How does Facebook authentication work?

Oct 17, 2009 at 5:18 AM

Hi Everyone,

I have been using the Facebook Developer Kit to develop a Facebook Canvas iFrame application. It all works really well. But I am unclear about a certain technical detail. How exactly does my web server know the uid of the user who has logged into Facebook? Does anyone know what sort of token is sent to my server? Is it a POST? Is it a querystring? How is it formatted, etc?

How can I access it? Both on the client side (AJAX) and the server side (in ASP.Net)? I would like to have control of this token so that I can pass it to an embedded Flash application so that it too can contact my web server as the logged in user. I am really stuck on this so any help would be really appreciated!

Thanks a lot!