This document offers a basic understanding of the REST API used by automation controller.
REST stands for Representational State Transfer and is sometimes spelled as "ReST". It relies on a stateless, client-server, and cacheable communications protocol, usually the HTTP protocol.
You may find it helpful to see which API calls the user interface makes in sequence. To do this, you can use the UI from Firebug or Chrome with developer plugins.
Another alternative is Charles Proxy (http://www.charlesproxy.com/), which offers a visualizer that you may find helpful. While it is commercial software, it can insert itself as an OS X proxy, for example, and intercept both requests from web browsers as well as curl and other API consumers.
Other alternatives include:
Live HTTP headers FireFox extension (https://addons.mozilla.org/en-US/firefox/addon/live-http-headers/)