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Webhooks/
One-to-One Message Webhooks/
Before a One-to-One Message Is Sent/

Before a One-to-One Message Is Sent

Overview

This webhook is used by the app backend to manage users' one-to-one messages in real time, including:
Records one-to-one messages sent in real time, for example, by recording a log or synchronizing the messages to other systems.
Blocks users' requests to send non-compliant messages of any type, such as text, image, and custom messages.
Note:
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.

Limits

To enable this webhook, you must configure the 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 HTTPS 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.
If the webhook before sending one-to-one messages and the webhook after sending one-to-one messages are both enabled and forbidding message sending is returned for the webhook before sending one-to-one messages, the webhook after sending one-to-one messages cannot be triggered.
If the webhook before sending one-to-one messages and the webhook after sending one-to-one messages are both enabled and the message body is modified during the webhook before sending one-to-one messages, the webhook after sending one-to-one messages will use the modified message for webhook.
For more security considerations, see the Security Considerations section in Webhook Overview.

Webhook Triggering Scenarios

An app user sends a one-to-one message on the client.
The app admin sends a one-to-one message by calling the sendmsg RESTful API.

Webhook Triggering Timing

The Chat backend has received a one-to-one message sent by a user but has not delivered the message to the target user.

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](http://www.example.com)
Callback URL
SdkAppid
The SDKAppID assigned by the Chat console when the app is created
CallbackCommand
The value is always C2C.CallbackBeforeSendMsg.
contenttype
Always 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 Overview.

Sample requests

{
    "CallbackCommand": "C2C.CallbackBeforeSendMsg", // Webhook command
    "From_Account": "jared", // Sender
    "To_Account": "John", // Recipient
    "MsgSeq": 48374, // Sequence number of the message
    "MsgRandom": 2837546, // Random number of the message
    "MsgTime": 1557481126, // Timestamp in seconds indicating when the message is sent 
    "MsgKey": "48374_2837546_1557481126", // Unique identifier of the message. It can be used to recall the message via a RESTful API call.
    "OnlineOnlyFlag":1, // The value is `1` if it is an online message and `0` if it's not
    "MsgBody": [ // Message body. For more information, see the `TIMMessage` message object.
        {
            "MsgType": "TIMTextElem", // Text
            "MsgContent":{
                "Text": "red packet"
            }
        }
    ],
    "CloudCustomData": "your cloud custom data"
}

Request fields

Field
Type
Description
CallbackCommand
String
Webhook command
From_Account
String
UserID of the message sender
To_Account
String
UserID of the message recipient
MsgSeq
Integer
Sequence number of the message. It is used to identify the message and the value is a random 32-bit unsigned integer.
MsgRandom
Integer
Random number of the message. It is used to identify the message and the value is a random 32-bit unsigned integer.
MsgTime
Integer
Timestamp in seconds indicating when the message is sent.
One-to-one messages are preferentially sorted by MsgTime.
Messages sent in the same second are sorted by MsgSeq.
Messages with larger values of MsgSeq are after those with smaller values.
MsgKey
String
Unique identifier of the message. It can be used to recall the message via a RESTful API call.
OnlineOnlyFlag
Integer
The value is 1 if it is an online message and 0 if it's not.
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.

Sample response when sending messages is allowed

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.
}

Sample response when sending messages is forbidden

The user is not allowed to send group messages. In this case, the message is not sent, and the error code 20006 is returned to the user (message sender).
{
    "ActionStatus": "OK",
    "ErrorInfo": "",
    "ErrorCode": 1 // `1` indicates that the user is not allowed to send messages.
}

Sample response when messages are discarded 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 sender.
{
    "ActionStatus": "OK",
    "ErrorInfo": "",
    "ErrorCode": 2 // The value `2` indicates the message is silently discarded.
}

Sample response when the message content is modified

In the following sample, the message sent by the user is modified (a custom message or custom message data 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. Example:
{
    "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 new cloud custom data" // Custom message data
}

Response fields

Field
Type
Required
Description
ActionStatus
String
Yes
Request result. OK: Successful; FAIL: Failed
ErrorCode
Integer
Yes
Error code returned. 0: allows message sending; 1: forbids message sending; 2: discards the message silently. If the business side wants to forbid a user to send messages and send ErrorCode and ErrorInfo to the client, ensure that the value of ErrorCode is set within the range of [120001, 130000].
ErrorInfo
String
Yes
Error information
MsgBody
Array
No
Message body modified by the app backend. The Chat backend sends the modified message to the recipient. For more information on the format, see Message Formats.
CloudCustomData
String
No
Custom message data modified by the app backend. 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. The Chat backend sends the modified message to the recipient.

References

Webhook Overview
After One-to-One Message Is Sent
Sending One-to-One Messages to One User
Sending One-to-One Messages to Multiple Users