Privacy
Last updated 25 June 2026 · Crux v0.2 preview
Crux is a math coaching prototype. This page is plain English. It will be updated as the product becomes commercial.
What we collect
- An anonymous identifier (a UUID) stored in a cookie on your browser and in our database. It does NOT contain your name, email, or any personal information unless you choose to add one in a future version.
- Your in-app activity: which curriculum you chose, your self-rating, the topics you attempted, your answers, latencies, hints used, and which questions you got right or wrong. This is necessary for the adaptive engine to work.
- No tracking pixels. No third-party analytics in this preview. No advertising. No social-network buttons.
Where it lives
- Your browser (cookie + localStorage).
- Our Cloudflare D1 database (encrypted at rest, hosted by Cloudflare).
- Nothing is sold, shared with advertisers, or sent to third-party analytics services in this preview.
What you can do
- Export your progress as a JSON file from the dashboard — that file IS your account, and it's yours.
- Reset deletes the local copy and pushes an empty state to our database. Use it from the top-right nav.
- Erasure request — email sushmita@yuriskin.com with your anonymous ID (you can find it in your browser cookies under
crux_uid) and we will delete the corresponding row from the database within 30 days.
Children
Crux is designed for students. We do not knowingly collect any personally-identifying information about anyone, including minors. If you are under 13, please use this product with a parent or guardian's awareness.
Contact
Questions, deletion requests, suggestions: sushmita@yuriskin.com.