Specifying a port does not work, always a random port is assigned.

First Check

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Example Code

from fastapi import FastAPI

app= FastAPI(
    redoc_url= None,
)

app.get("/")
async def root():
    return ("test")

Description

I am trying to run the code above,

python -m uvicorn main:app --port=8000 --reload

Which runs the API, that part is OK. However, the port is always assigned randomly and I cannot find a way to fix this.

INFO: Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit) INFO: Started reloader process [2432] using StatReload INFO: Started server process [2524] INFO: Waiting for application startup. INFO: Application startup complete. INFO: 127.0.0.1:64692 - “GET /docs HTTP/1.1” 200 OK INFO: 127.0.0.1:64692 - “GET /openapi.json HTTP/1.1” 200 OK

Operating System

Windows

Operating System Details

Windows 11 Home SL

FastAPI Version

0.68.0

Python Version

3.10.2

Additional Context

No response

[Blue9]

As @Kludex mentioned, 127.0.0.1:64692 is the client address, and your server is still running on port 8000. If you’d like to learn more you can read about ephemeral ports.

[Kludex]

INFO: Uvicorn running on http://127.0.0.1:8000/ (Press CTRL+C to quit)

Server ☝️

INFO: 127.0.0.1:64692 - “GET /docs HTTP/1.1” 200 OK INFO: 127.0.0.1:64692 - “GET /openapi.json HTTP/1.1” 200 OK

Client ☝️