Rails Google Oauth Authentication

I am using google oauth gem. Actually I have two rails app, one is Api Server and other one can be considered as frontend part i.e it fetches the data from Api Server and displays it. I am using token(which Api Server provides after user login) to query data from Api Server. Now my user model is present on Api Server, so when user clicks on google login, I have to redirect him to some api on Api Server, which then redirects to Google Authentication. Now the callback method for google authentication is also present on Api Server. So, after authentication the token is generated in callback method, but I have to give this token back to frontend app, from where actually the use clicked on google login. Currently I am storing that token in browser session in google authentication callback method(this is creating other issues) itself. Is there any other way in which this can be achieved, without storing the token in browser session?