# Ayush016 Android Lead Agent Skills Android Lead Agent Skills > Android Development Skill - Skill: `tomevault-io/ayush016-android-lead-agent-skills-android-lead-agent-skills` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/ayush016-android-lead-agent-skills-android-lead-agent-skills` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/ayush016-android-lead-agent-skills-android-lead-agent-skills/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/ayush016-android-lead-agent-skills-android-lead-agent-skills --- # Android Development Skill Production-grade Android engineering expertise from data layer to pixel, from startup milliseconds to biometric auth, from phone portrait to foldable landscape. UI quality, performance, security, and accessibility are first-class concerns equal to functional correctness. --- ## ⚡ Quick Decision Guide | Task | Reference | |------|-----------| | Color theming, 29 roles, token hierarchy, gradients | [`theming-and-color.md`](references/theming-and-color.md) | | Building a new screen | [`compose-ui-system.md`](references/compose-ui-system.md) | | Navigation with shared element transitions | [`shared-element-transitions.md`](references/shared-element-transitions.md) | | Type-safe navigation, deep links, multi-module | [`navigation.md`](references/navigation.md) | | Animation / motion (non-shared-element) | [`motion-and-animation.md`](references/motion-and-animation.md) | | Adaptive layouts, large screens, foldables | [`adaptive-layouts.md`](references/adaptive-layouts.md) | | Coroutines, Flow, dispatchers, cancellation | [`coroutines-and-flow.md`](references/coroutines-and-flow.md) | | Room, Retrofit, offline-first data layer | [`data-layer.md`](references/data-layer.md) | | ViewModel, state, DI, architecture | [`architecture.md`](references/architecture.md) | | Baseline Profiles, R8, recomposition perf | [`performance.md`](references/performance.md) | | Encryption, biometrics, cert pinning | [`security.md`](references/security.md) | | WorkManager, Foreground Services, Alarms | [`background-work.md`](references/background-work.md) | | Coil3, SubcomposeAsyncImage, caching | [`image-loading.md`](references/image-loading.md) | | FCM, notification channels, deep links | [`notifications.md`](references/notifications.md) | | TalkBack, semantics, focus, contrast | [`accessibility.md`](references/accessibility.md) | | Unit, screenshot, Roborazzi tests | [`testing.md`](references/testing.md) | | Convention plugins, version catalog, modules | [`build-and-modules.md`](references/build-and-modules.md) | | ADB / Android MCP debugging | [`android-mcp.md`](references/android-mcp.md) | | Pre-ship quality review | [`assets/ui-excellence-checklist.md`](assets/ui-excellence-checklist.md) | --- ## Core Engineering Principles **1. Unidirectional Data Flow, No Exceptions** State flows down from ViewModel. Events flow up via lambdas or actions. No composable reads from a database. No ViewModel imports Compose. The boundary is sharp and testable. **2. Clean Architecture as a Dependency Rule** Domain has zero Android imports. Data is invisible to UI. Features depend on core, never each other. Violations create debt that compounds faster than feature velocity. **3. UI Excellence Is Not Optional** Producing a visually mediocre screen is an engineering failure. Default grey scaffolds, hardcoded colors, missing transitions, and spinners as primary loading states are incomplete work. **4. Shared Element Transitions Are the Default for Content Navigation** Tapping a card must cause the card to flow into its detail. `sharedBounds()` or `sharedElement()` is the default. Opt out only when there is genuinely no spatial relationship to express. **5. Physics Over Timing** `spring()` over `tween()` for gesture-coupled and state-change animations. Tune `stiffness` and `dampingRatio` deliberately — defaults are starting points, not final choices. **6. The 4dp Spacing Grid Is a Contract** Every spacing value is a multiple of 4dp, referenced via `AppSpacing.*` tokens. Arbitrary values are bugs that accumulate into visual dissonance. **7. Fakes Over Mocks** Test ViewModels against in-memory fake implementations. Fakes exercise real contracts, survive refactors. Mocks couple tests to implementation details and silently pass when production code breaks. **8. Performance Is a Feature** Baseline Profiles are committed for every app shipped. Recomposition counts are checked with Layout Inspector before any UI work is done. Cold start is tracked in CI via Macrobenchmark. **9. Security from Day One** Encrypted storage for all sensitive data. Certificate pinning for all network endpoints. No secrets in source code. Input validated at every external boundary. These are not features to add later. **10. Accessibility Is Not Optional** Every image has a content description. Every custom component declares its semantic role. Every interactive element has a 48dp touch target. Colour contrast meets WCAG AA. TalkBack is tested before any screen is shipped. --- ## ★ THE EXTRAORDINARY UI MANDATE ★ Android users have seen a million apps. The ones they remember have something alive about them — a transition that makes content feel like a physical object moving through space, surfaces that catch light at different elevations, a loading state so well crafted it does not feel like waiting. **The Bar.** Every screen passes three tests before it ships: 1. **The scroll-stop test.** Would a designer pause on this if scrolling past it? Not because it is garish — because something is considered. A hierarchy that breathes. A transition that reveals spatial relationship. A surface treatment that says "we care." 2. **The feel test.** Does it respond to touch like a physical object? Spring physics on press, haptic coordination with state changes, skeleton loaders that mirror real content — these are what separate an app people recommend from one people tolerate. 3. **The motion test.