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FactStamp verifies a company against official public registers in 15 jurisdictions and returns a dated, cited, machine-readable answer.

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Call it x402 v2

x402 v2

Base URL
https://agents.factstamp.dev
Payment
x402 v2, header channel
$ curl -i -X POST -H 'Content-Type: application/json' -d '"{\"query\":\"Example Holdings Limited\"}"' 'https://agents.factstamp.dev/bulk'

An unpaid request returns HTTP 402 with the payment terms. Sign a payment authorization, then retry with the PAYMENT-SIGNATURE header.

Endpoints 10 paid routes on agents.factstamp.dev

POST/bulkBase$0.12since 10-14
POST/checkBase$0.05since 10-14
POST/citationBase$0.02since 10-14
POST/documentBase$0.25since 10-14
POST/entityBase$0.10since 10-14
POST/entity-fileBase$0.438119since 10-14
POST/packageBase$0.02since 10-14
POST/sanctionsBase$0.05since 10-14

2 more in Example 402 response

Prices as captured in the 402 response: median $0.075 across the 10 endpoints, unchanged since first capture.

Example 402 response

Endpoints and prices

Current paid endpoints; minimum quoted prices in USD where available; first capture dates in UTC
MethodPathDescriptionPriceNetworkAsset402 channelCaptured
POST/bulkCheck a whole bibliography or dependency manifest in one round trip, before you rely on the list: up to 12 items at a flat US$0.12 · 1 cent an item, against 2 cents for the same lookups one at a time. Every item is answered by the same door that answers a single call, so the verdicts cannot disagree. A list, not prose: a whole document belongs to /document. Pay per call here, or redeem a prepaid pack code (one answer-pack credit per three items, up to 25 items on that rail).$0.12BaseUSDCheadersince 10-14
POST/checkCheck a dated figure you are about to act on against the publisher's own series, and receive verified, stale, contradicted or unknown with the as-of date. Call it before committing a number to a page, deck, model or decision. Coverage today is Australian primary sources; anything outside coverage returns unknown rather than a guess.$0.05BaseUSDCheadersince 10-14
POST/citationCheck a citation before repeating it. 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a paper title; the answer says whether the work exists, what it is (title, authors, year, container) and whether it has been retracted. A title that is absent from both Crossref and arXiv 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.$0.02BaseUSDCheadersince 10-14
POST/documentCall 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. Prose, not a list: a bare bibliography belongs to /bulk.$0.25BaseUSDCheadersince 10-14
POST/entityVerify whether a legal entity exists and is currently registered, from open primary registers: the GLEIF LEI index, US SEC EDGAR and the Australian Business Register (ABN, ACN, GST, status). Call it before naming a company in a contract, invoice or filing, or when you need an identifier (ABN, ACN, LEI, CIK) for a company you know only by name. Returns found, ambiguous, not_found or unknown, cited to the register with its retrieval time. A near name match is never reported as a match.$0.10BaseUSDCheadersince 10-14
POST/entity-fileWhen you need the whole picture of one company before you sign, onboard, pay or acquire, call the entity file: ONE answer holding identity and standing, the registered office, SIC activity and previous names, the filing position, a sanctions screen across four lists, and the ownership chain to the ultimate parent · with ONE coverage block naming every register consulted and every one not. One call and one receipt instead of four. Unknown is a first-class answer.$0.438119BaseUSDCheadersince 10-14
POST/packageCheck a dependency before installing it. Give a package and, optionally, a version with its ecosystem (npm, PyPI, crates.io); the answer says whether that exact version exists, whether it is yanked or deprecated, and every advisory OSV lists against it. A version that was never published returns not_found with the real versions nearest to it. Verdicts: verified, advisory, yanked, not_found, unknown.$0.02BaseUSDCheadersince 10-14
POST/sanctionsScreen a name against sanctions lists before you transact with it: is this person or company on OFAC SDN, the UN consolidated list, the EU Financial Sanctions File or the UK Sanctions List? Returns listed, mismatch, not_found or unknown, with the matched entry's own reference (program, country, aliases) and each list's dates. A near name is never reported as the same party, and a list that was not consulted is named as not consulted. Not advice, not a legal determination.$0.05BaseUSDCheadersince 10-14
POST/vatCheck an EU VAT number before you rely on it: is this number a live VAT registration, and who is behind it? Asks the official VIES service (European Commission), keyless. 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.$0.05BaseUSDCheadersince 10-14
POST/watchBuy a standing re-check of ONE citation or package version, when an answer must stay true for a month rather than once: daily re-checks for 30 days. US$0.50 the month · 1.7 cents a check, under a 2-cent lookup. The first check is answered and signed on purchase, and each real change (a retraction, a new advisory, a yanked version) gets its own signed receipt. One subject only: for a list use /watch/portfolio. Pay per call here, or redeem a pack code (10 credits).$0.50BaseUSDCheadersince 10-14

