{
  "$schema": "http://json-schema.org/draft-04/schema#",

  "type": "object",
  "required": ["meta"],
  "properties": {
    "meta": {
      "required": ["format_version"],
      "properties": {
        "format_version": {
          "type": "integer",
          "minimum": 1
        }
      },
      "additionalProperties": {
        "type": "object",
        "required": ["modified", "hostname"],
        "properties": {
          "modified": {
            "type": "string",
            "format": "date-time"
          },
          "hostname": {
            "type": "string",
            "format": "hostname"
          }
        }
      }
    }
  }
}