claude-android-ninja

Android Agent Skill

This repository is an Agent Skill package for Android development with Kotlin and Jetpack Compose.
It provides a structured set of instructions, templates, and references that help agents build production-quality Android apps consistently and efficiently.

Learn more about the Agent Skills format here: agentskills.io

Browse this skill on SkillsMP

What This Skill Covers

• Modular Android architecture (feature-first, core modules, strict dependencies)
• Domain/Data/UI layering patterns with auth-focused examples
• Jetpack Compose patterns, state management, animation, side effects, modifiers, and adaptive UI (NavigationSuiteScaffold, ListDetailPaneScaffold, SupportingPaneScaffold)
• Edge-to-edge display and predictive back gesture handling
• Material 3 theming (dynamic colors, typography, shapes, 8dp spacing tokens, app-category style fit, reserved resource names, dark/light mode)
• Navigation3 guidance (stable catalog pin, deep-link routing, SavedState Compose with NavKey), adaptive navigation, and large-screen quality tiers (phones, tablets, foldables, input expectations)
• Accessibility support (TalkBack, semantic properties, label copy, live regions, Espresso accessibility checks, WCAG alignment)
• Internationalization & localization (i18n/l10n, RTL support, plurals)
• Notifications (channels, styles, actions, foreground services, progress-centric, media/audio focus, PiP, system sharesheet, Navigation3 state from taps)
• Background media playback hardening at target SDK 37 (Media3 MediaSessionService for audio and video, mediaPlayback foreground service type, FOREGROUND_SERVICE_MEDIA_PLAYBACK permission, standalone MediaPlayer/AudioTrack forbidden in background, requestAudioFocus enforcement) and Media3 ExoPlayer catalog wiring with playback preloading guidance
• Data synchronization & offline-first (sync strategies, conflict resolution, cache invalidation)
• Material Symbols icons, adaptive launcher icon specs, graphics, custom drawing with Canvas, and Coil3 image loading patterns (AsyncImage, SubcomposeAsyncImage, Hilt ImageLoader)
• Gradle/build conventions, product flavors and BuildConfig, version catalog usage, KSP migration, Spotless formatting, and build performance optimization (diagnostics, lazy tasks, configuration cache)
• Testing practices with fakes, Hilt testing, Room 3 testing (SQLiteDriver, room3-testing), Compose Preview Screenshot Testing and Roborazzi trade routing, pre-release UI state checklist (empty, loading, error, offline, permissions), ADB device targeting, install or launch smoke, and UIAutomator black-box checks (references/testing.md)
• Coroutines patterns, structured concurrency, Flow (callbackFlow, backpressure, combine, shareIn), and common pitfalls
• Kotlin delegation patterns and composition over inheritance
• Dependency management rules and templates
• Crash reporting with provider-agnostic interfaces (Firebase/Sentry)
• Runtime permissions with Compose patterns (references/android-permissions.md) including contact picker, Embedded Photo Picker, and Android 17 location privacy; media playback, picking, FileProvider, and sharesheet routing (references/android-media.md)
• Performance benchmarking (Macrobenchmark, Microbenchmark, Baseline Profiles, ProfileInstaller, System Tracing), Android Performance Analyzer (APA) for Studio system traces, Perfetto UI for attached traces, Google Play Vitals context (crash/ANR bars, startup targets, frame budgets, battery/background), optional Play Developer Reporting API vitals, Compose recomposition optimization (three phases, deferred state reads, Strong Skipping Mode), and app startup optimization (App Startup library, splash screen, lazy initialization)
• StrictMode guardrails and Compose compiler stability diagnostics
• Code coverage with JaCoCo (unit + instrumented tests)
• Security (certificate pinning, encryption, biometrics, Credential Manager and passkeys, device identifiers and privacy, Play Data safety, Play Integrity Standard/Classic with server decodeIntegrityToken, requestHash/nonce binding, tiered policy, remediation, URI grants on outbound intents, local root/emulator checks as supplementary)
• Retrofit/networking patterns (service interfaces, nullable JSON DTOs, Hilt NetworkModule, AuthInterceptor)
• Haptic feedback, touch targets, and forms/input patterns (keyboard types, autofill, validation)
• Debugging guide (Logcat levels, ANR timeouts, Gradle error patterns, LeakCanary, Compose recomposition, R8 mapping and manual de-obfuscation, R8 keep-rules troubleshooting, process kill under memory caps / memory-limiter reproduction)
• Consolidated migration guide (XML to Compose, LiveData to StateFlow, RxJava to Coroutines, Navigation 2.x to Navigation3, Accompanist to official APIs, Material 2 to 3, Edge-to-Edge, Room 2.x to Room 3 (composite @Relation / @Junction keys), Android 17 / API 37 checklist (memory limiter, location privacy), 16 KB native page size and Play alignment, Compose-XML interop hardening, Splash Screen API; references/migration.md)
• Code quality with Detekt and Compose rules
• Play CI/CD: AAB, release tracks, signing boundaries, staged rollout, upload automation (fastlane vs Gradle Play Publisher routing), and Play developer identity verification (Console human step outside the repo; references/android-ci-cd.md)

