DIY Tools MCP Server

A Model Context Protocol (MCP) server that allows you to create custom tools/functions at runtime in any programming language and expose them to Claude or other MCP clients.

Overview

The DIY Tools MCP server enables you to dynamically add custom tools without needing to write a full MCP server. Simply provide the function code, parameters schema, and the server handles the rest - validation, execution, persistence, and MCP protocol integration.

This server bridges the gap between simple function definitions and the MCP protocol, making it easy to extend Claude's capabilities with custom tools written in Python, JavaScript, Bash, Ruby, or TypeScript.

Features

• Dynamic Tool Registration: Add new tools at runtime without restarting the server
• Multi-Language Support: Write functions in Python, JavaScript, Bash, and more
• File-Based Functions: Define functions in separate files for better maintainability
• Automatic Validation: Functions are validated for syntax before registration
• Security Validation: Comprehensive security checks for file-based functions
• Persistence: Registered tools are saved and automatically loaded on server restart
• Type Safety: Full JSON Schema validation for function parameters
• Error Handling: Comprehensive error messages and timeout protection
• Source Code Viewer: Built-in tool to inspect function source code

Installation

# Clone the repository
git clone https://github.com/yourusername/diy-tools-mcp.git
cd diy-tools-mcp

# Install dependencies
npm install

# Build the project
npm run build

Usage

Starting the Server

# Start the server
npm start

# Or for development with auto-reload
npm run dev

Adding Tools

The server provides four built-in tools:

1. add_tool - Register a new custom function
2. remove_tool - Remove a registered function
3. list_tools - List all available custom tools
4. view_source - View the source code of a registered tool

Example: Adding a Python Tool

{
  "name": "calculate_factorial",
  "description": "Calculate the factorial of a number",
  "language": "python",
  "code": "def main(n):\n    if n <= 1:\n        return 1\n    return n * main(n - 1)",
  "parameters": {
    "type": "object",
    "properties": {
      "n": {
        "type": "integer",
        "description": "The number to calculate factorial for",
        "minimum": 0
      }
    },
    "required": ["n"]
  },
  "returns": "The factorial of the input number"
}

Example: Adding a JavaScript Tool

{
  "name": "format_date",
  "description": "Format a date string",
  "language": "javascript",
  "code": "function main({ date, format }) {\n  const d = new Date(date);\n  if (format === 'short') {\n    return d.toLocaleDateString();\n  }\n  return d.toLocaleString();\n}",
  "parameters": {
    "type": "object",
    "properties": {
      "date": {
        "type": "string",
        "description": "Date string to format"
      },
      "format": {
        "type": "string",
        "enum": ["short", "long"],
        "default": "long"
      }
    },
    "required": ["date"]
  }
}

Example: Adding a Bash Tool

{
  "name": "system_info",
  "description": "Get basic system information",
  "languag

... [View full README on GitHub](https://github.com/hesreallyhim/diy-tools-mcp#readme)