Card snapshot

This is a frozen copy of the agent's agent-card.json as we observed it at the timestamp above. We capture a new snapshot every time the card's content hash changes. Useful for: forensic drift analysis, verifying downstream callers see the right version, reproducing routing decisions made historically.

{
  "protocolVersion": "0.3.0",
  "name": "FactStamp",
  "description": "Paid verification for agents: cited, dated answers about a company, a figure or a citation, each with an Ed25519 receipt that verifies offline.",
  "url": "https://agents.factstamp.dev/mcp",
  "preferredTransport": "MCP (streamable HTTP)",
  "version": "0.1.3",
  "provider": {
    "organization": "Alpine AI",
    "url": "https://agents.factstamp.dev"
  },
  "documentationUrl": "https://agents.factstamp.dev/docs",
  "transports": {
    "mcp": {
      "url": "https://agents.factstamp.dev/mcp",
      "type": "streamable-http"
    },
    "a2a": null
  },
  "a2a_endpoint": null,
  "capabilities": {
    "streaming": false,
    "pushNotifications": false
  },
  "defaultInputModes": [
    "application/json"
  ],
  "defaultOutputModes": [
    "application/json"
  ],
  "securitySchemes": {
    "x402": {
      "type": "http",
      "scheme": "x402",
      "description": "Pay per call in USDC on Base (eip155:8453). An unpaid call returns HTTP 402 with the challenge; the manifest is at https://agents.factstamp.dev/.well-known/x402."
    },
    "pack_code": {
      "type": "http",
      "scheme": "bearer",
      "description": "A prepaid pack bought by card at https://agents.factstamp.dev/packs; present the code as `authorization: Bearer ***`. A pack can also be bought with PayPal: POST https://agents.factstamp.dev/packs/paypal/checkout returns a buyer approval link and an order id, the buyer approves it on their own device, and the code is then read once at GET https://agents.factstamp.dev/packs/claim?session_id=\u2026 (poll first with &peek=1)."
    }
  },
  "skills": [
    {
      "id": "check_entity",
      "name": "check_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.",
      "url": "https://agents.factstamp.dev/entity",
      "method": "POST",
      "inputModes": [
        "application/json"
      ],
      "outputModes": [
        "application/json"
      ],
      "price_usd": 0.1,
      "payment": "x402"
    },
    {
      "id": "check_entity_file",
      "name": "check_entity_file",
      "description": "When 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 five lists, and the ownership chain to the ultimate parent \u2014 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.",
      "url": "https://agents.factstamp.dev/entity-file",
      "method": "POST",
      "inputModes": [
        "application/json"
      ],
      "outputModes": [
        "application/json"
      ],
      "price_usd": 0.438119,
      "payment": "x402"
    },
    {
      "id": "check_figure",
      "name": "check_figure",
      "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.",
      "url": "https://agents.factstamp.dev/check",
      "method": "POST",
      "inputModes": [
        "application/json"
      ],
      "outputModes": [
        "application/json"
      ],
      "price_usd": 0.05,
      "payment": "x402"
    },
    {
      "id": "verify_citation",
      "name": "verify_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.",
      "url": "https://agents.factstamp.dev/citation",
      "method": "POST",
      "inputModes": [
        "application/json"
      ],
      "outputModes": [
        "application/json"
      ],
      "price_usd": 0.02,
      "payment": "x402"
    },
    {
      "id": "verify_package",
      "name": "verify_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.",
      "url": "https://agents.factstamp.dev/package",
      "method": "POST",
      "inputModes": [
        "application/json"
      ],
      "outputModes": [
        "application/json"
      ],
      "price_usd": 0.02,
      "payment": "x402"
    },
    {
      "id": "check_document",
      "name": "check_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.",
      "url": "https://agents.factstamp.dev/document",
      "method": "POST",
      "inputModes": [
        "application/json"
      ],
      "outputModes": [
        "application/json"
      ],
      "price_usd": 0.25,
      "payment": "x402"
    },
    {
      "id": "watch_add",
      "name": "watch_add",
      "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 \u2014 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).",
      "url": "https://agents.factstamp.dev/watch",
      "method": "POST",
      "inputModes": [
        "application/json"
      ],
      "outputModes": [
        "application/json"
      ],
      "price_usd": 0.5,
      "payment": "x402"
    },
    {
      "id": "watch_portfolio",
      "name": "watch_portfolio",
      "description": "Watch a whole list at once, when a bibliography or a dependency manifest has to stay true: up to 25 citations or package versions re-checked every day for 30 days under one token. US$5 a portfolio \u2014 20 cents a reference, under a cent a check. Every reference is answered and signed on purchase, and each real change gets its own signed receipt. Nothing is sent when nothing changed. A single subject on its own is /watch. Pay per call here, or redeem a prepaid pack code (100 credits).",
      "url": "https://agents.factstamp.dev/watch/portfolio",
      "method": "POST",
      "inputModes": [
        "application/json"
      ],
      "outputModes": [
        "application/json"
      ],
      "price_usd": 5,
      "payment": "x402"
    },
    {
      "id": "verify_bulk",
      "name": "verify_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 \u2014 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).",
      "url": "https://agents.factstamp.dev/bulk",
      "method": "POST",
      "inputModes": [
        "application/json"
      ],
      "outputModes": [
        "application/json"
      ],
      "price_usd": 0.12,
      "payment": "x402"
    }
  ],
  "receipts": {
    "alg": "Ed25519",
    "issuer_document": "https://agents.factstamp.dev/.well-known/factstamp-issuer.json",
    "key_set": true,
    "verify_offline": true
  },
  "note": "MCP and plain HTTP only: no A2A JSON-RPC endpoint is implemented on this host. The skills above are the paid HTTP doors, with their prices; the MCP tools with the same names are served at https://agents.factstamp.dev/mcp. Free surfaces: /llms.txt, /pricing.md, /openapi.json, /.well-known/x402."
}