CometChat

CometChat Calls SDK for Flutter

The CometChat Calls SDK enables real-time voice and video calling capabilities in your Flutter application. Built on top of WebRTC, it provides a complete calling solution with built-in UI components and extensive customization options.

Mobile Showcase

Features

  • 1:1 and group voice/video calls
  • Built-in calling UI with customizable themes
  • Screen sharing
  • Call recording
  • Active speaker detection

Installation

Add the dependency to your pubspec.yaml:

dependencies:
  cometchat_calls_sdk: ^5.1.0

Then run:

flutter pub get

Android setup

  • minSdkVersion 26 or later, compileSdk 36, and Android Gradle Plugin 8.9.1 or later.

  • Add the camera and microphone permissions your calls use, and ask for them at runtime before joining:

    <uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />

  • To keep a call running in the background with an ongoing call notification, declare the plugin's service in your app's AndroidManifest.xml, inside <application>, with the foreground service types your app can justify on Google Play:

    <service
    android:name="com.cometchatcalls.cometchatcalls_plugin.services.OngoingCallService"
    android:exported="false"
    android:foregroundServiceType="microphone|camera" />

    Without it, calls work only while the app is in the foreground: when the app goes to the background, Android stops the microphone and camera, so the other participants hear and see nothing.

iOS setup

The plugin builds with Swift Package Manager only: the native Calls SDK 5.1 is published as a Swift package, not on the CocoaPods trunk. Swift Package Manager is on by default from Flutter 3.44; on an older Flutter, or if your app turned it off, run:

flutter config --enable-swift-package-manager

Apps can still use CocoaPods for their other plugins. If Swift Package Manager is off, pod install stops with these steps.

  • The minimum iOS version is 15.1, and the app builds with Xcode 26.1.1 or later: connectivity_plus 7.1 and later, which the plugin depends on, use the iOS 26 SDK. An app that must build with Xcode 16 can hold connectivity_plus at 7.0.x in its own pubspec.yaml (connectivity_plus: '>=7.0.0 <7.1.0').
  • Add NSCameraUsageDescription and NSMicrophoneUsageDescription to your Info.plist.
  • Apps that also use the Chat SDK v4 need CometChatSDK 4.1.3 or later.

Example

example/ initialises the SDK, logs a user in and joins a call session.

Call lifecycle

On Android and iOS every call below runs the native Calls SDK method of the same name, so a call behaves as it does in a native app. Call init and login first.

// Place a call. The receiver is told it is ringing, and the session starts
// preparing so the join is near-instant once the call is accepted.
CometChatCalls.initiateCall(
  receiver: 'user-2',
  options: InitiateCallOptions(type: CallType.video),
  onSuccess: (InitiatedCall call) { /* show the outgoing call screen */ },
  onError: (CometChatCallsException e) {},
);

// Prepare a session without joining it: signalling only, no media or UI.
CometChatCalls.connect(
  sessionId: sessionId,
  sessionSettings: SessionSettingsBuilder().setPeerCall(true).build(),
  onSuccess: (CallSession session) {},
  onError: (CometChatCallsException e) {},
);

// Join. A session prepared by connect() or initiateCall() is taken over.
CometChatCalls.joinSession(
  sessionId: sessionId,
  sessionSettings: settings,
  onSuccess: (Widget? callView) { /* show it until the call ends */ },
  onError: (CometChatCallsException e) {},
);

// End a call before it is joined: decline, cancel, busy or unanswered.
CometChatCalls.endCall(
  sessionId: sessionId,
  status: EndCallStatus.rejected,
  onSuccess: () {},
  onError: (CometChatCallsException e) {},
);
  • joinSession completes once the native SDK has joined, and hands you the call view. Keep that widget mounted until the call ends: the view holds the running call, and removing it ends it.
  • A session prepared with connect keeps the settings it was prepared with; the settings passed to the join that takes it over are not used.
  • getActiveSession() and getSessionState() report the session in progress. CallSession adds getSessionId(), getCallToken(), getPrepareStatus(), getPrepareError(), isSessionActive() and isSessionJoined().
  • CallSession.leave() leaves the session, or cancels a prepare still in flight. leaveSession() is deprecated in its favour.
  • addIncomingCallListener delivers incoming calls handed to the SDK with injectIncomingCall, which the push notifications SDK does for pushes. The end reasons it reports differ between Android and iOS.
  • setCallKitAudioEnabled(true) (iOS) lets CallKit own the audio session, for apps that report their calls to CallKit.

On web, connect, joinSession, getActiveSession, getSessionState and the CallSession methods above run on the web SDK; getCallToken() reports null there, since the web SDK keeps the token to itself. initiateCall, endCall and the incoming call APIs are Android and iOS only.

Web Support

The SDK supports Flutter web out of the box. During plugin registration it automatically injects everything it needs — the CometChat Calls JavaScript SDK, its stylesheet, and the JS bridge — so no changes to your web/index.html are required. The calling API is identical to mobile.

1. Enable web for your app

flutter config --enable-web
# If your project has no web/ folder yet:
flutter create . --platforms=web

2. Use the SDK

Initialize, log in, then join a session and render the widget returned by joinSession into your widget tree.

import 'package:cometchat_calls_sdk/cometchat_calls_sdk.dart';

// 1. Initialize
final appSettings = (CallAppSettingBuilder()
      ..appId = '<APP_ID>'
      ..region = '<REGION>') // 'us', 'eu' or 'in'
    .build();

CometChatCalls.init(
  appSettings,
  onSuccess: (String message) { /* SDK initialized */ },
  onError: (CometChatCallsException e) { /* handle error */ },
);

// 2. Log in
CometChatCalls.login(
  uid: '<UID>',
  authKey: '<AUTH_KEY>',
  onSuccess: (User? user) { /* logged in */ },
  onError: (CometChatCallsException e) { /* handle error */ },
);

// 3. Join a session and render the returned widget
final sessionSettings = (SessionSettingsBuilder()
      .setTitle('My Meeting')
      .startAudioMuted(false)
      .startVideoPaused(false))
    .build();

CometChatCalls.joinSession(
  sessionId: '<SESSION_ID>',
  sessionSettings: sessionSettings,
  onSuccess: (Widget? callWidget) {
    // Add callWidget to your widget tree, e.g.:
    //   body: SizedBox.expand(child: callWidget)
  },
  onError: (CometChatCallsException e) { /* handle error */ },
);

3. Run it

flutter run -d chrome        # run during development
flutter build web            # production build (serve build/web over HTTPS)

Notes & requirements

  • Internet access — the CometChat Calls JS SDK is loaded from a CDN (unpkg.com) at runtime, so the page needs network access on first load.
  • Secure context — browsers only grant camera/microphone access over HTTPS or on localhost. Serve your production web build over HTTPS.
  • Permissions — the browser prompts for camera/mic on the first call; no Flutter permission plugin is required on web.
  • Browsers — any modern WebRTC-capable browser (Chromium-based, Firefox, Safari).

Help and Support

For issues running the project or integrating with our UI Kits, consult our documentation or create a support ticket or seek real-time support via the CometChat Dashboard.

Libraries

cometchat_calls_sdk