Aggcat SAML request in Node.js

I'm developing an application that will interface with Intuit's aggcat service. I'm writing the application in Node.js. Right now I'm stuck on creating the SAML request. I've searched for a module that provides a means of sending a SAML request, but I have not been successful in finding one. I've seen a couple that allow you to receive a request, but not send. Can someone point me in the right direction?