Terms of Service – ChessOnyx

Last updated: February 2026

Convenience Translation: This English version is provided for information purposes only. The legally binding version is the German "Nutzungsbedingungen".

1. Scope

These Terms of Service apply to the entire use of the ChessOnyx platform, operated by Engin Murat, Otto-Röhm-Str. 38, 64293 Darmstadt. By registering an account or using the analysis tools, you agree to these terms.

2. Platform Services

ChessOnyx provides software tools for analyzing chess games (e.g., via PGN upload). No Guarantee of Success: Analyses are generated automatically by engines. We assume no liability for absolute accuracy, skill level assessments, or the absence of errors in analyses. Availability: We strive for high availability of the platform. However, there is no claim to 100% server availability (especially computing power for engine analyses).

3. Registration and Paid Subscriptions

Account: An account is required for certain functions. You are obliged to keep your access data secret. Payments and Billing (Merchant of Record): Our order process is conducted by our online reseller Paddle.com. Paddle.com is the Merchant of Record for all our orders. They provide all customer service inquiries and handle returns. When you purchase a subscription for ChessOnyx, the contract is formed between you and Paddle.com. Your payment details will be processed securely by Paddle, and you will see "PADDLE.NET* CHESSONYX" on your billing statement. Subscription Terms: By subscribing to ChessOnyx Pro, you agree to the recurring billing cycle (monthly or annual) as selected during checkout. You can manage or cancel your subscription at any time through your user dashboard or by contacting Paddle support. Cancellation Button: In accordance with legal requirements for 2026, you will find an easily accessible button in your user profile to cancel subscriptions at any time at the end of the term or to revoke contracts.

4. Right of Withdrawal

You have the right to withdraw from this contract within fourteen days without giving any reason. The withdrawal period is fourteen days from the day of the conclusion of the contract. To exercise your right of withdrawal, you must inform us (Engin Murat, info@chessonyx.com) of your decision by means of a clear statement (e.g., email or via the withdrawal button on the website).

5. Fair Play & Anti-Cheating

Prohibition of Live Assistance: Using ChessOnyx analysis tools for assistance during an ongoing chess game (whether online on other platforms or at official tournaments) is strictly prohibited. Misuse: Automated querying of analyses by bots or scripts ("scraping") is prohibited unless written permission has been granted. Blocking: In case of reasonable suspicion of Fair Play violations or misuse of our infrastructure, we reserve the right to temporarily or permanently block user accounts.

6. Limitation of Liability

We are only liable for damages in cases of intent or gross negligence. For slight negligence, we are only liable for the breach of essential contractual obligations (cardinal obligations). ChessOnyx is not liable for any sporting or financial losses (e.g., in tournaments or betting) resulting from the use or incorrect display of analyses.

7. Data Protection and Infrastructure

Data Processing: We process your data (login, PGN files) only to provide our services. Service Providers: We use Vercel (frontend/hosting) and Supabase (database) to provide the platform. Your data is stored there within the framework of technical necessity. We keep your data only as long as your account exists or as provided by the retention periods of our service providers. Please refer to our Privacy Policy for details.

8. Updates and Changes

We reserve the right to further develop the platform technically. We will inform you in good time about necessary updates or changes to the terms of use by email or via the platform.

9. Final Provisions

The law of the Federal Republic of Germany applies. Should individual provisions of these conditions be ineffective, the validity of the remaining provisions remains unaffected (severability clause).