Payment evidence

402 payload captured at . Check evidence JSON · Measurement methodology.

Payload 6 of 10 captured by the monitor for POST /bulk.

121 lines, scroll inside

{
  "error": "No pack code. A bulk call is 0.016667 an item (one credit per three items, up to 25), or pay per call on the x402 rail — US$0.12 for up to 12 items.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
      "amount": "120000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/bulk",
      "description": "Check a whole bibliography or dependency manifest in one round trip, before you rely on the list: up to 12 items at a flat US$0.12 — 1 cent an item, against 2 cents for the same lookups one at a time. Every item is answered by the same door that answers a single call, so the verdicts cannot disagree. A list, not prose: a whole document belongs to /document. Pay per call here, or redeem a prepaid pack code (one answer-pack credit per three items, up to 25 items on that rail).",
      "maxAmountRequired": "120000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://agents.factstamp.dev/bulk"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "packages": [
              "[email protected]"
            ],
            "citations": [
              "10.1038/nature12373",
              "10.1016/s0140-6736(97)11096-0"
            ]
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "items": 3,
            "results": [
              {
                "tool": "verify_citation",
                "input": "10.1038/nature12373",
                "verdict": "verified"
              }
            ],
            "answered": 3,
            "paid_with": {
              "rail": "x402_pay_per_call",
              "settlement": {
                "success": true
              },
              "list_price_usd": 0.12
            },
            "by_verdict": {
              "verified": 2,
              "retracted": 1
            },
            "unreadable": 0,
            "receipt_url": "https://factstamp.agentrails.workers.dev/r/c41e77b2aa90d613"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input",
          "output"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "body": {
                "type": "object"
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              },
              "bodyType": {
                "const": "application/json"
              }
            },
            "additionalProperties": true
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            },
            "additionalProperties": true
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2
}
Other captured 402 responses (9)

