Add Flutter to existing app

Add-to-app

It’s sometimes not practical to rewrite your entire application in Flutter all at once. For those situations, Flutter can be integrated into your existing application piecemeal, as a library or module. That module can then be imported into your Android or iOS (currently supported platforms) app to render a part of your app’s UI in Flutter. Or, just to run shared Dart logic.

In a few steps, you can bring the productivity and the expressiveness of Flutter into your own app.

The add-to-app feature supports integrating multiple instances of any screen size. This can help scenarios such as a hybrid navigation stack with mixed native and Flutter screens, or a page with multiple partial-screen Flutter views.

Having multiple Flutter instances allows each instance to maintain independent application and UI state while using minimal memory resources. See more in the multiple Flutters page.

Supported features

Add to Android applications

• Auto-build and import the Flutter module by adding a Flutter SDK hook to your Gradle script.
• Build your Flutter module into a generic Android Archive (AAR) for integration into your own build system and for better Jetifier interoperability with AndroidX.
• FlutterEngine API for starting and persisting your Flutter environment independently of attaching a FlutterActivity/FlutterFragment etc.
• Android Studio Android/Flutter co-editing and module creation/import wizard.
• Java and Kotlin host apps are supported.
• Flutter modules can use Flutter plugins to interact with the platform.
• Support for Flutter debugging and stateful hot reload by using flutter attach from IDEs or the command line to connect to an app that contains Flutter.

Add to iOS applications

• Auto-build and import the Flutter module by adding a Flutter SDK hook to your CocoaPods and to your Xcode build phase.
• Build your Flutter module into a generic iOS Framework for integration into your own build system.
• FlutterEngine API for starting and persisting your Flutter environment independently of attaching a FlutterViewController.
• Objective-C and Swift host apps supported.
• Flutter modules can use Flutter plugins to interact with the platform.
• Support for Flutter debugging and stateful hot reload by using flutter attach from IDEs or the command line to connect to an app that contains Flutter.

See our add-to-app GitHub Samples repository for sample projects in Android and iOS that import a Flutter module for UI.

Get started

To get started, see our project integration guide for Android and iOS:

API usage

After Flutter is integrated into your project, see our API usage guides at the following links:

Limitations

• Packing multiple Flutter libraries into an application isn’t supported.
• Plugins used in add-to-app on Android should migrate to the new Android plugin APIs, based on FlutterPlugin.
• Plugins that don’t support FlutterPlugin might have unexpected behaviors if they make assumptions that are untenable in add-to-app (such as assuming that a Flutter Activity is always present).
• On Android, the Flutter module only supports AndroidX applications.