Invoke a Callback When a Group is Full

Last updated: 2020-03-24 16:40:09


Feature Description

The app backend can use this callback to monitor whether the number of members in a group has reached the limit for the group. This callback can also be used to delete inactive group members to accept new members.


  • To enable this callback, you must configure the callback URL and toggle on the corresponding protocol. For details on the configuration method, see Third-Party Callback Configuration.
  • Callback direction: the IM backend initiates an HTTP POST request to the app backend.
  • After receiving the callback request, the app backend must check whether the SDKAppID contained in the request URL is consistent with its own SDKAppID.
  • For other security-related issues, see Third-Party Callback Overview: Security Considerations.

Callback Triggering Scenarios

  • An app user requests to join a group through the client.
  • An app user is invited to join a group through the client.
  • The app admin adds a member to the group through a RESTful API.

Callback Triggering Time

The callback is triggered when the number of group members reaches the limit for the group after a new member is added, or when a new member fails to be added to a group because the number of group members has reached the limit.

API Description

Request URL example

In the following example, the callback URL configured in the app is

Request parameters

Parameter Description
https The request protocol is HTTPS, and the request method is POST. The callback URL.
SdkAppid The SDKAppID assigned by the IM console when an app is created.
CallbackCommand The value is fixed to Group.CallbackAfterGroupFull.
contenttype The value is fixed to JSON.
ClientIP The client IP address, whose format is similar to
OptPlatform The client platform. For details on the possible values, see the OptPlatform parameter in Third-Party Callback Overview: Callback Protocols.

Request packet example

    "CallbackCommand": "Group.CallbackAfterGroupFull", // Callback command
    "GroupId": "@TGS#2J4SZEAEL" // Group ID

Request packet fields

Field Type Description
CallbackCommand String The callback command.
GroupId String The ID of the group that is full.

Response packet example

After detecting that the number of group members has reached the limit, the app backend sends a callback response packet.

    "ActionStatus": "OK",
    "ErrorInfo": "",
    "ErrorCode": 0 // The result in the response is ignored.

Response packet fields

Field Type Attribute Description
ActionStatus String Required The request processing result. OK: succeeded. FAIL: failed.
ErrorCode Integer Required The error code. 0: ignore the result in the response.
ErrorInfo String Required Error information.