diff --git a/openfeature/providers/kotlin-provider/.gitignore b/openfeature/providers/kotlin-provider/.gitignore
new file mode 100644
index 00000000000..aa724b77071
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/.gitignore
@@ -0,0 +1,15 @@
+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.cxx
+local.properties
diff --git a/openfeature/providers/kotlin-provider/README.md b/openfeature/providers/kotlin-provider/README.md
new file mode 100644
index 00000000000..30480007ba7
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/README.md
@@ -0,0 +1,93 @@
+# GO Feature Flag Kotlin OpenFeature Provider for Android
+
+![Static Badge](https://img.shields.io/badge/status-experimental-red)
+
+This OpenFeature provider is a Kotlin implementation for Android to communicate with the GO Feature
+Flag Server.
+
+The OpenFeature Kotlin is experimental, and the provider is also experimental.
+We don't recommend using this in production yet.
+
+## About this provider
+
+[GO Feature Flag](https://gofeatureflag.org) provider allows you to connect to your GO Feature Flag
+instance with the OpenFeature Kotlin SDK.
+
+This is a client provider made for Android, we do not recommend using it in a server environment.
+If you want to use it in a server environment, you should use
+the [`Java` provider](https://gofeatureflag.org/docs/openfeature_sdk/server_providers/openfeature_java).
+
+## What is GO Feature Flag?
+
+GO Feature Flag is a simple, complete and lightweight self-hosted feature flag solution 100% Open
+Source.
+Our focus is to avoid any complex infrastructure work to use GO Feature Flag.
+
+This is a complete feature flagging solution with the possibility to target only a group of users,
+use any types of flags, store your configuration in various location and advanced rollout
+functionality. You can also collect usage data of your flags and be notified of configuration
+changes.
+
+## Install the provider
+
+TODO
+
+## How to use the provider?
+
+```kotlin
+val evaluationContext = ImmutableContext(
+ targetingKey = "0a23d9a5-0a8f-42c9-9f5f-4de3afd6cf99",
+ attributes = mutableMapOf(
+ "region" to Value.String("us-east-1"),
+ "email" to Value.String("john.doe@gofeatureflag.org")
+ )
+)
+
+OpenFeatureAPI.setProvider(
+ GoFeatureFlagProvider(
+ options = GoFeatureFlagOptions(
+ endpoint = "http://localhost:1031"
+ )
+ ), evaluationContext
+)
+
+val client = OpenFeatureAPI.getClient("my-client")
+if (client.getBooleanValue("my-flag", false)) {
+ println("my-flag is enabled")
+}
+OpenFeatureAPI.shutdown()
+```
+
+### Available options
+
+| Option name | Type | Default | Description |
+|--------------------|--------|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| endpoint | String | | endpoint is the URL where your GO Feature Flag server is located. |
+| timeout | Long | 10000 | (optional) timeout is the time in millisecond we wait for an answer from the server. |
+| maxIdleConnections | Int | 1000 | (optional) maxIdleConnections is the maximum number of connexions in the connexion pool. |
+| keepAliveDuration | Long | 7200000 | (optional) keepAliveDuration is the time in millisecond we keep the connexion open. |
+| apiKey | String | | (optional) If GO Feature Flag is configured to authenticate the requests, you should provide an API Key to the provider. Please ask the administrator of the relay proxy to provide an API Key. |
+| retryDelay | Long | 300 | (optional) delay in millisecond to wait before retrying to connect the websocket |
+
+### Reconnection
+
+If the connection to the GO Feature Flag instance fails, the provider will attempt to reconnect.
+
+### Event streaming
+
+Event streaming is not implemented yet in the GO Feature Flag provider.
+
+## Features status
+
+| Status | Feature | Description |
+|--------|--------------------|--------------------------------------------------------------------------------------|
+| ✅ | Flag evaluation | It is possible to evaluate all the type of flags |
+| ✅ | Cache invalidation | Websocket mechanism is in place to refresh the cache in case of configuration change |
+| ❌ | Logging | Not supported by the SDK |
+| ❌ | Flag Metadata | Not supported by the SDK |
+| ❌ | Event Streaming | Not implemented |
+| ❌ | Unit test | Not implemented |
+
+Implemented: ✅ | In-progress: ⚠️ | Not implemented yet: ❌
+
+
diff --git a/openfeature/providers/kotlin-provider/build.gradle.kts b/openfeature/providers/kotlin-provider/build.gradle.kts
new file mode 100644
index 00000000000..e52cca11b5d
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/build.gradle.kts
@@ -0,0 +1,14 @@
+// Top-level build file where you can add configuration options common to all sub-projects/modules.
