From WHMCS Documentation
Communicating with the WHMCS API is very simple. The sample PHP code below is how we recommend interfacing with it.
<?php
$url = "http://www.yourdomain.com/whmcs/includes/api.php"; # URL to WHMCS API file
$username = "Admin"; # Admin username goes here
$password = "demo"; # Admin password goes here
$postfields["username"] = $username;
$postfields["password"] = md5($password);
$postfields["action"] = "addinvoicepayment";
$postfields["invoiceid"] = "1";
$postfields["transid"] = "TEST";
$postfields["gateway"] = "mailin";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 100);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $postfields);
$data = curl_exec($ch);
curl_close($ch);
$data = explode(";",$data);
foreach ($data AS $temp) {
$temp = explode("=",$temp);
$results[$temp[0]] = $temp[1];
}
if ($results["result"]=="success") {
# Result was OK!
} else {
# An error occured
echo "The following error occured: ".$results["message"];
}
?>
