Terms of Service — foil.tools

Effective date: August 18, 2026 (previous version: June 16, 2026) Operator: FOIL.TOOLS LLC ("foil.tools," "we," "us," "our") Mailing address: PO Box 119, Husum, WA 98623 Contact: [email protected]

By accessing or using foil.tools (the "Service"), you agree to these Terms of Service (the "Terms"). If you do not agree, do not use the Service.

1. The Service

foil.tools is a web-based toolkit for searching, analyzing, comparing, optimizing, and designing aerodynamic airfoils and wings, including a public API and a Model Context Protocol (MCP) interface. Results are numerical estimates produced by simplified computational models.

2. Eligibility & accounts

You must be at least 16 years old (or the age of digital consent in your jurisdiction) to create an account. Accounts are provided through our authentication provider (Clerk). You are responsible for activity under your account and for keeping API keys confidential. You must provide accurate information and may not register if you are barred under Section 9 (Export Control & Sanctions).

3. Acceptable use

Your use is governed by our Acceptable Use Policy, incorporated by reference. In summary, you may not use the Service for weapons, munitions, missile, or military-UAV development; for any unlawful purpose; in violation of export-control or sanctions law; or to abuse, scrape, or circumvent the limits of the Service. We may refuse, throttle, suspend, or terminate access for any violation.

4. Payments, credits, and taxes

4.1 Certain compute features (e.g., optimization, wing analysis, extra analyses) consume credits. Credits may be purchased in packs via our payment processor (Stripe). 4.2 Credits are a limited license to use foil.tools compute. They are not money, have no cash value, are non-transferable, and are non-refundable except as required by law or stated in our Refund & Payments Policy. 4.3 Prices and credit costs are shown in the Service and in the Refund & Payments Policy. We may change pricing prospectively. 4.4 You are responsible for any applicable taxes; where required, taxes are calculated and collected at checkout. 4.5 We do not store your full payment-card details; payment processing and card data are handled by Stripe under its own terms.

5. Your content

You retain ownership of airfoil and wing designs and other content you create or upload ("User Content"). You grant us a limited, non-exclusive license to store, process, transmit, and display User Content solely to operate and provide the Service. You are responsible for your User Content and represent that you have the rights to it.

5.1 Publishing to the community

User Content is private by default. If you choose to publish it — for example by publishing a wing design to the community area — you additionally grant us a non-exclusive, worldwide, royalty-free license to display, reproduce, and distribute that content publicly, including to people who do not have an account, and to show it in previews, link cards, and search results. You continue to own it.

When you publish, you pick how open it is:

Showcase — others may view your design, its measured properties, and its analysis, but the editable geometry is not distributed.
Open — you additionally grant every user a non-exclusive, worldwide, royalty-free license to download your design, to create derivative designs from it, and to publish those derivatives on the Service, provided the Service's attribution to you as the original author is preserved.

You may unpublish a design or change it from open to showcase at any time. Doing so stops further distribution by us, but does not revoke rights already exercised: copies and derivative designs others made while it was open remain theirs to keep and use. If that is not acceptable to you, publish as showcase.

You may only publish content you have the rights to publish. Publishing someone else's design as your own is a breach of these Terms and of the Acceptable Use Policy, and we may remove it and revoke your ability to publish.

6. Our intellectual property

The Service, its software, the CST implementation, branding, and design are owned by FOIL.TOOLS LLC or its licensors and are protected by law. Airfoil datasets and aerodynamic methods incorporated in the Service derive from publicly available sources and their respective licenses. Except for the rights expressly granted, no license is conveyed.

7. Engineering-output disclaimer

The Service provides numerical estimates from simplified aerodynamic models (including CST parameterization and XFOIL/NeuralFoil-based methods). Outputs are not validated engineering results. You must independently verify any result through wind-tunnel testing or high-fidelity CFD before relying on it, and you must not use the Service as the sole basis for designing, certifying, or building safety-critical or flight hardware. You assume all risk arising from use of any output.

8. Warranty disclaimer & limitation of liability

8.1 THE SERVICE IS PROVIDED "AS IS" AND "AS AVAILABLE," WITHOUT WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, ACCURACY, AND NON-INFRINGEMENT. 8.2 TO THE MAXIMUM EXTENT PERMITTED BY LAW, FOIL.TOOLS LLC WILL NOT BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES, OR FOR LOSS OF PROFITS, DATA, OR GOODWILL. 8.3 OUR TOTAL LIABILITY FOR ANY CLAIM ARISING FROM THE SERVICE WILL NOT EXCEED THE GREATER OF (a) THE AMOUNTS YOU PAID US IN THE 12 MONTHS BEFORE THE CLAIM, OR (b) USD $100.

9. Export control & sanctions

You represent and warrant that you are not located in, ordinarily resident in, or a national of any comprehensively sanctioned jurisdiction, and that you are not on any U.S. government denied-party, blocked-person, or sanctions list. You agree not to use or export the Service in violation of U.S. export-control laws (including the EAR and ITAR) or economic-sanctions laws. We may block, refuse, or terminate access to comply with these laws. See the Acceptable Use Policy for details.

10. Indemnification

You will indemnify and hold harmless FOIL.TOOLS LLC from claims, losses, and expenses (including reasonable legal fees) arising from your use of the Service, your User Content, or your violation of these Terms or applicable law.

11. Suspension & termination

We may suspend or terminate your access at any time for violation of these Terms, suspected abuse, or to comply with law. On termination, your right to use the Service and any remaining credits cease, except as required by law.

12. Changes

We may update these Terms; material changes will be posted with a new effective date. Continued use after changes constitutes acceptance.

13. Governing law & disputes

These Terms are governed by the laws of the State of Washington, excluding its conflict-of-laws rules. The exclusive venue for disputes is the state or federal courts located in Washington, and you consent to that jurisdiction.

14. Contact

Questions: [email protected].