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.

> **Free locally; cloud builds are paid.** `expo-dev-client` itself is open source and building locally is free. Building or distributing via EAS Build/TestFlight uses your EAS plan's build minutes and needs a paid Apple Developer account for device/TestFlight distribution. See https://expo.dev/pricing.

## Important: When Development Clients Are Needed

**Development clients are the recommended setup for any real or production app.** Expo Go is a playground for learning and quick experiments with the native libraries it bundles; most apps outgrow it and move to a development client. See [Expo Go vs. development builds](https://docs.expo.dev/develop/development-builds/introduction/) for the full reasoning.

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 - Config plugins, or testing remote push notifications and App/Universal Links

## 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 ```

## Submitting Feedback If you encounter errors, misleading or outdated information in this skill, report it so Expo can improve: ```bash npx --yes submit-expo-feedback@latest --category skills --subject "expo-dev-client" "<actionable feedback>" ``` Only submit when you have something specific and actionable to report. Include as much relevant context as possible. If an AI agent repeatedly failed or the user had to take over an Expo task, load the expo-skill-feedback skill and follow its eval-candidate flow instead of reusing the command above.