Neat. You could drop the HTTP part and use pure DNS: $ dig @auth-ns hashed-password.andy.tel naptr NXDOMAIN on failure, NAPTR record (or a set of records) on

Neat. You could drop the HTTP part and use pure DNS: $ dig @auth-ns hashed-password.andy.tel naptr NXDOMAIN on failure, NAPTR record (or a set of records) on success. Your comment about DNS being an API is right on.