v0.2.18 - Clean up configuration system: remove active_config VIEW, database_location field, fix double slash in paths, and ensure database_path reflects actual path used

- Add --database-path/-D command line parameter for database override
- Store actual database and config file paths as metadata in config tables
- Fix circular dependency by making command line overrides runtime-only
- Support multiple relay instances with separate databases and configurations
- Clean path normalization removes redundant ./ prefixes
- New fields: database_location and config_location for tracking actual usage

.gitignore

@@ -1,3 +1,10 @@
 nostr_core_lib/
 nips/
 build/
+relay.log
+relay.pid
+Trash/
+src/version.h
+dev-config/
+db/
+copy_executable_local.sh

.roo/rules-code/rules.md

@@ -0,0 +1 @@
+Use ./make_and_restart_relay.sh instead of make to build the project. 

Makefile

@@ -9,7 +9,7 @@ LIBS = -lsqlite3 -lwebsockets -lz -ldl -lpthread -lm -L/usr/local/lib -lsecp256k
 BUILD_DIR = build
 
 # Source files
-MAIN_SRC = src/main.c
+MAIN_SRC = src/main.c src/config.c
 NOSTR_CORE_LIB = nostr_core_lib/libnostr_core_x64.a
 
 # Architecture detection
@@ -36,19 +36,69 @@ $(NOSTR_CORE_LIB):
 	@echo "Building nostr_core_lib..."
 	cd nostr_core_lib && ./build.sh
 
+# Generate version.h from git tags
+src/version.h:
+	@if [ -d .git ]; then \
+		echo "Generating version.h from git tags..."; \
+		RAW_VERSION=$$(git describe --tags --always 2>/dev/null || echo "unknown"); \
+		if echo "$$RAW_VERSION" | grep -q "^v[0-9]"; then \
+			CLEAN_VERSION=$$(echo "$$RAW_VERSION" | sed 's/^v//' | cut -d- -f1); \
+			VERSION="v$$CLEAN_VERSION"; \
+			MAJOR=$$(echo "$$CLEAN_VERSION" | cut -d. -f1); \
+			MINOR=$$(echo "$$CLEAN_VERSION" | cut -d. -f2); \
+			PATCH=$$(echo "$$CLEAN_VERSION" | cut -d. -f3); \
+		else \
+			VERSION="v0.0.0"; \
+			MAJOR=0; MINOR=0; PATCH=0; \
+		fi; \
+		echo "/* Auto-generated version information */" > src/version.h; \
+		echo "#ifndef VERSION_H" >> src/version.h; \
+		echo "#define VERSION_H" >> src/version.h; \
+		echo "" >> src/version.h; \
+		echo "#define VERSION \"$$VERSION\"" >> src/version.h; \
+		echo "#define VERSION_MAJOR $$MAJOR" >> src/version.h; \
+		echo "#define VERSION_MINOR $$MINOR" >> src/version.h; \
+		echo "#define VERSION_PATCH $$PATCH" >> src/version.h; \
+		echo "" >> src/version.h; \
+		echo "#endif /* VERSION_H */" >> src/version.h; \
+		echo "Generated version.h with clean version: $$VERSION"; \
+	elif [ ! -f src/version.h ]; then \
+		echo "Git not available and version.h missing, creating fallback version.h..."; \
+		VERSION="v0.0.0"; \
+		echo "/* Auto-generated version information */" > src/version.h; \
+		echo "#ifndef VERSION_H" >> src/version.h; \
+		echo "#define VERSION_H" >> src/version.h; \
+		echo "" >> src/version.h; \
+		echo "#define VERSION \"$$VERSION\"" >> src/version.h; \
+		echo "#define VERSION_MAJOR 0" >> src/version.h; \
+		echo "#define VERSION_MINOR 0" >> src/version.h; \
+		echo "#define VERSION_PATCH 0" >> src/version.h; \
+		echo "" >> src/version.h; \
+		echo "#endif /* VERSION_H */" >> src/version.h; \
+		echo "Created fallback version.h with version: $$VERSION"; \
+	else \
+		echo "Git not available, preserving existing version.h"; \
+	fi
+
+# Force version.h regeneration (useful for development)
+force-version:
+	@echo "Force regenerating version.h..."
+	@rm -f src/version.h
+	@$(MAKE) src/version.h
+
 # Build the relay
-$(TARGET): $(BUILD_DIR) $(MAIN_SRC) $(NOSTR_CORE_LIB)
+$(TARGET): $(BUILD_DIR) src/version.h src/sql_schema.h $(MAIN_SRC) $(NOSTR_CORE_LIB)
 	@echo "Compiling C-Relay for architecture: $(ARCH)"
 	$(CC) $(CFLAGS) $(INCLUDES) $(MAIN_SRC) -o $(TARGET) $(NOSTR_CORE_LIB) $(LIBS)
 	@echo "Build complete: $(TARGET)"
 
 # Build for specific architectures
-x86: $(BUILD_DIR) $(MAIN_SRC) $(NOSTR_CORE_LIB)
+x86: $(BUILD_DIR) src/version.h src/sql_schema.h $(MAIN_SRC) $(NOSTR_CORE_LIB)
 	@echo "Building C-Relay for x86_64..."
 	$(CC) $(CFLAGS) $(INCLUDES) $(MAIN_SRC) -o $(BUILD_DIR)/c_relay_x86 $(NOSTR_CORE_LIB) $(LIBS)
 	@echo "Build complete: $(BUILD_DIR)/c_relay_x86"
 
-arm64: $(BUILD_DIR) $(MAIN_SRC) $(NOSTR_CORE_LIB)
+arm64: $(BUILD_DIR) src/version.h src/sql_schema.h $(MAIN_SRC) $(NOSTR_CORE_LIB)
 	@echo "Cross-compiling C-Relay for ARM64..."
 	@if ! command -v aarch64-linux-gnu-gcc >/dev/null 2>&1; then \
 		echo "ERROR: ARM64 cross-compiler not found."; \
@@ -112,14 +162,16 @@ test: $(TARGET)
 	@echo "Running tests..."
 	./tests/1_nip_test.sh
 
-# Initialize database
+# Initialize database (now handled automatically when server starts)
 init-db:
-	@echo "Initializing database..."
-	./db/init.sh --force
+	@echo "Database initialization is now handled automatically when the server starts."
+	@echo "The schema is embedded in the binary - no external files needed."
+	@echo "To manually recreate database: rm -f db/c_nostr_relay.db && ./build/c_relay_x86"
 
 # Clean build artifacts
 clean:
 	rm -rf $(BUILD_DIR)
+	rm -f src/version.h
 	@echo "Clean complete"
 
 # Clean everything including nostr_core_lib
@@ -158,5 +210,6 @@ help:
 	@echo "  make check-toolchain     # Check what compilers are available"
 	@echo "  make test                # Run tests"
 	@echo "  make init-db             # Set up database"
+	@echo "  make force-version       # Force regenerate version.h from git"
 
-.PHONY: all x86 arm64 test init-db clean clean-all install-deps install-cross-tools install-arm64-deps check-toolchain help
+.PHONY: all x86 arm64 test init-db clean clean-all install-deps install-cross-tools install-arm64-deps check-toolchain help force-version

README.md

@@ -14,76 +14,9 @@ Do NOT modify the formatting, add emojis, or change the text. Keep the simple fo
 - [x] NIP-13: Proof of Work
 - [x] NIP-15: End of Stored Events Notice
 - [x] NIP-20: Command Results
-- [ ] NIP-22: Event `created_at` Limits
-- [ ] NIP-25: Reactions
-- [ ] NIP-26: Delegated Event Signing
-- [ ] NIP-28: Public Chat
-- [ ] NIP-33: Parameterized Replaceable Events
-- [ ] NIP-40: Expiration Timestamp
+- [x] NIP-33: Parameterized Replaceable Events
+- [x] NIP-40: Expiration Timestamp
 - [ ] NIP-42: Authentication of clients to relays
-- [ ] NIP-45: Counting results. [experimental](#count)
-- [ ] NIP-50: Keywords filter. [experimental](#search)
+- [ ] NIP-45: Counting results.
+- [ ] NIP-50: Keywords filter.
 - [ ] NIP-70: Protected Events
-
-## NIP-13: Proof of Work Configuration
-
-The relay supports NIP-13 Proof of Work validation with configurable settings. PoW validation helps prevent spam and ensures computational commitment from event publishers.
-
-### Environment Variables
-
-Configure PoW validation using these environment variables:
-
-- `RELAY_POW_ENABLED` - Enable/disable PoW validation (default: `1`)
-  - `1`, `true`, or `yes` to enable
-  - `0`, `false`, or `no` to disable
-
-- `RELAY_MIN_POW_DIFFICULTY` - Minimum required difficulty (default: `0`)
-  - Range: `0-64` (reasonable bounds)
-  - `0` = no minimum requirement (events without PoW are accepted)
-  - Higher values require more computational work
-
-- `RELAY_POW_MODE` - Validation mode (default: `basic`)
-  - `basic` - Basic PoW validation
-  - `full` - Full validation with nonce tag requirements
-  - `strict` - Strict anti-spam mode with committed target validation
-  - `disabled` - Disable PoW validation entirely
-
-### Examples
-
-```bash
-# Basic setup - accept events with or without PoW
-export RELAY_POW_ENABLED=1
-export RELAY_MIN_POW_DIFFICULTY=0
-export RELAY_POW_MODE=basic
-
-# Anti-spam setup - require minimum difficulty 16
-export RELAY_POW_ENABLED=1
-export RELAY_MIN_POW_DIFFICULTY=16
-export RELAY_POW_MODE=strict
-
-# Disable PoW validation completely
-export RELAY_POW_ENABLED=0
-```
-
-### Behavior
-
-- **min_difficulty=0**: Events without PoW are accepted; events with PoW are validated
-- **min_difficulty>0**: All events must have valid PoW meeting minimum difficulty
-- **strict mode**: Additional validation prevents difficulty commitment gaming
-- **NIP-11 integration**: PoW configuration is advertised via relay information document
-
-### Testing
-
-Run the comprehensive PoW test suite:
-
-```bash
-./tests/13_nip_test.sh
-```
-
-The test suite validates:
-- NIP-11 PoW support advertisement
-- Event acceptance without PoW (when min_difficulty=0)
-- Event validation with valid PoW
-- Configuration via environment variables
-- NIP-13 reference event validation
-

build_and_push.sh

@@ -139,6 +139,13 @@ compile_project() {
         print_warning "Clean failed or no Makefile found"
     fi
     
+    # Force regenerate version.h to pick up new tags
+    if make force-version > /dev/null 2>&1; then
+        print_success "Regenerated version.h"
+    else
+        print_warning "Failed to regenerate version.h"
+    fi
+    
     # Compile the project
     if make > /dev/null 2>&1; then
         print_success "C-Relay compiled successfully"
@@ -229,10 +236,65 @@ git_commit_and_push() {
         exit 1
     fi
     
-    if git push --tags > /dev/null 2>&1; then
-        print_success "Pushed tags"
+    # Push only the new tag to avoid conflicts with existing tags
+    if git push origin "$NEW_VERSION" > /dev/null 2>&1; then
+        print_success "Pushed tag: $NEW_VERSION"
     else
-        print_warning "Failed to push tags"
+        print_warning "Tag push failed, trying force push..."
+        if git push --force origin "$NEW_VERSION" > /dev/null 2>&1; then
+            print_success "Force-pushed updated tag: $NEW_VERSION"
+        else
+            print_error "Failed to push tag: $NEW_VERSION"
+            exit 1
+        fi
+    fi
+}
+
+# Function to commit and push changes without creating a tag (tag already created)
+git_commit_and_push_no_tag() {
+    print_status "Preparing git commit..."
+    
+    # Stage all changes
+    if git add . > /dev/null 2>&1; then
+        print_success "Staged all changes"
+    else
+        print_error "Failed to stage changes"
+        exit 1
+    fi
+    
+    # Check if there are changes to commit
+    if git diff --staged --quiet; then
+        print_warning "No changes to commit"
+    else
+        # Commit changes
+        if git commit -m "$NEW_VERSION - $COMMIT_MESSAGE" > /dev/null 2>&1; then
+            print_success "Committed changes"
+        else
+            print_error "Failed to commit changes"
+            exit 1
+        fi
+    fi
+    
+    # Push changes and tags
+    print_status "Pushing to remote repository..."
+    if git push > /dev/null 2>&1; then
+        print_success "Pushed changes"
+    else
+        print_error "Failed to push changes"
+        exit 1
+    fi
+    
+    # Push only the new tag to avoid conflicts with existing tags
+    if git push origin "$NEW_VERSION" > /dev/null 2>&1; then
+        print_success "Pushed tag: $NEW_VERSION"
+    else
+        print_warning "Tag push failed, trying force push..."
+        if git push --force origin "$NEW_VERSION" > /dev/null 2>&1; then
+            print_success "Force-pushed updated tag: $NEW_VERSION"
+        else
+            print_error "Failed to push tag: $NEW_VERSION"
+            exit 1
+        fi
     fi
 }
 
@@ -352,14 +414,23 @@ main() {
         # Increment minor version for releases
         increment_version "minor"
         
-        # Compile project first
+        # Create new git tag BEFORE compilation so version.h picks it up
+        if git tag "$NEW_VERSION" > /dev/null 2>&1; then
+            print_success "Created tag: $NEW_VERSION"
+        else
+            print_warning "Tag $NEW_VERSION already exists, removing and recreating..."
+            git tag -d "$NEW_VERSION" > /dev/null 2>&1
+            git tag "$NEW_VERSION" > /dev/null 2>&1
+        fi
+        
+        # Compile project first (will now pick up the new tag)
         compile_project
         
         # Build release binaries
         build_release_binaries
         
-        # Commit and push
-        git_commit_and_push
+        # Commit and push (but skip tag creation since we already did it)
+        git_commit_and_push_no_tag
         
         # Create Gitea release with binaries
         create_gitea_release
@@ -376,11 +447,20 @@ main() {
         # Increment patch version for regular commits
         increment_version "patch"
         
-        # Compile project
+        # Create new git tag BEFORE compilation so version.h picks it up
+        if git tag "$NEW_VERSION" > /dev/null 2>&1; then
+            print_success "Created tag: $NEW_VERSION"
+        else
+            print_warning "Tag $NEW_VERSION already exists, removing and recreating..."
+            git tag -d "$NEW_VERSION" > /dev/null 2>&1
+            git tag "$NEW_VERSION" > /dev/null 2>&1
+        fi
+        
+        # Compile project (will now pick up the new tag)
         compile_project
         
-        # Commit and push
-        git_commit_and_push
+        # Commit and push (but skip tag creation since we already did it)
+        git_commit_and_push_no_tag
         
         print_success "Build and push completed successfully!"
         print_status "Version $NEW_VERSION pushed to repository"

db/README.md

@@ -1,228 +1 @@
-# C Nostr Relay Database
-
-This directory contains the SQLite database schema and initialization scripts for the C Nostr Relay implementation.
-
-## Files
-
-- **`schema.sql`** - Complete database schema based on nostr-rs-relay v18
-- **`init.sh`** - Database initialization script
-- **`c_nostr_relay.db`** - SQLite database file (created after running init.sh)
-
-## Quick Start
-
-1. **Initialize the database:**
-   ```bash
-   cd db
-   ./init.sh
-   ```
-
-2. **Force reinitialize (removes existing database):**
-   ```bash
-   ./init.sh --force
-   ```
-
-3. **Initialize with optimization and info:**
-   ```bash
-   ./init.sh --info --optimize
-   ```
-
-## Database Schema
-
-The schema is fully compatible with the Nostr protocol and includes:
-
-### Core Tables
-
-- **`event`** - Main event storage with all Nostr event data
-- **`tag`** - Denormalized tag index for efficient queries
-- **`user_verification`** - NIP-05 verification tracking
-- **`account`** - User account management (optional)
-- **`invoice`** - Lightning payment tracking (optional)
-
-### Key Features
-
-- ✅ **NIP-01 compliant** - Full basic protocol support
-- ✅ **Replaceable events** - Supports kinds 0, 3, 10000-19999
-- ✅ **Parameterized replaceable** - Supports kinds 30000-39999 with `d` tags
-- ✅ **Event deletion** - NIP-09 soft deletion with `hidden` column
-- ✅ **Event expiration** - NIP-40 automatic cleanup
-- ✅ **Authentication** - NIP-42 client authentication
-- ✅ **NIP-05 verification** - Domain-based identity verification
-- ✅ **Performance optimized** - Comprehensive indexing strategy
-
-### Schema Version
-
-Current version: **v18** (compatible with nostr-rs-relay v18)
-
-## Database Structure
-
-### Event Storage
-```sql
-CREATE TABLE event (
-    id INTEGER PRIMARY KEY,
-    event_hash BLOB NOT NULL,        -- 32-byte SHA256 hash
-    first_seen INTEGER NOT NULL,     -- relay receive timestamp
-    created_at INTEGER NOT NULL,     -- event creation timestamp
-    expires_at INTEGER,              -- NIP-40 expiration
-    author BLOB NOT NULL,            -- 32-byte pubkey
-    delegated_by BLOB,               -- NIP-26 delegator
-    kind INTEGER NOT NULL,           -- event kind
-    hidden INTEGER DEFAULT FALSE,   -- soft deletion flag
-    content TEXT NOT NULL            -- complete JSON event
-);
-```
-
-### Tag Indexing
-```sql
-CREATE TABLE tag (
-    id INTEGER PRIMARY KEY,
-    event_id INTEGER NOT NULL,
-    name TEXT,                       -- tag name ("e", "p", etc.)
-    value TEXT,                      -- tag value
-    created_at INTEGER NOT NULL,     -- denormalized for performance
-    kind INTEGER NOT NULL            -- denormalized for performance
-);
-```
-
-## Performance Features
-
-### Optimized Indexes
-- **Hash-based lookups** - `event_hash_index` for O(1) event retrieval
-- **Author queries** - `author_index`, `author_created_at_index`
-- **Kind filtering** - `kind_index`, `kind_created_at_index`
-- **Tag searching** - `tag_covering_index` for efficient tag queries
-- **Composite queries** - Multi-column indexes for complex filters
-
-### Query Optimization
-- **Denormalized tags** - Includes `kind` and `created_at` in tag table
-- **Binary storage** - BLOBs for hex data (pubkeys, hashes)
-- **WAL mode** - Write-Ahead Logging for concurrent access
-- **Automatic cleanup** - Triggers for data integrity
-
-## Usage Examples
-
-### Basic Operations
-
-1. **Insert an event:**
-   ```sql
-   INSERT INTO event (event_hash, first_seen, created_at, author, kind, content)
-   VALUES (?, ?, ?, ?, ?, ?);
-   ```
-
-2. **Query by author:**
-   ```sql
-   SELECT content FROM event 
-   WHERE author = ? AND hidden != TRUE
-   ORDER BY created_at DESC;
-   ```
-
-3. **Filter by tags:**
-   ```sql
-   SELECT e.content FROM event e
-   JOIN tag t ON e.id = t.event_id
-   WHERE t.name = 'p' AND t.value = ? AND e.hidden != TRUE;
-   ```
-
-### Advanced Queries
-
-1. **Get replaceable event (latest only):**
-   ```sql
-   SELECT content FROM event
-   WHERE author = ? AND kind = ? AND hidden != TRUE
-   ORDER BY created_at DESC LIMIT 1;
-   ```
-
-2. **Tag-based filtering (NIP-01 filters):**
-   ```sql
-   SELECT e.content FROM event e
-   WHERE e.id IN (
-     SELECT t.event_id FROM tag t
-     WHERE t.name = ? AND t.value IN (?, ?, ?)
-   ) AND e.hidden != TRUE;
-   ```
-
-## Maintenance
-
-### Regular Operations
-
-1. **Check database integrity:**
-   ```bash
-   sqlite3 c_nostr_relay.db "PRAGMA integrity_check;"
-   ```
-
-2. **Optimize database:**
-   ```bash
-   sqlite3 c_nostr_relay.db "PRAGMA optimize; VACUUM; ANALYZE;"
-   ```
-
-3. **Clean expired events:**
-   ```sql
-   DELETE FROM event WHERE expires_at <= strftime('%s', 'now');
-   ```
-
-### Monitoring
-
-1. **Database size:**
-   ```bash
-   ls -lh c_nostr_relay.db
-   ```
-
-2. **Table statistics:**
-   ```sql
-   SELECT name, COUNT(*) as count FROM (
-     SELECT 'events' as name FROM event UNION ALL
-     SELECT 'tags' as name FROM tag UNION ALL
-     SELECT 'verifications' as name FROM user_verification
-   ) GROUP BY name;
-   ```
-
-## Migration Support
-
-The schema includes a migration system for future updates:
-
-```sql
-CREATE TABLE schema_info (
-    version INTEGER PRIMARY KEY,
-    applied_at INTEGER NOT NULL,
-    description TEXT
-);
-```
-
-## Security Considerations
-
-1. **Input validation** - Always validate event JSON and signatures
-2. **Rate limiting** - Implement at application level
-3. **Access control** - Use `account` table for permissions
-4. **Backup strategy** - Regular database backups recommended
-
-## Compatibility
-
-- **SQLite version** - Requires SQLite 3.8.0+
-- **nostr-rs-relay** - Schema compatible with v18
-- **NIPs supported** - 01, 02, 05, 09, 10, 11, 26, 40, 42
-- **C libraries** - Compatible with sqlite3 C API
-
-## Troubleshooting
-
-### Common Issues
-
-1. **Database locked error:**
-   - Ensure proper connection closing in your C code
-   - Check for long-running transactions
-
-2. **Performance issues:**
-   - Run `PRAGMA optimize;` regularly
-   - Consider `VACUUM` if database grew significantly
-
-3. **Schema errors:**
-   - Verify SQLite version compatibility
-   - Check foreign key constraints
-
-### Getting Help
-
-- Check the main project README for C implementation details
-- Review nostr-rs-relay documentation for reference implementation
-- Consult Nostr NIPs for protocol specifications
-
-## License
-
-This database schema is part of the C Nostr Relay project and follows the same license terms.
+Only README.md will remain

