{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "description": "An Ditto Protocol announcement announces an event before it actually happens.",
  "title": "Ditto Protocol announcement",
  "properties": {
    "topic": {
      "type": "string",
      "description": "Contains the topic of the announcement, ending with the announcement name."
    },
    "headers": {
      "type": "object",
      "description": "Additional headers."
    },
    "path": {
      "type": "string",
      "description": "The path is always the empty path `/` for an announcement."
    },
    "value": {
      "type": ["object","string","number","array","boolean"],
      "description": "The _value_ field contains the optional payload of the announcement."
    }
  },
  "required": [ "topic", "headers", "path" ]
}