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WhoisJSON

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WHOIS, DNS, SSL, and domain availability lookups for AI assistants

Source code Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

NPM package @whoisjson/mcp-server
Claude Code 
claude mcp add whoisjson -e 'WHOISJSON_API_KEY=<your whoisjson_api_key>' -- npx -y @whoisjson/mcp-server@1.0.3
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "whoisjson": {
            "command": "npx",
            "args": [
                "-y",
                "@whoisjson/mcp-server@1.0.3"
            ],
            "env": {
                "WHOISJSON_API_KEY": "<your whoisjson_api_key>"
            }
        }
    }
}

Environment variables

  • WHOISJSON_API_KEY required secret Your WhoisJSON API key from whoisjson.com/dashboard

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. @whoisjson/mcp-server
  2. Tools
  3. Prerequisites
  4. Installation
  5. Configuration
  6. Running locally (development)
  7. Publishing
  8. API reference

@whoisjson/mcp-server

MCP (Model Context Protocol) server for the WhoisJSON API. Exposes WHOIS, DNS, SSL, and domain availability lookups as tools for AI assistants.

Tools

ToolDescription
whois_lookupWHOIS registration data for a domain (registrar, dates, contacts, nameservers…)
dns_lookupAll DNS records for a domain (A, AAAA, MX, NS, TXT, CNAME, SOA, CAA, DMARC…)
ssl_checkSSL/TLS certificate details and validity for a domain
domain_availabilityCheck if a domain is available for registration

Prerequisites

  1. Sign up at whoisjson.com and copy your API key from the dashboard.
  2. Node.js ≥ 18.

Installation

npm install -g @whoisjson/mcp-server
# or run directly with npx (no install needed):
npx @whoisjson/mcp-server

Configuration

Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or
%APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "whoisjson": {
      "command": "npx",
      "args": ["-y", "@whoisjson/mcp-server"],
      "env": {
        "WHOISJSON_API_KEY": "your_api_key_here"
      }
    }
  }
}
Cursor

Edit ~/.cursor/mcp.json:

{
  "mcpServers": {
    "whoisjson": {
      "command": "npx",
      "args": ["-y", "@whoisjson/mcp-server"],
      "env": {
        "WHOISJSON_API_KEY": "your_api_key_here"
      }
    }
  }
}
Windsurf

Edit ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "whoisjson": {
      "command": "npx",
      "args": ["-y", "@whoisjson/mcp-server"],
      "env": {
        "WHOISJSON_API_KEY": "your_api_key_here"
      }
    }
  }
}

Running locally (development)

cd mcp-server
npm install
npm run build
WHOISJSON_API_KEY=your_key npm start

Publishing

npm run build
npm publish --access public

API reference

Full API documentation: whoisjson.com/documentation

Frequently asked questions

What is WhoisJSON?

WHOIS, DNS, SSL, and domain availability lookups for AI assistants

How do I install WhoisJSON?

It runs on your machine. In Claude Code: claude mcp add whoisjson -e 'WHOISJSON_API_KEY=<your whoisjson_api_key>' -- npx -y @whoisjson/mcp-server@1.0.3. For other clients, paste the JSON configuration from this page into their MCP settings.

Does WhoisJSON need an API key?

Yes. It expects WHOISJSON_API_KEY, which you set in its configuration.

Is WhoisJSON open source?

Its code is public on GitHub, but the repository does not declare a standard license.

Who maintains WhoisJSON?

It is published by Whoisjson. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.