# Android Concurrency

> Write correct coroutine scopes, lifecycle collection, and dispatcher injection in Android production code. Use for suspend functions, coroutine scopes, and dispatcher mechanics; defer ViewModel StateFlow/LiveData architecture, Fragment lifecycle recipes, persistence/notifications, and unit-test recipes to their specific skills.

- Skill: `hoangnguyen0403/android-concurrency` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add hoangnguyen0403/android-concurrency`
- Raw SKILL.md: https://api.skillmd.com/api/skills/hoangnguyen0403/android-concurrency/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: HoangNguyen0403 (https://skillmd.com/u/hoangnguyen0403)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/hoangnguyen0403/android-concurrency

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# Android Concurrency Standards

## **Priority: P0 (CRITICAL)**

## Implementation Guidelines

### Structured Concurrency

- **Scopes**: Always use `viewModelScope` (VM) or `lifecycleScope` (Activity/Fragment).
- **Dispatchers**: INJECT Dispatchers (`DispatcherProvider`) for testability. not hardcode `Dispatchers.IO`.

### Flow usage

- **Cold Streams**: Use `Flow` for data streams.
- **Hot Streams**: Use `StateFlow` (State) or `SharedFlow` (Events).
- **Replay**: Use `SharedFlow` with `replay` only when late subscribers must receive recent events.
- **Collection**: Use `collectAsStateWithLifecycle()` (Compose) or `repeatOnLifecycle` (Views).

## Anti-Patterns

- **No GlobalScope**: Use viewModelScope or lifecycleScope — never GlobalScope.
- **No async/await by default**: Prefer simple suspend functions; async only for parallel calls.

## References

- [Dispatcher Pattern](references/implementation.md)


## Canonical response anchors

- Additional task-grounded exact anchors: hardcode