skills-as-mcp

skills-as-mcp is a TypeScript MCP server that turns Claude-style skill folders into MCP tools, resources, and prompts.

It is inspired by the Python project biocontext-ai/skill-to-mcp, but built for the TypeScript ecosystem and aligned with the official Model Context Protocol server guidance.

What it does

• Recursively discovers SKILL.md files from one or many skill roots
• Parses YAML frontmatter for name and description
• Exposes three core MCP tools:
  • get_available_skills
  • get_skill_details
  • get_skill_related_file
• Exposes MCP resources for the catalog and each discovered skill
• Exposes a use_skill prompt for clients that support prompts
• Supports:
  • stdio for local coding tools and desktop clients
  • http for Streamable HTTP on /mcp
  • sse for a compatibility server that exposes /mcp, /sse, and /messages

Installation

Run it directly with npx:

npx skills-as-mcp --skills-dir /absolute/path/to/skills --type stdio

Or install it into a project:

npm install skills-as-mcp

Quick Start

1. Create a skill directory

Your skills can live anywhere. Each skill needs its own directory and a SKILL.md file with frontmatter:

my-skills/
└── release-helper/
    ├── SKILL.md
    ├── references/
    └── scripts/

---
name: release-helper
description: Helps prepare package releases and changelogs.
---

# Release Helper

Instructions go here...

2. Run as a local MCP server

npx skills-as-mcp --skills-dir /absolute/path/to/my-skills --type stdio

3. Run as a remote server

Streamable HTTP only:

npx skills-as-mcp --skills-dir /absolute/path/to/my-skills --type http --host 0.0.0.0 --port 3000

Compatibility mode with legacy SSE:

npx skills-as-mcp --skills-dir /absolute/path/to/my-skills --type sse --host 0.0.0.0 --port 3000

In sse mode the server exposes:

• /mcp for Streamable HTTP clients
• /sse for legacy SSE clients
• /messages for legacy POST requests

CLI Reference

npx skills-as-mcp --skills-dir <path> [--skills-dir <path> ...] --type <stdio|http|sse>

Options

• --skills-dir <path>: Add a skill root. Repeat the flag to load multiple roots.
• --type <stdio|http|sse>: Select the transport mode.
• --host <host>: Host interface for HTTP modes. Default: 127.0.0.1.
• --port <port>: Port for HTTP modes. Default: 3000.

Environment variables

• SKILLS_DIR: Single skill root
• SKILLS_DIRS: Multiple skill roots joined by your OS path delimiter
• SKILLS_AS_MCP_TYPE: Same values as --type
• SKILLS_AS_MCP_HOST: Same as --host
• SKILLS_AS_MCP_PORT: Same as --port

SKILLS_DIRS uses : on macOS/Linux and ; on Windows.

MCP Surface Area

Tools

get_available_skills

• Returns every discovered skill with name, description, and path

get_skill_details

• Returns the SKILL.md content and the recursive file listing for a skill
• Supports return_type values of content, file_path, and both

get_skill_related_file

• Reads a specific file inside a skill directory
• Blocks directory traversal outside the skill root
• Supports return_type values of content, file_path, and both

Resources

• skills://catalog
• skills://<skill-name>

Prompts

• use_skill

Example MCP Client Config

For clients that spawn local MCP servers over stdio, the shape is typically:

{
  "mcpServers": {
    "skills-as-mcp": {
      "command": "npx",
      "args": [
        "skills-as-mcp",
        "--skills-dir",
        "/absolute/path/to/my-skills",
        "--type",
        "stdio"
      ]
    }
  }
}

For multiple skill roots:

{
  "mcpServers": {
    "skills-as-mcp": {
      "command": "npx",
      "args": [
        "skills-as-mcp",
        "--skills-dir",
        "/absolute/path/to/team-skills",
        "--skills-dir",
        "/absolute/path/to/project-skills",
        "--type",
        "stdio"
      ]
    }
  }
}

Included Example

An example skill is included at examples/skills/example-skill/SKILL.md so you can try the package immediately:

npx skills-as-mcp --skills-dir ./examples/skills --type stdio

Library Usage

You can also import the core pieces directly:

import { SkillRegistry, createSkillsMcpServer } from "skills-as-mcp";

const registry = await SkillRegistry.fromSkillRoots(["./examples/skills"]);
const server = createSkillsMcpServer({ registry });

Development

npm install
npm run lint
npm test
npm run build

Useful commands:

• npm run dev -- --skills-dir ./examples/skills --type stdio
• npm run dev -- --skills-dir ./examples/skills --type http --port 3000
• npm run dev -- --skills-dir ./examples/skills --type sse --port 3000

Notes

• Invalid skills are skipped with warnings instead of crashing the whole server.
• Duplicate skill names across roots are treated as a startup error.
• In stdio mode all human-readable logs go to stderr so MCP traffic on stdout stays clean.