🔍 WHOIS MCP Server

中文版 | English

A comprehensive MCP server for WHOIS lookups of domains, IPs, TLDs, and ASNs

🎯 Overview

A Model Context Protocol (MCP) server that provides WHOIS lookup capabilities for domains, IP addresses, Top Level Domains (TLDs), and Autonomous System Numbers (ASNs). Built with TypeScript and the whoiser library for reliable and fast WHOIS queries.

✨ Features

• 🌐 Domain WHOIS: Look up registration information for any domain
• 🖥️ IP WHOIS: Get network information and ownership details for IP addresses
• 🏷️ TLD WHOIS: Retrieve information about Top Level Domains
• 🔢 ASN WHOIS: Look up Autonomous System Number details
• 🔒 Type Safety: Full TypeScript implementation with Zod validation
• 🎨 Colorful Logging: Colored console output for better visibility
• ⚡ Fast Performance: Built on the reliable whoiser library
• 🛡️ Error Handling: Comprehensive error handling with friendly messages

📦 Installation

npm install @szemeng76/whois-mcp

Or clone and install locally:

git clone https://github.com/SzeMeng76/whois-mcp.git
cd whois-mcp
npm install
npm run build

🔧 Configuration

Claude Desktop

{
  "mcpServers": {
    "whois": {
      "command": "npx",
      "args": ["@szemeng76/whois-mcp@latest"]
    }
  }
}

Cursor IDE

{
  "mcpServers": {
    "whois": {
      "command": "npx",
      "args": ["@szemeng76/whois-mcp@latest"]
    }
  }
}

VS Code with GitHub Copilot

{
  "mcp.servers": {
    "whois": {
      "command": "npx",
      "args": ["@szemeng76/whois-mcp@latest"],
      "transport": "stdio"
    }
  }
}

Local Development

{
  "mcpServers": {
    "whois": {
      "command": "node",
      "args": ["path/to/whois-mcp/dist/index.js"]
    }
  }
}

🛠️ Available Tools

whois_domain

Looks up WHOIS information for a domain name.

Parameters:

• domain (required): Domain name to query (e.g., "example.com", "github.com")

Example Usage:

"Look up WHOIS information for google.com"
"Get domain registration details for stackoverflow.com"
"Check who owns the domain github.com"

Returns:

• Domain registration information
• Registrar details
• Name servers
• Creation and expiration dates
• Registrant contact information (if available)

whois_ip

Looks up WHOIS information for an IP address.

Parameters:

• ip (required): IPv4 or IPv6 address to query (e.g., "8.8.8.8", "1.1.1.1")

Example Usage:

"Get WHOIS information for IP address 8.8.8.8"
"Look up the owner of IP 1.1.1.1" 
"Check network details for 192.168.1.1"

Returns:

• Network ownership information
• IP address range allocation
• Organization details
• Geographic location data
• Contact information

whois_tld

Looks up WHOIS information for a Top Level Domain.

Parameters:

• tld (required): Top Level Domain to query (e.g., "com", "org", "io")

Example Usage:

"Get information about the .com TLD"
"Look up details for the .io domain"
"Check who manages the .org TLD"

Returns:

• TLD registry information
• Managing organization
• Policy details
• Contact information
• Technical details

whois_as

Looks up WHOIS information for an Autonomous System Number.

Parameters:

• asn (required): ASN in format "AS####" (e.g., "AS15169", "AS13335")

Example Usage:

"Look up ASN AS15169"
"Get information about AS13335"
"Check details for autonomous system AS8075"

Returns:

• ASN ownership information
• Organization details
• Network routes
• Contact information
• Technical details

🎮 Usage Examples

Security Research

"Look up the domain suspicious-site.com to check its registration details"
"Get WHOIS info for IP 203.0.113.1 to identify the network owner"

Network Troubleshooting

"Check ASN AS15169 to see what networks Google operates"
"Look up IP 1.1.1.1 to verify it belongs to Cloudflare"

Domain Investigation

"Get registration details for example.com to see when it expires"
"Look up .io TLD information to understand the registry policies"

