sequence-checking

What problem does it solve?

Ensures event handlers correctly handle duplicates and out-of-order events so message listeners can reliably complete or abandon messages without causing infinite retries or data corruption.

Core Features & Use Cases

• Inline guard pattern: A single in-handler check that returns true for already-processed events and false for gaps, avoiding external helper classes.
• Creation vs update handling: Creation handlers use existence checks while update handlers apply the sequence guard and then update the entity sequence.
• Use case: Add robust idempotency to microservice query handlers processing ordered aggregate events from a service bus.

Quick Start

Use the sequence-checking skill to add an inline guard comparing the entity sequence to the event sequence minus one, return true for duplicates and false for gaps, and ensure the entity behavior updates the sequence after processing.