Plugin Packaging Knowledge

Domain knowledge for packaging marketplace items as Cowork-compatible plugins for distribution.

Use For

• Exporting marketplace items as standalone plugin ZIPs
• Preparing plugins for Claude Desktop private marketplace upload
• Understanding Cowork plugin format requirements
• Validating plugin packages before distribution

Cowork Plugin Format

Claude Desktop Cowork uses the same plugin format as Claude Code:

plugin-name/
├── .claude-plugin/
│   └── plugin.json          # Required: manifest
├── .mcp.json                # Optional: MCP server connections
├── commands/
│   ├── command-name.md      # Slash commands
│   └── index.json           # Command index
├── skills/
│   └── skill-name/
│       └── SKILL.md         # Domain knowledge
├── agents/
│   └── agent-name.md        # Sub-agent definitions
├── CLAUDE.md                # Plugin-level instructions
└── README.md                # User documentation

Manifest Format (plugin.json)

{
  "name": "plugin-name",
  "version": "1.0.0",
  "description": "One-line description",
  "author": {
    "name": "Author Name",
    "email": "email@example.com"
  },
  "license": "MIT",
  "keywords": ["keyword1", "keyword2"]
}

Rules:

• Name must be lowercase kebab-case
• Version follows semver
• Description should be under 100 characters

Export Process

When exporting a marketplace item:

1. Collect source files from bound plugins:

   For each pluginBinding:
     agents/ → copy referenced agent .md files
     skills/ → copy referenced skill directories
     commands/ → copy referenced command .md files
   

2. Generate manifest with item metadata:

   • Name: item name (kebab-case)
   • Version: item version
   • Description: item description
   • Keywords: item tags + plugin names

3. Generate CLAUDE.md with:

   • Item overview and purpose
   • Available commands list
   • Agent descriptions
   • Configuration options

4. Create ZIP under 50 MB (Cowork limit)

5. Validate the package:

   • plugin.json exists and is valid JSON
   • All referenced files exist
   • No secrets or .env files included
   • ZIP is under 50 MB

Distribution Channels

Claude Desktop Private Marketplace

1. Go to Organization Settings > Plugins
2. Click "Add plugins" > "Upload to a new marketplace"
3. Upload the ZIP file
4. Assign to users/teams

GitHub Repository

1. Push plugin to a GitHub repo
2. Add marketplace: claude plugin marketplace add org/repo
3. Install: claude plugin install name@marketplace

Direct Share

Share the ZIP file directly. Recipients install via:

1. Claude Desktop: drag into Plugins settings
2. CLI: claude plugin install ./path/to/plugin.zip

Validation Checklist

Before distributing:

• plugin.json has valid name, version, description
• All command .md files have proper YAML frontmatter
• All skill SKILL.md files have triggers defined
• All agent .md files specify model and allowed-tools
• No hardcoded secrets, API keys, or credentials
• ZIP is under 50 MB
• README.md exists with usage instructions