{
  "id": "transaction.sync",
  "type": "object",
  "required": ["data"],
  "properties": {
    "data": {
      "type": "object",
      "required": ["id", "type", "attributes"],
      "properties": {
        "type": {
          "type": "string",
          "constant": "agreement"
        },
        "attributes": {
          "type": "object",
          "required": ["id"],
          "properties": {
            "id": { "type": "string", "minLength": 1 },
            "start": { "type": "string", "format": "date-time" },
            "end": { "type": "string", "format": "date-time" }
          }
        }
      }
    }
  }
}