Domain WHOIS/RDAP lookup API: registration data for any domain from the authoritative registry's RDAP server, normalized: registration/expiry/update dates, registrar, EPP status codes, nameservers, and DNSSEC. Works for all gTLDs and most ccTLDs. Unregistered or RDAP-less domains return an unpaid 404. Use for domain availability checks, ownership research, expiry monitoring, and security screening by agents. Cached up to 24 hours.