NetTuts.com has posted the second part of their series showing how to create a custom API in Magento. In part one of the series they focused on creating a custom module that worked with the core APIs and system. In this new post they approach it from the other side and show how to use those APIs created in part one.
In this series, we're discussing custom APIs in Magento. In the first part, we created a full-fledged custom module to implement the custom API, in which we created the required files to plug in the custom APIs provided by our module. In this second and last part, we'll go through the back-end section to demonstrate how to consume the APIs.
They start with a quick recap of the things created in the first part of the series and how to ensure it's set up correctly to be accessed as an API endpoint. Next they set up the user and role configurations that you'll need to access the new API through the administration panel. Finally, they show you how to use the API through a simple SoapClient request.