Topic

{
  "type": "object",
  "properties": {
    "base64_message": {
      "type": "string"
    },
    "message": {
      "type": "string"
    },
    "topic_name": {
      "type": "string"
    }
  },
  "required": [
    "topic_name"
  ],
  "additionalProperties": false
}