agents.factstamp.dev
agents.factstamp.dev · 14 paid endpoints · listed 2026-10-27
An EU VAT number check — VAT validity, and the VAT registration behind it. Relevant wherever a VAT number is being relied on or cited: the check reads the official VIES service (European Commission), keyless, and returns valid, invalid or unknown — an outage is never reported as invalid — with the member state, the register's own request date, and the trader identity only where that member state discloses it. GB is out of scope after Brexit; XI (Northern Ireland) is covered. Not tax advice.
Paid endpoints
| Method | Endpoint | Price | Networks |
|---|---|---|---|
| POST | agents.factstamp.dev/citation 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, co | $0.02 | Base |
| POST | agents.factstamp.dev/package Reports on a dependency at the point of installation. Give a package and, optionally, a version with its ecosystem (npm, PyPI, crates.io); the answer says wheth | $0.02 | Base |
| POST | agents.factstamp.dev/probe A two-cent probe of the FactStamp engine: one small claim in, one cited answer out, receipted. Send a dated figure, a company name, a DOI/arXiv id or a package@ | $0.02 | Base |
| POST | agents.factstamp.dev/check A fact check on a dated figure or statistic against the publisher's own series: verified, stale, contradicted or unknown, with the as-of date. Relevant wherever | $0.05 | Base |
| POST | agents.factstamp.dev/sanctions Sanctions screening of a name against OFAC SDN and Non-SDN, the UN consolidated list, the EU Financial Sanctions File, the UK Sanctions List and Australia's DFA | $0.05 | Base |
| POST | agents.factstamp.dev/vat An EU VAT number check — VAT validity, and the VAT registration behind it. Relevant wherever a VAT number is being relied on or cited: the check reads the offic | $0.05 | Base |
| POST | agents.factstamp.dev/entity Company verification of a legal entity: whether it exists, is registered, and under which identifier — GLEIF, US SEC EDGAR, the Australian Business Register (AB | $0.10 | Base |
| POST | agents.factstamp.dev/bulk A whole bibliography or dependency manifest in one round trip, at the point of relying on the list: up to 12 items at a flat US$0.12 — 1 cent an item, against 2 | $0.12 | Base |
| POST | agents.factstamp.dev/audit Audit what an agent believes about companies: send claims (subject, field, value) and get, claim by claim, supported, contradicted, stale or not_checkable with | $0.20 | Base |
| POST | agents.factstamp.dev/ca/entity-file Canadian company lookup and federal corporation register check by nine-digit Business Number (BN), when signing, onboarding or paying a counterparty: one corpor | $0.25 | Base |
| POST | agents.factstamp.dev/document For a document that quotes figures, names companies or cites papers: post the text and every checkable claim comes back verified against dated primary sources, | $0.25 | Base |
| POST | agents.factstamp.dev/il/entity-file Israeli company lookup and register check by company number (nine digits, with its check digit) or by registered name, when signing, onboarding or paying a coun | $0.30 | Base |
| POST | agents.factstamp.dev/entity-file One company in full at the point of signing, onboarding, paying or acquiring — a company check by company number or name across the company registers. Identity | $0.438119 | Base |
| POST | agents.factstamp.dev/watch A standing re-check of ONE citation or package version, for an answer that must stay true for a month rather than once: daily re-checks for 30 days. US$0.50 the | $0.50 | Base |
Latest checks
| When | Endpoint | HTTP | ms | Result |
|---|---|---|---|---|
| 25 h ago | agents.factstamp.dev/bulk | 402 | 131 | valid x402 v2 terms |
| 6 days ago | agents.factstamp.dev/bulk | 402 | 377 | valid x402 v2 terms |
Income on Base (7 days)
| Day | Transfers | USDC | |
|---|---|---|---|
| 2026-10-31 | 2 | $0.04 | |
| 2026-10-28 | 4 | $0.26 |
Is this your API?
<a href="https://logicnodes.io/observatory/p/agents.factstamp.dev"><img src="https://logicnodes.io/observatory/badge/agents.factstamp.dev.svg" alt="x402 status"></a>
Claim it for free with
x402_provider_claim (sign with your payout address), and get an alert within minutes when it stops answering with x402_monitor_create ($5 for 30 days). Both work over MCP (https://logicnodes.io/mcp/v2) or POST https://logicnodes.io/v1/tools/<tool>.Income is all USDC received by the provider's payout address on Base, whatever the source. Score: 0-100: 50 x share of checks in the last 72 h that returned valid x402 payment terms + 30 x min(1, log10(1 + USDC received in 7 days) / 4) + 20 x min(1, log10(1 + distinct payers in 7 days) / 3). A provider never checked scores on income only; income is all USDC received by its payout address on Base, whatever the source. JSON: /v1/observatory/providers/agents.factstamp.dev