Privacy Policy
Last updated: 22 February 2026
1. Who we are
MathCraft is an educational maths app for children aged 7–12. We are based in Barcelona, Spain. If you have any questions about how we handle your data, contact us at hello@math-craft.app.
2. What data we collect
| Data | Who | How |
|---|
| Email address | Parent | Account signup (optional) |
| Password | Parent | Hashed by Supabase Auth — we never see or store your plain password |
| 4-digit PIN | Parent | Stored locally on device only — never sent to our servers |
| First name | Child | Entered during setup — used to personalise the experience |
| Age / year level | Child | Used to select appropriate curriculum content |
| Gameplay data | Child | Answers, accuracy, time spent, companion choices, island progress |
| AI tutor conversations | Child | Conversations with Merlin (AI wizard) — visible to parent in dashboard |
| Analytics events | Both | Session events, question accuracy, feature usage — batched and anonymised |
3. How we use your data
- Personalise learning: Adapt question difficulty, select curriculum topics, track mastery progression
- Show progress: Display accuracy, streaks, and curriculum coverage in the parent dashboard
- Improve the app: Understand which features work, identify bugs, improve question quality
- Communicate: Send setup instructions or respond to support requests (parent email only)
We do not use your data for advertising, marketing profiling, or any purpose unrelated to the educational service.
4. Where data is stored
- On the device: All gameplay data is stored in your browser’s localStorage. This is the primary data store. If you clear browser data, this data is lost.
- In the cloud (optional): If you create an account, data is synced to Supabase, hosted in the EU (Frankfurt, Germany). This enables multi-device access and backup.
5. AI tutor (Merlin)
MathCraft includes an AI tutor called Merlin, powered by Anthropic’s Claude. When your child uses the wizard:
- Conversations are processed by Claude’s API to generate Socratic maths guidance
- Anthropic does not train their models on your child’s conversations
- Every conversation is logged and visible to you in the parent dashboard
- Merlin is restricted to maths topics only and limited to 5 uses per day
- No personal data beyond the conversation content is sent to Claude
6. Children’s data & ICO Children’s Code
We take children’s data protection seriously. MathCraft is designed to comply with the ICO Age Appropriate Design Code (Children’s Code) and UK GDPR:
- Parental consent: A parent must set up the app before a child can use it
- No behavioural advertising: We do not show ads or profile children for marketing
- No social features: Children cannot communicate with other users
- No dark patterns: Hard time limits, no loot boxes, no infinite scroll, no push notification manipulation
- Minimal data collection: We only collect what is necessary for the educational service
- Transparency: Parents can see all data through the dashboard, including AI conversations
7. Data sharing
We do not sell, rent, or share your personal data with third parties. The only services that process data on our behalf are:
- Supabase (database hosting, EU) — stores account and sync data
- Anthropic (AI API) — processes wizard tutor conversations only
- Sentry (error tracking) — receives anonymised error reports only
8. Data retention
- Account data is kept until you request deletion
- Device-only data (localStorage) is under your control — clear it anytime
- Analytics events are retained for 12 months, then automatically deleted
9. Your rights
Under UK GDPR, you have the right to:
- Access your data — request a copy of all data we hold
- Correct inaccurate data
- Delete your data — request complete account deletion
- Export your data — the parent dashboard includes a data export feature
- Withdraw consent at any time
To exercise any of these rights, email hello@math-craft.app. We will respond within 30 days.
10. Cookies
MathCraft uses minimal cookies:
- Supabase auth token: Required for cloud sync functionality (functional cookie)
- We do not use tracking cookies, advertising cookies, or third-party analytics cookies
11. Contact
Terms of Service
Last updated: 22 February 2026
1. The service
MathCraft is an educational web application (PWA) that provides gamified maths practice for children aged 7–12, aligned to the White Rose Maths curriculum. The service is currently in free beta.
2. Accounts
- Parents are responsible for setting up and supervising their child’s use of MathCraft
- Account creation requires a valid email address and is optional during beta
- You are responsible for keeping your account credentials and PIN secure
3. Acceptable use
MathCraft is designed for children to use under parental supervision. Users must not:
- Attempt to extract, reverse-engineer, or misuse the AI tutor
- Use the service for any purpose other than educational maths practice
- Interfere with the service or other users’ experience
4. Data & privacy
Your use of MathCraft is subject to our Privacy Policy above.
5. Availability
MathCraft is provided “as is” during the beta period. We aim for high availability but cannot guarantee uninterrupted service. Data stored in localStorage is your responsibility — we recommend enabling cloud backup for important progress.
6. Intellectual property
All content, code, artwork, and game design in MathCraft is owned by MathCraft. The pixel art assets are used under licence from their respective creators.
7. Beta terms
During the beta period:
- The service is free of charge
- Features may change without notice
- We welcome and encourage feedback
- We may transition to a paid service after beta, with advance notice
8. Contact
Questions about these terms? Email hello@math-craft.app.