Quick Start

circe is published to Maven Central and cross-built for Scala 2.12 and 2.13, so you can just add the following to your build:

val circeVersion = "0.14.1"

libraryDependencies ++= Seq(
  "io.circe" %% "circe-core",
  "io.circe" %% "circe-generic",
  "io.circe" %% "circe-parser"
).map(_ % circeVersion)

In case of large or deep-nested case classes, there is a chance to get stack overflow during compilation, please refer to known-issues for workaround.

If you're using the @JsonCodec macro annotations in circe's generic-extras module, you'll need to add -Ymacro-annotations to your compiler options on Scala 2.13, or include the Macro Paradise compiler plugin in your build on earlier Scala versions:

addCompilerPlugin(
  "org.scalamacros" % "paradise" % "2.1.1" cross CrossVersion.full
)

Then type sbt console to start a REPL and then paste the following (this will also work from the root directory of this repository):

import io.circe._, io.circe.generic.auto._, io.circe.parser._, io.circe.syntax._

sealed trait Foo
case class Bar(xs: Vector[String]) extends Foo
case class Qux(i: Int, d: Option[Double]) extends Foo

val foo: Foo = Qux(13, Some(14.0))

val json = foo.asJson.noSpaces
println(json)

val decodedFoo = decode[Foo](json)
println(decodedFoo)

Alternatively you can experiment with circe directly in your browser by clicking the Run button in the code block and making modifications in the code.

No boilerplate, no runtime reflection.