How to get route's name using FastAPI/Starlette?

Question

How can I get the name of a route/endpoint using FastAPI/Starlette? I have access to the Request object and I need this information in one of my middlewares. For example, if I hit services/1, I should then be able to get the abc name. Is this possible in FastAPI?

@app.get("/services/{service}", name="abc")
async def list_services() -> dict:
    do something

Update 1: Output of request.scope

{'type': 'http', 'asgi': {'version': '3.0', 'spec_version': '2.3'}, 'http_version': '1.1', 'server': ('127.0.0.1', 8001), 'client': ('127.0.0.1', 56670), 'scheme': 'http', 'root_path': '', 'headers': [(b'user-agent', b'PostmanRuntime/7.29.2'), (b'accept', b'*/*'), (b'postman-token', b'f2da2d0f-e721-44c8-b14f-e19750ea8a68'), (b'host', b'localhost:8001'), (b'accept-encoding', b'gzip, deflate, br'), (b'connection', b'keep-alive')], 'method': 'GET', 'path': '/health', 'raw_path': b'/health', 'query_string': b'', 'app': <fastapi.applications.FastAPI object at 0x1036d5790>}

Update 2:
Providing middleware code where request.scope["route"] is breaking.

from fastapi import FastAPI,Request
    
app = FastAPI()


@app.middleware("http")
async def logging_middleware(request: Request, call_next):
    print(request.scope['route'].name)
    response = await call_next(request)
    return response

@app.get('/', name='abc')
def get_name(request: Request):
    return request.scope['route'].name

Asked By: Devendra Singh khurana

||

Source

Answer 1

Option 1

You can get the name value inside an endpoint as follows:

from fastapi import FastAPI,Request
    
app = FastAPI()

@app.get('/', name='abc')
def get_name(request: Request):
    return request.scope['route'].name

Option 2

In a middleware, make sure to get the route’s name after calling call_next(request), otherwise you would be faced with KeyError: 'route', as the route key/object would not yet exist in the scope dictionary. Example:

@app.middleware("http")
async def some_middleware(request: Request, call_next):
    response = await call_next(request)
    print(request.scope['route'].name)
    return response

Option 3

Instead of a middleware, you could create a custom APIRoute class, which would allow you to get the route’s name before processing the request and getting the response (if that’s a requirement for your app). You could add an endpoint that you would like to be handled by that APIRoute class using @<name_of_router_instance> instead of @app (e.g., @router.get('/', name='abc')). More than one endpoint could be added in the same way. Example:

from fastapi import APIRouter, FastAPI, Request, Response
from typing import Callable
from fastapi.routing import APIRoute

class CheckNameRoute(APIRoute):
    def get_route_handler(self) -> Callable:
        original_route_handler = super().get_route_handler()

        async def custom_route_handler(request: Request) -> Response:
            print(request.scope['route'].name)
            response = await original_route_handler(request)
            return response

        return custom_route_handler


app = FastAPI()
router = APIRouter(route_class=CheckNameRoute)
    
@router.get('/', name='abc')
def get_name(request: Request):
    return request.scope['route'].name
 
app.include_router(router)

Answered By: Chris

How to get route's name using FastAPI/Starlette?

Question:

Answers:

Option 1

Option 2

Option 3