If you are utilizing Magento’s API and have checked out the documentation, you’ll see that they have included a V2 of their soap API saying:
As of v1.3 you may also use http://yourmagentohost/api/v2_soap?wsdl=1 which has been added to improve compatbility with Java and .NET.
If you find the need to utilize the v2_soap API, take note that you will need to call your methods differently than the documentation explains.
For example, if you would like to use the sales_order.info method, using the standard soap API, you would do the following to get all the order info for order number 1000000142:
$client = new SoapClient('http://yourwebsite.com/api/soap/?wsdl'); $session = $client->login('username', 'password'); $result = $client->call($session, 'sales_order.info', '1000000142');
If you need to use the V2 API, you need to so it slightly different. Instead of using the call() method, you call the specific API method instead:
$client = new SoapClient('http://yourwebsite.com/api/soap/?wsdl'); $session = $client->login('username', 'password'); $result = $client->salesOrderInfo($session, '1000000142');
So, for V2, you must convert the method names in the Magento documentation to a camel-case method name.