[joakimnordling]

FastAPI 0.146.0 deprecates the root_path parameter of FastAPI() in favour of configuring the server, e.g. fastapi run --root-path /api/v1. Our test_root_path used that parameter, so it now emits a FastAPIDeprecationWarning (a UserWarning, so it isn't hidden by our ignore::DeprecationWarning filter).

Changes

• test_root_path now gets its root_path from the server (TestClient(app, root_path="/api/v1")), the way fastapi run --root-path does. The deprecated parameter only ever set that same scope value, so the library code path is unchanged.
• The test now also checks that the static files load from under /api/v1/..., which it didn't before.
• The locked FastAPI goes from 0.143.0 to 0.146.0.

No library code changes; the fastapi>=0.133.0,<1 range stays as it is.

FastAPI releases reviewed

0.143.4, 0.143.5, 0.144.0, 0.145.0 and 0.146.0 came out on 2026-10-18. Only two touch what we use:

• 0.145.0 removes the deprecated openapi_prefix parameter and **extra. We use neither.
• 0.146.0 deprecates the root_path parameter (above).

The docs routes still call get_swagger_ui_html / get_redoc_html from fastapi.applications with an openapi_url built from the request's root_path, so the patching keeps working unchanged.

Testing

uv run invoke test passes (pre-commit, mypy, 15 tests with no warnings, uv audit).

CI only tests the locked FastAPI version, so I also checked the docs HTML and static files with a server-provided root_path by hand on FastAPI 0.133.0 + Starlette 0.40.0, 0.133.0 + 1.7.0, 0.138.0 + 0.46.0, 0.143.0 + 1.7.0 and 0.146.0 + 1.7.0. All passed.

🤖 Generated with Claude Code

[joakimnordling]

Superseded by #14, which includes these changes together with the Swagger UI 5.33.3 update, the dev tool updates and the 0.3.1 version bump.