_client_t* client, ws_opcode_t* opcode, char* payload, size_t* payload_len, int timeout_ms) {
     if (!client || !opcode || !payload || !payload_len) return -1;
     
-    char header[14]; // Max header size
+    unsigned char header[14]; // Max header size
     size_t header_len = 2; // Minimum header size
     
     // Read basic header
     int header_result = client->transport->recv(&client->transport_ctx, header, 2, timeout_ms);
     
     if (header_result != 2) {
+        if (ws_connect_debug_enabled()) {
+            fprintf(stderr,
+                    "[nostr_ws][frame] short_header host=%s port=%d got=%d expected=2 timeout_ms=%d errno=%d\n",
+                    client->host ? client->host : "(null)",
+                    client->port,
+                    header_result,
+                    timeout_ms,
+                    errno);
+        }
         return -1;
     }
     
@@ -884,12 +1072,28 @@ static int ws_receive_frame(nostr_ws_client_t* client, ws_opcode_t* opcode, char
     // Extended length
     if (len == 126) {  
         if (client->transport->recv(&client->transport_ctx, header + 2, 2, timeout_ms) != 2) {
+            if (ws_connect_debug_enabled()) {
+                fprintf(stderr,
+                        "[nostr_ws][frame] short_ext16 host=%s port=%d timeout_ms=%d errno=%d\n",
+                        client->host ? client->host : "(null)",
+                        client->port,
+                        timeout_ms,
+                        errno);
+            }
             return -1;
         }
         len = ((uint16_t)header[2] << 8) | (uint8_t)header[3];
         header_len = 4;
     } else if (len == 127) {
         if (client->transport->recv(&client->transport_ctx, header + 2, 8, timeout_ms) != 8) {
+            if (ws_connect_debug_enabled()) {
+                fprintf(stderr,
+                        "[nostr_ws][frame] short_ext64 host=%s port=%d timeout_ms=%d errno=%d\n",
+                        client->host ? client->host : "(null)",
+                        client->port,
+                        timeout_ms,
+                        errno);
+            }
             return -1;
         }
         // For simplicity, we don't support 64-bit lengths
@@ -898,15 +1102,18 @@ static int ws_receive_frame(nostr_ws_client_t* client, ws_opcode_t* opcode, char
         header_len = 10;
     }
     
-    // Check payload length
-    if (len > *payload_len) {
-        return -1;
-    }
-    
     // Read mask (if present)
     uint32_t mask = 0;
     if (masked) {
         if (client->transport->recv(&client->transport_ctx, header + header_len, 4, timeout_ms) != 4) {
+            if (ws_connect_debug_enabled()) {
+                fprintf(stderr,
+                        "[nostr_ws][frame] short_mask host=%s port=%d timeout_ms=%d errno=%d\n",
+                        client->host ? client->host : "(null)",
+                        client->port,
+                        timeout_ms,
+                        errno);
+            }
             return -1;
         }
         mask = ((uint32_t)header[header_len] << 24) |
@@ -915,6 +1122,41 @@ static int ws_receive_frame(nostr_ws_client_t* client, ws_opcode_t* opcode, char
                header[header_len + 3];
         header_len += 4;
     }
+
+    // Check payload length; if too large for caller buffer, drain frame to keep stream aligned
+    if (len > *payload_len) {
+        char discard[1024];
+        uint64_t remaining = len;
+        int drain_timeout_ms = timeout_ms < 5000 ? 5000 : timeout_ms;
+        if (ws_connect_debug_enabled()) {
+            fprintf(stderr,
+                    "[nostr_ws][frame] payload_too_large host=%s port=%d frame_len=%llu buffer_cap=%zu drain_timeout_ms=%d\n",
+                    client->host ? client->host : "(null)",
+                    client->port,
+                    (unsigned long long)len,
+                    *payload_len,
+                    drain_timeout_ms);
+        }
+        while (remaining > 0) {
+            size_t chunk = remaining > sizeof(discard) ? sizeof(discard) : (size_t)remaining;
+            int got = client->transport->recv(&client->transport_ctx, discard, chunk, drain_timeout_ms);
+            if (got <= 0) {
+                if (ws_connect_debug_enabled()) {
+                    fprintf(stderr,
+                            "[nostr_ws][frame] discard_read_failed host=%s port=%d got=%d drain_timeout_ms=%d errno=%d remaining=%llu\n",
+                            client->host ? client->host : "(null)",
+                            client->port,
+                            got,
+                            drain_timeout_ms,
+                            errno,
+                            (unsigned long long)remaining);
+                }
+                return -1;
+            }
+            remaining -= (uint64_t)got;
+        }
+        return -1;
+    }
     
     // Read payload
     if (len > 0) {
@@ -924,7 +1166,19 @@ static int ws_receive_frame(nostr_ws_client_t* client, ws_opcode_t* opcode, char
                                               payload + received, 
                                               len - received, 
                                               timeout_ms);
-            if (chunk <= 0) return -1;
+            if (chunk <= 0) {
+                if (ws_connect_debug_enabled()) {
+                    fprintf(stderr,
+                            "[nostr_ws][frame] payload_read_failed host=%s port=%d got=%d need_remaining=%zu timeout_ms=%d errno=%d\n",
+                            client->host ? client->host : "(null)",
+                            client->port,
+                            chunk,
+                            len - received,
+                            timeout_ms,
+                            errno);
+                }
+                return -1;
+            }
             received += chunk;
         }
         
