{
  "dateModified": "2026-06-02",
  "events": [
    "invoice.created",
    "invoice.paid",
    "invoice.overdue",
    "payment.received",
    "refund.issued",
    "dispute.opened",
    "dispute.resolved",
    "x402.settled"
  ],
  "signature": "HMAC-SHA384 + RFC 9421 HTTP Message Signatures",
  "retry": "exponential 5x over 24h",
  "endpoint": "configurable per agent"
}