Why is projection idempotency critical in Event Sourcing?

Projections must be idempotent so that if you need to replay events to rebuild a read model, the system doesn't create duplicate rows or inconsistent data.

Does this tool help with concurrency issues in event stores?

It specifically looks for the presence of optimistic locking and version checks during event appends to prevent concurrent writes from corrupting the event stream.

What does a CQRS alignment audit involve?

The audit checks if your code strictly separates write operations (commands) from read operations (queries) to prevent state corruption and improve system scalability.

Can this skill find side effects in my query handlers?

Yes, it scans Query Handlers for persistence methods like save, persist, or flush that indicate a query is incorrectly modifying the application state.

PHP CQRS & Event Sourcing Auditor

Name: PHP CQRS & Event Sourcing Auditor
Author: dykyi-roman

bydykyi-roman

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API開発

Audits PHP codebases for strict CQRS and Event Sourcing alignment to ensure architectural integrity and data consistency.

This skill provides a specialized architectural audit for PHP projects implementing Command Query Responsibility Segregation (CQRS) and Event Sourcing. It helps developers maintain a clean separation between write and read models, ensures projections are idempotent for safe event replays, and validates event store integrity through optimistic locking checks. By identifying common antipatterns—such as commands returning data, queries with side effects, or missing event metadata—it ensures your system remains robust, scalable, and fully aligned with domain-driven design principles.

主な機能

01Detects Command-Query Separation (CQS) violations in handlers

02Verifies optimistic locking implementation in event stores

0345 GitHub stars

04Validates event metadata including versions and timestamps

05Identifies non-idempotent projections to prevent data duplication

06Flags side effects and write operations within read-only queries

ユースケース

01Ensuring event replay safety before deploying new read-model projections

02Refactoring legacy monoliths into clean CQRS/ES architectures

03Automating architectural code reviews for PHP microservices

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add dykyi-roman/awesome-claude-code check-cqrs-alignment

For use in Claude.ai and ChatGPT

Download Skill