Silverstripe-congressapi is a project mainly written in PHP and JAVASCRIPT, it's free.
A SilverStripe module for accessing the Sunlight Labs Congress API
A SilverStripe module that allows for easy lookup of US congressional representatives based on geographical location.
This module was developed for use with the Sunlight Labs Congress API.
Add the module folder to the root folder of your SS project. You should then be able to add the Sunlight Services API key in the "Site Config" section of your projects CMS admin interface.