Azure APIM warning: Backend service responded with a redirect. Response shown by-passed API Management proxy and came directly from the endpoint specified in the redirect response

Question

Azure APIM throws below warning in developer portal even though it returns 200 response code and expected data properly from the backend Azure function.
Azure function has Azure AD authentication enabled and the API uses OAuth authentication server configured in the APIM.

Backend service responded with a redirect. Response shown by-passed API Management proxy and came directly from the endpoint specified in the redirect response

What could be the reason?

Answer 1

@skdev the default behavior of the forward-request policy is to not follow redirects which causes clients to perform the redirect instead.

In this case, while the original request is to your APIM instance, the final response is what the backend returned after your browser followed the redirect. Hence the warning.

If having clients follow the redirect is the expected behavior, you don't really have to change anything but if otherwise, you could set the follow-redirects attribute to true in your forward-request policy.