How to Install Diagram Design: A Complete Guide for Claude Code, Codex, Factory Droid, and Pi

To install Diagram Design, add the marketplace source for your agent, install the plugin, and refresh the plugin cache—three simple steps that work across all Claude-compatible environments.

Diagram Design is an open-source plugin that brings professional diagram generation to AI coding assistants. Whether you're using Claude Code, Codex, Factory Droid, or Pi, this guide walks through the exact installation commands sourced from the cathrynlavery/diagram-design repository.

Understanding Diagram Design's Plugin Architecture

The plugin lives under skills/diagram-design/ in the repository. All agents share these core files, but each consults a different marketplace manifest located in agent-specific directories:

• .claude-plugin/ for Claude Code
• .codex-plugin/ for Codex
• .factory-plugin/ for Factory Droid

After installation, invoke the skill with natural language or slash commands like /diagram-design:import-mermaid and /diagram-design:export-diagram. The core skill definition resides in skills/diagram-design/SKILL.md, which handles command routing and design system specifications.

How to Install Diagram Design in Claude Code

Claude Code users add the marketplace source, install the plugin, and reload.

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

Enable auto-updates via the Marketplaces UI, then run:

/reload-plugins

The manifest at .claude-plugin/plugin.json exposes the plugin to Claude Code's command system.

How to Install Diagram Design in Codex

Codex follows a similar pattern with slightly different CLI syntax:

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

Fetch updates immediately with:

codex plugin marketplace upgrade diagram-design

How to Install Diagram Design in Factory Droid

Factory Droid requires a full repository URL and supports scoped installation:

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

Update to a later commit when needed:

droid plugin marketplace update diagram-design
droid plugin update diagram-design@diagram-design --scope user

How to Install Diagram Design in Pi

Pi offers the simplest installation path:

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

Reload your Pi session to make the new skill visible:

/reload

Editable Local Install for Custom Branding

For development work or custom branding, clone the repository and install from your local copy:

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

For Pi:

pi install ~/code/diagram-design

For Claude Code: Symlink the inner skill directory:

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

The scripts/bump-plugin-version.py helper script synchronizes version numbers across marketplace manifests—useful when maintaining custom forks.

Verifying Your Installation

Confirm successful installation by visiting skills/diagram-design/assets/index.html in your browser. This live gallery displays all 38 supported diagram types and serves as a quick visual verification that the plugin loaded correctly.

Summary

• Three-step pattern works across all agents: add marketplace source → install plugin → refresh cache
• Core files live in skills/diagram-design/ with agent-specific manifests in .claude-plugin/, .codex-plugin/, and .factory-plugin/
• Current version is 2.5.x across all distribution channels
• Editable installs support custom branding via local clones and symlinks
• Post-install access includes 38 diagram types and slash commands like /diagram-design:export-diagram

Frequently Asked Questions

What agents are compatible with Diagram Design?

Diagram Design supports Claude Code, Codex, Factory Droid, and Pi. All share the same core skill files but use different CLI commands and marketplace manifests. The repository provides exact instructions for each at lines 111-118, 124-129, 133-136, 144-146, and 152-164 of the README.

Can I use Diagram Design without an AI agent?

No. Diagram Design is a plugin skill that requires a compatible agent environment to host it. However, you can run it locally for development or custom branding by cloning the repository and using the editable install methods described above.

How do I update Diagram Design to the latest version?

Use your agent's plugin update command: /reload-plugins or the Marketplaces UI for Claude Code, codex plugin marketplace upgrade for Codex, droid plugin marketplace update followed by droid plugin update for Factory Droid. The version bumping script scripts/bump-plugin-version.py ensures consistent versioning across all manifests.

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