index.php

<?php
include('database.php');

/**
 * Encrypt your proxy through the 9Hits API
 *
 * This method encrypts your proxy to protected it.
 *
 * @param  proxy|array of proxy information
 *
 * @return object
 */
function encryptProxy($proxy) {
    $url = 'http://proxy.9hits.com/we/encrypt-proxy?input='.urlencode(base64_encode(json_encode($proxy)));
    $result = json_decode(file_get_contents($url));
    return $result;
}

// Your code to get one proxy from your database or any source.
// Make sure your source code returns a unique proxy
// ......

/*$proxy = [
    'type' => 'http',               //must be one of ["socks4", "socks5", "http", "ssh"]
    'server' => '156.54.219.109:8080',   //required
    'user' => '',             //optional
    'password' => ''         //optional
];*/

$sql = $db->query("SELECT * FROM `proxy` ORDER BY RAND() LIMIT 1");
$data = $sql->fetch_assoc();
$proxy = [
	'type' => $data['type'],
	'server' => $data['server'],
	'user' => $data['user'],
	'password' => $data['password']
];
$result = encryptProxy($proxy);
/*
The result should be an object like this
{
    "status": "ok|error",
    "message": "Message from the 9Hits server",
    "input": your input,
    "output": Encrypted proxy
}
*/
echo $result->output;
?>