What does HTTP status 308 (Permanent Redirect) mean?

HTTP_STATUS_PERMANENT_REDIRECT

The target URI appears in Location. Unlike 301 and 302, 308 explicitly tells clients not to change a POST, PUT, or other request method when following the redirect.

This makes 308 appropriate when an API endpoint moved but the original operation must remain semantically identical. Verify redirect loops and cache behavior when deploying it.

The method-preservation rule makes 308 appropriate when a permanent relocation must not turn a POST into a GET. Because the redirect is permanent and can be cached, verify the destination carefully before deployment. Clients should still protect non-idempotent requests from accidental duplicate submission when a network failure obscures the redirect outcome.

RFC 7538: Permanent Redirect