Double path to docs

[pow3rpi]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the FastAPI documentation, with the integrated search.
• I already searched in Google "How to X in FastAPI" and didn't find any information.
• I already read and followed all the tutorial in the docs and didn't find an answer.
• I already checked if it is not related to FastAPI but to Pydantic.
• I already checked if it is not related to FastAPI but to Swagger UI.
• I already checked if it is not related to FastAPI but to ReDoc.

Commit to Help

• I commit to help with one of those options 👆

Example Code

import uvicorn
from fastapi import FastAPI, APIRouter

router = APIRouter(prefix='/v1')


@router.get('/healthcheck', tags=['Healthcheck'])
def check_service():
    return {'status': 'OK'}


def create_app() -> FastAPI:
    api = FastAPI(
        title='Test App',
        root_path='/api',
        root_path_in_servers=False,
    )
    api.include_router(router)
    return api


app = create_app()

if __name__ == '__main__':
    uvicorn.run(
        'test:app',
        host='0.0.0.0',
        port=5000,
        reload=True
    )

Description

Actually, I am not sure if it is a FastAPI issue. It can be on the Swagger UI side but I haven't found any related issues in their repository, so that's why I've decided to open the discussion here.

The problem is that when I use root_path parameter in FastAPI application I get documentation accessible on 2 paths: default /docs and root_path+/docs.

Currently, I see 2 ways how I can handle this issue:

1. For example, use a different value for docs_url, like: docs_url='/docs-api', which is something I am not satisfied with.
   api = FastAPI(title='Test App', root_path='/api', root_path_in_servers=False, docs_url='/docs-api')
2. Change router prefix to /api/v1, remove root_path parameter and update docs_url with /api/docs. This is also not the best solution because each endpoint starts displaying /api/v1 prefix in swagger.
   router = APIRouter(prefix='/api/v1')
api = FastAPI(title='Test App', root_path_in_servers=False, docs_url='/api/docs')

Let me clarify that if I use:
api = FastAPI(title='Test App', root_path='/api', root_path_in_servers=False, docs_url='/api/docs')
then, swagger is accessible on very strange path /api/api/docs.

I reckon that it would be best to have opportunity to switch off default /docs path if we have root_path parameter specified. I don't insist that it should be a default setting but maybe we could control it via additional parameter.

Feel free to express your opinion on the topic.

Operating System

Linux

Operating System Details

No response

FastAPI Version

0.111.0

Pydantic Version

1.10.10

Python Version

3.11.9

Additional Context

No response

[YuriiMotov]

When you use root_path='/api' parameter in FastAPI() it will make all your endpoint accessible via two paths: 1) normal (http://localhost:5000/v1/healthcheck) and 2) prefixed (http://localhost:5000/api/v1/healthcheck).

As I understand this is done this way to make the app compatible with different ASGI servers (not sure about this).

To make it accessible by only normal paths you can remove that parameter from FastAPI() and pass it to uvicorn.run() (you should run your app behind the stripping path proxy, otherwise it will fail to show docs):

import uvicorn
from fastapi import FastAPI, APIRouter

router = APIRouter(prefix='/v1')


@router.get('/healthcheck', tags=['Healthcheck'])
def check_service():
    return {'status': 'OK'}


def create_app() -> FastAPI:
    api = FastAPI(
        title='Test App',
        # root_path='/api',
        root_path_in_servers=False,
    )
    api.include_router(router)
    return api


app = create_app()

if __name__ == '__main__':
    uvicorn.run(
        'test:app',
        host='0.0.0.0',
        port=5000,
        root_path="/api",
        reload=True
    )

Now, you /healthcheck endpoint will only be accessible via http://localhost:5000/v1/healthcheck (if you try requesting it directly from ASGI server). And from outside the proxy the path will be {host:port}/api/v1/healthcheck