I'm currently using the fb package to write a Yesod app that takes data from Facebook. In my Handler, I've managed to get the first step of the authentication to work, but I need to redirect to the url that getUserAccessTokenStep1 returns, which I've defined as fbRedirUrl. I'm having trouble with all the monad wrapping and type checking to make sure I can redirect to this url. getAccessTokenR :: Handler RepHtml getAccessTokenR = do withManager $ \manager -> do FB.runFacebookT creds manager $ do fbRedirUrl <- FB.getUserAccessTokenStep1 redirUrl [] liftIO $ print fbRedirUrl