Privacy & AI
What we collect
If you create an account: your email address and optional first name.
When you solve a problem: time taken, hints used, number of attempts, and lines of code. This data is linked to your account if you're logged in, or stored anonymously otherwise.
When you use the AI feature: we log your email, the problem you were on, and the type of call (error review or code review). We do not store the content of 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 to calculate anonymous percentile rankings shown to all users after a solve.
AI usage log: to enforce the rate limit of three free AI calls per person per day.
Who can see it
Only you can see your solve history. Aggregate solve data (time, hints, attempts) 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. When you delete your account, your email and name are removed immediately. Your solve history is anonymised (the link to your account is severed) and kept to preserve percentile rankings for other users. This process is immediate and irreversible.
Your rights
You can delete your account at any time from the Account page. For other requests - data export, corrections, or questions - email privacy@mxlabs.io.
No tracking
No analytics scripts, no third-party cookies, no advertising. The only external service is Supabase (database and authentication) and Anthropic (AI feature). Supabase's privacy policy applies to authentication data. Anthropic does not use API inputs to train its models.
AI feature
When you use the AI code review feature, your code and the problem's correct answer are sent to Anthropic (Claude) via their API to generate a response. Anthropic's privacy policy applies to that data.
AI review is available as three free calls per day. You need to provide your email to use it so we can track usage.