Remote MCP OAuth triggers sign-in via 401 response

Remote Model Context Protocol (MCP) servers with OAuth must return a specific 401 Unauthorized response pointing to resource metadata in order to trigger sign-in windows in clients like Claude or ChatGPT. However, because health checkers and directories often treat these same 401s as outages, developers must inspect incoming User-Agent headers or request payloads to differentiate between anonymous discovery requests and authenticated OAuth clients. Open article →