cool. thanks @ndchorley - keep plugging away and le tus know where the pain points are (if any!)! 🙂 In terms of a (planned) http4k-session module, I'm intending to provide an a. an interface for session persistence, and b. to use the Lens API to make the session management completely typesafe using SessionKey Lenses. This will make it consistent with the rest of the http4k APIs, so should fit in quite nicely. Now we just need the time (or volunteers) to do the dev work! 🙂