# Cqrs Implementation

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

- **Type:** Skill
- **Install:** `agentstack add skill-wshobson-agents-cqrs-implementation`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [wshobson](https://agentstack.voostack.com/s/wshobson)
- **Installs:** 0
- **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [wshobson](https://github.com/wshobson)
- **Source:** https://github.com/wshobson/agents/tree/main/plugins/backend-development/skills/cqrs-implementation
- **Website:** https://sethhobson.com

## Install

```sh
agentstack add skill-wshobson-agents-cqrs-implementation
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# 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     │
       └─────────────┘          └─────────────┘
```

### 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 & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [wshobson](https://github.com/wshobson)
- **Source:** [wshobson/agents](https://github.com/wshobson/agents)
- **License:** MIT
- **Homepage:** https://sethhobson.com

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-wshobson-agents-cqrs-implementation
- Seller: https://agentstack.voostack.com/s/wshobson
- Browse the marketplace: https://agentstack.voostack.com/browse

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