Build Configuration

The eas.json file in your project root defines how EAS Build compiles your app. This guide covers all configuration options for creating optimized builds.

eas.json Structure

eas.json

{
  "cli": {
    "version": ">= 0.52.0",
    "requireCommit": true,
    "appVersionSource": "remote"
  },
  "build": {
    "development": { /* development profile */ },
    "preview": { /* preview profile */ },
    "production": { /* production profile */ }
  },
  "submit": {
    "production": { /* submission config */ }
  }
}

Top-Level Sections

cli: EAS CLI behavior and requirements
build: Build profiles for different environments
submit: App store submission configuration

CLI Configuration

Control EAS CLI behavior globally:

eas.json

{
  "cli": {
    "version": ">= 0.52.0",
    "requireCommit": true,
    "appVersionSource": "remote",
    "promptToConfigurePushNotifications": false
  }
}

Options:

version: Minimum required EAS CLI version
requireCommit: Require clean git state before builds
appVersionSource: "local" | "remote" - Where to get app version
promptToConfigurePushNotifications: Auto-configure push notifications

Build Profiles

Profiles define different build configurations for various use cases.

Default Profiles

When you run eas build:configure, these profiles are created:

eas.json

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

Profile Inheritance

Extend profiles to reduce duplication:

eas.json

{
  "build": {
    "base": {
      "node": "18.17.0",
      "env": {
        "ENVIRONMENT": "production"
      }
    },
    "production": {
      "extends": "base",
      "channel": "production"
    },
    "staging": {
      "extends": "base",
      "channel": "staging",
      "env": {
        "API_URL": "https://staging.api.example.com"
      }
    }
  }
}

Common Build Options

Options available for all platforms:

Distribution

{
  "distribution": "store"  // or "internal"
}

"store": For app store submission (AAB for Android, IPA for iOS)
"internal": For internal distribution (APK for Android, Ad Hoc for iOS)

EAS Update Channel

{
  "channel": "production"
}

Links builds to EAS Update channels for over-the-air updates.

Development Client

{
  "developmentClient": true
}

Builds a development client with expo-dev-client for debugging.

Environment Variables

{
  "env": {
    "API_URL": "https://api.example.com",
    "FEATURE_FLAG_NEW_UI": "true"
  }
}

Environment variables available during build and in the app runtime (if prefixed with EXPO_PUBLIC_).

Node.js Version

{
  "node": "20.11.0"
}

Specifies Node.js version for the build.

Credentials Source

{
  "credentialsSource": "remote"  // or "local"
}

"remote": Use credentials from EAS servers
"local": Use credentials from credentials.json

Resource Class

{
  "android": {
    "resourceClass": "large"
  },
  "ios": {
    "resourceClass": "large"
  }
}

Options: "default" | "medium" | "large" - Larger classes provide more CPU/memory.

Cache Configuration

{
  "cache": {
    "disabled": false,
    "key": "custom-cache-key",
    "paths": [
      "node_modules",
      ".expo"
    ]
  }
}

Control build caching to speed up subsequent builds.

Android-Specific Options

Configure Android builds:

Build Type

{
  "android": {
    "buildType": "apk"  // or "app-bundle"
  }
}

"app-bundle" (default): Creates AAB for Play Store
"apk": Creates APK for direct installation

Gradle Command

{
  "android": {
    "gradleCommand": ":app:bundleRelease"
  }
}

Custom Gradle command to run. Common commands:

:app:assembleRelease - Build release APK
:app:bundleRelease - Build release AAB
:app:assembleDebug - Build debug APK

Build Image

{
  "android": {
    "image": "sdk-54"  // or "sdk-53", "sdk-52"
  }
}

EAS Build image version (includes Android SDK, NDK, and tools).

Auto-Increment Version Code

{
  "android": {
    "autoIncrement": "versionCode"  // or true
  }
}

Automatically increments versionCode for each build.

NDK Version

{
  "android": {
    "ndk": "26.1.10909125"
  }
}

Specific Android NDK version for native code compilation.

