Privacy Policy

Last updated: June 8, 2026

What We Collect

  • Account info: name, email, and profile image (provided via Google OAuth when you sign in)
  • Usage data: pages visited, content viewed, time on site, module progress, XP earned, and checkpoint completions
  • AI conversations: questions you ask the assistant (used to generate a response; see retention below)
  • Cookies: authentication tokens (essential) and analytics (optional, opt-in via the consent banner)

How We Use Your Data

  • To provide and personalize the learning experience
  • To track your progress, streaks, and achievements
  • To process payments via Stripe (we never see your card details)
  • To send transactional emails via Resend (purchase confirmations only)
  • To display public profiles and leaderboards (opt-in)

Third-Party Services

  • Supabase — database and authentication (your data is stored in Supabase-managed Postgres)
  • Anthropic — Claude API for the AI assistant and content pipeline
  • Google — Gemini API for embeddings, and OAuth for sign-in
  • Vercel — hosting, analytics, and speed insights
  • Resend — transactional email delivery
  • Sentry — error monitoring and crash reporting
  • Upstash — rate limiting (when enabled)
  • Stripe — payment processing (PCI-compliant, we never store card data)

Cookies

  • Essential: authentication session cookies (Supabase). Without these, you cannot sign in.
  • Optional: Vercel Analytics and Vercel Speed Insights. Controlled via the cookie consent banner.
  • Referral: zts_ref stores a referral code temporarily and is cleared after sign-up.

Data Retention

  • Account data: retained until you delete your account
  • Analytics: anonymized after 24 months
  • AI conversation logs: not retained — your queries are processed in real time but not stored as conversation history
  • Server logs: 30 days

Your Rights

  • Access your data — request a copy by emailing us
  • Delete your account and all associated data — use the in-app deletion flow which calls POST /api/account/delete, or email us
  • Opt out of analytics cookies — decline via the cookie consent banner shown on your first visit
  • Correct your personal data — email us and we'll respond within 30 days

Contact

Questions about this policy, or want to exercise your data rights? Email us at ethan.c.stuart@gmail.com.