db/init.sh

@@ -1,234 +0,0 @@
-#!/bin/bash
-
-# C Nostr Relay Database Initialization Script
-# Creates and initializes the SQLite database with proper schema
-
-set -e  # Exit on any error
-
-# Configuration
-DB_DIR="$(dirname "$0")"
-DB_NAME="c_nostr_relay.db"
-DB_PATH="${DB_DIR}/${DB_NAME}"
-SCHEMA_FILE="${DB_DIR}/schema.sql"
-
-# Colors for output
-RED='\033[0;31m'
-GREEN='\033[0;32m'
-YELLOW='\033[1;33m'
-BLUE='\033[0;34m'
-NC='\033[0m' # No Color
-
-# Logging functions
-log_info() {
-    echo -e "${BLUE}[INFO]${NC} $1"
-}
-
-log_success() {
-    echo -e "${GREEN}[SUCCESS]${NC} $1"
-}
-
-log_warning() {
-    echo -e "${YELLOW}[WARNING]${NC} $1"
-}
-
-log_error() {
-    echo -e "${RED}[ERROR]${NC} $1"
-}
-
-# Check if SQLite3 is installed
-check_sqlite() {
-    if ! command -v sqlite3 &> /dev/null; then
-        log_error "sqlite3 is not installed. Please install it first:"
-        echo "  Ubuntu/Debian: sudo apt-get install sqlite3"
-        echo "  CentOS/RHEL:   sudo yum install sqlite"
-        echo "  macOS:         brew install sqlite3"
-        exit 1
-    fi
-    
-    local version=$(sqlite3 --version | cut -d' ' -f1)
-    log_info "Using SQLite version: $version"
-}
-
-# Create database directory if it doesn't exist
-create_db_directory() {
-    if [ ! -d "$DB_DIR" ]; then
-        log_info "Creating database directory: $DB_DIR"
-        mkdir -p "$DB_DIR"
-    fi
-}
-
-# Backup existing database if it exists
-backup_existing_db() {
-    if [ -f "$DB_PATH" ]; then
-        local backup_path="${DB_PATH}.backup.$(date +%Y%m%d_%H%M%S)"
-        log_warning "Existing database found. Creating backup: $backup_path"
-        cp "$DB_PATH" "$backup_path"
-    fi
-}
-
-# Initialize the database with schema
-init_database() {
-    log_info "Initializing database: $DB_PATH"
-    
-    if [ ! -f "$SCHEMA_FILE" ]; then
-        log_error "Schema file not found: $SCHEMA_FILE"
-        exit 1
-    fi
-    
-    # Remove existing database if --force flag is used
-    if [ "$1" = "--force" ] && [ -f "$DB_PATH" ]; then
-        log_warning "Force flag detected. Removing existing database."
-        rm -f "$DB_PATH"
-    fi
-    
-    # Create the database and apply schema
-    log_info "Applying schema from: $SCHEMA_FILE"
-    if sqlite3 "$DB_PATH" < "$SCHEMA_FILE"; then
-        log_success "Database schema applied successfully"
-    else
-        log_error "Failed to apply database schema"
-        exit 1
-    fi
-}
-
-# Verify database integrity
-verify_database() {
-    log_info "Verifying database integrity..."
-    
-    # Check if database file exists and is not empty
-    if [ ! -s "$DB_PATH" ]; then
-        log_error "Database file is empty or doesn't exist"
-        exit 1
-    fi
-    
-    # Run SQLite integrity check
-    local integrity_result=$(sqlite3 "$DB_PATH" "PRAGMA integrity_check;")
-    if [ "$integrity_result" = "ok" ]; then
-        log_success "Database integrity check passed"
-    else
-        log_error "Database integrity check failed: $integrity_result"
-        exit 1
-    fi
-    
-    # Verify schema version
-    local schema_version=$(sqlite3 "$DB_PATH" "PRAGMA user_version;")
-    log_info "Database schema version: $schema_version"
-    
-    # Check that main tables exist
-    local table_count=$(sqlite3 "$DB_PATH" "SELECT count(*) FROM sqlite_master WHERE type='table' AND name IN ('events', 'schema_info');")
-    if [ "$table_count" -eq 2 ]; then
-        log_success "Core tables created successfully"
-    else
-        log_error "Missing core tables (expected 2, found $table_count)"
-        exit 1
-    fi
-}
-
-# Display database information
-show_db_info() {
-    log_info "Database Information:"
-    echo "  Location: $DB_PATH"
-    echo "  Size: $(du -h "$DB_PATH" | cut -f1)"
-    
-    log_info "Database Tables:"
-    sqlite3 "$DB_PATH" "SELECT name FROM sqlite_master WHERE type='table' ORDER BY name;" | sed 's/^/  - /'
-    
-    log_info "Database Indexes:"
-    sqlite3 "$DB_PATH" "SELECT name FROM sqlite_master WHERE type='index' AND name NOT LIKE 'sqlite_%' ORDER BY name;" | sed 's/^/  - /'
-    
-    log_info "Database Views:"
-    sqlite3 "$DB_PATH" "SELECT name FROM sqlite_master WHERE type='view' ORDER BY name;" | sed 's/^/  - /'
-}
-
-# Run database optimization
-optimize_database() {
-    log_info "Running database optimization..."
-    sqlite3 "$DB_PATH" "PRAGMA optimize; VACUUM; ANALYZE;"
-    log_success "Database optimization completed"
-}
-
-# Print usage information
-print_usage() {
-    echo "Usage: $0 [OPTIONS]"
-    echo ""
-    echo "Initialize SQLite database for C Nostr Relay"
-    echo ""
-    echo "Options:"
-    echo "  --force     Remove existing database before initialization"
-    echo "  --info      Show database information after initialization"
-    echo "  --optimize  Run database optimization after initialization"
-    echo "  --help      Show this help message"
-    echo ""
-    echo "Examples:"
-    echo "  $0                    # Initialize database (with backup if exists)"
-    echo "  $0 --force           # Force reinitialize database"
-    echo "  $0 --info --optimize # Initialize with info and optimization"
-}
-
-# Main execution
-main() {
-    local force_flag=false
-    local show_info=false
-    local optimize=false
-    
-    # Parse command line arguments
-    while [[ $# -gt 0 ]]; do
-        case $1 in
-            --force)
-                force_flag=true
-                shift
-                ;;
-            --info)
-                show_info=true
-                shift
-                ;;
-            --optimize)
-                optimize=true
-                shift
-                ;;
-            --help)
-                print_usage
-                exit 0
-                ;;
-            *)
-                log_error "Unknown option: $1"
-                print_usage
-                exit 1
-                ;;
-        esac
-    done
-    
-    log_info "Starting C Nostr Relay database initialization..."
-    
-    # Execute initialization steps
-    check_sqlite
-    create_db_directory
-    
-    if [ "$force_flag" = false ]; then
-        backup_existing_db
-    fi
-    
-    if [ "$force_flag" = true ]; then
-        init_database --force
-    else
-        init_database
-    fi
-    
-    verify_database
-    
-    if [ "$optimize" = true ]; then
-        optimize_database
-    fi
-    
-    if [ "$show_info" = true ]; then
-        show_db_info
-    fi
-    
-    log_success "Database initialization completed successfully!"
-    echo ""
-    echo "Database ready at: $DB_PATH"
-    echo "You can now start your C Nostr Relay application."
-}
-
-# Execute main function with all arguments
-main "$@"

db/schema.sql

@@ -1,181 +0,0 @@
--- C Nostr Relay Database Schema
--- SQLite schema for storing Nostr events with JSON tags support
-
--- Schema version tracking
-PRAGMA user_version = 2;
-
--- Enable foreign key support
-PRAGMA foreign_keys = ON;
-
--- Optimize for performance
-PRAGMA journal_mode = WAL;
-PRAGMA synchronous = NORMAL;
-PRAGMA cache_size = 10000;
-
--- Core events table with hybrid single-table design
-CREATE TABLE events (
-    id TEXT PRIMARY KEY,                -- Nostr event ID (hex string)
-    pubkey TEXT NOT NULL,               -- Public key of event author (hex string)
-    created_at INTEGER NOT NULL,       -- Event creation timestamp (Unix timestamp)
-    kind INTEGER NOT NULL,              -- Event kind (0-65535)
-    event_type TEXT NOT NULL CHECK (event_type IN ('regular', 'replaceable', 'ephemeral', 'addressable')),
-    content TEXT NOT NULL,              -- Event content (text content only)
-    sig TEXT NOT NULL,                  -- Event signature (hex string)
-    tags JSON NOT NULL DEFAULT '[]',   -- Event tags as JSON array
-    first_seen INTEGER NOT NULL DEFAULT (strftime('%s', 'now'))  -- When relay received event
-);
-
--- Core performance indexes
-CREATE INDEX idx_events_pubkey ON events(pubkey);
-CREATE INDEX idx_events_kind ON events(kind);
-CREATE INDEX idx_events_created_at ON events(created_at DESC);
-CREATE INDEX idx_events_event_type ON events(event_type);
-
--- Composite indexes for common query patterns
-CREATE INDEX idx_events_kind_created_at ON events(kind, created_at DESC);
-CREATE INDEX idx_events_pubkey_created_at ON events(pubkey, created_at DESC);
-CREATE INDEX idx_events_pubkey_kind ON events(pubkey, kind);
-
--- Schema information table
-CREATE TABLE schema_info (
-    key TEXT PRIMARY KEY,
-    value TEXT NOT NULL,
-    updated_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now'))
-);
-
--- Insert schema metadata
-INSERT INTO schema_info (key, value) VALUES 
-    ('version', '2'),
-    ('description', 'Hybrid single-table Nostr relay schema with JSON tags'),
-    ('created_at', strftime('%s', 'now'));
-
--- Helper views for common queries
-CREATE VIEW recent_events AS
-SELECT id, pubkey, created_at, kind, event_type, content
-FROM events
-WHERE event_type != 'ephemeral'
-ORDER BY created_at DESC
-LIMIT 1000;
-
-CREATE VIEW event_stats AS
-SELECT 
-    event_type,
-    COUNT(*) as count,
-    AVG(length(content)) as avg_content_length,
-    MIN(created_at) as earliest,
-    MAX(created_at) as latest
-FROM events
-GROUP BY event_type;
-
--- Optimization: Trigger for automatic cleanup of ephemeral events older than 1 hour
-CREATE TRIGGER cleanup_ephemeral_events
-    AFTER INSERT ON events
-    WHEN NEW.event_type = 'ephemeral'
-BEGIN
-    DELETE FROM events 
-    WHERE event_type = 'ephemeral' 
-    AND first_seen < (strftime('%s', 'now') - 3600);
-END;
-
--- Replaceable event handling trigger
-CREATE TRIGGER handle_replaceable_events
-    AFTER INSERT ON events
-    WHEN NEW.event_type = 'replaceable'
-BEGIN
-    DELETE FROM events 
-    WHERE pubkey = NEW.pubkey 
-    AND kind = NEW.kind 
-    AND event_type = 'replaceable'
-    AND id != NEW.id;
-END;
-
--- Persistent Subscriptions Logging Tables (Phase 2)
--- Optional database logging for subscription analytics and debugging
-
--- Subscription events log
-CREATE TABLE subscription_events (
-    id INTEGER PRIMARY KEY AUTOINCREMENT,
-    subscription_id TEXT NOT NULL,           -- Subscription ID from client
-    client_ip TEXT NOT NULL,                 -- Client IP address
-    event_type TEXT NOT NULL CHECK (event_type IN ('created', 'closed', 'expired', 'disconnected')),
-    filter_json TEXT,                        -- JSON representation of filters (for created events)
-    events_sent INTEGER DEFAULT 0,           -- Number of events sent to this subscription
-    created_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),
-    ended_at INTEGER,                        -- When subscription ended (for closed/expired/disconnected)
-    duration INTEGER                         -- Computed: ended_at - created_at
-);
-
--- Subscription metrics summary
-CREATE TABLE subscription_metrics (
-    id INTEGER PRIMARY KEY AUTOINCREMENT,
-    date TEXT NOT NULL,                      -- Date (YYYY-MM-DD)
-    total_created INTEGER DEFAULT 0,         -- Total subscriptions created
-    total_closed INTEGER DEFAULT 0,          -- Total subscriptions closed
-    total_events_broadcast INTEGER DEFAULT 0, -- Total events broadcast
-    avg_duration REAL DEFAULT 0,            -- Average subscription duration
-    peak_concurrent INTEGER DEFAULT 0,       -- Peak concurrent subscriptions
-    updated_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),
-    UNIQUE(date)
-);
-
--- Event broadcasting log (optional, for detailed analytics)
-CREATE TABLE event_broadcasts (
-    id INTEGER PRIMARY KEY AUTOINCREMENT,
-    event_id TEXT NOT NULL,                  -- Event ID that was broadcast
-    subscription_id TEXT NOT NULL,           -- Subscription that received it
-    client_ip TEXT NOT NULL,                 -- Client IP
-    broadcast_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),
-    FOREIGN KEY (event_id) REFERENCES events(id)
-);
-
--- Indexes for subscription logging performance
-CREATE INDEX idx_subscription_events_id ON subscription_events(subscription_id);
-CREATE INDEX idx_subscription_events_type ON subscription_events(event_type);
-CREATE INDEX idx_subscription_events_created ON subscription_events(created_at DESC);
-CREATE INDEX idx_subscription_events_client ON subscription_events(client_ip);
-
-CREATE INDEX idx_subscription_metrics_date ON subscription_metrics(date DESC);
-
-CREATE INDEX idx_event_broadcasts_event ON event_broadcasts(event_id);
-CREATE INDEX idx_event_broadcasts_sub ON event_broadcasts(subscription_id);
-CREATE INDEX idx_event_broadcasts_time ON event_broadcasts(broadcast_at DESC);
-
--- Trigger to update subscription duration when ended
-CREATE TRIGGER update_subscription_duration
-    AFTER UPDATE OF ended_at ON subscription_events
-    WHEN NEW.ended_at IS NOT NULL AND OLD.ended_at IS NULL
-BEGIN
-    UPDATE subscription_events
-    SET duration = NEW.ended_at - NEW.created_at
-    WHERE id = NEW.id;
-END;
-
--- View for subscription analytics
-CREATE VIEW subscription_analytics AS
-SELECT
-    date(created_at, 'unixepoch') as date,
-    COUNT(*) as subscriptions_created,
-    COUNT(CASE WHEN ended_at IS NOT NULL THEN 1 END) as subscriptions_ended,
-    AVG(CASE WHEN duration IS NOT NULL THEN duration END) as avg_duration_seconds,
-    MAX(events_sent) as max_events_sent,
-    AVG(events_sent) as avg_events_sent,
-    COUNT(DISTINCT client_ip) as unique_clients
-FROM subscription_events
-GROUP BY date(created_at, 'unixepoch')
-ORDER BY date DESC;
-
--- View for current active subscriptions (from log perspective)
-CREATE VIEW active_subscriptions_log AS
-SELECT
-    subscription_id,
-    client_ip,
-    filter_json,
-    events_sent,
-    created_at,
-    (strftime('%s', 'now') - created_at) as duration_seconds
-FROM subscription_events
-WHERE event_type = 'created'
-AND subscription_id NOT IN (
-    SELECT subscription_id FROM subscription_events
-    WHERE event_type IN ('closed', 'expired', 'disconnected')
-);

