{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "version": {
      "oneOf": [
        {
          "type": "string",
          "minLength": 1,
          "maxLength": 255
        },
        {
          "type": "null"
        }
      ]
    },
    "slug": {
      "type": "string",
      "minLength": 4,
      "maxLength": 63,
      "pattern": "^[0-9a-z-]*$"
    }
  },
  "additionalProperties": false,
  "required": [
    "slug"
  ]
}