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What is KOIN?

A pragmatic lightweight dependency injection framework for Kotlin developers.

Written in pure Kotlin, using functional resolution only: no proxy, no code generation, no reflection.

Koin is a DSL, a light container and a pragmatic API

Official Website 👉 https://insert-koin.io

Latest News 🌐

Getting Help 🚒

Any question about Koin usage?

Articles, Videos & other resources 🎉

All online resources about Koin 👉 Talking about Koin

Reporting issues 🛠

Found a bug or a problem on a specific feature? Open an issue on Github issues

Old Koin 1.0 docs - https://old.insert-koin.io

Setup

Current Version

// latest stable
koin_version = '2.0.1'

Gradle

Jcenter

Check that you have the jcenter repository.

// Add Jcenter to your repositories if needed
repositories {
	jcenter()    
}

Dependencies

Pick one of your Koin dependency:

Core features

// Koin for Kotlin
implementation "org.koin:koin-core:$koin_version"
// Koin extended & experimental features
implementation "org.koin:koin-core-ext:$koin_version"
// Koin for Unit tests
testImplementation "org.koin:koin-test:$koin_version"
// Koin for Java developers
implementation "org.koin:koin-java:$koin_version"

Android

// Koin for Android
implementation "org.koin:koin-android:$koin_version"
// Koin Android Scope features
implementation "org.koin:koin-android-scope:$koin_version"
// Koin Android ViewModel features
implementation "org.koin:koin-android-viewmodel:$koin_version"
// Koin Android Experimental features
implementation "org.koin:koin-android-ext:$koin_version"

AndroidX


// Koin AndroidX Scope features
implementation "org.koin:koin-androidx-scope:$koin_version"
// Koin AndroidX ViewModel features
implementation "org.koin:koin-androidx-viewmodel:$koin_version"
// Koin AndroidX Experimental features
implementation "org.koin:koin-androidx-ext:$koin_version"

Ktor

// Koin for Ktor Kotlin
implementation "org.koin:koin-ktor:$koin_version"

Quickstart

Declare a Koin module

Write with the Koin DSL what you need to assemble:

// Given some classes 
class Controller(val service : BusinessService) 
class BusinessService() 

// just declare it 
val myModule = module { 
  single { Controller(get()) } 
  single { BusinessService() } 
} 

Starting Koin

Use the startKoin() function to start Koin in your application.

In a Kotlin app:

fun main(vararg args : String) { 
  // start Koin!
  startKoin {
    // your modules
    modules(myModule)
  }
} 

In an Android app:

class MyApplication : Application() {
  override fun onCreate(){
    super.onCreate()
    // start Koin!
    startKoin {
      // Android context
      androidContext(this@MyApplication)
      // modules
      modules(myModule)
    }
  } 
} 

Talking about Koin

Articles

Videos & Podcasts

Koin Developers Hub

Contributors

This project exists thanks to all the people who contribute. [Contribute]. ekito by koin

OpenCollective

Backers on Open Collective Sponsors on Open Collective

Backers

Thank you to all our backers! 🙏 [Become a backer]

ekito by koin

Sponsors

Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [Become a sponsor]

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compile "org.koin:koin-core:2.0.1"

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