@@ -933,14 +1187,19 @@ static int ws_receive_frame(nostr_ws_client_t* client, ws_opcode_t* opcode, char
             ws_mask_payload(payload, len, mask);
         }
         
-        // Log incoming text messages to debug.log
-#if defined(ENABLE_FILE_LOGGING) && defined(ENABLE_WEBSOCKET_LOGGING)
+        // Emit incoming text messages to consumer callback logger
+#if defined(ENABLE_WEBSOCKET_LOGGING)
         if (*opcode == WS_OPCODE_TEXT && len > 0) {
             // Null terminate for logging
             char temp_payload[len + 1];
             memcpy(temp_payload, payload, len);
             temp_payload[len] = '\0';
-            debug_log_message("RECV", client->host, client->port, temp_payload);
+            nostr_log_emitf(NOSTR_LOG_LEVEL_TRACE,
+                            "websocket",
+                            "RECV %s:%d: %s",
+                            client->host ? client->host : "",
+                            client->port,
+                            temp_payload);
         }
 #endif
     }
@@ -971,44 +1230,3 @@ static uint32_t ws_generate_mask(void) {
     return ((uint32_t)rand() << 16) | ((uint32_t)rand() & 0xFFFF);
 }
 
-// ============================================================================
-// Debug Logging Functions
-// ============================================================================
-
-#if defined(ENABLE_FILE_LOGGING) && defined(ENABLE_WEBSOCKET_LOGGING)
-static void debug_log_init(void) {
-    if (!debug_log_file) {
-        debug_log_file = fopen("debug.log", "a");
-        if (debug_log_file) {
-            fprintf(debug_log_file, "\n=== NOSTR WebSocket Debug Log Started ===\n");
-            fflush(debug_log_file);
-        }
-    }
-}
-
-
-static const char* get_timestamp(void) {
-    static char timestamp[32];
-    struct timespec ts;
-    struct tm *timeinfo;
-    
-    clock_gettime(CLOCK_REALTIME, &ts);
-    timeinfo = localtime(&ts.tv_sec);
-    
-    // Format: HH:MM:SS.mmm (with milliseconds)
-    strftime(timestamp, sizeof(timestamp), "%H:%M:%S", timeinfo);
-    snprintf(timestamp + 8, sizeof(timestamp) - 8, ".%03ld", ts.tv_nsec / 1000000);
-    
-    return timestamp;
-}
-
-static void debug_log_message(const char* direction, const char* host, int port, const char* message) {
-    debug_log_init();
-    
-    if (debug_log_file) {
-        fprintf(debug_log_file, "[%s] %s %s:%d: %s\n", 
-                get_timestamp(), direction, host, port, message);
-        fflush(debug_log_file);
-    }
-}
-#endif

