# CLAUDE.md — React Native (Expo)

## Commands
- `npx expo start` — start dev server
- `npx expo run:ios` — run on iOS simulator
- `npx expo run:android` — run on Android emulator
- `npm test` — run tests

## Code Style
- Use TypeScript for all files
- Use React Navigation for routing
- Use Zustand for state management
- Use React Query for server state
- Use StyleSheet.create for styles (not inline objects)
- Use Expo modules over bare React Native where available

## Platform Differences
- Use Platform.select or Platform.OS for platform-specific code
- Test on both iOS and Android
- Use SafeAreaView for notch handling
- Use KeyboardAvoidingView for forms

## Performance
- Use FlatList for long lists (never ScrollView)
- Use React.memo for list items
- Minimize re-renders with useCallback
- Use Hermes engine (default in Expo)
- Avoid large images — use expo-image for caching