Give this API up to 10 domain names and it tells you whether each has a registration record at the official registry. It uses RDAP, the structured replacement for WHOIS, so there is no free-text parsing. Each domain comes back as 'registered', 'unregistered', or 'indeterminate' when the registry has no RDAP for that ending. 'Unregistered' means no record was found, which usually means available - but reserved and premium names also return no record. Registration status only; no pricing.