docs/config_schema_design.md

@@ -0,0 +1,280 @@
+# Database Configuration Schema Design
+
+## Overview
+This document outlines the database configuration schema additions for the C Nostr Relay startup config file system. The design follows the Ginxsom admin system approach with signed Nostr events and database storage.
+
+## Schema Version Update
+- Current Version: 2
+- Target Version: 3
+- Update: Add server configuration management tables
+
+## Core Configuration Tables
+
+### 1. `server_config` Table
+
+```sql
+-- Server configuration table - core configuration storage
+CREATE TABLE server_config (
+    key TEXT PRIMARY KEY,                    -- Configuration key (unique identifier)
+    value TEXT NOT NULL,                     -- Configuration value (stored as string)
+    description TEXT,                        -- Human-readable description
+    config_type TEXT DEFAULT 'user' CHECK (config_type IN ('system', 'user', 'runtime')),
+    data_type TEXT DEFAULT 'string' CHECK (data_type IN ('string', 'integer', 'boolean', 'json')),
+    validation_rules TEXT,                   -- JSON validation rules (optional)
+    is_sensitive INTEGER DEFAULT 0,          -- 1 if value should be masked in logs
+    requires_restart INTEGER DEFAULT 0,      -- 1 if change requires server restart
+    created_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),
+    updated_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now'))
+);
+```
+
+**Configuration Types:**
+- `system`: Core system settings (admin keys, security)
+- `user`: User-configurable settings (relay info, features)
+- `runtime`: Dynamic runtime values (statistics, cache)
+
+**Data Types:**
+- `string`: Text values
+- `integer`: Numeric values
+- `boolean`: True/false values (stored as "true"/"false")
+- `json`: JSON object/array values
+
+### 2. `config_history` Table
+
+```sql
+-- Configuration change history table
+CREATE TABLE config_history (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    config_key TEXT NOT NULL,               -- Key that was changed
+    old_value TEXT,                         -- Previous value (NULL for new keys)
+    new_value TEXT NOT NULL,                -- New value
+    changed_by TEXT DEFAULT 'system',       -- Who made the change (system/admin/user)
+    change_reason TEXT,                     -- Optional reason for change
+    changed_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),
+    FOREIGN KEY (config_key) REFERENCES server_config(key)
+);
+```
+
+### 3. `config_validation_log` Table
+
+```sql
+-- Configuration validation errors log
+CREATE TABLE config_validation_log (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    config_key TEXT NOT NULL,
+    attempted_value TEXT,
+    validation_error TEXT NOT NULL,
+    error_source TEXT DEFAULT 'validation',  -- validation/parsing/constraint
+    attempted_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now'))
+);
+```
+
+### 4. Configuration File Cache Table
+
+```sql
+-- Cache for file-based configuration events
+CREATE TABLE config_file_cache (
+    file_path TEXT PRIMARY KEY,             -- Full path to config file
+    file_hash TEXT NOT NULL,                -- SHA256 hash of file content
+    event_id TEXT,                          -- Nostr event ID from file
+    event_pubkey TEXT,                      -- Admin pubkey that signed event
+    loaded_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),
+    validation_status TEXT CHECK (validation_status IN ('valid', 'invalid', 'unverified')),
+    validation_error TEXT                   -- Error details if invalid
+);
+```
+
+## Indexes and Performance
+
+```sql
+-- Performance indexes for configuration tables
+CREATE INDEX idx_server_config_type ON server_config(config_type);
+CREATE INDEX idx_server_config_updated ON server_config(updated_at DESC);
+CREATE INDEX idx_config_history_key ON config_history(config_key);
+CREATE INDEX idx_config_history_time ON config_history(changed_at DESC);
+CREATE INDEX idx_config_validation_key ON config_validation_log(config_key);
+CREATE INDEX idx_config_validation_time ON config_validation_log(attempted_at DESC);
+```
+
+## Triggers
+
+### Update Timestamp Trigger
+
+```sql
+-- Trigger to update timestamp on configuration changes
+CREATE TRIGGER update_config_timestamp
+    AFTER UPDATE ON server_config
+BEGIN
+    UPDATE server_config SET updated_at = strftime('%s', 'now') WHERE key = NEW.key;
+END;
+```
+
+### Configuration History Trigger
+
+```sql
+-- Trigger to log configuration changes to history
+CREATE TRIGGER log_config_changes
+    AFTER UPDATE ON server_config
+    WHEN OLD.value != NEW.value
+BEGIN
+    INSERT INTO config_history (config_key, old_value, new_value, changed_by, change_reason)
+    VALUES (NEW.key, OLD.value, NEW.value, 'system', 'configuration update');
+END;
+```
+
+## Default Configuration Values
+
+### Core System Settings
+
+```sql
+INSERT OR IGNORE INTO server_config (key, value, description, config_type, data_type, requires_restart) VALUES
+-- Administrative settings
+('admin_pubkey', '', 'Authorized admin public key (hex)', 'system', 'string', 1),
+('admin_enabled', 'false', 'Enable admin interface', 'system', 'boolean', 1),
+
+-- Server core settings
+('relay_port', '8888', 'WebSocket server port', 'user', 'integer', 1),
+('database_path', 'db/c_nostr_relay.db', 'SQLite database file path', 'user', 'string', 1),
+('max_connections', '100', 'Maximum concurrent connections', 'user', 'integer', 1),
+
+-- NIP-11 Relay Information
+('relay_name', 'C Nostr Relay', 'Relay name for NIP-11', 'user', 'string', 0),
+('relay_description', 'High-performance C Nostr relay with SQLite storage', 'Relay description', 'user', 'string', 0),
+('relay_contact', '', 'Contact information', 'user', 'string', 0),
+('relay_pubkey', '', 'Relay public key', 'user', 'string', 0),
+('relay_software', 'https://git.laantungir.net/laantungir/c-relay.git', 'Software URL', 'user', 'string', 0),
+('relay_version', '0.2.0', 'Software version', 'user', 'string', 0),
+
+-- NIP-13 Proof of Work
+('pow_enabled', 'true', 'Enable NIP-13 Proof of Work validation', 'user', 'boolean', 0),
+('pow_min_difficulty', '0', 'Minimum PoW difficulty required', 'user', 'integer', 0),
+('pow_mode', 'basic', 'PoW validation mode (basic/full/strict)', 'user', 'string', 0),
+
+-- NIP-40 Expiration Timestamp
+('expiration_enabled', 'true', 'Enable NIP-40 expiration handling', 'user', 'boolean', 0),
+('expiration_strict', 'true', 'Reject expired events on submission', 'user', 'boolean', 0),
+('expiration_filter', 'true', 'Filter expired events from responses', 'user', 'boolean', 0),
+('expiration_grace_period', '300', 'Grace period for clock skew (seconds)', 'user', 'integer', 0),
+
+-- Subscription limits
+('max_subscriptions_per_client', '20', 'Max subscriptions per client', 'user', 'integer', 0),
+('max_total_subscriptions', '5000', 'Max total concurrent subscriptions', 'user', 'integer', 0),
+('subscription_id_max_length', '64', 'Maximum subscription ID length', 'user', 'integer', 0),
+
+-- Event processing limits
+('max_event_tags', '100', 'Maximum tags per event', 'user', 'integer', 0),
+('max_content_length', '8196', 'Maximum content length', 'user', 'integer', 0),
+('max_message_length', '16384', 'Maximum message length', 'user', 'integer', 0),
+
+-- Performance settings
+('default_limit', '500', 'Default query limit', 'user', 'integer', 0),
+('max_limit', '5000', 'Maximum query limit', 'user', 'integer', 0);
+```
+
+### Runtime Statistics
+
+```sql
+INSERT OR IGNORE INTO server_config (key, value, description, config_type, data_type) VALUES
+-- Runtime statistics (updated by server)
+('server_start_time', '0', 'Server startup timestamp', 'runtime', 'integer'),
+('total_events_processed', '0', 'Total events processed', 'runtime', 'integer'),
+('total_subscriptions_created', '0', 'Total subscriptions created', 'runtime', 'integer'),
+('current_connections', '0', 'Current active connections', 'runtime', 'integer'),
+('database_size_bytes', '0', 'Database file size in bytes', 'runtime', 'integer');
+```
+
+## Configuration Views
+
+### Active Configuration View
+
+```sql
+CREATE VIEW active_config AS
+SELECT 
+    key,
+    value,
+    description,
+    config_type,
+    data_type,
+    requires_restart,
+    updated_at
+FROM server_config
+WHERE config_type IN ('system', 'user')
+ORDER BY config_type, key;
+```
+
+### Runtime Statistics View
+
+```sql
+CREATE VIEW runtime_stats AS
+SELECT 
+    key,
+    value,
+    description,
+    updated_at
+FROM server_config
+WHERE config_type = 'runtime'
+ORDER BY key;
+```
+
+### Configuration Change Summary
+
+```sql
+CREATE VIEW recent_config_changes AS
+SELECT 
+    ch.config_key,
+    sc.description,
+    ch.old_value,
+    ch.new_value,
+    ch.changed_by,
+    ch.change_reason,
+    ch.changed_at
+FROM config_history ch
+JOIN server_config sc ON ch.config_key = sc.key
+ORDER BY ch.changed_at DESC
+LIMIT 50;
+```
+
+## Validation Rules Format
+
+Configuration validation rules are stored as JSON strings in the `validation_rules` column:
+
+```json
+{
+  "type": "integer",
+  "min": 1,
+  "max": 65535,
+  "required": true
+}
+```
+
+```json
+{
+  "type": "string",
+  "pattern": "^[0-9a-fA-F]{64}$",
+  "required": false,
+  "description": "64-character hex string"
+}
+```
+
+```json
+{
+  "type": "boolean",
+  "required": true
+}
+```
+
+## Migration Strategy
+
+1. **Phase 1**: Add configuration tables to existing schema
+2. **Phase 2**: Populate with current hardcoded values
+3. **Phase 3**: Update application code to read from database
+4. **Phase 4**: Add file-based configuration loading
+5. **Phase 5**: Remove hardcoded defaults and environment variable fallbacks
+
+## Integration Points
+
+- **Startup**: Load configuration from file → database → apply to application
+- **Runtime**: Read configuration values from database cache
+- **Updates**: Write changes to database → optionally update file
+- **Validation**: Validate all configuration changes before applying
+- **History**: Track all configuration changes for audit purposes

docs/file_config_design.md

@@ -0,0 +1,493 @@
+# File-Based Configuration Architecture Design
+
+## Overview
+This document outlines the XDG-compliant file-based configuration system for the C Nostr Relay, following the Ginxsom admin system approach using signed Nostr events.
+
+## XDG Base Directory Specification Compliance
+
+### File Location Strategy
+
+**Primary Location:**
+```
+$XDG_CONFIG_HOME/c-relay/c_relay_config_event.json
+```
+
+**Fallback Location:**
+```
+$HOME/.config/c-relay/c_relay_config_event.json
+```
+
+**System-wide Fallback:**
+```
+/etc/c-relay/c_relay_config_event.json
+```
+
+### Directory Structure
+```
+$XDG_CONFIG_HOME/c-relay/
+├── c_relay_config_event.json          # Main configuration file
+├── backup/                            # Configuration backups
+│   ├── c_relay_config_event.json.bak
+│   └── c_relay_config_event.20241205.json
+└── validation/                        # Validation logs
+    └── config_validation.log
+```
+
+## Configuration File Format
+
+### Signed Nostr Event Structure
+
+The configuration file contains a signed Nostr event (kind 33334) with relay configuration:
+
+```json
+{
+  "kind": 33334,
+  "created_at": 1704067200,
+  "tags": [
+    ["relay_name", "C Nostr Relay"],
+    ["relay_description", "High-performance C Nostr relay with SQLite storage"],
+    ["relay_port", "8888"],
+    ["database_path", "db/c_nostr_relay.db"],
+    ["admin_pubkey", ""],
+    ["admin_enabled", "false"],
+    
+    ["pow_enabled", "true"],
+    ["pow_min_difficulty", "0"],
+    ["pow_mode", "basic"],
+    
+    ["expiration_enabled", "true"],
+    ["expiration_strict", "true"],
+    ["expiration_filter", "true"],
+    ["expiration_grace_period", "300"],
+    
+    ["max_subscriptions_per_client", "20"],
+    ["max_total_subscriptions", "5000"],
+    ["max_connections", "100"],
+    
+    ["relay_contact", ""],
+    ["relay_pubkey", ""],
+    ["relay_software", "https://git.laantungir.net/laantungir/c-relay.git"],
+    ["relay_version", "0.2.0"],
+    
+    ["max_event_tags", "100"],
+    ["max_content_length", "8196"],
+    ["max_message_length", "16384"],
+    ["default_limit", "500"],
+    ["max_limit", "5000"]
+  ],
+  "content": "C Nostr Relay configuration event",
+  "pubkey": "admin_public_key_hex_64_chars",
+  "id": "computed_event_id_hex_64_chars",
+  "sig": "computed_signature_hex_128_chars"
+}
+```
+
+### Event Kind Definition
+
+**Kind 33334**: C Nostr Relay Configuration Event
+- Parameterized replaceable event
+- Must be signed by authorized admin pubkey
+- Contains relay configuration as tags
+- Validation required on load
+
+## Configuration Loading Architecture
+
+### Loading Priority Chain
+
+1. **Command Line Arguments** (highest priority)
+2. **File-based Configuration** (signed Nostr event)
+3. **Database Configuration** (persistent storage)
+4. **Environment Variables** (compatibility mode)
+5. **Hardcoded Defaults** (fallback)
+
+### Loading Process Flow
+
+```mermaid
+flowchart TD
+    A[Server Startup] --> B[Get Config File Path]
+    B --> C{File Exists?}
+    C -->|No| D[Check Database Config]
+    C -->|Yes| E[Load & Parse JSON]
+    E --> F[Validate Event Structure]
+    F --> G{Valid Event?}
+    G -->|No| H[Log Error & Use Database]
+    G -->|Yes| I[Verify Event Signature]
+    I --> J{Signature Valid?}
+    J -->|No| K[Log Error & Use Database]
+    J -->|Yes| L[Extract Configuration Tags]
+    L --> M[Apply to Database]
+    M --> N[Apply to Application]
+    D --> O[Load from Database]
+    H --> O
+    K --> O
+    O --> P[Apply Environment Variable Overrides]
+    P --> Q[Apply Command Line Overrides]
+    Q --> N
+    N --> R[Server Ready]
+```
+
+## C Implementation Architecture
+
+### Core Data Structures
+
+```c
+// Configuration file management
+typedef struct {
+    char file_path[512];
+    char file_hash[65];      // SHA256 hash
+    time_t last_modified;
+    time_t last_loaded;
+    int validation_status;   // 0=valid, 1=invalid, 2=unverified
+    char validation_error[256];
+} config_file_info_t;
+
+// Configuration event structure
+typedef struct {
+    char event_id[65];
+    char pubkey[65];
+    char signature[129];
+    long created_at;
+    int kind;
+    cJSON* tags;
+    char* content;
+} config_event_t;
+
+// Configuration management context
+typedef struct {
+    config_file_info_t file_info;
+    config_event_t event;
+    int loaded_from_file;
+    int loaded_from_database;
+    char admin_pubkey[65];
+    time_t load_timestamp;
+} config_context_t;
+```
+
+### Core Function Signatures
+
+```c
+// XDG path resolution
+int get_config_file_path(char* path, size_t path_size);
+int create_config_directories(const char* config_path);
+
+// File operations
+int load_config_from_file(const char* config_path, config_context_t* ctx);
+int save_config_to_file(const char* config_path, const config_event_t* event);
+int backup_config_file(const char* config_path);
+
+// Event validation
+int validate_config_event_structure(const cJSON* event);
+int verify_config_event_signature(const config_event_t* event, const char* admin_pubkey);
+int validate_config_tag_values(const cJSON* tags);
+
+// Configuration extraction and application
+int extract_config_from_tags(const cJSON* tags, config_context_t* ctx);
+int apply_config_to_database(const config_context_t* ctx);
+int apply_config_to_globals(const config_context_t* ctx);
+
+// File monitoring and updates
+int monitor_config_file_changes(const char* config_path);
+int reload_config_on_change(config_context_t* ctx);
+
+// Error handling and logging
+int log_config_validation_error(const char* config_key, const char* error);
+int log_config_load_event(const config_context_t* ctx, const char* source);
+```
+
+## Configuration Validation Rules
+
+### Event Structure Validation
+
+1. **Required Fields**: `kind`, `created_at`, `tags`, `content`, `pubkey`, `id`, `sig`
+2. **Kind Validation**: Must be exactly 33334
+3. **Timestamp Validation**: Must be reasonable (not too old, not future)
+4. **Tags Format**: Array of string arrays `[["key", "value"], ...]`
+5. **Signature Verification**: Must be signed by authorized admin pubkey
+
+### Configuration Value Validation
+
+```c
+typedef struct {
+    char* key;
+    char* data_type;        // "string", "integer", "boolean", "json"
+    char* validation_rule;  // JSON validation rule
+    int required;
+    char* default_value;
+} config_validation_rule_t;
+
+static config_validation_rule_t validation_rules[] = {
+    {"relay_port", "integer", "{\"min\": 1, \"max\": 65535}", 1, "8888"},
+    {"pow_min_difficulty", "integer", "{\"min\": 0, \"max\": 64}", 1, "0"},
+    {"expiration_grace_period", "integer", "{\"min\": 0, \"max\": 86400}", 1, "300"},
+    {"admin_pubkey", "string", "{\"pattern\": \"^[0-9a-fA-F]{64}$\"}", 0, ""},
+    {"pow_enabled", "boolean", "{}", 1, "true"},
+    // ... more rules
+};
+```
+
+### Security Validation
+
+1. **Admin Pubkey Verification**: Only configured admin pubkeys can create config events
+2. **Event ID Verification**: Event ID must match computed hash
+3. **Signature Verification**: Signature must be valid for the event and pubkey
+4. **Timestamp Validation**: Prevent replay attacks with old events
+5. **File Permission Checks**: Config files should have appropriate permissions
+
+## File Management Features
+
+### Configuration File Operations
+
+**File Creation:**
+- Generate initial configuration file with default values
+- Sign with admin private key
+- Set appropriate file permissions (600 - owner read/write only)
+
+**File Updates:**
+- Create backup of existing file
+- Validate new configuration
+- Atomic file replacement (write to temp, then rename)
+- Update file metadata cache
+
+**File Monitoring:**
+- Watch for file system changes using inotify (Linux)
+- Reload configuration automatically when file changes
+- Validate changes before applying
+- Log all configuration reload events
+
+### Backup and Recovery
+
+**Automatic Backups:**
+```
+$XDG_CONFIG_HOME/c-relay/backup/
+├── c_relay_config_event.json.bak           # Last working config
+├── c_relay_config_event.20241205-143022.json # Timestamped backups
+└── c_relay_config_event.20241204-091530.json
+```
+
+**Recovery Process:**
+1. Detect corrupted or invalid config file
+2. Attempt to load from `.bak` backup
+3. If backup fails, generate default configuration
+4. Log recovery actions for audit
+
+## Integration with Database Schema
+
+### File-Database Synchronization
+
+**On File Load:**
+1. Parse and validate file-based configuration
+2. Extract configuration values from event tags
+3. Update database `server_config` table
+4. Record file metadata in `config_file_cache` table
+5. Log configuration changes in `config_history` table
+
+**Configuration Priority Resolution:**
+```c
+char* get_config_value(const char* key, const char* default_value) {
+    // Priority: CLI args > File config > DB config > Env vars > Default
+    char* value = NULL;
+    
+    // 1. Check command line overrides (if implemented)
+    value = get_cli_override(key);
+    if (value) return value;
+    
+    // 2. Check database (updated from file)
+    value = get_database_config(key);
+    if (value) return value;
+    
+    // 3. Check environment variables (compatibility)
+    value = get_env_config(key);
+    if (value) return value;
+    
+    // 4. Return default
+    return strdup(default_value);
+}
+```
+
+## Error Handling and Recovery
+
+### Validation Error Handling
+
+```c
+typedef enum {
+    CONFIG_ERROR_NONE = 0,
+    CONFIG_ERROR_FILE_NOT_FOUND = 1,
+    CONFIG_ERROR_PARSE_FAILED = 2,
+    CONFIG_ERROR_INVALID_STRUCTURE = 3,
+    CONFIG_ERROR_SIGNATURE_INVALID = 4,
+    CONFIG_ERROR_UNAUTHORIZED = 5,
+    CONFIG_ERROR_VALUE_INVALID = 6,
+    CONFIG_ERROR_IO_ERROR = 7
+} config_error_t;
+
+typedef struct {
+    config_error_t error_code;
+    char error_message[256];
+    char config_key[64];
+    char invalid_value[128];
+    time_t error_timestamp;
+} config_error_info_t;
+```
+
+### Graceful Degradation
+
+**File Load Failure:**
+1. Log detailed error information
+2. Fall back to database configuration
+3. Continue operation with last known good config
+4. Set service status to "degraded" mode
+
+**Validation Failure:**
+1. Log validation errors with specific details
+2. Skip invalid configuration items
+3. Use default values for failed items
+4. Continue with partial configuration
+
+**Permission Errors:**
+1. Log permission issues
+2. Attempt to use fallback locations
+3. Generate temporary config if needed
+4. Alert administrator via logs
+
+## Configuration Update Process
+
+### Safe Configuration Updates
+
+**Atomic Update Process:**
+1. Create backup of current configuration
+2. Write new configuration to temporary file
+3. Validate new configuration completely
+4. If valid, rename temporary file to active config
+5. Update database with new values
+6. Apply changes to running server
+7. Log successful update
+
+**Rollback Process:**
+1. Detect invalid configuration at startup
+2. Restore from backup file
+3. Log rollback event
+4. Continue with previous working configuration
+
+### Hot Reload Support
+
+**File Change Detection:**
+```c
+int monitor_config_file_changes(const char* config_path) {
+    // Use inotify on Linux to watch file changes
+    int inotify_fd = inotify_init();
+    int watch_fd = inotify_add_watch(inotify_fd, config_path, IN_MODIFY | IN_MOVED_TO);
+    
+    // Monitor in separate thread
+    // On change: validate -> apply -> log
+    return 0;
+}
+```
+
+**Runtime Configuration Updates:**
+- Reload configuration on file change
+- Apply non-restart-required changes immediately
+- Queue restart-required changes for next restart
+- Notify operators of configuration changes
+
+## Security Considerations
+
+### Access Control
+
+**File Permissions:**
+- Config files: 600 (owner read/write only)
+- Directories: 700 (owner access only)
+- Backup files: 600 (owner read/write only)
+
+**Admin Key Management:**
+- Admin private keys never stored in config files
+- Only admin pubkeys stored for verification
+- Support for multiple admin pubkeys
+- Key rotation support
+
+### Signature Validation
+
+**Event Signature Verification:**
+```c
+int verify_config_event_signature(const config_event_t* event, const char* admin_pubkey) {
+    // 1. Reconstruct event for signing (without id and sig)
+    // 2. Compute event ID and verify against stored ID
+    // 3. Verify signature using admin pubkey
+    // 4. Check admin pubkey authorization
+    return NOSTR_SUCCESS;
+}
+```
+
+**Anti-Replay Protection:**
+- Configuration events must be newer than current
+- Event timestamps validated against reasonable bounds
+- Configuration history prevents replay attacks
+
+## Implementation Phases
+
+### Phase 1: Basic File Support
+- XDG path resolution
+- File loading and parsing
+- Basic validation
+- Database integration
+
+### Phase 2: Security Features
+- Event signature verification
+- Admin pubkey management
+- File permission checks
+- Error handling
+
+### Phase 3: Advanced Features
+- Hot reload support
+- Automatic backups
+- Configuration utilities
+- Interactive setup
+
+### Phase 4: Monitoring & Management
+- Configuration change monitoring
+- Advanced validation rules
+- Configuration audit logging
+- Management utilities
+
+## Configuration Generation Utilities
+
+### Interactive Setup Script
+
+```bash
+#!/bin/bash
+# scripts/setup_config.sh - Interactive configuration setup
+
+create_initial_config() {
+    echo "=== C Nostr Relay Initial Configuration ==="
+    
+    # Collect basic information
+    read -p "Relay name [C Nostr Relay]: " relay_name
+    read -p "Admin public key (hex): " admin_pubkey
+    read -p "Server port [8888]: " server_port
+    
+    # Generate signed configuration event
+    ./scripts/generate_config.sh \
+        --admin-key "$admin_pubkey" \
+        --relay-name "${relay_name:-C Nostr Relay}" \
+        --port "${server_port:-8888}" \
+        --output "$XDG_CONFIG_HOME/c-relay/c_relay_config_event.json"
+}
+```
+
+### Configuration Validation Utility
+
+```bash
+#!/bin/bash
+# scripts/validate_config.sh - Validate configuration file
+
+validate_config_file() {
+    local config_file="$1"
+    
+    # Check file exists and is readable
+    # Validate JSON structure
+    # Verify event signature
+    # Check configuration values
+    # Report validation results
+}
+```
+
+This comprehensive file-based configuration design provides a robust, secure, and maintainable system that follows industry standards while integrating seamlessly with the existing C Nostr Relay architecture.