Without Credentials

{
  "android": {
    "withoutCredentials": true
  }
}

Build without code signing (for testing unsigned builds).

Complete Android Example

eas.json

{
  "build": {
    "production-android": {
      "android": {
        "buildType": "app-bundle",
        "gradleCommand": ":app:bundleRelease",
        "image": "sdk-54",
        "resourceClass": "large",
        "autoIncrement": "versionCode",
        "env": {
          "EAS_BUILD_PLATFORM": "android"
        }
      },
      "distribution": "store",
      "channel": "production"
    }
  }
}

iOS-Specific Options

Configure iOS builds:

Simulator Build

{
  "ios": {
    "simulator": true
  }
}

Builds for iOS Simulator (development only, no code signing needed).

Build Configuration

{
  "ios": {
    "buildConfiguration": "Release"  // or "Debug"
  }
}

Xcode build configuration to use.

Scheme

{
  "ios": {
    "scheme": "MyApp"  // Xcode scheme name
  }
}

Specifies which Xcode scheme to build.

Build Image

{
  "ios": {
    "image": "sdk-54"  // or "sdk-53", "sdk-52"
  }
}

EAS Build image version (includes Xcode and related tools).

CocoaPods Version

{
  "ios": {
    "cocoapods": "1.16.2"
  }
}

Specific CocoaPods version for dependency management.

Auto-Increment Build Number

{
  "ios": {
    "autoIncrement": "buildNumber"  // or true
  }
}

Automatically increments CFBundleVersion for each build.

Bundle Identifier

{
  "ios": {
    "bundleIdentifier": "com.example.myapp"
  }
}

Override bundle identifier for this profile (useful for multi-flavor apps).

Enterprise Provisioning

{
  "ios": {
    "enterpriseProvisioning": "universal"  // or "adhoc"
  }
}

For Apple Developer Enterprise Program accounts.

Complete iOS Example

eas.json

{
  "build": {
    "production-ios": {
      "ios": {
        "buildConfiguration": "Release",
        "scheme": "MyApp",
        "image": "sdk-54",
        "cocoapods": "1.16.2",
        "resourceClass": "large",
        "autoIncrement": "buildNumber",
        "simulator": false
      },
      "distribution": "store",
      "channel": "production"
    }
  }
}

Multi-Platform Configurations

Configure both platforms with different settings:

eas.json

{
  "build": {
    "production": {
      "channel": "production",
      "distribution": "store",
      "env": {
        "API_URL": "https://api.example.com"
      },
      "android": {
        "buildType": "app-bundle",
        "image": "sdk-54",
        "resourceClass": "large",
        "autoIncrement": "versionCode"
      },
      "ios": {
        "image": "sdk-54",
        "resourceClass": "medium",
        "autoIncrement": "buildNumber",
        "bundleIdentifier": "com.company.app"
      }
    },
    "preview": {
      "distribution": "internal",
      "channel": "preview",
      "android": {
        "buildType": "apk",
        "gradleCommand": ":app:assembleRelease"
      },
      "ios": {
        "simulator": false
      }
    },
    "development": {
      "developmentClient": true,
      "distribution": "internal",
      "android": {
        "buildType": "apk",
        "gradleCommand": ":app:assembleDebug"
      },
      "ios": {
        "simulator": true,
        "buildConfiguration": "Debug"
      }
    }
  }
}

Environment Variables

Build-Time Variables

Available during the build process only:

{
  "env": {
    "BUILD_NUMBER": "123",
    "CI": "true"
  }
}

Runtime Variables (EXPO_PUBLIC_)

Available in your app code:

{
  "env": {
    "EXPO_PUBLIC_API_URL": "https://api.example.com",
    "EXPO_PUBLIC_ANALYTICS_ID": "UA-12345678"
  }
}

Access in your app:

const apiUrl = process.env.EXPO_PUBLIC_API_URL;