+plugins {
+ id("com.android.application") version "8.1.2" apply false
+ id("org.jetbrains.kotlin.android") version "1.9.0" apply false
+ id("com.android.library") version "8.1.2" apply false
+}
+
+allprojects {
+ extra["groupId"] = "org.gofeatureflag.openfeature"
+ ext["version"] = "0.0.1"
+}
+
+group = project.extra["groupId"].toString()
+version = project.extra["version"].toString()
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/.gitignore b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/.gitignore
new file mode 100644
index 00000000000..42afabfd2ab
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/.gitignore
@@ -0,0 +1 @@
+/build
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/build.gradle.kts b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/build.gradle.kts
new file mode 100644
index 00000000000..a3c6520e08c
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/build.gradle.kts
@@ -0,0 +1,44 @@
+plugins {
+ id("com.android.library")
+ id("org.jetbrains.kotlin.android")
+}
+
+val releaseVersion = project.extra["version"].toString()
+
+android {
+ namespace = "org.gofeatureflag.openfeature"
+ compileSdk = 33
+
+ defaultConfig {
+ minSdk = 21
+ version = releaseVersion
+ testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+ }
+
+ buildTypes {
+ release {
+ isMinifyEnabled = false
+ proguardFiles(
+ getDefaultProguardFile("proguard-android-optimize.txt"),
+ "proguard-rules.pro"
+ )
+ }
+ }
+ compileOptions {
+ sourceCompatibility = JavaVersion.VERSION_11
+ targetCompatibility = JavaVersion.VERSION_11
+ }
+ kotlinOptions {
+ jvmTarget = JavaVersion.VERSION_11.toString()
+ }
+}
+
+dependencies {
+ implementation("dev.openfeature:kotlin-sdk:0.0.4")
+ implementation("com.squareup.okhttp3:okhttp:4.12.0")
+ implementation("com.google.code.gson:gson:2.8.9")
+ implementation("dev.gustavoavila:java-android-websocket-client:2.0.2")
+ testImplementation("junit:junit:4.13.2")
+ testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.7.3")
+ testImplementation("com.squareup.okhttp3:mockwebserver:4.12.0")
+}
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/consumer-rules.pro b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/consumer-rules.pro
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/proguard-rules.pro b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/proguard-rules.pro
new file mode 100644
index 00000000000..481bb434814
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+# http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+# public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/AndroidManifest.xml b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/AndroidManifest.xml
new file mode 100644
index 00000000000..a5918e68abc
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/AndroidManifest.xml
@@ -0,0 +1,4 @@
+
+
+
+
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/GoFeatureFlagMetadata.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/GoFeatureFlagMetadata.kt
new file mode 100644
index 00000000000..f58c0eb00a3
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/GoFeatureFlagMetadata.kt
@@ -0,0 +1,9 @@
+package org.gofeatureflag.openfeature
+
+import dev.openfeature.sdk.ProviderMetadata
+import java.security.Provider
+
+class GoFeatureFlagMetadata() : ProviderMetadata {
+ override val name: String
+ get() = "GoFeatureFlagProvider"
+}
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/GoFeatureFlagProvider.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/GoFeatureFlagProvider.kt
new file mode 100644
