Amber/AGENTS.md

Repository instructions for Codex / OpenCode

Amber is a single-module Android app (:app, package com.greenart7c3.nostrsigner) — a Nostr event signer (NIP-46 / NIP-55). Despite top-level lib/, commonMain/, androidMain/ dirs, settings.gradle.kts includes only :app; those are not separate Gradle modules.

Toolchain

• JDK 21 required (source/target compat 21). CI and .codex/setup.sh use Temurin 21.
• compileSdk = 37, minSdk = 26, R8 full mode enabled, Gradle parallel + configuration-cache.
• Room schemas are exported to app/schemas via KSP (room.schemaLocation).

Build and validation commands

• ./gradlew ktlintCheck — Kotlin style check (pre-commit hook runs this).
• ./gradlew ktlintFormat — auto-fix formatting issues.
• ./gradlew lint — Android Lint on the default variant; warningsAsErrors is on, so any new warning fails the build (pre-commit and pre-push hooks run this). Version-freshness checks (GradleDependency etc.) are disabled in app/build.gradle.kts; per-path exemptions live in app/lint.xml.
• ./gradlew test --no-daemon — JVM unit tests for all variants (pre-push hook runs ./gradlew test lint).
• Run one test: ./gradlew :app:testFreeDebugUnitTest --tests "com.greenart7c3.nostrsigner.SomeTest" (or --tests "*SomeTest.method").
• ./gradlew assembleDebug --no-daemon — debug APK for both product flavors.
• ./gradlew assembleRelease --no-daemon — release APK; signing only activates when env SIGN_RELEASE is set and keystore.properties exists. CI otherwise touches an empty one.
• ./build.sh <version> <appName> — builds free + offline release APKs/AABs into ~/release/ and calls generate_manifest.sh.

Required order when pushing: ktlintCheck → lint → test → build (mirrored by the hooks, but run them directly; do not rely on hooks).

Releases / version bumps

When asked to "bump the version" / cut a release, do all of the following in a single change — never omit the verification block:

1. Bump versionCode (+1) and versionName (new X.Y.Z) in app/build.gradle.kts (defaultConfig). These are the only places the version lives.
2. Prepend a new ## Amber X.Y.Z block at the top of CHANGELOG.md, summarizing the non-merge commits since the previous vX.Y.Z tag (git log vX.Y.Z..HEAD --no-merges), grouped as user-facing bullets. End the block with the standard "Download it with …" line (update the releases/tag/vX.Y.Z URL) and the "If you like my work …" donation line.
3. Always include the ## Verifying the release block immediately after the donation line (before the next ## Amber heading). Copy it verbatim from the previous release entry and only change the manifest-vX.Y.Z.txt / manifest-vX.Y.Z.txt.sig filenames to the new version. Do not change the gpg --recv-keys key id, the gpg: Signature made Fri 13 Sep 2024 … block, or the surrounding prose — those are key-specific, not release-specific. This block must be part of the version-bump commit, not a follow-up.
4. Do not commit unless explicitly asked (per the global rule). Do not edit build.sh — it takes the version as an argument.

Product flavors (dimension version)

Flavor	Notes
free (default)	Online: OkHttp, Coil, kmptor, relay connectivity. Owns INTERNET/network permissions.
offline	No network stack. app/src/offline/AndroidManifest.xml removes INTERNET/CHANGE_NETWORK_STATE/ACCESS_NETWORK_STATE with tools:node="remove".
benchmark	Mirrors free network deps; applicationIdSuffix=.benchmark, versionNameSuffix=-BENCHMARK; CI builds a signed release per push for side-by-side install.

• Guard any network-only code with BuildFlavorChecker.isOfflineFlavor(). There is also BuildConfig.IS_FDROID_BUILD (false by default; the F-Droid release workflow flips it true and strips REQUEST_INSTALL_PACKAGES via sed) — use it to disable self-update / Zapstore.
• Offline permissions gate: check-offline-permissions.yml runs ./gradlew processOfflineDebugManifest and greps the merged manifest for the three network permissions. Any new dependency that leaks INTERNET etc. will fail this check — verify the offline merged manifest when adding network-capable deps.

Architecture notes (not obvious from filenames)

Three request ingestion paths all converge on Account.sign() / encrypt-decrypt:

1. nostrsigner:// / nostrconnect:// Intent → SignerActivity → IntentUtils → approval bottom sheet.
2. ContentProvider IPC → SignerProvider (synchronous, runBlocking).
3. NIP-46 relay kind 24133 → NotificationSubscription → EventNotificationConsumer → BunkerRequestUtils.

Amber.kt (the Application class) is the DI container: owns applicationIOScope, the Quartz NostrClient, notificationSubscription, isStartingAppState (set during runMigrations() — wait on isStartingAppState.first { !it }), and settings.killSwitch (disconnects all relays when true).

Per-account isolation: every npub gets its own SharedPreferences (prefs_${npub}), AppDatabase (amber_db_${npub}), LogDatabase, and HistoryDatabase — all lazily cached in ConcurrentHashMaps in Amber. Decrypted keys loaded via LocalPreferences.loadFromEncryptedStorage() and cached in LargeCache.

Biometric/PIN lock (useAuth/usePin, SecurityScreen, BiometricAuthScreen) is a UI-only app-launch gate, not a signing gate. SignerProvider and the NIP-46 path never touch it; auto-accept permission rules sign silently on all three paths. Authorization for automatic signing is governed solely by the permission system (ApplicationEntity / ApplicationPermissionsEntity: rememberType, acceptUntil/rejectUntil, kind). Do not wire signing through the biometric prompt.

See CLAUDE.md for the key-files table (verified accurate against the current tree).

Conventions

• ktlint android_studio code style (.editorconfig); star imports effectively disabled; trailing commas allowed; @Composable functions exempt from the function-naming rule. Run ktlintFormat rather than hand-formatting.
• Translations live in app/src/main/res/values-<locale>/strings.xml; MissingTranslation lint is intentionally disabled and the shipped locales are pinned by androidResources.localeFilters in app/build.gradle.kts.
• Git hooks (git-hooks/pre-commit, pre-push) are auto-installed by the root build.gradle.kts installGitHook task wired into :app preBuild. Do not rely on them as a substitute for running checks directly.

Codex Web / cloud setup

Use the committed scripts for cloud environments:

• Setup: bash .codex/setup.sh — installs/verifies Java 21, bootstraps Android cmdline SDK, installs API 36 / build-tools 36.0.0, accepts licenses, and prewarms Gradle for free debug unit-test sources.
• Maintenance: bash .codex/maintenance.sh — refreshes Gradle metadata in cached containers.

Reproducibility

Dockerfile + apkdiff.py verify reproducible builds: docker build -t amber-repro --build-arg VERSION=vX.Y.Z --build-arg APK_TYPE=free-arm64-v8a . then docker run --rm amber-repro (expect APKs match!).