Create Cowork Plugin
AnthropicOfficialPublished by Anthropic
- Skill
- Workflow
- Agent tooling
- Apache-2.0
- No issues found
AutoGineer summary
Written by AutoGineer from the skill’s own files, not by the author
This skill provides a structured, conversational approach to creating plugins for the Cowork desktop app. It guides users through the entire lifecycle of plugin development, from initial discovery and component planning to design, implementation, and final packaging. By following this workflow, users can create modular, well-structured plugins that include skills, MCP server integrations, and agents, ultimately resulting in a ready-to-install .plugin file.
What it does
- Facilitates a five-phase development process: discovery, planning, design, implementation, and review.
- Helps define and structure plugin components like skills, agents, and MCP servers.
- Ensures adherence to required directory layouts and manifest file standards.
- Provides guidance on writing effective skill descriptions and imperative-style instructions.
- Automates the final packaging step by creating a validated .plugin file.
- Supports the creation of portable, tool-agnostic plugins using placeholder patterns.
When to use it
- When you need to build a new plugin from scratch for the Cowork environment.
- When you want to scaffold a plugin with specific skills, agents, or external tool integrations.
- When you are unsure about the required directory structure or manifest requirements for a plugin.
- When you need to package your developed components into a distributable .plugin file.
Advantages
- Ensures consistent plugin architecture and adherence to best practices.
- Reduces complexity by breaking down development into manageable, guided phases.
- Promotes the use of progressive disclosure for skill documentation.
- Simplifies the packaging process with automated validation and compression.
- Encourages modular design by helping users plan only the necessary components.
Usage examples
- “I want to create a new plugin to help me manage my project tasks.”
- The agent initiates the discovery phase, asking about the plugin's purpose, target users, and any necessary external tool integrations.
- “Can you help me build a plugin that integrates with my database?”
- The agent guides you through planning the MCP server component and defining the necessary skills to interact with the database.
Install
Download the skill as a ZIP:
https://autogineer.com/agent-skills/anthropics/create-cowork-plugin/downloadUnzip it into the cross-client skills folder of your project:
mkdir -p .agents/skills && unzip create-cowork-plugin.zip -d .agents/skills
Documentation by Anthropic
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:
Discovery — understand what the user wants to build
Component Planning — determine which component types are needed
Design & Clarifying Questions — specify each component in detail
Implementation — create all plugin files
Review & Package — deliver the
.pluginfile
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 documentationLegacy
commands/format: Older plugins may include acommands/directory with single-file.mdslash commands. This format still works, but new plugins should useskills/*/SKILL.mdinstead — the Cowork UI presents both as a single "Skills" concept, and the skills format supports progressive disclosure viareferences/.
Rules:
.claude-plugin/plugin.jsonis always requiredComponent 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:
| Component | Location | Format |
|---|---|---|
| Skills | skills/*/SKILL.md | Markdown + YAML frontmatter |
| MCP Servers | .mcp.json | JSON |
| Agents (uncommonly used in Cowork) | agents/*.md | Markdown + YAML frontmatter |
| Hooks (rarely used in Cowork) | hooks/hooks.json | JSON |
| Commands (legacy) | commands/*.md | Markdown + YAML frontmatter |
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.
Customizable plugins with ~~ placeholders
Do not use or ask about this pattern by default. Only introduce
~~placeholders if the user explicitly says they want people outside their organization to use the plugin. You can mention this is an option if it seems like the user wants to distribute the plugin externally, but do not proactively ask about this with AskUserQuestion.
When a plugin is intended to be shared with others outside their company, it might have parts that need to be adapted to individual users.
You might need to reference external tools by category rather than specific product (e.g., "project tracker" instead of "Jira").
When sharing is needed, use generic language and mark these as requiring customization with two tilde characters such as create an issue in ~~project tracker.
