Every source in your report re-fetched, content-hashed and timestamped — before you signed it, provably. The record is sealed in a hash chain, so it could not have been made afterwards.
Expert report — draft 4
Ambient particulate levels at the site exceeded the interim guideline in each of the four quarters under review, and the deposition rate recorded on the eastern boundary was roughly double the regional mean (Regional Air Quality Board, 2024, Table 6)1.
The monitoring programme describes its own record as provisional, and the boundary figure quoted above appears there as a range rather than as a single value (Site Monitoring Programme, 2023, p. 41)2 — which I address in section 7.
A comparable result was reported for the neighbouring catchment two years earlier (Halloran & Weir, 2022)3.
The provincial register holds the underlying returns for both years, filed by the operator itself (Provincial Emissions Register, filing 8841)4.
A local bulletin published the same figures in summary form the following spring (Catchment Trust bulletin, March 2024)5.
An illustration, not a screenshot: the five ways a citation can come back, drawn on an invented page. Green appears once, and only where the source resolved and the quote was read back out of it.
Your client's material never leaves your side. The receipt publishes hashes, counts and times — never the text.
Anyone can verify it with our open-source tool, offline, without contacting us.
We do not certify your conclusions. We certify that you checked, and when. That is the part you cannot reconstruct later.
Live
Drop a report. Watch it get checked.
Every source re-fetched, content-hashed and timestamped. Your document is discarded seconds after upload; only spans, hashes and counts remain, and they expire too.
This is the shared example: one check of a public court filing, the same for every visitor and read-only. To seal a receipt, upload your own report.
Run the same open-source verifier a stranger would, here in your browser. With a check above, it reads a preview receipt built from that check — unsigned and unchained, a preview, not sealed.
verifying:the example receipt, sealed under a test key
A preview carries no signature yet: the signature check is expected to fail until the report is sealed. Everything else — the hashes, the counts, the shape — is what the sealed receipt will carry.
requests to us during verification: 0
Running the TypeScript verifier (the wasm build was not reachable); the result is the same shape.
The full sealed file (the creator's download) is the complete record; a receipt's public page carries its signed projection, which verifies on its own.
Sceptical? Open DevTools → Network, clear it, and press Recheck. You will see the one-off verifier download and one anonymous event saying a verification ran and whether it passed. The receipt you pasted is in neither.
Change one byte
Edit the receipt. The moment a sealed byte changes, its hash no longer matches and the signature stops verifying — which is the whole point.
The honest part
What this cannot do
EXISTS
the cited source resolves; we re-fetched it, hashed the bytes and asked an archive to keep a copy. Near-deterministic.
SAYS
the source contains the words you attributed to it, anchored to character offsets. Near-deterministic.
HOLDS
an adversarial attempt to refute the claim, judged by a third model. It disagrees with experts often, it returns INSUFFICIENT_EVIDENCE often and on purpose, it is off by default, and it never enters the sealed record.
We do not certify your conclusions. We do not judge contested claims. A receipt will not rescue a litigator in court and is not a claim that anything is true.
Newsrooms and fact-checking desks. They do not pay for this; grants do.
Litigators checking case law. The case-law corpus belongs to the incumbents, and courts have rejected one AI checking another as verification — a receipt will not help you there.
Enterprise AI governance. Vendor review does not fit a self-serve tool run by one person — waitlist above.
EU AI Act compliance programmes.
Advertising substantiation.
Any public badge. A badge on a client report tells the client you used AI and tells their procurement team your score. We will not build one.