Once you can authenticate your users, you can use their credentials to authorize requests. Authorization in Yesod is simple and declarative: most of the time, you just need to add the authRoute and isAuthorized methods to your Yesod typeclass instance. Let’s see an example.

{-# LANGUAGE OverloadedStrings, TemplateHaskell, TypeFamilies,
             MultiParamTypeClasses, QuasiQuotes #-}
import Yesod
import Yesod.Auth
import Yesod.Auth.Dummy -- just for testing, don't use in real life!!!
import Data.Text (Text)
import Network.HTTP.Conduit (Manager, newManager, def)

data MyAuthSite = MyAuthSite
    { httpManager :: Manager
    }

mkYesod "MyAuthSite" [parseRoutes|
/ RootR GET POST