> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://buildwithfern.com/learn/llms.txt.

## 2.42.0

**`(feat):`** Add support for semantic distinction between `nullable<T>` and `optional<T>` types via `use-nullable-annotation` flag.
When enabled, `nullable<T>` generates as raw type `T` with `@Nullable` annotation, while `optional<T>` remains as `Optional<T>`.
This provides proper API semantics for fields that can be null vs those that may be absent from requests.

```yaml
customConfig:
  use-nullable-annotation: true
```