Changelog¶

All notable changes to this project are documented here.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

0.4.1 — 2026-07-29¶

No functional changes: the library behaves exactly as in 0.4.0.

The docstrings of the public API were substantially expanded — they now spell out the until resolution rules, the build-once behaviour and the diagnostics, and they are what your IDE shows on hover. The same docstrings back the new auto-generated API reference.
Package metadata: keywords filled in, Homepage repointed from the repository to the documentation site, and Issues / Changelog URLs added.
The build backend requirement was widened to uv_build>=0.8.3,<0.12.0.

WebSocket routes are versioned on par with HTTP ones: APIWebSocketRoute is inherited between versions with the same until semantics, and shadowing is kind-aware — an HTTP route and a WebSocket on the same path never conflict.
api_version and until are validated. A non-int (or bool) api_version and an until below the declaring version now emit a UserWarning instead of failing silently.
API_VERSION_KEY is exported from the package root.

Breaking. The middleware was rewritten as plain ASGI middleware (no BaseHTTPMiddleware) and builds the inheritance exactly once — on the first ASGI event. Routes or versions added after that need an explicit rebuild_versioning(app), which is now public.
Breaking. Every inheriting version receives its own copy of the route, with dependency_overrides bound to the target application, instead of sharing a single route object between versions.
Breaking. Version metadata is stored per route in a registry on the version sub-application, rather than by mutating the shared dependency instance. A router included into several versions now resolves correctly.
Python 3.9 support dropped; the supported range is 3.10–3.14.

FastAPI 0.137+ is supported: routes are walked through the public iter_route_contexts iterator of the new router tree, so endpoints added with include_router are versioned together with their include-time prefixes and dependencies. FastAPI 0.137.0 and 0.137.1 are excluded at the dependency level — the tree landed there but the public iterator only in 0.137.2.
Version 0 is treated as a valid version (explicit None checks instead of truthiness).
An application that mounts no versioned sub-app is a graceful no-op instead of raising.

The rebuild_openapi flag on VersioningMiddleware. With False the endpoints are still inherited and served, but inherited ones do not appear in the version's OpenAPI schema and /docs.

First release: VersioningMiddleware and the versioning() dependency — one FastAPI sub-application per version, inheritance of marked endpoints from older versions into newer ones, and a regenerated OpenAPI schema per version.