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:

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

Generate manifest with item metadata:
- Name: item name (kebab-case)
- Version: item version
- Description: item description
- Keywords: item tags + plugin names
Generate CLAUDE.md with:
- Item overview and purpose
- Available commands list
- Agent descriptions
- Configuration options
Create ZIP under 50 MB (Cowork limit)
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

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

GitHub Repository

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

Direct Share

Share the ZIP file directly. Recipients install via:

Claude Desktop: drag into Plugins settings
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

plugin-packaging