Captured payload 1 of 10

{
  "error": "No pack code. Redeem one and send it as a bearer token, or pay per call on the x402 rail.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
      "amount": "438119",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/entity-file",
      "description": "The whole picture of one company before you sign, onboard, pay or acquire: identity and standing, the registered office, SIC and previous names, the filing position, a sanctions screen across five lists, and the ownership the registers publish (the persons with significant control where a register publishes them, and the declared parent relationships where a company has an LEI, with beneficial ownership stated as not public in nearly every country we cover). One receipt, not four calls.",
      "maxAmountRequired": "438119",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://agents.factstamp.dev/entity-file"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "query": "00445790"
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "tool": "check_entity_file",
            "price": {
              "rate": {
                "pair": "USD/GBP",
                "as_of": "2026-10-06",
                "basis": "The conversion basis is the RECORDED reference rate: 2026-10-06 from European Central Bank euro foreign exchange reference rates (via frankfurter.dev), 8.4 days old, past its 7-day window. It is REUSED AND DECLARED STALE rather than refreshed, because the published price is derived from it: a refresh would quote an amount that appears on no published surface.",
                "stale": true,
                "value": 0.75322,
                "source": "European Central Bank euro foreign exchange reference rates (via frankfurter.dev)",
                "age_days": 8.4,
                "source_url": "https://api.frankfurter.dev/v1/latest?base=USD&symbols=GBP"
              },
              "unit": "pence",
              "settled": {
                "usd": 0.438119,
                "currency": "USDC",
                "base_units": "438119"
              },
              "currency": "GBP",
              "list_gbp": "0.33",
              "rounding": {
                "note": "The USDC amount is the pence list price converted at the rate above and rounded DOWN to the nearest base unit, so the buyer is never charged over the quoted price and any rounding falls to the buyer, never to us. The advertised USDC amount is what settles.",
                "direction": "down",
                "exact_usd": 0.43811901
              },
              "list_pence": 33,
              "list_withheld": false,
              "withhold_after_days": 30
            },
            "query": {
              "input": "00445790",
              "jurisdiction": null
            },
            "receipt": {
              "alg": "Ed25519",
              "key_id": "2331751858f5e3b1"
            },
            "verdict": "found",
            "accepted": 1,
            "coverage": {
              "complete": false,
              "consulted": [
                "gleif",
                "uk_snapshot",
                "sdn",
                "cons",
                "un",
                "eu",
                "uk"
              ],
              "not_consulted": [
                "sec",
                "abr"
              ]
            },
            "sections": [
              {
                "n": 1,
                "id": "identity_and_standing",
                "fields": {
                  "status": "Active",
                  "standing": "active",
                  "legal_name": "TESCO PLC",
                  "company_type": "Public Limited Company",
                  "registered_number": "00445790"
                },
                "status": "answered"
              },
              {
                "n": 2,
                "id": "registered_office",
                "fields": {
                  "country": "England",
                  "postcode": "AL7 1GA"
                },
                "status": "answered"
              },
              {
                "n": 3,
                "id": "activity_and_history",
                "fields": {
                  "sic_codes": [
                    "47110 - Retail sale in non-specialised stores"
                  ],
                  "previous_names": []
                },
                "status": "answered"
              },
              {
                "n": 4,
                "id": "filing_position",
                "fields": {
                  "charges": {
                    "registered": 12
                  },
                  "accounts_category": "FULL"
                },
                "status": "answered"
              },
              {
                "n": 5,
                "id": "sanctions",
                "fields": {
                  "verdict": "not_found"
                },
                "status": "answered"
              },
              {
                "n": 6,
                "id": "ownership",
                "fields": {
                  "verdict": "found",
                  "parent_statement": "…"
                },
                "status": "answered"
              },
              {
                "n": 7,
                "id": "coverage",
                "fields": {
                  "complete": false,
                  "not_consulted": [
                    "sec",
                    "abr"
                  ]
                },
                "status": "answered"
              }
            ],
            "receipt_url": "https://factstamp.agentrails.workers.dev/r/c41e77b2aa90d613",
            "file_version": 1
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input",
          "output"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "body": {
                "type": "object"
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              },
              "bodyType": {
                "const": "application/json"
              }
            },
            "additionalProperties": true
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            },
            "additionalProperties": true
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2
}

Captured payload 2 of 10

{
  "error": "No pack code. Redeem one and send it as a bearer token, or pay per call on the x402 rail.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
      "amount": "50000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/check",
      "description": "Check a dated figure you are about to act on against the publisher's own series, and receive verified, stale, contradicted or unknown with the as-of date. Call it before committing a number to a page, deck, model or decision. Coverage today is Australian primary sources; anything outside coverage returns unknown rather than a guess.",
      "maxAmountRequired": "50000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://agents.factstamp.dev/check"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "claim": "The RBA cash rate is 4.35% as at August 2026"
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "as_of": "2026-08-01",
            "claim": "The RBA cash rate is 4.35% as at August 2026",
            "verdict": "contradicted",
            "publisher": "Reserve Bank of Australia",
            "series_id": "rate.rba_cash_target"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input",
          "output"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "body": {
                "type": "object"
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              },
              "bodyType": {
                "const": "application/json"
              }
            },
            "additionalProperties": true
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            },
            "additionalProperties": true
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2
}

