# struct Ensures that your API document conforms to the [OpenAPI specification](https://spec.openapis.org/arazzo/latest.html#arazzo-specification). | Arzzo | Compatibility | | --- | --- | | 1.x | ✅ | The default setting for this rule (in the `recommended` and `minimal` configuration) is `error`. This is an essential rule. Do not turned it off, except in rare and special cases. ## Configuration | Option | Type | Description | | --- | --- | --- | | severity | string | Possible values: `off`, `warn`, `error`. Default `error` (in `recommended` configuration). | An example configuration: ```yaml rules: struct: error ```