Acceptance of Terms
By using numstack.net or its API (together, "NumStack"), you agree to these terms. If you do not agree, do not use the site or the API.
⚠️ Important Disclaimer
The calculators are informational tools only and are NOT:
- Financial, tax, or investment advice
- A guarantee of actual costs, pay, refunds, or tax liability
- Substitutes for official provider pricing pages or a tax professional
- Binding quotes from providers
Actual results may vary due to:
- API provider pricing changes
- Volume discounts and promotions
- Currency fluctuations
- Model updates or deprecation
- Your individual tax, income, or filing circumstances
Always verify pricing directly with the API provider, and consult a qualified professional before making financial, tax, or infrastructure decisions.
Pro API Subscription
NumStack offers a paid Pro tier for API access, billed monthly. The following applies if you subscribe:
- Subscription billing and payment processing are handled by our third-party payment processor, currently Stripe (through Stripe Managed Payments, which makes Stripe the merchant of record); some purchases may instead be processed by Lemon Squeezy. By subscribing you also agree to the applicable terms of whichever of them processes your payment.
- You may cancel your subscription at any time; cancellation stops future billing but does not retroactively refund the current billing period unless required by law.
- API keys are issued to you personally (or to your organization, for Enterprise plans) and are non-transferable — do not share, sell, or publish your key.
- We may rotate or revoke a key that we reasonably believe has been compromised, shared publicly, or used to violate these terms, and will make reasonable efforts to notify you.
- Rate limits and features for each tier are described on the Pricing page and may be updated from time to time; material reductions will be communicated in advance where practical.
LLM Cost Audit (One-Time Purchase)
NumStack also offers the LLM Cost Audit, a one-time $149 purchase. The following applies:
- What's delivered: a written report covering your current cost model, model-swap options by price band, prompt and caching savings, architecture recommendations, a 30-day action plan, and a projected savings table, built from the usage information you submit on the intake form.
- Our guarantee: If the audit doesn't identify at least $149 a month in savings, email us within 14 days for a full refund.
- The report is an engineering cost estimate based on the information you provide and public list prices — it is not financial, tax, or legal advice, and actual results may vary for the reasons described in the Important Disclaimer above.
- Payment is processed by our third-party payment processor, currently Stripe (merchant of record under Stripe Managed Payments), or by Lemon Squeezy for purchases made through it; refunds under the guarantee above are issued through whichever processor took the payment.
Limitation of Liability
To the fullest extent permitted by law, we are not liable for:
- Damages from reliance on calculator or API results
- Lost revenue or business opportunities
- Incorrect cost, paycheck, or tax estimates
- Server downtime, API downtime, or errors
- Data loss or corruption
Your exclusive remedy is to stop using the site and, if applicable, cancel your subscription.
Use License
We grant you a limited, non-exclusive, revocable license to use the free NumStack calculators for personal or commercial purposes, and to use the Pro or Enterprise API under the terms of your subscription and the rate limits for your tier. This license does not permit reselling or rebranding NumStack itself as your own product.
User Responsibilities
You agree to:
- Use the site and API only for lawful purposes
- Not attempt to harm, disrupt, or reverse-engineer the site or API
- Not scrape or automate data collection outside the documented API and its rate limits
- Keep your API key confidential and not share it with third parties
- Provide accurate information when using calculators
Intellectual Property
All content on NumStack (calculators, text, design, and API responses) is our intellectual property or used with permission.
You may not:
- Copy or reproduce content without permission
- Claim ownership of our calculators or API
- Remove copyright notices
Affiliate Links
Some calculator pages include links to third-party vendors, and some of those links may be affiliate or referral links. We may earn a commission if you sign up or make a purchase through such a link, at no additional cost to you. Affiliate links are marked with a rel="sponsored" attribute. See our Privacy Policy for more detail.
Changes to Terms
We may update these terms from time to time. The "Last updated" date at the top reflects the most recent revision. Continued use of the site or API after a change means acceptance of the updated terms.
Contact
Questions? Email [email protected] or visit our Contact page.