Standalone Calling - CometChat Docs

Overview

This section demonstrates how to implement calling functionality using only the CometChat Calls SDK, without requiring the Chat SDK. This is ideal for applications that need video/audio calling capabilities without the full chat infrastructure.

Before you begin, ensure you have completed the Calls SDK setup.

User Authentication

To start a call session, you need a user auth token. Since this implementation doesn’t use the Chat SDK, you’ll need to obtain the auth token via the CometChat REST API.

To understand user authentication in CometChat, see the User Auth documentation.

You can obtain the auth token using one of these REST API endpoints:

Create Auth Token — Creates a new auth token for a user
Get Auth Token — Retrieves an existing auth token

For testing or POC purposes, you can create an auth token directly from the CometChat Dashboard. Navigate to Users & Groups → Users, select a user, and click + Create Auth Token.

Store the auth token securely in your application for use when generating call tokens.

Generate Call Token

A call token is required for secure access to a call session. Each token is unique to a specific session and user combination, ensuring that only authorized users can join the call. You can generate the token just before starting the call, or generate and store it ahead of time based on your use case. Use the generateToken() method to create a call token:

JavaScript
TypeScript

const sessionId = "UNIQUE_SESSION_ID"; // Generate a unique session ID
const userAuthToken = "USER_AUTH_TOKEN"; // Obtained from REST API

CometChatCalls.generateToken(sessionId, userAuthToken).then(
  (callToken) => {
    console.log("Call token generated:", callToken.token);
    // Use callToken to start the session
  },
  (error) => {
    console.log("Token generation failed:", error);
  }
);

const sessionId: string = "UNIQUE_SESSION_ID"; // Generate a unique session ID
const userAuthToken: string = "USER_AUTH_TOKEN"; // Obtained from REST API

CometChatCalls.generateToken(sessionId, userAuthToken).then(
  (callToken: any) => {
    console.log("Call token generated:", callToken.token);
    // Use callToken to start the session
  },
  (error: any) => {
    console.log("Token generation failed:", error);
  }
);

Parameter	Description
`sessionId`	A unique session ID for the call. Generate this yourself or use a shared ID for participants to join the same call.
`userAuthToken`	The user auth token obtained from the CometChat REST API.

Start Call Session

Use the startSession() method to join a call session. This method requires:

A call token (generated in the previous step)
A CallSettings object that configures the call UI and behavior
An HTML element where the call UI will be rendered

JavaScript
TypeScript

const callListener = new CometChatCalls.OngoingCallListener({
  onUserJoined: (user) => {
    console.log("User joined:", user);
  },
  onUserLeft: (user) => {
    console.log("User left:", user);
  },
  onUserListUpdated: (userList) => {
    console.log("User list updated:", userList);
  },
  onCallEnded: () => {
    console.log("Call ended");
    CometChatCalls.endSession();
    // Close calling screen
  },
  onCallEndButtonPressed: () => {
    console.log("End call button pressed");
    CometChatCalls.endSession();
    // Close calling screen
  },
  onError: (error) => {
    console.log("Call error:", error);
  },
  onMediaDeviceListUpdated: (deviceList) => {
    console.log("Device list updated:", deviceList);
  },
  onUserMuted: (event) => {
    console.log("User muted:", event);
  },
  onScreenShareStarted: () => {
    console.log("Screen sharing started");
  },
  onScreenShareStopped: () => {
    console.log("Screen sharing stopped");
  },
  onCallSwitchedToVideo: (event) => {
    console.log("Call switched to video:", event);
  },
  onSessionTimeout: () => {
    console.log("Session timed out");
  }
});

const callSettings = new CometChatCalls.CallSettingsBuilder()
  .enableDefaultLayout(true)
  .setIsAudioOnlyCall(false)
  .setCallListener(callListener)
  .build();

const htmlElement = document.getElementById("call-container");
CometChatCalls.startSession(callToken, callSettings, htmlElement);

