{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "#/components/schemas/Hub",
  "title": "Hub",
  "type": "object",
  "description": "Sets the communication endpoint address the service instance must use to deliver notification information",
  "allOf": [
    {
      "$ref": "#/components/schemas/Entity"
    },
    {
      "properties": {
        "id": {
          "type": "string",
          "description": "Id of the listener"
        },
        "callback": {
          "type": "string",
          "description": "The callback being registered."
        },
        "query": {
          "type": "string",
          "description": "additional data to be passed"
        }
      },
      "required": [
        "callback"
      ]
    }
  ]
}