FastAPI Standalone Docs

Host FastAPI Swagger UI and ReDoc without any third party CDNs. Handy if you want to be able to use the docs offline or want to avoid loading content from 3rd party CDNs due to privacy reasons.

This library was heavily inspired by fastapi-offline-swagger-ui, but we wanted a way to take it into use with less boilerplate code and also have it hosted on PyPI.

Installation

The package is available on PyPI:

pip install fastapi-standalone-docs

Usage

Import StandaloneDocs and pass in the FastAPI application to it:

from fastapi import FastAPI
from fastapi_standalone_docs import StandaloneDocs

app = FastAPI()
StandaloneDocs(app=app)

The static files will by default be served from subpaths of the docs_url and redoc_url as you've specified in your FastAPI app. The library doesn't make any assumption on any particular path being reserved for the library. And if you disable either of the two UIs, the corresponding files won't either be served unnecessarily.

This example would move the Swagger UI and the static files needed for it to the path /swagger and disable the ReDoc interface and the static files needed by it:

from fastapi import FastAPI
from fastapi_standalone_docs import StandaloneDocs

app = FastAPI(docs_url="/swagger", redoc_url=None)
StandaloneDocs(app=app)

By default, the library will use the FastAPI favicons, and they're served from {docs_url}/fastapi/favicon.png and {redoc_url}/fastapi/favicon.png. You can use your own favicons like this, which will also disable the FastAPI icons:

from fastapi import FastAPI
from fastapi_standalone_docs import StandaloneDocs

app = FastAPI()
StandaloneDocs(
    app=app,
    redoc_favicon_url="/favicon.png",
    swagger_favicon_url="/favicon.png",
)

To make the docs truly stand alone the Google Fonts are by default disabled (they are used in the ReDoc interface). If you want to enable them just set with_google_fonts=True, like this:

from fastapi import FastAPI
from fastapi_standalone_docs import StandaloneDocs

app = FastAPI()
StandaloneDocs(
    app=app,
    with_google_fonts=True,
)

Disclaimer

Note! If you create multiple FastAPI apps in the same runtime (quite unlikely use-case), for example by mounting one app inside another, using StandaloneDocs on one of them will affect the other ones as well, as the library patches two of the shared functions (get_swagger_ui_html and get_redoc_html). Thus, the library should not be used in such a setup unless all the apps will use StandaloneDocs with the same settings and the same docs_url, redoc_url and openapi_url on the FastAPI app itself. If any of those differ, only the app that called StandaloneDocs last will serve its docs correctly.

Development

PRs are welcome!

This project is using uv, so please ensure you've installed it. To set up the project run:

uv sync
uv run pre-commit install

Running tests locally (pre-commit hooks, mypy, pytest and a dependency audit):

uv run invoke test

Updating the static files from the CDNs:

uv run update-fastapi-standalone-docs

If you want to test using it locally in some other project, in that project run this (make sure to adjust the path to the local repo):

uv add --editable ../fastapi-standalone-docs

License

The code of this library itself is released under the MIT license. Please however note that this library also contains parts of ReDoc, which is licensed under the MIT license, Swagger UI, which is licensed under the Apache 2.0 License, as well as parts of FastAPI (the favicon), which is licensed under the MIT license.