magentoapi | Magento SOAP API Wrapper | SOAP library

The short story is - I need a way for a single code base to be able to connect to multiple SOAP APIs where each API's WSDL is essentially the same except that the XML Namespace varies site by site.

The long story is (sorry there is a lot of this):

My .NET 4.5 application acts as a client to the Magento SOAP API (downloads orders, uploads products, stock levels etc). The application uses a Service Reference to a stock Magento WSDL, and for Magento 1.x this worked fine - the application could connect to any website's Magento API just by passing a different endpoint URL when instantiating the client.

So then Magento 2 came along, and I wanted to make a new version of the application that could interface with it. However a significant challenge arose.

I started by creating a Service Reference to a known Magento 2 website API's WSDL (this was not straightforward as under Magento 2 the WSDL is only exposed if the request is OAUTH authenticated, but that is another story). The application worked fine when connecting to that same website API. However when any other endpoint URL is used to instantiate the client, every method call seems to result in a null response object. If the Service Reference is re-created from the target website's WSDL, then it starts working. Obviously I cannot do this and compile a new version of the application for every different possible target website!

I looked at the difference between my reference WSDL and another, and traced the request and response with Fiddler, and I noticed something that I believe to be the root cause of the problem. Unlike under Magento 1.x, a Magento 2 WSDL has XML Namespaces specific to the website the WSDL came from. This translates to different Namespace values in class attributes in the Reference.cs of the Service Reference, for example:

Magento 1.x attributes (note the generic Namespace value):