{
  "specVersion": "0.4",
  "type": "subscription.verification",
  "timestamp": "2026-10-27T13:00:00Z",
  "data": {
    "subscriptionId": "sub_Vq8nR3kX0bT5wLz2Hc7Ym4Pd",
    "challenge": "c9Xk2LmQ7vR0tB4nZp8WyF3s"
  }
}