WebHook API :Unlimited SMS Using Android Mobile

define("API_KEY", "Your API KEY");

try {
    if (isset($_SERVER["HTTP_X_SG_SIGNATURE"])) {
        if (isset($_POST["messages"])) {
            $hash = base64_encode(hash_hmac('sha256', $_POST["messages"], API_KEY, true));
            if ($hash === $_SERVER["HTTP_X_SG_SIGNATURE"]) {
                $messages = json_decode($_POST["messages"], true);
    
                /**
                 * For example :-
                 * $messages = [
                 *                 0 => [
                 *                          "ID" => "1",
                 *                          "number" => "+11234567890",
                 *                          "message" => "This is a test message.",
                 *                          "deviceID" => "1",
                 *                          "simSlot" => "0",
                 *                          "userID" => "1",
                 *                          "status" => "Received",
                 *                          "sentDate" => "2018-10-20T00:00:00+02:00",
                 *                          "deliveredDate" => "2018-10-20T00:00:00+02:00"
                 *                          "groupID" => null
                 *                      ]
                 *             ]
                 *
                 * senDate represents the date and time when the message was received on the device.
                 * deliveredDate represents the date and time when the message was received by the server.
                 */
    
                foreach ($messages as $message) {
                    if(strtolower($message["message"]) === "hi") {
                        // Reply to message using API or execute some commands. Possibilities are limitless.
                    }
                }
            } else {
                throw new Exception("Signature don't match!");
            }
        } else if (isset($_POST["ussdRequest"])) {
            $hash = base64_encode(hash_hmac('sha256', $_POST["ussdRequest"], API_KEY, true));
            if ($hash === $_SERVER["HTTP_X_SG_SIGNATURE"]) {
                $ussdRequest = json_decode($_POST["ussdRequest"]);
                $deviceID = $ussdRequest->deviceID;
                $simSlot = $ussdRequest->simSlot;
                $request = $ussdRequest->request;
                $response = $ussdRequest->response;
                
                // Do whatever you want with data you received.
            } else {
                throw new Exception("Signature don't match!");
            }
        }
    } else {
        http_response_code(400);
        error_log("Signature not found!");
    }
} catch (Exception $e) {
    http_response_code(401);
    error_log($e->getMessage());
}