HipChat API message with HTML

gistfile1.php

<?php

// HipChat PHP library: https://github.com/hipchat/hipchat-php
include 'HipChat.php';

$token = "<your token>";
$room = "Development";
$message = 'Some <b>html</b>, &lt;entities&gt;, and a <a href="https://www.hipchat.com">link</a>.<br />We can even use line breaks!';

$hc = new HipChat($token);
$hc->message_room($room, 'API Test', $message);