OpenSkill

Model Context Protocol (MCP) server that enables Anthropic Skills to work with any coding agent and client that supports MCP servers. Provides skill management and sandboxed execution capabilities.

Overview

OpenSkill makes Anthropic's Claude Code Skills universally accessible across the AI coding ecosystem. It provides a secure, sandboxed execution environment for skills using Docker containers, enabling any MCP-compatible AI assistant to execute skills safely with full isolation, volume mounting, and customizable Docker images.

Watch the demo video

Key Features

• Universal Compatibility: Use Anthropic Skills with any MCP-compatible AI coding agent (Cline, Cursor, Windsurf, VS Code, Zed, Roo Code, Continue, etc.)
• Skill Management: Read and execute skills from .claude/skills/ directory
• Sandboxed Execution: Execute bash commands in isolated Docker containers for security
• Volume Mounting: Mount host directories into containers for file access
• MCP Tools: get-skill and use-skill tools for seamless integration
• CLI Commands: Direct command-line access to all functionality
• Custom Images: Support for custom Docker images tailored to your needs
• Pre-configured Environment: Python (uv, pip, poetry, pipenv, Pillow) and Node.js tooling out of the box
• Performance: Docker image prewarming and container reuse

Installation

Prerequisites

• Node.js 20+
• Docker (for sandboxed skill execution)

Install via npm

npm install -g @agiflowai/openskill

After installation, verify with:

openskill doctor

Download Skills

Download Anthropic's official skills to your project:

# Clone the skills repository
git clone https://github.com/anthropics/skills.git .claude/skills-temp

# Move skills to .claude/skills directory
mkdir -p .claude/skills
cp -r .claude/skills-temp/skills/* .claude/skills/

# Clean up
rm -rf .claude/skills-temp

Or download specific skills manually:

# Create skills directory
mkdir -p .claude/skills

# Clone and copy specific skill (e.g., canvas-design)
git clone https://github.com/anthropics/skills.git /tmp/skills
cp -r /tmp/skills/skills/canvas-design .claude/skills/
rm -rf /tmp/skills

Your skills directory should look like:

.claude/skills/
├── canvas-design/
│   └── SKILL.md
├── python-sandbox/
│   └── SKILL.md
└── ... (other skills)

Usage with MCP Clients

OpenSkill works with any MCP-compatible client. Here are quick setup examples:

Claude Code

{
  "mcpServers": {
    "openskill-mcp": {
      "command": "openskill",
      "args": ["mcp-serve", "--disable-tools", "get-skill"]
    }
  }
}

Cline

{
  "mcpServers": {
    "openskill-mcp": {
      "disabled": false,
      "command": "openskill",
      "args": ["mcp-serve"]
    }
  }
}

Continue

{
  "mcpServers": {
    "openskill-mcp": {
      "command": "openskill",
      "args": ["mcp-serve"]
    }
  }
}

Cursor

Add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "openskill-mcp": {
      "command": "openskill",
      "args": ["mcp-serve"]
    }
  }
}

Gemini CLI

Add to .gemini/settings.json:

{
  "mcpServers": {
    "openskill-mcp": {
      "command": "openskill",
      "args": ["mcp-serve"]
    }
  }
}

Roo Code

{
  "mcpServers": {
    "openskill-mcp": {
      "command": "openskill",
      "args": ["mcp-serve"]
    }
  }
}

VS Code

"mcp": {
  "servers": {
    "openskill-mcp": {
      "type": "stdio",
      "command": "openskill",
      "args": ["mcp-serve"]
    }
  }
}

Windsurf

{
  "mcpServers": {
    "openskill-mcp": {
      "command": "openskill",
      "args": ["mcp-serve"]
    }
  }
}

Zed

{
  "context_servers": {
    "openskill-mcp": {
      "source": "custom",
      "command": "openskill",
      "args": ["mcp-serve"]
    }
  }
}

Note: For advanced configuration options (mount paths, container names, custom Docker images, skills paths, timeouts, etc.), see the CLI Commands section below.

MCP Tools

get-skill

Retrieves skill information from the skills directory. You can use Anthropic's skills from GitHub and put them in .claude/skills or your custom skill folder.

Input:

• command (string): Name of the skill to retrieve

Example:

{
  "command": "canvas-design"
}

use-skill

Executes bash commands in a sandboxed Docker environment for a specific skill.

