Roundhouse AI

B20 Permit Inspector

A pay-per-call API marketplace powered by x402 and Base Builder Codes. Every payment is attributed onchain via ERC-8021.

SearchLiveeip155:8453Exactvia cdp
https://402.com.tr/api/x402/b20-permit
B20Base-token-standardFreezeSeizeToken-safety
Calls · 30d
2↓ 39%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 30 snapshots so far.
$54.37
Verified settled volume
1,286 settlements proven x402 by their on-chain EIP-3009 marker.
$0.030
Listed price
As published in the catalog. Always read the live 402 before paying.
2
Calls · 30d
Upstream's own call count for this endpoint, not ours.
2
Unique payers · 30d
Last called 2026-09-19 15:57Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x973a31858f4d2125f48c880542da11a2796f12d6

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",
  "sample": {
    "data": {
      "isB20": true,
      "nonce": "0",
      "owner": "0x973A31858f4D2125f48C880542DA11a2796f12D6",
      "address": "0xb20000000000000000000186a08e781c38059eec",
      "checkedAt": "2026-09-19T15:57:10.751Z",
      "supportsPermit": true,
      "domainSeparator": "0xd4f8bd427e9fce6ac90676c1dbd0a5db5284c1397afa4e5e4a76925c5baac692"
    },
    "note": "Preview of a real response — a paid call returns the full report (all signals, details & recommendation)."
  },
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x973a31858f4d2125f48c880542da11a2796f12d6",
      "amount": "30000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://402.com.tr/api/x402/b20-permit",
    "tags": [
      "b20",
      "base-token-standard",
      "freeze",
      "seize",
      "token-safety",
      "stablecoin",
      "compliance",
      "permit",
      "base",
      "x402"
    ],
    "mimeType": "application/json",
    "description": "🆕 Every B20 has ERC-2612 permit built in — approve a spender by signature instead of a transaction. Reads exactly what an agent needs to build a valid permit: the token's DOMAIN_SEPARATOR, the owner's current nonce (so the signed payload can't be rejected/replayed), and the EIP-712 domain/type struct. Read-only — signs nothing.",
    "serviceName": "B20 Permit Inspector"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "pathParams": {},
          "queryParams": {
            "owner": "0x973a31858f4d2125f48c880542da11a2796f12d6",
            "address": "0xb20000000000000000000186a08e781c38059eec"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "isB20": true,
            "nonce": "0",
            "owner": "0x973A31858f4D2125f48C880542DA11a2796f12D6",
            "address": "0xb20000000000000000000186a08e781c38059eec",
            "checkedAt": "2026-09-19T15:57:10.751Z",
            "supportsPermit": true,
            "domainSeparator": "0xd4f8bd427e9fce6ac90676c1dbd0a5db5284c1397afa4e5e4a76925c5baac692"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET"
                ],
                "type": "string"
              },
              "pathParams": {
                "type": "object"
              },
              "queryParams": {
                "type": "object",
                "required": [
                  "address"
                ],
                "properties": {
                  "owner": {
                    "type": "string",
                    "description": "Owner wallet (for the nonce, optional)"
                  },
                  "address": {
                    "type": "string",
                    "description": "B20 token address"
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      },
      "routeTemplate": ":var1"
    },
    "builder-code": {
      "info": {
        "a": "bc_pa0gqlv1"
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "properties": {
          "a": {
            "type": "string",
            "pattern": "^[a-z0-9_]{1,32}$",
            "description": "App builder code"
          },
          "s": {
            "type": "array",
            "items": {
              "type": "string",
              "pattern": "^[a-z0-9_]{1,32}$"
            },
            "description": "Service builder codes"
          },
          "w": {
            "type": "string",
            "pattern": "^[a-z0-9_]{1,32}$",
            "description": "Wallet builder code"
          }
        },
        "additionalProperties": false
      }
    }
  },
  "x402Version": 2,
  "alternatives": [
    {
      "url": "https://402.com.tr/api/x402/buy-credits?tier=0.25",
      "then": "Send the returned token as the `x-credit-token` header on this and any paid call; each debits its price from the balance — no per-call signature.",
      "gives": "≈8 calls at this service's price from one settlement; lowest-friction start.",
      "action": "buy-credits",
      "method": "POST",
      "priceUsdc": "0.25",
      "recommended": true
    },
    {
      "url": "https://402.com.tr/api/x402/b20-permit",
      "gives": "Pay this exact call now over x402 — see the `accepts` array for scheme/amount/asset/payTo.",
      "action": "pay-x402",
      "method": "GET"
    }
  ],
  "prepaidCredits": "One x402 settlement on /api/x402/buy-credits?tier=0.25|1|5|20 mints a bearer credit token; send it as the x-credit-token header and later calls debit the balance — no wallet or signature per call after that first purchase."
}

Accepts

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

0.03USDC≈ $0.03 USD
on Base · exact scheme

Pay 0.03 USDC on Base to 0x973a…f12d6. The signed payment is good for 5 minutes.

Paid to
0x973a…f12d6
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
30000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x973a31858f4d2125f48c880542da11a2796f12d6",
    "amount": "30000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "pathParams": {},
        "queryParams": {
          "owner": "0x973a31858f4d2125f48c880542da11a2796f12d6",
          "address": "0xb20000000000000000000186a08e781c38059eec"
        }
      },
      "output": {
        "type": "json",
        "example": {
          "isB20": true,
          "nonce": "0",
          "owner": "0x973A31858f4D2125f48C880542DA11a2796f12D6",
          "address": "0xb20000000000000000000186a08e781c38059eec",
          "checkedAt": "2026-09-10T03:01:08.790Z",
          "supportsPermit": true,
          "domainSeparator": "0xd4f8bd427e9fce6ac90676c1dbd0a5db5284c1397afa4e5e4a76925c5baac692"
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method"
          ],
          "properties": {
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "GET"
              ],
              "type": "string"
            },
            "pathParams": {
              "type": "object"
            },
            "queryParams": {
              "type": "object",
              "required": [
                "address"
              ],
              "properties": {
                "owner": {
                  "type": "string",
                  "description": "Owner wallet (for the nonce, optional)"
                },
                "address": {
                  "type": "string",
                  "description": "B20 token address"
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    }
  },
  "builder-code": {
    "info": {
      "a": "bc_pa0gqlv1"
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "a": {
          "type": "string",
          "pattern": "^[a-z0-9_]{1,32}$",
          "description": "App builder code"
        },
        "s": {
          "type": "array",
          "items": {
            "type": "string",
            "pattern": "^[a-z0-9_]{1,32}$"
          },
          "description": "Service builder codes"
        },
        "w": {
          "type": "string",
          "pattern": "^[a-z0-9_]{1,32}$",
          "description": "Wallet builder code"
        }
      },
      "additionalProperties": false
    }
  }
}

Provenance

Seen in the source catalog
2026-09-19 15:57Z
Last indexed by Roundhouse
2026-09-24 14:10Z
Last enriched (probe, favicon, geo)
2026-09-22 08:45Z
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. 30 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 B20 Permit Inspector 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=B20%20Permit%20Inspector'
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://402.com.tr/api/x402/b20-permit, 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.