index 00000000000..66b44fed03d
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/GoFeatureFlagProvider.kt
@@ -0,0 +1,271 @@
+package org.gofeatureflag.openfeature
+
+import com.google.gson.Gson
+import dev.gustavoavila.websocketclient.WebSocketClient
+import dev.openfeature.sdk.EvaluationContext
+import dev.openfeature.sdk.FeatureProvider
+import dev.openfeature.sdk.Hook
+import dev.openfeature.sdk.OpenFeatureAPI.getEvaluationContext
+import dev.openfeature.sdk.ProviderEvaluation
+import dev.openfeature.sdk.ProviderMetadata
+import dev.openfeature.sdk.Reason
+import dev.openfeature.sdk.Value
+import dev.openfeature.sdk.exceptions.ErrorCode
+import dev.openfeature.sdk.exceptions.OpenFeatureError.FlagNotFoundError
+import dev.openfeature.sdk.exceptions.OpenFeatureError.GeneralError
+import okhttp3.ConnectionPool
+import okhttp3.HttpUrl
+import okhttp3.HttpUrl.Companion.toHttpUrlOrNull
+import okhttp3.MediaType.Companion.toMediaTypeOrNull
+import okhttp3.OkHttpClient
+import okhttp3.RequestBody.Companion.toRequestBody
+import org.gofeatureflag.openfeature.bean.FlagState
+import org.gofeatureflag.openfeature.bean.GoFeatureFlagOptions
+import org.gofeatureflag.openfeature.bean.GoffRequest
+import org.gofeatureflag.openfeature.bean.GoffResponse
+import org.gofeatureflag.openfeature.bean.ProviderStatus
+import org.gofeatureflag.openfeature.exception.InvalidEndpoint
+import java.net.HttpURLConnection.HTTP_BAD_REQUEST
+import java.net.HttpURLConnection.HTTP_UNAUTHORIZED
+import java.net.URI
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.TimeUnit
+
+
+class GoFeatureFlagProvider(private val options: GoFeatureFlagOptions) : FeatureProvider {
+ companion object {
+ private val gson = Gson()
+ }
+
+ private var httpClient: OkHttpClient = OkHttpClient.Builder()
+ .connectTimeout(this.options.timeout, TimeUnit.MILLISECONDS)
+ .readTimeout(this.options.timeout, TimeUnit.MILLISECONDS)
+ .callTimeout(this.options.timeout, TimeUnit.MILLISECONDS)
+ .writeTimeout(this.options.timeout, TimeUnit.MILLISECONDS)
+ .connectionPool(
+ ConnectionPool(
+ this.options.maxIdleConnections,
+ this.options.keepAliveDuration,
+ TimeUnit.MILLISECONDS
+ )
+ )
+ .build()
+ private var parsedEndpoint: HttpUrl? = options.endpoint.toHttpUrlOrNull()
+ private var flags: ConcurrentHashMap = ConcurrentHashMap()
+ private var status: ProviderStatus = ProviderStatus.NOT_READY
+ private var goffWebsocketClient: WebSocketClient? = null
+
+ init {
+ if (this.parsedEndpoint == null) {
+ throw InvalidEndpoint()
+ }
+ }
+
+ override val hooks: List>
+ get() = listOf()
+
+ override val metadata: ProviderMetadata
+ get() = GoFeatureFlagMetadata()
+
+ override fun getBooleanEvaluation(
+ key: String,
+ defaultValue: Boolean,
+ context: EvaluationContext?
+ ): ProviderEvaluation {
+ return this.evaluate(key, listOf("Boolean"), defaultValue)
+ }
+
+ override fun getDoubleEvaluation(
+ key: String,
+ defaultValue: Double,
+ context: EvaluationContext?
+ ): ProviderEvaluation {
+ return this.evaluate(key, listOf("Double"), defaultValue)
+ }
+
+ override fun getIntegerEvaluation(
+ key: String,
+ defaultValue: Int,
+ context: EvaluationContext?
+ ): ProviderEvaluation {
+ return this.evaluate(key, listOf("Int"), defaultValue)
+ }
+
+ override fun getObjectEvaluation(
+ key: String,
+ defaultValue: Value,
+ context: EvaluationContext?
+ ): ProviderEvaluation {
+ return this.evaluate(key, listOf("LinkedTreeMap", "ArrayList"), defaultValue)
+ }
+
+ override fun getStringEvaluation(
+ key: String,
+ defaultValue: String,
+ context: EvaluationContext?
