Paste a document. We pull out the claims that can actually be checked against a primary source, check each one, and sign every answer. You get the sentences, the verdicts and the receipts.
Extraction is mechanical, not interpretive: no model reads your document, so the list of claims is reproducible from the document alone and the count is a number you can check. A sentence becomes a claim only when it names something we hold coverage for and carries the value to check. Anything else is reported as considered and left alone.
| Claim | Price |
|---|---|
| A figure or an entity status (a rate, an index, an ABN) | US$0.05 a claim |
| A citation or a package version | US$0.02 a claim |
Priced as the checks it contains, at the same price as calling each door on its own. No bundle premium. Up to 25 claims a document, and a document longer than that says so rather than quietly dropping the rest. A claim we could not answer is not charged for.
The preview lists every claim we can check and the exact price, and costs nothing. Paying to discover a document had nothing checkable in it would be a bad way to find out.
curl -s https://factstamp.agentrails.workers.dev/document -H 'content-type: application/json' -d '{"document":"The cash rate was 3.85% in July 2026. See 10.1038/nature12373.","preview":true}'
curl -s https://factstamp.agentrails.workers.dev/document -H 'authorization: Bearer PACK_CODE' -H 'content-type: application/json' -d '{"document":"The cash rate was 3.85% in July 2026. See 10.1038/nature12373."}'
The answer carries one receipt, signed with our published key, over the document hash
and the receipt of every claim inside it. Verification is offline and free:
GET https://factstamp.agentrails.workers.dev/.well-known/factstamp-issuer.json publishes the key.
Docs · Packs · x402 manifest