domain-mcp

An MCP (Model Context Protocol) server for domain name availability checking, WHOIS lookups, and domain suggestions — no API key required.

Uses RDAP for availability checks, real WHOIS servers via TCP port 43 for registration records, and domainr.com for domain suggestions.

Features

• Search Domains — Get domain suggestions across 25+ popular TLDs (.com, .io, .dev, .ai, etc.) with availability

• Check Domain — Detailed availability status via RDAP — registrar, creation/expiry dates, nameservers

• Bulk Check — Check up to 20 domains at once in a comparison table

• WHOIS Lookup — Full WHOIS records via TCP port 43 — registrar, registrant, dates, status, nameservers, abuse contacts

• Zero Config — No API key, no sign-up, works out of the box

Setup

1. Install & Build

cd domain-mcp
npm install
npm run build

2. Add to MCP Client

Add to your VS Code settings.json or Claude Desktop config:

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

No environment variables or API keys needed.

Tools

search_domains

Search for domain name suggestions with availability status.

check_domain

Check availability and registration details of a specific domain via RDAP.

check_multiple_domains

Bulk check multiple domains at once.

whois_lookup

Perform a WHOIS lookup via TCP port 43. Returns registrar, registrant, dates, nameservers, status flags, and abuse contacts.

How It Works

1. Domain suggestions are fetched from domainr.com (the same free web UI). Falls back to generating popular TLD combinations.

2. Availability checks use RDAP — the official, free, open replacement for WHOIS. If RDAP has no record, a DNS lookup confirms the domain doesn't exist.

3. Registration details (registrar, dates, nameservers) come from the RDAP response for registered domains.

4. WHOIS records are fetched via direct TCP connections to WHOIS servers on port 43 — the same protocol used by the whois CLI tool. Supports 45+ TLDs out of the box and auto-discovers others via IANA. Automatically follows referral servers (e.g. Verisign → registrar-specific WHOIS).

License

MIT