Add Flutter to existing app

Contents

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.

As of Flutter v1.12, add-to-app is supported for the basic scenario of integrating one full-screen Flutter instance at a time per app. It currently has the following limitations:

  • Running multiple Flutter instances or running in partial screen views may have undefined behavior.
  • 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).
  • As of v1.17, the Flutter module only supports AndroidX applications on Android.

Supported features

Add to Android applications

Add-to-app steps on Android
  • 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. Android plugins should be migrated to the V2 plugins APIs for best add-to-app correctness. As of Flutter v1.12, most of the plugins maintained by the Flutter team as well as FlutterFire have been migrated.
  • 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

Add-to-app steps on iOS
  • 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:

Android
iOS

API usage

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

Android
iOS