Secret Variables

For sensitive values, use EAS Secrets:

# Set a secret
eas secret:create --name API_SECRET_KEY --value "your-secret-key"

# List secrets
eas secret:list

# Delete a secret
eas secret:delete --name API_SECRET_KEY

Secrets are available as environment variables during build:

{
  "env": {
    "API_KEY": "$API_SECRET_KEY"
  }
}

Platform-Specific Environment Variables

eas.json

{
  "build": {
    "production": {
      "env": {
        "GLOBAL_VAR": "value"
      },
      "android": {
        "env": {
          "ANDROID_ONLY_VAR": "android-value"
        }
      },
      "ios": {
        "env": {
          "IOS_ONLY_VAR": "ios-value"
        }
      }
    }
  }
}

Advanced Configurations

Custom Build Functions

Run custom JavaScript during the build: Create eas-hooks/custom-build.js:

module.exports = async function ({ platform }) {
  console.log(`Running custom build logic for ${platform}`);
  
  // Your custom build logic here
  if (platform === 'android') {
    // Android-specific logic
  } else if (platform === 'ios') {
    // iOS-specific logic
  }
};

Reference in eas.json:

{
  "build": {
    "production": {
      "config": "eas-hooks/custom-build.js"
    }
  }
}

Monorepo Configuration

For monorepo projects:

eas.json

{
  "cli": {
    "appVersionSource": "remote"
  },
  "build": {
    "production": {
      "node": "20.11.0",
      "env": {
        "EXPO_MONOREPO_ROOT": "../.."
      },
      "cache": {
        "paths": [
          "../../node_modules",
          "node_modules"
        ]
      }
    }
  }
}

Build Variants (Android)

Build different flavors of your Android app:

eas.json

{
  "build": {
    "production-free": {
      "android": {
        "gradleCommand": ":app:bundleFreeRelease",
        "env": {
          "APP_VARIANT": "free"
        }
      }
    },
    "production-premium": {
      "android": {
        "gradleCommand": ":app:bundlePremiumRelease",
        "env": {
          "APP_VARIANT": "premium"
        }
      }
    }
  }
}

Multiple Build Configurations

Real-world example with multiple environments:

eas.json

{
  "cli": {
    "version": ">= 0.52.0",
    "requireCommit": true
  },
  "build": {
    "base": {
      "node": "20.11.0",
      "android": {
        "image": "sdk-54"
      },
      "ios": {
        "image": "sdk-54",
        "cocoapods": "1.16.2"
      }
    },
    "development": {
      "extends": "base",
      "developmentClient": true,
      "distribution": "internal",
      "channel": "development",
      "env": {
        "EXPO_PUBLIC_API_URL": "http://localhost:3000",
        "EXPO_PUBLIC_ENV": "development"
      },
      "android": {
        "buildType": "apk"
      },
      "ios": {
        "simulator": true
      }
    },
    "preview": {
      "extends": "base",
      "distribution": "internal",
      "channel": "preview",
      "env": {
        "EXPO_PUBLIC_API_URL": "https://preview-api.example.com",
        "EXPO_PUBLIC_ENV": "preview"
      },
      "android": {
        "buildType": "apk"
      }
    },
    "staging": {
      "extends": "base",
      "distribution": "store",
      "channel": "staging",
      "env": {
        "EXPO_PUBLIC_API_URL": "https://staging-api.example.com",
        "EXPO_PUBLIC_ENV": "staging"
      },
      "android": {
        "buildType": "app-bundle",
        "autoIncrement": "versionCode"
      },
      "ios": {
        "autoIncrement": "buildNumber"
      }
    },
    "production": {
      "extends": "base",
      "distribution": "store",
      "channel": "production",
      "env": {
        "EXPO_PUBLIC_API_URL": "https://api.example.com",
        "EXPO_PUBLIC_ENV": "production"
      },
      "android": {
        "buildType": "app-bundle",
        "resourceClass": "large",
        "autoIncrement": "versionCode"
      },
      "ios": {
        "resourceClass": "large",
        "autoIncrement": "buildNumber"
      }
    }
  },
  "submit": {
    "production": {
      "android": {
        "serviceAccountKeyPath": "./secrets/google-service-account.json",
        "track": "production"
      },
      "ios": {
        "ascAppId": "1234567890"
      }
    }
  }
}

Troubleshooting

Invalid eas.json

EAS CLI validates eas.json against a schema. Use proper JSON syntax and valid option values.