const callListener = new CometChatCalls.OngoingCallListener({
  onUserJoined: (user: any) => {
    console.log("User joined:", user);
  },
  onUserLeft: (user: any) => {
    console.log("User left:", user);
  },
  onUserListUpdated: (userList: any[]) => {
    console.log("User list updated:", userList);
  },
  onCallEnded: () => {
    console.log("Call ended");
    CometChatCalls.endSession();
    // Close calling screen
  },
  onCallEndButtonPressed: () => {
    console.log("End call button pressed");
    CometChatCalls.endSession();
    // Close calling screen
  },
  onError: (error: any) => {
    console.log("Call error:", error);
  },
  onMediaDeviceListUpdated: (deviceList: any[]) => {
    console.log("Device list updated:", deviceList);
  },
  onUserMuted: (event: any) => {
    console.log("User muted:", event);
  },
  onScreenShareStarted: () => {
    console.log("Screen sharing started");
  },
  onScreenShareStopped: () => {
    console.log("Screen sharing stopped");
  },
  onCallSwitchedToVideo: (event: any) => {
    console.log("Call switched to video:", event);
  },
  onSessionTimeout: () => {
    console.log("Session timed out");
  }
});

const callSettings = new CometChatCalls.CallSettingsBuilder()
  .enableDefaultLayout(true)
  .setIsAudioOnlyCall(false)
  .setCallListener(callListener)
  .build();

const htmlElement = document.getElementById("call-container") as HTMLElement;
CometChatCalls.startSession(callToken, callSettings, htmlElement);

Parameter	Description
`callToken`	The token received from `generateToken()` onSuccess
`callSettings`	Object of `CallSettings` class configured via `CallSettingsBuilder`
`htmlElement`	DOM element where the call UI will be rendered

Call Settings

Configure the call experience using the following CallSettingsBuilder methods:

Method	Description
`enableDefaultLayout(boolean)`	Enables or disables the default call UI layout with built-in controls. `true` shows the default layout. `false` hides the button layout. Default: `true`
`setIsAudioOnlyCall(boolean)`	Sets whether the call is audio-only or audio-video. `true` for audio-only, `false` for audio-video. Default: `false`
`setCallListener(OngoingCallListener)`	Sets the listener to receive call events. See Call Listeners.
`setMode(string)`	Sets the call UI layout mode. Available: `CometChat.CALL_MODE.DEFAULT`, `CometChat.CALL_MODE.SPOTLIGHT`. Default: `DEFAULT`
`startWithAudioMuted(boolean)`	Starts the call with the microphone muted. Default: `false`
`startWithVideoMuted(boolean)`	Starts the call with the camera turned off. Default: `false`
`showEndCallButton(boolean)`	Shows or hides the end call button in the default layout. Default: `true`
`showMuteAudioButton(boolean)`	Shows or hides the mute audio button. Default: `true`
`showPauseVideoButton(boolean)`	Shows or hides the pause video button. Default: `true`
`showScreenShareButton(boolean)`	Shows or hides the screen share button. Default: `true`
`showModeButton(boolean)`	Shows or hides the mode toggle button (switch between DEFAULT and SPOTLIGHT). Default: `true`
`showSwitchToVideoCallButton(boolean)`	Shows or hides the button to upgrade an audio call to video. Default: `true`
`setMainVideoContainerSetting(MainVideoContainerSetting)`	Customizes the main video container. See Video View Customization.
`setIdleTimeoutPeriod(number)`	Sets idle timeout in seconds. Warning appears 60 seconds before auto-termination. Default: `180` seconds. v4.1.0+

Call Listeners

The OngoingCallListener provides real-time callbacks for call session events, including participant changes, call state updates, and error conditions. You can register listeners in two ways:

Via CallSettingsBuilder: Use .setCallListener(listener) when building call settings
Via addCallEventListener: Use CometChatCalls.addCallEventListener(listenerId, listener) to add multiple listeners

Each listener requires a unique listenerId string. This ID is used to:

Prevent duplicate registrations — Re-registering with the same ID replaces the existing listener
Enable targeted removal — Remove specific listeners without affecting others

JavaScript
TypeScript

const listenerId = "UNIQUE_LISTENER_ID";

CometChatCalls.addCallEventListener(listenerId, {
  onUserJoined: (user) => {
    console.log("User joined:", user);
  },
  onUserLeft: (user) => {
    console.log("User left:", user);
  },
  onUserListUpdated: (userList) => {
    console.log("User list updated:", userList);
  },
  onCallEnded: () => {
    console.log("Call ended");
    CometChatCalls.endSession();
    // Close calling screen
  },
  onCallEndButtonPressed: () => {
    console.log("End call button pressed");
    CometChatCalls.endSession();
    // Close calling screen
  },
  onError: (error) => {
    console.log("Call error:", error);
  },
  onMediaDeviceListUpdated: (deviceList) => {
    console.log("Device list updated:", deviceList);
  },
  onUserMuted: (event) => {
    console.log("User muted:", event);
  },
  onScreenShareStarted: () => {
    console.log("Screen sharing started");
  },
  onScreenShareStopped: () => {
    console.log("Screen sharing stopped");
  },
  onCallSwitchedToVideo: (event) => {
    console.log("Call switched to video:", event);
  },
  onSessionTimeout: () => {
    console.log("Session timed out");
  }
});

