Sub-Application routes are not shown in root routes

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• I already read and followed all the tutorial in the docs and didn’t find an answer.
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• 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.

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Example Code

# From the docs : https://fastapi.tiangolo.com/advanced/sub-applications/
from fastapi import FastAPI

app = FastAPI()


@app.get("/app")
def read_main():
    return {"message": "Hello World from main app"}


subapi = FastAPI()


@subapi.get("/sub")
def read_sub():
    return {"message": "Hello World from sub API"}


app.mount("/subapi", subapi)

Description

The sub Apis routes are not shown in the root docs.

I’m adding dynamically multiple sub Apis in my root app and it’s hard to keep track of which is mounted and on which names.

Is there a way to show at least the name of the sub API route in the root app?

Example Docs at the root :

/app # (exists) Description of  /app route in root
/subapi # (Do not exists) Description of /subapi (at least to know another app is mounted)

Nother Exemple of Docs at the root :

/app # Description of  /app route in root
# SubApi Tag to know there is another app 
/docs # Know that there is docs inside subapp
/sub  # Know that there is sub route inside sub app

Operating System

Linux

Operating System Details

Archlinux Kernel 5.13.10

FastAPI Version

0.66.0

Python Version

3.9.6

Additional Context

Thanks for this beautiful library !

[frerikandriessen]

I would also like to have an overview of all the mounted routes on the root docs. Is this something FastAPI is willing to accept a PR for?

[kauedg]

I’ve been using subapps to manage different API versions and these versions are listed by a “information” endpoint.

import starlette
from fastapi import FastAPI, Request
from versions import v0, v1

class ApiInfo(object):
    """docstring for ApiInfo."""

    def __init__(
        self,
        app: FastAPI,
        request: Request):

        super(ApiInfo, self).__init__()

        self.url = str(request.url)

        self.autodocs = {
            'swagger': str(request.url) + app.docs_url.strip("/"),
            'redoc': str(request.url) + app.redoc_url.strip("/"),
        }

        # Gera a lista de versões
        self.versions = {}
        for version in app.routes:
            if type(versions) is starlette.routing.Mount:
                self.versions[version.name] =  str(request.url) + version.name


app = FastAPI(
    title="Root app",
)

app.mount("/v0", v0.app, "v0")
app.mount("/v1", v1.app, "v1")

@app.get(
   '/',
   summary='API Information',
   tags=['API'],
)
def info(
   request: Request,
):
   apiInfo = ApiInfo(app, request)

   apiInfo.versions['stable'] = apiInfo.versions['v0']
   apiInfo.versions['develop'] = apiInfo.versions['v1']
   # whatever other label/mount name you want
   
   return apiInfo.__dict__

It will return something like this

{
  "url": "http://192.168.0.20:8686/",
  "versions": {
    "v0": "http://192.168.0.20:8686/v0",
    "v1": "http://192.168.0.20:8686/v1",
    "stable": "http://192.168.0.20:8686/v0"
    "develop": "http://192.168.0.20:8686/v1"
  },
  "autodocs": {
    "swagger": "http://192.168.0.20:8686/docs",
    "redoc": "http://192.168.0.20:8686/redoc"
  }
}