{
  "msgClass": 4,
  "date": "2020-04-13T20:23:00+01:00",
  "retain": true,
  "payload": {...}
}

Messages sent via the WAMP router are given this wrapper.

Description

• msgClass: Required. Identifies the type of message contained in payload. One of the constant values defined in the MessageClass enum.
• date: Required. Date of transmission of the message.
• retain: Boolean. Routing information working around a bug in Crossbar; when true, tells relay servers to rebroadcast this message with the retain WAMP publish option.
• payload: Required. The message content, as defined by the appropriate message class definition.