Paddock pre-payment endpoint verification — one-time query

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x153AA87807D8f6deb65Bd53B137Cee7AD2dacCDb",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "250000",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "method": "GET",
        "queryParams": {
          "endpoint_url": "https://api.example.com/x402/search",
          "expect_network": "eip155:8453",
          "expect_price_usdc": 0.01
        },
        "type": "http"
      },
      "output": {
        "example": {
          "checked_at": "2026-08-26T18:20:09.000Z",
          "reason_codes": [
            "live_402_observed",
            "contract_mismatch_price"
          ],
          "route": false,
          "schema_version": "verify_before_pay/0.10",
          "summary": "Do not route: the live 402 contract does not match on price_usdc.",
          "tool": "verify_before_pay"
        },
        "type": "json"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "additionalProperties": false,
          "properties": {
            "method": {
              "enum": [
                "GET",
                "HEAD",
                "DELETE"
              ],
              "type": "string"
            },
            "queryParams": {
              "properties": {
                "endpoint_url": {
                  "type": "string"
                },
                "expect_asset": {
                  "type": "string"
                },
                "expect_network": {
                  "type": "string"
                },
                "expect_price_usdc": {
                  "minimum": 0,
                  "type": "number"
                },
                "expect_seller": {
                  "type": "string"
                },
                "pay_to": {
                  "type": "string"
                }
              },
              "type": "object"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method"
          ],
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {
              "type": "object"
            },
            "type": {
              "type": "string"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  }
}

curl "https://paddock.finance/api/paddock/mcp/verify-before-pay"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://paddock.finance/api/paddock/mcp/verify-before-pay");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

import httpx
res = httpx.get("https://paddock.finance/api/paddock/mcp/verify-before-pay")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header