MCP Server Integration

WhoisFreaks MCP Server

A Model Context Protocol (MCP) server that exposes the full WhoisFreaks API suite as AI-callable tools. Works with Claude Desktop, Cursor, Windsurf, VS Code, Continue, Zed, and any other MCP-compatible AI client.

How to Install?

Two ways to run it - pick what fits your setup:

Method	Requires	Best for
Docker (pre-built image)	Docker only	Everyone — no Java or Maven neededRecommended
Build from source	Java 17 + Maven	Contributors / custom builds

ⓘ Tip

Once running, connect it to any MCP client via stdio (local) or HTTP/SSE on port 3100 (remote VM).

Tools Reference

The WHOIS Domain API delivers structured JSON or XML data with registry and registrar details when available. It organizes ownership information into separate objects like registrant, technical, billing, and administrative details alongside nameservers and key domain dates such as registration and expiry. The WHOIS Domain API’s structured format ensures seamless integration into your systems.

WHOIS Tools

Tool	Description
liveWhoisLookup	Real-time WHOIS data for any domain — registrar, registrant, dates, nameservers
whoisHistory	Complete ownership history timeline for a domain
reverseWhoisLookup	Find all domains registered by an email address, keyword, owner name, or company

IP & ASN WHOIS Tools

Tool	Description
ipWhoisLookup	WHOIS registration data for any IPv4 or IPv6 address
asnWhoisLookup	WHOIS data for an Autonomous System Number (e.g. AS15169)

DNS Tools

Tool	Description
dnsLookup	Live DNS records - A, AAAA, MX, NS, CNAME, SOA, TXT, SPF, or all
dnsHistory	Historical DNS records with full change timeline
reverseDnsLookup	Find all domains pointing to a given IP or nameserver

IP Intelligence Tools

Tool	Description
ipGeolocation	Country, city, region, ISP, and coordinates for any IP address
ipSecurity	VPN, proxy, Tor exit node, bot, and threat intelligence for any IP

Domain Tools

Tool	Description
domainAvailability	Check if a domain is available to register, with optional suggestions
subdomainLookup	Enumerate all known subdomains for a domain, with status and date filters
domainDiscovery	Find domains by keyword, including typosquatting and similar variants

SSL Tools

Tool	Description
sslLookup	SSL/TLS certificate details - issuer, expiry, SANs, chain, and raw output

Quick Start

Docker

Recommended

No Java or Maven required. Pull the pre-built image directly from Docker Hub and run.

Get your free API key first: whoisfreaks.com/signup

Option 1 — Direct docker run (simplest)

docker run -d   --name whoisfreaks-mcp   --restart unless-stopped   -p 3100:3100   -e WHOISFREAKS_API_KEY=your-api-key-here   whoisfreaks/mcp-server:latest

The MCP gateway is now live at http://localhost:3100/sse.

Option 2 — Docker Compose (recommended for production / VM)

Create a docker-compose.yml

services:
  whoisfreaks-mcp:
    image: whoisfreaks/mcp-server:latest
    container_name: whoisfreaks-mcp
    restart: unless-stopped
    ports:
      - "3100:3100"
    environment:
      WHOISFREAKS_API_KEY: your-api-key-here

Start it:

docker compose up -d

Or use a .env file instead of hardcoding the key (recommended):

# Create .env file (never commit this to git)
echo "WHOISFREAKS_API_KEY=your-api-key-here" > .env
docker compose up -d

Verify Docker is working

# Container should show as "Up"
docker ps

# SSE endpoint should respond
curl http://localhost:3100/health
# → {"status":"ok"}

# List all 14 registered tools
curl http://localhost:3100/tools/list

Use with Claude Desktop (Docker stdio mode)

Claude Desktop requires stdio transport. Override the Docker entrypoint to bypassmcp-proxy and run the JAR directly:

{
  "mcpServers": {
    "whoisfreaks": {
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "-e", "WHOISFREAKS_API_KEY=your-api-key-here",
        "--entrypoint", "java",
        "whoisfreaks/mcp-server:latest",
        "-jar", "app.jar"
      ]
    }
  }
}

Build from Source

Only needed if you want to modify the code or build a custom version.

Prerequisites:

Requirement	Minimum Version	Notes
Java (JDK)	17	Check with`java -version`
Maven	3.8	Check with`mvn -version`
WhoisFreaks API Key	—	Get yours at whoisfreaks.com/signup

Clone and build:

git clone https://github.com/whoisfreaks/whoisfreaks-mcp-server.git
cd whoisfreaks-mcp-server
mvn clean package -q

This produces a single self-contained fat JAR:

target/whoisfreaks-mcp-server-1.0.0.jar

ⓘ Tip

Note the absolute path to this JAR — you will need it in the platform configs below. Example:

/Users/yourname/whoisfreaks-mcp-server/target/whoisfreaks-mcp-server-1.0.0.jar

Platform Integration

1. Claude Desktop

The most popular MCP client. Claude Desktop launches the MCP server as a subprocess on startup and communicates via stdio - it does not support SSE/HTTP URLs.