Key Files

• SKILL.md - entry point (Quick Reference, Examples, Troubleshooting)
• references/INDEX.md - summary table of all reference files and quick companions (~50 lines)
• references/INDEX-sections.md - detailed section anchors (open only when quick routing is insufficient)
• references/workflows.md - extended task routing when Quick Reference is not enough
• references/architecture.md - architecture principles, data/domain/ui/common layers, nullable network DTOs, and flows
• references/modularization.md - module structure, dependency rules, and feature module creation
• references/android-navigation.md - Navigation3 (stable pin, deep links, shared elements), adaptive navigation, large-screen quality tiers
• references/compose-patterns.md - Compose patterns, Material motion, animation, side effects, modifiers, stability, and migrations
• references/android-theming.md - Material 3 theming, spacing tokens, category style, colors, typography, shapes
• references/android-accessibility.md - accessibility, TalkBack, label copy, semantic properties, WCAG
• references/android-i18n.md - internationalization, localization, RTL support, plurals
• references/android-notifications.md - notifications, channels, media/PiP/sharesheet, foreground services
• references/android-media.md - picking and sharing media/files (router), background playback at API 37 (Media3 MediaSessionService, FGS type, audio focus), and playback preloading
• references/android-data-sync.md - offline-first, sync strategies, conflict resolution
• references/kotlin-patterns.md - Kotlin best practices and View lifecycle interop (must-read for Kotlin code)
• references/coroutines-patterns.md - coroutines best practices and patterns
• references/gradle-setup.md - build logic, product flavors, BuildConfig, conventions, R8 Keep-Rules Audit, build files, and registering optional root tasks (for example Play Vitals reporting)
• references/android-ci-cd.md - Play release AAB, tracks, signing boundaries, staged rollout, developer verification, bundletool sideloads, CI release lane ordering
• references/testing.md - testing patterns with fakes, Hilt, Room 3, Navigation3, Compose and UIAutomator smoke, ADB device targeting, pre-release UI state checklist, Preview vs Roborazzi visual regression routing, deep links, and screenshot testing
• references/android-graphics.md - Material Symbols icons, adaptive launcher icons, Canvas drawing, Palette API
• references/android-permissions.md - runtime permissions, contact picker, Embedded Photo Picker, Android 17 location privacy
• references/kotlin-delegation.md - delegation patterns and composition guidance
• references/crashlytics.md - crash reporting with modular provider swaps
• references/android-strictmode.md - StrictMode guardrails and Compose stability
• references/android-code-coverage.md - JaCoCo code coverage setup and CI integration
• references/android-security.md - Play Integrity (Standard/Classic), server decode and verdict policy, requestHash/nonce, errors/remediation, device trust vs local root checks, Credential Manager, pinning, encryption, Data safety
• references/code-quality.md - Detekt setup and code quality rules
• references/dependencies.md - dependency rules and version catalog guidance (Navigation3, Room 3, Media3, SavedState Compose pins)