Privacy Policy

Last Updated: December 28th, 2025

This Privacy Policy explains how we collect, use, store, and share your personal information when you use mtgbuilder.ai. Our service is an intelligent card search assistant designed to help you find Magic: The Gathering cards using natural language queries.

Your privacy is important to us. Please read this policy carefully to understand what data we collect, why we collect it, and how we handle your information.

1. Information We Collect

We collect the following types of information to provide and improve our services:

a. Google Account Information

  • What is collected: Your name, email address, and profile picture (as provided by Google when you sign in).
  • Why we collect it: To create and identify your user account within our system (Supabase) and to personalize your experience.

b. Usage and Conversation Data

  • What is collected: Your natural language queries, chat history, and interactions with the card search results (e.g., thumbs up/down feedback).
  • Why we collect it:
    • To provide the core service: processing your queries to return relevant card results.
    • To maintain your conversation history so you can review past searches.
    • Note on Beta: During this beta phase, conversation logs are sent to PostHog and are not anonymized. We use this data to debug AI workflows, fix hallucinations, and improve the quality of search results.

c. Payment and Credit Information

  • What is collected: We store your current credit balance and a record of credit consumption. Actual payment processing is handled by Stripe. We do not store your credit card numbers or financial details on our servers; we only store transaction metadata (e.g., purchase success, amount of credits bought).
  • Why we collect it: To manage your credit pool and ensure you can use the paid features of the service.

d. Technical Data

  • What is collected: IP addresses, browser type, and device information.
  • Why we collect it: For security, fraud prevention, and to analyze how our application is accessed (via Vercel and PostHog).

2. How We Use Your Information

We use your information for the following purposes:

  • To provide the service: Authenticating you, processing your card searches, and managing your credit balance.
  • To improve our AI: Analyzing real-world queries to train our agents and improve the accuracy of the semantic search.
  • To communicate with you: Sending important updates about your account or changes to our policies.

3. How We Share and Disclose Information

We do not sell your personal information to anyone.

Third-Party Service Providers (Sub-processors)

We work with trusted third-party services to provide and improve our app.

  • Google
  • Supabase
    • Role: Hosts our database, storing your user account, conversation history, and usage data.
    • Policy: Supabase Privacy Policy
  • Stripe
  • PostHog
    • Role: Collects analytics and conversation logs for debugging and product improvement.
    • Policy: PostHog Privacy Policy
  • Vercel
    • Role: Hosts our web application; uses your IP address to infer location (not stored by us).
    • Policy: Vercel Privacy Policy
  • Google Gemini (LLM Provider)

4. Data Security

We are committed to protecting your personal information:

  • Your data is stored securely in our database (Supabase).
  • We do not handle sensitive financial data directly; it is processed by Stripe.
  • Access to debug logs is restricted to the engineering team for development purposes only.

5. Data Retention and Deletion

  • How long we keep your data: We keep your information as long as your account is active.
  • How to delete your data:
    • If you wish to delete your account and all related data, please email us at lau.cazanove@gmail.com.
    • Deletion includes:
      • Your user account in Supabase.
      • Your conversation history and stored credits.

6. Your Rights

Depending on your location, you may have the right to access, correct, or request deletion of your data. To exercise these rights, please contact us at lau.cazanove@gmail.com.

7. Contact Us

If you have any questions about this Privacy Policy, please contact us at:

8. Changes to This Policy

We may update this Privacy Policy from time to time. We will notify you of significant changes by posting an update on mtgbuilder.ai.