Scala Kindlings Derivation

Scala Kindlings Derivation

Quick start

• Use Kindlings to derive type class instances; keep using library APIs for actual work.
  • Circe: derive Encoder, Decoder, or Codec.AsObject; keep using asJson, decode, parsers, printers.
  • PureConfig: derive ConfigReader, ConfigWriter, or ConfigConvert; keep using ConfigSource.load and PureConfig writers.
• Prefer companion-object instances for root types used at call sites; nested product types are derived as needed.
• Configure derivation with Kindlings config values/hints, not with Circe/PureConfig generic imports.
• Do not import io.circe.generic.auto._, io.circe.generic.semiauto._, pureconfig.generic.auto._, or pureconfig.generic.semiauto._ when using Kindlings.

APIs to reach for

• Circe JSON:
  • Use KindlingsEncoder.derived[A], KindlingsDecoder.derived[A], or KindlingsCodecAsObject.derived[A].
  • For one-off operations, use KindlingsEncoder.encode(value) or KindlingsDecoder.decode[A](json).
  • Cross-platform.
  • Default field names are unchanged.
  • ADTs are wrapped unless a discriminator is configured.
• PureConfig HOCON:
  • Use KindlingsConfigReader.derived[A], KindlingsConfigWriter.derived[A], or KindlingsConfigConvert.derived[A].
  • JVM-only.
  • Defaults match PureConfig: kebab-case keys, type discriminator, defaults enabled, unknown keys allowed.

References

• Load references/circe-derivation.md for Circe derivation, annotations, discriminators, and migration notes.
• Load references/pureconfig-derivation.md for PureConfig derivation, default conventions, discriminator configuration, and supported PureConfig knobs.
• Load references/best-practices.md for organization, call-site hygiene, and validation guidance.