Join A Group

AI Integration Quick Reference

// Join a public group
CometChat.joinGroup("GROUP_GUID", CometChatGroupType.public,
  onSuccess: (Group group) => debugPrint("Joined: ${group.name}"),
  onError: (CometChatException e) => debugPrint("Error: ${e.message}"),
);

// Join a password-protected group
CometChat.joinGroup("GROUP_GUID", CometChatGroupType.password,
  password: "group_password",
  onSuccess: (Group group) => debugPrint("Joined: ${group.name}"),
  onError: (CometChatException e) => debugPrint("Error: ${e.message}"),
);

Group types: CometChatGroupType.public | CometChatGroupType.password | CometChatGroupType.private

Join a group to start sending and receiving messages in it. Public groups can be joined freely, password groups require the correct password, and private groups require an admin to add you (no direct join).

Use joinGroup() to join a group.

Available via: SDK | REST API | UI Kits

Parameters

Parameter	Type	Description
`guid`	`String`	The GUID of the group to join
`groupType`	`String`	`CometChatGroupType.public`, `CometChatGroupType.password`, or `CometChatGroupType.private`
`password`	`String`	Required for password-protected groups (defaults to empty string)
`onSuccess`	`Function(Group group)?`	Callback triggered on successful join
`onError`	`Function(CometChatException excep)?`	Callback triggered on error

Dart

String GUID = "GUID";
String groupType = CometChatGroupType.public;
String password = "";

CometChat.joinGroup(GUID, groupType, password: password,
                  onSuccess: (Group group) {
                    debugPrint("Group Joined Successfully : $group ");
                  }, onError: (CometChatException e) {
                    debugPrint("Group Joining failed with exception: ${e.message}");
  });

Response

On Success — A Group object containing all details of the joined group:Group Object:

Parameter	Type	Description	Sample Value
`guid`	string	Unique identifier for the group	`"cometchat-guid-1"`
`name`	string	Display name of the group	`"Hello Group!"`
`icon`	string	URL of the group icon	`null`
`description`	string	Description of the group	`null`
`membersCount`	number	Number of members in the group	`5`
`metadata`	object	Custom metadata attached to the group	`{}`
`joinedAt`	number	Epoch timestamp when the logged-in user joined the group	`1745554729`
`hasJoined`	boolean	Whether the logged-in user has joined the group	`true`
`createdAt`	number	Epoch timestamp when the group was created	`1745551200`
`owner`	string	UID of the group owner	`"cometchat-uid-1"`
`updatedAt`	number	Epoch timestamp when the group was last updated	`1745554729`
`tags`	array	List of tags associated with the group	`[]`
`type`	string	Type of the group (public, private, password)	`"public"`
`scope`	string	Scope of the logged-in user in the group	`"participant"`
`password`	string	Password for password-protected groups	`null`
`isBannedFromGroup`	boolean	Whether the logged-in user is banned from the group	`false`

Error

Parameter	Type	Description	Sample Value
`code`	string	Error code identifier	`"ERR_GUID_NOT_FOUND"`
`message`	string	Human-readable error message	`"The specified group does not exist."`
`details`	string	Additional technical details	`"Please provide a valid GUID for the group."`

Once joined, you can send and receive messages in the group. CometChat tracks joined groups — you don’t need to rejoin each session. Check hasJoined on the Group object to verify membership.

Real-time Group Member Joined Events

In other words, as a member of a group, how do I know if someone joins the group when my app is running? If a user joins any group, the members of the group receive a real-time event in the onGroupMemberJoined() method of the GroupListener class.

Dart

class ClassName with GroupListener {
  // CometChat.addGroupListener("group_Listener_id", this);

  @override
  void onGroupMemberJoined(Action action, User joinedUser, Group joinedGroup) {
    debugPrint("onGroupMemberJoined");
  }
}

Always remove group listeners when they’re no longer needed (e.g., in dispose()). Failing to remove listeners can cause memory leaks and duplicate event handling.

CometChat.removeGroupListener("group_Listener_id");

Missed Group Member Joined Events

In other words, as a member of a group, how do I know if someone joins the group when my app is not running? When you retrieve the list of previous messages if a member has joined any group that the logged-in user is a member of, the list of messages will contain an Action message. An Action message is a sub-class of BaseMessage class. For the group member joined event, in the Action object received, the following fields can help you get the relevant information-

action - joined
actionBy - User object containing the details of the user who joined the group
actionFor- Group object containing the details of the group the user has joined

Next Steps

Leave a Group

Allow members to leave a group

Retrieve Group Members

Fetch the list of members in a group

Send Messages

Send messages to group conversations

Add Members

Programmatically add members to a group

​Join a Group

​Parameters

​Real-time Group Member Joined Events

​Missed Group Member Joined Events

​Next Steps

Leave a Group

Retrieve Group Members

Send Messages

Add Members

Join a Group

Parameters

Real-time Group Member Joined Events

Missed Group Member Joined Events

Next Steps