ASN Lookup

RDAP

Find the autonomous system (AS number, name and BGP prefix) announcing an IP — resolved over Team Cymru DNS, no whois API.

Use this from the command line

curl -s https://ipcow.com/api/tools/asn-lookup \
  -H 'content-type: application/json' \
  -d '{"ip":"9.9.9.9"}'