diagram-gen

Diagram Generator

Architecture diagrams are always out of date because nobody maintains them. This tool reads your code and generates accurate Mermaid diagrams automatically.

One command. Zero config. Just works.

Quick Start

npx ai-diagram ./src/

What It Does

• Generates Mermaid diagrams from your code
• Supports flowcharts, class diagrams, sequence diagrams
• Creates ER diagrams from database schemas
• Outputs markdown-compatible Mermaid syntax

Usage Examples

# Generate flowchart
npx ai-diagram ./src/

# Class diagram
npx ai-diagram ./src/ --type class -o architecture.mmd

# Sequence diagram of function calls
npx ai-diagram ./src/ --type sequence

# Entity relationship diagram
npx ai-diagram ./src/ --type er

Best Practices

• Pick the right diagram type - use class for OOP, flow for processes
• Focus on key modules - don't diagram everything
• Keep them updated - run periodically as code changes
• Add to docs - Mermaid renders in GitHub markdown

When to Use This

• Onboarding new team members
• Documentation that's always out of date
• Understanding unfamiliar codebases
• Architecture reviews and planning

Part of the LXGIC Dev Toolkit

This is one of 110+ free developer tools built by LXGIC Studios. No paywalls, no sign-ups, no API keys on free tiers. Just tools that work.

Find more:

• GitHub: https://github.com/LXGIC-Studios
• Twitter: https://x.com/lxgicstudios
• Substack: https://lxgicstudios.substack.com
• Website: https://lxgicstudios.com

Requirements

No install needed. Just run with npx. Node.js 18+ recommended. Needs OPENAI_API_KEY environment variable.

npx ai-diagram --help

How It Works

Reads your source files to understand the structure, relationships, and data flow. Then generates Mermaid syntax that renders as diagrams in markdown editors, GitHub, and documentation tools.

License

MIT. Free forever. Use it however you want.