gistfile1.php

<?php
$file_to_upload = array(
    'ticket_attachment[attachment]' => '@' . $_SERVER['DOCUMENT_ROOT'] . '/nmsworkbacklog/crown.jpg',
    'ticket_attachment[description]' => 'test description'
);
$headers = array();
$headers[] = 'Authorization: Basic ' . base64_encode('nms/martinbean:' . $this->registry->get('authenticate')->getApiKey());
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'http://api3.codebasehq.com/api-test-project/tickets/146/attachments');
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $file_to_upload);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
$result = curl_exec($ch);
echo curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close ($ch);
echo $result;