> This page is for SDKs.

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

## 0.26.6

**`(chore):`** Make multi-variant enums forward-compatible by default with `__Unknown(String)` catch-all,
matching C#/TypeScript behavior. Single-variant enums (type discriminants used in
`#[serde(untagged)]` unions) remain strict to preserve correct variant dispatch.
Additionally, generate `#[serde(flatten)] pub extra: HashMap<String, serde_json::Value>`
on structs with `extraProperties` to capture unknown fields from the server.

## 0.26.5

**`(chore):`** Remove `Default` impl from `ApiClientBuilder` to improve forward compatibility.
The `..Default::default()` spread pattern on builder types can silently swallow
new required fields added in future versions. Removing `Default` ensures that
consumers are guided by the compiler to handle any new fields explicitly.
Updated README WebSocket snippets to use explicit `ClientConfig` construction
instead of the `..Default::default()` spread.

## 0.26.4

**`(chore):`** Add `Default` implementation for `ApiClientBuilder` and update README snippet generation
to use a simpler struct-based client initialization pattern with `ClientConfig { token: ..., ..Default::default() }`.