xint-oauth-callback-port-3333-not-8477
xint’s local OAuth callback server listens on port 3333, not the commonly assumed 8477. The X Developer Portal app’s callback URL must be set to http://127.0.0.1:3333/callback exactly. Configuring it with the wrong port (e.g., 8477) produces an X OAuth redirect_uri_mismatch error after the user authorizes, blocking the code exchange.