TERMS OF SERVICE

Last updated July 13, 2026

AGREEMENT TO OUR LEGAL TERMS

These Terms of Service ("Terms") constitute a legally binding agreement made between you, whether personally or on behalf of an entity ("you"), and Plinth LLC ("Company," "we," "us," or "our"), concerning your access to and use of the Plinth website at https://www.plinthdesign.org and the related products, features, and services we provide (collectively, the "Services"). Plinth LLC is a limited liability company organized under the laws of the State of Colorado, located at 472 Red Thistle Drive, Highlands Ranch, CO 80126, United States.

By accessing or using the Services, you agree that you have read, understood, and agree to be bound by all of these Terms. If you do not agree with all of these Terms, then you are expressly prohibited from using the Services and you must discontinue use immediately.

Supplemental terms or documents that may be posted on the Services from time to time are hereby expressly incorporated by reference. We reserve the right, in our sole discretion, to make changes or modifications to these Terms at any time and for any reason. See "CHANGES TO THESE TERMS" below.

The Services are intended for users who are at least 18 years of age. Persons under the age of 18 are not permitted to register for or use the Services.

1. OUR SERVICES

Plinth is an AI-native engineering learning platform that helps students and hobbyists build real hardware projects from scratch. When you describe an idea, Plinth produces a sourced bill of materials with live pricing, a week-by-week schedule with chained tutorials, an interactive wiring diagram, and CAD and PCB starters ready to fabricate, along with additional tools such as firmware starters, patent-readiness preparation, a market report, and a shareable project page. An AI project assistant is available throughout the workspace.

We may change, suspend, or discontinue any part of the Services at any time, including the availability of any feature, without notice or liability. The information provided when using the Services is not intended for distribution to or use by any person or entity in any jurisdiction or country where such distribution or use would be contrary to law or regulation. Those who choose to access the Services from other locations do so on their own initiative and are solely responsible for compliance with local laws.

2. ELIGIBILITY AND ACCOUNTS

You must be at least 18 years old to use the Services. By using the Services, you represent and warrant that you are at least 18 and that you have the legal capacity to enter into these Terms.

You may be required to register for an account to use certain features. You agree to keep your account credentials and access to your email secure, and you are responsible for all activity that occurs under your account. One account is permitted per person. You agree to provide accurate, current, and complete information and to keep it up to date. We may suspend or terminate your account and refuse any current or future use of the Services if any information you provide is inaccurate, or as otherwise described in these Terms.

3. SUBSCRIPTIONS, FREE TRIAL, AND AUTO-RENEWAL

Certain features of the Services require a paid subscription. Paid plans begin with a 14-day free trial, and a valid payment method is required to start the trial. Payments are processed by our third-party payment processor, Stripe; by providing a payment method you also agree to Stripe's applicable terms.

Auto-renewal. Unless you cancel before the trial ends, your payment method will automatically be charged the then-current price for the plan you selected, and your subscription will renew automatically at the end of each billing period until you cancel. Current pricing is:

Pro — $20 per month, or $192 per year billed annually.
Max — $50 per month, or $480 per year billed annually.

Prices, the billing period, and the renewal terms are shown clearly at checkout before you confirm. We send a reminder email approximately 3 days before your free trial ends and before any subscription renewal. We may change our prices from time to time; any price change will apply to billing periods that begin after the change, and we will provide notice as required by law.

Managing your subscription. You can cancel at any time from your account through the Stripe customer portal. Cancellation takes effect at the end of your current billing period, and you will retain access to paid features until then. You are responsible for all applicable taxes associated with your purchases.

4. CANCELLATION AND REFUNDS

Except where required by law, all charges are non-refundable and Plinth does not offer refunds or credits for partial billing periods. You can cancel your subscription at any time and you will not be charged again; cancellation takes effect at the end of your current billing period, and you retain access until then.

If you believe you were charged in error, contact us at support@plinthdesign.org within 30 days of the charge and we will review your request.

5. ACCEPTABLE USE

You may use the Services only for lawful purposes and in accordance with these Terms. You agree that you will not:

Scrape, data-mine, reverse engineer, decompile, or otherwise attempt to derive the source code or underlying structure of the Services;
Attempt to extract, access, or use API keys, credentials, model prompts, or other users' data;
Circumvent, disable, or interfere with security-related features or usage limits, or place undue load on our infrastructure;
Resell, sublicense, or otherwise commercially exploit access to the Services except as expressly permitted;
Use the Services or any content generated through them for any illegal, harmful, infringing, or fraudulent purpose;
Upload or transmit any material that is unlawful, infringing, defamatory, or that contains malware; or
Impersonate any person or misrepresent your affiliation with any person or entity.

