Check that a URL is live and its data is fresh before your agent acts on its contents

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x7a19cd388c7f69145fef09b960853e0a429b6f4a",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "20000",
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:137",
    "payTo": "0x7a19cd388c7f69145fef09b960853e0a429b6f4a",
    "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
    "amount": "20000",
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:42161",
    "payTo": "0x7a19cd388c7f69145fef09b960853e0a429b6f4a",
    "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
    "amount": "20000",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "url": "https://example.com/data.json"
        },
        "bodyType": "json",
        "method": "POST",
        "type": "http"
      },
      "output": {
        "example": {
          "attestation": {
            "confidence": 0.98,
            "result": {
              "changed": false,
              "content_sha256": "9f86d081884c7d65",
              "reachable": true,
              "status": 200
            },
            "subject": {
              "url": "https://example.com/data.json"
            },
            "type": "freshness_verification"
          },
          "signature": {
            "alg": "ES256",
            "jwks": "/.well-known/jwks.json"
          }
        },
        "type": "json"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "properties": {
            "body": {
              "properties": {
                "prior_hash": {
                  "description": "Optional prior SHA-256 hex to compare against",
                  "type": "string"
                },
                "url": {
                  "description": "Full URL including https://",
                  "type": "string"
                }
              },
              "required": [
                "url"
              ],
              "type": "object"
            },
            "bodyType": {
              "const": "json"
            },
            "method": {
              "enum": [
                "POST"
              ]
            },
            "type": {
              "const": "http"
            }
          },
          "required": [
            "type",
            "method"
          ],
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {
              "type": "object"
            },
            "type": {
              "type": "string"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  }
}

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

const res = await fetch("https://402oracle.com/verify/freshness");
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://402oracle.com/verify/freshness")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header