The short version
lacunos is an AI tutor for biomedical exam prep. You can use the free tools without signing up. To use the full tutor or buy a pass, you create an account. The tutor is helpful but not infallible — double-check anything that feels off. It is a study aid, not medical advice, and not a substitute for licensed instruction. Be a reasonable user; we'll be a reasonable operator. If we ever change these terms, we'll tell you.
1. Acceptance
By creating an account, buying a pass, or using lacunos in any other way, you agree to these Terms of Service ("Terms") and to our Privacy Policy. If you don't agree, don't use the service.
You must be at least 13 years old to use lacunos. lacunos is built for adults preparing for US biomedical exams (MCAT and USMLE Step 1).
2. What lacunos is
lacunos ("we", "us") is an AI-powered tutor for biomedical exam preparation. The tutor uses large language models (currently Anthropic Claude) to teach by probing your understanding, catching misconceptions, and tracking your progress against a canonical exam content map. We also offer free tools such as the Anki Report, which analyzes an uploaded Anki deck to surface coverage and gap patterns.
lacunos is offered "as is." We are continuously improving the product; features may be added, changed, or removed.
3. AI content disclaimer
The tutor's responses, the Anki Report, and any other AI-generated content lacunos produces ("Generated Content") can be inaccurate, incomplete, or out of date. Large language models occasionally produce confident-sounding but wrong answers — especially on edge cases, niche facts, recent guideline changes, or anything outside their training data.
Generated Content is not medical advice. It is not a substitute for licensed clinical instruction, professional study resources, your medical school curriculum, or the published exam blueprints. Do not rely on lacunos for clinical decisions or patient care.
Before you take an exam or use anything you learned here in a clinical setting, verify the material against trusted study resources (e.g., First Aid, UWorld, Pathoma, your course materials) and your school's faculty. If something the tutor says feels off, it might be — check.
4. Your account
To use the full tutor, you create an account through our identity provider, Clerk. You are responsible for:
- Keeping your login credentials secure.
- The activity that happens under your account.
- Providing accurate information at signup (a working email, your real name if you choose to provide one).
One account per person. Don't share your account with others or let others sign in as you. If you suspect your account has been compromised, email us at hello@lacunos.com.
5. Passes, payments, and refunds
How passes work
Paid access to the tutor is sold as a time-limited "pass" — currently 7-day, 30-day, and 3-month durations. A pass gives you tutor access for the duration shown at checkout, starting from the moment of purchase.
No auto-renewal
Passes do not auto-renew. When your pass expires, you keep your account and your conversation history, but tutor access pauses until you buy another pass.
Payment processing
Payments are processed by Stripe. We never see or store your full card number. You authorize the charge at checkout; Stripe handles the rest.
Refunds
Because passes are short, instantly-activated, and metered access to AI compute, all sales are final by default. If something genuinely went wrong on our end — the service was unavailable, you were double-charged, the tutor was unusable due to a bug — email hello@lacunos.com and we'll make it right (refund or pass extension, our choice).
Free tools
The Anki Report and any other free tools are free to use without an account. We may rate-limit, restrict, or change them at any time.
6. Acceptable use
Don't:
- Use lacunos to do anything illegal, harmful, or in violation of someone else's rights.
- Try to extract our prompts, system instructions, material map, or other proprietary content.
- Scrape, mirror, or republish substantial portions of the tutor's output.
- Resell access to lacunos or share your account credentials.
- Use the service to train a competing model on lacunos outputs.
- Attack, probe, or attempt to disrupt the service (rate-bypass, brute force, denial of service).
- Upload Anki decks containing illegal content or content you don't have the right to share.
We may suspend or terminate accounts that violate these rules.
7. Your content
You retain ownership of the content you submit — your messages to the tutor, the Anki decks you upload, your notes. By submitting content, you grant us a limited license to store, process, and display it for the purpose of providing the service to you (e.g., generating tutor replies, building your report, surfacing your gaps).
We don't use your content to train shared AI models. The Anthropic API we route through does not use API inputs for model training by default, and we don't opt in. See our Privacy Policy for the full picture of how your data is handled.
Generated Content the tutor produces during your sessions is yours to keep and use — including the Anki cards generated from misconception catches.
8. Our content
The lacunos product, brand, code, prompts, exam material maps, Anki Report layout, and other proprietary materials are owned by us. You can use the service. You can't copy or repurpose our underlying assets.
9. Service availability
We aim for high availability but don't guarantee uninterrupted service. The tutor depends on upstream AI providers, and there will be occasional slowdowns, errors, or maintenance windows. If a major outage affects your paid pass, contact us and we'll extend or refund as appropriate.
10. Disclaimer of warranties
lacunos is provided "as is" and "as available," without warranties of any kind, express or implied, including merchantability, fitness for a particular purpose, accuracy, or non-infringement. We don't warrant that the service will be error-free, that Generated Content will be accurate, or that the tutor will be available when you want it.
11. Limitation of liability
To the maximum extent permitted by law, lacunos and its operators are not liable for indirect, incidental, consequential, or punitive damages arising out of your use of the service. Our total liability to you for any claim related to lacunos is limited to the amount you paid us in the 12 months preceding the claim. If you used only the free tools, that amount is zero.
Some jurisdictions don't allow limits on certain damages; in those places, our liability is limited to the maximum extent permitted by law.
12. Termination
You can stop using lacunos at any time and request account deletion by emailing hello@lacunos.com. We may suspend or terminate accounts that violate these Terms, abuse the service, or fail to pay. On termination, your right to use the service ends; account data handling follows our Privacy Policy.
13. Changes
We may update these Terms from time to time. When we do, we'll update the "Effective" date at the top. Material changes that affect your rights or obligations will be communicated by email or in-app notice before they take effect. Continued use of the service after the effective date constitutes acceptance of the updated Terms.
14. Governing law
These Terms are governed by the laws of the jurisdiction where lacunos operates, without regard to conflict-of-laws principles. Disputes arising under these Terms will be resolved in good faith first; if that fails, in the courts of competent jurisdiction in that location.
15. Contact
Questions about these Terms? Email hello@lacunos.com.