You can submit up to 10 messages in a single request, but you must always encapsulate the messages in a collection container (an array in JSON, even for a single message - without the JSON array, you receive the "Invalid request body" message). The resulting value of the Location header or response body might be used to retrieve the created messages for further processing.

The client specifies only the body and TTL for the message. The server inserts metadata, such as ID and age.

See a sample as below:

[
  {
    "body": {
      "event": "BackupProgress",
      "current_bytes": "2341134",
      "total_bytes": "99614720"
    }
  }
]