+ ): ProviderEvaluation {
+ return this.evaluate(key, listOf("String"), defaultValue)
+ }
+
+ override fun initialize(initialContext: EvaluationContext?) {
+ try {
+ fetchAllFlags(initialContext)
+ this.goffWebsocketClient =
+ object : WebSocketClient(buildWebsocketURI(this.options)) {
+ init {
+ this.enableAutomaticReconnection(options.retryDelay)
+ this.setReadTimeout(options.timeout.toInt())
+ this.setConnectTimeout(options.timeout.toInt())
+ }
+
+ override fun onOpen() {
+ status = ProviderStatus.READY
+ }
+
+ override fun onTextReceived(message: String?) {
+ try {
+ status = ProviderStatus.STALE
+ fetchAllFlags(getEvaluationContext())
+ status = ProviderStatus.READY
+ } catch (e: Exception) {
+ status = ProviderStatus.ERROR
+ }
+ }
+
+ override fun onException(e: java.lang.Exception?) {
+ status = ProviderStatus.ERROR
+ }
+
+ override fun onBinaryReceived(data: ByteArray?) {}
+ override fun onPingReceived(data: ByteArray?) {}
+ override fun onPongReceived(data: ByteArray?) {}
+ override fun onCloseReceived(reason: Int, description: String?) {}
+ }
+ this.goffWebsocketClient?.connect()
+ } catch (e: Exception) {
+ this.status = ProviderStatus.ERROR
+ }
+ }
+
+ override fun onContextSet(oldContext: EvaluationContext?, newContext: EvaluationContext) {
+ this.status = ProviderStatus.STALE
+ try {
+ fetchAllFlags(newContext)
+ this.status = ProviderStatus.READY
+ } catch (e: Exception) {
+ this.status = ProviderStatus.ERROR
+ }
+ }
+
+ override fun shutdown() {
+ this.goffWebsocketClient?.close(0, 1000, "stop provider")
+ }
+
+ fun status(): ProviderStatus {
+ return this.status
+ }
+
+ /**
+ * Evaluate is the function call by all types to fetch the flag from the cache
+ * and return the ProviderEvaluation object.
+ *
+ * @param flagKey the key of the flag to fetch
+ * @param expectedTypes the types of the flag to fetch
+ * @param defaultValue the default value to return if there is an error
+ *
+ * @return ProviderEvaluation the evaluation of the flag
+ */
+ private fun evaluate(
+ flagKey: String,
+ expectedTypes: List,
+ defaultValue: T
+ ): ProviderEvaluation {
+ if (this.status == ProviderStatus.NOT_READY) {
+ return ProviderEvaluation(
+ value = defaultValue,
+ variant = null,
+ reason = Reason.ERROR.toString(),
+ errorCode = ErrorCode.PROVIDER_NOT_READY
+ )
+ }
+
+ val flag = this.flags[flagKey] ?: throw FlagNotFoundError(flagKey)
+
+ if (!expectedTypes.contains(flag.value::class.simpleName)) {
+ // TODO: throw here when the SDK with this PR https://github.com/open-feature/kotlin-sdk/pull/64/files is released
+ // throw TypeMismatchError()
+ return ProviderEvaluation(
+ value = defaultValue,
+ variant = flag.variationType,
+ reason = Reason.ERROR.toString(),
+ errorCode = ErrorCode.TYPE_MISMATCH
+ )
+ }
+
+ val errorCode: ErrorCode? = try {
+ ErrorCode.valueOf(flag.errorCode)
+ } catch (e: IllegalArgumentException) {
+ null
+ }
+
+ return ProviderEvaluation(
+ value = flag.value as T,
+ variant = flag.variationType,
+ reason = flag.reason,
+ errorCode = errorCode
+ )
+ }
+
+ /** fetchAllFlags is the function called to fetch all flags from the relay proxy
+ * and store them in the cache.
+ *
+ * @param context the context to use to fetch the flags
+ */
+ private fun fetchAllFlags(context: EvaluationContext?) {
+ if (context == null) {
+ return
+ }
+ val goffctx = GoffRequest(context)
+ val urlBuilder = parsedEndpoint!!.newBuilder()
+ .addEncodedPathSegment("v1")
+ .addEncodedPathSegment("allflags")
+
+ if (this.options.apiKey != null && this.options.apiKey.trim().isNotEmpty()) {
+ urlBuilder.addQueryParameter("apiKey", this.options.apiKey)
+ }
+
+ // call an API endpoint to fetch all flags
+ val mediaType = "application/json".toMediaTypeOrNull()
+ val requestBody = gson.toJson(goffctx).toRequestBody(mediaType)
+ val reqBuilder = okhttp3.Request.Builder()
+ .url(urlBuilder.build())
+ .post(requestBody)
+
+ httpClient.newCall(reqBuilder.build()).execute().use { response ->
+ if (response.code == HTTP_UNAUTHORIZED) {
+ throw GeneralError("invalid token used to contact GO Feature Flag relay proxy instance")
+ }
+ if (response.code >= HTTP_BAD_REQUEST) {
+ throw GeneralError("impossible to contact GO Feature Flag relay proxy instance")
+ }
+
+ val t = response.body?.string()
+ val parsedResp = gson.fromJson(t, GoffResponse::class.java)
+ this.flags = ConcurrentHashMap(parsedResp.flags)
+ }
+ }
+
+ /** buildWebsocketURI is the function called to build the websocket URI
+ * to connect to the relay proxy.
