Throughout this chapter, we looked at the various aspects of the WordPress XML-RPC API and REST API while developing practical scenarios. In order to build stable and complex custom APIs, you should have practical experience of the preceding techniques. I recommend that you try the following tasks to extend the knowledge gathered in this chapter:

• You can measure the API usage through the number of requests.
• We created an API function to list all the forums and topics of the application. Try to introduce the filtering of results with additional parameters.
• The XML-RPC API created in this chapter returns an array as the result. Introduce different result formats such as JSON, XML, and array, so that developers can choose their preferred format.
• Implement OAuth based token authentication for REST API.