Users report that Hugging Face Spaces' edge proxy is now stripping the Access-Control-Allow-Credentials header from OPTIONS preflight requests, even when explicitly configured in Express middleware. The header is missing in responses despite code that sets it and includes a wildcard middleware for OPTIONS requests, suggesting the proxy intercepts and modifies the response before it reaches the backend container.
Hugging Face Spaces Proxy Strips CORS Credentials Header on OPTIONS Preflight
from English