This application is based off of the guide http://guides.grails.org/react-spring-security/guide/index.html. It is basically an extended example where the ability to authenticate using Google OAuth2 has been added. There are additional stub blocks for Facebook and Twitter. To get Google auth working just add your client key and secret to the appropriate location in the application.groovy file and it should work. Facebook should work similarly, add your client key and secret to application.groovy. Facebook may have an issue, in a quick trial run could not get all the way through the login process.