Painters keep sketches.
Writers should keep foul papers.
Write here. Every keystroke-level change is logged with a time, chained with SHA-256, and kept on this device. Later, replay the whole draft or hand over a proof file anyone can check.
Scope: it proves the history of text written in this page is unedited since export. It cannot prove who was at the keyboard, and timestamps come from your clock.
First proof file free, then £9.00 once. Writing, replay, verifying and the sample are free.
Saved automatically in this browser. Your writing is not uploaded.
Replay
Verify a proof file
Drop a .foulpapers.json file. The chain is recomputed in your browser: if a single character of history was edited, it breaks.
What this does and doesn't prove: the chain shows the history is internally consistent and was not edited afterwards. Timestamps come from the writer's clock; to pin them, publish the final fingerprint somewhere dated (email it to yourself, post it, commit it).
FAQ
What does it do?
You write in the page and every change is logged with a time and chained with SHA-256. You can replay the draft, download a proof file, and check a proof file later to see if its history was edited.
Is my data uploaded?
No. Your writing and its log are kept on this device, in your browser's storage, and are never uploaded. Verifying a proof file also happens in your browser. The page also loads a small shared script that keeps an anonymous page-view and free-use count, plus anonymous error reports. Payment goes through Stripe on Stripe's own page. Clearing your browser data deletes the log, so download the proof file to keep a copy.
What does it cost?
First proof file free, then £9.00 once. That unlocks more proof files and the printable certificate. Writing, replay and verifying stay free.
Refunds?
Digital goods: access starts straight away, so the 14-day cancellation right ends once you start using it. If something is broken, email business@thatched.ai.
Which browsers and devices?
A recent browser on a phone or computer. It needs JavaScript, local storage and the browser's built-in SHA-256 (it works on https pages).