EAS Build

Everything you need to know about Expo Application Services (EAS) Build.

What is EAS Build?

EAS Build is a cloud build service from Expo that compiles your React Native app for iOS and Android. It replaces the deprecated expo build command.

Installation

bash

# Install EAS CLI globally
npm install -g eas-cli

# Login to your Expo account
eas login

# Initialize EAS in your project
eas build:configure

Build Profiles

Configure different build types in eas.json:

eas.json

{
  "build": {
    "development": {
      "developmentClient": true,
      "distribution": "internal"
    },
    "preview": {
      "distribution": "internal"
    },
    "production": {}
  }
}

Development Profile

For local development with Expo Dev Client
Includes debugging tools
Fast iteration

Preview Profile

Internal testing builds
TestFlight or APK distribution
Production-like environment

Production Profile

App Store / Play Store releases
Optimized and minified
No debugging tools

Build Configuration

iOS Configuration

json

{
  "build": {
    "production": {
      "ios": {
        "buildConfiguration": "Release",
        "scheme": "YourApp",
        "simulator": false
      }
    }
  }
}

Android Configuration

json

{
  "build": {
    "production": {
      "android": {
        "buildType": "apk", // or "app-bundle"
        "gradleCommand": ":app:assembleRelease"
      }
    }
  }
}

Credentials Management

iOS Credentials

EAS can manage your certificates automatically:

bash

# Let EAS handle certificates
eas build --platform ios

# Or use your own
eas credentials

Android Keystore

bash

# Generate new keystore (EAS does this automatically)
eas build --platform android

# Use existing keystore
eas credentials

Keep your keystores secure! Losing your Android keystore means you can't update your app.

Environment Variables

In eas.json

json

{
  "build": {
    "production": {
      "env": {
        "EXPO_PUBLIC_API_URL": "https://api.production.com",
        "EXPO_PUBLIC_ANALYTICS_KEY": "prod-key-123"
      }
    },
    "preview": {
      "env": {
        "EXPO_PUBLIC_API_URL": "https://api.staging.com",
        "EXPO_PUBLIC_ANALYTICS_KEY": "staging-key-456"
      }
    }
  }
}

Using Secrets

bash

# Set secret
eas secret:create --scope project --name API_KEY --value "your-secret-key"

# List secrets
eas secret:list

# Delete secret
eas secret:delete --name API_KEY

json

{
  "build": {
    "production": {
      "env": {
        "API_KEY": "$API_KEY" // References secret
      }
    }
  }
}

Build Commands

Start a Build

bash

# Build for specific platform and profile
eas build --platform ios --profile production

# Build both platforms
eas build --platform all --profile production

# Non-interactive build (for CI/CD)
eas build --platform ios --non-interactive

# Auto-submit after build
eas build --platform ios --auto-submit

Monitor Builds

bash

# List recent builds
eas build:list

# View specific build
eas build:view <build-id>

# Cancel build
eas build:cancel <build-id>

Build Caching

Speed up builds with caching:

json

{
  "build": {
    "production": {
      "cache": {
        "key": "production-cache",
        "paths": [
          "node_modules",
          ".expo"
        ]
      }
    }
  }
}

bash

# Clear build cache
eas build --clear-cache

Custom Build Lifecycle

Pre-build Hook

eas.json

{
  "build": {
    "production": {
      "prebuildCommand": "npm run generate-assets"
    }
  }
}

Post-build Hook

json

{
  "build": {
    "production": {
      "postbuildCommand": "npm run upload-sourcemaps"
    }
  }
}

Local Builds

Build locally instead of in the cloud:

bash

# Build locally
eas build --platform ios --local

# Requires Xcode (iOS) or Android Studio (Android)

Build Optimization

Reduce Bundle Size

metro.config.js

module.exports = {
  transformer: {
    minifierConfig: {
      compress: {
        drop_console: true, // Remove console.logs in production
      },
    },
  },
};

Asset Optimization

Use WebP images for better compression
Remove unused fonts and icons
Enable Hermes for Android (enabled by default)

CI/CD Integration

GitHub Actions

.github/workflows/eas-build.yml

name: EAS Build
on:
  push:
    branches: [main]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      
      - uses: expo/expo-github-action@v8
        with:
          eas-version: latest
          token: ${{ secrets.EXPO_TOKEN }}
      
      - name: Install dependencies
        run: npm ci
      
      - name: Build
        run: eas build --platform all --non-interactive --no-wait

Troubleshooting

Build Fails

bash

# View detailed logs
eas build:view <build-id>

# Common fixes:
# 1. Clear cache
eas build --clear-cache

# 2. Update EAS CLI
npm install -g eas-cli@latest

# 3. Check credentials
eas credentials

# 4. Validate configuration
npx expo-doctor

iOS Certificate Issues

Revoke and regenerate certificates via eas credentials
Ensure Bundle ID matches in App Store Connect
Check Apple Developer account permissions

Android Keystore Issues

Verify keystore credentials are correct
Ensure package name is unique
Check Google Play Console access

Best Practices

✅ Use build profiles

Separate development, preview, and production configurations

✅ Store secrets securely

Use eas secret for API keys and tokens

✅ Enable caching

Speed up builds with dependency caching

✅ Test preview builds

Always test with preview builds before production

Next Steps

App Store Submission →

Submit your iOS app

Play Store Submission →

Submit your Android app