make_and_restart_relay.sh

@@ -5,6 +5,71 @@
 
 echo "=== C Nostr Relay Build and Restart Script ==="
 
+# Parse command line arguments
+PRESERVE_CONFIG=false
+HELP=false
+
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --preserve-config|-p)
+            PRESERVE_CONFIG=true
+            shift
+            ;;
+        --help|-h)
+            HELP=true
+            shift
+            ;;
+        *)
+            echo "Unknown option: $1"
+            HELP=true
+            shift
+            ;;
+    esac
+done
+
+# Show help
+if [ "$HELP" = true ]; then
+    echo "Usage: $0 [OPTIONS]"
+    echo ""
+    echo "Options:"
+    echo "  --preserve-config, -p  Keep existing configuration file (don't regenerate)"
+    echo "  --help, -h         Show this help message"
+    echo ""
+    echo "Development Setup:"
+    echo "  Uses local config directory: ./dev-config/"
+    echo "  This avoids conflicts with production instances using ~/.config/c-relay/"
+    echo ""
+    echo "Default behavior: Automatically regenerates configuration file on each build"
+    echo "                 for development purposes"
+    exit 0
+fi
+
+# Handle configuration file and database regeneration
+# Use local development config directory to avoid conflicts with production
+DEV_CONFIG_DIR="./dev-config"
+CONFIG_FILE="$DEV_CONFIG_DIR/c_relay_config_event.json"
+DB_FILE="./db/c_nostr_relay.db"
+
+# Create development config directory if it doesn't exist
+mkdir -p "$DEV_CONFIG_DIR"
+
+if [ "$PRESERVE_CONFIG" = false ]; then
+    if [ -f "$CONFIG_FILE" ]; then
+        echo "Removing old development configuration file to trigger regeneration..."
+        rm -f "$CONFIG_FILE"
+        echo "✓ Development configuration file removed - will be regenerated with new keys"
+    fi
+    if [ -f "$DB_FILE" ]; then
+        echo "Removing old database to trigger fresh key generation..."
+        rm -f "$DB_FILE"*  # Remove db file and any WAL/SHM files
+        echo "✓ Database removed - will be recreated with embedded schema and new keys"
+    fi
+elif [ "$PRESERVE_CONFIG" = true ]; then
+    echo "Preserving existing development configuration and database as requested"
+else
+    echo "No existing development configuration or database found - will generate fresh setup"
+fi
+
 # Build the project first
 echo "Building project..."
 make clean all
@@ -60,18 +125,16 @@ fi
 # Clean up PID file
 rm -f relay.pid
 
-# Initialize database if needed
-if [ ! -f "./db/c_nostr_relay.db" ]; then
-    echo "Initializing database..."
-    ./db/init.sh --force >/dev/null 2>&1
-fi
+# Database initialization is now handled automatically by the relay
+# when it starts up with embedded schema
+echo "Database will be initialized automatically on startup if needed"
 
 # Start relay in background with output redirection
 echo "Starting relay server..."
 echo "Debug: Current processes: $(ps aux | grep 'c_relay_' | grep -v grep || echo 'None')"
 
-# Start relay in background and capture its PID
-$BINARY_PATH > relay.log 2>&1 &
+# Start relay in background and capture its PID with development config directory
+$BINARY_PATH --config-dir "$DEV_CONFIG_DIR" > relay.log 2>&1 &
 RELAY_PID=$!
 
 echo "Started with PID: $RELAY_PID"
@@ -90,11 +153,25 @@ if ps -p "$RELAY_PID" >/dev/null 2>&1; then
     # Save PID for debugging
     echo $RELAY_PID > relay.pid
 
+    # Check if new keys were generated and display them
+    sleep 1  # Give relay time to write initial logs
+    if grep -q "GENERATED RELAY KEYPAIRS" relay.log 2>/dev/null; then
+        echo "=== IMPORTANT: NEW KEYPAIRS GENERATED ==="
+        echo ""
+        # Extract and display the keypairs section from the log
+        grep -A 12 -B 2 "GENERATED RELAY KEYPAIRS" relay.log | head -n 16
+        echo ""
+        echo "⚠️  SAVE THESE PRIVATE KEYS SECURELY - THEY CONTROL YOUR RELAY!"
+        echo "⚠️  These keys are also logged in relay.log for reference"
+        echo ""
+    fi
+
     echo "=== Relay server running in background ==="
+    echo "Development config: $DEV_CONFIG_DIR/"
     echo "To kill relay: pkill -f 'c_relay_'"
     echo "To check status: ps aux | grep c_relay_"
     echo "To view logs: tail -f relay.log"
-    echo "Binary: $BINARY_PATH"
+    echo "Binary: $BINARY_PATH --config-dir $DEV_CONFIG_DIR"
     echo "Ready for Nostr client connections!"
 else
     echo "ERROR: Relay failed to start"

relay.log

@@ -1,117 +0,0 @@
-=== C Nostr Relay Server ===
-[SUCCESS] Database connection established
-[SUCCESS] Relay information initialized with default values
-[INFO] Initializing NIP-13 Proof of Work configuration
-[INFO] PoW Configuration: enabled=true, min_difficulty=0, validation_flags=0x1, mode=full
-[INFO] Starting relay server...
-[INFO] Starting libwebsockets-based Nostr relay server...
-[SUCCESS] WebSocket relay started on ws://127.0.0.1:8888
-[INFO] HTTP request received
-[INFO] Handling NIP-11 relay information request
-[SUCCESS] NIP-11 relay information served successfully
-[INFO] HTTP request received
-[INFO] Handling NIP-11 relay information request
-[SUCCESS] NIP-11 relay information served successfully
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[SUCCESS] Event stored in database
-[SUCCESS] Event validated and stored successfully
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[INFO] PoW validated: difficulty=10, target=8, nonce=1839
-[SUCCESS] Event stored in database
-[SUCCESS] Event validated and stored successfully
-[INFO] WebSocket connection closed
-[INFO] HTTP request received
-[INFO] Handling NIP-11 relay information request
-[SUCCESS] NIP-11 relay information served successfully
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[INFO] PoW validated: difficulty=21, target=20, nonce=776797
-[SUCCESS] Event stored in database
-[SUCCESS] Event validated and stored successfully
-[INFO] WebSocket connection closed
-[INFO] HTTP request received
-[INFO] Handling NIP-11 relay information request
-[SUCCESS] NIP-11 relay information served successfully
-[INFO] HTTP request received
-[INFO] Handling NIP-11 relay information request
-[SUCCESS] NIP-11 relay information served successfully
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[SUCCESS] Event stored in database
-[SUCCESS] Event validated and stored successfully
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[INFO] PoW validated: difficulty=8, target=8, nonce=385
-[SUCCESS] Event stored in database
-[SUCCESS] Event validated and stored successfully
-[INFO] WebSocket connection closed
-[INFO] HTTP request received
-[INFO] Handling NIP-11 relay information request
-[SUCCESS] NIP-11 relay information served successfully
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] Received WebSocket message
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[INFO] PoW validated: difficulty=21, target=20, nonce=776797
-[WARNING] Event already exists in database
-[SUCCESS] Event validated and stored successfully
-[INFO] WebSocket connection closed
-[INFO] HTTP request received
-[INFO] Handling NIP-11 relay information request
-[SUCCESS] NIP-11 relay information served successfully
-[INFO] HTTP request received
-[INFO] Handling NIP-11 relay information request
-[SUCCESS] NIP-11 relay information served successfully
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[SUCCESS] Event stored in database
-[SUCCESS] Event validated and stored successfully
-[INFO] WebSocket connection closed
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[INFO] PoW validated: difficulty=8, target=8, nonce=1669
-[SUCCESS] Event stored in database
-[SUCCESS] Event validated and stored successfully
-[INFO] WebSocket connection closed
-[INFO] HTTP request received
-[INFO] Handling NIP-11 relay information request
-[SUCCESS] NIP-11 relay information served successfully
-[INFO] WebSocket connection established
-[INFO] Received WebSocket message
-[INFO] Handling EVENT message with full NIP-01 validation
-[INFO] PoW validated: difficulty=21, target=20, nonce=776797
-[WARNING] Event already exists in database
-[SUCCESS] Event validated and stored successfully
-[INFO] WebSocket connection closed

relay.pid

@@ -1 +1 @@
-736301
+960728

src/config.h

@@ -0,0 +1,232 @@
+#ifndef CONFIG_H
+#define CONFIG_H
+
+#include <sqlite3.h>
+#include <time.h>
+#include <stddef.h>
+#include <cjson/cJSON.h>
+
+// Configuration system constants
+#define CONFIG_KEY_MAX_LENGTH 64
+#define CONFIG_VALUE_MAX_LENGTH 512
+#define CONFIG_DESCRIPTION_MAX_LENGTH 256
+#define CONFIG_XDG_DIR_NAME "c-relay"
+#define CONFIG_FILE_NAME "c_relay_config_event.json"
+#define CONFIG_ADMIN_PRIVKEY_ENV "C_RELAY_ADMIN_PRIVKEY"
+#define CONFIG_RELAY_PRIVKEY_ENV "C_RELAY_PRIVKEY"
+#define CONFIG_DIR_OVERRIDE_ENV "C_RELAY_CONFIG_DIR_OVERRIDE"
+#define CONFIG_FILE_OVERRIDE_ENV "C_RELAY_CONFIG_FILE_OVERRIDE"
+#define NOSTR_PUBKEY_HEX_LENGTH 64
+#define NOSTR_PRIVKEY_HEX_LENGTH 64
+#define NOSTR_EVENT_ID_HEX_LENGTH 64
+#define NOSTR_SIGNATURE_HEX_LENGTH 128
+
+// Protocol and implementation constants (hardcoded - should NOT be configurable)
+#define SUBSCRIPTION_ID_MAX_LENGTH 64
+#define CLIENT_IP_MAX_LENGTH 64
+#define RELAY_NAME_MAX_LENGTH 128
+#define RELAY_DESCRIPTION_MAX_LENGTH 1024
+#define RELAY_URL_MAX_LENGTH 256
+#define RELAY_CONTACT_MAX_LENGTH 128
+#define RELAY_PUBKEY_MAX_LENGTH 65
+
+// Default configuration values (used as fallbacks if database config fails)
+#define DEFAULT_DATABASE_PATH "db/c_nostr_relay.db"
+#define DEFAULT_PORT 8888
+#define DEFAULT_HOST "127.0.0.1"
+#define MAX_CLIENTS 100
+#define MAX_SUBSCRIPTIONS_PER_CLIENT 20
+#define MAX_TOTAL_SUBSCRIPTIONS 5000
+#define MAX_FILTERS_PER_SUBSCRIPTION 10
+
+// Configuration types
+typedef enum {
+    CONFIG_TYPE_SYSTEM = 0,
+    CONFIG_TYPE_USER = 1,
+    CONFIG_TYPE_RUNTIME = 2
+} config_type_t;
+
+// Configuration data types
+typedef enum {
+    CONFIG_DATA_STRING = 0,
+    CONFIG_DATA_INTEGER = 1,
+    CONFIG_DATA_BOOLEAN = 2,
+    CONFIG_DATA_JSON = 3
+} config_data_type_t;
+
+// Configuration validation result
+typedef enum {
+    CONFIG_VALID = 0,
+    CONFIG_INVALID_TYPE = 1,
+    CONFIG_INVALID_RANGE = 2,
+    CONFIG_INVALID_FORMAT = 3,
+    CONFIG_MISSING_REQUIRED = 4
+} config_validation_result_t;
+
+// Configuration entry structure
+typedef struct {
+    char key[CONFIG_KEY_MAX_LENGTH];
+    char value[CONFIG_VALUE_MAX_LENGTH];
+    char description[CONFIG_DESCRIPTION_MAX_LENGTH];
+    config_type_t config_type;
+    config_data_type_t data_type;
+    int is_sensitive;
+    int requires_restart;
+    time_t created_at;
+    time_t updated_at;
+} config_entry_t;
+
+// Configuration manager state
+typedef struct {
+    sqlite3* db;
+    sqlite3_stmt* get_config_stmt;
+    sqlite3_stmt* set_config_stmt;
+    sqlite3_stmt* log_change_stmt;
+    
+    // Configuration loading status
+    int file_config_loaded;
+    int database_config_loaded;
+    time_t last_reload;
+    
+    // XDG configuration directory
+    char config_dir_path[512];
+    char config_file_path[600];
+} config_manager_t;
+
+// Global configuration manager instance
+extern config_manager_t g_config_manager;
+
+// ================================
+// CORE CONFIGURATION FUNCTIONS
+// ================================
+
+// Initialize configuration system
+int init_configuration_system(void);
+
+// Cleanup configuration system
+void cleanup_configuration_system(void);
+
+// Load configuration from all sources (file -> database -> defaults)
+int load_configuration(void);
+
+// Apply loaded configuration to global variables
+int apply_configuration_to_globals(void);
+
+// ================================
+// DATABASE CONFIGURATION FUNCTIONS
+// ================================
+
+// Initialize database prepared statements
+int init_config_database_statements(void);
+
+// Get configuration value from database
+int get_database_config(const char* key, char* value, size_t value_size);
+
+// Set configuration value in database
+int set_database_config(const char* key, const char* new_value, const char* changed_by);
+
+// Load all configuration from database
+int load_config_from_database(void);
+
+// ================================
+// FILE CONFIGURATION FUNCTIONS
+// ================================
+
+// Get XDG configuration directory path
+int get_xdg_config_dir(char* path, size_t path_size);
+
+// Check if configuration file exists
+int config_file_exists(void);
+
+// Load configuration from file
+int load_config_from_file(void);
+
+// Validate and apply Nostr configuration event
+int validate_and_apply_config_event(const cJSON* event);
+
+// Validate Nostr event structure
+int validate_nostr_event_structure(const cJSON* event);
+
+// Validate configuration tags array
+int validate_config_tags(const cJSON* tags);
+
+// Extract and apply configuration tags to database
+int extract_and_apply_config_tags(const cJSON* tags);
+
+// ================================
+// CONFIGURATION ACCESS FUNCTIONS
+// ================================
+
+// Get configuration value (checks all sources: file -> database -> environment -> defaults)
+const char* get_config_value(const char* key);
+
+// Get configuration value as integer
+int get_config_int(const char* key, int default_value);
+
+// Get configuration value as boolean
+int get_config_bool(const char* key, int default_value);
+
+// Set configuration value (updates database)
+int set_config_value(const char* key, const char* value);
+
+// ================================
+// CONFIGURATION VALIDATION
+// ================================
+
+// Validate configuration value
+config_validation_result_t validate_config_value(const char* key, const char* value);
+
+// Log validation error
+void log_config_validation_error(const char* key, const char* value, const char* error);
+
+// ================================
+// UTILITY FUNCTIONS
+// ================================
+
+// Convert config type enum to string
+const char* config_type_to_string(config_type_t type);
+
+// Convert config data type enum to string
+const char* config_data_type_to_string(config_data_type_t type);
+
+// Convert string to config type enum
+config_type_t string_to_config_type(const char* str);
+
+// Convert string to config data type enum
+config_data_type_t string_to_config_data_type(const char* str);
+
+// Check if configuration key requires restart
+int config_requires_restart(const char* key);
+
+// ================================
+// NOSTR EVENT GENERATION FUNCTIONS
+// ================================
+
+// Generate configuration file with valid Nostr event if it doesn't exist
+int generate_config_file_if_missing(void);
+
+// Create a valid Nostr configuration event from database values
+cJSON* create_config_nostr_event(const char* privkey_hex);
+
+// Generate a random private key (32 bytes as hex string)
+int generate_random_privkey(char* privkey_hex, size_t buffer_size);
+
+// Derive public key from private key (using secp256k1)
+int derive_pubkey_from_privkey(const char* privkey_hex, char* pubkey_hex, size_t buffer_size);
+
+// Create Nostr event ID (SHA256 of serialized event data)
+int create_nostr_event_id(const cJSON* event, char* event_id_hex, size_t buffer_size);
+
+// Sign Nostr event (using secp256k1 Schnorr signature)
+int sign_nostr_event(const cJSON* event, const char* privkey_hex, char* signature_hex, size_t buffer_size);
+
+// Write configuration event to file
+int write_config_event_to_file(const cJSON* event);
+
+// Helper function to generate random private key
+int generate_random_private_key(char* privkey_hex, size_t buffer_size);
+
+// Helper function to derive public key from private key
+int derive_public_key(const char* privkey_hex, char* pubkey_hex, size_t buffer_size);
+
+#endif // CONFIG_H

src/main.c

@@ -15,26 +15,8 @@
 #include "../nostr_core_lib/cjson/cJSON.h"
 #include "../nostr_core_lib/nostr_core/nostr_core.h"
 #include "../nostr_core_lib/nostr_core/nip013.h"  // NIP-13: Proof of Work
-
-// Server Configuration
-#define DEFAULT_PORT 8888
-#define DEFAULT_HOST "127.0.0.1"
-#define DATABASE_PATH "db/c_nostr_relay.db"
-#define MAX_CLIENTS 100
-
-// Persistent subscription system configuration
-#define MAX_SUBSCRIPTIONS_PER_CLIENT 20
-#define MAX_TOTAL_SUBSCRIPTIONS 5000
-#define MAX_FILTERS_PER_SUBSCRIPTION 10
-#define SUBSCRIPTION_ID_MAX_LENGTH 64
-#define CLIENT_IP_MAX_LENGTH 64
-
-// NIP-11 relay information configuration
-#define RELAY_NAME_MAX_LENGTH 128
-#define RELAY_DESCRIPTION_MAX_LENGTH 1024
-#define RELAY_URL_MAX_LENGTH 256
-#define RELAY_CONTACT_MAX_LENGTH 128
-#define RELAY_PUBKEY_MAX_LENGTH 65  // 64 hex chars + null terminator
+#include "config.h"  // Configuration management system
+#include "sql_schema.h"  // Embedded database schema
 
 // Color constants for logging
 #define RED     "\033[31m"
@@ -45,7 +27,7 @@
 #define RESET   "\033[0m"
 
 // Global state
-static sqlite3* g_db = NULL;
+sqlite3* g_db = NULL;  // Non-static so config.c can access it
 static int g_server_running = 1;
 static struct lws_context *ws_context = NULL;
 
@@ -97,6 +79,24 @@ static struct pow_config g_pow_config = {
     .anti_spam_mode = 0            // Basic validation by default
 };
 
+// NIP-40 Expiration configuration structure
+struct expiration_config {
+    int enabled;                    // 0 = disabled, 1 = enabled
+    int strict_mode;                // 1 = reject expired events on submission
+    int filter_responses;           // 1 = filter expired events from responses
+    int delete_expired;             // 1 = delete expired events from DB (future feature)
+    long grace_period;              // Grace period in seconds for clock skew
+};
+
+// Global expiration configuration instance
+static struct expiration_config g_expiration_config = {
+    .enabled = 1,                   // Enable expiration handling by default
+    .strict_mode = 1,               // Reject expired events on submission by default
+    .filter_responses = 1,          // Filter expired events from responses by default
+    .delete_expired = 0,            // Don't delete by default (keep for audit)
+    .grace_period = 300             // 5 minutes grace period for clock skew
+};
+
 
