Welcome to the Reference Guide. In here you'll find in-depth documentation about the JavaScript APIs surrounding our entire Apps framework.
If you're going to be developing Apps with Zendesk, then you're looking in the right place. First though, please take a good read through our Getting Started Guide which will take you through the fundamentals, as well as using a working example to guide you through Apps from the ground up.
The reference guide is a complete collection of every API available to your as a Zendesk apps developer. While we do recommend reading over the entire reference guide, unlike the Getting Started Guide you do not need to understand each method we present - only those you intend to use.
There's no particular order you need to read the Reference Guide in, but why not start at the beginning.