This script will get the authenticated context info from a SharePoint 2013 list.

getListContext.coffee

user = "domain\\username"
pass = "password"
url  = "http://sharepoint/siteCollection"
list = "listName" 
 
request = require 'request'
 
getListContext = (title, cb)->
  processRequest = (err, res, body)->
    cb(err, JSON.parse(body).d.GetContextWebInformation.FormDigestValue)
  
  config =
    headers :
      Accept: "application/json;odata=verbose"
    url     : "#{url}/lists/#{list}/_api/contextinfo"
  
  request.get(config, processRequest).auth(user, pass, true)
  
getListContext list, (err, contextToken)->
  console.log err || contextToken