 /////////////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////////////////
@@ -170,8 +170,8 @@ static subscription_manager_t g_subscription_manager = {
     .active_subscriptions = NULL,
     .subscriptions_lock = PTHREAD_MUTEX_INITIALIZER,
     .total_subscriptions = 0,
-    .max_subscriptions_per_client = MAX_SUBSCRIPTIONS_PER_CLIENT,
-    .max_total_subscriptions = MAX_TOTAL_SUBSCRIPTIONS,
+    .max_subscriptions_per_client = MAX_SUBSCRIPTIONS_PER_CLIENT, // Will be updated from config
+    .max_total_subscriptions = MAX_TOTAL_SUBSCRIPTIONS, // Will be updated from config
     .total_created = 0,
     .total_events_broadcast = 0
 };
@@ -182,6 +182,9 @@ void log_success(const char* message);
 void log_error(const char* message);
 void log_warning(const char* message);
 
+// Forward declaration for subscription manager configuration
+void update_subscription_manager_config(void);
+
 // Forward declarations for subscription database logging
 void log_subscription_created(const subscription_t* sub);
 void log_subscription_closed(const char* sub_id, const char* client_ip, const char* reason);
@@ -217,6 +220,12 @@ int handle_nip11_http_request(struct lws* wsi, const char* accept_header);
 void init_pow_config();
 int validate_event_pow(cJSON* event, char* error_message, size_t error_size);
 
+// Forward declarations for NIP-40 expiration handling
+void init_expiration_config();
+long extract_expiration_timestamp(cJSON* tags);
+int is_event_expired(cJSON* event, time_t current_time);
+int validate_event_expiration(cJSON* event, char* error_message, size_t error_size);
+
 
 /////////////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////////////////
@@ -651,6 +660,19 @@ int broadcast_event_to_subscriptions(cJSON* event) {
         return 0;
     }
     
+    // Check if event is expired and should not be broadcast (NIP-40)
+    if (g_expiration_config.enabled && g_expiration_config.filter_responses) {
+        time_t current_time = time(NULL);
+        if (is_event_expired(event, current_time)) {
+            char debug_msg[256];
+            cJSON* event_id_obj = cJSON_GetObjectItem(event, "id");
+            const char* event_id = event_id_obj ? cJSON_GetStringValue(event_id_obj) : "unknown";
+            snprintf(debug_msg, sizeof(debug_msg), "Skipping broadcast of expired event: %.16s", event_id);
+            log_info(debug_msg);
+            return 0; // Don't broadcast expired events
+        }
+    }
+    
     int broadcasts = 0;
     
     pthread_mutex_lock(&g_subscription_manager.subscriptions_lock);
@@ -918,6 +940,19 @@ void log_warning(const char* message) {
     fflush(stdout);
 }
 
+// Update subscription manager configuration from config system
+void update_subscription_manager_config(void) {
+    g_subscription_manager.max_subscriptions_per_client = get_config_int("max_subscriptions_per_client", MAX_SUBSCRIPTIONS_PER_CLIENT);
+    g_subscription_manager.max_total_subscriptions = get_config_int("max_total_subscriptions", MAX_TOTAL_SUBSCRIPTIONS);
+    
+    char config_msg[256];
+    snprintf(config_msg, sizeof(config_msg),
+             "Subscription limits: max_per_client=%d, max_total=%d",
+             g_subscription_manager.max_subscriptions_per_client,
+             g_subscription_manager.max_total_subscriptions);
+    log_info(config_msg);
+}
+
 // Signal handler for graceful shutdown
 void signal_handler(int sig) {
     if (sig == SIGINT || sig == SIGTERM) {
@@ -1251,13 +1286,47 @@ int mark_event_as_deleted(const char* event_id, const char* deletion_event_id, c
 /////////////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////////////////
 
-// Initialize relay information with default values
+// Initialize relay information using configuration system
 void init_relay_info() {
-    // Set default relay information
-    strncpy(g_relay_info.name, "C Nostr Relay", sizeof(g_relay_info.name) - 1);
-    strncpy(g_relay_info.description, "A high-performance Nostr relay implemented in C with SQLite storage", sizeof(g_relay_info.description) - 1);
-    strncpy(g_relay_info.software, "https://github.com/teknari/c-relay", sizeof(g_relay_info.software) - 1);
-    strncpy(g_relay_info.version, "0.1.0", sizeof(g_relay_info.version) - 1);
+    // Load relay information from configuration system
+    const char* relay_name = get_config_value("relay_name");
+    if (relay_name) {
+        strncpy(g_relay_info.name, relay_name, sizeof(g_relay_info.name) - 1);
+    } else {
+        strncpy(g_relay_info.name, "C Nostr Relay", sizeof(g_relay_info.name) - 1);
+    }
+    
+    const char* relay_description = get_config_value("relay_description");
+    if (relay_description) {
+        strncpy(g_relay_info.description, relay_description, sizeof(g_relay_info.description) - 1);
+    } else {
+        strncpy(g_relay_info.description, "A high-performance Nostr relay implemented in C with SQLite storage", sizeof(g_relay_info.description) - 1);
+    }
+    
+    const char* relay_software = get_config_value("relay_software");
+    if (relay_software) {
+        strncpy(g_relay_info.software, relay_software, sizeof(g_relay_info.software) - 1);
+    } else {
+        strncpy(g_relay_info.software, "https://git.laantungir.net/laantungir/c-relay.git", sizeof(g_relay_info.software) - 1);
+    }
+    
+    const char* relay_version = get_config_value("relay_version");
+    if (relay_version) {
+        strncpy(g_relay_info.version, relay_version, sizeof(g_relay_info.version) - 1);
+    } else {
+        strncpy(g_relay_info.version, "0.2.0", sizeof(g_relay_info.version) - 1);
+    }
+    
+    // Load optional fields
+    const char* relay_contact = get_config_value("relay_contact");
+    if (relay_contact) {
+        strncpy(g_relay_info.contact, relay_contact, sizeof(g_relay_info.contact) - 1);
+    }
+    
+    const char* relay_pubkey = get_config_value("relay_pubkey");
+    if (relay_pubkey) {
+        strncpy(g_relay_info.pubkey, relay_pubkey, sizeof(g_relay_info.pubkey) - 1);
+    }
     
     // Initialize supported NIPs array
     g_relay_info.supported_nips = cJSON_CreateArray();
@@ -1268,24 +1337,25 @@ void init_relay_info() {
         cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(13));  // NIP-13: Proof of Work
         cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(15));  // NIP-15: EOSE
         cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(20));  // NIP-20: Command results
+        cJSON_AddItemToArray(g_relay_info.supported_nips, cJSON_CreateNumber(40));  // NIP-40: Expiration Timestamp
     }
     
-    // Initialize server limitations
+    // Initialize server limitations using configuration
     g_relay_info.limitation = cJSON_CreateObject();
     if (g_relay_info.limitation) {
-        cJSON_AddNumberToObject(g_relay_info.limitation, "max_message_length", 16384);
-        cJSON_AddNumberToObject(g_relay_info.limitation, "max_subscriptions", MAX_SUBSCRIPTIONS_PER_CLIENT);
-        cJSON_AddNumberToObject(g_relay_info.limitation, "max_limit", 5000);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_message_length", get_config_int("max_message_length", 16384));
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_subscriptions", get_config_int("max_subscriptions_per_client", 20));
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_limit", get_config_int("max_limit", 5000));
         cJSON_AddNumberToObject(g_relay_info.limitation, "max_subid_length", SUBSCRIPTION_ID_MAX_LENGTH);
-        cJSON_AddNumberToObject(g_relay_info.limitation, "max_event_tags", 100);
-        cJSON_AddNumberToObject(g_relay_info.limitation, "max_content_length", 8196);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_event_tags", get_config_int("max_event_tags", 100));
+        cJSON_AddNumberToObject(g_relay_info.limitation, "max_content_length", get_config_int("max_content_length", 8196));
         cJSON_AddNumberToObject(g_relay_info.limitation, "min_pow_difficulty", g_pow_config.min_pow_difficulty);
-        cJSON_AddBoolToObject(g_relay_info.limitation, "auth_required", cJSON_False);
+        cJSON_AddBoolToObject(g_relay_info.limitation, "auth_required", get_config_bool("admin_enabled", 0) ? cJSON_True : cJSON_False);
         cJSON_AddBoolToObject(g_relay_info.limitation, "payment_required", cJSON_False);
         cJSON_AddBoolToObject(g_relay_info.limitation, "restricted_writes", cJSON_False);
         cJSON_AddNumberToObject(g_relay_info.limitation, "created_at_lower_limit", 0);
         cJSON_AddNumberToObject(g_relay_info.limitation, "created_at_upper_limit", 2147483647);
-        cJSON_AddNumberToObject(g_relay_info.limitation, "default_limit", 500);
+        cJSON_AddNumberToObject(g_relay_info.limitation, "default_limit", get_config_int("default_limit", 500));
     }
     
     // Initialize empty retention policies (can be configured later)
@@ -1598,48 +1668,39 @@ int handle_nip11_http_request(struct lws* wsi, const char* accept_header) {
 /////////////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////////////////
 
-// Initialize PoW configuration with environment variables and defaults
+// Initialize PoW configuration using configuration system
 void init_pow_config() {
     log_info("Initializing NIP-13 Proof of Work configuration");
     
-    // Initialize with defaults (already set in struct initialization)
+    // Load PoW settings from configuration system
+    g_pow_config.enabled = get_config_bool("pow_enabled", 1);
+    g_pow_config.min_pow_difficulty = get_config_int("pow_min_difficulty", 0);
     
-    // Check environment variables for configuration
-    const char* pow_enabled_env = getenv("RELAY_POW_ENABLED");
-    if (pow_enabled_env) {
-        g_pow_config.enabled = (strcmp(pow_enabled_env, "1") == 0 ||
-                               strcmp(pow_enabled_env, "true") == 0 ||
-                               strcmp(pow_enabled_env, "yes") == 0);
-    }
-    
-    const char* min_diff_env = getenv("RELAY_MIN_POW_DIFFICULTY");
-    if (min_diff_env) {
-        int min_diff = atoi(min_diff_env);
-        if (min_diff >= 0 && min_diff <= 64) {  // Reasonable bounds
-            g_pow_config.min_pow_difficulty = min_diff;
-        }
-    }
-    
-    const char* pow_mode_env = getenv("RELAY_POW_MODE");
-    if (pow_mode_env) {
-        if (strcmp(pow_mode_env, "strict") == 0) {
+    // Get PoW mode from configuration
+    const char* pow_mode = get_config_value("pow_mode");
+    if (pow_mode) {
+        if (strcmp(pow_mode, "strict") == 0) {
             g_pow_config.validation_flags = NOSTR_POW_VALIDATE_ANTI_SPAM | NOSTR_POW_STRICT_FORMAT;
             g_pow_config.require_nonce_tag = 1;
             g_pow_config.reject_lower_targets = 1;
             g_pow_config.strict_format = 1;
             g_pow_config.anti_spam_mode = 1;
             log_info("PoW configured in strict anti-spam mode");
-        } else if (strcmp(pow_mode_env, "full") == 0) {
+        } else if (strcmp(pow_mode, "full") == 0) {
             g_pow_config.validation_flags = NOSTR_POW_VALIDATE_FULL;
             g_pow_config.require_nonce_tag = 1;
             log_info("PoW configured in full validation mode");
-        } else if (strcmp(pow_mode_env, "basic") == 0) {
+        } else if (strcmp(pow_mode, "basic") == 0) {
             g_pow_config.validation_flags = NOSTR_POW_VALIDATE_BASIC;
             log_info("PoW configured in basic validation mode");
-        } else if (strcmp(pow_mode_env, "disabled") == 0) {
+        } else if (strcmp(pow_mode, "disabled") == 0) {
             g_pow_config.enabled = 0;
-            log_info("PoW validation disabled via RELAY_POW_MODE");
+            log_info("PoW validation disabled via configuration");
         }
+    } else {
+        // Default to basic mode
+        g_pow_config.validation_flags = NOSTR_POW_VALIDATE_BASIC;
+        log_info("PoW configured in basic validation mode (default)");
     }
     
     // Log final configuration
@@ -1757,21 +1818,209 @@ int validate_event_pow(cJSON* event, char* error_message, size_t error_size) {
     return 0;  // Success
 }
 
+/////////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+//             NIP-40 EXPIRATION TIMESTAMP HANDLING
+/////////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+
+// Initialize expiration configuration using configuration system
+void init_expiration_config() {
+    log_info("Initializing NIP-40 Expiration Timestamp configuration");
+    
+    // Load expiration settings from configuration system
+    g_expiration_config.enabled = get_config_bool("expiration_enabled", 1);
+    g_expiration_config.strict_mode = get_config_bool("expiration_strict", 1);
+    g_expiration_config.filter_responses = get_config_bool("expiration_filter", 1);
+    g_expiration_config.delete_expired = get_config_bool("expiration_delete", 0);
+    g_expiration_config.grace_period = get_config_int("expiration_grace_period", 300);
+    
+    // Validate grace period bounds
+    if (g_expiration_config.grace_period < 0 || g_expiration_config.grace_period > 86400) {
+        log_warning("Invalid grace period, using default of 300 seconds");
+        g_expiration_config.grace_period = 300;
+    }
+    
+    // Log final configuration
+    char config_msg[512];
+    snprintf(config_msg, sizeof(config_msg),
+             "Expiration Configuration: enabled=%s, strict_mode=%s, filter_responses=%s, grace_period=%ld seconds",
+             g_expiration_config.enabled ? "true" : "false",
+             g_expiration_config.strict_mode ? "true" : "false",
+             g_expiration_config.filter_responses ? "true" : "false",
+             g_expiration_config.grace_period);
+    log_info(config_msg);
+}
+
+// Extract expiration timestamp from event tags
+long extract_expiration_timestamp(cJSON* tags) {
+    if (!tags || !cJSON_IsArray(tags)) {
+        return 0; // No expiration
+    }
+    
+    cJSON* tag = NULL;
+    cJSON_ArrayForEach(tag, tags) {
+        if (cJSON_IsArray(tag) && cJSON_GetArraySize(tag) >= 2) {
+            cJSON* tag_name = cJSON_GetArrayItem(tag, 0);
+            cJSON* tag_value = cJSON_GetArrayItem(tag, 1);
+            
+            if (cJSON_IsString(tag_name) && cJSON_IsString(tag_value)) {
+                const char* name = cJSON_GetStringValue(tag_name);
+                const char* value = cJSON_GetStringValue(tag_value);
+                
+                if (name && value && strcmp(name, "expiration") == 0) {
+                    long expiration_ts = atol(value);
+                    if (expiration_ts > 0) {
+                        return expiration_ts;
+                    }
+                }
+            }
+        }
+    }
+    
+    return 0; // No valid expiration tag found
+}
+
+// Check if event is currently expired
+int is_event_expired(cJSON* event, time_t current_time) {
+    if (!event) {
+        return 0; // Invalid event, not expired
+    }
+    
+    cJSON* tags = cJSON_GetObjectItem(event, "tags");
+    long expiration_ts = extract_expiration_timestamp(tags);
+    
+    if (expiration_ts == 0) {
+        return 0; // No expiration timestamp, not expired
+    }
+    
+    // Check if current time exceeds expiration + grace period
+    return (current_time > (expiration_ts + g_expiration_config.grace_period));
+}
+
+// Validate event expiration according to NIP-40
+int validate_event_expiration(cJSON* event, char* error_message, size_t error_size) {
+    if (!g_expiration_config.enabled) {
+        return 0; // Expiration validation disabled
+    }
+    
+    if (!event) {
+        snprintf(error_message, error_size, "expiration: null event");
+        return -1;
+    }
+    
+    // Check if event is expired
+    time_t current_time = time(NULL);
+    if (is_event_expired(event, current_time)) {
+        if (g_expiration_config.strict_mode) {
+            cJSON* tags = cJSON_GetObjectItem(event, "tags");
+            long expiration_ts = extract_expiration_timestamp(tags);
+            
+            snprintf(error_message, error_size,
+                    "invalid: event expired (expiration=%ld, current=%ld, grace=%ld)",
+                    expiration_ts, (long)current_time, g_expiration_config.grace_period);
+            log_warning("Event rejected: expired timestamp");
+            return -1;
+        } else {
+            // In non-strict mode, log but allow expired events
+            char debug_msg[256];
+            snprintf(debug_msg, sizeof(debug_msg),
+                    "Accepting expired event (strict_mode disabled)");
+            log_info(debug_msg);
+        }
+    }
+    
+    return 0; // Success
+}
+
 /////////////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////////////////
 //             DATABASE FUNCTIONS
 /////////////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////////////////
 
-// Initialize database connection
+// Initialize database connection and schema
 int init_database() {
-    int rc = sqlite3_open(DATABASE_PATH, &g_db);
+    // Priority 1: Command line database path override
+    const char* db_path = getenv("C_RELAY_DATABASE_PATH_OVERRIDE");
+    
+    // Priority 2: Configuration system (if available)
+    if (!db_path) {
+        db_path = get_config_value("database_path");
+    }
+    
+    // Priority 3: Default path
+    if (!db_path) {
+        db_path = DEFAULT_DATABASE_PATH;
+    }
+    
+    int rc = sqlite3_open(db_path, &g_db);
     if (rc != SQLITE_OK) {
         log_error("Cannot open database");
         return -1;
     }
     
-    log_success("Database connection established");
+    char success_msg[256];
+    snprintf(success_msg, sizeof(success_msg), "Database connection established: %s", db_path);
+    log_success(success_msg);
+    
+    // Check if database is already initialized by looking for the events table
+    const char* check_sql = "SELECT name FROM sqlite_master WHERE type='table' AND name='events'";
+    sqlite3_stmt* check_stmt;
+    rc = sqlite3_prepare_v2(g_db, check_sql, -1, &check_stmt, NULL);
+    if (rc == SQLITE_OK) {
+        int has_events_table = (sqlite3_step(check_stmt) == SQLITE_ROW);
+        sqlite3_finalize(check_stmt);
+        
+        if (has_events_table) {
+            log_info("Database schema already exists, skipping initialization");
+            
+            // Log existing schema version if available
+            const char* version_sql = "SELECT value FROM schema_info WHERE key = 'version'";
+            sqlite3_stmt* version_stmt;
+            if (sqlite3_prepare_v2(g_db, version_sql, -1, &version_stmt, NULL) == SQLITE_OK) {
+                if (sqlite3_step(version_stmt) == SQLITE_ROW) {
+                    const char* db_version = (char*)sqlite3_column_text(version_stmt, 0);
+                    char version_msg[256];
+                    snprintf(version_msg, sizeof(version_msg), "Existing database schema version: %s",
+                             db_version ? db_version : "unknown");
+                    log_info(version_msg);
+                } else {
+                    log_info("Database exists but no version information found");
+                }
+                sqlite3_finalize(version_stmt);
+            }
+        } else {
+            // Initialize database schema using embedded SQL
+            log_info("Initializing database schema from embedded SQL");
+            
+            // Execute the embedded schema SQL
+            char* error_msg = NULL;
+            rc = sqlite3_exec(g_db, EMBEDDED_SCHEMA_SQL, NULL, NULL, &error_msg);
+            if (rc != SQLITE_OK) {
+                char error_log[512];
+                snprintf(error_log, sizeof(error_log), "Failed to initialize database schema: %s",
+                         error_msg ? error_msg : "unknown error");
+                log_error(error_log);
+                if (error_msg) {
+                    sqlite3_free(error_msg);
+                }
+                return -1;
+            }
+            
+            log_success("Database schema initialized successfully");
+            
+            // Log schema version information
+            char version_msg[256];
+            snprintf(version_msg, sizeof(version_msg), "Database schema version: %s",
+                     EMBEDDED_SCHEMA_VERSION);
+            log_info(version_msg);
+        }
+    } else {
+        log_error("Failed to check existing database schema");
+        return -1;
+    }
+    
     return 0;
 }
 
@@ -2082,7 +2331,7 @@ int handle_req_message(const char* sub_id, cJSON* filters, struct lws *wsi, stru
     }
     
