WebhookPayload

{
    "event": "payment.completed",
    "payment_id": "01HXYZ123ABC456DEF789GHI",
    "merchant_reference": "order_12345",
    "merchant_meta": {
        "customer_id": "cust_789",
        "order_type": "retail"
    },
    "status": "completed",
    "amount": 5000,
    "currency": "USD",
    "authorization_code": "AUTH123456",
    "created_at": 1699564800000,
    "completed_at": 1699564802000
}