If you're an Elm developer writing Haskell and you like elm/json , you might like dwayne/hs-json-codec . hs-json-codec provides JSON decoders and encoders for Haskell in the style of elm/json . It's built on dwayne/hs-json-parser , a general-purpose JSON parser and printer that I also wrote. I built both libraries because I wanted them for dwayne/elm2nix , but they can be used in any Haskell project. In this post, I'll introduce their APIs and show how I use them in elm2nix...