MCP File & URL Tools

A clean, production-ready MCP (Model Context Protocol) server built with Node.js that provides two essential tools: read_file and fetch_url.

Features

• read_file: Read local files and return their contents as text
• fetch_url: Perform HTTP GET requests with timeout and error handling
• Clean, modular architecture
• Full MCP protocol compliance
• Simple test client included

Project Structure

.
├── src/
│   ├── server.js          # MCP server setup and routing
│   └── tools/
│       ├── readFile.js    # read_file tool implementation
│       └── fetchUrl.js    # fetch_url tool implementation
├── client/
│   └── testClient.js     # Simple test client
├── package.json
└── README.md

Installation

1. Install Node.js 18+ (for native fetch support)

2. Install dependencies:

npm install

Usage

Running the MCP Server

The server uses stdio transport and follows the MCP protocol:

npm start
# or
node src/server.js

Testing with the Test Client

Run the included test client:

npm test
# or
node client/testClient.js

Tools

Tool 1: read_file

Read a local file and return its contents as text.

Input:

{
  "path": "/path/to/file.txt"
}

Output: Returns the file contents as plain text in the MCP response format.

Error Handling:

• File not found (ENOENT)
• Permission denied (EACCES)
• Path is a directory (EISDIR)
• Other file system errors

Tool 2: fetch_url

Perform a GET request to a URL and return the response.

Input:

{
  "url": "https://example.com"
}

Output: Returns a JSON object containing:

• status: HTTP status code
• statusText: HTTP status text
• headers: Response headers
• body: Response body as text

Features:

• 10 second timeout to prevent hanging requests
• Basic URL validation
• Network error handling
• User-Agent header included

MCP Client Configuration

To use this server with an MCP client, configure it as follows:

{
  "mcpServers": {
    "file-url-tools": {
      "command": "node",
      "args": ["path/to/src/server.js"]
    }
  }
}

Design Decisions

Architecture

• Modular structure: Tools are separated into individual modules for maintainability
• Error handling: Consistent error handling across all tools with clear error messages
• MCP compliance: Uses official MCP SDK and follows protocol specifications

read_file Tool

• Uses fs/promises for async file operations
• UTF-8 encoding only (text files)
• Path resolution for relative paths

fetch_url Tool

• Uses Node.js built-in fetch (Node 18+)
• 10 second timeout via AbortController
• Returns complete response info (status, headers, body)

License

MIT