Rest And Yii

Hi, i’m developing an application in android that makes a login through facebook and then send to the server where is installed yii a rest query that is something like

Where the open id is the id that facebook send back to me after the login and the provider is the type of the website where i logged in (see here ).

If i find a user, i respond with the data, otherwise i create a new user and then send back the data. But i’m wondering if there’s a secure way to do it, because if i send that command using the add on for firefox, i can add the user or see the data that the server respond.

Thank you for every suggestion or comment!