MCP URL Format Converter

A Model Context Protocol (MCP) server that fetches content from any URL and converts it to your desired output format.

Overview

MCP URL Format Converter provides tools for retrieving content from any web URL and transforming it into various formats (HTML, JSON, Markdown, or plain text), regardless of the original content type. It’s designed to work with any MCP-compatible client, including Claude for Desktop, enabling LLMs to access, transform, and analyze web content in a consistent format.

Features

• Format Conversion: Transform any web content to HTML, JSON, Markdown, or plain text
• Universal Input Support: Handle websites, APIs, raw files, and more
• Automatic Content Detection: Intelligently identifies source format
• Robust Library Support: Uses industry-standard libraries:
  • Cheerio for HTML parsing
  • Marked for Markdown processing
  • Fast-XML-Parser for XML handling
  • CSVtoJSON for CSV conversion
  • SanitizeHTML for security
  • Turndown for HTML-to-Markdown conversion
• Advanced Format Processing:
  • HTML parsing with metadata extraction
  • JSON pretty-printing and structure preservation
  • Markdown rendering with styling
  • CSV-to-table conversion
  • XML-to-JSON transformation
• History Tracking: Maintains logs of recently fetched URLs
• Security Focus: Content sanitization to prevent XSS attacks

Installation

Prerequisites

• Node.js 16.x or higher
• npm or yarn

Quick Start

1. Clone the repository:

   git clone https://github.com/yourusername/mcp-url-converter.git
   cd mcp-url-converter
   

2. Install dependencies:

   npm install
   

3. Build the project:

   npm run build
   

4. Run the server:

   npm start
   

Integration with Claude for Desktop

1. Open your Claude for Desktop configuration file:

   • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
   • Windows: %APPDATA%Claudeclaude_desktop_config.json

2. Add the URL converter server to your configuration:

   {
     "mcpServers": {
       "url-converter": {
         "command": "node",
         "args": ["/absolute/path/to/mcp-url-converter/build/index.js"]
       }
     }
   }
   

3. Restart Claude for Desktop

Available Tools

fetch

Fetches content from any URL and automatically detects the best output format.

Parameters:

• url (string, required): The URL to fetch content from
• format (string, optional): Format to convert to (auto, html, json, markdown, text). Default: auto

Example:

Can you fetch https://example.com and choose the best format to display it?

fetch-json

Fetches content from any URL and converts it to JSON format.

Parameters:

• url (string, required): The URL to fetch content from
• prettyPrint (boolean, optional): Whether to pretty-print the JSON. Default: true

Example:

Can you fetch https://example.com and convert it to JSON format?

fetch-html

Fetches content from any URL and converts it to HTML format.

Parameters:

• url (string, required): The URL to fetch content from
• extractText (boolean, optional): Whether to extract text content only. Default: false

Example:

Can you fetch https://api.example.com/users and convert it to HTML?

fetch-markdown

Fetches content from any URL and converts it to Markdown format.

Parameters:

• url (string, required): The URL to fetch content from

Example:

Can you fetch https://example.com and convert it to Markdown?

fetch-text

Fetches content from any URL and converts it to plain text format.

Parameters:

• url (string, required): The URL to fetch content from

Example:

Can you fetch https://example.com and convert it to plain text?

web-search and deep-research

These tools provide interfaces to Perplexity search capabilities (when supported by the MCP host).

Available Resources

recent-urls://list

Returns a list of recently fetched URLs with timestamps and output formats.

Example:

What URLs have I fetched recently?

Security

This server implements several security measures:

• HTML sanitization using sanitize-html to prevent XSS attacks
• Content validation before processing
• Error handling and safe defaults
• Input parameter validation with Zod
• Safe output encoding

Testing

You can test the server using the MCP Inspector:

npm run test

Troubleshooting

Common Issues

1. Connection errors: Verify that the URL is accessible and correctly formatted
2. Conversion errors: Some complex content may not convert cleanly between formats
3. Cross-origin issues: Some websites may block requests from unknown sources

Debug Mode

For additional debugging information, set the DEBUG environment variable:

DEBUG=mcp:* npm start

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Built with the Model Context Protocol
• Uses modern, actively maintained libraries with security focus
• Sanitization approach based on OWASP recommendations

Last updated: 29 March 2025