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Quick Reference - Initiate a call and listen for events:
Available via: SDK | REST API | UI Kits

Overview

This section explains how to implement a complete calling workflow with ringing functionality, including incoming/outgoing call UI, call acceptance, rejection, and cancellation. Previously known as Default Calling.
After the call is accepted, you need to start the call session. See the Call Session guide for details on starting and managing the actual call.
Call Flow:
  1. Caller initiates a call using initiateCall()
  2. Receiver gets notified via onIncomingCallReceived() callback
  3. Receiver can either:
    • Accept the call using acceptCall()
    • Reject the call using rejectCall() with status CALL_STATUS_REJECTED
  4. Caller can cancel the call using rejectCall() with status CALL_STATUS_CANCELLED
  5. Once accepted, both participants generate a call token and render the CometChatCalls.Component to join the call

Initiate Call

The initiateCall() method sends a call request to a user or a group. On success, the receiver gets an onIncomingCallReceived() callback.
On success, a Call object is returned containing the call details including a unique sessionId required for starting the call session. By default, an unanswered call automatically cancels after 45 seconds. You can customize this duration by passing an optional timeout parameter (in seconds) as the second argument to initiateCall().
On SuccessinitiateCall() returns a Call object with session details:User Object Structure:

Call Listeners

Register the CallListener to receive real-time call events. Each listener requires a unique listenerId string to prevent duplicate registrations and enable targeted removal.
Always remove call listeners when the component unmounts using CometChat.removeCallListener(listenerId). Failing to do so can cause memory leaks and duplicate event handling.

Events

On EventonIncomingCallReceived returns a Call object (same structure as initiateCall response):
On EventonOutgoingCallRejected / onIncomingCallCancelled returns a Call object with status: "unanswered":
On EventonOutgoingCallAccepted returns a Call object with status: "ongoing":
On EventonCallEndedMessageReceived returns a Call object with status: "ended":User Object Structure:

Accept Call

When an incoming call is received via onIncomingCallReceived(), use acceptCall() to accept it. On success, start the call session.
On SuccessacceptCall() returns a Call object with status: "ongoing":User Object Structure:

Reject Call

Use rejectCall() to reject an incoming call. Set the status to CALL_STATUS_REJECTED.
On SuccessrejectCall() with REJECTED status returns a Call object:User Object Structure:

Cancel Call

The caller can cancel an outgoing call before it’s answered using rejectCall() with status CALL_STATUS_CANCELLED.
On SuccessrejectCall() with CANCELLED status returns a Call object:User Object Structure:

Start Call Session

Once the call is accepted, both participants need to start the call session. Caller flow: In the onOutgoingCallAccepted() callback, generate a token and start the session. Receiver flow: In the acceptCall() success callback, generate a token and start the session.
On SuccessgenerateToken() returns an object with session and token:
On EventonUserJoined returns user info when a participant joins:
On EventonUserListUpdated returns the current list of participants:Each participant object:
On EventonUserLeft returns user info when a participant leaves:
For more details on call settings and customization, see the Call Session guide.

End Call

To end an active call in the ringing flow, the process differs based on who ends the call. User who ends the call: When the user presses the end call button, the onCallEndButtonPressed() callback is triggered. Inside this callback, call CometChat.endCall() to notify other participants. On success, call CometChat.clearActiveCall() and CometChatCalls.endSession() to release resources.
Remote participant (receives onCallEnded() callback):
On SuccessendCall() returns a Call object with status: "ended":User Object Structure:
For more details, see the End Call Session guide.

Busy Call Handling

If the receiver is already on another call, you can reject the incoming call with CALL_STATUS_BUSY status.
On SuccessrejectCall() with BUSY status returns a Call object:
On Event — The caller receives onOutgoingCallRejected with status: "busy":User Object Structure:
  • Always remove call listeners on component unmount to prevent memory leaks and duplicate events
  • Store the sessionId from initiateCall() or onIncomingCallReceived() — you’ll need it for accept, reject, cancel, and starting the session
  • Handle the CALL_STATUS_BUSY case when the receiver is already on another call
  • Call CometChat.clearActiveCall() and CometChatCalls.endSession() together when a call ends to properly release all resources
  • Request camera and microphone permissions before initiating or accepting a call
  • Show appropriate UI feedback (spinner, ringing animation) while waiting for the receiver to respond
  • onIncomingCallReceived not firing: Ensure CometChat.addCallListener() is registered before the call is initiated and that the listener ID is unique
  • Call accepted but no audio/video: After acceptCall(), you must start the call session by generating a token and rendering CometChatCalls.Component — see the Start Call Session section above
  • Duplicate call events: You may have registered the same listener multiple times — always call CometChat.removeCallListener(listenerId) on unmount
  • initiateCall fails with error: Verify the receiver UID/GUID exists and that the logged-in user has an active session
  • Call ends immediately after accept: Make sure both caller and receiver generate a call token and render CometChatCalls.Component — if only one side renders the component, the call will appear to drop
  • Busy status not working: Ensure you’re using CometChat.CALL_STATUS.BUSY (not REJECTED) when the receiver is already on a call

Next Steps

Call Session

Start and manage the actual call session after the ringing flow completes.

Calls SDK Setup

Install dependencies, configure permissions, and initialize the Calls SDK.

Recording

Record audio and video calls for playback or compliance.

Call Logs

Retrieve and display call history including duration and participants.