middleware.py

import time

from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware

app = FastAPI()


# The middleware function receives:
#
# The request.
# A function call_next that will receive the request as a parameter.
# This function will pass the request to the corresponding path operation.
# Then it returns the response generated by the corresponding path operation.
# You can then modify further the response before returning it.
@app.middleware("http")
async def add_process_time_header(request: Request, call_next):
    start_time = time.time()
    response = await call_next(request)
    process_time = time.time() - start_time
    response.headers["X-Process-Time"] = str(process_time)
    return response

origins = [
    "http://localhost.tiangolo.com",
    "https://localhost.tiangolo.com",
    "http://localhost",
    "http://localhost:8080",
]

app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


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

# can use ['*'] to allow any origin