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Event Callbacks

Last updated: 2022-06-08 16:52:29

    The event callback service can notify your server of TRTC events in the form of HTTP/HTTPS requests, including some events of the room and media event groups. To enable the service, you need to provide configuration information to Tencent Cloud.

    Configuration Information

    You can configure callback information in the TRTC console, and will receive event callback notifications after the configuration. For detailed directions, see Callback Configuration.


    You need to provide the following information:

    • Required: An HTTP/HTTPS server address to receive callback notifications
    • Optional: A custom key containing up to 32 uppercase and lowercase letters and digits, which is needed for the calculation of signatures

    Timeout and Retry

    A notification will be considered failed if the callback server does not receive a response from your server within 5 seconds of message sending. It will try again immediately after the first failure and retry 10 seconds after every subsequent failure. The retries will stop 1 minute after the first try.

    Format of Callback Messages

    Callbacks are sent to your server in the form of HTTP/HTTPS POST requests, which consist of the following parts:

    • Character encoding: UTF-8
    • Request: JSON for the request body
    • Response: HTTP STATUS CODE = 200. The server ignores the content of the response packet. For protocol-friendliness, we recommend adding JSON: {"code":0}` to the response.
    • Packet body sample: Below is an example of the packet body for room entry under the room event group.
      "EventGroupId": 1, #Room event group
      "EventType": 103, #Room entry event
      "CallbackTs": 1615554923704, #Callback time, in milliseconds
      "EventInfo": {
      "RoomId": 12345, #Numeric room number
      "EventTs": 1615554922, #Event occurrence time, in seconds
      "UserId": "test", #User ID
      "UniqueId": 1615554922656, #Unique identifier
      "Role": 20, #User role: Anchor
      "TerminalType": 3, #Device type: iOS
      "UserType": 3, #User type: Native SDK
      "Reason": 1 #Reason: Voluntary entry


    Callback message parameters

    • The header of a callback message contains the following fields.
    • The body of a callback message contains the following fields.
      EventGroupIdNumber Event group ID
      EventType Number Type of callback event
      CallbackTs Number Unix timestamp (ms) of callback sending
      EventInfo JSON Object Event information

    Event group ID

    Field Value Description
    EVENT_GROUP_ROOM 1 Room event group
    EVENT_GROUP_MEDIA 2 Media event group

    Event type

    Field Value Description
    EVENT_TYPE_CREATE_ROOM 101 Creating room
    EVENT_TYPE_DISMISS_ROOM 102 Closing room
    EVENT_TYPE_ENTER_ROOM 103 Entering room
    EVENT_TYPE_EXIT_ROOM 104 Leaving room
    EVENT_TYPE_CHANGE_ROLE 105 Switching roles
    EVENT_TYPE_START_VIDEO 201 Starting pushing video data
    EVENT_TYPE_STOP_VIDEO 202 Stopping pushing video data
    EVENT_TYPE_START_AUDIO 203 Starting pushing audio data
    EVENT_TYPE_STOP_AUDIO 204 Stopping pushing audio data
    EVENT_TYPE_START_ASSIT 205 Starting pushing substream data
    EVENT_TYPE_STOP_ASSIT 206 Stopping pushing substream data

    Event information

    Field Type Description
    RoomId String/Number Room ID, which is of the same type as the room ID on the client
    EventTs Number Unix timestamp (seconds) of event occurrence. This field is reserved for compatibility purposes.
    EventMsTs Number Unix timestamp (ms) of event occurrence
    UserId String User ID
    UniqueId Number Unique identifier, optional, carried by the room event group.
    When a user experiences unusual events such as network change or abnormal exit and reentry, your server may receive multiple callbacks for the entry and exit of the same user. A unique identifier helps identify that the multiple exits and entries are by the same user.
    Role Number Role type, optional, carried during room entry/exit
    TerminalType Number Device type, optional, carried during room entry
    UserType Number User type, optional, carried during room entry
    Reason Number Reason, optional, carried during room entry/exit

    We have developed a policy that prevents repeated callbacks resulting from unusual events on the client. If you start using the callback service after July 30, 2021, the policy will apply by default, and the room event group will no longer carry UniqueId.

    Role type

    Field Value Description
    MEMBER_TRTC_VIEWER 21 Audience

    Device type

    Field Value Description

    User type

    Field Value Description
    USER_TYPE_APPLET 2 Mini Program


    Field Description
    Room entry
  • 1: Voluntary entry
  • 2: Network change
  • 3: Timeout and retry
  • 4: Co-anchoring
  • Room exit
  • 1: Voluntary exit
  • 2: Timeout
  • 3: Removed from the room
  • 4: Co-anchoring was canceled.
  • 5: The process was force-killed.
    Note: TRTC cannot capture a force-kill event on Android and will send a callback only after timeout (reason = 2).
  • Signature calculation

    Signatures are calculated using the HMAC SHA256 encryption algorithm. Upon receiving a callback message, your server will calculate a signature using the same method, and if the results match, it indicates that the callback is from TRTC and not forged. See below for the calculation method.

    // In the formula below, `key` is the key used to calculate a signature.
    Sign = base64(hmacsha256(key, body))

    body is the original packet body of the callback request you receive. Do not make any modifications. Below is an example.


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