All Real Time Listeners - CometChat Docs

CometChat provides 4 listeners viz.

UserListener
GroupListener
MessageListener
AIAssistantListener

User Listener

The UserListener class provides you with live events related to users. Below are the callback methods provided by the UserListener class.

Method	Information
`onUserOnline(User user)`	This method is triggered when a user comes online and is available to chat. The details of the user can be obtained from the user object received as the method parameter.
`onUserOffline(User user)`	This method is triggered when a user goes offline. The details of the user can be obtained from the User object received as the parameter.

To add the UserListener, you need to use the addUserListener() method provided by the CometChat class.

Dart

class Class_Name with UserListener {
  //CometChat.addUserListener("user_Listener_id", this);
	@override
  void onUserOnline(User user) {

  }

  @override
  void onUserOffline(User user) {

  }

}

where UNIQUE_LISTENER_ID is the unique identifier for the listener. Please make sure that no two listeners are added with the same listener id as this could lead to unexpected behavior resulting in loss of events. Once the activity/fragment where the UserListener is declared is not in use, you need to remove the listener using the removeUserListener() method which takes the id of the listener to be removed as the parameter. We suggest you call this method in the onPause() method of the activity/fragment.

Dart

CometChat.removeUserListener(UNIQUE_LISTENER_ID)

Group Listener

The GroupListener class provides you with all the real-time events related to groups. Below are the callback methods provided by the GroupListener class.

Method	Information
`onGroupMemberJoined(Action action, User joinedUser, Group joinedGroup)`	This method is triggered when a user joins any group. All the members present in the group will receive this event.
`onGroupMemberLeft(Action action, User leftUser, Group leftGroup)`	This method is triggered when a user who was a member of any group leaves the group. All the members of the group receive this event.
`onGroupMemberKicked(Action action, User kickedUser, User kickedBy, Group kickedFrom)`	This method is triggered when a user is kicked from a group. All the members including the user receive this event
`onGroupMemberBanned(Action action, User bannedUser, User bannedBy, Group bannedFrom)`	This method is triggered when a user is banned from a group. All the members including the user receive this event
`onGroupMemberUnbanned(Action action, User unbannedUser, User unbannedBy, Group unbannedFrom)`	This method is triggered when a user is banned from a group. All the members of the group receive this event.
`onGroupMemberScopeChanged(Action action, User updatedBy, User updatedUser, String scopeChangedTo, String scopeChangedFrom, Group group)`	This method is triggered when the scope of any Group Member has been changed. All the members that are a part of that group receive this event
`onMemberAddedToGroup(Action action, User addedBy, User userAdded, Group addedTo)`	This method is triggered when a user is added to any group. All the members including the user himself receive this event.

To add the GroupListener, you need to use the addGroupListener() method provided by the CometChat class.

Dart

class Class_Name with GroupListener {
  //CometChat.addGroupListener("UNIQUE_LISTENER_ID", this);

  @override
  void onGroupMemberJoined(Action action, User joinedUser, Group joinedGroup) {

  }

  @override
  void onGroupMemberLeft(Action action, User leftUser, Group leftGroup) {

  }

  @override
  void onGroupMemberKicked(Action action, User kickedUser, User kickedBy, Group kickedFrom) {

  }

  @override
  void onGroupMemberBanned(Action action, User bannedUser, User bannedBy, Group bannedFrom) {

  }

  @override
  void onGroupMemberUnbanned(Action action, User unbannedUser, User unbannedBy, Group unbannedFrom) {

  }

  @override
  void onGroupMemberScopeChanged(Action action, User updatedBy, User updatedUser, String scopeChangedTo, String scopeChangedFrom, Group group) {

  }

  @override
  void onMemberAddedToGroup(Action action, User addedby, User userAdded, Group addedTo) {

  }

}

where UNIQUE_LISTENER_ID is the unique identifier for the listener. Please make sure that no two listeners are added with the same listener id as this could lead to unexpected behavior resulting in loss of events. Once the activity/fragment where the GroupListener is declared is not in use, you need to remove the listener using the removeGroupListener() method which takes the id of the listener to be removed as the parameter. We suggest you call this method in the onPause() method of the activity/fragment.

Dart

CometChat.removeGroupListener(UNIQUE_LISTENER_ID)

Message Listener

The MessageListener class provides you with live events related to messages. Below are the callback methods provided by the MessageListener class.