Captured payload 3 of 10

{
  "error": "No pack code. Redeem one and send it as a bearer token, or pay per call on the x402 rail.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
      "amount": "20000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/citation",
      "description": "Check a citation before repeating it. 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. A title that is absent from both Crossref and arXiv 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.",
      "maxAmountRequired": "20000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://agents.factstamp.dev/citation"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "query": "10.1038/nature12373"
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "kind": "doi",
            "query": "10.1038/nature12373",
            "record": {
              "doi": "10.1038/nature12373",
              "type": "journal-article",
              "year": 2013,
              "title": "Nanometre-scale thermometry in a living cell",
              "authors": [
                "G. Kucsko",
                "P. C. Maurer",
                "N. Y. Yao"
              ],
              "container": "Nature",
              "publisher": "Springer Science and Business Media LLC",
              "retraction": null
            },
            "sources": [
              {
                "name": "Crossref",
                "http_status": 200
              }
            ],
            "verdict": "verified"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input",
          "output"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "body": {
                "type": "object"
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              },
              "bodyType": {
                "const": "application/json"
              }
            },
            "additionalProperties": true
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            },
            "additionalProperties": true
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2
}

Captured payload 4 of 10

{
  "error": "No pack code. Redeem one with a bearer token, or pay per call on the x402 rail.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
      "amount": "100000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/entity",
      "description": "Verify whether a legal entity exists and is currently registered, from open primary registers: the GLEIF LEI index, US SEC EDGAR and the Australian Business Register (ABN, ACN, GST, status). Call it before naming a company in a contract, invoice or filing, or when you need an identifier (ABN, ACN, LEI, CIK) for a company you know only by name. Returns found, ambiguous, not_found or unknown, cited to the register with its retrieval time. A near name match is never reported as a match.",
      "maxAmountRequired": "100000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://agents.factstamp.dev/entity"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "query": "Shopify Inc."
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "best": {
              "id": "549300HGQ43STJLLP808",
              "name": "SHOPIFY INC.",
              "source": "gleif",
              "jurisdiction": "CA-ON",
              "registration_status": "ISSUED"
            },
            "query": "Shopify Inc.",
            "sources": [
              {
                "source": "gleif",
                "licence": "CC0 1.0 Universal",
                "http_status": 200
              }
            ],
            "verdict": "found",
            "accepted": 1
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input",
          "output"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "body": {
                "type": "object"
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              },
              "bodyType": {
                "const": "application/json"
              }
            },
            "additionalProperties": true
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            },
            "additionalProperties": true
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2
}

Captured payload 5 of 10

{
  "error": "No pack code. Redeem one and send it as a bearer token, or pay per call on the x402 rail.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
      "amount": "20000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/package",
      "description": "Check a dependency before installing it. Give a package and, optionally, a version with its ecosystem (npm, PyPI, crates.io); the answer says whether that exact version exists, whether it is yanked or deprecated, and every advisory OSV lists against it. A version that was never published returns not_found with the real versions nearest to it. Verdicts: verified, advisory, yanked, not_found, unknown.",
      "maxAmountRequired": "20000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://agents.factstamp.dev/package"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "package": "[email protected]",
            "ecosystem": "npm"
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "name": "express",
            "query": "[email protected]",
            "detail": "2 advisory record(s) published against [email protected].",
            "latest": "5.2.1",
            "yanked": false,
            "sources": [
              {
                "name": "npm registry",
                "http_status": 200
              },
              {
                "name": "OSV",
                "http_status": 200
              }
            ],
            "verdict": "advisory",
            "version": "4.18.2",
            "ecosystem": "npm",
            "advisories": [
              {
                "id": "GHSA-qw6h-vgh9-j6wx"
              },
              {
                "id": "GHSA-rv95-896h-c2vc"
              }
            ],
            "deprecated": null,
            "published_at": "2022-10-08T20:14:32.495Z"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input",
          "output"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "body": {
                "type": "object"
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              },
              "bodyType": {
                "const": "application/json"
              }
            },
            "additionalProperties": true
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            },
            "additionalProperties": true
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2
}

