How to integrate servant-auth for JWT based authentication?

[bdoering]

Thank you for this starter project! Being relatively new to Haskell, the structure seems clear and easy to follow with nice separation of concerns.

I would like to integrate the servant-auth library for easy JWT authentication, but whatever I try, I do not get it to compile. Could maybe somebody give me an indication about the general approach that would be necessary?
What I tried:

• I took this tutorial as a general guide: https://haskell-servant.readthedocs.io/en/stable/cookbook/hoist-server-with-context/HoistServerWithContext.html.
• I created a new "Effect" to abstract the IO away from acceptLogin.
• Already here I get an "Overlapping Instances" error arising from a use of Servant.Auth.Server.acceptLogin

Maybe I have approached this all wrong? How would you use JWT authentication without repeating authentication logic for each handler?