If used any tool categories, write a CONNECTORS.md file at the plugin root to explain:
# Connectors
## How tool references work
Plugin files use `~~category` as a placeholder for whatever tool the user
connects in that category. Plugins are tool-agnostic — they describe
workflows in terms of categories rather than specific products.
## Connectors for this plugin
| Category | Placeholder | Options |
| --------------- | ------------------- | ------------------------------- |
| Chat | `~~chat` | Slack, Microsoft Teams, Discord |
| Project tracker | `~~project tracker` | Linear, Asana, Jira |${CLAUDE_PLUGIN_ROOT} Variable
Use ${CLAUDE_PLUGIN_ROOT} for all intra-plugin path references in hooks and MCP configs. Never hardcode absolute paths.
Guided Workflow
When you ask the user something, use AskUserQuestion. Don't assume "industry standard" defaults are correct. Note: AskUserQuestion always includes a Skip button and a free-text input box for custom answers, so do not include None or Other as options.
Phase 1: Discovery
Goal: Understand what the user wants to build and why.
Ask (only what is unclear — skip questions if the user's initial request already answers them):
What should this plugin do? What problem does it solve?
Who will use it and in what context?
Does it integrate with any external tools or services?
Is there a similar plugin or workflow to reference?
Summarize understanding and confirm before proceeding.
Output: Clear statement of plugin purpose and scope.
Phase 2: Component Planning
Goal: Determine which component types the plugin needs.
Based on the discovery answers, determine:
Skills — Does it need specialized knowledge that Claude should load on-demand, or user-initiated actions? (domain expertise, reference schemas, workflow guides, deploy/configure/analyze/review actions)
MCP Servers — Does it need external service integration? (databases, APIs, SaaS tools)
Agents (uncommon) — Are there autonomous multi-step tasks? (validation, generation, analysis)
Hooks (rare) — Should something happen automatically on certain events? (enforce policies, load context, validate operations)
Present a component plan table, including component types you decided not to create:
| Component | Count | Purpose |
|-----------|-------|---------|
| Skills | 3 | Domain knowledge for X, /do-thing, /check-thing |
| Agents | 0 | Not needed |
| Hooks | 1 | Validate writes |
| MCP | 1 | Connect to service Y |Get user confirmation or adjustments before proceeding.
Output: Confirmed list of components to create.
Phase 3: Design & Clarifying Questions
Goal: Specify each component in detail. Resolve all ambiguities before implementation.
For each component type in the plan, ask targeted design questions. Present questions grouped by component type. Wait for answers before proceeding.
Skills:
What user queries should trigger this skill?
What knowledge domains does it cover?
Should it include reference files for detailed content?
If the skill represents a user-initiated action: what arguments does it accept, and what tools does it need? (Read, Write, Bash, Grep, etc.)
Agents:
Should each agent trigger proactively or only when requested?
What tools does it need?
What should the output format be?
Hooks:
Which events? (PreToolUse, PostToolUse, Stop, SessionStart, etc.)
What behavior — validate, block, modify, add context?
Prompt-based (LLM-driven) or command-based (deterministic script)?
MCP Servers:
What server type? (stdio for local, SSE for hosted with OAuth, HTTP for REST APIs)
What authentication method?
What tools should be exposed?
If the user says "whatever you think is best," provide specific recommendations and get explicit confirmation.
Output: Detailed specification for every component.
Phase 4: Implementation
Goal: Create all plugin files following best practices.
Order of operations:
Create the plugin directory structure
Create
plugin.jsonmanifestCreate each component (see
references/component-schemas.mdfor exact formats)Create
README.mddocumenting the plugin
Implementation guidelines:
Skills use progressive disclosure: lean SKILL.md body (under 3,000 words), detailed content in
references/. Frontmatter description must be third-person with specific trigger phrases. Skill bodies are instructions FOR Claude, not messages to the user — write them as directives about what to do.Agents need a description with
<example>blocks showing triggering conditions, plus a system prompt in the markdown body.Hooks config goes in
hooks/hooks.json. Use${CLAUDE_PLUGIN_ROOT}for script paths. Prefer prompt-based hooks for complex logic.MCP configs go in
.mcp.jsonat plugin root. Use${CLAUDE_PLUGIN_ROOT}for local server paths. Document required env vars in README.
