{

"$schema": "http://json-schema.org/draft-07/schema",
"definitions": {
  "url_verification": {
    "type": "object",
    "description": "learn more: https://api.slack.com/events/url_verification",
    "properties": {
      "challenge": {
        "type": "string"
      },
      "token": {
        "type": "string"
      },
      "type": {
        "const": "url_verification"
      }
    },
    "example": {
      "challenge": "3eZbrw1aBm2rZgRNFdxV2595E9CY3gmdALWMmHkvFXO7tYXAYM8P",
      "token": "Jhj5dZrVaK7ZwHHjRyZWjbDl",
      "type": "url_verification"
    }
  }
}

}