Config file location:

OS	Path
macOS	`~/Library/Application Support/Claude/claude_desktop_config.json`
Windows	`%APPDATA%Claudeclaude_desktop_config.json`
Linux	`~/.config/Claude/claude_desktop_config.json`

Option A — JAR directly (requires Java 17)

{
  "mcpServers": {
    "whoisfreaks": {
      "command": "java",
      "args": ["-jar", "/absolute/path/to/whoisfreaks-mcp-server-1.0.0.jar"],
      "env": {
        "WHOISFREAKS_API_KEY": "your-api-key-here"
      }
    }
  }
}

Steps (both options):

Paste the config above into the config file (create it if it doesn't exist)
Save the file
Quit Claude Desktop completely (Cmd+Q on macOS / taskbar exit on Windows)
Reopen Claude Desktop
Click the hammer icon (Tools) in the chat input — you should see 14 WhoisFreaks tools listed

Verify it works: Type Who owns google.com? and Claude will automatically callliveWhoisLookup.

Example Prompts

Once configured in any client above, try these prompts:

# WHOIS
Who owns the domain apple.com? Give me full WHOIS details.
Show me the complete ownership history for whoisfreaks.com.
Find all domains registered by [email protected].

# IP & ASN WHOIS
What organization owns the IP address 8.8.8.8?
Look up ASN information for AS15169.

# DNS
What are the MX and NS records for github.com?
Has facebook.com changed its IP addresses in the last 2 years? (DNS history)
Which domains are pointing to the IP 104.21.0.0? (reverse DNS)

# IP Intelligence
Where is 1.1.1.1 located? What ISP runs it?
Is 185.220.101.45 a Tor exit node or a VPN?

# Domain Tools
Is mycompany.io available to register? Suggest 5 alternatives.
List all known subdomains of tesla.com.
Find domains similar to 'google' — possible typosquatting targets.

# SSL
Check the SSL certificate for github.com — who issued it and when does it expire?

Environment Variables

Variable	Required	Description
`WHOISFREAKS_API_KEY`	Yes	Your API key from whoisfreaks.com/billing. All 14 tools call`api.whoisfreaks.com`directly using this key — no other variables are needed.

Troubleshooting

API Errors

Problem	Cause	Fix
`WHOISFREAKS_API_KEY is not set`	Missing env var	Add`-e WHOISFREAKS_API_KEY=your-key`to the Docker command, or add it to the`env`block in your client config
`Unauthorized (HTTP 401/403)`	Invalid or inactive API key	Verify the key at billing.whoisfreaks.com
`No data found (HTTP 404)`	Domain/IP/ASN not in database	Double-check the input value is correct
`Rate limit reached (HTTP 429)`	Too many requests	Slow down or upgrade your plan
`Credit limit exceeded (HTTP 413)`	Credits exhausted	Add credits at billing.whoisfreaks.com
`Timeout (HTTP 408)`	Upstream WHOIS server is slow	Retry - some TLDs have slow WHOIS servers

Docker Errors

Problem	Cause	Fix
`Cannot connect to Docker daemon`	Docker Desktop not running	Open Docker Desktop and wait for the engine to start
Container exits immediately	Missing API key or wrong entrypoint	Check logs:`docker logs whoisfreaks-mcp`
`port 3100 already in use`	Another process on port 3100	Stop it:`docker rm -f whoisfreaks-mcp`then retry
`no such image`	Image not pulled yet	Run`docker pull whoisfreaks/mcp-server:latest`first
Claude Desktop: tools not appearing with Docker config	Docker not in PATH seen by the app	Use the full Docker path:`/usr/local/bin/docker`as the command
`lstat deploy: no such file or directory`(CI/CD)	Relative path issue in GitHub Actions	Use`${{ github.workspace }}/deploy/Dockerfile`for absolute paths
`Gateway connection refused on port 3100`	Container not running or port not mapped	Run `docker ps`- ensure`-p 3100:3100`is in the run command
SSE connection drops after a few seconds	Nginx proxy timeout	Add`proxy_read_timeout 3600s;`to your Nginx location block

Client Errors

Problem	Cause	Fix
Tools not visible in client	Config not saved or client not restarted	Save config → fully quit and reopen the client
`UnsupportedClassVersionError`(JAR mode)	Java version too old	Upgrade to Java 17+ (java -version to check)
Wrong JAR path	Relative path in config	Use the full absolute path to the JAR
Cursor shows tools but doesn't call them	Agent mode not enabled	Switch Cursor to Agent mode, not Chat mode
Claude Desktop skips whoisfreaks entry	SSE URL used instead of stdio	Claude Desktop requires`command/args`- not url. Use the Docker stdio config shown above
Windsurf tools not called	Wrong Cascade mode	Switch Cascade to Write mode from the Cascade header