Rex provides a variety of classes useful for security testing and exploit development.



An re-packaging of the Rex library included in the Metasploit Framework for use by non-Metasploit applications. Originally created by Jacob Hammack and made official by the Rapid7 development team. The upstream of this package is the rex subdirectory of

Note that prior to version 2.0.0, the 'rex' gem was an unrelated library developed by Aaron Paterson (@tenderlove).

For users of the prior library (a lexical scanner generator), set your Gemfile to something like the following:

gem 'rex', '< 2.0.0'

This package replaces the librex gem.

$ gem install rex