Advanced

This section covers internals and production-grade operating patterns.

Topics

• Structure of a Message: command/subscription/stream message fields and semantics.
• Queues – internals & delivery tuning: lifecycle configuration, leases, retries, DLQs.
• Delivery semantics and reliability: at-most-once vs at-least-once and idempotency patterns.
• JavaScript Events: integrating framework events with native JS events.

When to read this section

• you debug cross-service routing and message metadata
• you define production delivery/retry expectations
• you need stronger observability and operational safety controls