| name | domain-whois |
| description | Look up domain registration info, expiry dates, and registrar details. |
Domain WHOIS
Look up domain registration info, expiry dates, and registrar details.
Category: security
API Key Required: No
When to use
- User asks "who owns this domain?"
- User wants to check if a domain is registered
- User asks about domain expiry or registrar info
- User wants DNS or nameserver info for a domain
How it works
Option 1: RDAP (modern WHOIS, free, no key)
RDAP is the official successor to WHOIS. Query the Verisign RDAP server directly for .com/.net domains:
curl -s "https://rdap.verisign.com/com/v1/domain/example.com"
curl -s "https://rdap.verisign.com/net/v1/domain/example.net"
curl -s "https://rdap.org/domain/example.org"
Returns JSON with: registration dates, expiry, registrar, nameservers, status codes.
Key fields:
events[] — registration, expiration, last changed dates
entities[] — registrar info
nameservers[] — DNS servers
status[] — domain status flags
Option 2: Command-line whois
whois example.com
Option 3: ip-api for IP-based lookups
curl -s "http://ip-api.com/json/example.com"
Examples
User: "Who owns google.com?"
→ Query RDAP. Reply with registrar, registration date, expiry date, nameservers.
User: "When does example.com expire?"
→ Query RDAP, find the expiration event. Reply with the date.
User: "Is coolstartup.io taken?"
→ Query RDAP. If registered, show details. If not found, tell user it may be available.
Constraints
- RDAP coverage varies by TLD — most gTLDs (.com, .net, .org) are well supported
- Some ccTLDs may not have RDAP servers yet
- Privacy/proxy registrations will hide owner details
- Rate limits vary by registry (be reasonable, ~1 req/sec)