Captured payload 7 of 10

{
  "error": "No pack code. Redeem one with `authorization: Bearer *** or pay per call on the x402 rail. This preview is free: POST the same body with \"preview\": true to see the claims and the price first.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
      "amount": "250000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/document",
      "description": "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. Prose, not a list: a bare bibliography belongs to /bulk.",
      "maxAmountRequired": "250000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://agents.factstamp.dev/document"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "document": "The RBA cash rate was 4.35% as at August 2026. Shopify Inc. is registered in Canada. The method follows doi:10.1038/nature12373."
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "claims": [
              {
                "kind": "figure",
                "as_of": "2026-08-01",
                "claim": "The RBA cash rate was 4.35% as at August 2026",
                "source": "Reserve Bank of Australia",
                "verdict": "contradicted"
              },
              {
                "kind": "entity",
                "as_of": "2026-10-06",
                "claim": "Shopify Inc. is registered in Canada",
                "source": "GLEIF",
                "verdict": "verified"
              }
            ],
            "receipt": "eyJhbGciOiJFZERTQSJ9…",
            "unknown": 1,
            "answered": 2,
            "claims_found": 3,
            "charged_credits": 2,
            "document_sha256": "9f2c…"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input",
          "output"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "body": {
                "type": "object"
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              },
              "bodyType": {
                "const": "application/json"
              }
            },
            "additionalProperties": true
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            },
            "additionalProperties": true
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2
}

Captured payload 8 of 10

{
  "error": "No pack code. Redeem one and send it as a bearer token, or pay per call on the x402 rail.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
      "amount": "50000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/sanctions",
      "description": "Screen a name against sanctions lists before you transact with it: is this person or company on OFAC SDN, the UN consolidated list, the EU Financial Sanctions File or the UK Sanctions List? Returns listed, mismatch, not_found or unknown, with the matched entry's own reference (program, country, aliases) and each list's dates. A near name is never reported as the same party, and a list that was not consulted is named as not consulted. Not advice, not a legal determination.",
      "maxAmountRequired": "50000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://agents.factstamp.dev/sanctions"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "kind": "entity",
            "name": "Banco Nacional de Cuba",
            "country": "CU"
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "tool": "check_sanctions",
            "match": {
              "list": "SDN",
              "name": "BANCO NACIONAL DE CUBA",
              "aliases": [
                {
                  "name": "NATIONAL BANK OF CUBA",
                  "type": "a.k.a."
                }
              ],
              "ent_num": "306",
              "program": "CUBA",
              "countries": [
                "Cuba"
              ],
              "matched_via": "primary",
              "matched_name": "BANCO NACIONAL DE CUBA",
              "retrieved_at": "2026-10-06T14:43:53.048Z"
            },
            "query": {
              "kind": "entity",
              "name": "Banco Nacional de Cuba",
              "country": "CU"
            },
            "receipt": {
              "alg": "Ed25519",
              "key_id": "2331751858f5e3b1"
            },
            "verdict": "listed",
            "coverage": {
              "complete": true,
              "consulted": [
                "sdn",
                "cons",
                "un",
                "eu",
                "uk"
              ],
              "not_consulted": []
            },
            "receipt_url": "https://factstamp.agentrails.workers.dev/r/c41e77b2aa90d613"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input",
          "output"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "body": {
                "type": "object"
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              },
              "bodyType": {
                "const": "application/json"
              }
            },
            "additionalProperties": true
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            },
            "additionalProperties": true
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2
}

