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Quickstart

Arrow is composed of different libraries; simply select the ones you need in your project.

Multiplatform-ready

All Arrow libraries are Multiplatform-ready, so you can use them in all of your KMP projects. Be aware that some instructions here may need to be slightly changed in that situation.

Enable the Maven Central repository​

Arrow is published in Maven Central, so you need to enable it as a source of dependencies in your build.

repositories {
  mavenCentral()
}

Include the dependencies​

You're now ready to include Arrow in your project. You have three possibilities that correspond to three different ways of handling versioning in your build.

One by one​

Simply include the desired library in your dependencies block or as a <dependency> if you're using Maven.

dependencies {
  implementation("io.arrow-kt:arrow-core:1.2.4")
  implementation("io.arrow-kt:arrow-fx-coroutines:1.2.4")
}

Using version catalogs​

Version catalogs provide centralized management of versions. This is especially interesting when your Gradle build has several subprojects.

[versions]
arrow = "1.2.4"
# other versions

[libraries]
arrow-core = { module = "io.arrow-kt:arrow-core", version.ref = "arrow" }
arrow-fx-coroutines = { module = "io.arrow-kt:arrow-fx-coroutines", version.ref = "arrow" }
# other dependencies

Using a Bill-of-Materials (BOM)​

Another way to keep a single version for all Arrow dependencies in your build is to include arrow-stack, which declares versions for the rest of the components.

dependencies {
  implementation(platform("io.arrow-kt:arrow-stack:1.2.4"))
  // no versions on libraries
  implementation("io.arrow-kt:arrow-core")
  implementation("io.arrow-kt:arrow-fx-coroutines")
}
Eager dependency update policy

The Arrow team follows an eager dependency update policy. That means that Arrow libraries always depend on the most up-to-date version of the dependencies at the moment of release. In most cases, it is fine to use older versions of the dependencies; but in rare cases, the conflict leads to NoClassDefFoundErrors. If that happens, please try to update your dependencies to a more recent version, or open an issue.

Additional setup for plug-ins​

If you're using the Optics component of Arrow, we provide a Kotlin compiler plug-in that can derive most of the boilerplate required to use it. This plug-in is built with KSP, which requires an additional configuration step.

plugins {
  id("com.google.devtools.ksp") version "1.9.24-1.0.20"
}

dependencies {
  implementation("io.arrow-kt:arrow-optics:1.2.4")
  ksp("io.arrow-kt:arrow-optics-ksp-plugin:1.2.4")
}

Plug-in for IntelliJ-based IDEs​

If you are using an IntelliJ IDEA or any other IDE from JetBrains, we strongly recommend installing the Arrow plug-in. The plug-in helps fix common problems, especially in the realm of typed errors and suggests more idiomatic alternatives when available.

Alphas (development builds)​

For those wanting to live on the edge, we provide alphas of our development branch. Those are tagged with the upcoming version, followed by -alpha. and the sequence number of the compilation. Check Maven Central for the most recent list of available versions.