CallingAPI

var request = new Request();
request.url = bla
request.header = {
  // If he used session
  Authorization: 'Bearer ' + A0Session.store.idToken
}

request.make();

Checking for expired token

if (A0Session.isTokenExpired()) {
  A0Session.refreshTokens(function(token, profile) {
    A0Session.storeInfo(token, profile);
  });
}

LoginPage

var login = new LoginController();

login.onAuthentication(function(profile, tokenObj) {
  // Do something with Profile and Token
  // YOu can save it using the SDK
  A0Session.storeInfo(profile, tokenObj);
});