Captured payload 9 of 10

{
  "error": "No pack code. Redeem one and send it as a bearer token, or pay per call on the x402 rail.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
      "amount": "50000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/vat",
      "description": "Check an EU VAT number before you rely on it: is this number a live VAT registration, and who is behind it? Asks the official VIES service (European Commission), keyless. 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.",
      "maxAmountRequired": "50000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://agents.factstamp.dev/vat"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "vat_number": "6388047V",
            "country_code": "IE"
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "tool": "check_vat",
            "check": {
              "isValid": true,
              "userError": "VALID",
              "vat_number": "6388047V"
            },
            "query": {
              "vat_number": "6388047V",
              "country_code": "IE"
            },
            "scope": "in_scope",
            "source": {
              "source": "VIES (European Commission)",
              "licence": "CC BY 4.0 (European Commission reuse policy, Decision 2011/833/EU)",
              "request_date": "2026-10-07T07:40:59.315Z",
              "member_state_code": "IE",
              "consultation_number": {
                "available": false
              }
            },
            "trader": {
              "name": "GOOGLE IRELAND LIMITED",
              "address": "3RD FLOOR, GORDON HOUSE, BARROW STREET, DUBLIN 4",
              "identity_disclosed": true
            },
            "country": {
              "code": "IE",
              "name": "Ireland",
              "in_vies": true
            },
            "receipt": {
              "alg": "Ed25519",
              "key_id": "2331751858f5e3b1"
            },
            "verdict": "valid",
            "coverage": {
              "complete": true,
              "consulted": [
                "vies"
              ],
              "not_consulted": []
            },
            "receipt_url": "https://factstamp.agentrails.workers.dev/r/c41e77b2aa90d613"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input",
          "output"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "body": {
                "type": "object"
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              },
              "bodyType": {
                "const": "application/json"
              }
            },
            "additionalProperties": true
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            },
            "additionalProperties": true
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2
}

Captured payload 10 of 10

{
  "error": "No pack code. A watch is US$0.5 (10 credits); buy a pack, or pay per call on the x402 rail.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
      "amount": "500000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/watch",
      "description": "Buy a standing re-check of ONE citation or package version, when an answer must stay true for a month rather than once: daily re-checks for 30 days. US$0.50 the month — 1.7 cents a check, under a 2-cent lookup. The first check is answered and signed on purchase, and each real change (a retraction, a new advisory, a yanked version) gets its own signed receipt. One subject only: for a list use /watch/portfolio. Pay per call here, or redeem a pack code (10 credits).",
      "maxAmountRequired": "500000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://agents.factstamp.dev/watch"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "kind": "citation",
            "subject": "10.1038/nature12373",
            "webhook": "https://example.com/factstamp/hook"
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "kind": "citation",
            "token": "fw_9d1c… (shown once)",
            "subject": "10.1038/nature12373",
            "read_url": "https://factstamp.agentrails.workers.dev/watch/9f2c1ab4d0e57718",
            "watch_id": "9f2c1ab4d0e57718",
            "paid_with": {
              "rail": "x402_pay_per_call",
              "settlement": {
                "success": true
              },
              "list_price_usd": 0.5
            },
            "expires_at": "2026-11-05T06:30:00.000Z",
            "receipt_url": "https://factstamp.agentrails.workers.dev/r/8bd1f0a4c9e27715",
            "next_check_at": "2026-10-07T06:30:00.000Z",
            "seeded_verdict": "verified"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input",
          "output"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "body": {
                "type": "object"
              },
              "type": {
                "const": "http"
              },
              "method": {
                "const": "POST"
              },
              "bodyType": {
                "const": "application/json"
              }
            },
            "additionalProperties": true
          },
          "output": {
            "type": "object",
            "required": [
              "type",
              "example"
            ],
            "properties": {
              "type": {
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            },
            "additionalProperties": true
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2
}

Can I trust it score from our own monitoring

score from our own monitoring

76/100 Solid

#113 of 129 in Verification. Bands: strong 93+, solid 75+, mixed 55+, weak below 55.

Reliability
100% uptime since 10-14
Compliance
unknown not evaluated
Price
$0.02 to $0.50 p64 in Verification
Risk
clean no risk flag
Traction
$0.00 30d 0 buyers
compliance checks
  • 402 payload captured
  • accepts[] array present
  • payTo address recoverable
  • payTo at accepts[0].payTo (conformant shape)
  • payTo is a valid on-chain address
  • atomic price declared
  • atomic price in a sane range
  • asset (token) address declared
  • network resolves to CAIP-2
  • payment scheme declared
  • served over HTTPS
  • declares the current x402 version (2)
  • EIP-712 domain parameters present on every EVM entry
  • x402 v2 envelope delivered in the payment-required header

402 terms unchanged since 2026-10-14. Last up 2026-10-14.

