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: { "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: eas build -p ios --profile development --submit This will: Build the development client in the cloud Automatically submit to App Store Connect Send you an email when the build is ready in TestFlight After receiving the TestFlight email: Download the build from TestFlight on your device Launch the app to see the expo-dev-client UI Connect to your local Metro bundler or scan a QR code Building Locally Build a development client on your machine:

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:

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):

Use Xcode Devices window or ideviceinstaller

ideviceinstaller -i build.ipa Install Android build: adb install build.apk Building for Specific Platform

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

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:

Start Metro bundler

npx expo start --dev-client

Scan QR code with dev client or enter URL manually

Troubleshooting Build fails with signing errors: eas credentials Clear build cache: eas build -p ios --profile development --clear-cache Check EAS CLI version: eas --version eas update