Using FastAPI’s CORSMiddleware with allow_credentials=True and allow_origins=["*"] looks like it should “allow all origins with credentials,” but browsers refuse credentialed CORS responses when Access-Control-Allow-Origin is *. This leads to confusing behavior where requests may hit the API but the frontend still gets blocked by the browser.
Using FastAPI’s CORSMiddleware with allow_credentials=True and allow_origins=["*"] looks like it should “allow all origins with credentials,” but browsers refuse credentialed CORS responses when Access-Control-Allow-Origin is *. This leads to confusing behavior where requests may hit the API but the frontend still gets blocked by the browser.