     // Check session subscription limits
-    if (pss && pss->subscription_count >= MAX_SUBSCRIPTIONS_PER_CLIENT) {
+    if (pss && pss->subscription_count >= g_subscription_manager.max_subscriptions_per_client) {
         log_error("Maximum subscriptions per client exceeded");
         
         // Send CLOSED notice
@@ -2165,6 +2414,9 @@ int handle_req_message(const char* sub_id, cJSON* filters, struct lws *wsi, stru
         char* sql_ptr = sql + strlen(sql);
         int remaining = sizeof(sql) - strlen(sql);
         
+        // Note: Expiration filtering will be done at application level
+        // after retrieving events to ensure compatibility with all SQLite versions
+        
         // Handle kinds filter
         cJSON* kinds = cJSON_GetObjectItem(filter, "kinds");
         if (kinds && cJSON_IsArray(kinds)) {
@@ -2293,6 +2545,16 @@ int handle_req_message(const char* sub_id, cJSON* filters, struct lws *wsi, stru
             }
             cJSON_AddItemToObject(event, "tags", tags);
             
+            // Check expiration filtering (NIP-40) at application level
+            if (g_expiration_config.enabled && g_expiration_config.filter_responses) {
+                time_t current_time = time(NULL);
+                if (is_event_expired(event, current_time)) {
+                    // Skip this expired event
+                    cJSON_Delete(event);
+                    continue;
+                }
+            }
+            
             // Send EVENT message
             cJSON* event_msg = cJSON_CreateArray();
             cJSON_AddItemToArray(event_msg, cJSON_CreateString("EVENT"));
@@ -2388,14 +2650,20 @@ int handle_event_message(cJSON* event, char* error_message, size_t error_size) {
         return pow_result;  // PoW validation failed, error message already set
     }
     
-    // Step 4: Complete event validation (combines structure + signature + additional checks)
+    // Step 4: Validate expiration timestamp (NIP-40) if enabled
+    int expiration_result = validate_event_expiration(event, error_message, error_size);
+    if (expiration_result != 0) {
+        return expiration_result;  // Expiration validation failed, error message already set
+    }
+    
+    // Step 5: Complete event validation (combines structure + signature + additional checks)
     int validation_result = nostr_validate_event(event);
     if (validation_result != NOSTR_SUCCESS) {
         snprintf(error_message, error_size, "invalid: complete event validation failed");
         return validation_result;
     }
     
-    // Step 5: Check for special event types and handle accordingly
+    // Step 6: Check for special event types and handle accordingly
     cJSON* kind_obj = cJSON_GetObjectItem(event, "kind");
     cJSON* pubkey_obj = cJSON_GetObjectItem(event, "pubkey");
     cJSON* created_at_obj = cJSON_GetObjectItem(event, "created_at");
@@ -2435,7 +2703,7 @@ int handle_event_message(cJSON* event, char* error_message, size_t error_size) {
         }
     }
     
-    // Step 6: Store event in database
+    // Step 7: Store event in database
     if (store_event(event) == 0) {
         error_message[0] = '\0';  // Success - empty error message
         log_success("Event validated and stored successfully");
@@ -2687,7 +2955,7 @@ int start_websocket_relay() {
     log_info("Starting libwebsockets-based Nostr relay server...");
 
     memset(&info, 0, sizeof(info));
-    info.port = DEFAULT_PORT;
+    info.port = get_config_int("relay_port", DEFAULT_PORT);
     info.protocols = protocols;
     info.gid = -1;
     info.uid = -1;
@@ -2713,7 +2981,9 @@ int start_websocket_relay() {
         return -1;
     }
 
-    log_success("WebSocket relay started on ws://127.0.0.1:8888");
+    char startup_msg[256];
+    snprintf(startup_msg, sizeof(startup_msg), "WebSocket relay started on ws://127.0.0.1:%d", info.port);
+    log_success(startup_msg);
 
     // Main event loop with proper signal handling
     while (g_server_running) {
@@ -2749,13 +3019,26 @@ void print_usage(const char* program_name) {
     printf("C Nostr Relay Server\n");
     printf("\n");
     printf("Options:\n");
-    printf("  -p, --port PORT    Listen port (default: %d)\n", DEFAULT_PORT);
-    printf("  -h, --help         Show this help message\n");
+    printf("  -p, --port PORT          Listen port (default: %d)\n", DEFAULT_PORT);
+    printf("  -c, --config FILE        Configuration file path\n");
+    printf("  -d, --config-dir DIR     Configuration directory path\n");
+    printf("  -D, --database-path PATH Database file path (default: %s)\n", DEFAULT_DATABASE_PATH);
+    printf("  -h, --help               Show this help message\n");
+    printf("\n");
+    printf("Examples:\n");
+    printf("  %s --config /path/to/config.json\n", program_name);
+    printf("  %s --config-dir ~/.config/c-relay-dev\n", program_name);
+    printf("  %s --port 9999 --config-dir /etc/c-relay\n", program_name);
+    printf("  %s --database-path /var/lib/c-relay/relay.db\n", program_name);
+    printf("  %s --database-path ./test.db --port 7777\n", program_name);
     printf("\n");
 }
 
 int main(int argc, char* argv[]) {
     int port = DEFAULT_PORT;
+    char* config_dir_override = NULL;
+    char* config_file_override = NULL;
+    char* database_path_override = NULL;
     
     // Parse command line arguments
     for (int i = 1; i < argc; i++) {
@@ -2769,10 +3052,32 @@ int main(int argc, char* argv[]) {
                     log_error("Invalid port number");
                     return 1;
                 }
+                // Port will be stored in configuration system after it's initialized
             } else {
                 log_error("Port argument requires a value");
                 return 1;
             }
+        } else if (strcmp(argv[i], "-c") == 0 || strcmp(argv[i], "--config") == 0) {
+            if (i + 1 < argc) {
+                config_file_override = argv[++i];
+            } else {
+                log_error("Config file argument requires a value");
+                return 1;
+            }
+        } else if (strcmp(argv[i], "-d") == 0 || strcmp(argv[i], "--config-dir") == 0) {
+            if (i + 1 < argc) {
+                config_dir_override = argv[++i];
+            } else {
+                log_error("Config directory argument requires a value");
+                return 1;
+            }
+        } else if (strcmp(argv[i], "-D") == 0 || strcmp(argv[i], "--database-path") == 0) {
+            if (i + 1 < argc) {
+                database_path_override = argv[++i];
+            } else {
+                log_error("Database path argument requires a value");
+                return 1;
+            }
         } else {
             log_error("Unknown argument");
             print_usage(argv[0]);
@@ -2780,31 +3085,155 @@ int main(int argc, char* argv[]) {
         }
     }
     
+    // Store config overrides in global variables for configuration system access
+    if (config_dir_override) {
+        setenv("C_RELAY_CONFIG_DIR_OVERRIDE", config_dir_override, 1);
+    }
+    if (config_file_override) {
+        setenv("C_RELAY_CONFIG_FILE_OVERRIDE", config_file_override, 1);
+    }
+    
     // Set up signal handlers
     signal(SIGINT, signal_handler);
     signal(SIGTERM, signal_handler);
     
     printf(BLUE BOLD "=== C Nostr Relay Server ===" RESET "\n");
     
-    // Initialize database
+    // Apply database path override BEFORE any database operations
+    if (database_path_override) {
+        log_info("Database path override specified from command line");
+        printf("  Override path: %s\n", database_path_override);
+        // Set environment variable so init_database can use the correct path
+        setenv("C_RELAY_DATABASE_PATH_OVERRIDE", database_path_override, 1);
+    }
+    
+    // Initialize database FIRST (required for configuration system)
     if (init_database() != 0) {
         log_error("Failed to initialize database");
         return 1;
     }
     
-    // Initialize nostr library
+    // Database path override is applied via environment variable - no need to store in config
+    // (storing database path in database creates circular dependency)
+    
+    // Initialize nostr library BEFORE configuration system
+    // (required for Nostr event generation in config files)
     if (nostr_init() != 0) {
         log_error("Failed to initialize nostr library");
         close_database();
         return 1;
     }
     
+    // Initialize configuration system (loads file + database + applies to globals)
+    if (init_configuration_system() != 0) {
+        log_error("Failed to initialize configuration system");
+        nostr_cleanup();
+        close_database();
+        return 1;
+    }
+    
+    // Update database_path field to reflect actual database path used
+    if (database_path_override) {
+        // Convert to absolute path and normalize
+        char actual_db_path[1024];
+        if (database_path_override[0] == '/') {
+            // Already absolute
+            strncpy(actual_db_path, database_path_override, sizeof(actual_db_path) - 1);
+        } else {
+            // Make absolute by prepending current working directory
+            char cwd[1024];
+            if (getcwd(cwd, sizeof(cwd))) {
+                // Handle the case where path starts with ./
+                const char* clean_path = database_path_override;
+                if (strncmp(database_path_override, "./", 2) == 0) {
+                    clean_path = database_path_override + 2;
+                }
+                
+                // Ensure we don't exceed buffer size
+                int written = snprintf(actual_db_path, sizeof(actual_db_path), "%s/%s", cwd, clean_path);
+                if (written >= (int)sizeof(actual_db_path)) {
+                    log_warning("Database path too long, using original path");
+                    strncpy(actual_db_path, database_path_override, sizeof(actual_db_path) - 1);
+                    actual_db_path[sizeof(actual_db_path) - 1] = '\0';
+                }
+            } else {
+                strncpy(actual_db_path, database_path_override, sizeof(actual_db_path) - 1);
+            }
+        }
+        actual_db_path[sizeof(actual_db_path) - 1] = '\0';
+        
+        // Update the database_path configuration to reflect actual path used
+        if (set_database_config("database_path", actual_db_path, "system") == 0) {
+            log_info("Updated database_path configuration with actual path used");
+        } else {
+            log_warning("Failed to update database_path configuration");
+        }
+    }
+    
+    // Store metadata about configuration file path used
+    if (strlen(g_config_manager.config_file_path) > 0) {
+        // Convert to absolute path and normalize (fix double slash issue)
+        char actual_config_path[1024];
+        if (g_config_manager.config_file_path[0] == '/') {
+            // Already absolute - use as-is
+            strncpy(actual_config_path, g_config_manager.config_file_path, sizeof(actual_config_path) - 1);
+        } else {
+            // Make absolute by prepending current working directory
+            char cwd[1024];
+            if (getcwd(cwd, sizeof(cwd))) {
+                // Handle the case where path starts with ./
+                const char* clean_path = g_config_manager.config_file_path;
+                if (strncmp(g_config_manager.config_file_path, "./", 2) == 0) {
+                    clean_path = g_config_manager.config_file_path + 2;
+                }
+                
+                // Remove any trailing slash from cwd to avoid double slash
+                size_t cwd_len = strlen(cwd);
+                if (cwd_len > 0 && cwd[cwd_len - 1] == '/') {
+                    cwd[cwd_len - 1] = '\0';
+                }
+                
+                // Remove any leading slash from clean_path to avoid double slash
+                if (clean_path[0] == '/') {
+                    clean_path++;
+                }
+                
+                snprintf(actual_config_path, sizeof(actual_config_path), "%s/%s", cwd, clean_path);
+            } else {
+                strncpy(actual_config_path, g_config_manager.config_file_path, sizeof(actual_config_path) - 1);
+            }
+        }
+        actual_config_path[sizeof(actual_config_path) - 1] = '\0';
+        
+        if (set_database_config("config_location", actual_config_path, "system") == 0) {
+            log_info("Stored configuration location metadata");
+        } else {
+            log_warning("Failed to store configuration location metadata");
+        }
+    }
+    
+    // Apply command line overrides AFTER configuration system is initialized
+    if (port != DEFAULT_PORT) {
+        log_info("Applying port override from command line");
+        printf("  Port: %d\n", port);
+        // Set environment variable for port override (runtime only, not persisted)
+        char port_str[16];
+        snprintf(port_str, sizeof(port_str), "%d", port);
+        setenv("C_RELAY_PORT_OVERRIDE", port_str, 1);
+    }
+    
     // Initialize NIP-11 relay information
     init_relay_info();
     
     // Initialize NIP-13 PoW configuration
     init_pow_config();
     
+    // Initialize NIP-40 expiration configuration
+    init_expiration_config();
+    
+    // Update subscription manager configuration
+    update_subscription_manager_config();
+    
     log_info("Starting relay server...");
     
     // Start WebSocket Nostr relay server
@@ -2812,6 +3241,7 @@ int main(int argc, char* argv[]) {
     
     // Cleanup
     cleanup_relay_info();
+    cleanup_configuration_system();
     nostr_cleanup();
     close_database();
     

src/sql_schema.h

@@ -0,0 +1,299 @@
+/* Embedded SQL Schema for C Nostr Relay
+ * Generated from db/schema.sql - Do not edit manually
+ * Schema Version: 3
+ */
+#ifndef SQL_SCHEMA_H
+#define SQL_SCHEMA_H
+
+/* Schema version constant */
+#define EMBEDDED_SCHEMA_VERSION "4"
+
+/* Embedded SQL schema as C string literal */
+static const char* const EMBEDDED_SCHEMA_SQL = 
+"-- C Nostr Relay Database Schema\n\
+-- SQLite schema for storing Nostr events with JSON tags support\n\
+\n\
+-- Schema version tracking\n\
+PRAGMA user_version = 4;\n\
+\n\
+-- Enable foreign key support\n\
+PRAGMA foreign_keys = ON;\n\
+\n\
+-- Optimize for performance\n\
+PRAGMA journal_mode = WAL;\n\
+PRAGMA synchronous = NORMAL;\n\
+PRAGMA cache_size = 10000;\n\
+\n\
+-- Core events table with hybrid single-table design\n\
+CREATE TABLE events (\n\
+    id TEXT PRIMARY KEY,                -- Nostr event ID (hex string)\n\
+    pubkey TEXT NOT NULL,               -- Public key of event author (hex string)\n\
+    created_at INTEGER NOT NULL,       -- Event creation timestamp (Unix timestamp)\n\
+    kind INTEGER NOT NULL,              -- Event kind (0-65535)\n\
+    event_type TEXT NOT NULL CHECK (event_type IN ('regular', 'replaceable', 'ephemeral', 'addressable')),\n\
+    content TEXT NOT NULL,              -- Event content (text content only)\n\
+    sig TEXT NOT NULL,                  -- Event signature (hex string)\n\
+    tags JSON NOT NULL DEFAULT '[]',   -- Event tags as JSON array\n\
+    first_seen INTEGER NOT NULL DEFAULT (strftime('%s', 'now'))  -- When relay received event\n\
+);\n\
+\n\
+-- Core performance indexes\n\
+CREATE INDEX idx_events_pubkey ON events(pubkey);\n\
+CREATE INDEX idx_events_kind ON events(kind);\n\
+CREATE INDEX idx_events_created_at ON events(created_at DESC);\n\
+CREATE INDEX idx_events_event_type ON events(event_type);\n\
+\n\
+-- Composite indexes for common query patterns\n\
+CREATE INDEX idx_events_kind_created_at ON events(kind, created_at DESC);\n\
+CREATE INDEX idx_events_pubkey_created_at ON events(pubkey, created_at DESC);\n\
+CREATE INDEX idx_events_pubkey_kind ON events(pubkey, kind);\n\
+\n\
+-- Schema information table\n\
+CREATE TABLE schema_info (\n\
+    key TEXT PRIMARY KEY,\n\
+    value TEXT NOT NULL,\n\
+    updated_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now'))\n\
+);\n\
+\n\
+-- Insert schema metadata\n\
+INSERT INTO schema_info (key, value) VALUES\n\
+    ('version', '3'),\n\
+    ('description', 'Hybrid single-table Nostr relay schema with JSON tags and configuration management'),\n\
+    ('created_at', strftime('%s', 'now'));\n\
+\n\
+-- Helper views for common queries\n\
+CREATE VIEW recent_events AS\n\
+SELECT id, pubkey, created_at, kind, event_type, content\n\
+FROM events\n\
+WHERE event_type != 'ephemeral'\n\
+ORDER BY created_at DESC\n\
+LIMIT 1000;\n\
+\n\
+CREATE VIEW event_stats AS\n\
+SELECT \n\
+    event_type,\n\
+    COUNT(*) as count,\n\
+    AVG(length(content)) as avg_content_length,\n\
+    MIN(created_at) as earliest,\n\
+    MAX(created_at) as latest\n\
+FROM events\n\
+GROUP BY event_type;\n\
+\n\
+-- Optimization: Trigger for automatic cleanup of ephemeral events older than 1 hour\n\
+CREATE TRIGGER cleanup_ephemeral_events\n\
+    AFTER INSERT ON events\n\
+    WHEN NEW.event_type = 'ephemeral'\n\
+BEGIN\n\
+    DELETE FROM events \n\
+    WHERE event_type = 'ephemeral' \n\
+    AND first_seen < (strftime('%s', 'now') - 3600);\n\
+END;\n\
+\n\
+-- Replaceable event handling trigger\n\
+CREATE TRIGGER handle_replaceable_events\n\
+    AFTER INSERT ON events\n\
+    WHEN NEW.event_type = 'replaceable'\n\
+BEGIN\n\
+    DELETE FROM events \n\
+    WHERE pubkey = NEW.pubkey \n\
+    AND kind = NEW.kind \n\
+    AND event_type = 'replaceable'\n\
+    AND id != NEW.id;\n\
+END;\n\
+\n\
+-- Persistent Subscriptions Logging Tables (Phase 2)\n\
+-- Optional database logging for subscription analytics and debugging\n\
+\n\
+-- Subscription events log\n\
+CREATE TABLE subscription_events (\n\
+    id INTEGER PRIMARY KEY AUTOINCREMENT,\n\
+    subscription_id TEXT NOT NULL,           -- Subscription ID from client\n\
+    client_ip TEXT NOT NULL,                 -- Client IP address\n\
+    event_type TEXT NOT NULL CHECK (event_type IN ('created', 'closed', 'expired', 'disconnected')),\n\
+    filter_json TEXT,                        -- JSON representation of filters (for created events)\n\
+    events_sent INTEGER DEFAULT 0,           -- Number of events sent to this subscription\n\
+    created_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),\n\
+    ended_at INTEGER,                        -- When subscription ended (for closed/expired/disconnected)\n\
+    duration INTEGER                         -- Computed: ended_at - created_at\n\
+);\n\
+\n\
+-- Subscription metrics summary\n\
+CREATE TABLE subscription_metrics (\n\
+    id INTEGER PRIMARY KEY AUTOINCREMENT,\n\
+    date TEXT NOT NULL,                      -- Date (YYYY-MM-DD)\n\
+    total_created INTEGER DEFAULT 0,         -- Total subscriptions created\n\
+    total_closed INTEGER DEFAULT 0,          -- Total subscriptions closed\n\
+    total_events_broadcast INTEGER DEFAULT 0, -- Total events broadcast\n\
+    avg_duration REAL DEFAULT 0,            -- Average subscription duration\n\
+    peak_concurrent INTEGER DEFAULT 0,       -- Peak concurrent subscriptions\n\
+    updated_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),\n\
+    UNIQUE(date)\n\
+);\n\
+\n\
+-- Event broadcasting log (optional, for detailed analytics)\n\
+CREATE TABLE event_broadcasts (\n\
+    id INTEGER PRIMARY KEY AUTOINCREMENT,\n\
+    event_id TEXT NOT NULL,                  -- Event ID that was broadcast\n\
+    subscription_id TEXT NOT NULL,           -- Subscription that received it\n\
+    client_ip TEXT NOT NULL,                 -- Client IP\n\
+    broadcast_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),\n\
+    FOREIGN KEY (event_id) REFERENCES events(id)\n\
+);\n\
+\n\
+-- Indexes for subscription logging performance\n\
+CREATE INDEX idx_subscription_events_id ON subscription_events(subscription_id);\n\
+CREATE INDEX idx_subscription_events_type ON subscription_events(event_type);\n\
+CREATE INDEX idx_subscription_events_created ON subscription_events(created_at DESC);\n\
+CREATE INDEX idx_subscription_events_client ON subscription_events(client_ip);\n\
+\n\
+CREATE INDEX idx_subscription_metrics_date ON subscription_metrics(date DESC);\n\
+\n\
+CREATE INDEX idx_event_broadcasts_event ON event_broadcasts(event_id);\n\
+CREATE INDEX idx_event_broadcasts_sub ON event_broadcasts(subscription_id);\n\
+CREATE INDEX idx_event_broadcasts_time ON event_broadcasts(broadcast_at DESC);\n\
+\n\
+-- Trigger to update subscription duration when ended\n\
+CREATE TRIGGER update_subscription_duration\n\
+    AFTER UPDATE OF ended_at ON subscription_events\n\
+    WHEN NEW.ended_at IS NOT NULL AND OLD.ended_at IS NULL\n\
+BEGIN\n\
+    UPDATE subscription_events\n\
+    SET duration = NEW.ended_at - NEW.created_at\n\
+    WHERE id = NEW.id;\n\
+END;\n\
+\n\
+-- View for subscription analytics\n\
+CREATE VIEW subscription_analytics AS\n\
+SELECT\n\
+    date(created_at, 'unixepoch') as date,\n\
+    COUNT(*) as subscriptions_created,\n\
+    COUNT(CASE WHEN ended_at IS NOT NULL THEN 1 END) as subscriptions_ended,\n\
+    AVG(CASE WHEN duration IS NOT NULL THEN duration END) as avg_duration_seconds,\n\
+    MAX(events_sent) as max_events_sent,\n\
+    AVG(events_sent) as avg_events_sent,\n\
+    COUNT(DISTINCT client_ip) as unique_clients\n\
+FROM subscription_events\n\
+GROUP BY date(created_at, 'unixepoch')\n\
+ORDER BY date DESC;\n\
+\n\
+-- View for current active subscriptions (from log perspective)\n\
+CREATE VIEW active_subscriptions_log AS\n\
+SELECT\n\
+    subscription_id,\n\
+    client_ip,\n\
+    filter_json,\n\
+    events_sent,\n\
+    created_at,\n\
+    (strftime('%s', 'now') - created_at) as duration_seconds\n\
+FROM subscription_events\n\
+WHERE event_type = 'created'\n\
+AND subscription_id NOT IN (\n\
+    SELECT subscription_id FROM subscription_events\n\
+    WHERE event_type IN ('closed', 'expired', 'disconnected')\n\
+);\n\
+\n\
+-- ================================\n\
+-- CONFIGURATION MANAGEMENT TABLES\n\
+-- ================================\n\
+\n\
+-- Core server configuration table\n\
+CREATE TABLE config (\n\
+    key TEXT PRIMARY KEY,                    -- Configuration key (unique identifier)\n\
+    value TEXT NOT NULL,                     -- Configuration value (stored as string)\n\
+    description TEXT,                        -- Human-readable description\n\
+    config_type TEXT DEFAULT 'user' CHECK (config_type IN ('system', 'user', 'runtime')),\n\
+    data_type TEXT DEFAULT 'string' CHECK (data_type IN ('string', 'integer', 'boolean', 'json')),\n\
+    validation_rules TEXT,                   -- JSON validation rules (optional)\n\
+    is_sensitive INTEGER DEFAULT 0,          -- 1 if value should be masked in logs\n\
+    requires_restart INTEGER DEFAULT 0,      -- 1 if change requires server restart\n\
+    created_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),\n\
+    updated_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now'))\n\
+);\n\
+\n\
+-- Configuration change history table\n\
+CREATE TABLE config_history (\n\
+    id INTEGER PRIMARY KEY AUTOINCREMENT,\n\
+    config_key TEXT NOT NULL,               -- Key that was changed\n\
+    old_value TEXT,                         -- Previous value (NULL for new keys)\n\
+    new_value TEXT NOT NULL,                -- New value\n\
+    changed_by TEXT DEFAULT 'system',       -- Who made the change (system/admin/user)\n\
+    change_reason TEXT,                     -- Optional reason for change\n\
+    changed_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),\n\
+    FOREIGN KEY (config_key) REFERENCES config(key)\n\
+);\n\
+\n\
+-- Configuration validation errors log\n\
+CREATE TABLE config_validation_log (\n\
+    id INTEGER PRIMARY KEY AUTOINCREMENT,\n\
+    config_key TEXT NOT NULL,\n\
+    attempted_value TEXT,\n\
+    validation_error TEXT NOT NULL,\n\
+    error_source TEXT DEFAULT 'validation',  -- validation/parsing/constraint\n\
+    attempted_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now'))\n\
+);\n\
+\n\
+-- Cache for file-based configuration events\n\
+CREATE TABLE config_file_cache (\n\
+    file_path TEXT PRIMARY KEY,             -- Full path to config file\n\
+    file_hash TEXT NOT NULL,                -- SHA256 hash of file content\n\
+    event_id TEXT,                          -- Nostr event ID from file\n\
+    event_pubkey TEXT,                      -- Admin pubkey that signed event\n\
+    loaded_at INTEGER NOT NULL DEFAULT (strftime('%s', 'now')),\n\
+    validation_status TEXT CHECK (validation_status IN ('valid', 'invalid', 'unverified')),\n\
+    validation_error TEXT                   -- Error details if invalid\n\
+);\n\
+\n\
+-- Performance indexes for configuration tables\n\
+CREATE INDEX idx_config_type ON config(config_type);\n\
+CREATE INDEX idx_config_updated ON config(updated_at DESC);\n\
+CREATE INDEX idx_config_history_key ON config_history(config_key);\n\
+CREATE INDEX idx_config_history_time ON config_history(changed_at DESC);\n\
+CREATE INDEX idx_config_validation_key ON config_validation_log(config_key);\n\
+CREATE INDEX idx_config_validation_time ON config_validation_log(attempted_at DESC);\n\
+\n\
+-- Trigger to update timestamp on configuration changes\n\
+CREATE TRIGGER update_config_timestamp\n\
+    AFTER UPDATE ON config\n\
+BEGIN\n\
+    UPDATE config SET updated_at = strftime('%s', 'now') WHERE key = NEW.key;\n\
+END;\n\
+\n\
+-- Trigger to log configuration changes to history\n\
+CREATE TRIGGER log_config_changes\n\
+    AFTER UPDATE ON config\n\
+    WHEN OLD.value != NEW.value\n\
+BEGIN\n\
+    INSERT INTO config_history (config_key, old_value, new_value, changed_by, change_reason)\n\
+    VALUES (NEW.key, OLD.value, NEW.value, 'system', 'configuration update');\n\
+END;\n\
+\n\
+-- Runtime Statistics View\n\
+CREATE VIEW runtime_stats AS\n\
+SELECT\n\
+    key,\n\
+    value,\n\
+    description,\n\
+    updated_at\n\
+FROM config\n\
+WHERE config_type = 'runtime'\n\
+ORDER BY key;\n\
+\n\
+-- Configuration Change Summary\n\
+CREATE VIEW recent_config_changes AS\n\
+SELECT\n\
+    ch.config_key,\n\
+    sc.description,\n\
+    ch.old_value,\n\
+    ch.new_value,\n\
+    ch.changed_by,\n\
+    ch.change_reason,\n\
+    ch.changed_at\n\
+FROM config_history ch\n\
+JOIN config sc ON ch.config_key = sc.key\n\
+ORDER BY ch.changed_at DESC\n\
+LIMIT 50;\n\
+\n\
+-- Runtime Statistics (initialized by server on startup)\n\
+-- These will be populated when configuration system initializes";
+
+#endif /* SQL_SCHEMA_H */

