> This page is for Fern CLI.

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

## 0.78.6

**`(fix):`** Support `null` in an `enum` (functionality is delegated to `nullable<>`).

## 0.78.5

**`(fix):`** Correct `nullable<>` wrapping of nullable schemas referenced via `$ref`.

## 0.78.4

**`(fix):`** Collapse any combination of optional and nullable to `optional<nullable<T>>`.

## 0.78.3

**`(chore):`** Support IR v59 in the Rust SDK generator.