+ *
+ * @param options the options to use to build the URI
+ * @return URI the URI to connect to
+ */
+ private fun buildWebsocketURI(options: GoFeatureFlagOptions): URI {
+ // take the endpoint and replace http:// or https:// by ws:// or wss://
+ val wsEndpoint = options.endpoint
+ .replaceFirst("http", "ws")
+ .replaceFirst("https", "wss")
+ return URI("$wsEndpoint/ws/v1/flag/change")
+ }
+}
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/FlagState.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/FlagState.kt
new file mode 100644
index 00000000000..06315ef8941
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/FlagState.kt
@@ -0,0 +1,12 @@
+package org.gofeatureflag.openfeature.bean
+
+data class FlagState(
+ val value: Any,
+ val timestamp: Long,
+ val variationType: String,
+ val trackEvents: Boolean,
+ val failed: Boolean,
+ val errorCode: String,
+ val reason: String,
+ val metadata: Map?
+)
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoFeatureFlagOptions.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoFeatureFlagOptions.kt
new file mode 100644
index 00000000000..9318e1bf0d7
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoFeatureFlagOptions.kt
@@ -0,0 +1,42 @@
+package org.gofeatureflag.openfeature.bean
+
+data class GoFeatureFlagOptions(
+ /**
+ * (mandatory) endpoint contains the DNS of your GO Feature Flag relay proxy
+ * example: https://mydomain.com/gofeatureflagproxy/
+ */
+ val endpoint: String,
+
+ /**
+ * (optional) timeout in millisecond we are waiting when calling the
+ * go-feature-flag relay proxy API.
+ * Default: 10000 ms
+ */
+ val timeout: Long = 10000,
+
+ /**
+ * (optional) maxIdleConnections is the maximum number of connexions in the connexion pool.
+ * Default: 1000
+ */
+ val maxIdleConnections: Int = 1000,
+
+ /**
+ * (optional) keepAliveDuration is the time in millisecond we keep the connexion open.
+ * Default: 7200000 (2 hours)
+ */
+ val keepAliveDuration: Long = 7200000,
+
+ /**
+ * (optional) apiKey, if the relay proxy is configured to authenticate the requests, you should provide
+ * an API Key to the provider.
+ * Please ask the administrator of the relay proxy to provide an API Key.
+ * (This feature is available only if you are using GO Feature Flag relay proxy v1.7.0 or above)
+ * Default: null
+ */
+ val apiKey: String? = null,
+
+ /** (optional) retryDelay is the time in millisecond we wait before retrying to connect to the relay proxy.
+ * Default: 1000 ms
+ */
+ val retryDelay: Long = 1000,
+)
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoffEvaluationContext.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoffEvaluationContext.kt
new file mode 100644
index 00000000000..0f2e15735d8
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoffEvaluationContext.kt
@@ -0,0 +1,4 @@
+package org.gofeatureflag.openfeature.bean
+
+data class GoffEvaluationContext(val key: String, val custom: Map) {
+}
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoffRequest.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoffRequest.kt
new file mode 100644
index 00000000000..cbc88a96584
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoffRequest.kt
@@ -0,0 +1,8 @@
+package org.gofeatureflag.openfeature.bean
+
+import dev.openfeature.sdk.EvaluationContext
+
+data class GoffRequest(@Transient val ctx: EvaluationContext) {
+ private val evaluationContext: GoffEvaluationContext =
+ GoffEvaluationContext(ctx.getTargetingKey(), ctx.asObjectMap())
+}
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoffResponse.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoffResponse.kt
new file mode 100644
index 00000000000..ff4a0add1b8
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/GoffResponse.kt
@@ -0,0 +1,7 @@
+package org.gofeatureflag.openfeature.bean
+
+data class GoffResponse(
+ val flags: Map,
+ val valid: Boolean
+)
+
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/ProviderStatus.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/ProviderStatus.kt
new file mode 100644
index 00000000000..140c721f8f8
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/bean/ProviderStatus.kt
@@ -0,0 +1,23 @@
+package org.gofeatureflag.openfeature.bean
+
+enum class ProviderStatus {
+ /**
+ * The provider has not been initialized and cannot yet evaluate flags.
