Privacy Policy

1. Introduction

ChessSolve ("we", "us", or "our") is committed to protecting your personal data. This Privacy Policy explains what information we collect, how we use it, and your rights in relation to it.

By using ChessSolve, you agree to the collection and use of information in accordance with this policy.

2. Data We Collect

We collect the following categories of data:

• Account data — email address, username, and hashed password when you register.
• Usage data — daily and total request counts, last activity date, and your subscription status (free or premium).
• Game records — chess game data you submit for analysis or that is saved as part of the replay/history feature.
• Email preferences — whether you have consented to marketing emails and your current subscription status.
• Technical data — IP address (used for rate limiting only, not stored long-term), browser type, and standard server logs.

3. How We Use Your Data

• To provide, maintain, and improve the Service.
• To enforce fair-use limits and prevent abuse of the platform.
• To manage your account, including authentication and password security.
• To process premium subscription status and related features.
• To send service-related and marketing communications where you have consented (see Section 4).
• To comply with legal obligations.

We process your data on the basis of contract performance (to provide the Service you signed up for), legitimate interests (security, abuse prevention), and consent (marketing emails).

4. Email Communications

We may send two types of emails:

• Service & security emails — Necessary messages about your account (e.g., security notices, important changes to the Service). These are sent regardless of marketing preferences.
• Marketing emails — Occasional promotional messages, product updates, and news about ChessSolve. These are sent only if you have opted in at registration or subsequently provided consent.

How to unsubscribe: Every marketing email contains a one-click Unsubscribe link at the bottom. Clicking it immediately removes you from the marketing list. You can also contact us directly to opt out.

We use Resend as our email delivery provider. Your email address is shared with Resend solely for the purpose of delivering emails on our behalf.

5. Data Sharing & Third-Party Services

We do not sell your personal data. We share data only with the following service providers to operate the platform:

• MongoDB Atlas — database hosting for user accounts and game data.
• Resend — email delivery service for transactional and marketing emails.
• Upstash Redis — rate-limiting and caching layer (IP-level data, not linked to user identity long-term).

Each provider is bound by their own privacy policies and data processing agreements.

6. Data Retention

We retain your account data for as long as your account is active or as needed to provide the Service. If you request deletion of your account, we will delete your personal data within a reasonable period, except where retention is required by law. Game records associated with your account are deleted when your account is deleted.

7. Your Rights

Depending on your jurisdiction (including under the GDPR for EU residents), you may have the following rights:

• Access — request a copy of the personal data we hold about you.
• Rectification — request correction of inaccurate data.
• Erasure — request deletion of your personal data ("right to be forgotten").
• Withdrawal of consent — withdraw marketing email consent at any time via the unsubscribe link in any email, or by contacting us.
• Restriction & objection — request restriction of processing or object to certain uses.

To exercise any of these rights, please contact us via the Contact Us page.

8. Cookies & Local Storage

We use a minimal set of cookies required for the Service to function:

• Session cookie — used to keep you authenticated (NextAuth session token). This is a strictly necessary cookie.

We do not use advertising, analytics tracking, or third-party cookies. The browser extension may use local storage to temporarily cache analysis data on your device; this data is not transmitted to our servers except as part of normal API requests.

9. Changes to This Policy

We may update this Privacy Policy from time to time. When we do, we will update the "Effective date" at the top of this page. Material changes will be communicated via email (if you are subscribed) or a notice on the website.

10. Contact

If you have any questions about this Privacy Policy or wish to exercise your rights, please contact us via the Contact Us page.