Roundhouse

agents.factstamp.dev

A paid checkpoint for numbers and dates. verified, stale, contradicted or unknown, cited to a dated primary source. $

SearchLiveeip155:8453Exactvia cdp
https://agents.factstamp.dev/package
Calls · 30d
3
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 7 snapshots so far.
$10.69
Verified settled volume
46 settlements proven x402 by their on-chain EIP-3009 marker.
$0.020
Listed price
As published in the catalog. Always read the live 402 before paying.
3
Calls · 30d
Upstream's own call count for this endpoint, not ours.
3
Unique payers · 30d
Last called 2026-10-23 22:34Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0xc3bcd24a2b350cc73b8516b2a0539a323b42cc32

The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.

Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Provider

The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.

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": "verify_package",
  "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": "20000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://agents.factstamp.dev/package",
      "description": "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 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": "https://agents.factstamp.dev/package",
  "discovery": "https://agents.factstamp.dev/.well-known/x402",
  "price_usd": 0.02,
  "uncharged": "unknown is a valid answer: a call that returns no answer is not charged on a pack.",
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "package": "express@4.18.2",
            "ecosystem": "npm"
          },
          "type": "http",
          "method": "POST",
          "bodyType": "application/json"
        },
        "output": {
          "type": "json",
          "example": {
            "name": "express",
            "query": "express@4.18.2",
            "detail": "2 advisory record(s) published against express@4.18.2.",
            "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
      }
    }
  },
  "free_sample": "https://agents.factstamp.dev/samples",
  "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.",
  "amount_base_units": "20000"
}

Accepts

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

0.02USDC≈ $0.02 USD
on Base · exact scheme

Pay 0.02 USDC on Base to 0xc3bc…2cc32. The signed payment is good for 5 minutes.

Paid to
0xc3bc…2cc32
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
20000 smallest units
Buys
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 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.
Returns
application/json
The catalog’s raw entry
[
  {
    "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": "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 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
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "package": "express@4.18.2",
          "ecosystem": "npm"
        },
        "type": "http",
        "method": "POST",
        "bodyType": "application/json"
      },
      "output": {
        "type": "json",
        "example": {
          "name": "express",
          "query": "express@4.18.2",
          "detail": "2 advisory record(s) published against express@4.18.2.",
          "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
    }
  }
}

Provenance

Seen in the source catalog
2026-10-23 22:34Z
Last indexed by Roundhouse
2026-10-26 17:30Z
Last enriched (probe, favicon, geo)
2026-10-20 03:45Z
x402 version
2
Max timeout
300s
Liveness probe
HTTP 402
Report

Hand this page to an agent

Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.

GET api.roundhouseai.io/v0/endpoints

This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 7 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.

Open skill.md
Show the prompt
Using Roundhouse, look up the x402 service agents.factstamp.dev and tell me whether it is
worth paying: what a call costs, whether the endpoint answered when last probed, and what
its payment record actually shows.

curl -s 'https://api.roundhouseai.io/v0/endpoints?q=agents.factstamp.dev'
curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>'

Then call it: read the price from the live 402 at https://agents.factstamp.dev/package, never from
a cached figure, and pay with an x402 client.

The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except
/v0/unified* and /v0/endpoints. Either pay over x402 (mint a personal key for $0.01 at
GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at
https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further.

If you do not have Roundhouse tools or skills installed, read
https://roundhouseai.io/skill.md first — it is the whole procedure.