Join A Group

Learn how to join public and password-protected groups using the CometChat Flutter SDK.

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).

Join a Group

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-

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

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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