Common errors:

Missing commas between properties
Trailing commas in objects/arrays
Invalid property names
Wrong value types (string vs boolean)

Validate your eas.json:

eas build --platform android --profile production --dry-run

Profile Not Found

Error: Build profile "staging" does not exist in eas.json

Solution: Ensure profile exists in eas.json:

eas build --platform android --profile staging

Profile must be defined:

{
  "build": {
    "staging": { /* ... */ }
  }
}

Environment Variables Not Available

If process.env.EXPO_PUBLIC_API_URL is undefined:

Ensure variable is prefixed with EXPO_PUBLIC_
Rebuild the app (env vars are embedded at build time)
Check eas.json has the variable in the correct profile

Inheritance Issues

When using extends, child profiles override parent values:

{
  "base": {
    "env": { "A": "1", "B": "2" }
  },
  "production": {
    "extends": "base",
    "env": { "B": "3" }  // Only B is overridden, A is inherited
  }
}

Result: Production has A=1 and B=3.

Next Steps

Building Standalone Apps - Create your builds
App Signing - Configure credentials
Internal Distribution - Share builds with team
Over-the-Air Updates - Deploy updates without rebuilding

​Build Configuration

​eas.json Structure

​Top-Level Sections

​CLI Configuration

​Build Profiles

​Default Profiles

​Profile Inheritance

​Common Build Options

​Distribution

​EAS Update Channel

​Development Client

​Environment Variables

​Node.js Version

​Credentials Source

​Resource Class

​Cache Configuration

​Android-Specific Options

​Build Type

​Gradle Command

​Build Image

​Auto-Increment Version Code

​NDK Version

​Without Credentials

​Complete Android Example

​iOS-Specific Options

​Simulator Build

​Build Configuration

​Scheme

​Build Image

​CocoaPods Version

​Auto-Increment Build Number

​Bundle Identifier

​Enterprise Provisioning

​Complete iOS Example

​Multi-Platform Configurations

​Environment Variables

​Build-Time Variables

​Runtime Variables (EXPO_PUBLIC_)

​Secret Variables

​Platform-Specific Environment Variables

​Advanced Configurations

​Custom Build Functions

​Monorepo Configuration

​Build Variants (Android)

​Multiple Build Configurations

​Troubleshooting

​Invalid eas.json

​Profile Not Found

​Environment Variables Not Available

​Inheritance Issues

​Next Steps

Build Configuration

eas.json Structure

Top-Level Sections

CLI Configuration

Build Profiles

Default Profiles

Profile Inheritance

Common Build Options

Distribution

EAS Update Channel

Development Client

Environment Variables

Node.js Version

Credentials Source

Resource Class

Cache Configuration

Android-Specific Options

Build Type

Gradle Command

Build Image

Auto-Increment Version Code

NDK Version

Without Credentials

Complete Android Example

iOS-Specific Options

Simulator Build

Build Configuration

Scheme

Build Image

CocoaPods Version

Auto-Increment Build Number

Bundle Identifier

Enterprise Provisioning

Complete iOS Example

Multi-Platform Configurations

Environment Variables

Build-Time Variables

Runtime Variables (EXPO_PUBLIC_)

Secret Variables

Platform-Specific Environment Variables

Advanced Configurations

Custom Build Functions

Monorepo Configuration

Build Variants (Android)

Multiple Build Configurations

Troubleshooting

Invalid eas.json

Profile Not Found

Environment Variables Not Available

Inheritance Issues

Next Steps