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sendcheck

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DataLiveeip155:8453Exactvia cdp
https://sendcheck-x402.pennyforgeorg.workers.dev/check
EvmCryptoSecurityUsdcAddress-verification
Calls · 30d
3↑ 24%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 16 snapshots so far.
$0.50
Verified settled volume
43 settlements proven x402 by their on-chain EIP-3009 marker.
$0.010
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.
2
Unique payers · 30d
Last called 2026-09-14 19:52Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x9504A5939AB5be2B2B1F8beA7D7ebeCcd96c485D

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.

Accepts

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

0.01USDC≈ $0.01 USD
on Base · exact scheme

Pay 0.01 USDC on Base to 0x9504…c485D. The signed payment is good for 1 minute.

Paid to
0x9504…c485D
USD Coin contract
0x8335…02913
Payment window
1 minute
As published
10000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x9504A5939AB5be2B2B1F8beA7D7ebeCcd96c485D",
    "amount": "10000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 60
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "chain": "base",
          "address": "0x9504A5939AB5be2B2B1F8beA7D7ebeCcd96c485D"
        },
        "type": "http",
        "method": "POST",
        "bodyType": "json"
      },
      "output": {
        "type": "json",
        "example": {
          "meta": {
            "ms": 912,
            "service": "sendcheck",
            "version": "1.8.1"
          },
          "chain": {
            "name": "Base",
            "usdc": "30.23",
            "usdt": "0.00",
            "block": 50804109,
            "chain": 8453,
            "native": "0.0026",
            "reachable": true,
            "usdcUnits": "30230079",
            "usdtUnits": "0",
            "isContract": false,
            "outgoingTxs": 3
          },
          "report": "SendCheck pre-send verification …",
          "address": "0x9504A5939AB5be2B2B1F8beA7D7ebeCcd96c485D",
          "verdict": {
            "gas": "0.00000039 ETH",
            "next": "Verify the recipient out-of-band before sending.",
            "level": "caution",
            "reasons": [
              "…"
            ],
            "headline": "Live wallet with recent activity.",
            "tokenMismatch": null
          },
          "checksum": {
            "status": "valid",
            "message": "Valid EIP-55 checksum address."
          }
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "properties": {
            "body": {
              "type": "object",
              "required": [
                "address"
              ],
              "properties": {
                "chain": {
                  "enum": [
                    "base",
                    "ethereum",
                    "arbitrum",
                    "optimism",
                    "polygon"
                  ],
                  "type": "string",
                  "description": "Chain to scan (default: base)"
                },
                "address": {
                  "type": "string",
                  "description": "EVM address to verify, 0x + 40 hex characters. Free format pre-check: GET /validate?address=…"
                }
              }
            },
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "POST"
              ],
              "type": "string"
            },
            "bodyType": {
              "enum": [
                "json"
              ],
              "type": "string"
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    }
  },
  "x-sendcheck-attestation": {
    "jws": "eyJhbGciOiJFUzI1NiIsImtpZCI6InNlbmRjaGVjay0yMDI2LTA5In0.eyJhc3NldCI6IjB4ODMzNTg5ZkNENmVEYjZFMDhmNGM3QzMyRDRmNzFiNTRiZEEwMjkxMyIsImV4cCI6MTgyMDk0MTEwNSwiaWF0IjoxNzg5NDA1MTA1LCJuZXR3b3JrIjoiZWlwMTU1Ojg0NTMiLCJwYXlUbyI6IjB4OTUwNEE1OTM5QUI1YmUyQjJCMUY4YmVBN0Q3ZWJlQ2NkOTZjNDg1RCIsInJvdXRlcyI6W3sibWF4UHJpY2UiOiIwLjAxIiwicmVzb3VyY2UiOiIvY2hlY2sifSx7Im1heFByaWNlIjoiMC4wNSIsInJlc291cmNlIjoiL2RlZXAifV0sInNlcnZpY2UiOiJodHRwczovL2FwaS5wZW5ueWZvcmdlLm9yZyIsInYiOjF9.p_dvRobcbv9NtLwO32_-eOJyPsqy3Mk3dDGxPq_4kpPzP3X82InAJ3MWxxulcixywB9Nv4sFGN7YyZkscpTN4Q",
    "key": {
      "x": "byHMSJi37KTtQRTkxSj1dNRUppDNKCMqj_W7dfC45Us",
      "y": "mTV7jNFab5gU3P77chUHrdbnm3pegzrOjWdLXL3WRvs",
      "alg": "ES256",
      "crv": "P-256",
      "kid": "sendcheck-2026-09",
      "kty": "EC",
      "use": "sig"
    },
    "info": {
      "input": {
        "body": {
          "chain": "base",
          "address": "0x9504A5939AB5be2B2B1F8beA7D7ebeCcd96c485D"
        },
        "type": "http",
        "method": "POST",
        "bodyType": "json"
      },
      "output": {
        "type": "json",
        "example": {
          "jws": "<ES256 JWS compact: b64url(header).b64url(canonical-JSON payload).b64url(64-byte signature)>",
          "key": {
            "x": "<base64url P-256 X>",
            "y": "<base64url P-256 Y>",
            "crv": "P-256",
            "kid": "sendcheck-2026-09",
            "kty": "EC"
          }
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "properties": {
            "body": {
              "type": "object",
              "required": [
                "address"
              ],
              "properties": {
                "chain": {
                  "enum": [
                    "base",
                    "ethereum",
                    "arbitrum",
                    "optimism",
                    "polygon"
                  ],
                  "type": "string",
                  "description": "Chain to scan (default: base)"
                },
                "address": {
                  "type": "string",
                  "description": "EVM address to verify, 0x + 40 hex characters. Free format pre-check: GET /validate?address=…"
                }
              }
            },
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "POST"
              ],
              "type": "string"
            },
            "bodyType": {
              "enum": [
                "json"
              ],
              "type": "string"
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-09-14 19:52Z
Last indexed by Roundhouse
2026-09-24 07:20Z
Last enriched (probe, favicon, geo)
2026-09-22 01:45Z
x402 version
2
Max timeout
60s
Liveness probe
HTTP 405
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. 16 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 sendcheck 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=sendcheck'
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://sendcheck-x402.pennyforgeorg.workers.dev/check, 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://roundhouseai.io/dashboard/team.

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