Roundhouse

Groundcheck

Groundcheck verifies a factual claim against live sources and returns a verdict, a confidence score, and citations — over MCP, so any AI agent can call it mid-task.

InferenceLiveeip155:8453Exactvia cdp
https://groundcheck.seiche.info/extract
GroundingCitationsVerified-dataDelivery-receiptsAgentic-commerce
Calls · 30d
1
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 10 snapshots so far.
$0.24
Verified settled volume
12 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0050
Listed price
As published in the catalog. Always read the live 402 before paying.
1
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-08-16 22:29Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x5B4A78b7EFe482d1579E287dA6F0043f89cf0EA1

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.

{
  "error": "payment required (call with POST)",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x5B4A78b7EFe482d1579E287dA6F0043f89cf0EA1",
      "amount": "5000",
      "scheme": "exact",
      "network": "base",
      "mimeType": "application/json",
      "resource": "https://groundcheck.seiche.info/extract",
      "extensions": {
        "bazaar": {
          "info": {
            "input": {
              "body": {
                "text": "The Eiffel Tower was completed in 1889 and is 330 metres tall.",
                "max_claims": 20
              },
              "type": "http",
              "method": "POST",
              "bodyType": "json"
            },
            "output": {
              "type": "json",
              "example": {
                "count": 2,
                "claims": [
                  "The Eiffel Tower was completed in 1889",
                  "is 330 metres tall."
                ],
                "method": "sentence-heuristic + rule-based atom decomposition",
                "attestation": {
                  "receipt": {
                    "…": "…"
                  },
                  "attested": true
                },
                "input_sha256": "…64 hex…"
              }
            }
          },
          "schema": {
            "type": "object",
            "$schema": "https://json-schema.org/draft/2020-12/schema",
            "required": [
              "input"
            ],
            "properties": {
              "input": {
                "type": "object",
                "required": [
                  "type",
                  "method",
                  "body"
                ],
                "properties": {
                  "body": {
                    "type": "object",
                    "required": [
                      "text"
                    ],
                    "properties": {
                      "text": {
                        "type": "string",
                        "minLength": 1,
                        "description": "Text to split into independently checkable atomic factual claims"
                      },
                      "max_claims": {
                        "type": "integer",
                        "maximum": 50,
                        "minimum": 1
                      }
                    }
                  },
                  "type": {
                    "type": "string",
                    "const": "http"
                  },
                  "method": {
                    "type": "string",
                    "const": "POST"
                  },
                  "bodyType": {
                    "type": "string",
                    "const": "json"
                  }
                },
                "additionalProperties": false
              },
              "output": {
                "type": "object",
                "required": [
                  "type"
                ],
                "properties": {
                  "type": {
                    "type": "string",
                    "const": "json"
                  },
                  "example": {
                    "type": "object"
                  }
                }
              }
            }
          },
          "routeTemplate": "/extract"
        }
      },
      "description": "Claim extraction for agent verification loops: split text into independently checkable atomic factual claims via auditable rule-based decomposition (no LLM guessing), with a signed receipt bound to the input hash. The cheap first step of the loop — extract here, then ground what matters via /verify or /check.",
      "maxAmountRequired": "5000",
      "maxTimeoutSeconds": 60
    }
  ],
  "resource": {
    "url": "https://groundcheck.seiche.info/extract",
    "tags": [
      "grounding",
      "citations",
      "verified-data",
      "delivery-receipts",
      "agentic-commerce"
    ],
    "iconUrl": "https://groundcheck.seiche.info/favicon.ico",
    "mimeType": "application/json",
    "description": "Claim extraction for agent verification loops: split text into independently checkable atomic factual claims via auditable rule-based decomposition (no LLM guessing), with a signed receipt bound to the input hash. The cheap first step of the loop — extract here, then ground what matters via /verify or /check.",
    "serviceName": "Groundcheck"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "text": "The Eiffel Tower was completed in 1889 and is 330 metres tall.",
            "max_claims": 20
          },
          "type": "http",
          "method": "POST",
          "bodyType": "json"
        },
        "output": {
          "type": "json",
          "example": {
            "count": 2,
            "claims": [
              "The Eiffel Tower was completed in 1889",
              "is 330 metres tall."
            ],
            "method": "sentence-heuristic + rule-based atom decomposition",
            "attestation": {
              "receipt": {
                "…": "…"
              },
              "attested": true
            },
            "input_sha256": "…64 hex…"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method",
              "body"
            ],
            "properties": {
              "body": {
                "type": "object",
                "required": [
                  "text"
                ],
                "properties": {
                  "text": {
                    "type": "string",
                    "minLength": 1,
                    "description": "Text to split into independently checkable atomic factual claims"
                  },
                  "max_claims": {
                    "type": "integer",
                    "maximum": 50,
                    "minimum": 1
                  }
                }
              },
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "type": "string",
                "const": "POST"
              },
              "bodyType": {
                "type": "string",
                "const": "json"
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "json"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      },
      "routeTemplate": "/extract"
    }
  },
  "x402Version": 1
}

Accepts

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

0.005USDC≈ $0.005 USD
on Base · exact scheme

Pay 0.005 USDC on Base to 0x5B4A…f0EA1. The signed payment is good for 1 minute.

Paid to
0x5B4A…f0EA1
USD Coin contract
0x8335…02913
Payment window
1 minute
As published
5000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x5B4A78b7EFe482d1579E287dA6F0043f89cf0EA1",
    "amount": "5000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 60
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "text": "The Eiffel Tower was completed in 1889 and is 330 metres tall.",
          "max_claims": 20
        },
        "type": "http",
        "method": "POST",
        "bodyType": "json"
      },
      "output": {
        "type": "json",
        "example": {
          "count": 2,
          "claims": [
            "The Eiffel Tower was completed in 1889",
            "is 330 metres tall."
          ],
          "method": "sentence-heuristic + rule-based atom decomposition",
          "attestation": {
            "receipt": {
              "…": "…"
            },
            "attested": true
          },
          "input_sha256": "…64 hex…"
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method",
            "body"
          ],
          "properties": {
            "body": {
              "type": "object",
              "required": [
                "text"
              ],
              "properties": {
                "text": {
                  "type": "string",
                  "minLength": 1,
                  "description": "Text to split into independently checkable atomic factual claims"
                },
                "max_claims": {
                  "type": "integer",
                  "maximum": 50,
                  "minimum": 1
                }
              }
            },
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "type": "string",
              "const": "POST"
            },
            "bodyType": {
              "type": "string",
              "const": "json"
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string",
              "const": "json"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    },
    "routeTemplate": "/extract"
  }
}

Provenance

Seen in the source catalog
2026-08-16 22:29Z
Last indexed by Roundhouse
2026-09-04 19:00Z
Last enriched (probe, favicon, geo)
2026-09-01 19:15Z
x402 version
2
Max timeout
60s
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. 10 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 Groundcheck 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=Groundcheck'
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://groundcheck.seiche.info/extract, 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. Mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402,
or use an organization key from https://app.roundhouseai.io/dashboard/team.

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