+ */
+ NOT_READY,
+
+ /**
+ * The provider is ready to resolve flags.
+ */
+ READY,
+
+ /**
+ * The provider is in an error state and unable to evaluate flags.
+ */
+ ERROR,
+
+ /**
+ * The provider's cached state is no longer valid and may not be up-to-date with the source of truth.
+ */
+ STALE
+}
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/exception/GoFeatureFlagException.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/exception/GoFeatureFlagException.kt
new file mode 100644
index 00000000000..7d6d9a9adf9
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/exception/GoFeatureFlagException.kt
@@ -0,0 +1,4 @@
+package org.gofeatureflag.openfeature.exception
+
+open class GoFeatureFlagException(): Exception() {
+}
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/exception/InvalidEndpoint.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/exception/InvalidEndpoint.kt
new file mode 100644
index 00000000000..bf836fcc8db
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/exception/InvalidEndpoint.kt
@@ -0,0 +1,4 @@
+package org.gofeatureflag.openfeature.exception
+
+class InvalidEndpoint(): InvalidOptions() {
+}
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/exception/InvalidOptions.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/exception/InvalidOptions.kt
new file mode 100644
index 00000000000..d9e7fc0d6a7
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/main/java/org/gofeatureflag/openfeature/exception/InvalidOptions.kt
@@ -0,0 +1,4 @@
+package org.gofeatureflag.openfeature.exception
+
+open class InvalidOptions(): GoFeatureFlagException() {
+}
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/test/java/org/gofeatureflag/openfeature/ExampleUnitTest.kt b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/test/java/org/gofeatureflag/openfeature/ExampleUnitTest.kt
new file mode 100644
index 00000000000..341ec6f69cf
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gofeatureflag-kotlin-provider/src/test/java/org/gofeatureflag/openfeature/ExampleUnitTest.kt
@@ -0,0 +1,52 @@
+package org.gofeatureflag.openfeature
+
+import dev.openfeature.sdk.ImmutableContext
+import dev.openfeature.sdk.OpenFeatureAPI
+import dev.openfeature.sdk.Value
+import org.gofeatureflag.openfeature.bean.GoFeatureFlagOptions
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class ExampleUnitTest {
+ @Test
+ fun addition_isCorrect() {
+ assertEquals(4, 2 + 2)
+ }
+
+ @Test
+ fun xxx() {
+ val evaluationContext = ImmutableContext(
+ targetingKey = "0a23d9a5-0a8f-42c9-9f5f-4de3afd6cf99",
+ attributes = mutableMapOf(
+ "region" to Value.String("us-east-1"),
+// "email" to Value.String("john.doe@gofeatureflag.org")
+ )
+ )
+ OpenFeatureAPI.setProvider(
+ GoFeatureFlagProvider(
+ options = GoFeatureFlagOptions(
+ endpoint = "http://localhost:1031"
+ )
+ ), evaluationContext
+ )
+
+ OpenFeatureAPI.setEvaluationContext(evaluationContext)
+ val cli = OpenFeatureAPI.getClient("cli")
+ println(cli.getObjectDetails("object_key", Value.Structure(mapOf())))
+ if (cli.getBooleanValue("my-flag", false)) {
+ println("my-flag is true")
+ }
+
+ OpenFeatureAPI.shutdown()
+
+ Thread.sleep(90000)
+ println(cli.getObjectDetails("object_key", Value.Structure(mapOf())))
+
+ }
+}
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gradle.properties b/openfeature/providers/kotlin-provider/gradle.properties
new file mode 100644
index 00000000000..3c5031eb7d6
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gradle.properties
@@ -0,0 +1,23 @@
+# Project-wide Gradle settings.
+# IDE (e.g. Android Studio) users:
+# Gradle settings configured through the IDE *will override*
+# any settings specified in this file.
+# For more details on how to configure your build environment visit
+# http://www.gradle.org/docs/current/userguide/build_environment.html
+# Specifies the JVM arguments used for the daemon process.
+# The setting is particularly useful for tweaking memory settings.
+org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
+# When configured, Gradle will run in incubating parallel mode.
