---
name: android-architecture
description: Apply Clean Architecture layering, modularization, and Unidirectional Data Flow in Android projects. Use when setting up project structure, placing code in layers, configuring feature/core modules, or implementing UDF patterns.
metadata:
triggers:
files:
- "build.gradle.kts"
- "settings.gradle.kts"
keywords:
- clean-architecture
- module
- layers
- domain
- UDF
- unidirectional
- feature module
- core module
- presentation layer
- data layer
---
# Android Architecture Standards
## **Priority: P0 (CRITICAL)**
## 1. Layer Your Project (Clean Architecture)
- **Domain**: Pure Kotlin (No Android deps). Contains UseCases and Models.
- **Data**: Repository impl, DataSources (API/DB). Maps DTO -> Domain.
- **UI**: ViewModel + Composable. Maps Domain -> UiState.
See [structure & examples](references/implementation.md) for Clean Architecture layer examples.
## 2. Modularize by Feature and Core
- **Feature Modules**: `:feature:home`, `:feature:profile`.
- **Core Modules**: `:core:ui` (Design System), `:core:network`, `:core:database`.
- **App Module**: DI Root and Navigation Guard.
See [structure & examples](references/implementation.md) for module configuration.
## 3. Enforce Unidirectional Data Flow (UDF)
- **Events**: UI -> ViewModel (user actions flow UP).
- **State**: ViewModel -> UI (`StateFlow<UiState>` flows DOWN).
## 4. Verify Jetpack Compose Integration
- **Hosting**: Use `setContent` in Activity (No XML Layouts).
- **State**: Hoist state to ViewModel using `collectAsStateWithLifecycle`.
- **Recomposition**: Ensure Composable parameters `@Stable` or `@Immutable`.
- **Navigation**: Use Compose Navigation with Type-Safe destinations.
## Anti-Patterns
- **No Logic in Activity**: Host Navigation only.
- **No Repo in UI**: Access data exclusively via ViewModel.
- **No Context in Domain**: Keep Logic Pure.
## Verification
- [ ] Domain layer has zero Android framework imports.
- [ ] Each feature module compiles independently.
- [ ] State flows one-way: Events UP, State DOWN.
- [ ] `./gradlew build` succeeds.
## References
- [Structure & Examples](references/implementation.md)
- [Jetpack Compose Best Practices](references/compose-standards.md)