Gonzalo Ayuso has posted a tutorial showing how to use token-based authentication with a Silex-based application through a request from AngularJS.

According to my last post today we’re going to create a AngularJS application that uses the Silex Backend that we create previously. The idea of this application is to use it within a Phonegap/Cordova application running in a mobile device.

He includes the code (and markup) you'll need to make the request work. Basically, it uses a standard HTTP service from inside AngularJS to fetch the token and store it in the client's localstorage. The rest of the code does the checking to see if the user is logged in (the token exists) or if it needs to sow the login form. The "logged in" route also displays an alert to the user with the info (pulled from the API) for their user. The full code for the example can be found over on GitHub.