Installing app variants on the same device

When creating development, preview, and production builds, it's common to want to install one of each build on your device at the same time. This allows you to do development work, preview the next version of your app, and run the production version all on the same device, without needing to uninstall and reinstall the app.

In order to be able to have multiple instances of an app installed on your device, each instance must have a unique Application ID (Android) or Bundle Identifier (iOS).

If you have a bare project, you can accomplish this using flavors (Android) and targets (iOS). To configure which flavor is used, use the gradleCommand field on your build profile; to configure which target is used, use the scheme field for iOS.

If you have a managed project, this can be accomplished by using app.config.js and environment variables in eas.json.

Example: configuring development and production variants in a managed project

Let's say we wanted a development build and production build of our managed Expo project. Your eas.json might look like this:

{
  "build": {
    "development": {
      "developmentClient": true
    },
    "production": {}
  }
}

And your app.json might look like this:

{
  "expo": {
    "name": "MyApp",
    "slug": "my-app",
    "ios": {
      "bundleIdentifier": "com.myapp"
    },
    "android": {
      "package": "com.myapp"
    }
  }
}

Let's convert this to app.config.js so we can make it more dynamic:

export default {
  name: "MyApp",
  slug: "my-app",
  ios: {
    bundleIdentifier: "com.myapp",
  },
  android: {
    package: "com.myapp",
  },
};

Now let's switch out the iOS bundleIdentifier and Android package (which becomes the Application ID) based on the presence of an environment variable in app.config.js:

const IS_DEV = process.env.APP_VARIANT === "development";

export default {
  // You can also switch out the app icon and other properties to further
  // differentiate the app on your device.
  name: IS_DEV ? "MyApp (Dev)" : "MyApp",
  slug: "my-app",
  ios: {
    bundleIdentifier: IS_DEV ? "com.myapp.dev" : "com.myapp",
  },
  android: {
    package: IS_DEV ? "com.myapp.dev" : "com.myapp",
  },
};

Note: if you are using any libraries that require you to register your application identifier with an external service to use the SDK, such as Google Maps, you will need to have a separate configuration for that API for the iOS Bundle Identifier and Android Package. You can also swap this configuration in using the same approach as above.

To automatically set the APP_VARIANT environment variable when running builds with the "development" profile, we can use env in eas.json:

{
  "build": {
    "development": {
      "developmentClient": true,
      "env": {
        "APP_VARIANT": "development"
      }
    },
    "production": {}
  }
}

Now when you run eas build --profile development, the environment variable APP_VARIANT will be set to "development" when evaluating app.config.js both locally and on the EAS Build worker. When you start your development server, you will need to run APP_VARIANT=development expo start (or the platform equivalent if you use Windows); a shortcut for this could be to add a script to your package.json such as "dev": "APP_VARIANT=development expo start".

When you run eas build --profile production the APP_VARIANT variable environment will not be set, and the build will run as the production variant.

Note: if you use expo-updates to publish JavaScript updates to your app, you should be cautious to set the correct environment variables for the app variant that you are publishing for when you run the expo publish command. Refer to the EAS Build "Environment variables and secrets" guide for more information.

Example: configuring development and production variants in a bare project

Android

In android/app/build.gradle, create a separate flavor for every build profile from eas.json that you want to build.

android {
    ...
    flavorDimensions "env"
    productFlavors {
        production {
            dimension "env"
            applicationId 'com.myapp'
        }
        development {
            dimension "env"
            applicationId 'com.myapp.dev'
        }
    }
    ...
}

Note: Currently, EAS CLI supports only the applicationId field. If you use applicationIdSuffix inside productFlavors or buildTypes sections then this value will not be detected correctly.

Assign Android flavors to EAS build profiles by specifying a gradleCommand in the eas.json:

{
  "build": {
    "development": {
      "android": {
        "gradleCommand": ":app:assembleDevelopmentDebug"
      }
    },
    "production": {
      "android": {
        "gradleCommand": ":app:bundleProductionRelease"
      }
    }
  }
}

By default, every flavor can be built in either debug or release mode. If you want to restrict some flavor to a specific mode, see the snippet below, and modify build.gradle.

android {
    ...
    variantFilter { variant ->
        def validVariants = [
                ["production", "release"],
                ["development", "debug"],
        ]
        def buildTypeName = variant.buildType*.name
        def flavorName = variant.flavors*.name

        def isValid = validVariants.any { flavorName.contains(it[0]) && buildTypeName.contains(it[1]) }
        if (!isValid) {
            setIgnore(true)
        }
    }
    ...
}

The rest of the configuration at this point is not specific to EAS, it's the same as it would be for any Android project with flavors. There are a few common configurations that you might want to apply to your project:

To change the name of the app built with the development profile, create a android/app/src/development/res/value/strings.xml file.

<resources>
    <string name="app_name">MyApp - Dev</string>
</resources>

To change the icon of the app built with the development profile, create android/app/src/development/res/mipmap-* directories with appropriate assets (you can copy them from android/app/src/main/res and replace the icon files).
To specify google-services.json for a specific flavor put it in a android/app/src/{flavor}/google-services.json file.
To configure sentry, add project.ext.sentryCli = [ flavorAware: true ] to android/app/build.gradle and name your properties file android/sentry-{flavor}-{buildType}.properties (e.g. android/sentry-production-release.properties)

iOS

Assign a distinct scheme to every build profile in eas.json:

{
  "build": {
    "development": {
      "ios": {
        "buildConfiguration": "Debug",
        "scheme": "myapp-dev"
      }
    },
    "production": {
      "ios": {
        "buildConfiguration": "Release",
        "scheme": "myapp"
      }
    }
  }
}

Podfile should have a target defined like this:

target 'myapp' do
    ...
end

Replace it with an abstract target, where common configuration can be copied from the old target.

abstract_target 'common' do
  # put common target configuration here

  target 'myapp' do
  end

  target 'myapp-dev' do
  end
end

Open project in Xcode, click on the project name in the navigation panel, right click on the existing target, and click "Duplicate":

Rename the target to something more meaningful, e.g. myapp copy -> myapp-dev.

Configure a scheme for the new target:

Go to Product -> Scheme -> Manage schemes.
Find scheme myapp copy on the list.
Change scheme name myapp copy -> myapp-dev.
By default, the new scheme should be marked as shared, but Xcode does not create .xcscheme files. To fix that, uncheck the "Shared" checkbox and check it again, after that new .xcscheme file should show up in the ios/myapp.xcodeproj/xcshareddata/xcschemes directory.

By default, the newly created target has separate Info.plist file (in our case it's ios/myapp copy-Info.plist). To simplify your project we recommend using the same file for all targets:

Delete ./ios/myapp copy-Info.plist.
Click on the new target.
Go to Build Settings tab.
Find Packaging section.
Change Info.plist value - myapp copy-Info.plist -> myapp/Info.plist.
Change Product Bundle Identifier.

To change the display name:

Open Info.plist and add key Bundle display name with value $(DISPLAY_NAME).
Open Build Settings for both targets and find User-Defined section.
Add key DISPLAY_NAME with the name you want to use for that target.

To change the app icon:

Create a new image set (you can create it from the existing image set for the current icon, it's usually named AppIcon)
Open Build Settings for the target that you want to change icon.
Find Asset Catalog Compiler - Options section.
Change Primary App Icon Set Name to the name of the new image set.