Run TypeScript Skills MCP Server

An MCP server that lets AI agents execute TypeScript code with access to modular APIs in ~/.claude/skills.

What This Enables

This MCP server provides one tool: run-skill-code. When enabled, your AI agent can execute TypeScript code that imports and calls functions from ~/.claude/skills.

Why You Might Want This

Fast programmatic workflows: Instead of your agent repeatedly calling command-line tools (slow, text parsing), it can call TypeScript functions directly and get structured data back.

Richer agent capabilities: If you've built TypeScript APIs for task management, version control workflows, data processing, or other tooling in ~/.claude/skills, this lets agents use them programmatically.

Better performance: In-process execution is much faster than spawning processes for every operation.

Type-safe interactions: Your agent gets structured results with proper types instead of parsing text output.

Why You Might Not Want This

Security risk: Code executes in-process with full file system access and no sandboxing. If your agent writes malicious code (or makes mistakes), it runs with your permissions.

Limited use case: Only useful if you have (or plan to build) TypeScript APIs in ~/.claude/skills. If you don't, this MCP provides no value.

Trust requirement: You must trust your AI agent to write and execute code safely. There's no safety net.

Development overhead: You need to build and maintain the TypeScript APIs yourself.

When to Use This

Good fit:

• You have TypeScript APIs in ~/.claude/skills that you want agents to use
• You trust your AI agent to execute code safely
• You want fast, programmatic workflows
• You're comfortable with the security tradeoffs

Not a good fit:

• You don't have any skills/APIs for the agent to call
• You're uncomfortable with in-process code execution
• You need sandboxing or security isolation
• You prefer command-line tools

Installation

Prerequisites

• Bun v1.0.0 or later

Setup

git clone <repository-url>
cd run-typescript-skills-mcp
bun install
bun run build

Configure Your MCP Client

VS Code (.vscode/settings.json):

{
  "mcp": {
    "servers": {
      "run-typescript-skills": {
        "command": "bun",
        "args": ["/absolute/path/to/run-typescript-skills-mcp/src/mcp-bun.ts"]
      }
    }
  }
}

Claude Desktop:

{
  "mcpServers": {
    "run-typescript-skills": {
      "command": "bun",
      "args": ["/absolute/path/to/run-typescript-skills-mcp/src/mcp-bun.ts"]
    }
  }
}

What Your Agent Can Do

Once enabled, your agent can execute TypeScript code like:

import { createTask } from '~/.claude/skills/my-workflow/src/api.js';

const task = await createTask({
  title: "Write documentation",
  priority: 1
});

return task;

The agent gets back structured data:

{
  "returnValue": { "id": "task-123", "title": "Write documentation", "priority": 1 },
  "stdout": "",
  "stderr": ""
}

Security Model

⚠️ No sandboxing: Code runs in-process with full system access.

⚠️ Same permissions as server: If the MCP server can access a file, so can the executed code.

⚠️ Trust-based: You're trusting your AI agent to write safe code.

This is designed for: Controlled environments where you trust your agent and want fast, programmatic access to your own TypeScript APIs.

This is NOT designed for: Executing untrusted code, multi-user environments, or situations requiring isolation.

Development

bun run build        # Compile TypeScript
bun run dist         # Build optimized bundle
bun test             # Run tests
bun run dev          # Development mode with MCP Inspector

Architecture

• src/mcp-bun.ts - MCP server entry point
• src/tools/run-skill-code-mcp.ts - Tool registration
• src/tools/run-skill-code.ts - Public API
• src/tools/run-skill-code-impl.ts - Implementation

See docs/adr/ for architectural decisions.

License

MIT License - see LICENSE file for details.

Links

• Model Context Protocol
• Bun Runtime