Input:

• skillName (string): Name of the skill to execute
• bash (string): Bash command to execute

Example:

{
  "skillName": "canvas-design",
  "bash": "python generate.py output.pdf"
}

CLI Commands

mcp-serve

Start the MCP server with stdio transport.

openskill mcp-serve [options]

Options:

• -t, --type <type>: Transport type (default: "stdio")
• --timeout <ms>: Default timeout for use-skill command (default: 30000)
• --workdir <path>: Default working directory in container (default: "/workspace")
• --mount <path>: Host path to mount into container /workspace
• --skills-path <path>: Path to skills directory (default: ".claude/skills")
• --container-name <name>: Custom Docker container name (allows reusing one container for multiple skills)
• --image <name>: Custom Docker image name to use instead of building default openskill-http image
• --disable-tools <tools>: Comma-separated list of tools to disable
• --no-prewarm: Disable Docker image prewarming on server startup

Examples:

# Start with custom skills path
openskill mcp-serve --skills-path ./my-skills

# Start with custom Docker image
openskill mcp-serve --image my-custom-image:latest

# Start with custom container name (reuse same container for all skills)
openskill mcp-serve --container-name shared-skill-container

# Mount current directory
openskill mcp-serve --mount $(pwd)

use-skill

Execute a skill directly from the command line.

openskill use-skill <skill-name> <bash-command> [options]

Options:

• -t, --timeout <ms>: Command timeout (default: 30000)
• -w, --workdir <path>: Working directory (default: "/workspace")
• -m, --mount <path>: Host path to mount into container

Example:

# Execute Python script in canvas-design skill
openskill use-skill canvas-design "python generate.py output.pdf" \
  --mount /Users/username/projects

doctor

Check if Docker is installed and accessible. Validates your environment for running OpenSkill.

openskill doctor

Checks:

• Docker installation and version
• Docker daemon status

Example Output:

Running OpenSkill environment checks...

Checking Docker installation...
✓ Docker is installed: Docker version 28.3.2, build 578ccf6

Checking Docker daemon...
✓ Docker daemon is running

✓ All checks passed!
  Your environment is ready to use OpenSkill.

Docker Environment

The sandbox Docker image includes:

Node.js/JavaScript:

• Node.js v20
• npm

Python:

• Python 3.12
• pip
• uv (fast package installer)
• poetry (dependency management)
• pipenv (virtual environment manager)
• Pillow (PIL - image processing library)

System Tools:

• bash
• git
• curl, wget
• Build tools (gcc, g++, make)

Building the Docker Image

cd packages/openskill
docker build -t openskill-http .

Skill Structure

Skills should be organized in the skills directory (default: .claude/skills/):

.claude/skills/
├── canvas-design/
│   ├── SKILL.md          # Skill definition with frontmatter
│   ├── generate.py       # Skill implementation
│   └── templates/        # Additional resources
└── another-skill/
    └── SKILL.md

SKILL.md Format:

---
name: canvas-design
description: Create beautiful visual art in .png and .pdf documents
license: user
---

# Canvas Design Skill

Instructions for the AI on how to use this skill...

Architecture

• src/tools/: MCP tool implementations (GetSkillTool, UseSkillTool)
• src/services/: Business logic (SkillService, SandboxService)
• src/commands/: CLI commands (mcp-serve, use-skill, http-serve)
• src/server/: MCP server setup and configuration
• src/transports/: MCP transport handlers (stdio)
• Dockerfile: Docker image with Python and Node.js tooling

Development

Project Structure

openskill/
├── packages/
│   └── openskill/     # Main MCP server package
├── nx.json            # Nx configuration
├── pnpm-workspace.yaml  # pnpm workspace configuration
└── tsconfig.base.json  # Base TypeScript configuration

Setup

Prerequisites:

• Node.js 20+
• Docker (for sandboxed skill execution)
• pnpm (v10.15.1 or later)

Installation:

# Install dependencies
pnpm install

# Build the project
pnpm build

Development Workflow

# Run type checking
pnpm typecheck

# Run tests
pnpm test

# Development mode (watch)
pnpm dev

Testing Locally

# Start the MCP server locally
node packages/openskill/dist/cli.js mcp-serve --mount $(pwd)

# Or use with custom Docker image
node packages/openskill/dist/cli.js mcp-serve --image my-custom-image:latest

Available Scripts

• pnpm build - Build all projects
• pnpm test - Run tests for all projects
• pnpm lint - Lint all projects
• pnpm typecheck - Run type checking
• pnpm dev - Development mode with watch
• pnpm graph - View the project dependency graph
• pnpm reset - Reset Nx cache

License

AGPL-3.0

Community

Join our Discord community: https://discord.gg/NsB6q9Vas9