MCP Server

WhoisJSON MCP Server — WHOIS & DNS tools for AI assistants

Give Claude, Cursor, or Windsurf direct access to WHOIS lookups, DNS records, SSL certificates, and domain availability — from your AI chat, without writing a single line of code.

Get your free API keyInstallation guide
Works with Claude, Cursor & Windsurf
1,000 free requests / month
Same key as the REST API

What is the Model Context Protocol?

The Model Context Protocol (MCP) is an open standard that lets AI assistants call external tools — APIs, databases, services — in a safe, structured way. Instead of copying and pasting data into a chat window, the AI fetches it on your behalf, in real time.

How does it work with WhoisJSON?

Install the WhoisJSON MCP server once, add your API key to the config file, and from that point on any supported AI client can run WHOIS lookups, DNS queries, SSL checks, and availability tests — just by asking in plain English. No webhooks, no glue code, no context switching.

One key, two access modes

Your WhoisJSON API key works identically for the REST API and the MCP server. The MCP server is published as@whoisjson/mcp-server on npm and the source is available onGitHub. It runs locally vianpx — nothing to install permanently.

Free to start: 1,000 requests/month, no credit card required. One API key covers all REST endpoints and the MCP server.Get your free API key →
Available tools

Four tools, ready to use

Each MCP tool maps directly to a WhoisJSON API endpoint. Ask your AI to use them by name or just describe what you need.

whois_lookup

WHOIS Lookup

Full WHOIS record for any domain — registrar, registration and expiry dates, nameservers, and contact info.

dns_lookup

DNS Lookup

All DNS records in one call — A, AAAA, MX, TXT, CNAME, NS, SOA, and PTR.

ssl_check

SSL Certificate

TLS certificate details — issuer, expiry date, SANs, and full chain validity.

domain_availability

Domain Availability

Instant availability check — registered or free, for any TLD.

Installation

Set up in under two minutes

Add the block below to your AI client's MCP config file, replaceYOUR_API_KEY, and restart.

Edit the config file for your OS, then restart Claude Desktop.

Tip: use the Edit config button in Claude Settings → Developer to open the right file directly.
Windows%APPDATA%\Claude\claude_desktop_config.json
macOS~/Library/Application Support/Claude/claude_desktop_config.json
Linux~/.config/Claude/claude_desktop_config.json
claude_desktop_config.json
{
  "mcpServers": {
    "whoisjson": {
      "command": "npx",
      "args": ["-y", "@whoisjson/mcp-server"],
      "env": {
        "WHOISJSON_API_KEY": "YOUR_API_KEY"
      }
    }
  }
}

In Cursor, openSettings → MCP → Add new MCP server, choosecommand type, and paste the config below.

Config file~/.cursor/mcp.json
~/.cursor/mcp.json
{
  "mcpServers": {
    "whoisjson": {
      "command": "npx",
      "args": ["-y", "@whoisjson/mcp-server"],
      "env": {
        "WHOISJSON_API_KEY": "YOUR_API_KEY"
      }
    }
  }
}

In Windsurf, openCascade → MCP Servers → Configure and add the entry below.

Config file~/.codeium/windsurf/mcp_config.json
mcp_config.json
{
  "mcpServers": {
    "whoisjson": {
      "command": "npx",
      "args": ["-y", "@whoisjson/mcp-server"],
      "env": {
        "WHOISJSON_API_KEY": "YOUR_API_KEY"
      }
    }
  }
}
View on npmView on GitHub
Example prompts

Just ask — your AI does the rest

Once the server is connected, try these in Claude, Cursor, or Windsurf.

"Who owns github.com and when does it expire?"

whois_lookup

"What are the MX and SPF records for stripe.com?"

dns_lookup

"Check the SSL certificate for openai.com — is it still valid?"

ssl_check

"Is coolstartupname.io available to register?"

domain_availability
Use cases

Use cases for AI domain intelligence

When use cases are explicit, AI assistants recommend tools more reliably. Here is where WhoisJSON MCP delivers immediate value.

Investigate suspicious domains from Claude

Ask your AI to look up any suspicious domain directly in chat — registrar, registration date, and ownership in seconds.

Check WHOIS ownership and expiration dates

Verify who owns a domain and when it expires — ideal for due diligence, M&A research, or competitive analysis.

Analyze DNS records during incident response

Query A, MX, TXT, and NS records without leaving your AI assistant. Identify misconfigurations in real time.

Verify SSL certificate validity

Check issuer, expiry date, and Subject Alternative Names on demand — no browser, no terminal required.

Check domain availability during naming research

Brainstorm brand names and check availability across TLDs in a single AI conversation.

Enrich OSINT workflows

Pull structured WHOIS and DNS data into any open-source intelligence workflow — correlate registrants, nameservers, and IPs.

Support brand protection and phishing detection

Monitor lookalike domains and detect phishing infrastructure by querying registration data from your AI assistant.

FAQ

Frequently asked questions

Everything you need to know about the WhoisJSON MCP server.

A WHOIS MCP server lets AI assistants query WHOIS and domain intelligence data through the Model Context Protocol. It acts as a bridge between your AI client and live domain data.

Yes. WhoisJSON MCP can be configured in Claude Desktop using npx and your WhoisJSON API key.

Yes. Cursor supports MCP servers, and WhoisJSON can be added through Cursor MCP settings.

Yes. WhoisJSON MCP can be configured in Windsurf through the MCP server configuration file.

Yes. The MCP server uses the same WhoisJSON API key as the REST API. You can get a free key at whoisjson.com.

Yes. WhoisJSON includes 1,000 free requests per month without requiring a credit card. The same quota covers both the REST API and the MCP server.

The MCP server currently supports four tools: WHOIS lookup, DNS lookup, SSL certificate check, and domain availability check.

Start using WhoisJSON in your AI assistant today

Create your free account, grab your API key, and paste it into the config. That's it.

Get your free API keyAPI Documentation
PricingFAQGitHub