systemd/README.md

@@ -0,0 +1,217 @@
+# C-Relay Systemd Service
+
+This directory contains files for running C-Relay as a Linux systemd service.
+
+## Files
+
+- **`c-relay.service`** - Systemd service unit file
+- **`install-systemd.sh`** - Installation script (run as root)
+- **`uninstall-systemd.sh`** - Uninstallation script (run as root)
+- **`README.md`** - This documentation file
+
+## Quick Start
+
+### 1. Build the relay
+```bash
+# From the project root directory
+make
+```
+
+### 2. Install as systemd service
+```bash
+# Run the installation script as root
+sudo ./systemd/install-systemd.sh
+```
+
+### 3. Start the service
+```bash
+sudo systemctl start c-relay
+```
+
+### 4. Check status
+```bash
+sudo systemctl status c-relay
+```
+
+## Service Details
+
+### Installation Location
+- **Binary**: `/opt/c-relay/c_relay_x86`
+- **Database**: `/opt/c-relay/db/`
+- **Service File**: `/etc/systemd/system/c-relay.service`
+
+### User Account
+- **User**: `c-relay` (system user, no shell access)
+- **Group**: `c-relay`
+- **Home Directory**: `/opt/c-relay`
+
+### Network Configuration
+- **Default Port**: 8888
+- **Default Host**: 127.0.0.1 (localhost only)
+- **WebSocket Endpoint**: `ws://127.0.0.1:8888`
+
+## Configuration
+
+### Environment Variables
+Edit `/etc/systemd/system/c-relay.service` to configure:
+
+```ini
+Environment=C_RELAY_CONFIG_PRIVKEY=your_private_key_here
+Environment=C_RELAY_PORT=8888
+Environment=C_RELAY_HOST=0.0.0.0
+```
+
+After editing, reload and restart:
+```bash
+sudo systemctl daemon-reload
+sudo systemctl restart c-relay
+```
+
+### Security Settings
+The service runs with enhanced security:
+- Runs as unprivileged `c-relay` user
+- No new privileges allowed
+- Protected system directories
+- Private temporary directory
+- Limited file access (only `/opt/c-relay/db` writable)
+- Network restrictions to IPv4/IPv6 only
+
+## Service Management
+
+### Basic Commands
+```bash
+# Start service
+sudo systemctl start c-relay
+
+# Stop service
+sudo systemctl stop c-relay
+
+# Restart service
+sudo systemctl restart c-relay
+
+# Enable auto-start on boot
+sudo systemctl enable c-relay
+
+# Disable auto-start on boot
+sudo systemctl disable c-relay
+
+# Check service status
+sudo systemctl status c-relay
+
+# View logs (live)
+sudo journalctl -u c-relay -f
+
+# View logs (last 100 lines)
+sudo journalctl -u c-relay -n 100
+```
+
+### Log Management
+Logs are handled by systemd's journal:
+```bash
+# View all logs
+sudo journalctl -u c-relay
+
+# View logs from today
+sudo journalctl -u c-relay --since today
+
+# View logs with timestamps
+sudo journalctl -u c-relay --since "1 hour ago" --no-pager
+```
+
+## Database Management
+
+The database is automatically created on first run. Location: `/opt/c-relay/db/c_nostr_relay.db`
+
+### Backup Database
+```bash
+sudo cp /opt/c-relay/db/c_nostr_relay.db /opt/c-relay/db/backup-$(date +%Y%m%d).db
+```
+
+### Reset Database
+```bash
+sudo systemctl stop c-relay
+sudo rm /opt/c-relay/db/c_nostr_relay.db*
+sudo systemctl start c-relay
+```
+
+## Updating the Service
+
+### Update Binary
+1. Build new version: `make`
+2. Stop service: `sudo systemctl stop c-relay`
+3. Replace binary: `sudo cp build/c_relay_x86 /opt/c-relay/`
+4. Set permissions: `sudo chown c-relay:c-relay /opt/c-relay/c_relay_x86`
+5. Start service: `sudo systemctl start c-relay`
+
+### Update Service File
+1. Stop service: `sudo systemctl stop c-relay`
+2. Copy new service file: `sudo cp systemd/c-relay.service /etc/systemd/system/`
+3. Reload systemd: `sudo systemctl daemon-reload`
+4. Start service: `sudo systemctl start c-relay`
+
+## Uninstallation
+
+Run the uninstall script to completely remove the service:
+```bash
+sudo ./systemd/uninstall-systemd.sh
+```
+
+This will:
+- Stop and disable the service
+- Remove the systemd service file
+- Optionally remove the installation directory
+- Optionally remove the `c-relay` user account
+
+## Troubleshooting
+
+### Service Won't Start
+```bash
+# Check detailed status
+sudo systemctl status c-relay -l
+
+# Check logs for errors
+sudo journalctl -u c-relay --no-pager -l
+```
+
+### Permission Issues
+```bash
+# Fix ownership of installation directory
+sudo chown -R c-relay:c-relay /opt/c-relay
+
+# Ensure binary is executable
+sudo chmod +x /opt/c-relay/c_relay_x86
+```
+
+### Port Already in Use
+```bash
+# Check what's using port 8888
+sudo netstat -tulpn | grep :8888
+
+# Or with ss command
+sudo ss -tulpn | grep :8888
+```
+
+### Database Issues
+```bash
+# Check database file permissions
+ls -la /opt/c-relay/db/
+
+# Check database integrity
+sudo -u c-relay sqlite3 /opt/c-relay/db/c_nostr_relay.db "PRAGMA integrity_check;"
+```
+
+## Custom Configuration
+
+For advanced configurations, you can:
+1. Modify the service file for different ports or settings
+2. Use environment files: `/etc/systemd/system/c-relay.service.d/override.conf`
+3. Configure log rotation with journald settings
+4. Set up reverse proxy (nginx/apache) for HTTPS support
+
+## Security Considerations
+
+- The service runs as a non-root user with minimal privileges
+- Database directory is only writable by the c-relay user
+- Consider firewall rules for the relay port
+- For internet-facing relays, use reverse proxy with SSL/TLS
+- Monitor logs for suspicious activity

systemd/c-relay.service

@@ -0,0 +1,43 @@
+[Unit]
+Description=C Nostr Relay Server
+Documentation=https://github.com/your-repo/c-relay
+After=network.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=c-relay
+Group=c-relay
+WorkingDirectory=/opt/c-relay
+ExecStart=/opt/c-relay/c_relay_x86
+Restart=always
+RestartSec=5
+StandardOutput=journal
+StandardError=journal
+SyslogIdentifier=c-relay
+
+# Security settings
+NoNewPrivileges=true
+ProtectSystem=strict
+ProtectHome=true
+ReadWritePaths=/opt/c-relay/db
+PrivateTmp=true
+ProtectKernelTunables=true
+ProtectKernelModules=true
+ProtectControlGroups=true
+
+# Network security
+PrivateNetwork=false
+RestrictAddressFamilies=AF_INET AF_INET6
+
+# Resource limits
+LimitNOFILE=65536
+LimitNPROC=4096
+
+# Environment variables (optional)
+Environment=C_RELAY_CONFIG_PRIVKEY=
+Environment=C_RELAY_PORT=8888
+Environment=C_RELAY_HOST=127.0.0.1
+
+[Install]
+WantedBy=multi-user.target

systemd/install-systemd.sh

@@ -0,0 +1,92 @@
+#!/bin/bash
+
+# C-Relay Systemd Service Installation Script
+# This script installs the C-Relay as a systemd service
+
+set -e
+
+# Configuration
+INSTALL_DIR="/opt/c-relay"
+SERVICE_NAME="c-relay"
+SERVICE_FILE="c-relay.service"
+BINARY_NAME="c_relay_x86"
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+echo -e "${GREEN}=== C-Relay Systemd Service Installation ===${NC}"
+
+# Check if running as root
+if [[ $EUID -ne 0 ]]; then
+   echo -e "${RED}Error: This script must be run as root${NC}"
+   echo "Usage: sudo ./install-systemd.sh"
+   exit 1
+fi
+
+# Check if binary exists (script is in systemd/ subdirectory)
+if [ ! -f "../build/$BINARY_NAME" ]; then
+    echo -e "${RED}Error: Binary ../build/$BINARY_NAME not found${NC}"
+    echo "Please run 'make' from the project root directory first"
+    exit 1
+fi
+
+# Check if service file exists
+if [ ! -f "$SERVICE_FILE" ]; then
+    echo -e "${RED}Error: Service file $SERVICE_FILE not found${NC}"
+    exit 1
+fi
+
+# Create c-relay user if it doesn't exist
+if ! id "c-relay" &>/dev/null; then
+    echo -e "${YELLOW}Creating c-relay user...${NC}"
+    useradd --system --shell /bin/false --home-dir $INSTALL_DIR --create-home c-relay
+else
+    echo -e "${GREEN}User c-relay already exists${NC}"
+fi
+
+# Create installation directory
+echo -e "${YELLOW}Creating installation directory...${NC}"
+mkdir -p $INSTALL_DIR
+mkdir -p $INSTALL_DIR/db
+
+# Copy binary
+echo -e "${YELLOW}Installing binary...${NC}"
+cp ../build/$BINARY_NAME $INSTALL_DIR/
+chmod +x $INSTALL_DIR/$BINARY_NAME
+
+# Set permissions
+echo -e "${YELLOW}Setting permissions...${NC}"
+chown -R c-relay:c-relay $INSTALL_DIR
+
+# Install systemd service
+echo -e "${YELLOW}Installing systemd service...${NC}"
+cp $SERVICE_FILE /etc/systemd/system/
+systemctl daemon-reload
+
+# Enable service
+echo -e "${YELLOW}Enabling service...${NC}"
+systemctl enable $SERVICE_NAME
+
+echo -e "${GREEN}=== Installation Complete ===${NC}"
+echo
+echo -e "${GREEN}Next steps:${NC}"
+echo "1. Configure environment variables in /etc/systemd/system/$SERVICE_FILE if needed"
+echo "2. Start the service: sudo systemctl start $SERVICE_NAME"
+echo "3. Check status: sudo systemctl status $SERVICE_NAME"
+echo "4. View logs: sudo journalctl -u $SERVICE_NAME -f"
+echo
+echo -e "${GREEN}Service commands:${NC}"
+echo "  Start:   sudo systemctl start $SERVICE_NAME"
+echo "  Stop:    sudo systemctl stop $SERVICE_NAME"
+echo "  Restart: sudo systemctl restart $SERVICE_NAME"
+echo "  Status:  sudo systemctl status $SERVICE_NAME"
+echo "  Logs:    sudo journalctl -u $SERVICE_NAME"
+echo
+echo -e "${GREEN}Installation directory: $INSTALL_DIR${NC}"
+echo -e "${GREEN}Service file: /etc/systemd/system/$SERVICE_FILE${NC}"
+echo
+echo -e "${YELLOW}Note: The relay will run on port 8888 by default${NC}"
+echo -e "${YELLOW}Database will be created automatically in $INSTALL_DIR/db/${NC}"

systemd/uninstall-systemd.sh

@@ -0,0 +1,86 @@
+#!/bin/bash
+
+# C-Relay Systemd Service Uninstallation Script
+# This script removes the C-Relay systemd service
+
+set -e
+
+# Configuration
+INSTALL_DIR="/opt/c-relay"
+SERVICE_NAME="c-relay"
+SERVICE_FILE="c-relay.service"
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+echo -e "${GREEN}=== C-Relay Systemd Service Uninstallation ===${NC}"
+
+# Check if running as root
+if [[ $EUID -ne 0 ]]; then
+   echo -e "${RED}Error: This script must be run as root${NC}"
+   echo "Usage: sudo ./uninstall-systemd.sh"
+   exit 1
+fi
+
+# Stop service if running
+echo -e "${YELLOW}Stopping service...${NC}"
+if systemctl is-active --quiet $SERVICE_NAME; then
+    systemctl stop $SERVICE_NAME
+    echo -e "${GREEN}Service stopped${NC}"
+else
+    echo -e "${GREEN}Service was not running${NC}"
+fi
+
+# Disable service if enabled
+echo -e "${YELLOW}Disabling service...${NC}"
+if systemctl is-enabled --quiet $SERVICE_NAME; then
+    systemctl disable $SERVICE_NAME
+    echo -e "${GREEN}Service disabled${NC}"
+else
+    echo -e "${GREEN}Service was not enabled${NC}"
+fi
+
+# Remove systemd service file
+echo -e "${YELLOW}Removing service file...${NC}"
+if [ -f "/etc/systemd/system/$SERVICE_FILE" ]; then
+    rm /etc/systemd/system/$SERVICE_FILE
+    systemctl daemon-reload
+    echo -e "${GREEN}Service file removed${NC}"
+else
+    echo -e "${GREEN}Service file was not found${NC}"
+fi
+
+# Ask about removing installation directory
+echo
+echo -e "${YELLOW}Do you want to remove the installation directory $INSTALL_DIR? (y/N)${NC}"
+read -r response
+if [[ "$response" =~ ^([yY][eE][sS]|[yY])$ ]]; then
+    echo -e "${YELLOW}Removing installation directory...${NC}"
+    rm -rf $INSTALL_DIR
+    echo -e "${GREEN}Installation directory removed${NC}"
+else
+    echo -e "${GREEN}Installation directory preserved${NC}"
+fi
+
+# Ask about removing c-relay user
+echo
+echo -e "${YELLOW}Do you want to remove the c-relay user? (y/N)${NC}"
+read -r response
+if [[ "$response" =~ ^([yY][eE][sS]|[yY])$ ]]; then
+    echo -e "${YELLOW}Removing c-relay user...${NC}"
+    if id "c-relay" &>/dev/null; then
+        userdel c-relay
+        echo -e "${GREEN}User c-relay removed${NC}"
+    else
+        echo -e "${GREEN}User c-relay was not found${NC}"
+    fi
+else
+    echo -e "${GREEN}User c-relay preserved${NC}"
+fi
+
+echo
+echo -e "${GREEN}=== Uninstallation Complete ===${NC}"
+echo -e "${GREEN}C-Relay systemd service has been removed${NC}"

