ip.rbn.gr — what is my IP

Two choices: which fields, and what shape.

Fields    ?fields=ip,rdns   or  /ip,rdns     default: ip family scope public
          ?fields=all       or  /all
Format    ?format=json      or  /json        default: text, html for browsers

Examples:
  curl -s https://ip.rbn.gr
  curl -s https://ip.rbn.gr/json
  curl -s https://ip.rbn.gr/json/all/pretty
  curl -s https://ip.rbn.gr/rdns
  curl -s https://ip.rbn.gr/ip,family,scope
  eval "$(curl -s https://ip.rbn.gr/sh)"
  curl -4 -s https://ipv4.rbn.gr
  curl -6 -s https://ipv6.rbn.gr

Formats (the format has to be the FIRST path segment):
  text   one value per line (just the IP when no fields are named)
  json   object, keys in the order you asked for
  sh     shell exports, safe for eval; errors are comments plus `false`
  html   browser page
  help   this text

Fields:
  ip family scope public rdns rdns_verified
  rdns and rdns_verified cost a DNS lookup, so they are never in the default
  set, and they are resolved fresh on every request — no cache, no rate limit.

Modifiers (query params, or extra path segments):
  pretty  pretty-printed JSON
  strict  404 instead of an empty body when nothing you asked for has a value
  cors    Access-Control-Allow-Origin: *

Scopes — public is true only for global:
  global this-network private cgnat loopback link-local site-local ula
  multicast broadcast unspecified documentation benchmarking reserved
  teredo 6to4 nat64 as112 amt srv6 discard ipv4-mapped

rdns_verified is forward-confirmed rDNS: the PTR name was resolved back
and it points at this address. false means the name is unverified, null
means there is no PTR record at all.

The HTML page is a fixed, minimal view (address, rdns, rdns_verified, one
row per family) and ignores ?fields=/path fields entirely — that selection
is a curl-only feature. The page always resolves both, for both address
families; a plain curl request never pays for that unless it names the
fields itself.