claude-cowork-plugin-skill-marketplace-builder

Claude Cowork Plugin Skill Marketplace Builder

A Claude Code plugin that builds complete Claude Cowork plugin marketplaces from a plain-language description and packages them as install-ready zips.

Quick Start

Use the claude-cowork-marketplace-builder skill to generate a multi-plugin office or marketplace from a plain-language request.

Examples of requests it handles:

• "Build a Claude Cowork marketplace for an AI consulting firm"
• "Make me a 6-plugin office for recruiting and staffing"
• "Create a plugin marketplace for legal intake, research, drafting, and review"

How It Works

1. Interpret your marketplace idea as a multi-plugin office
2. Infer a sensible architecture (or use your plugin structure if provided)
3. Normalize the marketplace into a compact JSON spec
4. Generate the complete folder structure and plugin files
5. Package everything as an install-ready zip

Output

The plugin generates a marketplace zip containing:

• Top-level .claude-plugin/marketplace.json — marketplace manifest with plugin references
• Plugin folders — one folder per plugin in your office
  • plugin.json — plugin manifest
  • commands/ — slash commands
  • skills/ — workflow skills with SKILL.md files
  • hooks/hooks.json — hook configuration
  • Optional .mcp.json — official connector configurations
  • README.md — plugin documentation
• Top-level README.md — marketplace overview and usage guide

Design Philosophy

This plugin follows the Claude Cowork principles:

• Skills-first: Each plugin owns a real work lane with practical workflow skills
• Commands as shortcuts: Slash commands layer on top of skills, not vice versa
• Clear boundaries: Plugins represent distinct work lanes, not micro-tasks
• Official connectors only: External integrations use only approved MCP servers
• Production-ready: Generated marketplaces follow Claude plugin structure exactly

File Structure

.
├── .claude-plugin/
│   └── plugin.json                   # This plugin's manifest
├── hooks/
│   └── hooks.json                    # Hook configuration
├── skills/
│   └── claude-cowork-marketplace-builder/
│       └── SKILL.md                  # Main skill documentation
├── scripts/
│   └── build_marketplace_scaffold.py # Core build script
├── references/
│   ├── official-connectors.json      # Official MCP server URLs (source of truth)
│   ├── official-connectors.md        # Selection guidance
│   ├── spec-checklist.md             # Spec JSON field validation
│   ├── plugin-role-patterns.md       # Common plugin types and naming
│   ├── plugin-layouts.md             # Plugin folder structure
│   └── command-examples.md           # Command writing patterns
└── README.md                          # This file

Building a Marketplace Manually

If you want to generate a marketplace programmatically:

python3 scripts/build_marketplace_scaffold.py <spec.json> <output-dir>

Spec JSON Format

{
  "marketplace_name": "Sales Ops Office",
  "owner_name": "Acme Inc",
  "plugins": [
    {
      "name": "sales-operations",
      "description": "Sales operations and pipeline management",
      "role_summary": "Owns the sales workflow, pipeline tracking, and deal management",
      "commands": [
        {
          "name": "account-plan",
          "description": "Build an account plan for strategic selling",
          "skill": "account-plan"
        }
      ],
      "skills": [
        {
          "name": "account-plan",
          "description": "Account planning workflow",
          "deliverable": "Account Plan Document"
        }
      ],
      "connectors": ["slack", "notion"]
    }
  ]
}

See references/spec-checklist.md for complete field documentation.

Input Validation

The build script validates all input before generating. Required fields:

• marketplace_name (string)
• plugins (array)
  • name (string)
  • description (string)
  • commands (array) — each with name, skill
  • skills (array) — each with name, description

Missing or malformed fields produce clear error messages, not cryptic tracebacks.

Official Connectors

This plugin only supports official MCP server connectors. The complete list is in references/official-connectors.json:

• slack — Team communication and channel workflows
• notion — Docs, databases, trackers, task systems
• asana, linear, atlassian, clickup, monday — Task and project management
• ms365 — Microsoft docs, mail, and office ecosystem
• google-calendar — Scheduling and cadence
• gmail — Email outreach and inbox workflows

Never invent custom MCP URLs.

Development

This plugin itself follows the Claude Code plugin structure it generates. All plugin files are in their correct locations per the Claude plugin specification.

Building and Testing

After making changes, test with a sample spec: