Terms of use

Backfill is a personal project, built by Rutwik Pasumarthi and put online for anyone who wants to give it a try. It takes a paper, a document or a stated goal, works backwards to what it assumes you already know, and writes lessons for the gap. Using it means agreeing to what is on this page.

It is free, non-commercial, and offered as-is. Nothing is for sale, there are no ads and no payments are taken. There is no company behind it, no support commitment, and no promise that it will still be running next month.

Every lesson, quiz, definition and answer is generated by a language model. Models state incorrect things fluently and confidently, and nothing here has been reviewed by a person before you read it. Treat it as a study aid that is often useful and sometimes mistaken, not as a source of truth.

Do not rely on it for anything that matters — not for medical, legal, financial or safety decisions, and not as a citable reference. Check anything important against the source material.

You are responsible for what happens under your account and for keeping your sign-in details to yourself. Tell me if you think someone else has access to it.

You keep ownership of everything you paste, upload or type. By submitting it you confirm you have the right to do so, and you give permission to process it for the purpose of teaching you — which includes sending it to the model providers listed in the privacy policy.

Do not upload material you have no right to share, anything unlawful, or anything containing other people's personal information. If you hold the rights to something and it has been uploaded here without your permission, email rutwikpasumarthi@gmail.com and it will be removed.

This is the part worth reading twice. Lessons are written once per concept and then reused by everyone — that is what keeps the project affordable to run. A lesson generated because you asked for it is stored in a shared library and served to other people learning the same thing.

Those lessons are about the concept, not about you: they do not contain your name, your email or your progress. But they are derived from what you submitted, so do not paste anything confidential.

Generating a lesson costs real money, paid by one person for everybody. Free use is therefore capped, and the limits are shown in the app. Ask if you want them lifted.

Automated or bulk use, attempts to get around the limits, and anything that degrades the service for other people are not allowed.

Backfill is provided as-is, with no warranties of any kind. It may be unavailable, lose data, or produce nonsense.

To the fullest extent the law allows, Rutwik Pasumarthi is not liable for any loss or damage arising from your use of it — including anything that follows from acting on something a model wrote.

You can stop using it whenever you like and ask for your account and data to be deleted by emailing rutwikpasumarthi@gmail.com. Accounts that break these terms may be suspended or removed.

These terms may change. The date at the top says when they last did. Continuing to use Backfill after a change means accepting the new version.

Questions about any of this: rutwikpasumarthi@gmail.com.