ToolVet
81trust / 100

Citation

by agents.factstamp.dev in News & content

x402 APIPassing, checked 1 h ago

FactStamp citation check: says whether a citation can be repeated. Give a DOI, an arXiv ID or a paper title; the answer says whether the work exists, what it is (title, authors, year, container) and whether it has been retracted, read from Crossref and arXiv. A title absent from both returns not_found, and a near title match is never reported as verified. Cited to the source record with its retrieval time. Verdicts: verified, ambiguous, retracted, not_found, unknown.

POST
https://agents.factstamp.dev/citation
Price
$0.02
per call in USDC
Uptime
100%
last 30 days
Response time
237 ms
627 ms slowest 5%
Last check
Passed
1 h ago, next any minute now

Run a free test callHow to call it

Reliability

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Status and outage history · Atom feed · Watch with other listings

How to call it

POST https://agents.factstamp.dev/citation

Each call costs $0.02 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

POST https://agents.factstamp.dev/citation
content-type: application/json

{
  "query": "10.1038/nature12373"
}

Example response

The provider's example. We can't check it without paying.

{
  "kind": "doi",
  "query": "10.1038/nature12373",
  "record": {
    "authors": [
      "G. Kucsko",
      "P. C. Maurer",
      "N. Y. Yao"
    ],
    "container": "Nature",
    "doi": "10.1038/nature12373",
    "publisher": "Springer Science and Business Media LLC",
    "retraction": null,
    "title": "Nanometre-scale thermometry in a living cell",
    "type": "journal-article",
    "year": 2013
  },
  "sources": [
    {
      "http_status": 200,
      "name": "Crossref"
    }
  ],
  "verdict": "verified"
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.02.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://agents.factstamp.dev/citation' \
  -H 'content-type: application/json' \
  --data-raw '{"query":"10.1038/nature12373"}'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://agents.factstamp.dev/citation' \
  -H 'content-type: application/json' \
  --data-raw '{"query":"10.1038/nature12373"}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fagents.factstamp.dev%2Fcitation&method=POST
const res = await pay("https://agents.factstamp.dev/citation", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "query": "10.1038/nature12373"
  }),
});
console.log(res.status, await res.text());
Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://agents.factstamp.dev/citation",
        json={
            "query": "10.1038/nature12373",
        },
    )
    print(res.status_code, res.text)

Security scan

No findings

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Recent checks

WhenResultHTTPTimePrice
1 h agoPassed40298 ms$0.02
10 h agoPassed402158 ms$0.02
20 h agoPassed402117 ms$0.02
29 h agoPassed402156 ms$0.02
38 h agoPassed402503 ms$0.02
Show 10 older checks
46 h agoPassed402349 ms$0.02
2 days agoPassed402418 ms$0.02
3 days agoPassed402324 ms$0.02
3 days agoPassed402293 ms$0.02
3 days agoPassed402128 ms$0.02
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