Developing Claude Code Plugins

Developing Claude Code Plugins

Overview

This skill provides efficient workflows for creating Claude Code plugins. Use it to make plugin development fast and correct - it synthesizes official docs into actionable steps and provides working examples.

When to Use

Use this skill when:

• Creating a new Claude Code plugin from scratch
• Adding components to an existing plugin (skills, commands, hooks, MCP servers)
• Setting up a development marketplace for testing
• Troubleshooting plugin structure issues
• Understanding plugin architecture and patterns
• Releasing a plugin (versioning, tagging, marketplace distribution)
• Publishing updates or maintaining existing plugins

For comprehensive official documentation, use the working-with-claude-code skill to access full docs.

Quick Reference

Plugin Development Workflow

Phase 1: Plan

Before writing code:

1. Define your plugin's purpose

   • What problem does it solve?
   • Who will use it?
   • What components will it need?

2. Choose your pattern (read references/common-patterns.md)

   • Simple plugin with one skill?
   • MCP integration with guidance?
   • Command collection?
   • Full-featured platform?

3. Review examples

   • examples/simple-greeter-plugin/ - Minimal plugin
   • examples/full-featured-plugin/ - All components
   • Installed plugins in ~/.claude/plugins/

Phase 2: Create Structure

1. Create directories (see references/plugin-structure.md for details):

   mkdir -p my-plugin/.claude-plugin
   mkdir -p my-plugin/skills
   # Add other component directories as needed
   

2. Write plugin.json (required):

   {
     "name": "my-plugin",
     "version": "1.0.0",
     "description": "What your plugin does",
     "author": {"name": "Your Name"}
   }
   

   See references/plugin-structure.md for complete format.

3. Create development marketplace (for local testing):

   Create .claude-plugin/marketplace.json:

   {
     "name": "my-dev",
     "plugins": [{
       "name": "my-plugin",
       "source": "./"
     }]
   }
   

   See references/plugin-structure.md for complete format.

Phase 3: Add Components

Use TodoWrite to track component creation:

Example:

- Create skill: main-workflow
- Add command: /hello
- Configure hooks
- Write README
- Test installation

For each component type, see:

• Format/syntax: references/plugin-structure.md
• When to use: references/common-patterns.md
• Working code: examples/ directory

Phase 4: Test Locally

1. Install for testing:

   /plugin marketplace add /path/to/my-plugin
   /plugin install my-plugin@my-dev
   

   Then restart Claude Code.

2. Test each component:

   • Skills: Ask for tasks matching skill descriptions
   • Commands: Run /your-command
   • MCP servers: Check tools are available
   • Hooks: Trigger relevant events

3. Iterate:

   /plugin uninstall my-plugin@my-dev
   # Make changes
   /plugin install my-plugin@my-dev
   # Restart Claude Code
   

Phase 5: Debug and Refine

If something doesn't work, read references/troubleshooting.md for:

• Plugin not loading
• Skill not triggering
• Command not appearing
• MCP server not starting
• Hooks not firing

Common issues are usually:

• Wrong directory structure
• Hardcoded paths (use ${CLAUDE_PLUGIN_ROOT})
• Forgot to restart Claude Code
• Missing executable permissions on scripts

Phase 6: Release and Distribute

1. Write README with:

   • What the plugin does
   • Installation instructions
   • Usage examples
   • Component descriptions

2. Version your release using semantic versioning:

   • Update version in .claude-plugin/plugin.json
   • Document changes in CHANGELOG.md or RELEASE-NOTES.md
   • Example: "version": "1.2.1" (major.minor.patch)

3. Commit and tag your release:

   git add .
   git commit -m "Release v1.2.1: [brief description]"
   git tag v1.2.1
   git push origin main
   git push origin v1.2.1
   

4. Choose distribution method:

   Option A: Direct GitHub distribution

   • Users add: /plugin marketplace add your-org/your-plugin-repo
   • Your plugin.json serves as the manifest

   Option B: Marketplace distribution (recommended for multi-plugin collections)

   • Create separate marketplace repository
   • Add .claude-plugin/marketplace.json with plugin references:

     {
       "name": "my-marketplace",
       "owner": {"name": "Your Name"},
       "plugins": [{
         "name": "your-plugin",
         "source": {
           "source": "url",
           "url": "https://github.com/your-org/your-plugin.git"
         },
         "version": "1.2.1",
         "description": "Plugin description"
       }]
     }
     

   • Users add: /plugin marketplace add your-org/your-marketplace
   • Update marketplace manifest for each plugin release

   Option C: Private/team distribution

   • Configure in team's .claude/settings.json:

     {
       "extraKnownMarketplaces": {
         "team-tools": {
           "source": {"source": "github", "repo": "your-org/plugins"}
         }
       }
     }
     

5. Test the release:

   # Test fresh installation
   /plugin marketplace add your-marketplace-source
   /plugin install your-plugin@marketplace-name
   # Verify functionality, then clean up
   /plugin uninstall your-plugin@marketplace-name
   

6. Announce and maintain:

   • GitHub releases (optional)
   • Team notifications
   • Monitor for issues and user feedback
   • Plan maintenance updates

Critical Rules

Always follow these (from references/plugin-structure.md):

1. .claude-plugin/ contains ONLY manifests (plugin.json and optionally marketplace.json)

   • ❌ Don't put skills, commands, or other components inside
   • ✅ Put them at plugin root

2. Use ${CLAUDE_PLUGIN_ROOT} for all paths in config files

   • Makes plugin portable across systems
   • Required for hooks, MCP servers, scripts

3. Use relative paths in plugin.json

   • Start with ./
   • Relative to plugin root

4. Make scripts executable

   • chmod +x script.sh
   • Required for hooks and MCP servers

Resources in This Skill

• references/plugin-structure.md - Directory layout, file formats, component syntax
• references/common-patterns.md - When to use each plugin pattern, examples
• references/polyglot-hooks.md - Cross-platform hook wrapper for Windows/macOS/Linux
• references/troubleshooting.md - Debug guide for common issues
• examples/simple-greeter-plugin/ - Minimal working plugin (one skill)
• examples/full-featured-plugin/ - Complete plugin with all components (includes run-hook.cmd)

Cross-References

For deep dives into official documentation, use the working-with-claude-code skill to access:

• plugins.md - Plugin development overview
• plugins-reference.md - Complete API reference
• skills.md - Skill authoring guide
• slash-commands.md - Command format
• hooks.md, hooks-guide.md - Hook system
• mcp.md - MCP server integration
• plugin-marketplaces.md - Distribution

Best Practices

1. Start simple - Begin with minimal structure, add complexity when needed
2. Test frequently - Install → test → uninstall → modify → repeat
3. Use examples - Copy patterns from working plugins
4. Follow conventions - Match style of existing plugins
5. Document everything - Clear README helps users and future you
6. Version properly - Use semantic versioning (major.minor.patch)

Workflow Summary

Plan → Choose pattern, review examples
Create → Make structure, write manifests
Add → Build components (skills, commands, etc.)
Test → Install via dev marketplace
Debug → Use troubleshooting guide
Release → Version, tag, distribute via marketplace
Maintain → Monitor, update, support users

The correct path is the fast path. Use references, follow patterns, test frequently.