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. If you're signed in, this is also linked to your account. We do not store your code or the AI's response.
Purchases: if you buy AI credits, Stripe (our payment processor) handles your card details directly, and we never see or store them. We keep a record of what you bought and when, linked to your account.
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, and to track any paid AI credits you've bought and used.
Purchase record: so paid features actually unlock for you, and so we can handle refunds or support questions.
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, name, and AI usage log immediately. Your solve history is anonymised and kept to preserve percentile rankings for others. This is immediate and irreversible.
Purchase records are the one exception: we keep these after account deletion, no longer linked to your name or email, because we're required to retain transaction records for accounting purposes. Stripe separately retains its own copy of every payment regardless of what we do on our end.
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, and Stripe for payments if you buy AI credits. Anthropic does not use API inputs to train its models. Stripe handles your card details directly and processes the payment on our behalf: see their own privacy policy for how they handle it.
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. Signed-in users can also buy additional AI credits, described under "Purchases" above.