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Terms of service

Last updated: 5 November 2026

These terms cover the Jeff website (jeffhub.ai), the Jeff API, the Jeff SDKs and the open adapters. By making an account or using the API, you agree to them.

Who we are

Jeff is run by Casperaki Multimedia Solutions Ltd., a company registered in England and Wales (number 10634954, VAT number GB 278768236), whose registered office is 40 Bank Street, Level 19, London, E14 5NR, England. In these terms, "we" and "us" mean that company. "You" means the person or organisation using Jeff.

You can reach us at mstrasser@scissero.com.

Your account

  • You sign in with a link sent to your email, or with Google or GitHub. We do not use passwords.
  • You must be at least 18 to make an account.
  • A company or other organisation may hold an account. If you sign up on its behalf, you confirm that you may bind it to these terms.
  • Keep access to your email account and your sign-in safe. What is done with your account is your responsibility.
  • You can delete your account at any time on your account page. The privacy policy says what that deletes.

API keys

  • You can hold up to 10 live API keys. We show each key once, when you make it. We keep only a fingerprint of it, so we cannot show it again.
  • Keep your keys secret. Calls made with your key count against your allowance, whoever makes them.
  • If a key leaks, revoke it on your account page. It stops working within about a minute.

The API plan

  • The API plan costs $1 a month and includes 50 million input tokens a month. Every adapter in the catalogue is included.
  • Where VAT or sales tax applies, it is added at checkout.
  • Payments are taken by Stripe. You pay monthly, in advance, from the day you subscribe.
  • When the month's allowance is used up, the API refuses calls until your next billing period starts. You are never charged more than the plan's price.
  • You can cancel at any time, through "Manage billing" on your account page. The plan then runs to the end of the month you have paid for. We do not refund part of a month, unless the law requires it.
  • Deleting your account cancels the plan at once. Part of a month is not refunded, unless the law requires it.
  • We give at least 30 days' notice by email before changing the price.

Running Jeff on your own machine

  • The SDKs, the engine and the open adapters are free to run on your own machine.
  • Each open adapter's weights are published under the licence its catalogue page names (for example Apache-2.0). That licence, not these terms, governs what you may do with the weights.
  • The weights are downloaded from Hugging Face, under Hugging Face's own terms.
  • Running an adapter on your own machine sends nothing to us.

The playground

The playground on this site runs examples through the API for free. Visitors who are not signed in pass a bot check and can make a few runs a minute. We may change these limits or turn the playground off.

Adapter requests

  • You can ask us to build an adapter for your own decision, with examples or a data set. You can have up to 3 requests open, and send up to 5 in any 24 hours.
  • When you send a request, you confirm that you have the right to share its examples, and that they contain no personal data, or that it has been removed.
  • We may decline a request. We do not promise to build an adapter, or to reach a given accuracy.
  • The privacy policy says how we keep and use the examples.
  • You keep the rights in the examples and data you send us. We own the adapter we build from them. It is available only to your account, and we never offer it to anyone else without your consent.
  • Building a requested adapter is priced separately. We tell you the price before we start training, and we start only once you agree.

Acceptable use

Do not use Jeff to:

  • break the law, or help someone else break it;
  • attack, overload or probe the service, or get around its limits or its bot checks;
  • share your API key publicly, or let others use your account in place of their own;
  • You may build products that use Jeff, but you may not resell access to the API itself without our written agreement.

We may suspend or close an account that breaks these rules. Where we can, we tell you first and say why.

Answers can be wrong

Each adapter answers with a probability, and some answers are wrong. The catalogue says how each adapter was measured. Check the answers before you rely on them. Do not use an answer alone for a decision with legal effect on a person, or a similar effect, without a person checking it.

Availability

We aim to keep the API running, but we do not promise it will always be available. We may change, add or remove adapters and features. We do not promise a service level. We give at least 30 days' notice before we withdraw an adapter that a paying customer uses.

Liability

  • The service is provided as it is. Jeff's answers can be wrong: you decide how you use them, and you are responsible for decisions you base on them.
  • Our total liability to you is limited to the amount you paid us in the 12 months before the claim.
  • We are not liable for indirect or consequential losses, or for lost profits, revenue, data or goodwill. Nothing in these terms limits liability that English law does not allow us to limit, such as for fraud, or for death or personal injury caused by negligence.

Changes to these terms

We may change these terms. We will post the new version here and change the date at the top. For a material change, we tell account holders by email at least 30 days before it takes effect.

Law and courts

These terms are governed by the law of England and Wales. Disputes go to the courts of England and Wales.