starlette/docs/release-notes.md

0.6.1

Added support for BaseHTTPMiddleware, which provides a standard request/response interface over a regular ASGI middleware.

This means you can write ASGI middleware while still working at a request/response level, rather than handling ASGI messages directly.

from starlette.middleware.base import BaseHTTPMiddleware


class CustomMiddleware(BaseHTTPMiddleware):
    async def dispatch(self, request, call_next):
        response = await call_next(request)
        response.headers['Custom-Header'] = 'Example'
        return response

0.6.0

request.path_params

The biggest change in 0.6 is that endpoint signatures are no longer:

async def func(request: Request, **kwargs) -> Response

Instead we just use:

async def func(request: Request) -> Response

The path parameters are available on the request as request.path_params.

This is different to most Python webframeworks, but I think it actually ends up being much more nicely consistent all the way through.

request.url_for()

Request and WebSocketSession now support URL reversing with request.url_for(name, **path_params). This method returns a fully qualified URL instance. The URL instance is a string-like object.

app.url_path_for()

Applications now support URL path reversing with app.url_path_for(name, **path_params). This method returns a URL instance with the path and scheme set. The URL instance is a string-like object, and will return only the path if coerced to a string.

app.routes

Applications now support a .routes parameter, which returns a list of [Route|WebSocketRoute|Mount].

Route, WebSocketRoute, Mount

The low level components to Router now match the @app.route(), @app.websocket_route(), and app.mount() signatures.