README.md

Kebs

Scala library to eliminate boilerplate

A library maintained by Iterators. Supports Scala 2.13 and Scala 3.

What is Kebs?

Kebs automatically derives typeclass instances (JSON codecs, DB column mappings, HTTP unmarshallers, etc.) for your domain types so you don't have to write them by hand.

case class UserId(value: String) extends AnyVal
case class Email(value: String) extends AnyVal

// Without Kebs — manual boilerplate for every type × every library:
implicit val userIdCol: BaseColumnType[UserId] = MappedColumnType.base(_.value, UserId.apply)
implicit val userIdEnc: Encoder[UserId] = Encoder[String].contramap(_.value)
// ... repeat dozens of times

// With Kebs — just mix in a trait. Everything is derived at compile time.

Documentation

https://theiterators.github.io/kebs/

Quick start

// build.sbt — pick the modules you need
libraryDependencies ++= Seq(
  "pl.iterators" %% "kebs-slick"      % "2.1.6",
  "pl.iterators" %% "kebs-circe"      % "2.1.6",
  "pl.iterators" %% "kebs-pekko-http" % "2.1.6",
  "pl.iterators" %% "kebs-instances"  % "2.1.6"
)

Available modules

Module	What you get
kebs-slick	Automatic Slick column type mappings, Postgres array & hstore support
kebs-doobie	Doobie Meta / Get / Put instances
kebs-spray-json	Spray JsonFormat derivation (flat, snakified, >22 fields)
kebs-play-json	Play JSON Format instances
kebs-circe	Circe Encoder / Decoder derivation (snakified/capitalized)
kebs-akka-http	Akka HTTP unmarshallers + path matchers (Scala 2 only)
kebs-pekko-http	Pekko HTTP unmarshallers + path matchers
kebs-http4s	http4s path/query parameter codecs
kebs-http4s-stir	http4s-stir directives + path matchers
kebs-scalacheck	Arbitrary instance generation
kebs-pureconfig	PureConfig ConfigReader / ConfigWriter
kebs-jsonschema	JSON Schema generation (Scala 2 only)
kebs-baklava	Baklava schema + parameter support
kebs-tagged	Tagged types for Scala 2
kebs-tagged-meta	@tagged code generation (Scala 2 only)
kebs-opaque	Opaque type support for Scala 3
kebs-enum	Scala 3 native enums + Scala 2 Enumeration
kebs-enumeratum	Enumeratum support (Scala 2 & 3)
kebs-instances	Pre-built converters for java.time, UUID, URI, etc.

Kebs 2.0 migration guide

• Mix in CaseClass1ToValueClass if you use value classes.
• Extend value-enums with ValueEnumLikeEntry[V].
• Use KebsEnumeratum / KebsValueEnumeratum for Enumeratum, KebsEnum / KebsValueEnum for native enums.
• See the full documentation for details.

IntelliJ support

Kebs for IntelliJ plugin adds support for @tagged generated code.