restClient.php

<?php

$client = new Zend_Http_Client();
$client->setMethod(Zend_Http_Client::POST);
$client->setUri('http://www.example.com/api/type/');
$client->setParameterPost(array(
    'useremail'  => '******@*****.***',
    'apikey'   => 'secretkey',
    'description' => 'TEST WEB API',
    'amount'   => '5000.00'
    ));
// Agregando headers
$client->setHeaders('Host: www.example.com');
$client->setHeaders('Cookie', array(
    'PHPSESSID=1234567890abcdef1234567890abcdef',
    'language=es'
));