The value of Content-Type is converted to binary issue with FastAPI(fastapi==0.111.1)

[pawlean (Pauline P. Narvas)]

Also cross-posting this message from another thread that may be helpful.

Vercel Functions - Content-Type header in vercel.json not working

This is because by default response returns have a Content-Type set, so that overrides your top level content type. a default function response on Vercel returns text/plain you can always just make a custom response that’s just the base response + the json header like so export class JsonResponse extends Response { constructor(body: any, init?: ResponseInit) { super(JSON.stringify(body), { ...init, headers: { ...init?.headers, "Content-Type": "application/json" }, }); } …