expo-dev-client

Use EAS Build to create development clients for testing native code changes on physical devices. Use this for creating custom Expo Go clients for testing branches of your app. ## Important: When Development Clients Are Needed **Only create development clients when your app requires custom native code.** Most apps work fine in Expo Go. You need a dev client ONLY when using: - Local Expo modules (custom native code) - Apple targets (widgets, app clips, extensions) - Third-party native modules not in Expo Go **Try Expo Go first** with `npx expo start`. If everything works, you don't need a dev client. ## EAS Configuration Ensure `eas.json` has a development profile: ```json { "cli": { "version": ">= 16.0.1", "appVersionSource": "remote" }, "build": { "production": { "autoIncrement": true }, "development": { "autoIncrement": true, "developmentClient": true } }, "submit": { "production": {}, "development": {} } } ``` Key settings: - `developmentClient: true` - Bundles expo-dev-client for development builds - `autoIncrement: true` - Automatically increments build numbers - `appVersionSource: "remote"` - Uses EAS as the source of truth for version numbers ## Building for TestFlight Build iOS dev client and submit to TestFlight in one command: ```bash eas build -p ios --profile development --submit ``` This will: 1. Build the development client in the cloud 2. Automatically submit to App Store Connect 3. Send you an email when the build is ready in TestFlight After receiving the TestFlight email: 1. Download the build from TestFlight on your device 2. Launch the app to see the expo-dev-client UI 3. Connect to your local Metro bundler or scan a QR code ## Building Locally Build a development client on your machine: ```bash # iOS (requires Xcode) eas build -p ios --profile development --local # Android eas build -p android --profile development --local ``` Local builds output: - iOS: `.ipa` file - Android: `.apk` or `.aab` file ## Installing Local Builds Install iOS build on simulator: ```bash # Find the .app in the .tar.gz output tar -xzf build-*.tar.gz xcrun simctl install booted ./path/to/App.app ``` Install iOS build on device (requires signing): ```bash # Use Xcode Devices window or ideviceinstaller ideviceinstaller -i build.ipa ``` Install Android build: ```bash adb install build.apk ``` ## Building for Specific Platform ```bash # iOS only eas build -p ios --profile development # Android only eas build -p android --profile development # Both platforms eas build --profile development ``` ## Checking Build Status ```bash # List recent builds eas build:list # View build details eas build:view ``` ## Using the Dev Client Once installed, the dev client provides: - **Development server connection** - Enter your Metro bundler URL or scan QR - **Build information** - View native build details - **Launcher UI** - Switch between development servers Connect to local development: ```bash # Start Metro bundler npx expo start --dev-client # Scan QR code with dev client or enter URL manually ``` ## Troubleshooting **Build fails with signing errors:** ```bash eas credentials ``` **Clear build cache:** ```bash eas build -p ios --profile development --clear-cache ``` **Check EAS CLI version:** ```bash eas --version eas update ```