Voip Calling

CometChat Calls SDK v5 — VoIP Calling (Flutter)

Overview

VoIP calling enables system-level call integration — incoming call notifications even when the app is killed, native call UI on iOS (CallKit), and ConnectionService on Android.

Prerequisites

• Both Chat SDK and Calls SDK initialized
• Push notification service configured (FCM for Android, APNs/PushKit for iOS)
• VoIP certificate (iOS) or FCM server key (Android)

Implementation

iOS — CallKit Integration

The native iOS SDK handles CallKit automatically when configured. Add to Info.plist:

<key>UIBackgroundModes</key>
<array>
    <string>audio</string>
    <string>voip</string>
    <string>remote-notification</string>
</array>

Android — ConnectionService

Add to AndroidManifest.xml:

<uses-permission android:name="android.permission.MANAGE_OWN_CALLS" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE_PHONE_CALL" />
<uses-permission android:name="android.permission.POST_NOTIFICATIONS" />

Push Notification Handling

When a push notification arrives for an incoming call:

// 1. Parse the push payload to extract call data
// 2. Show incoming call UI (or trigger system call UI)
// 3. On accept: initialize SDK if needed, login, then joinSession

void handleIncomingCallPush(Map<String, dynamic> payload) {
  final sessionId = payload['sessionId'];
  final callerName = payload['callerName'];
  final callType = payload['callType']; // "audio" or "video"

  // Show your incoming call screen
  showIncomingCallScreen(
    sessionId: sessionId,
    callerName: callerName,
    callType: callType,
  );
}

void acceptCallFromPush(String sessionId, String callType) async {
  // Ensure SDK is initialized and user is logged in
  // Then join the session
  final settings = SessionSettingsBuilder()
      .setType(callType == "audio" ? SessionType.audio : SessionType.video)
      .build();

  CometChatCalls.joinSession(
    sessionId: sessionId,
    sessionSettings: settings,
    onSuccess: (Widget? widget) {
      // Navigate to call screen
    },
    onError: (e) => debugPrint("Join failed: ${e.message}"),
  );
}

Platform-Specific Packages

Consider using these Flutter packages for VoIP integration:

• flutter_callkit_incoming — Show native incoming call UI on both platforms
• firebase_messaging — FCM push notifications
• flutter_voip_push_notification — iOS VoIP push handling

Gotchas

• VoIP push notifications require server-side configuration
• iOS requires a VoIP certificate from Apple Developer Portal
• Android 13+ requires POST_NOTIFICATIONS runtime permission
• The SDK must be initialized before joining a session from a push notification
• CallKit on iOS shows the native green phone UI for incoming calls
• Test VoIP on real devices — simulators don't support push notifications

Sample App Reference

• This sample demonstrates standalone calling without VoIP
• For VoIP integration, add push notification handling and system call UI