── Site signals

  • homepage reachable
  • openapi doc
  • pricing page
  • llms.txt
  • robots.txt
  • terms page
How the score works

What the score read on this service: status online, 100% uptime, latest daily rollup (no 30d window yet), 199ms average response (no p95 yet), no gradeable x402 checklist (scored on the payment-ready prior), $0.02 price against the category, on-chain traction measured. Each of those is measured, and each is published in full below.

The score comes from our own monitoring, never from reviews, operator claims, or a language model: reliability, x402 compliance, price against the category, a deterministic risk flag, and a small on-chain traction term, weighted by ranking generation 3. It is not placement anyone can buy: the paid verify tier is reported beside it and is not one of its inputs. Every component below stays published and read-only.

Bands on the 0 to 100 measured score: strong at 93 and above, solid from 75, mixed from 55, weak below 55. Price and speed are scored against the whole category field, every listing in it that carries no danger flag, the scored service included, so the score places a service in its own field.

It is a score inside Verification, and only there: price and speed are scored against the whole category field, every listing in it that carries no danger flag, the scored service included, which here means 129 listings, this one among them: the same 129 the position above is counted against. When the two differ, the field is the wider one, because a listing we have measured too little of to rank still sits in the field the price and the speed are normalized over. The same service in a different field would read differently. The same engine answers GET /api/v1/best, and asked for a different pool (the whole directory, or another filter) it returns a different number for this service under this same ranking generation. Neither is more correct: they answer different questions, and the methodology states which is which.

Traction is a conservative undercount.

All measured facts

What it does

FactStamp verifies a company against official public registers in 15 jurisdictions and returns a dated, cited, machine-readable answer. Paid per call over x402 (USDC on Base); free catalogue at /series.json.

FactStamp is a listed x402 Verification API. Captured payment terms name Base. Monitoring and settlement figures below describe the observations available to this directory; an unpaid HTTP 402 check does not prove that a paid call will deliver.

Assessment computed at . Latest service check observed at . Service data JSON · Measurement methodology.

Page rendered at . This response time is separate from the observation and computation times attached to each measurement.

Latest endpoint observation: . Latest price capture: . Prices are recorded quotes, not a promise of availability. Token assets and payment terms are listed separately. Endpoint data JSON · Price history JSON · Measurement methodology.

Assessment computed at . Uptime uses the stated daily-rollup window; response times are in milliseconds, compliance is passed/evaluated checks, and traction is a measured settlement floor. The comparison score is out of 100 within this category. Assessment JSON · Measurement methodology.

Observed daily coverage: 2026-09-15 to 2026-10-14 UTC. Daily monitoring and settlement rollups do not expose their computation time; a bucket date is not an update timestamp. Uptime and response JSON · Volume JSON · Buyers JSON · Measurement methodology.

Ranked from the measured category pool, refreshed at most once a minute. The comparison has no persisted computation timestamp; the assessment time above belongs to this service only. Ranking API documentation · Ranking methodology.

x402 List home · Services · Verification

uptime · latest daily rollup
-
uptime 7d
-
uptime 30d
-
uptime 90d
-
response p95
-
avg response
-
total checks
0

Measured on the unpaid 402 handshake, not the paid call. A service can 402 correctly and still fail after payment.

price (min)
$0.02
price (max)
$0.50
category percentile (min)
p64 in Verification
category percentile (max)
p75 in Verification
endpoints / prices
10 / 7
model
tiered
stability
100%

No deterministic risk flag. Risk fires only on an exact blocklist match, or a reserved-brand name with a mismatched verified payTo. Never from low uptime, a high price, or a model guess.

domain age
4d
registrar
CloudFlare, Inc.
hosting
custom
domain created
2026-10-10

Identity facts, not a risk score.

assessment volume 30d
$0.00
exact assessment volume 30d (USD)
0
assessment recorded at (UTC)
2026-10-14T10:03:04.542Z
buyers 30d
0
settlements 30d
0
measured since
--- (start of our harvest window)
last settlement
---
top buyer share
-
top 3 buyers share
-
concentrated volume
no
trend 7d vs 30d
-
networks
eip155:8453
volume all-time
$0
settlements all-time
0
median settlement 30d
-
max settlement 30d
-

Assessment volume uses the latest 30d assessment. Over time sums daily address snapshots, rounded to cents and refreshed separately. The two sources can differ in timing, precision and shared-address attribution. Amounts use cents for comparison; known sub-cent values keep up to 12 significant digits. The exact stored assessment value is shown above.

