agents.factstamp.dev

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "note": "Pay per call in USDC on Base, or redeem a prepaid pack and send it as a bearer token.",
  "tool": "check_document",
  "error": "This path answers a GET/HEAD probe with its price rather than a refusal: the terms below are the ones a POST is charged against, at this same resource. Send POST to buy.",
  "packs": "https://agents.factstamp.dev/packs",
  "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": "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, 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 included with the call. Verdicts: verified, stale, contradicted, unknown. Prose, not a list: a bare bibliography belongs to /bulk.",
      "maxAmountRequired": "250000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": "https://agents.factstamp.dev/document",
  "discovery": "https://agents.factstamp.dev/.well-known/x402",
  "price_usd": 0.25,
  "uncharged": "unknown is a valid answer: a call that returns no answer is not charged on a pack.",
  "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,
  "what_you_get": "Every answer is dated, names the publisher it cites, and carries a receipt that verifies offline without calling us again.",
  "sample_answers": "https://agents.factstamp.dev/samples",
  "zero_knowledge": {
    "why": "This door does not sell the zero knowledge option. Its settlement does not run through the gate that can blind a ledger entry, so offering it here would be a promise we could not keep.",
    "where": "https://agents.factstamp.dev/ledger/zero-knowledge",
    "option": "zero_knowledge",
    "sold_at": [
      "/check",
      "/entity-file",
      "/il/entity-file",
      "/ca/entity-file",
      "/sanctions",
      "/vat",
      "/citation",
      "/package",
      "/watch",
      "/watch/portfolio",
      "/bulk"
    ],
    "available": false
  },
  "amount_base_units": "250000"
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32",
    "scheme": "exact",
    "network": "eip155:8453",
    "mimeType": "application/json",
    "resource": "https://agents.factstamp.dev/document",
    "description": "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, as one signed bundle with a per-claim r…",
    "maxAmountRequired": "250000",
    "maxTimeoutSeconds": 300
  }
]

Provenance

Seen in the source catalog

2026-10-21 05:12Z

Last indexed by Roundhouse

2026-10-23 22:46Z

Last enriched (probe, favicon, geo)

2026-10-23 23:16Z

x402 version

1

Max timeout

300s

Liveness probe

HTTP 402