How to combine Circe’s semi-automatic derivation with snake case keys took me a little while to find out.

You will need to add the circe module: "io.circe" %% "circe-generic-extras" % "0.8.0".

Here is the code:

import io.circe.generic.extras.Configuration
import io.circe.generic.extras.semiauto._
import io.circe.{Decoder, Encoder}

case class Snaky(someProperty: String)

object Snaky {
  implicit val customConfig: Configuration = Configuration.default.withSnakeCaseKeys.withDefaults
  implicit val snakyEncoder: Encoder[Snaky] = deriveEncoder
  implicit val snakyDecoder: Decoder[Snaky] = deriveDecoder