Method	Information
`onTextMessageReceived(TextMessage message)`	This event is triggered when a Text Message is received.
`onMediaMessageReceived(MediaMessage message)`	This event is triggered when a Media Message is received.
`onCustomMessageReceived(CustomMessage message)`	This event is triggered when a Custom Message is received.
`onTypingStarted(TypingIndicator typingIndicator)`	This event is triggered when a user starts typing in a user/group conversation
`onTypingEnded(TypingIndicator typingIndicator)`	This event is triggered when a user stops typing in a user/group conversation.
`onMessagesDelivered(MessageReceipt messageReceipt)`	This event is triggered when a set of messages are marked as delivered for any particular conversation.
`onMessagesRead(MessageReceipt messageReceipt)`	This event is triggered when a set of messages are marked as read for any particular conversation.
`onMessageEdited(BaseMessage message)`	This method is triggered when a particular message has been edited in a user/group conversation.
`onMessageDeleted(BaseMessage message)`	This event is triggered when a particular message is deleted in a user/group conversation.
`onInteractiveMessageReceived(InteractiveMessage message)`	This event is triggered when an Interactive Message is received.
`onCardMessageReceived(CardMessage message)`	This event is triggered when a Card Message is received.
`onInteractionGoalCompleted(InteractionReceipt receipt)`	This event is triggered when an interaction Goal is achieved.
`onTransientMessageReceived(TransientMessage transientMessage)`	This event is triggered when a Transient Message is received.
`onMessageReactionAdded(ReactionEvent reactionEvent)`	This event is triggered when a reaction is added to a message in a user/group conversation.
`onMessageReactionRemoved(ReactionEvent reactionEvent)`	This event is triggered when a reaction is remove from a message in a user/group conversation.
`onAIAssistantMessageReceived(AIAssistantMessage message)`	This event is triggered when a persisted AI Assistant message is received after a run completes.
`onAIToolResultReceived(AIToolResultMessage message)`	This event is triggered when an AI tool result message is received.
`onAIToolArgumentsReceived(AIToolArgumentMessage message)`	This event is triggered when AI tool argument messages are received.

To add the MessageListener, you need to use the addMessageListener() method provided by the CometChat class.

Dart

class Class_Name with MessageListener {

  //CometChat.addMessageListener("listenerId", this);
	@override
  void onTextMessageReceived(TextMessage textMessage) {

  }

  @override
  void onMediaMessageReceived(MediaMessage mediaMessage) {

  }

  @override
  void onCustomMessageReceived(CustomMessage customMessage) {

  }

    @override
  void onTypingStarted(TypingIndicator typingIndicator) {

  }

  @override
  void onTypingEnded(TypingIndicator typingIndicator) {

  }

  @override
  void onMessagesDelivered(MessageReceipt messageReceipt) {

  }

  @override
  void onMessagesRead(MessageReceipt messageReceipt) {

  }

  @override
  void onMessageEdited(BaseMessage message) {

  }

  @override
  void onMessageDeleted(BaseMessage message) {

  }

  @override
  void onInteractionGoalCompleted(InteractionReceipt receipt) {

  }

  @override
  void onInteractiveMessageReceived(InteractiveMessage message) {

  }

  @override
  void onCardMessageReceived(CardMessage cardMessage) {

  }

  @override
  void onTransientMessageReceived(TransientMessage transientMessage) {

  }

  @override
  void onMessageReactionAdded(ReactionEvent reactionEvent) {

  }

  @override
  void onMessageReactionRemoved(ReactionEvent reactionEvent) {

  }

  @override
  void onAIAssistantMessageReceived(AIAssistantMessage aiAssistantMessage) {

  }

  @override
  void onAIToolResultReceived(AIToolResultMessage aiToolResultMessage) {

  }

  @override
  void onAIToolArgumentsReceived(AIToolArgumentMessage aiToolArgumentMessage) {

  }

}

where UNIQUE_LISTENER_ID is the unique identifier for the listener. Please make sure that no two listeners are added with the same listener id as this could lead to unexpected behavior resulting in loss of events. Once the activity/fragment where the MessageListener is declared is not in use, you need to remove the listener using the removeMessageListener() method which takes the id of the listener to be removed as the parameter. We suggest you call this method in the onPause() method of the activity/fragment.

AI Assistant Listener

The AIAssistantListener class provides you with real-time streaming events from AI Agent runs. These events are emitted during a run lifecycle and include tool calls, card generation, and text message streaming. For a complete overview of the event lifecycle, see AI Agents.

Method	Information
`onAIAssistantEventReceived(AIAssistantBaseEvent event)`	This event is triggered for every AI assistant streaming event during a run (run start/finish, tool calls, card generation, text streaming).

To add the AIAssistantListener, use the addAIAssistantListener() method provided by the CometChat class.

Dart

class Class_Name with AIAssistantListener {
  CometChat.addAIAssistantListener("UNIQUE_LISTENER_ID", this);

  @override
  void onAIAssistantEventReceived(AIAssistantBaseEvent event) {
    // Handle different event types
    if (event is AIAssistantRunStartedEvent) {
      debugPrint("Run started: ${event.id}");
    } else if (event is AIAssistantToolStartedEvent) {
      debugPrint("Tool call started");
    } else if (event is AIAssistantCardStartedEvent) {
      debugPrint("Card generation started: ${event.cardId}");
    } else if (event is AIAssistantCardReceivedEvent) {
      final cardPayload = event.getCard();
      debugPrint("Card received: ${event.cardId}");
    } else if (event is AIAssistantCardEndedEvent) {
      debugPrint("Card ended: ${event.cardId}");
    } else if (event is AIAssistantContentReceivedEvent) {
      debugPrint("Streaming content delta: ${event.delta}");
    } else if (event is AIAssistantMessageEndedEvent) {
      debugPrint("Message streaming ended");
    } else if (event is AIAssistantRunFinishedEvent) {
      debugPrint("Run finished: ${event.id}");
    }
  }
}

To remove the listener:

Dart

CometChat.removeAIAssistantListener("UNIQUE_LISTENER_ID");

The AIAssistantListener delivers real-time streaming events. After a run completes, persisted agentic messages (AIAssistantMessage, AIToolResultMessage, AIToolArgumentMessage) are delivered via the MessageListener callbacks listed above.

​User Listener

​Group Listener

​Message Listener

​AI Assistant Listener

User Listener

Group Listener

Message Listener

AI Assistant Listener