api.spendpreflight.com

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xBf4164e07552e4c1b1B1597E72C7acAA3F0a1c58",
      "amount": "50000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 60
    }
  ],
  "message": "Unpaid discovery only. Use the documented execution method and valid input to request a result. Existing query APIs accept signed GET or POST JSON; unsigned GET and every HEAD never execute, consume a trial or settle. Availability, authentication and input checks still apply before payment.",
  "request": {
    "body": {
      "url": "https://api.spendpreflight.com/v1/check",
      "method": "GET"
    },
    "method": "POST"
  },
  "resource": {
    "url": "https://api.spendpreflight.com/listing-guard",
    "mimeType": "application/json",
    "description": "Bazaar Listing Guard: CDP technical validation plus a bounded heuristic metadata screen for agent-directed instructions, embedded URLs, tool calls, invisible Unicode, long fields and prices above 100x a fresh Scout category median. Returns riskScore, flagged spans and rewrite suggestions. Not Coinbase policy certification or guaranteed detection. Public HTTPS only; no target payment or request bodies stored."
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "url": "https://api.spendpreflight.com/v1/check",
            "method": "GET"
          },
          "type": "http",
          "method": "POST",
          "bodyType": "json"
        }
      },
      "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": [
                  "url",
                  "method"
                ],
                "properties": {
                  "url": {
                    "type": "string",
                    "format": "uri",
                    "maxLength": 2048
                  },
                  "method": {
                    "enum": [
                      "GET",
                      "HEAD",
                      "POST"
                    ],
                    "type": "string"
                  }
                },
                "additionalProperties": false
              },
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "POST",
                  "PUT",
                  "PATCH"
                ],
                "type": "string"
              },
              "bodyType": {
                "enum": [
                  "json",
                  "form-data",
                  "text"
                ],
                "type": "string"
              }
            },
            "additionalProperties": false
          }
        }
      }
    }
  },
  "how_to_pay": "This is discovery only: use the documented GET query or POST JSON example with valid inputs, obtain its quote, then use your authorized payment client. HEAD never executes; unsigned GET never consumes a trial or settles. Use an authorized x402 v2 client to validate this quote, sign the exact selected requirement and retry the same request with PAYMENT-SIGNATURE. The PAYMENT-REQUIRED header and mirrored body carry the same quote. Do not send a separate USDC transfer.",
  "not_charged": true,
  "x402Version": 2,
  "payment_help": {
    "trial": "The shared UTC-day trial is limited. An exhausted trial requires an explicit payment decision; trial-only clients must stop, not silently fall back to paid access.",
    "example": {
      "code": "import { wrapFetchWithPayment } from '@x402/fetch';\n// paymentClient is your existing x402Client, configured with your authorized\n// wallet mechanism and a policy checking the quoted amount/asset/network/payTo.\nconst paidFetch = wrapFetchWithPayment(fetch, paymentClient);\n// Keep an unconsumed clone of the original request, including method/body.\nconst result = await paidFetch(originalRequest.clone());",
      "language": "JavaScript",
      "packages": [
        "@x402/fetch"
      ]
    },
    "versions": {
      "billing": "This service advertises v2 billing only. A v1-only payer must upgrade; renaming fields does not create a supported v1 payment.",
      "v1_reference": {
        "amount": "accepts[].maxAmountRequired",
        "network": "base",
        "resource": "accepts[].resource",
        "payment_header": "X-PAYMENT"
      },
      "v2_reference": {
        "amount": "accepts[].amount",
        "network": "eip155:8453",
        "resource": "resource.url",
        "payment_header": "PAYMENT-SIGNATURE"
      },
      "screening_input": "preflight_payment and /v1/preflight accept merchant challenges in x402 v1 or v2."
    },
    "amount_units": "Atomic token units; Base USDC has 6 decimals (10000 = 0.01 USDC). Use the exact amount in accepts, not the display price.",
    "retry_header": "PAYMENT-SIGNATURE",
    "retry_safety": "If a signed attempt times out or returns settlement_outcome_unknown, inspect that authorization/transaction before retrying. Never create another authorization automatically.",
    "billing_protocol": "x402 v2",
    "challenge_header": "PAYMENT-REQUIRED"
  },
  "discovery_only": true
}

Accepts

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

[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0xBf4164e07552e4c1b1B1597E72C7acAA3F0a1c58",
    "amount": "50000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 60
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "url": "https://api.spendpreflight.com/v1/check",
          "method": "GET"
        },
        "type": "http",
        "method": "POST",
        "bodyType": "json"
      }
    },
    "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": [
                "url",
                "method"
              ],
              "properties": {
                "url": {
                  "type": "string",
                  "format": "uri",
                  "maxLength": 2048
                },
                "method": {
                  "enum": [
                    "GET",
                    "HEAD",
                    "POST"
                  ],
                  "type": "string"
                }
              },
              "additionalProperties": false
            },
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "POST"
              ],
              "type": "string"
            },
            "bodyType": {
              "enum": [
                "json",
                "form-data",
                "text"
              ],
              "type": "string"
            }
          },
          "additionalProperties": false
        }
      }
    }
  }
}

Provenance

Seen in the source catalog

2026-10-22 22:07Z

Last indexed by Roundhouse

2026-10-26 19:30Z

Last enriched (probe, favicon, geo)

2026-10-22 23:16Z

x402 version

2

Max timeout

60s

Liveness probe

HTTP 402