Diagram Design Installation Requirements: Complete Setup Guide for 2024

You need a supported AI assistant platform (Claude Code, Codex, Factory Droid, or Pi), network access to GitHub, and optionally Python 3 with Playwright for PNG export capabilities.

Diagram Design is an open-source plugin distributed through multiple AI-assistant marketplaces. Whether you're adding diagram generation to your Claude Code workflow or integrating with Codex, this guide covers every installation requirement based on the cathrynlavery/diagram-design source code.

Supported Agent Platforms

Diagram Design installs as a skill plugin rather than a standalone application. Each platform uses its own marketplace CLI:

• Claude Code – uses /plugin commands
• Codex – uses codex plugin commands
• Factory Droid – uses droid plugin commands
• Pi – uses pi install commands

The README.md file contains platform-specific instructions for each marketplace. No single universal installer exists—you must use the CLI native to your assistant.

Standard Installation by Platform

Claude Code

/plugin marketplace add cathrynlavery/diagram-design
/plugin install diagram-design@diagram-design

Codex

codex plugin marketplace add cathrynlavery/diagram-design
codex plugin add diagram-design@diagram-design

Factory Droid

droid plugin marketplace add https://github.com/cathrynlavery/diagram-design
droid plugin install diagram-design@diagram-design --scope user

Pi

pi install https://github.com/cathrynlavery/diagram-design

These commands contact the public GitHub marketplace to fetch the plugin. No private repository access is required for standard installation.

Network and Access Requirements

• Internet connectivity – All installation commands pull from https://github.com/cathrynlavery/diagram-design
• GitHub reachability – The marketplace endpoints must be accessible from your environment
• No VPN/proxy exceptions – Unless your organization mirrors the marketplace (see below)

Per the README.md "Claude Cowork" section, organizations can host mirrored copies in private marketplaces. This requires additional repository configuration but is optional for most users.

Optional: Editable/Local Development Install

To customize style guides or modify skill sources, clone the repository and install from local checkout:

git clone git@github.com:cathrynlavery/diagram-design.git ~/code/diagram-design

Then install via your platform's local path command:

Pi:

pi install ~/code/diagram-design

Claude Code:

ln -s ~/code/diagram-design/skills/diagram-design ~/.claude/skills/diagram-design

This requires:

• Git – for cloning the repository
• Local filesystem access – to the skills/diagram-design/ directory containing core plugin sources

After local installation, use scripts/lint-skin.py and scripts/self_check.py to validate your customization.

PNG Export Requirements

Diagram Design generates SVG diagrams by default. For PNG raster export, you need additional dependencies:

pip install playwright && playwright install chromium

Python 3 is required, and Playwright handles HTML-to-image rendering. Install this once before your first PNG export—it is not needed for standard diagram generation or SVG output.

The README.md "Export to PNG / SVG" section documents this prerequisite explicitly. No other Python dependencies are mandatory for core functionality.

Key Files Controlling Installation

File	Purpose
README.md	Primary installation guide with platform commands
skills/diagram-design/	Core plugin source installed by marketplace commands
commands/install-diagram-design.md	Generated CLI reference from README
scripts/lint-skin.py	Style validation for customized installs
scripts/self_check.py	Post-installation verification

Summary

• Mandatory: Claude Code, Codex, Factory Droid, or Pi platform access
• Mandatory: Network connectivity to GitHub marketplace
• Optional: Git + local clone for editable development install
• Optional: Python 3 + Playwright + Chromium for PNG export only
• Source location: cathrynlavery/diagram-design repository
• Entry point: skills/diagram-design/ directory

Frequently Asked Questions

Does Diagram Design work without an AI assistant platform?

No. Diagram Design is architected as a skill plugin, not a standalone tool. It requires Claude Code, Codex, Factory Droid, or Pi to function. The README.md does not document headless or API-only usage.

Can I install Diagram Design offline or in an air-gapped environment?

Standard installation requires internet access to GitHub. However, the README.md "Claude Cowork" section describes organization marketplace mirroring—clone the repository internally and point your platform's marketplace to the mirrored copy. Local editable install also works fully offline after initial clone.

Is Playwright required for all Diagram Design features?

No. Playwright is only for PNG export. SVG generation, diagram editing, and all core features work without Python or Playwright installed. Add the dependency only if your workflow requires raster image output.

What permissions does the Factory Droid --scope user flag provide?

The --scope user flag installs Diagram Design for your user account only, rather than system-wide. This matches the repository's recommended installation pattern and avoids requiring elevated privileges in the droid plugin install command.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}