> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://buildwithfern.com/learn/llms.txt. ## 5.15.2 **`(fix):`** Fix `ImportError` when a type uses `extends` to inherit from a base type that is part of a circular reference cycle (e.g. `Acai extends Berry` where `Berry → Animal → Cat → Fruit → Acai`). Python inheritance requires a top-level import of the base class, which cannot coexist with the ghost reference imports needed for circular forward-ref resolution. The generator now automatically falls back to inlining the base type's properties instead of using Python class inheritance when it detects a circular extends chain. **`(fix):`** When a custom `httpx.Client` or `httpx.AsyncClient` is passed to the generated SDK client, the timeout configured on that httpx client is now respected. Previously, the SDK would extract only the `read` timeout component and pass it explicitly to each request, which overrode the full timeout configuration (including separate connect/read/write/pool timeouts). Now, when no explicit `timeout` is provided to the SDK constructor, requests defer to the httpx client's own timeout settings via `httpx.USE_CLIENT_DEFAULT`. ## 5.15.1 **`(fix):`** Fix pydantic-v2 generator failing to find `.gitignore.Template` at runtime by copying the `asIs` directory into the dist bundle. **`(fix):`** Fix pydantic-v2 WrappedAliasGenerator producing invalid Python: add missing `self` parameter to getter methods, use correct return type instead of hardcoded `UUID`, quote forward-reference return types in builder methods, and add missing `return` statement in builder method bodies.