Payments API

Appendix B - Webhook delivery

• Webhook retries: up to 5 attempts; backoff 10s, 60s, 5m, 15m (last attempt about 21 minutes after the first; see Webhooks).
• Each API client has its own webhook URL and secret. Rotate a secret under portal → Developers → API credentials; the new secret applies immediately to all deliveries (including pending retries) and there is no overlap window. Have your verifier accept both the old and new secret during the switch, then remove the old one.