Reliability model

An event starts as queued. A worker pops its ID with BRPOP, reads the payload from Postgres, and sends an HTTP POST.

• A network error changes the status to retrying and schedules the ID in the terusin:retry sorted set.
• Retry delay is 10 × 2^retry_count seconds.
• After MAX_RETRIES, the status becomes failed.
• A 2xx response becomes delivered and records an attempt.
• Admins can retry, acknowledge, or delete an event.

Delivery is at least once: receivers must be idempotent. Use the provider business event ID or a deduplication key at the target.