Conservative undercount: only USDC settlements via facilitators we measure are counted. A measured floor, not an estimate.

Top buyer share lowers the on-chain traction part of the ranking score behind this page's verdict and /best, by up to half when one address holds all 30d volume. The Recommended and Highest volume sorts of the services list do not use it; they use the Concentrated volume rule instead.

member since
2026-10-14
Recent checks
Latest 7 unpaid HTTP checks, newest first; response times in milliseconds, observation times in UTC
Checked at (UTC)StatusHTTPResponseEndpoints
Online402149ms10
Online402194ms10
Online402254ms10
Online402163ms10
Online402176ms10
Online402209ms10
Online402246ms10

Changes0 in 30d

No changes recorded in the last 30 days.

all changes

Over time

On-chain volume daily snapshots, USD 30d: $0.00, peak $6.01 on 10-05
volume no data in the payload
Distinct buyers per dayDistinct buyers per day
Uptime no completed-day data
Volume 30d
$0.00
Uptime
no completed-day data
Daily on-chain settlement volume in US dollars, 2026-09-15 to 2026-10-14; highest day $6.01 on 10-05; 4 days have no data in the payload; distinct buyers per day
More charts
Response time daily average, ms min 198ms, avg 198ms, max 198ms

09-15 to 10-14* UTC

Each series spans only the dates it has data for. Every series is also served as JSON at /api/v1/services/factstamp/price, /scores, /volume and /buyers.

Values

* today so far, partial (UTC).

The uptime summary counts completed UTC days only. The strip, readouts and table retain today's partial reading.

Daily snapshot total, 30d: $7.41, peak $6.01 on 10-05. The visible 30d total in Traction comes from the latest assessment. These sources can differ in their window, refresh time, cent rounding and shared-address attribution.

Daily address snapshots: 2026-09-15 to 2026-10-14 UTC; * today so far, partial (UTC). Daily snapshots store cents. A recorded $0.00 with settlements cannot distinguish exact zero from volume rounded away. Lost precision is unavailable here.

Settlement volume uses the stored USD valuation of tracked payments; it is distinct from token quantities. USD-pegged assets are valued at 1 USD per token in these rollups. The measured settlement floor does not cover all payments to this service.

Assessment history last recorded at . Each UTC day uses its last recorded run; missing readings stay unmeasured. Assessment history JSON · Measurement methodology.

Daily values, 2026-10-05 to 2026-10-14: address settlement volume in USD, distinct buyer and settlement counts, uptime percent, average response milliseconds, compliance passed/total, price percentile 0-100, site signals out of 6; UTC dates
DayVolumeBuyersSettlementsUptimeResponseCompliancePrice percentileSite signals
2026-10-05$6.0118no datano datano datano datano data
2026-10-06$0.0722no datano datano datano datano data
2026-10-07$0.6124no datano datano datano datano data
2026-10-08no datano datano datano datano datano datano datano data
2026-10-09$0.5215no datano datano datano datano data
2026-10-10$0.1011no datano datano datano datano data
2026-10-11no datano datano datano datano datano datano datano data
2026-10-12no datano datano datano datano datano datano datano data
2026-10-13$0.1011no datano datano datano datano data
2026-10-14*no datano datano data100%198.50msno datap645/6

Alternatives in Verification

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Rubric Protocol · Post-Quantum AI Attestation solid 93/100 99.8% up 30d $30.97 30d
Rooms by Aurmada paid tools solid 89/100 --- up 30d $0 30d
767-2676.com - POPCORN solid 89/100 100% up 30d $0.17 30d
KushBitx AgentProof solid 89/100 100% up 30d $1.52 30d

5 of 128 other ranked services in Verification, ordered by the same measured score.

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