{
  "type": "object",
  "required": ["v", "type", "ts", "deviceId", "payload"],
  "properties": {
    "v": {
      "type": "integer",
      "description": "Protocol version"
    },

    "type": {
      "type": "string",
      "description": "Message type"
    },

    "ts": {
      "type": "integer",
      "description": "Unix time in milliseconds"
    },

    "deviceId": {
      "type": "string",
      "minLength": 1,
      "description": "Unique device identifier"
    },

    "payload": {
      "type": "object",
      "description": "Message-specific data"
    }
  }
}