We may rate-limit, suspend, or terminate accounts engaged in abuse, fraud, chargebacks, or any violation of these Terms, in our sole discretion and without liability.

6. YOUR CONTENT AND PUBLIC PROJECT PAGES

"Your Content" means the project descriptions, inputs, files, and other materials you submit to the Services, together with the outputs generated for you. As between you and us, you own Your Content, subject to the intellectual property rights of others and the terms of any third-party AI provider.

Public project pages are opt-in: you choose when, and whether, to publish a project. By making a project page public, you grant Plinth a worldwide, non-exclusive, royalty-free license to host, store, reproduce, and display that page and its contents for the purpose of operating, providing, and promoting the Services. This license ends when you unpublish or delete the project page, except to the extent the content has been shared by others or retained in backups, and except for de-identified or aggregated data.

You are solely responsible for Your Content and represent that you have all rights necessary to submit it and to grant the license above, and that Your Content does not infringe or violate the rights of any third party.

7. INTELLECTUAL PROPERTY RIGHTS

The Services, including their "look and feel" (text, graphics, logos, and design), software, and the compilation of all content on the Services (other than Your Content), are owned by or licensed to Plinth LLC and are protected by copyright, trademark, and other laws. Except as expressly permitted, you may not copy, modify, distribute, sell, or lease any part of the Services.

Subject to your compliance with these Terms, we grant you a limited, non-exclusive, non-transferable, revocable license to access and use the Services for your personal or internal business purposes. The "Plinth" name and logo are trademarks of Plinth LLC and may not be used without our prior written permission.

8. AI-GENERATED CONTENT

Plinth's bills of materials, schedules, wiring diagrams, CAD, PCB, and firmware starters, patent and market materials, and other outputs are generated by artificial-intelligence agents provided through third-party AI service providers, including OpenAI and Anthropic. AI outputs may be inaccurate, incomplete, or out of date, are not human-verified, and are not professional engineering, legal, or financial advice.

You are responsible for reviewing and verifying any output before purchasing parts, following a schedule, fabricating hardware, or making any safety-critical or legally significant decision. Your use of AI features is also subject to the applicable terms and policies of the relevant AI service provider, and you must not use the AI features in any way that violates those terms.

9. NO PROFESSIONAL ADVICE

The Services are educational tools. Bills of materials, schedules, diagrams, CAD/PCB/firmware starters, patent-readiness materials, market reports, and all other generated plans are starting points only and do not constitute professional engineering, legal, financial, or other licensed advice. You are solely responsible for verifying the safety, correctness, compliance, and suitability of any design or plan before building on or relying on it. Where appropriate, you should consult a qualified professional.

10. PATENT DISCLOSURE

Making a project public is a public disclosure for patent purposes. In the United States, you generally have one year from the date of public disclosure to file a patent application; in most other countries, public disclosure may permanently bar patent protection. Plinth's patent-readiness tools are educational preparation only and are not legal advice and do not create an attorney-client relationship. Consult a registered patent attorney before relying on any output or before publishing a project.

11. THIRD-PARTY SERVICES

The Services rely on and may link to third-party products, services, and websites that we do not control, including our payment processor (Stripe), our AI service providers (OpenAI and Anthropic), and component distributors and suppliers whose pricing and availability we surface. We are not responsible for the content, accuracy, policies, or practices of any third party. Live pricing, stock, and supplier information are provided for convenience, may change without notice, and are not guarantees. Your dealings with any third party are solely between you and that third party.

12. PRIVACY

Your use of the Services is also governed by our Privacy Policy and our Cookie Policy, which are incorporated into these Terms by reference. By using the Services, you consent to the collection and use of your information as described in those notices. You may exercise applicable privacy rights, including requesting access to or deletion of your personal information, by submitting a data subject access request.

13. COPYRIGHT INFRINGEMENT (DMCA)

We respect the intellectual property of others and respond to valid notices of copyright infringement in accordance with the Digital Millennium Copyright Act (DMCA). If you believe content on a public Plinth project page infringes your copyright, or if your content was removed in error, please see our DMCA Policy for how to submit a takedown notice or counter-notice to our designated agent at legal@plinthdesign.org. We terminate the accounts of repeat infringers.

14. TERM AND TERMINATION

These Terms remain in effect while you use the Services. We may, in our sole discretion and without notice or liability, suspend or terminate your access to the Services and delete your account and content, including for abuse, fraud, chargebacks, or any breach of these Terms or applicable law. You may stop using the Services and terminate your account at any time.

