What it does
Diagram Design is a "skill", an add-on that teaches AI coding assistants a new ability. Once installed, you can ask for something like "an architecture diagram of my app" or "a chart of projects by impact versus effort".
The assistant picks a diagram type from dozens of options and writes a single web-page file you can open by double-clicking. It can copy the colours and fonts from your website so diagrams match your brand.
It works with many assistants, including Claude Code, Codex, GitHub Copilot and Cursor, and can import diagrams from tools like draw.io, Mermaid or Excalidraw.
Who it's for
People who already use an AI coding assistant and want good-looking diagrams for docs or presentations.
Can I use it without coding?
With some setup. Installed with one command into an AI coding tool; after that you just ask in plain words. New to this? Start here.
Can I run it?
- Cost
- Free, but needs an AI accountThe software is free, but it uses an online AI service (like OpenAI or Anthropic), which usually charges for use.
- Computer
- An ordinary computer is fine
- API key
- Not needed
Try it
- Use an AI assistant that supports Agent Skills, such as Claude Code, Cursor or Codex.
- Install the diagram-design skill into that assistant.
Using Claude Code, Cursor or another AI coding assistant? Paste the prompt and it will walk you through the setup.New to this?
Before you install
- Only download from the official GitHub page. Copies with similar names exist for many popular projects.
- License (MIT): Very permissive: free to use, change and share, including for business.
- More on staying safe