Verified against Semitexa Ultimate 2026.09.19.1020

Queued Handler

Queued listeners are serialized into a durable transport and processed by separate workers. The event payload leaves worker memory and enters the queue, so the work survives restarts and can scale horizontally.

How it works

When an event is dispatched with EventExecution::Queued, the dispatcher serializes the event and pushes it to the configured transport (NATS by default). A queue worker picks it up independently of the originating request or worker process.

Why this matters

Async deferred execution runs in the same worker and is lost on restart. Queued execution survives crashes, scales across worker pools, and supports retry and dead-letter queue (DLQ) semantics. Use queued listeners for any work that must not be lost: payment processing, third-party webhook calls, import jobs, and similar durable side effects.

Queue feature support

• Automatic retry on failure
• Dead-letter queue (DLQ)
• Cross-worker delivery
• Priority queues
• Survives worker restart