fourorsix: is this viewed using IPv4 or IPv6?

index.php

<?php
    // https://www.php.net/manual/en/function.str-contains.php#125977
    if (!function_exists('str_contains')) {
        function str_contains($haystack, $needle) {
            return $needle !== '' && mb_strpos($haystack, $needle) !== false;
        }
    }

    $ip = $_SERVER['REMOTE_ADDR'];
    $isipv6 = str_contains($ip, ':');
    $data = Array(
        'ip_address' => $ip,
        'ip_version' => $isipv6 ? 6 : 4
    );

    // JSON output
    header("Content-type:application/json");
    $json = json_encode($data);
    echo $json;