+# This option should only be used with decoupled projects. More details, visit
+# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
+# org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app's APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Kotlin code style for this project: "official" or "obsolete":
+kotlin.code.style=official
+# Enables namespacing of each library's R class so that its R class includes only the
+# resources declared in the library itself and none from the library's dependencies,
+# thereby reducing the size of the R class for that library
+android.nonTransitiveRClass=true
\ No newline at end of file
diff --git a/openfeature/providers/kotlin-provider/gradle/wrapper/gradle-wrapper.jar b/openfeature/providers/kotlin-provider/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 00000000000..e708b1c023e
Binary files /dev/null and b/openfeature/providers/kotlin-provider/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/openfeature/providers/kotlin-provider/gradle/wrapper/gradle-wrapper.properties b/openfeature/providers/kotlin-provider/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 00000000000..95bf7ee6414
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Fri Nov 03 22:36:18 CET 2023
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.0-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/openfeature/providers/kotlin-provider/gradlew b/openfeature/providers/kotlin-provider/gradlew
new file mode 100755
index 00000000000..4f906e0c811
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gradlew
@@ -0,0 +1,185 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+## Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+ ls=`ls -ld "$PRG"`
+ link=`expr "$ls" : '.*-> \(.*\)$'`
+ if expr "$link" : '/.*' > /dev/null; then
+ PRG="$link"
+ else
+ PRG=`dirname "$PRG"`"/$link"
+ fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+ echo "$*"
+}
+
+die () {
+ echo
+ echo "$*"
+ echo
+ exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+ CYGWIN* )
+ cygwin=true
+ ;;
+ Darwin* )
+ darwin=true
+ ;;
+ MINGW* )
+ msys=true
+ ;;
+ NONSTOP* )
+ nonstop=true
+ ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD="$JAVA_HOME/jre/sh/java"
+ else
+ JAVACMD="$JAVA_HOME/bin/java"
+ fi
+ if [ ! -x "$JAVACMD" ] ; then
+ die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+ fi
+else
+ JAVACMD="java"
+ which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+ MAX_FD_LIMIT=`ulimit -H -n`
+ if [ $? -eq 0 ] ; then
+ if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+ MAX_FD="$MAX_FD_LIMIT"
+ fi
+ ulimit -n $MAX_FD
+ if [ $? -ne 0 ] ; then
+ warn "Could not set maximum file descriptor limit: $MAX_FD"
+ fi
+ else
+ warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+ fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+ GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+ APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+ CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
+ JAVACMD=`cygpath --unix "$JAVACMD"`
+
+ # We build the pattern for arguments to be converted via cygpath
+ ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+ SEP=""
+ for dir in $ROOTDIRSRAW ; do
+ ROOTDIRS="$ROOTDIRS$SEP$dir"
+ SEP="|"
+ done
+ OURCYGPATTERN="(^($ROOTDIRS))"
+ # Add a user-defined pattern to the cygpath arguments
+ if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+ OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+ fi
+ # Now convert the arguments - kludge to limit ourselves to /bin/sh
+ i=0
+ for arg in "$@" ; do
+ CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+ CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option
+
+ if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition
+ eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+ else
+ eval `echo args$i`="\"$arg\""
+ fi
+ i=`expr $i + 1`
+ done
+ case $i in
+ 0) set -- ;;
+ 1) set -- "$args0" ;;
+ 2) set -- "$args0" "$args1" ;;
+ 3) set -- "$args0" "$args1" "$args2" ;;
+ 4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+ 5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+ 6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+ 7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+ 8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+ 9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+ esac
+fi
+
+# Escape application args
+save () {
+ for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+ echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"
diff --git a/openfeature/providers/kotlin-provider/gradlew.bat b/openfeature/providers/kotlin-provider/gradlew.bat
new file mode 100644
index 00000000000..ac1b06f9382
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/gradlew.bat
@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/openfeature/providers/kotlin-provider/settings.gradle.kts b/openfeature/providers/kotlin-provider/settings.gradle.kts
new file mode 100644
index 00000000000..8da0565dac2
--- /dev/null
+++ b/openfeature/providers/kotlin-provider/settings.gradle.kts
@@ -0,0 +1,17 @@
+pluginManagement {
+ repositories {
+ google()
+ mavenCentral()
+ gradlePluginPortal()
+ }
+}
+dependencyResolutionManagement {
+ repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+ repositories {
+ google()
+ mavenCentral()
+ }
+}
+
+rootProject.name = "go-feature-flag-kotlin-provider"
+include(":gofeatureflag-kotlin-provider")