Before Group Message Is Sent

Feature Overview

This webhook event is used by the app backend to check 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.
Caution:
The timeout period of the webhook before message sending is two seconds by default, and we recommend you not adjust it. This webhook may time out when used for text moderation. If you need to moderate text, use the content webhook.

Limits

To enable this webhook, you must configure a webhook URL and enable the corresponding switch for this webhook. For more information on the configuration method, see Webhook Configuration.
During this webhook event, the Chat backend initiates an HTTP POST request to the app backend.
After receiving the webhook 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 in Webhook Overview.

Webhook Triggering Scenarios

An app user sends a group message on the client.
The app admin sends a group message via RESTful APIs.

Webhook Triggering Timing

The webhook is triggered before the Chat backend sends a group message to group members.

API Calling Description

Sample request URL

In the following sample, the webhook URL configured in the app is https://www.example.com. Example:
https://www.example.com?SdkAppid=$SDKAppID&CallbackCommand=$CallbackCommand&contenttype=json&ClientIP=$ClientIP&OptPlatform=$OptPlatform

Request parameters

Parameter
Description
https
The request protocol is HTTPS, and the request method is POST.
www.example.com
Webhook URL
SdkAppid
The SDKAppID assigned by the Chat console when the app is created
CallbackCommand
Fixed value: Group.CallbackBeforeSendMsg.
contenttype
Fixed value: JSON.
ClientIP
Client IP, such as 127.0.0.1
OptPlatform
Client platform. For valid values, see the description of OptPlatform in the Webhook Protocols section of Webhook Callback Overview.

Sample requests

{
"CallbackCommand": "Group.CallbackBeforeSendMsg", // Webhook command
"GroupId": "@TGS#2J4SZEAEL", // Group ID
"Type": "Community", // Group type
"From_Account": "jared", // Sender
"Operator_Account":"admin", // Request initiator
"Random": 123456, // Random number
"OnlineOnlyFlag": 1, // The value is `1` if it is an online message and `0` (default) if it’s not. For audio-video groups, the value is `0`.
"MsgBody": [ // Message body. For more information, see the `TIMMessage` message object.
{
"MsgType": "TIMTextElem", // Text
"MsgContent":{
"Text": "red packet"
}
}
],
"CloudCustomData": "your cloud custom data",
"TopicId":"@TGS#_@TGS#cQVLVHIM62CJ@TOPIC#_TestTopic",// Topic ID, which applies only to topic-enabled communities
"EventTime":"1670574414123"// Event trigger timestamp in milliseconds
}

Request fields

Field
Type
Description
CallbackCommand
String
Webhook command
GroupId
String
ID of the group that generates group messages
Type
String
Type of the group that generates group messages, such as Public. For details, see Group Types section in Group System.
From_Account
String
UserID of the message sender
Operator_Account
String
UserID of the request initiator, based on which the system can identify whether the request is initiated by the admin.
Random
Integer
A 32-bit random number in the request
OnlineOnlyFlag
Integer
The value is 1 if it is an online message and 0 (default) if it’s not. For audio-video groups, the value is 0.
MsgBody
Array
Message body. For more information, see Message Formats.
CloudCustomData
String
Custom message data. It is saved in the cloud and will be sent to the receiver. Such data can be pulled after the app is uninstalled and reinstalled.
TopicId
String
Topic ID, which indicates message sending in the topic and applies only to topic-enabled communities.
EventTime
Integer
Event trigger timestamp in milliseconds

Sample response

Allowing group message sending

The user is allowed to send group messages, and the content of the message is not modified.
{
"ActionStatus": "OK",
"ErrorInfo": "",
"ErrorCode": 0 // `0` indicates the user is allowed to send 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 // `1` indicates that the user is not allowed to send 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.
{
"ActionStatus": "OK",
"ErrorInfo": "",
"ErrorCode": 2 // The value `2` indicates the message is silently discarded.
}

Modifying the message content

In the following response sample, the group message sent by the user is modified (a custom message is added), and the Chat 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 delivered.
{
"MsgType": "TIMTextElem", // Text
"MsgContent":{
"Text": "red packet"
}
},
{
"MsgType": "TIMCustomElem", // Custom message
"MsgContent":{
"Desc": "CustomElement.MemberLevel", // Description
"Data": "LV1" // Data
}
}
],
"CloudCustomData": "your cloud custom data"
}

Response fields

Field
Type
Required
Description
ActionStatus
String
Yes
Request result. OK: Successful; FAIL: Failed
ErrorCode
Integer
Yes
Error code returned. 0: allows group message sending; 1: forbids group message sending; 2: discards the message silently. If the business side wants to forbid a user to send group messages and send ErrorCode and ErrorInfo to the client, ensure that the value of ErrorCode is set within the range of [10100, 10200].
ErrorInfo
String
Yes
Error information
MsgBody
Array
No
Message body modified by the app backend. The Chat backend sends the modified message to the group. For more information on the format, see Message Formats.
CloudCustomData
String
No
Custom message data. It is saved in the cloud and will be sent to the peer end. Such data can be pulled after the app is uninstalled and reinstalled.

References