Cqrs Implementation

by wshobson46891e7e60daNo licenseListed Oct 8, 2026Updated Oct 8, 2026

Implement Command Query Responsibility Segregation for scalable architectures. Use when separating read and write models, optimizing query performance, or building event-sourced systems.

Instructions onlySoftware Development

AI-generated overview

Guides implementing CQRS by separating command and query models, with templates in a reference file.

What it does: This skill provides guidance for implementing Command Query Responsibility Segregation (CQRS) architectures. It explains core concepts such as commands, command handlers, events, queries, query handlers, and projectors, and lists best practices and pitfalls. It points to a reference file containing a template library and detailed worked examples.
When to use it: Use it when separating read and write models, scaling reads independently from writes, building event-sourced systems, or optimizing complex query and reporting scenarios. It is intended for design and implementation guidance rather than producing code artifacts directly.
Requirements: No scripts or tools are required; it is instructions only. Reading the bundled reference file references/details.md is suggested for concrete templates.

CQRS Implementation

Comprehensive guide to implementing CQRS (Command Query Responsibility Segregation) patterns.

When to Use This Skill

Separating read and write concerns
Scaling reads independently from writes
Building event-sourced systems
Optimizing complex query scenarios
Different read/write data models needed
High-performance reporting requirements

Core Concepts

1. CQRS Architecture

                    ┌─────────────┐                    │   Client    │                    └──────┬──────┘                           │              ┌────────────┴────────────┐              │                         │              ▼                         ▼       ┌─────────────┐          ┌─────────────┐       │  Commands   │          │   Queries   │       │    API      │          │    API      │       └──────┬──────┘          └──────┬──────┘              │                         │              ▼                         ▼       ┌─────────────┐          ┌─────────────┐       │  Command    │          │   Query     │       │  Handlers   │          │  Handlers   │       └──────┬──────┘          └──────┬──────┘              │                         │              ▼                         ▼       ┌─────────────┐          ┌─────────────┐       │   Write     │─────────►│    Read     │       │   Model     │  Events  │   Model     │       └─────────────┘          └─────────────┘

                    ┌─────────────┐                    │   Client    │                    └──────┬──────┘                           │              ┌────────────┴────────────┐              │                         │              ▼                         ▼       ┌─────────────┐          ┌─────────────┐       │  Commands   │          │   Queries   │       │    API      │          │    API      │       └──────┬──────┘          └──────┬──────┘              │                         │              ▼                         ▼       ┌─────────────┐          ┌─────────────┐       │  Command    │          │   Query     │       │  Handlers   │          │  Handlers   │       └──────┬──────┘          └──────┬──────┘              │                         │              ▼                         ▼       ┌─────────────┐          ┌─────────────┐       │   Write     │─────────►│    Read     │       │   Model     │  Events  │   Model     │       └─────────────┘          └─────────────┘

2. Key Components

Component	Responsibility
Command	Intent to change state
Command Handler	Validates and executes commands
Event	Record of state change
Query	Request for data
Query Handler	Retrieves data from read model
Projector	Updates read model from events

Templates and detailed worked examples

Full template library and detailed worked examples live in references/details.md. Read that file when you need the concrete templates.

Best Practices

Do's

Separate command and query models - Different needs
Use eventual consistency - Accept propagation delay
Validate in command handlers - Before state change
Denormalize read models - Optimize for queries
Version your events - For schema evolution

Don'ts

Don't query in commands - Use only for writes
Don't couple read/write schemas - Independent evolution
Don't over-engineer - Start simple
Don't ignore consistency SLAs - Define acceptable lag

Source and attribution

Source:wshobson/agentsinplugins/backend-development/skills/cqrs-implementationat commit46891e7

License: No license

Content belongs to its original authors. SourceWeft indexes it from a public repository.

Report or request removal

Cqrs Implementation

CQRS Implementation

When to Use This Skill

Core Concepts

1. CQRS Architecture

2. Key Components

Templates and detailed worked examples

Best Practices

Do's

Don'ts

Source and attribution

More from wshobson/agents

Workflow Orchestration Patterns

Temporal Python Testing

Projection Patterns

Microservices Patterns

Event Store Design

Task Coordination Strategies

More in Software Development

Playground

M5 Onboard

Cardputer Buddy

Dev

Dpop Adoption

Web Design Guidelines