Backend Transactional Outbox

Purpose

Guarantee reliable event publication by writing events to an outbox table within the same database transaction as the business operation, then publishing them via a separate message relay process.

Agent Protocol

Trigger

Exact user phrases: "outbox", "transactional outbox", "outbox pattern", "reliable event publishing", "dual write", "CDC outbox", "message relay", "publish events", "exactly-once publish", "debezium outbox".

Input Context

• Database technology (PostgreSQL, MySQL, SQL Server, etc.).
• Message broker (Kafka, RabbitMQ, SQS, etc.).
• Whether dual-write (DB + broker) is a current problem.
• Current event publishing mechanism.

Output Artifact

Outbox implementation design as text. No file unless requested.