Configuration

pyproject.toml

The repository's single source of project configuration. Notable sections:

Section	Purpose
[project]	Package metadata. requires-python = ">=3.10". Runtime dependencies: starlette>=0.46.0, pydantic>=2.9.0, typing-extensions>=4.8.0, typing-inspection>=0.4.2, annotated-doc>=0.0.2.
[project.optional-dependencies]	Three opt-in groups installed as pip install fastapi[standard] etc.: standard, standard-no-fastapi-cloud-cli, all.
[project.scripts]	Single entry: fastapi = fastapi.cli:main.
[dependency-groups]	Dev-time groups (PEP 735): dev, tests, docs, docs-tests, github-actions, translations.
[tool.pdm]	Build version source: fastapi/__init__.py.
[tool.mypy]	strict = true; uses pydantic.mypy plugin. Per-module overrides relax docs_src and tests.
[tool.pytest]	minversion = "9.0"; addopts = ["--strict-config", "--strict-markers", "--ignore=docs_src"]; filterwarnings = ["error"]; timeout = "20".
[tool.coverage.run]	parallel = true, source = ["docs_src", "tests", "fastapi"]. Excludes benchmarks and a few intentionally untested tutorials.
[tool.ruff.lint]	select = ["E","W","F","I","B","C4","UP"]. Per-file ignores call out tutorial examples that intentionally show "wrong" code.
[tool.ruff.lint.isort]	known-third-party = ["fastapi", "pydantic", "starlette"].
[tool.inline-snapshot]	Currently empty — defaults are applied per pytest invocation.

FastAPI(...) runtime configuration

The FastAPI constructor accepts roughly forty parameters. The headline ones:

Parameter	Default	What it does
title, version, summary, description, terms_of_service, contact, license_info	"FastAPI", "0.1.0", …	OpenAPI info metadata.
openapi_url	"/openapi.json"	Path of the schema route. None to disable.
docs_url	"/docs"	Swagger UI path. None to disable.
redoc_url	"/redoc"	ReDoc path. None to disable.
swagger_ui_oauth2_redirect_url	"/docs/oauth2-redirect"	OAuth2 redirect bridge.
swagger_ui_init_oauth	None	Dict passed to Swagger UI's initOAuth(...).
swagger_ui_parameters	None	Extra Swagger UI config merged onto the defaults.
default_response_class	JSONResponse	Class used to wrap returned values.
dependencies	None	List of dependencies applied to every route.
responses	None	Dict of OpenAPI response shapes applied to every route.
redirect_slashes	True	Inherit from Starlette.
generate_unique_id_function	generate_unique_id (fastapi/utils.py)	OpenAPI operation-ID generator.
lifespan	None	Async context manager replacing on_startup/on_shutdown.
webhooks	None	Routes describing outbound webhooks (OpenAPI only).
separate_input_output_schemas	True	Toggle separate request/response schemas.
terms_of_service, contact, license_info, openapi_tags	None	OpenAPI metadata.

For the full list with documentation, read the docstrings in fastapi/applications.py — every parameter is annotated with Annotated[T, Doc("""...""")].

CI environment

.github/workflows/test.yml and the doc-build workflows expect:

• UV_SYSTEM_PYTHON set to enable uv sync against the system Python on CI runners.
• GITHUB_TOKEN for bot-driven workflows (people.yml, sponsors.yml, latest-changes.yml, etc.).

There are no other repository-level configuration files (no .env, no separate config). The MkDocs setup lives under docs/<lang>/mkdocs.yml, generated by scripts/docs.py.