Stringee Flutter

A Flutter plugin for Android and iOS that provides access to Stringee API services. It can be integrated into Flutter applications that need Stringee communication features.

Features

Voice call
Video call
Chat 1-1, chat group
Video conference

Getting Started

Check out our comprehensive Example provided with this plugin.

To use this package, add the dependency to your pubspec.yaml file.

dependencies:
  flutter:
    sdk: flutter
  stringee_plugin: ^1.3.4

See the available versions and release notes in the Changelog.

Android requirements

Android minSdk 21 or later
Android SDK Platform 36 installed

The plugin is compiled with Android API 36. If your application declares its own compileSdk, set it to 36 or later:

android {
    compileSdk = 36
}

Required Android R8 rules are included; the app does not need package-wide Stringee or WebRTC keep rules.

iOS requirements

iOS 15.0 or later
Stringee iOS SDK 2.2.0, which is not published to the CocoaPods trunk. Add it to ios/Podfile before flutter_install_all_ios_pods:

platform :ios, '15.0'

target 'Runner' do
  use_frameworks!

  pod 'Stringee', :podspec => 'https://raw.githubusercontent.com/stringeecom/Stringee-iOS-SDK/2.2.0/Stringee.podspec'

  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
end

Then run pod install (or pod update Stringee when upgrading from an older plugin version). The Stringee pod brings its own WebRTC build; do not add another WebRTC pod to the app.

Basic usage

Create one StringeeClient, subscribe to its event stream, and connect it with an access token generated by your server:

final client = StringeeClient();

final clientSubscription = client.eventStreamController.stream.listen((event) {
  switch (event['eventType']) {
    case StringeeClientEvents.didConnect:
      print('Connected as ${client.userId}');
      break;
    case StringeeClientEvents.requestAccessToken:
      // Fetch a new token from your server, then call client.connect(newToken).
      break;
    case StringeeClientEvents.incomingCall:
      final call = event['body'] as StringeeCall;
      // Present incoming-call UI and call call.initAnswer().
      break;
    case StringeeClientEvents.incomingCall2:
      final call = event['body'] as StringeeCall2;
      // Present incoming-call UI and call call.initAnswer().
      break;
  }
});

await client.connect(accessToken);

Access token renewal

About 60 seconds before the access token expires the client emits StringeeClientEvents.tokenWillExpire. Fetch a new token for the same user from your server and renew it on the open connection:

case StringeeClientEvents.tokenWillExpire:
  final body = event['body'] as Map;
  print('Token expires in ${body['expireInSeconds']}s (exp: ${body['exp']})');
  final newToken = await fetchTokenFromYourServer();
  final result = await client.updateToken(newToken);
  if (result['status'] != true) {
    print('updateToken failed: ${result['code']} ${result['message']}');
  }
  break;

updateToken returns {status, code, message}. The codes are the same on Android and iOS:

Code	Meaning
`0`	Success
`> 0`	Server error: `6` expired token, `10` invalid signature, `17` user or project mismatch
`-1`	Not connected
`-2`	Empty token
`-4`	No server reply within 10 seconds
`-5`	The server has not requested renewal on this connection (call it only after `tokenWillExpire`)

If the token is not renewed, the server closes the connection when it expires and the client emits requestAccessToken (on Android it is preceded by didFailWithError with code 6); the SDK does not reconnect by itself. Call client.connect(newToken) on the same client to resume the session.

Create and observe an outgoing call:

final call = StringeeCall(client);

final callSubscription = call.eventStreamController.stream.listen((event) {
  if (event['eventType'] == StringeeCallEvents.didChangeSignalingState) {
    final state = event['body'] as StringeeSignalingState;
    print('Signaling state: $state');
  }
});

final result = await call.makeCallFromParams(
  MakeCallParams(
    fromUserId,
    toUserId,
    isVideoCall: true,
    videoQuality: VideoQuality.hd,
  ),
);

Video rendering

Use StringeeVideoView for Call or Call2 video. The first argument is the call ID; set isLocal to true for the local camera and false for the remote stream:

Stack(
  children: [
    StringeeVideoView(
      call.id!,
      false,
      scalingType: ScalingType.fill,
    ),
    Positioned(
      right: 16,
      top: 16,
      width: 120,
      height: 160,
      child: StringeeVideoView(
        call.id!,
        true,
        isMirror: true,
        scalingType: ScalingType.fit,
      ),
    ),
  ],
)

On Android, the widget may be created before the native local or remote renderer is ready. The plugin keeps the requested mirror and scaling options, then attaches the renderer when the stream becomes available. A native renderer can belong to only one Android view, so rebuilding it at a new location moves it from the previous container. Removing the Flutter widget clears its pending attachment safely.

For video conference tracks, use track.attach(...), which returns a StringeeVideoView bound to that track:

final remoteView = track.attach(
  scalingType: ScalingType.fit,
  isMirror: false,
);

Release object-level subscriptions when they are no longer needed:

await callSubscription.cancel();
call.destroy();
await clientSubscription.cancel();
await client.disconnect();

StringeeCall2, StringeeChat, and StringeeVideoRoom expose their own event streams. Call their destroy() method after use so the plugin can close the corresponding stream subscription.

API documentation

Public Flutter APIs include DartDoc for classes, constructors, fields, event values, and methods. Generate browsable API documentation locally with:

dart doc --validate-links

The generated site is written to doc/api/index.html. Android bridge classes and methods include JavaDoc that is available in IDE source documentation.

Check out our getting-started guides:

License

This project is licensed under the BSD 3-Clause License - see the LICENSE file for details.