domain-rdap-mcp

Real, live domain registration lookups -- is it registered, when does it expire, who's the registrar -- free, in one command.

pip install domain-rdap-mcp   # or: uvx domain-rdap-mcp

Then ask your agent: "is example.com available?" or "when does getlulu.dev expire?"

No API key. No signup. Free.

Tools

Tool	What the model sees it for
check_domain(domain)	Check whether a domain is registered, and if so its status, registration date, expiration date, and registrar. "Is domain-x.com available?", "when does domain-x.com expire?", "who registered domain-x.com?"

Data comes from RDAP (Registration Data Access Protocol), the IETF-standardized, ICANN-mandated successor to WHOIS -- structured JSON instead of free-text, and it auto-routes to whichever registry actually holds the record.

Examples

Registered domain:

> check_domain("getlulu.dev")
{
  "domain": "getlulu.dev",
  "registered": true,
  "status": [
    "client delete prohibited",
    "client renew prohibited",
    "client transfer prohibited",
    "client update prohibited"
  ],
  "registered_date": "2025-12-16T14:20:57.819Z",
  "expiration_date": "2027-12-16T14:20:57.819Z",
  "last_changed_date": "2025-12-21T14:20:57.819Z",
  "registrar": "GoDaddy.com, LLC",
  "attribution": "Domain registration data via RDAP (rdap.org), the IETF-standardized successor to WHOIS"
}

Unregistered (available) domain:

> check_domain("zzqx9v7k2m4p8qw-nosuchdomain-xk92.com")
{
  "domain": "zzqx9v7k2m4p8qw-nosuchdomain-xk92.com",
  "registered": false,
  "attribution": "Domain registration data via RDAP (rdap.org), the IETF-standardized successor to WHOIS"
}

A 404 from RDAP means the domain isn't registered -- that's a normal, meaningful "available" answer, not an error.

Some registrars redact registrant/registrar detail for privacy; when that happens registrar comes back null rather than guessed or omitted.

How it's free

This server is part of the Lulu Ads network: tool results may carry one clearly labeled, disclosed sponsored data field (never instructions, never hidden). That sponsorship pays the hosting, so the lookup stays free. Fail-open by design -- if the ads backend is slow, down, or (as with a local install) has no credentials at all, the tools behave exactly like an unmonetized server.

Run your own MCP? The same one-line integration is open to every publisher -- getlulu.dev/publishers, 70% rev share.

Data

Domain registration data via RDAP (rdap.org), querying each domain's authoritative registry RDAP server. This project is not affiliated with ICANN, rdap.org, or any registry/registrar.

Self-hosting over HTTP

pip install fastmcp lulu-ads httpx uvicorn
MCP_TRANSPORT=http DOMAIN_LOCAL_DEV=1 python server.py   # serves http://localhost:8080/domain/mcp