Paid Watchdog registration: 30 days of signed monitoring for one x402 endpoint

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xc87a06DEE4c0E85912296002617120BBfd5EF990",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "5000000",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "method": "GET",
        "queryParams": {
          "channel": "https://hooks.example.com/wd",
          "endpoint": "https://api.example-seller.com/x402/quote"
        },
        "type": "http"
      },
      "output": {
        "example": {
          "alert_types_enabled": [
            "endpoint_unreachable",
            "endpoint_recovered",
            "verdict_degraded",
            "verdict_restored",
            "payto_changed",
            "networks_changed",
            "asset_changed",
            "self_inconsistent_402_detected",
            "listing_disappeared_from_catalog"
          ],
          "channel_ref": "78e41ddd041f503681dc9aade1dfa0644953e4791c4dbd3027d311d5d930bb3c",
          "channel_type": "webhook",
          "digest": "ca96e3d0aaf1f883506aa90b2f3057289bd1b6141bed5b6966b2468024f24039",
          "endpoint": "https://api.example-seller.com/x402/quote",
          "expires_at": "2026-10-01T12:04:00+00:00",
          "limitations": [
            "monitoring begins at verified_at; changes before it are not covered; free tier is one endpoint per verified channel and cannot be swapped without a paid registration in v1"
          ],
          "manifest": {
            "entry": "watchdog",
            "url": "https://x402.nsgoods.org/proof/index.json"
          },
          "registered_at": "2026-09-01T12:00:00+00:00",
          "schema_version": "watchdog_v1",
          "signature": "0xf3c3c2980b877607fa85b5272e3b08cff9b37c711e297104ee1495a543f3189d42fec365153d6f9b912ae80308e4fd26803c92b6e10514ead21bf4147a5c3d811b",
          "signer": "0x57fF0F084Cba33e6761503f90eEF0Da9F159350c",
          "subscription_id": "sub_paid_demo",
          "tier": "paid",
          "type": "registration_receipt",
          "verification_status": "verified",
          "verified_at": "2026-09-01T12:04:00+00:00"
        },
        "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": {
                "channel": {
                  "description": "email address or https webhook URL for alerts.",
                  "type": "string"
                },
                "endpoint": {
                  "description": "https x402 endpoint URL to monitor.",
                  "type": "string"
                }
              },
              "required": [
                "endpoint",
                "channel"
              ],
              "type": "object"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method"
          ],
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {
              "properties": {
                "schema_version": {
                  "type": "string"
                },
                "signature": {
                  "type": "string"
                },
                "signer": {
                  "type": "string"
                },
                "tier": {
                  "type": "string"
                },
                "type": {
                  "type": "string"
                }
              },
              "required": [
                "schema_version",
                "type",
                "tier",
                "signer",
                "signature"
              ],
              "type": "object"
            },
            "type": {
              "type": "string"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  }
}

curl "https://x402.nsgoods.org/watchdog/register/paid"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://x402.nsgoods.org/watchdog/register/paid");
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://x402.nsgoods.org/watchdog/register/paid")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header