Feature Description

This API is used by the app backend to monitor users' group messages in real time, including:

• Records group messages in real time, for example, by recording a log or synchronizing the messages to other systems.
• Blocks users' requests to send messages in a group.
• Modifies users' message content, for example, by filtering out sensitive words or adding custom information defined by the app.

Notes:

• To enable this callback, you must configure the callback URL and enable the corresponding switch for this callback. For more information on the configuration method, see Callback Configuration.
• During this callback, 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 the SDKAppID of the app.
• For more security considerations, see the Security Considerations section of Third-Party Callback Overview.

Callback Trigger Scenarios

• An app user sends a group message on the client.
• The app admin sends a group message via a RESTful API call.

Callback Trigger Time

The callback is triggered before the IM backend sends a group message to group members.

API Description

Sample request URL

In the following sample, the callback URL configured in the app is https://www.example.com.
Sample:

https://www.example.com?SdkAppid=$SDKAppID&CallbackCommand=$CallbackCommand&contenttype=json&ClientIP=$ClientIP&OptPlatform=$OptPlatform

Request parameters

Sample request packet

{
    "CallbackCommand": "Group.CallbackBeforeSendMsg", // Callback command
    "GroupId": "@TGS#2J4SZEAEL", // Group ID
    "Type": "Public", // Group type
    "From_Account": "jared", // Sender
    "Operator_Account":"admin", // Request initiator
    "Random": 123456, // Random number
    "MsgBody": [ // Message body. For more information, see the `TIMMessage` message object.
        {
            "MsgType": "TIMTextElem", // Text
            "MsgContent": {
                "Text": "red packet"
            }
        }
    ]
}

Request packet fields

Sample response packet

Allowing group message sending

The user is allowed to send group messages, and the content of the sent message is not modified.

{
    "ActionStatus": "OK",
    "ErrorInfo": "",
    "ErrorCode": 0 // The value `0` indicates the user is allowed to send group messages.
}

Forbidding group message sending

The user is not allowed to send group messages. In this case, the message is not sent, and the error code 10016 is returned to the caller.

{
    "ActionStatus": "OK",
    "ErrorInfo": "",
    "ErrorCode": 1 // The value `1` indicates that the user is not allowed to send group messages.
}

Discarding messages silently

The user is not allowed to send group messages. In this case, the message is not sent, but a success message will be returned to the caller to pretend that the message has been sent.

{
    "ActionStatus": "OK",
    "ErrorInfo": "",
    "ErrorCode": 2 // The value `2` indicates the message is silently discarded.
}

Modifying message content

In the following response sample, the group message sent by the user is modified (a custom message is added), and the IM backend will send the modified message. With this feature, the app backend can add special content, such as the user level and title, to the message sent by the user.

{
    "ActionStatus": "OK",
    "ErrorInfo": "",
    "ErrorCode": 0, // This field must be set to `0` so that the modified message can be sent normally.
    "MsgBody": [ // Message modified by the app backend. If the app backend does not modify the message, the message sent by the user is used by default.
        {
            "MsgType": "TIMTextElem", // Text
            "MsgContent": {
                "Text": "red packet"
            }
        },
        {
            "MsgType": "TIMCustomElem", // Custom message
            "MsgContent": {
                "Desc": "CustomElement.MemberLevel", // Description
                "Data": "LV1" // Data
            }
        }
    ]
}

Response packet fields

References

• Third-Party Callback Overview
• RESTful API: Sending Ordinary Messages in a Group