Delivery semantics describe how an exchange should be sent, acknowledged, prioritized, expired, and retried.
Definition
Delivery semantics define how an exchange declares sync or async behavior, priority, expiry, retry posture, and acknowledgment expectations.
Why it matters
Delivery semantics tell the receiver what kind of promise the sender is making. A synchronous request, an asynchronous task, a time-limited instruction, and a progress-reporting workflow need different handling even when the payload body looks similar.
Sync vs async
Whether the sender expects immediate completion or an exchange that can continue outside one request.
Acknowledgment
Whether receipt, acceptance, failure, or progress should be explicitly reported.
Expiry and priority
Whether the message remains valid and how urgent it is relative to other work.
Common fields
Common fields include delivery mode, priority, expiration, retry or idempotency notes, acknowledgment requirements, progress reporting, and failure reporting.
Failure modes
- Make timeout and expiry visible before the work starts.
- Keep retry behavior separate from duplicate acceptance.
- Record acknowledgments when a handoff crosses a team or system boundary.
- Use canonical UAIX records for UAI-1 field behavior.