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Flagsmith Android/Kotlin SDK

This SDK can be used for Android applications written in Kotlin. The source code for the client is available on Github.


Gradle - App

In your project path app/build.gradle add a new dependence

implementation 'com.github.Flagsmith:flagsmith-kotlin-android-client:1.0.1'

You should be able to find the latest version in the releases section of the GitHub repository.

Gradle - Project

In the new Gradle version 7+ update your settings.gradle file to include JitPack if you haven't already

repositories {

maven { url "" }

Basic Usage

The SDK is initialised against a single environment within a project on, for example the Development or Production environment. You can find your Client-side Environment Key in the Environment settings page.



Within your Activity inside onCreate()

lateinit var flagsmith : Flagsmith

override fun onCreate(savedInstanceState: Bundle?) {

private fun initFlagsmith() {
flagsmith = Flagsmith(environmentKey = FlagsmithConfigHelper.environmentDevelopmentKey, context = context)

Custom configuration

The Flagsmith SDK has various parameters for initialisation. Most of these are optional, and allow you to configure the Flagmsith SDK to your specific needs:

  • environmentKey Take this API key from the Flagsmith dashboard and pass here
  • baseUrl By default we'll connect to the Flagsmith backend, but if you self-host you can configure here
  • context The current Context is required to use the Flagsmith Analytics functionality
  • enableAnalytics Enable analytics - default true. Disable this if you'd like to avoid the use of Context
  • analyticsFlushPeriod The period in seconds between attempts by the Flagsmith SDK to push analytic events to the server


Now you are all set to retrieve feature flags from your project. For example to list and print all flags:

flagsmith.getFeatureFlags { result ->
onSuccess = { flagList ->
Log.i("Flagsmith", "Current flags:")
flagList.forEach { Log.i("Flagsmith", "- ${} - enabled: ${it.enabled} value: ${it.featureStateValue ?: "not set"}") }
onFailure = { err ->
Log.e("Flagsmith", "Error getting feature flags", err)

Get Flag Object by featureId

To retrieve a feature flag boolean value by its name:

flagsmith.hasFeatureFlag(forFeatureId = "test_feature1") { result ->
val isEnabled = result.getOrDefault(true)
Log.i("Flagsmith", "test_feature1 is enabled? $isEnabled")

Create a Trait for a user identity

flagsmith.setTrait(Trait(key = "set-from-client", value = "12345"), identity = "") { result ->
onSuccess = { _ ->
Log.i("Flagsmith", "Successfully set trait")

onFailure = { err ->
Log.e("Flagsmith", "Error setting trait", err)

Get all Traits

To retrieve a trait for a particular identity as explained here Traits

flagsmith.getTraits(identity = "") { result ->
onSuccess = { traits ->
traits.forEach {
Log.i("Flagsmith", "Trait - ${it.key} : ${it.value}")
onFailure = { err ->
Log.e("Flagsmith", "Error setting trait", err)

Override the default base URL

If you'd like to use your own API URL you can override this like so during initialization:

        flagsmith = Flagsmith(
environmentKey = Helper.environmentDevelopmentKey,
context = context,
baseUrl = "")