- Added type hints on all major interfaces
- Deprecated `App.run`
- Deprecated string signals in favour of `extensions.Signals`
- Removed `libs.sanitizer`
- Use `orjson` for JSON serialization
- Refactored request flow internals
- Added namespaces to templater
- Added `SameSite` support to session cookies
- Added HTTP/2 support
- Added `Request.push_promise`
- Added Python 3.9 support (beta)