If you have setup a development environment with RVM to do development in Metasploit Framework you are bound to encounter that the Metasploit team has changed preferred Ruby versions.

Those of you who have taken my "Automating Metasploit Framework" class all this material should not be new. I have decided to start making a large portion of the class available here in the blog as a series. 

On this post I will cover the basics of setting up IRB so we can start exploring in a general sense the Metasploit Framework API. The API is extensive and sadly it would take quite a bit of time over it all, in the series I will covers the basic API calls and provide enough knowledge so you can continue learning the rest on your own or as needed. 

For this you need to be running a development environment. The Metasploit team has documentation on how to setup one https://github.com/rapid7/metasploit-framework/wiki/Setting-Up-a-Metasploit-Development-Environment 

If you are new to Ruby or come from another language and are learning the syntax here is a Ruby Primer.