xint-oauth-callback-port-is-3333-not-8477
The xint OAuth PKCE callback server listens on port 3333, not the commonly assumed 8477. The X Developer Portal app’s Callback URI must be set to http://127.0.0.1:3333/callback exactly. Configuring 8477 in the portal causes a ‘redirect_uri_mismatch’ error during the OAuth flow. Correct URI to register: http://127.0.0.1:3333/callback.