Example code

authRouter.use(mcpAuthRouter({
    baseUrl: new URL('https://example.com/auth'),
    // ...
  }));

Expected behavior
OAuth endpoints should start with https://example.com/auth/ (i.e. https://example.com/auth/authorize).
However, createOAuthMetadata uses absolute paths for endpoints, which causes the /auth/ prefix to be omitted.