Hi, Welcome to FastAPI

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Hi,

OK, here is what I can add :

It seems this issue appeared when I've implemented the following code (but not sure...) :

class device_import(BaseModel):
    hostname: str
    ipaddress: str
    platform: str
    description: Optional[str] = None
......
@app.post("/system/device", summary="Create a new device in the system", tags=["System"])
async def post_device(device_info: device_import):
........

All other routes are using basic structure, with path parameters or Query.

In terms of imports :

from typing import Optional, Dict
from fastapi import FastAPI, Request, APIRouter, Form, Query, Body
from pydantic import BaseModel, Field

This issue appears each time I'm expanding a resource/API in the doc UI (Swagger UI).
Let's say that I click on a GET or a POST object to expand, I will automatically get the following log :
INFO: <IP>:49702 - "GET /%5Bobject%20Module%5D HTTP/1.1" 404 Not Found

As explained, the engine works, and I can launch every request, but I get this error, and I really don't what could be the root cause...

Thanks again,

your route is POST and it works fine.

......
@app.post("/system/device", summary="Create a new device in the system", tags=["System"])
async def post_device(device_info: device_import):
........

but your log is about GET request.
Request with GET/HEAD method cannot have body. check this out

from fastapi import Depends

@app.get("/system/device", summary="Create a new device in the system", tags=["System"])
async def post_device(device_info: device_import=Depends()):
    return device_info

Thanks a lot,

Just checked, and I've got the same issue even if I expand a GET, PUT or DELETE resource.
Let say that I click on this item to expand it, I'll get the log :

INFO: <IP>:51426 - "GET /%5Bobject%20Module%5D HTTP/1.1" 404 Not Found

Same thing if I do it on a POST item :

INFO: <IP>:51504 - "GET /%5Bobject%20Module%5D HTTP/1.1" 404 Not Found

I have the issue whatever the route and associated method I expand.
But if it has been expanded/loaded 1 time, I will never get the issue for it if I collapse/expand it, until I refresh the page (Which is quite obvious as content as been loaded...)

I also get the samme INFO message in my log

TRACE:    127.0.0.1:44588 - ASGI [10] Started scope={'type': 'http', 'asgi': {'version': '3.0', 'spec_version': '2.1'}, 'http_version': '1.1', 'server': ('127.0.0.1', 8000), 'client': ('127.0.0.1', 44588), 'scheme': 'http', 'method': 'GET', 'root_path': '', 'path': '/[object Module]', 'raw_path': b'/[object%20Module]', 'query_string': b'', 'headers': '<...>'}
TRACE:    127.0.0.1:44588 - ASGI [10] Send {'type': 'http.response.start', 'status': 404, 'headers': '<...>'}
INFO:     127.0.0.1:44588 - "GET /%5Bobject%20Module%5D HTTP/1.1" 404 Not Found

I'm having an identical issue to legalla - INFO: 127.0.0.1:58176 - "GET /%5Bobject%20Module%5D HTTP/1.1" 404 Not Found
Whenever I expand any method on the documentation. Also using ubuntu 18.04 - fastapi 0.63.0

I'm also running into the same issue, raised whenever I expand on an endpoint within the Swagger UI.

It's easy to reproduce - I have just cloned a git example repo using fast api, it seems to happen on any fast api - when clicking the swagger ui expander. https://developer.mongodb.com/how-to/FARM-Stack-FastAPI-React-MongoDB

Same here.

Same story from swagger-ui as last time #1762 ?

I've got the 404 error with swagger-ui-dist@3.39, so I'll just rollback to swagger-ui-dist@3.38 for now.

Same story from swagger-ui as last time #1762 ?

I've got the 404 error with swagger-ui-dist@3.39, so I'll just rollback to swagger-ui-dist@3.38 for now.

Is there a problem with swagger-ui-dist@3.38？if no problem, can you please tell me how to rollback this version, thank you.

The same thing. Besides when I run my app on localhost it works perfectly. When I run the app from docker container and try to connect to server, running on localhost, I see this error.

I am having the same error, I think this is just an stetic issue, right?, I am not having any operational issue yet, can you confirm if this could become a pain?

Created a pull request with a temporary fix to this (#2656).
Thanks @Gatux for linking the issue with the monkey patch.

@emir-mx It's only a docs issue, not a operational issue from any of your code.

Created a pull request with a temporary fix to this (#2656).
Thanks @Gatux for linking the issue with the monkey patch.

Great, It works for me! Thank you

Nice thanks @Gatux

The by @ArcLightSlavik mentioned temp fix works perfectly..

Hi, I started having the same "GET /%5Bobject%20Module%5D HTTP/1.1" 404 Not Found issue

INFO:     127.0.0.1:44526 - "GET /api/auth/%5Bobject%20Module%5D HTTP/1.1" 404 Not Found

This INFO logger message is triggered the first time I click on any of the FastAPI Swagger UI buttons in API /docs endpoint. Perhaps that will help package authors to trace the problem.

I'm also using FastAPI v0.63.0 and yes @ArcLightSlavik temp fix works fine.

@athanhat I'm facing the same issue. Any updates on that?

#metoo

#same

INFO: 127.0.0.1:52860 - "GET /%5Bobject%20Module%5D HTTP/1.1" 404 Not Found I'm also facing same issue on mac.

I am facing the same issue. In NestJs Swagger UI

I'm seeing this as well in Swashbuckle.AspNetcore version 6.0.0. I've opened domaindrivendev/Swashbuckle.AspNetCore#1993 to try to get more information on the root cause, I know it's only tangentially related but I'm linking here for the sake of anyone else googling this issue.

It also returns a 404 response when passing url as a path parameter.

from fastapi import APIRouter
from .models import OpenGraphMetaTags

router = APIRouter()

@router.get(
    path='/opengraph-metatags/{url}',
    response_model=OpenGraphMetaTags,
    response_model_by_alias=True,
    response_model_exclude_none=True,
)
async def parse_metatags(url: str):
    ...

Above code works if path paremeter is a plain string eg. some-string, but not for something like https://facebook.com. Terminal logs show that the request url is

INFO: 127.0.0.1:59924 - "GET /opengraph-metatags/https%3A//facebook.com HTTP/1.1" 404 Not Found

It fails to encode the slashes. On swagger I have the following data, tho

I hope this gets fix soon. I really love FastAPI