We started this chapter with the intention of building an XML-RPC-based API for web applications. Then, we discussed the usage of the existing API functions while building an API client from scratch.

Complex applications will always exceed the limits of an existing API, hence, we looked at the possibility of creating a custom API. User authentication and API tokens were necessary for preventing unnecessary API access and measuring the API usage. Finally, we looked at the possibility of creating the API documentation through another API function. Having completed the API creation techniques, you should now be able to develop complex APIs to suit any kind of web application.

In the next chapter, we will be restructuring our application plugin to improve consistency of code, while looking at some of the incomplete areas of the portfolio management application. So, be prepared for an exciting finish to this book!