* Add support for setting a `default_response_class` in the `FastAPI` instance or in `include_router`. Initial PR [#467](https://github.com/tiangolo/fastapi/pull/467) by [@toppk](https://github.com/toppk).
* Add support for type annotations using strings and `from __future__ import annotations`. PR [#451](https://github.com/tiangolo/fastapi/pull/451) by [@dmontagu](https://github.com/dmontagu).