C4 Architecture Guide

What it does

This skill enables AI agents to generate and visualize C4 (Context, Container, Component, and Code) diagrams for software systems. It translates complex codebases into structured visual representations that clarify system architecture at different levels of abstraction.

When to use it

• Onboard new developers by creating high-level Context diagrams to explain how your system fits within the broader ecosystem.
• Document microservices architectures using Container diagrams to illustrate interactions between services and external dependencies.
• Refactor legacy codebases by generating Component diagrams to map out internal logic and data flow without getting lost in implementation details.
• Prepare for technical interviews or stakeholder reviews by producing clear, standardized visual summaries of your application's structure.

Key capabilities

• Generates C4 diagrams across all four levels: Context, Container, Component, and Code.
• Automatically infers relationships between system components based on code analysis.
• Produces both static documentation and interactive diagram formats suitable for modern tech stacks.
• Supports multiple output formats including PlantUML, Mermaid, and standard image exports.

Example prompts

• "Analyze this React application and generate a C4 Container diagram showing how the frontend communicates with the backend API."
• "Create a C4 Component diagram for the authentication module in this Node.js service to highlight key classes and their interactions."
• "Produce a high-level C4 Context diagram explaining how our e-commerce platform integrates with third-party payment gateways and inventory systems."

Tips & gotchas

Ensure your codebase includes sufficient comments or documentation, as the skill relies on these to accurately infer architectural relationships. For large monolithic applications, consider breaking the analysis into smaller sub-systems to maintain diagram clarity and avoid overwhelming visual complexity.