C4 Model Skill

Purpose

This skill provides guidance on creating C4 (Context, Container, Component, Code) model diagrams using Mermaid syntax for architecture documentation. C4 models provide a hierarchical way to visualize software architecture at different levels of abstraction, following Simon Brown's C4 model methodology.

Rules

C4 Model Levels

The C4 model consists of four levels of abstraction:

1. Level 1: System Context - Shows how the system fits into its environment
2. Level 2: Container - Shows the high-level technology choices and communication between containers
3. Level 3: Component - Shows how containers are decomposed into components
4. Level 4: Code - Shows implementation details (optional, often better shown in IDEs)

When to Use Each Level