{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$defs": {
    "role": {
      "type": "string",
      "enum": [
        "admin",
        "member"
      ]
    },
    "userSpec": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "mailbox": {
          "type": "string",
          "pattern": "^[^@\\s]+$"
        },
        "role": {
          "$ref": "#/$defs/role"
        }
      },
      "required": [
        "mailbox"
      ]
    },
    "defaults": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "role": {
          "$ref": "#/$defs/role"
        }
      }
    }
  }
}