Glossary
Webhook reliability (retries, signatures, replay)
Patterns for production-grade webhooks
Scell.io webhooks retry with exponential backoff (5 attempts over 24h), are HMAC-SHA256-signed, timestamped (anti-replay), and complemented by a logs endpoint `GET /api/v1/webhooks/{id}/logs`. Receiver side: validate signature, deduplicate on event_id, reply 2xx within 5s.