Fork me on GitHub

Alex Rupérez

Published: 07 Jun 13:40
I starred 47deg/helios at GitHub.
A purely functional JSON library for Kotlin built on Λrrow -
View on GitHub



Helios is a library used to transform Json text into a model and vice versa. It's based on part of the Jawn Parser built on Arrow, a Functional companion to Kotlin's Standard Library.

Learn more on

Why Helios

Helios is one of the fastest Json parser libraries in Kotlin with the advantage of using the Arrow library for functional programming.

Adding the dependency

Helios uses Kotlin version 1.3.31 and Arrow version 0.9.0.

To import the library on Gradle, add the following repository and dependencies:

repositories {
    maven { url = uri("") }

dependencies {
    compile "com.47deg:helios-core:0.2.0"
    compile "com.47deg:helios-parser:0.2.0"
    compile "com.47deg:helios-optics:0.2.0"
    kapt "com.47deg:helios-meta:0.2.0"
    kapt "com.47deg:helios-dsl-meta:0.2.0"

Running Benchmarks

To run the benchmarks for comparing Helios with other Json libraries, execute the following command:

./gradlew :helios-benchmarks:executeBenchmarks

To run the benchmarks with Helios' performance, execute the following command:

./gradlew :helios-benchmarks:executeHeliosBenchmark

Running Microsite

To run the Helios microsite locally, you need to execute the following command:

bundle install --gemfile ./docs/Gemfile --path vendor/bundle

Next, you'll be able to run the following command:

BUNDLE_GEMFILE=docs/Gemfile bundle exec jekyll serve -s docs