Competitive Analysis

"Check WHOIS for competitor-domain.com to see registration patterns"
"Look up multiple domains: example1.com, example2.org, example3.net"

🏗️ Development

Local Setup

# Clone the repository
git clone https://github.com/SzeMeng76/whois-mcp.git
cd whois-mcp

# Install dependencies
npm install

# Build the project
npm run build

# Start the server
npm start

Project Structure

whois-mcp/
├── src/
│   ├── index.ts          # Main MCP server implementation
│   └── utils.ts          # Utility functions (colored console output)
├── dist/                 # Compiled JavaScript files
├── package.json          # Dependencies and scripts
├── tsconfig.json         # TypeScript configuration
└── README.md            # Documentation

Core Dependencies

• @modelcontextprotocol/sdk: Official MCP server framework
• whoiser: Reliable WHOIS lookup library
• zod: Runtime type validation and schema definition

🔧 Technical Details

Input Validation

• Domain names: Basic non-empty string validation
• IP addresses: Basic non-empty string validation (library handles format validation)
• TLDs: Non-empty string validation
• ASNs: Regex validation for "AS####" format with automatic number conversion

Error Handling

• Comprehensive try-catch blocks for all WHOIS operations
• Friendly error messages for common issues
• Graceful handling of network timeouts and invalid inputs
• Error responses include isError: true flag

Logging and Output

• Colored console output using custom utility functions
• Green checkmark for successful startup
• Yellow warnings for shutdown procedures
• Red error messages for failures
• Structured JSON responses for all WHOIS data

Signal Handling

• Graceful shutdown on SIGINT (Ctrl+C) and SIGTERM
• Proper cleanup of transport connections
• User-friendly shutdown messages

⚠️ Important Notes

Rate Limiting

• WHOIS servers have rate limits to prevent abuse
• Avoid making too many rapid consecutive queries
• Some servers may temporarily block excessive requests

Data Accuracy

• WHOIS data accuracy depends on registrar compliance
• Some domains may have privacy protection enabled
• Historical data may not always be available

Legal Considerations

• WHOIS data is subject to various privacy laws and regulations
• Use data responsibly and in compliance with applicable laws
• Respect registrar terms of service and rate limits

🚀 Common Use Cases

Cybersecurity

• Threat Intelligence: Investigate suspicious domains and IP addresses
• Incident Response: Gather information about malicious infrastructure
• Domain Monitoring: Track domain registration changes

Network Administration

• IP Management: Verify IP address ownership and allocation
• Routing Analysis: Understand ASN relationships and network paths
• Infrastructure Planning: Research network providers and ASN details

Business Intelligence

• Competitive Research: Monitor competitor domain registrations
• Due Diligence: Verify domain ownership before partnerships
• Brand Protection: Monitor similar domain registrations

Development and Testing

• API Integration: Test WHOIS functionality in applications
• Network Debugging: Troubleshoot connectivity and routing issues
• Educational Purposes: Learn about internet infrastructure

🤝 Contributing

1. Fork the repository
2. Create a feature branch: git checkout -b feature-name
3. Make your changes with proper TypeScript types
4. Test with various domains, IPs, TLDs, and ASNs
5. Ensure error handling works correctly
6. Submit a pull request with clear description

Development Guidelines

• Maintain TypeScript strict mode compliance
• Add proper error handling for new features
• Use the existing color utility functions for console output
• Test with both valid and invalid inputs
• Document any new parameters or return formats

📄 License

MIT License - see LICENSE file for details.

⚖️ Legal and Privacy

• Data Source: WHOIS data is retrieved from public registries
• Privacy: Some WHOIS data may be redacted due to privacy policies
• Compliance: Users must comply with applicable privacy laws and regulations
• Rate Limits: Respect WHOIS server rate limits and terms of service
• Responsible Use: Use WHOIS data for legitimate purposes only

🙏 Acknowledgments

• whoiser: Excellent WHOIS lookup library
• MCP Community: For the standardized protocol
• Internet Registries: For maintaining public WHOIS services
• Contributors: Everyone who helps improve this project

Built for network research, security analysis, and internet infrastructure understanding 🔍🌐