Create Cowork Plugin

Build a new plugin from scratch through guided conversation. Walk the user through discovery, planning, design, implementation, and packaging — delivering a ready-to-install .plugin file at the end.

Overview

A plugin is a self-contained directory that extends Claude's capabilities with skills, agents, hooks, and MCP server integrations. This skill encodes the full plugin architecture and a five-phase workflow for creating one conversationally.

The process:

1. Discovery — understand what the user wants to build
2. Component Planning — determine which component types are needed
3. Design & Clarifying Questions — specify each component in detail
4. Implementation — create all plugin files
5. Review & Package — deliver the .plugin file

Nontechnical output: Keep all user-facing conversation in plain language. Do not expose implementation details like file paths, directory structures, or schema fields unless the user asks. Frame everything in terms of what the plugin will do.

Plugin Architecture

Directory Structure

Every plugin follows this layout:

plugin-name/
├── .claude-plugin/
│   └── plugin.json           # Required: plugin manifest
├── skills/                   # Skills (subdirectories with SKILL.md)
│   └── skill-name/
│       ├── SKILL.md
│       └── references/
├── agents/                   # Subagent definitions (.md files)
├── .mcp.json                 # MCP server definitions
└── README.md                 # Plugin documentation

Legacy commands/ format: Older plugins may include a commands/ directory with single-file .md slash commands. This format still works, but new plugins should use skills/*/SKILL.md instead — the Cowork UI presents both as a single "Skills" concept, and the skills format supports progressive disclosure via references/.

Rules:

• .claude-plugin/plugin.json is always required
• Component directories (skills/, agents/) go at the plugin root, not inside .claude-plugin/
• Only create directories for components the plugin actually uses
• Use kebab-case for all directory and file names

plugin.json Manifest

Located at .claude-plugin/plugin.json. Minimal required field is name.

{
  "name": "plugin-name",
  "version": "0.1.0",
  "description": "Brief explanation of plugin purpose",
  "author": {
    "name": "Author Name"
  }
}

Name rules: kebab-case, lowercase with hyphens, no spaces or special characters. Version: semver format (MAJOR.MINOR.PATCH). Start at 0.1.0.

Optional fields: homepage, repository, license, keywords.

Custom component paths can be specified (supplements, does not replace, auto-discovery):

{
  "commands": "./custom-commands",
  "agents": ["./agents", "./specialized-agents"],
  "hooks": "./config/hooks.json",
  "mcpServers": "./.mcp.json"
}

Component Schemas

Detailed schemas for each component type are in references/component-schemas.md. Summary:

This schema is shared with Claude Code's plugin system, but you're creating a plugin for Claude Cowork, a desktop app for doing knowledge work. Cowork users will usually find skills the most useful. Scaffold new plugins with skills/*/SKILL.md — do not create commands/ unless the user explicitly needs the legacy single-file format.

…