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

## 1.9.12

**`(fix):`** Change serialization logic for headers and querystring parameters:

* Strings, enums, dates, times, and date times are serialized as before.
* Booleans are now serialized as `true` and `false` instead of `True` and `False`.
* Objects, lists, maps, dictionaries, undiscriminated, and discriminated unions are serialized to JSON.

**`(fix):`** Only use `.Value` on nullable structs when serializing parameters to headers and querystring parameters.