factstamp.agentrails.workers.dev

Call it before you send, file or publish a document that quotes figures, names companies or cites papers. Post the text and every checkable claim comes back verified against dated primary sources, as one signed bundle with a per-claim receipt and its licence. Claims we cannot answer are named and never charged, and the preview is free. Verdicts: verified, stale, contradicted, unknown.

Open endpoint ↗

Price per call: $0.25
Chain: Base
Method: POST
Paid calls · 30 days: 1

Call it from code

This API is run by its own provider and paid directly through x402. We list it so you can find it; we don't route or hold the payment.

import { x402Client, wrapFetchWithPayment } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";

const client = new x402Client();
registerExactEvmScheme(client, { signer: agentAccount });

const pay = wrapFetchWithPayment(fetch, client);
const res = await pay("https://factstamp.agentrails.workers.dev/document", { method: "POST" });
console.log(await res.json());

https://factstamp.agentrails.workers.dev/document