# Android Architecture

> Standards for Clean Architecture, Modularization, and Unidirectional Data Flow

- Skill: `fierzone/android-architecture` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add fierzone/android-architecture`
- Raw SKILL.md: https://api.skillmd.com/api/skills/fierzone/android-architecture/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: fierzone (https://skillmd.com/u/fierzone)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/fierzone/android-architecture

---


# Android Architecture Standards

## **Priority: P0**

## Implementation Guidelines

### Layering (Clean Architecture)

- **Domain**: Pure Kotlin (No Android deps). Contains UseCases/Models.
- **Data**: Repository impl, DataSources (API/DB). Maps DTO -> Domain.
- **UI**: ViewModel + Composable. Maps Domain -> UiState.

### Modularization

- **Feature Modules**: `:feature:home`, `:feature:profile`.
- **Core Modules**: `:core:ui` (Design System), `:core:network`, `:core:database`.
- **App Module**: DI Root and Navigation Guard.

### Unidirectional Data Flow (UDF)

- **Events**: UI -> ViewModel (Events).
- **State**: ViewModel -> UI (StateFlow<UiState>).

## Anti-Patterns

- **God Activity**: `**No Logic in/Activity**: Host Navigation only.`
- **Direct Repos**: `**No Repo in UI**: Use Type-Safe ViewModels.`
- **Android in Domain**: `**No Context in Domain**: Keep Logic Pure.`

## References

- [Structure & Examples](references/implementation.md)