plans/logging_delegation_plan.md

@@ -0,0 +1,148 @@
+# Logging Delegation Plan for `nostr_core_lib`
+
+## Objective
+
+Refactor `nostr_core_lib` so it does not own log destinations such as `debug.log`, and instead emits logs through a consumer-provided callback. This allows host applications such as [`didactyl`](../README.md) to route all library logs into their own logging system with consistent formatting, level control, and file policy.
+
+## Current State and Problem
+
+The library currently writes directly to `debug.log` in multiple places:
+
+- [`nostr_core_lib/nostr_websocket/nostr_websocket_openssl.c`](../nostr_websocket/nostr_websocket_openssl.c:1008)
+- [`nostr_core_lib/nostr_core/nip013.c`](../nostr_core/nip013.c:178)
+- [`nostr_core_lib/nostr_core/nip013.c`](../nostr_core/nip013.c:242)
+- [`nostr_core_lib/nostr_core/nip013.c`](../nostr_core/nip013.c:270)
+
+This creates collisions with consumer logs when the host app also uses `debug.log` such as [`didactyl/src/debug.c`](../../src/debug.c:18).
+
+## Target Design
+
+Adopt a callback-based logging API inside `nostr_core_lib`:
+
+1. Library owns no file handle for logs.
+2. Library emits structured log events by level and source.
+3. Consumer registers a callback once during startup.
+4. If no callback is set, logs are dropped by default.
+
+### High-Level Flow
+
+```mermaid
+flowchart TD
+    A[nostr_core_lib internal code] --> B[nostr_log_emit level source message]
+    B --> C{callback configured}
+    C -->|Yes| D[consumer callback]
+    C -->|No| E[drop log event]
+    D --> F[didactyl debug_log routing]
+    F --> G[didactyl log file or stdout]
+```
+
+## API Additions
+
+Add a small public logging API in [`nostr_core_lib/nostr_core/nostr_core.h`](../nostr_core/nostr_core.h):
+
+- `nostr_log_level_t` enum with levels compatible with host systems
+- `nostr_log_callback_t` callback type
+- `void nostr_set_log_callback(nostr_log_callback_t cb, void* user_data);`
+- `void nostr_set_log_level(nostr_log_level_t min_level);`
+
+Recommended callback shape:
+
+```c
+typedef void (*nostr_log_callback_t)(
+    int level,
+    const char* component,
+    const char* message,
+    void* user_data
+);
+```
+
+Notes:
+- Keep ABI simple by formatting message inside the library before callback invocation.
+- Include `component` values such as `websocket` and `nip013`.
+
+## Internal Implementation Plan
+
+## Phase 1: Logging Core
+
+1. Create `nostr_core_lib/nostr_core/nostr_log.h` and `nostr_core_lib/nostr_core/nostr_log.c`.
+2. Add internal singleton state:
+   - callback pointer
+   - callback user data
+   - minimum log level
+3. Add internal helpers:
+   - `nostr_log_emitf level component fmt ...`
+   - stack buffer formatting with truncation safety
+4. Default behavior when no callback set: no-op.
+
+## Phase 2: Replace File Logging in WebSocket Layer
+
+1. Remove file-specific static globals from [`nostr_websocket_openssl.c`](../nostr_websocket/nostr_websocket_openssl.c:27).
+2. Remove `debug_log_init` and `debug_log_message` path at [`nostr_websocket_openssl.c`](../nostr_websocket/nostr_websocket_openssl.c:1005).
+3. Replace call sites:
+   - outgoing frame logging near [`nostr_websocket_openssl.c`](../nostr_websocket/nostr_websocket_openssl.c:871)
+   - incoming frame logging near [`nostr_websocket_openssl.c`](../nostr_websocket/nostr_websocket_openssl.c:964)
+4. Emit through `nostr_log_emitf` with component `websocket`.
+
+## Phase 3: Replace File Logging in NIP-13
+
+1. Replace `fopen`/`fprintf` blocks in [`nip013.c`](../nostr_core/nip013.c:178), [`nip013.c`](../nostr_core/nip013.c:242), and [`nip013.c`](../nostr_core/nip013.c:270).
+2. Emit equivalent debug lines via `nostr_log_emitf` with component `nip013`.
+3. Preserve existing compile-time verbosity guards if needed, but route output through callback.
+
+## Phase 4: Wire Public API
+
+1. Export new functions in [`nostr_core.h`](../nostr_core/nostr_core.h:1).
+2. Ensure object file inclusion in `nostr_core_lib` build scripts and static archive.
+3. Document behavior in [`nostr_core_lib/README.md`](../README.md).
+
+## Phase 5: Consumer Integration in Didactyl
+
+1. In didactyl initialization path near [`src/nostr_handler.c`](../../src/nostr_handler.c:1519), register `nostr_set_log_callback`.
+2. Adapter callback maps library levels to didactyl levels from [`src/debug.h`](../../src/debug.h:7).
+3. Prefix messages with source namespace such as `[nostr:websocket]` and `[nostr:nip013]`.
+
+## Backward Compatibility Strategy
+
+- Keep existing compile guards but change behavior from file output to callback emission.
+- If callback not set, behavior remains safe and silent.
+- No breaking changes for consumers not using logging.
+
+## Testing Plan
+
+### Unit Tests in `nostr_core_lib`
+
+1. Add tests for callback registration and null behavior.
+2. Add tests for level filtering.
+3. Add tests that message formatting truncates safely and remains null terminated.
+
+### Integration Checks in Didactyl
+
+1. Start didactyl with debug enabled and callback wired.
+2. Verify websocket SEND and RECV lines appear through didactyl logger format from [`src/debug.c`](../../src/debug.c:31).
+3. Verify no separate websocket-only banner line from old path near [`nostr_websocket_openssl.c`](../nostr_websocket/nostr_websocket_openssl.c:1010).
+4. Verify LLM request log lines and nostr logs coexist in one log destination.
+
+## Rollout Steps
+
+1. Implement callback infrastructure and migrate websocket logging first.
+2. Validate no direct file writes remain in websocket module.
+3. Migrate nip013 logging.
+4. Add documentation and examples.
+5. Update didactyl wiring.
+6. Remove obsolete references to `ENABLE_FILE_LOGGING` for websocket logging behavior if no longer needed.
+
+## Risks and Mitigations
+
+- Risk: excessive callback volume from websocket trace traffic.
+  - Mitigation: implement minimum level filter in library and map websocket traffic to trace level.
+- Risk: callback reentrancy or thread concerns.
+  - Mitigation: document callback must be fast and thread-safe, avoid heavy blocking in callback.
+- Risk: API drift across consumers.
+  - Mitigation: keep callback signature minimal and stable.
+
+## Definition of Done
+
+- No direct `fopen("debug.log", ...)` remains in production logging paths in `nostr_core_lib`.
+- Consumer can set callback and receive websocket and nip013 logs.
+- Didactyl routes nostr_core_lib logs through its logger and single configured destination.
+- Documentation updated with migration and usage examples.