Access Route Request Headers

I need to access a custom header (set by a proxy) when my ember route is hit. Typically in an expressjs app I would do it like this:

app.get('/', function(req, res){
  req.get('Custom-Header');
});

I can’t seem to find a request object in ember routes. How can I get at this information? It contains some information about the authenticated user that I want to persist across the app.

Ember runs on the client side. There is no way AFAIK to access the current page’s headers in javascript on the client side.