// Remove listener when done
CometChatCalls.removeCallEventListener(listenerId);

const listenerId: string = "UNIQUE_LISTENER_ID";

CometChatCalls.addCallEventListener(listenerId, {
  onUserJoined: (user: any) => {
    console.log("User joined:", user);
  },
  onUserLeft: (user: any) => {
    console.log("User left:", user);
  },
  onUserListUpdated: (userList: any[]) => {
    console.log("User list updated:", userList);
  },
  onCallEnded: () => {
    console.log("Call ended");
    CometChatCalls.endSession();
    // Close calling screen
  },
  onCallEndButtonPressed: () => {
    console.log("End call button pressed");
    CometChatCalls.endSession();
    // Close calling screen
  },
  onError: (error: any) => {
    console.log("Call error:", error);
  },
  onMediaDeviceListUpdated: (deviceList: any[]) => {
    console.log("Device list updated:", deviceList);
  },
  onUserMuted: (event: any) => {
    console.log("User muted:", event);
  },
  onScreenShareStarted: () => {
    console.log("Screen sharing started");
  },
  onScreenShareStopped: () => {
    console.log("Screen sharing stopped");
  },
  onCallSwitchedToVideo: (event: any) => {
    console.log("Call switched to video:", event);
  },
  onSessionTimeout: () => {
    console.log("Session timed out");
  }
});

// Remove listener when done
CometChatCalls.removeCallEventListener(listenerId);

Events

Event	Description
`onCallEnded()`	Invoked when the call session terminates for a 1:1 call. Both participants receive this callback. Only fires for calls with exactly 2 participants.
`onSessionTimeout()`	Invoked when the call is auto-terminated due to inactivity (default: 180 seconds). Warning appears 60 seconds before. v4.1.0+
`onCallEndButtonPressed()`	Invoked when the local user clicks the end call button. Call `CometChatCalls.endSession()` to leave the session.
`onUserJoined(user)`	Invoked when a remote participant joins. The `user` contains UID, name, and avatar.
`onUserLeft(user)`	Invoked when a remote participant leaves the call session.
`onUserListUpdated(userList)`	Invoked whenever the participant list changes (join or leave events).
`onMediaDeviceListUpdated(deviceList)`	Invoked when available audio/video devices change (e.g., new microphone connected).
`onUserMuted(event)`	Invoked when a participant’s mute state changes. Contains `muted` and `mutedBy` properties.
`onScreenShareStarted()`	Invoked when the local user starts sharing their screen.
`onScreenShareStopped()`	Invoked when the local user stops sharing their screen.
`onCallSwitchedToVideo(event)`	Invoked when an audio call is upgraded to a video call. Contains `sessionId`, `initiator`, and `responder`.
`onError(error)`	Invoked when an error occurs during the call session.

End Call Session

To end the call session and release all media resources (camera, microphone, network connections), call CometChatCalls.endSession() in the onCallEndButtonPressed() callback.

JavaScript
TypeScript

onCallEndButtonPressed: () => {
  CometChatCalls.endSession();
  // Close the calling screen
}

onCallEndButtonPressed: () => {
  CometChatCalls.endSession();
  // Close the calling screen
}

Methods

These methods are available for performing custom actions during an active call session. Use them to build custom UI controls or implement specific behaviors based on your use case.

These methods can only be called when a call session is active.

Switch Camera

Toggles between the front and rear camera during a video call. Only supported on mobile browsers.