tests/40_nip_test.sh

@@ -0,0 +1,539 @@
+#!/bin/bash
+
+# NIP-40 Expiration Timestamp Test Suite for C Nostr Relay
+# Tests expiration timestamp handling in the relay's event processing pipeline
+
+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'
+
+# Test configuration
+RELAY_URL="ws://127.0.0.1:8888"
+HTTP_URL="http://127.0.0.1:8888"
+TEST_COUNT=0
+PASSED_COUNT=0
+FAILED_COUNT=0
+
+# Test results tracking
+declare -a TEST_RESULTS=()
+
+print_info() {
+    echo -e "${BLUE}[INFO]${RESET} $1"
+}
+
+print_success() {
+    echo -e "${GREEN}${BOLD}[SUCCESS]${RESET} $1"
+}
+
+print_warning() {
+    echo -e "${YELLOW}[WARNING]${RESET} $1"
+}
+
+print_error() {
+    echo -e "${RED}${BOLD}[ERROR]${RESET} $1"
+}
+
+print_test_header() {
+    TEST_COUNT=$((TEST_COUNT + 1))
+    echo ""
+    echo -e "${BOLD}=== TEST $TEST_COUNT: $1 ===${RESET}"
+}
+
+record_test_result() {
+    local test_name="$1"
+    local result="$2"
+    local details="$3"
+    
+    TEST_RESULTS+=("$test_name|$result|$details")
+    
+    if [ "$result" = "PASS" ]; then
+        PASSED_COUNT=$((PASSED_COUNT + 1))
+        print_success "PASS: $test_name"
+    else
+        FAILED_COUNT=$((FAILED_COUNT + 1))
+        print_error "FAIL: $test_name"
+        if [ -n "$details" ]; then
+            echo "       Details: $details"
+        fi
+    fi
+}
+
+# Check if relay is running
+check_relay_running() {
+    print_info "Checking if relay is running..."
+    
+    if ! curl -s -H "Accept: application/nostr+json" "$HTTP_URL/" >/dev/null 2>&1; then
+        print_error "Relay is not running or not accessible at $HTTP_URL"
+        print_info "Please start the relay with: ./make_and_restart_relay.sh"
+        exit 1
+    fi
+    
+    print_success "Relay is running and accessible"
+}
+
+# Test NIP-11 relay information includes NIP-40
+test_nip11_expiration_support() {
+    print_test_header "NIP-11 Expiration Support Advertisement"
+    
+    print_info "Fetching relay information..."
+    RELAY_INFO=$(curl -s -H "Accept: application/nostr+json" "$HTTP_URL/")
+    
+    echo "Relay Info Response:"
+    echo "$RELAY_INFO" | jq '.'
+    echo ""
+    
+    # Check if NIP-40 is in supported_nips
+    if echo "$RELAY_INFO" | jq -e '.supported_nips | index(40)' >/dev/null 2>&1; then
+        print_success "✓ NIP-40 found in supported_nips array"
+        NIP40_SUPPORTED=true
+    else
+        print_error "✗ NIP-40 not found in supported_nips array"
+        NIP40_SUPPORTED=false
+    fi
+    
+    if [ "$NIP40_SUPPORTED" = true ]; then
+        record_test_result "NIP-11 Expiration Support Advertisement" "PASS" "NIP-40 advertised in relay info"
+        return 0
+    else
+        record_test_result "NIP-11 Expiration Support Advertisement" "FAIL" "NIP-40 not advertised"
+        return 1
+    fi
+}
+
+# Helper function to create event with expiration tag
+create_event_with_expiration() {
+    local content="$1"
+    local expiration_timestamp="$2"
+    local private_key="91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe"
+    
+    if ! command -v nak &> /dev/null; then
+        echo ""
+        return 1
+    fi
+    
+    # Create event with expiration tag
+    nak event --sec "$private_key" -c "$content" -t "expiration=$expiration_timestamp" --ts $(date +%s)
+}
+
+# Helper function to send event and check response
+send_event_and_check() {
+    local event_json="$1"
+    local expected_result="$2"  # "accept" or "reject"
+    local description="$3"
+    
+    if [ -z "$event_json" ]; then
+        return 1
+    fi
+    
+    # Create EVENT message
+    local event_message="[\"EVENT\",$event_json]"
+    
+    # Send to relay
+    if command -v websocat &> /dev/null; then
+        local response=$(echo "$event_message" | timeout 5s websocat "$RELAY_URL" 2>&1 || echo "Connection failed")
+        
+        print_info "Relay response: $response"
+        
+        if [[ "$response" == *"Connection failed"* ]]; then
+            print_error "✗ Failed to connect to relay"
+            return 1
+        elif [[ "$expected_result" == "accept" && "$response" == *"true"* ]]; then
+            print_success "✓ $description accepted as expected"
+            return 0
+        elif [[ "$expected_result" == "reject" && "$response" == *"false"* ]]; then
+            print_success "✓ $description rejected as expected"
+            return 0
+        elif [[ "$expected_result" == "accept" && "$response" == *"false"* ]]; then
+            print_error "✗ $description unexpectedly rejected: $response"
+            return 1
+        elif [[ "$expected_result" == "reject" && "$response" == *"true"* ]]; then
+            print_error "✗ $description unexpectedly accepted: $response"
+            return 1
+        else
+            print_warning "? Unclear response for $description: $response"
+            return 1
+        fi
+    else
+        print_error "websocat not found - required for testing"
+        return 1
+    fi
+}
+
+# Test event without expiration tag
+test_event_without_expiration() {
+    print_test_header "Event Submission Without Expiration Tag"
+    
+    if ! command -v nak &> /dev/null; then
+        print_warning "nak command not found - skipping expiration tests"
+        record_test_result "Event Submission Without Expiration Tag" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Creating event without expiration tag..."
+    
+    local private_key="91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe"
+    local event_json=$(nak event --sec "$private_key" -c "Test event without expiration" --ts $(date +%s))
+    
+    print_info "Generated event:"
+    echo "$event_json" | jq '.'
+    echo ""
+    
+    if send_event_and_check "$event_json" "accept" "Event without expiration tag"; then
+        record_test_result "Event Submission Without Expiration Tag" "PASS" "Non-expiring event accepted"
+        return 0
+    else
+        record_test_result "Event Submission Without Expiration Tag" "FAIL" "Non-expiring event handling failed"
+        return 1
+    fi
+}
+
+# Test event with future expiration (should be accepted)
+test_event_with_future_expiration() {
+    print_test_header "Event Submission With Future Expiration"
+    
+    if ! command -v nak &> /dev/null; then
+        record_test_result "Event Submission With Future Expiration" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Creating event with future expiration (1 hour from now)..."
+    
+    local future_timestamp=$(($(date +%s) + 3600))  # 1 hour from now
+    local event_json=$(create_event_with_expiration "Test event expiring in 1 hour" "$future_timestamp")
+    
+    if [ -z "$event_json" ]; then
+        record_test_result "Event Submission With Future Expiration" "FAIL" "Failed to create event"
+        return 1
+    fi
+    
+    print_info "Generated event (expires at $future_timestamp):"
+    echo "$event_json" | jq '.'
+    echo ""
+    
+    if send_event_and_check "$event_json" "accept" "Event with future expiration"; then
+        record_test_result "Event Submission With Future Expiration" "PASS" "Future-expiring event accepted"
+        return 0
+    else
+        record_test_result "Event Submission With Future Expiration" "FAIL" "Future-expiring event rejected"
+        return 1
+    fi
+}
+
+# Test event with past expiration (should be rejected in strict mode)
+test_event_with_past_expiration() {
+    print_test_header "Event Submission With Past Expiration"
+    
+    if ! command -v nak &> /dev/null; then
+        record_test_result "Event Submission With Past Expiration" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Creating event with past expiration (1 hour ago)..."
+    
+    local past_timestamp=$(($(date +%s) - 3600))  # 1 hour ago
+    local event_json=$(create_event_with_expiration "Test event expired 1 hour ago" "$past_timestamp")
+    
+    if [ -z "$event_json" ]; then
+        record_test_result "Event Submission With Past Expiration" "FAIL" "Failed to create event"
+        return 1
+    fi
+    
+    print_info "Generated event (expired at $past_timestamp):"
+    echo "$event_json" | jq '.'
+    echo ""
+    
+    # In strict mode (default), this should be rejected
+    if send_event_and_check "$event_json" "reject" "Event with past expiration"; then
+        record_test_result "Event Submission With Past Expiration" "PASS" "Expired event correctly rejected in strict mode"
+        return 0
+    else
+        record_test_result "Event Submission With Past Expiration" "FAIL" "Expired event handling failed"
+        return 1
+    fi
+}
+
+# Test event with expiration within grace period
+test_event_within_grace_period() {
+    print_test_header "Event Submission Within Grace Period"
+    
+    if ! command -v nak &> /dev/null; then
+        record_test_result "Event Submission Within Grace Period" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Creating event with expiration within grace period (2 minutes ago, grace period is 5 minutes)..."
+    
+    local grace_timestamp=$(($(date +%s) - 120))  # 2 minutes ago (within 5 minute grace period)
+    local event_json=$(create_event_with_expiration "Test event within grace period" "$grace_timestamp")
+    
+    if [ -z "$event_json" ]; then
+        record_test_result "Event Submission Within Grace Period" "FAIL" "Failed to create event"
+        return 1
+    fi
+    
+    print_info "Generated event (expired at $grace_timestamp, within grace period):"
+    echo "$event_json" | jq '.'
+    echo ""
+    
+    # Should be accepted due to grace period
+    if send_event_and_check "$event_json" "accept" "Event within grace period"; then
+        record_test_result "Event Submission Within Grace Period" "PASS" "Event within grace period accepted"
+        return 0
+    else
+        record_test_result "Event Submission Within Grace Period" "FAIL" "Grace period handling failed"
+        return 1
+    fi
+}
+
+# Test event filtering in subscriptions
+test_expiration_filtering_in_subscriptions() {
+    print_test_header "Expiration Filtering in Subscriptions"
+    
+    if ! command -v nak &> /dev/null || ! command -v websocat &> /dev/null; then
+        record_test_result "Expiration Filtering in Subscriptions" "SKIP" "Required tools not available"
+        return 0
+    fi
+    
+    print_info "Setting up test events for subscription filtering..."
+    
+    # First, create a few events with different expiration times
+    local private_key="91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe"
+    
+    # Event 1: No expiration (should be returned)
+    local event1=$(nak event --sec "$private_key" -c "Event without expiration for filtering test" --ts $(date +%s))
+    
+    # Event 2: Future expiration (should be returned)
+    local future_timestamp=$(($(date +%s) + 1800))  # 30 minutes from now
+    local event2=$(create_event_with_expiration "Event with future expiration for filtering test" "$future_timestamp")
+    
+    # Event 3: Past expiration (should NOT be returned if filtering is enabled)
+    local past_timestamp=$(($(date +%s) - 3600))  # 1 hour ago
+    local event3=$(create_event_with_expiration "Event with past expiration for filtering test" "$past_timestamp")
+    
+    print_info "Publishing test events..."
+    
+    # Note: We expect event3 to be rejected on submission in strict mode,
+    # so we'll create it with a slightly more recent expiration that might get through
+    local recent_past=$(($(date +%s) - 600))  # 10 minutes ago (outside grace period)
+    local event3_recent=$(create_event_with_expiration "Recently expired event for filtering test" "$recent_past")
+    
+    # Try to submit all events (some may be rejected)
+    echo "[\"EVENT\",$event1]" | timeout 3s websocat "$RELAY_URL" >/dev/null 2>&1 || true
+    echo "[\"EVENT\",$event2]" | timeout 3s websocat "$RELAY_URL" >/dev/null 2>&1 || true
+    echo "[\"EVENT\",$event3_recent]" | timeout 3s websocat "$RELAY_URL" >/dev/null 2>&1 || true
+    
+    sleep 2  # Let events settle
+    
+    print_info "Testing subscription filtering..."
+    
+    # Create subscription for recent events
+    local req_message='["REQ","filter_test",{"kinds":[1],"limit":10}]'
+    local response=$(echo -e "$req_message\n[\"CLOSE\",\"filter_test\"]" | timeout 5s websocat "$RELAY_URL" 2>/dev/null || echo "")
+    
+    print_info "Subscription response:"
+    echo "$response"
+    echo ""
+    
+    # Count events that contain our test content
+    local no_exp_count=0
+    local future_exp_count=0  
+    local past_exp_count=0
+    
+    if echo "$response" | grep -q "Event without expiration for filtering test"; then
+        no_exp_count=1
+        print_success "✓ Event without expiration found in subscription results"
+    fi
+    
+    if echo "$response" | grep -q "Event with future expiration for filtering test"; then
+        future_exp_count=1
+        print_success "✓ Event with future expiration found in subscription results"
+    fi
+    
+    if echo "$response" | grep -q "Recently expired event for filtering test"; then
+        past_exp_count=1
+        print_warning "✗ Recently expired event found in subscription results (should be filtered)"
+    else
+        print_success "✓ Recently expired event properly filtered from subscription results"
+    fi
+    
+    # Evaluate results
+    local expected_events=$((no_exp_count + future_exp_count))
+    if [ $expected_events -ge 1 ] && [ $past_exp_count -eq 0 ]; then
+        record_test_result "Expiration Filtering in Subscriptions" "PASS" "Expired events properly filtered from subscriptions"
+        return 0
+    else
+        record_test_result "Expiration Filtering in Subscriptions" "FAIL" "Expiration filtering not working properly in subscriptions"
+        return 1
+    fi
+}
+
+# Test malformed expiration tags
+test_malformed_expiration_tags() {
+    print_test_header "Handling of Malformed Expiration Tags"
+    
+    if ! command -v nak &> /dev/null; then
+        record_test_result "Handling of Malformed Expiration Tags" "SKIP" "nak not available"
+        return 0
+    fi
+    
+    print_info "Testing events with malformed expiration tags..."
+    
+    local private_key="91ba716fa9e7ea2fcbad360cf4f8e0d312f73984da63d90f524ad61a6a1e7dbe"
+    
+    # Test 1: Non-numeric expiration value
+    local event1=$(nak event --sec "$private_key" -c "Event with non-numeric expiration" -t "expiration=not_a_number" --ts $(date +%s))
+    
+    # Test 2: Empty expiration value  
+    local event2=$(nak event --sec "$private_key" -c "Event with empty expiration" -t "expiration=" --ts $(date +%s))
+    
+    print_info "Testing non-numeric expiration value..."
+    if send_event_and_check "$event1" "accept" "Event with non-numeric expiration (should be treated as no expiration)"; then
+        print_success "✓ Non-numeric expiration handled gracefully"
+        malformed_test1=true
+    else
+        malformed_test1=false
+    fi
+    
+    print_info "Testing empty expiration value..."
+    if send_event_and_check "$event2" "accept" "Event with empty expiration (should be treated as no expiration)"; then
+        print_success "✓ Empty expiration handled gracefully"
+        malformed_test2=true
+    else
+        malformed_test2=false
+    fi
+    
+    if [ "$malformed_test1" = true ] && [ "$malformed_test2" = true ]; then
+        record_test_result "Handling of Malformed Expiration Tags" "PASS" "Malformed expiration tags handled gracefully"
+        return 0
+    else
+        record_test_result "Handling of Malformed Expiration Tags" "FAIL" "Malformed expiration tag handling failed"
+        return 1
+    fi
+}
+
+# Test configuration via environment variables
+test_expiration_configuration() {
+    print_test_header "Expiration Configuration Via Environment Variables"
+    
+    print_info "Testing expiration configuration from relay logs..."
+    
+    if [ -f "relay.log" ]; then
+        print_info "Current configuration from logs:"
+        grep "Expiration Configuration:" relay.log | tail -1 || print_warning "No expiration configuration found in logs"
+    else
+        print_warning "No relay.log found"
+    fi
+    
+    # The relay should be running with default configuration
+    print_info "Default configuration should be:"
+    print_info "  enabled=true"
+    print_info "  strict_mode=true (rejects expired events on submission)"
+    print_info "  filter_responses=true (filters expired events from responses)"
+    print_info "  grace_period=300 seconds (5 minutes)"
+    
+    # Test current behavior matches expected default configuration
+    print_info "Configuration test based on observed behavior:"
+    
+    # Check if NIP-40 is advertised (indicates enabled=true)
+    if curl -s -H "Accept: application/nostr+json" "$HTTP_URL/" | jq -e '.supported_nips | index(40)' >/dev/null 2>&1; then
+        print_success "✓ NIP-40 support advertised (enabled=true)"
+        config_test=true
+    else
+        print_error "✗ NIP-40 not advertised (may be disabled)"
+        config_test=false
+    fi
+    
+    if [ "$config_test" = true ]; then
+        record_test_result "Expiration Configuration Via Environment Variables" "PASS" "Expiration configuration is accessible and working"
+        return 0
+    else
+        record_test_result "Expiration Configuration Via Environment Variables" "FAIL" "Expiration configuration issues detected"
+        return 1
+    fi
+}
+
+# Print test summary
+print_test_summary() {
+    echo ""
+    echo -e "${BOLD}=== TEST SUMMARY ===${RESET}"
+    echo "Total tests run: $TEST_COUNT"
+    echo -e "${GREEN}Passed: $PASSED_COUNT${RESET}"
+    echo -e "${RED}Failed: $FAILED_COUNT${RESET}"
+    
+    if [ $FAILED_COUNT -gt 0 ]; then
+        echo ""
+        echo -e "${RED}${BOLD}Failed tests:${RESET}"
+        for result in "${TEST_RESULTS[@]}"; do
+            IFS='|' read -r name status details <<< "$result"
+            if [ "$status" = "FAIL" ]; then
+                echo -e "  ${RED}✗ $name${RESET}"
+                if [ -n "$details" ]; then
+                    echo "    $details"
+                fi
+            fi
+        done
+    fi
+    
+    echo ""
+    if [ $FAILED_COUNT -eq 0 ]; then
+        echo -e "${GREEN}${BOLD}🎉 ALL TESTS PASSED!${RESET}"
+        echo -e "${GREEN}✅ NIP-40 Expiration Timestamp support is working correctly in the relay${RESET}"
+        return 0
+    else
+        echo -e "${RED}${BOLD}❌ SOME TESTS FAILED${RESET}"
+        echo "Please review the output above and check relay logs for more details."
+        return 1
+    fi
+}
+
+# Main test execution
+main() {
+    echo -e "${BOLD}=== NIP-40 Expiration Timestamp Relay Test Suite ===${RESET}"
+    echo "Testing NIP-40 Expiration Timestamp support in the C Nostr Relay"
+    echo "Relay URL: $RELAY_URL"
+    echo ""
+    
+    # Check prerequisites
+    if ! command -v curl &> /dev/null; then
+        print_error "curl is required but not installed"
+        exit 1
+    fi
+    
+    if ! command -v jq &> /dev/null; then
+        print_error "jq is required but not installed"
+        exit 1
+    fi
+    
+    if ! command -v websocat &> /dev/null; then
+        print_warning "websocat not found - WebSocket tests will be skipped"
+    fi
+    
+    if ! command -v nak &> /dev/null; then
+        print_warning "nak not found - Event generation tests will be skipped"
+        print_info "Install with: go install github.com/fiatjaf/nak@latest"
+    fi
+    
+    # Run tests
+    check_relay_running
+    test_nip11_expiration_support
+    test_event_without_expiration
+    test_event_with_future_expiration
+    test_event_with_past_expiration
+    test_event_within_grace_period
+    test_expiration_filtering_in_subscriptions
+    test_malformed_expiration_tags
+    test_expiration_configuration
+    
+    # Print summary
+    print_test_summary
+    exit $?
+}
+
+# Run main function
+main "$@"