Kotlin

Native Kotlin SDK for Android/JVM apps.

Overview

The Kotlin SDK provides realtime flag updates, polling fallback, identity targeting, and telemetry with one client object: TruflagClient.

Get started

Install

KKOTLIN

dependencies {
  implementation("com.truflag:truflag-android-client-sdk:1.0.2")
}

Configure

apiKey is required. If no user is passed, the SDK starts anonymous automatically.

KKOTLIN

import com.truflag.sdk.TruflagClient
 
val client = TruflagClient()
 
client.configure(
  apiKey = BuildConfig.TRUFLAG_CLIENT_KEY,
  userId = "user-123",
  userAttributes = mapOf(
    "plan" to "pro",
    "country" to "US",
  ),
)

SDK API overview

Full configure surface for Kotlin.

KKOTLIN

suspend fun configure(
  apiKey: String,
  userId: String? = null,
  userAttributes: Map<String, Any?>? = null,
  baseUrl: String = "https://sdk.truflag.com",
  streamUrl: String = "wss://stream.sdk.truflag.com",
  streamEnabled: Boolean = true,
  logLevel: TruflagLogLevel = TruflagLogLevel.DEBUG,
  cacheTtlMs: Long = 300_000,
  pollingIntervalMs: Long = 60_000,
  requestTimeoutMs: Long = 6_000,
  telemetryEnabled: Boolean = true,
  telemetryFlushIntervalMs: Long = 10_000,
  telemetryBatchSize: Int = 50,
  logger: TruflagLogger? = null,
  fetchFn: TruflagFetchFn? = null,
  storage: TruflagStorage? = null,
): Unit
 
data class TruflagConfigureOptions(
  val apiKey: String,
  val user: TruflagUser? = null,
  val baseUrl: String = "https://sdk.truflag.com",
  val streamUrl: String = "wss://stream.sdk.truflag.com",
  val streamEnabled: Boolean = true,
  val logLevel: TruflagLogLevel = TruflagLogLevel.DEBUG,
  val cacheTtlMs: Long = 300_000,
  val pollingIntervalMs: Long = 60_000,
  val requestTimeoutMs: Long = 6_000,
  val telemetryEnabled: Boolean = true,
  val telemetryFlushIntervalMs: Long = 10_000,
  val telemetryBatchSize: Int = 50,
  val logger: TruflagLogger? = null,
  val fetchFn: TruflagFetchFn? = null,
  val storage: TruflagStorage? = null,
)

Identity

KKOTLIN

client.login(
  userId = "user-456",
  attributes = mapOf("plan" to "enterprise"),
)
 
client.setAttributes(
  mapOf("plan" to "enterprise", "region" to "us-east-1"),
)
 
client.logout() // switches to anonymous user and refreshes

Flag reads

Use one read method: getFlag(key, fallback).

KKOTLIN

// One-off read with fallback:
val enabled = client.getFlag("my-flag", false)
val variant = client.getFlag("checkout-variant", "control")
val config = client.getFlag("checkout-config", emptyMap<String, Any?>())
 
// Optional metadata
val payload = client.getFlagPayload("my-flag")

Events

KKOTLIN

client.track(
  eventName = "checkout_completed",
  properties = mapOf(
    "source" to "android",
    "value" to 99.95,
    "context" to mapOf("screen" to "checkout"),
    "items" to listOf("sku_1", "sku_2"),
  ),
)
 
client.expose(
  flagKey = "my-flag",
)

Reactive updates

state() emits when flags/identity/diagnostics change, including websocket-driven updates.

KKOTLIN

// Reactive UI pattern:
scope.launch {
  client.state().collect {
    val next = client.getFlag("my-flag", false)
    // update UI state here
  }
}

Troubleshooting

Flags always return fallback

Confirm client.isReady() is true and the flag key exists in the environment tied to your apiKey.

No realtime updates

Verify streamEnabled = true and a validstreamUrl. Polling fallback remains active if stream connectivity drops.