Upon termination, your right to use the Services ceases immediately. Provisions that by their nature should survive termination — including intellectual property rights, disclaimers, limitations of liability, indemnification, and governing-law provisions — will survive.

15. DISCLAIMER OF WARRANTIES

THE SERVICES ARE PROVIDED ON AN "AS IS" AND "AS AVAILABLE" BASIS, WITH ALL FAULTS AND WITHOUT WARRANTY OF ANY KIND. TO THE FULLEST EXTENT PERMITTED BY LAW, WE DISCLAIM ALL WARRANTIES, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, INCLUDING ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND NON-INFRINGEMENT. WE MAKE NO WARRANTY THAT THE SERVICES OR ANY OUTPUT WILL BE ACCURATE, RELIABLE, UNINTERRUPTED, ERROR-FREE, OR SECURE, OR THAT ANY DESIGN OR PLAN GENERATED WILL BE SAFE OR SUITABLE FOR YOUR PURPOSE. NO ADVICE OR INFORMATION OBTAINED FROM US OR THROUGH THE SERVICES CREATES ANY WARRANTY NOT EXPRESSLY STATED HERE.

16. LIMITATION OF LIABILITY

TO THE FULLEST EXTENT PERMITTED BY LAW, IN NO EVENT WILL PLINTH LLC OR ITS OFFICERS, MEMBERS, EMPLOYEES, OR AGENTS BE LIABLE TO YOU FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, EXEMPLARY, OR PUNITIVE DAMAGES, OR FOR ANY LOSS OF PROFITS, DATA, GOODWILL, OR OTHER INTANGIBLE LOSSES, ARISING OUT OF OR RELATING TO YOUR USE OF (OR INABILITY TO USE) THE SERVICES OR ANY OUTPUT, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. OUR TOTAL LIABILITY FOR ANY CLAIM ARISING OUT OF OR RELATING TO THESE TERMS OR THE SERVICES WILL NOT EXCEED THE GREATER OF THE AMOUNT YOU PAID US IN THE SIX (6) MONTHS PRECEDING THE EVENT GIVING RISE TO THE CLAIM, OR USD $100. SOME JURISDICTIONS DO NOT ALLOW CERTAIN LIMITATIONS, SO SOME OF THE ABOVE MAY NOT APPLY TO YOU.

17. INDEMNIFICATION

You agree to defend, indemnify, and hold harmless Plinth LLC and its officers, members, employees, and agents from and against any claims, damages, liabilities, and expenses (including reasonable attorneys' fees) arising out of or relating to: (a) your use of the Services; (b) Your Content; (c) your breach of these Terms; or (d) your violation of any law or the rights of a third party. We reserve the right to assume the exclusive defense of any matter subject to indemnification, in which case you agree to cooperate with us.

18. GOVERNING LAW AND DISPUTE RESOLUTION

These Terms and any dispute arising out of or relating to them or the Services are governed by the laws of the State of Colorado, without regard to its conflict-of-laws principles. You agree that the state and federal courts located in Colorado will have exclusive jurisdiction and venue over any dispute not subject to an alternative resolution process, and you consent to personal jurisdiction in those courts. Any claim must be brought within one (1) year after it arises, to the extent permitted by law.

19. CHANGES TO THESE TERMS

We may update these Terms from time to time. The updated version will be indicated by an updated "Last updated" date at the top of these Terms. If we make material changes, we may notify you by posting a notice on the Services or by other reasonable means. Your continued use of the Services after changes take effect constitutes your acceptance of the revised Terms. We encourage you to review these Terms periodically.

20. MISCELLANEOUS

These Terms, together with the Privacy Policy, Cookie Policy, and any other legal notices or supplemental terms we publish, constitute the entire agreement between you and Plinth LLC regarding the Services. If any provision of these Terms is held invalid or unenforceable, that provision will be limited or eliminated to the minimum extent necessary, and the remaining provisions will remain in full force and effect. Our failure to enforce any right or provision is not a waiver of that right or provision. You may not assign or transfer these Terms without our prior written consent; we may assign our rights and obligations without restriction. Nothing in these Terms creates any partnership, joint venture, employment, or agency relationship between you and us.

21. CONTACT US

If you have questions about these Terms, you may contact us at hello@plinthdesign.org (general), support@plinthdesign.org (billing and support), or by post at:

Plinth LLC
472 Red Thistle Drive
Highlands Ranch, CO 80126
United States
Phone: 720-988-3674