JavaScript
TypeScript

CometChatCalls.switchCamera();

CometChatCalls.switchCamera();

This method is only supported on mobile browsers. It has no effect on desktop browsers. Available since v4.2.0

Mute Audio

Controls the local audio stream transmission. When muted, other participants cannot hear the local user.

true — Mutes the microphone, stops transmitting audio
false — Unmutes the microphone, resumes audio transmission

JavaScript
TypeScript

CometChatCalls.muteAudio(true);

CometChatCalls.muteAudio(true);

Pause Video

Controls the local video stream transmission. When paused, other participants see a frozen frame or placeholder instead of live video.

true — Pauses the camera, stops transmitting video
false — Resumes the camera, continues video transmission

JavaScript
TypeScript

CometChatCalls.pauseVideo(true);

CometChatCalls.pauseVideo(true);

Starts sharing your screen or a specific application window with other participants.

JavaScript
TypeScript

CometChatCalls.startScreenShare();

CometChatCalls.startScreenShare();

Stops the current screen sharing session.

JavaScript
TypeScript

CometChatCalls.stopScreenShare();

CometChatCalls.stopScreenShare();

Set Mode

Changes the call UI layout mode dynamically during the call. Available modes:

CometChat.CALL_MODE.DEFAULT — Grid layout showing all participants
CometChat.CALL_MODE.SPOTLIGHT — Focus on the active speaker

JavaScript
TypeScript

CometChatCalls.setMode(CometChat.CALL_MODE.SPOTLIGHT);

CometChatCalls.setMode(CometChat.CALL_MODE.SPOTLIGHT);

Get Audio Input Devices

Returns a list of available audio input devices (microphones).

JavaScript
TypeScript

const audioInputDevices = CometChatCalls.getAudioInputDevices();
console.log("Available microphones:", audioInputDevices);

const audioInputDevices = CometChatCalls.getAudioInputDevices();
console.log("Available microphones:", audioInputDevices);

Get Audio Output Devices

Returns a list of available audio output devices (speakers/headphones).

JavaScript
TypeScript

const audioOutputDevices = CometChatCalls.getAudioOutputDevices();
console.log("Available speakers:", audioOutputDevices);

const audioOutputDevices = CometChatCalls.getAudioOutputDevices();
console.log("Available speakers:", audioOutputDevices);

Get Video Input Devices

Returns a list of available video input devices (cameras).

JavaScript
TypeScript

const videoInputDevices = CometChatCalls.getVideoInputDevices();
console.log("Available cameras:", videoInputDevices);

const videoInputDevices = CometChatCalls.getVideoInputDevices();
console.log("Available cameras:", videoInputDevices);

Set Audio Input Device

Sets the active audio input device (microphone) by device ID.

JavaScript
TypeScript

CometChatCalls.setAudioInputDevice(deviceId);

CometChatCalls.setAudioInputDevice(deviceId);

Set Audio Output Device

Sets the active audio output device (speaker/headphones) by device ID.

JavaScript
TypeScript

CometChatCalls.setAudioOutputDevice(deviceId);

CometChatCalls.setAudioOutputDevice(deviceId);

Set Video Input Device

Sets the active video input device (camera) by device ID.

JavaScript
TypeScript

CometChatCalls.setVideoInputDevice(deviceId);

CometChatCalls.setVideoInputDevice(deviceId);

Switch To Video Call

Upgrades an ongoing audio call to a video call. This enables the camera and starts transmitting video to other participants. The remote participant receives the onCallSwitchedToVideo() callback.

JavaScript
TypeScript

CometChatCalls.switchToVideoCall();

CometChatCalls.switchToVideoCall();

End Call

Terminates the current call session and releases all media resources (camera, microphone, network connections). After calling this method, the call view should be closed.

JavaScript
TypeScript

CometChatCalls.endSession();

CometChatCalls.endSession();

​Overview

​User Authentication

​Generate Call Token

​Start Call Session

​Call Settings

​Call Listeners

​Events

​End Call Session

​Methods

​Switch Camera

​Mute Audio

​Pause Video

​Start Screen Share

​Stop Screen Share

​Set Mode

​Get Audio Input Devices

​Get Audio Output Devices

​Get Video Input Devices

​Set Audio Input Device

​Set Audio Output Device

​Set Video Input Device

​Switch To Video Call

​End Call

Overview

User Authentication

Generate Call Token

Start Call Session

Call Settings

Call Listeners

Events

End Call Session

Methods

Switch Camera

Mute Audio

Pause Video

Start Screen Share

Stop Screen Share

Set Mode

Get Audio Input Devices

Get Audio Output Devices

Get Video Input Devices

Set Audio Input Device

Set Audio Output Device

Set Video Input Device

Switch To Video Call

End Call