Phase 5: Review & Package
Goal: Deliver the finished plugin.
Summarize what was created — list each component and its purpose
Ask if the user wants any adjustments
Run
claude plugin validate <path-to-plugin-json>to check the plugin structure. If this command is unavailable (e.g., when running inside Cowork), verify the structure manually:.claude-plugin/plugin.jsonexists and contains valid JSON with at least anamefieldThe
namefield is kebab-case (lowercase letters, numbers, and hyphens only)Any component directories referenced by the plugin (
commands/,skills/,agents/,hooks/) actually exist and contain files in the expected formats —.mdfor commands/skills/agents,.jsonfor hooksEach skill subdirectory contains a
SKILL.mdReport what passed and what didn't, the same way the CLI validator would
Fix any errors before proceeding.
Package as a
.pluginfile:
cd /path/to/plugin-dir && zip -r /tmp/plugin-name.plugin . -x "*.DS_Store" && cp /tmp/plugin-name.plugin /path/to/outputs/plugin-name.pluginImportant: Always create the zip in
/tmp/first, then copy to the outputs folder. Writing directly to the outputs folder may fail due to permissions.
Naming: Use the plugin name from
plugin.jsonfor the.pluginfile (e.g., if name iscode-reviewer, outputcode-reviewer.plugin).
The .plugin file will appear in the chat as a rich preview where the user can browse the files and accept the plugin by pressing a button.
Best Practices
Start small: Begin with the minimum viable set of components. A plugin with one well-crafted skill is more useful than one with five half-baked components.
Progressive disclosure for skills: Core knowledge in SKILL.md, detailed reference material in
references/, working examples inexamples/.Clear trigger phrases: Skill descriptions should include specific phrases users would say. Agent descriptions should include
<example>blocks.Skills are for Claude: Write skill body content as instructions for Claude to follow, not documentation for the user to read.
Imperative writing style: Use verb-first instructions in skills ("Parse the config file," not "You should parse the config file").
Portability: Always use
${CLAUDE_PLUGIN_ROOT}for intra-plugin paths, never hardcoded paths.Security: Use environment variables for credentials, HTTPS for remote servers, least-privilege tool access.
Additional Resources
references/component-schemas.md— Detailed format specifications for every component type (skills, agents, hooks, MCP, legacy commands, CONNECTORS.md)references/example-plugins.md— Three complete example plugin structures at different complexity levels
Files
- ATTRIBUTION.mdAdded by AutoGineer1000 B
- LICENSELicence file added by AutoGineer11.1 KiB
- SKILL.md13.0 KiB
- references/component-schemas.md11.4 KiB
- references/example-plugins.md8.1 KiB
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Requirements and compatibility
Written for: Claude Code, Claude apps
Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta
“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.
Needs: Names Claude Code tools, Needs an MCP server
The author says: Requires Cowork desktop app environment with access to the outputs directory for delivering .plugin files.
Security
No issues found by our static scan· No issues found
A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.
Attribution and licence
- Published by
- Anthropic
- Publisher
- Anthropic (Official)
- Source
- anthropics/knowledge-work-plugins · cowork-plugin-management/skills/create-cowork-plugin · commit e050c2e
- Licence
- Apache License 2.0 (redistribution allowed)
- LICENSE (added by AutoGineer from cowork-plugin-management/LICENSE)
- ATTRIBUTION.md (written by AutoGineer)
- Synced
AutoGineer is not affiliated with or endorsed by Anthropic or Anthropic.
Download ZIP
The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download create-cowork-plugin.zip