Privacy & AI
What we collect
Full account: email and optional first name, linked to a persistent login. Quick-access email: name and email, stored for the session only.
Solve history: time taken, hints used, attempts, and lines of code. Linked to your account if logged in, anonymous otherwise.
AI feature: we log your email, the problem you were on, and the type of call. We do not store your code or the AI's response.
Why we collect it
Email and name: to manage your account and personalise your experience.
Solve history: to show you your personal stats and calculate anonymous percentile rankings shown to all users after a solve.
AI usage log: to enforce the limit of three free AI calls per person per day.
Who can see it
Only you can see your solve history. Aggregate solve data contributes to percentile rankings shown to all users, without your name or email attached.
We do not sell data, share it with third parties, or use it for advertising.
Retention
Your data is kept until you delete your account. Deleting removes your email and name immediately. Your solve history is anonymised and kept to preserve percentile rankings for others. This is immediate and irreversible.
Your rights
You can delete your account at any time from the Account page. For data export, corrections, or questions, email privacy@mxlabs.io.
No tracking
No analytics scripts, third-party cookies, or advertising. External services: Supabase for database and auth, Anthropic for the AI feature. Anthropic does not use API inputs to train its models.
AI feature
When you use AI review, your code and the problem's correct answer are sent to Anthropic via their API. Anthropic's privacy policy applies.
Three free calls per day. Provide your email so we can track usage. Use a name and email for session access, or create a full account to save your solve history and see your stats.