Duke Privacy Policy
Last updated October 2026
Duke runs on your own Mac and plays your own Duolingo account. It has no accounts, no ads, no analytics and no tracking cookies. Nothing is sold.
What stays on your Mac
Your Duolingo session cookie, the browser profile, and the logs of every lesson (state.json, log.jsonl, lessons.jsonl). The cookie is only ever sent to Duolingo.
What Duke shares, and with whom
- Duolingo sees what it always sees when you play: your answers, your XP, your streak.
- The status apps read the runner's live state over your network: course, XP, streak, the current question and answer, and your Duolingo username.
- The public tunnel. If you run the Cloudflare tunnel, that same live state is readable by anyone at your status address, and the landing page shows it as a live demo. Pausing, switching course and the screenshot need a token. Turn the tunnel off to keep it all on your network.
The website
duke.jaybulb.com (surf.jaybulb.com still serves) is a static page on Cloudflare Pages. It sets no cookies and runs no analytics. Cloudflare keeps standard request logs, as every host does.
Kids
Duke isn't made for children under 13 and doesn't knowingly collect anything from them.
