Mustmark

Privacy Policy

Last updated: October 25, 2026

This Privacy Policy explains how Mustmark ("we", "us", or "our") collects, uses, and protects information when you use our website, application, and services (collectively, the "Service"). By using the Service, you agree to the practices described in this policy.

1. Information We Collect

We collect the following categories of information:

  • Account information: your email address, which you provide when you sign in.
  • Content you submit: the URLs, articles, notes, and other text you upload or paste into the Service, as well as the memory cards, summaries, and evaluations generated from that content.
  • Usage data: information about how you interact with the Service, such as the number of evaluations performed and pages visited.
  • Browser extension data: if you install our browser extension, the URL and content of the web pages you choose to send to Mustmark.

2. How We Use Your Information

We use your information to:

  • Provide, maintain, and improve the Service;
  • Process and evaluate the content you submit using automated evaluation models;
  • Send you service-related emails (for example, daily review-reminder emails if you are subscribed);
  • Authenticate your account and enforce usage limits;
  • Detect, prevent, and address fraud, abuse, and technical issues.

3. Lawful Basis for Processing

Under the EU General Data Protection Regulation (GDPR), we rely on the following lawful bases to process your personal data:

  • Contract (Art. 6(1)(b)): processing necessary to provide the Service you requested, including account authentication, content evaluation, and subscription billing.
  • Legitimate interest (Art. 6(1)(f)): processing for security, fraud prevention, abuse detection, and improving the reliability of the Service.
  • Consent (Art. 6(1)(a)): where we send you optional review-reminder emails. You can withdraw consent at any time by unsubscribing or contacting us.
  • Legal obligation (Art. 6(1)(c)): where processing is required to comply with applicable law, such as tax or accounting records.

4. Automated Decision-Making

The Service uses automated evaluation models to assess the “memory worthiness” of content you submit and to generate summaries, memory cards, and review schedules. This automated processing does not produce legal or similarly significant effects on you. You may request human review of any automated evaluation by contacting us at the address below.

5. Cookies

We use cookies to operate the Service. The cookies we use are:

  • kr_user_id — a signed session cookie that keeps you signed in.
  • kr_guest_uses — a signed cookie that tracks the number of free evaluations used by signed-out visitors.
  • mustmark_lang — your preferred display language, stored in your browser's local storage.

The cookies above are strictly necessary for the Service to function and do not track you across third-party websites. You can block cookies in your browser, but doing so may prevent you from using the Service. The language preference is stored locally in your browser and never sent to our servers.

6. Third-Party Service Providers

We share your information with the following service providers, each of which processes data on our behalf under contractual obligations:

  • Content evaluation providers (such as Zhipu / BigModel): to evaluate and summarize the content you submit. Content sent to these providers is used solely to generate your results.
  • Supabase: to host your account data and content.
  • Creem: to process payments for paid subscriptions. Creem acts as the merchant of record and handles billing, taxes, and payment data. We do not store your full payment card details.
  • Email delivery providers: to send you service emails.

7. Data Retention

We retain your account information and content for as long as your account is active. If you delete your account or request deletion of your data, we will delete your content within a reasonable period, except where retention is required by law.

8. Your Rights

Depending on your jurisdiction (including the EU GDPR), you may have the following rights regarding your personal data:

  • Access: request a copy of the personal data we hold about you.
  • Rectification: correct inaccurate or incomplete data.
  • Erasure: request deletion of your data. You can delete your account at any time from your account settings.
  • Portability: request your data in a structured, machine-readable format. Use the “Export my data” button in your account settings.
  • Restriction / Objection: request that we restrict or object to certain processing.
  • Withdraw consent: withdraw any consent you previously provided, without affecting the lawfulness of prior processing.

To exercise these rights, contact us at the email address below. We will respond within 30 days. You also have the right to lodge a complaint with your national data protection supervisory authority.

9. International Data Transfers

Your information may be processed in countries other than your own, including where our service providers operate. We take steps to ensure that transfers are protected by appropriate safeguards such as standard contractual clauses.

10. Security

We use reasonable technical and organizational measures to protect your information, including encrypted storage and signed session cookies. However, no method of transmission over the internet is completely secure.

11. Children's Privacy

The Service is not intended for children. In the European Union, you must be at least 16 years old to use the Service (or the minimum age set by your country, which may be as low as 13). Outside the EU, you must be at least 13. We do not knowingly collect personal information from children.

12. Changes to This Policy

We may update this Privacy Policy from time to time. We will post the updated policy on this page and update the "Last updated" date. Material changes will be communicated through the Service or by email.

13. Contact Us

If you have any questions about this Privacy Policy, our data practices, or wish to exercise your data subject rights, contact us at support@mustmark.com.

EU Representative: For users in the European Economic Area, our representative for data protection matters can be reached at support@mustmark.com.