{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "description": "An Ditto Protocol ACK/NACK is sent in response to an event.",
  "title": "Ditto Protocol acknowledgement",
  "properties": {
    "topic": {
      "type": "string",
      "description": "Contains the topic of the acknowledgement, ending with the acknowledgement label."
    },
    "headers": {
      "type": "object",
      "description": "Additional headers.",
      "properties": {
        "correlation-id": {
          "type": "string",
          "description": "The correlation-id header is used for linking the acknowledgement to the event which requested it."
        },
        "version": {
          "type": "integer",
          "description": "Determines the schema version of the payload.",
          "minimum": 1,
          "maximum": 2
        }
      },
      "required": [ "correlation-id" ]
    },
    "path": {
      "type": "string",
      "description": "The path is always the empty path `/` for an acknowledgement."
    },
    "value": {
      "type": ["object","string","number","array","boolean"],
      "description": "The _value_ field contains the optional payload of the acknowledgement."
    },
    "status": {
      "type": "integer",
      "description": "The status code that indicates the result of the acknowledgement. The semantics of the used status codes are based on the [HTTP status codes](https://tools.ietf.org/html/rfc7231#section-6)."
    }
  },
  "required": [ "topic", "headers", "path", "status" ]
}