> This page is for SDKs, version Legacy.
> For other versions, use one of these documentation indexes:
> - Current (default): https://buildwithfern.com/learn/sdks/current/llms.txt
> - Legacy: https://buildwithfern.com/learn/sdks/legacy/llms.txt

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

## 3.37.0

**`(feat):`** Add `additionalProperty(String key, Object value)` and `additionalProperties(Map<String, Object>)`
methods to generated builders, allowing users to set arbitrary extra fields programmatically.
Previously, additional properties were only populated during JSON deserialization.