api-guardian

Claude Code Private Marketplace Demo

A teaching project that shows how to build a private plugin marketplace for Claude Code. Contains two example plugins with agents, commands, and skills -- everything you need to understand the plugin architecture and start building your own.

What This Demo Shows

If you have been looking at Claude Code plugins and wondering "how do I actually structure a private marketplace for my team?" -- this is your reference. The repository demonstrates:

• How to create a marketplace manifest (marketplace.json) that lists and distributes plugins
• How to structure plugins with agents, commands, and skills
• How plugins, project config (CLAUDE.md), and settings work together to form the full Claude Code experience

This is a demo. The plugins here are illustrative -- they show the correct file structure and conventions, not production-ready tooling. Use this as a starting point, then refer to the official docs linked below for the full specification.

Project Structure

demo-claude-marketplace/
├── .claude-plugin/
│   └── marketplace.json          # Marketplace manifest -- lists all plugins
├── claude-plugins/
│   ├── data-toolkit/
│   │   ├── .claude-plugin/
│   │   │   └── plugin.json       # Plugin metadata (name, description, version)
│   │   ├── agents/               # Subagent definitions (data-engineer, pipeline-architect)
│   │   ├── commands/             # Slash commands (ingest, transform)
│   │   └── skills/               # Skills organized by domain (sql/, etl/)
│   ├── api-guardian/
│   │   ├── .claude-plugin/
│   │   │   └── plugin.json
│   │   ├── agents/               # Subagent definitions (security-auditor, api-reviewer)
│   │   ├── commands/             # Slash commands (audit, scan)
│   │   └── skills/               # Skills organized by domain (openapi/, security/)
│   ├── prompt-craft/
│   │   ├── .claude-plugin/
│   │   │   └── plugin.json
│   │   ├── agents/               # Subagent definitions (prompt-engineer, prompt-evaluator)
│   │   ├── commands/             # Slash commands (craft, optimize)
│   │   └── skills/               # Skills organized by domain (prompting/, few-shot/)
│   ├── code-quality/
│   │   ├── .claude-plugin/
│   │   │   └── plugin.json
│   │   ├── agents/               # Subagent definitions (code-reviewer, refactor-guide)
│   │   ├── commands/             # Slash commands (review, refactor)
│   │   └── skills/               # Skills organized by domain (review/, refactoring/)
│   └── dev-rules/
│       ├── .claude-plugin/
│       │   └── plugin.json
│       ├── agents/               # Subagent definitions (rules-enforcer, standards-advisor)
│       ├── commands/             # Slash commands (check, define)
│       └── skills/               # Skills organized by domain (standards/, ai-guidelines/)
├── CLAUDE.md                     # Project-level memory and conventions
└── README.md

How Plugin Marketplaces Work

A marketplace is a Git repository with a .claude-plugin/marketplace.json at its root. This manifest declares the marketplace name, owner, and lists all available plugins with their relative source paths.

Here is the manifest from this demo:

{
  "name": "demo-marketplace",
  "owner": {
    "name": "Demo Author",
    "email": "[email protected]"
  },
  "plugins": [
    {
      "name": "data-toolkit",
      "source": "./claude-plugins/data-toolkit",
      "description": "Adds data engineering agents, commands, and skills for ETL pipeline development."
    },
    {
      "name": "api-guardian",
      "source": "./claude-plugins/api-guardian",
      "description": "Adds API security auditing agents, commands, and skills for governance and OWASP compliance."
    },
    {
      "name": "prompt-craft",
      "source": "./claude-plugins/prompt-craft",
      "description": "Adds AI prompt engineering agents, commands, and skills for designing, optimizing, and evaluating prompts."
    },
    {
      "name": "code-quality",
      "source": "./claude-plugins/code-quality",
      "description": "Adds code review and refactoring agents, commands, and skills for maintaining high code quality standards."
    },
    {
      "name": "dev-rules",
      "source": "./claude-plugins/dev-rules",
      "description": "Adds development rules, coding standards, and AI behavior guidelines agents, commands, and skills."
    }
  ]
}

Users add the marketplace and install plugins like this:

# Add this marketplace (from a Git repo URL or local path)
/plugin marketplace add ./path/to/demo-claude-marketplace

# Install a specific plugin
/plugin install data-toolkit@demo-marketplace

For private repositories, Claude Code uses your existing git credential helpers. If git clone works in your terminal, it works in Claude Code.

What Plugins Provide

Each plugin is a directory with .claude-plugin/plugin.json at its root, plus any combination of these components: