From nickcrew-claude-ctx-plugin
Guides CQRS and Event Sourcing implementation for scalable, auditable systems with temporal queries, audit trails, and separated read/write models.
npx claudepluginhub nickcrew/claude-cortexThis skill uses the workspace's default tool permissions.
Expert guidance for implementing Command Query Responsibility Segregation (CQRS) and Event Sourcing patterns to build scalable, auditable systems with complete historical tracking and optimized read/write models.
Designs event-sourced systems using CQRS, event stores, projections, sagas, and eventual consistency patterns. Useful for audit trails, temporal queries, and complex workflows.
Designs event-sourced systems with CQRS, event stores, projections, sagas, and eventual consistency handling. For audit trails, temporal queries, complex workflows, and microservices.
Implements event sourcing and CQRS patterns using event stores, aggregates, and projections for audit trails, temporal queries, and full history systems.
Share bugs, ideas, or general feedback.
Expert guidance for implementing Command Query Responsibility Segregation (CQRS) and Event Sourcing patterns to build scalable, auditable systems with complete historical tracking and optimized read/write models.
Separate operations that change state (commands) from operations that read state (queries).
| Commands (Write) | Queries (Read) |
|---|---|
| Express intent (CreateOrder, UpdatePrice) | Return data, never change state |
| Can be rejected (validation failures) | Can be cached and optimized |
| Return success/failure, not data | Multiple models for different needs |
| Change system state | Eventually consistent with writes |
Store state changes as immutable events rather than current state snapshots.
Traditional: Store what IS → UPDATE users SET email = 'new@email.com'
Event Sourcing: Store what HAPPENED → APPEND UserEmailChanged event
Result: Complete history, temporal queries, audit trail
Accept temporary inconsistency between write and read models for scalability.
| Task | Load reference |
|---|---|
| CQRS implementation patterns | skills/cqrs-event-sourcing/references/cqrs-patterns.md |
| Event sourcing & snapshots | skills/cqrs-event-sourcing/references/event-sourcing.md |
| EventStoreDB & Axon Framework | skills/cqrs-event-sourcing/references/event-store-tech.md |
| Consistency patterns | skills/cqrs-event-sourcing/references/consistency-patterns.md |
| Best practices checklist | skills/cqrs-event-sourcing/references/best-practices.md |