** Do transitions communicate where content came from? Shared elements communicate spatial memory. Instant cuts communicate nothing. Slide transitions say you moved sideways. Shared elements say: this is that thing, grown. **In code, this means:** - Shared element transitions for every navigation between related content — always - `spring()` physics tuned for each context; no unexamined defaults - Color exclusively from Material 3 roles; `Brush` gradients where flat color is visually weak - A display typeface for headlines paired with a humanist sans for body - Skeleton screens mirroring the exact geometry of real content — no centred spinners - Edge-to-edge always; status bar and nav bar are part of the design - `Canvas` for anything standard components cannot achieve - Haptic feedback coordinated with meaningful state transitions **Anti-patterns to refuse:** Default grey scaffold backgrounds. Hardcoded hex colors in composables. Instant navigation between related content. `LinearProgressIndicator` as the sole loading state. Cards with identical elevation everywhere. Spacing not on the 4dp grid. --- ## Shared Element Transitions — Overview `SharedTransitionLayout` coordinates geometry between composable trees during navigation. `sharedElement()` matches identical content (image in list → same image in detail). `sharedBounds()` matches composables sharing a spatial region (card → full screen). Three things must thread down: `SharedTransitionScope`, `AnimatedVisibilityScope`, and a stable entity-ID key. Missing any one silently breaks the transition. Full guide, four complete Kotlin patterns, pitfalls: [`references/shared-element-transitions.md`](references/shared-element-transitions.md) --- ## Android MCP Integration MCP = eyes on device. Code = hands in codebase. Build → install → screenshot → compare → refine. Catches what Roborazzi misses: real inset behaviour, animation timing, system bar styling, density quirks. Full capability table, workflows, log filtering, hierarchy inspection: [`references/android-mcp.md`](references/android-mcp.md) --- ## Feature Build Workflow 1. **Module** — Create with `yourapp.android.library.compose` plugin. [`build-and-modules.md`](references/build-and-modules.md) 2. **Routes** — `@Serializable` data class in `:core:navigation`. [`navigation.md`](references/navigation.md) 3. **UI State** — Sealed interface: `Loading`, `Ready(data)`, `Error(message, canRetry)`. [`architecture.md`](references/architecture.md) 4. **Actions** — Sealed interface for all user interactions. 5. **ViewModel** — `StateFlow` + `SharedFlow(replay=0)` + `SavedStateHandle.toRoute()`. [`architecture.md`](references/architecture.md) 6. **Domain** — UseCase → Repository interface → impl in `:core:data`. [`data-layer.md`](references/data-layer.md) 7. **Composables** — Public screen + private sub-composables; `AppSpacing`, `colorScheme`, `typography` only. [`compose-ui-system.md`](references/compose-ui-system.md) 8. **Shared elements** — `sharedElement()` or `sharedBounds()` with stable ID keys. [`shared-element-transitions.md`](references/shared-element-transitions.md) 9. **Motion** — Stagger entry, spring state changes, enter/exit transitions. [`motion-and-animation.md`](references/motion-and-animation.md) 10. **Skeleton loading** — Mirror `Ready` geometry with `ShimmerBox`. [`compose-ui-system.md`](references/compose-ui-system.md) 11. **Adaptive** — Verify on 600dp+; apply `WindowSizeClass`-aware layout. [`adaptive-layouts.md`](references/adaptive-layouts.md) 12. **Accessibility** — Semantics, content descriptions, focus order, 48dp targets. [`accessibility.md`](references/accessibility.md) 13. **Security** — No secrets; input validated at all external boundaries. [`security.md`](references/security.md) 14. **MCP review** — Screenshot in light/dark/large font/RTL; check insets + transitions. [`android-mcp.md`](references/android-mcp.md) 15. **Tests** — ViewModel unit tests + Roborazzi screenshots. [`testing.md`](references/testing.md) 16. **UI excellence** — Every item in [`assets/ui-excellence-checklist.md`](assets/ui-excellence-checklist.md) must pass. --- ## Common Pitfalls **1. Hardcoded colors** — `Color.White` in a composable. Fix: all colors via `MaterialTheme.colorScheme.*`. **2. Missing `modifier` parameter** — Composable cannot be resized by caller. Fix: every public composable takes `modifier: Modifier = Modifier` on its outermost layout. **3. SharedFlow vs StateFlow for events** — Toast fires again on rotation. Fix: events = `MutableSharedFlow(replay=0)`. State = `MutableStateFlow(initial)`. **4. Shared element key mismatch** — Navigation works but no transition fires. Fix: build from stable entity ID. Log both sides and compare. **5. SharedTransitionLayout not wrapping NavHost** — `IllegalStateException: No SharedTransitionScope`. Fix: `SharedTransitionLayout { NavHost { } }` — must contain both source and destination. **6. Missing renderInSharedTransitionScope** — Back button blinks into existence at transition end. Fix: apply `.renderInSharedTransitionScope(scope).animateEnterExit(...)` to destination-only elements. **7. Blocking main thread** — ANR or UI freeze. Fix: `withContext(dispatchers.io)` for all I/O; never `runBlocking` on the main dispatcher. **8. Spinner as only loading state** — `CircularProgressIndicator` centred on a blank background. Fix: `ShimmerBox` composable mirroring `Ready` geometry. **9. Non-4dp spacing** — Visual rhythm feels slightly off; design review flags it. Fix: `AppSpacing.*` for every spacing value. **10. collectAsState instead of collectAsStateWithLifecycle** — Flow collects in background. Fix: always `collectAsStateWithLifecycle()` for UI-bound collection. **11. GlobalScope usage** — Coroutine leaks, ignores cancellation. Fix: `viewModelScope`, `lifecycleScope`, or `rememberCoroutineScope()`. Never `GlobalScope`. **12. Images loaded at full resolution for thumbnails** — OOM in lists. Fix: `.size(width, height)` in `ImageRequest` matching display dimensions. --- > Source: [ayush016/android-lead-agent-skills](https://github.com/ayush016/android-lead-agent-skills) — distributed by [TomeVault](https://tomevault.io).