This document guides how to use the Kakao SDK for Android("Android SDK") provided by the Kakao Developers.

• Android Studio 3.6.1 or higher
• API 23: Android 6.0 (Marshmallow) or higher

The Android SDK uses the following libraries that are automatically installed when installing the Android SDK.

• Android SDK: Retrofit, OkHttp
• ReactiveX Android SDK: RxJava3 + Android SDK (Retrofit, OkHttp)

Set the Android app information in [App] > [Platform key] > [Native app key] on the app management page. For details, see Native app key.

A key hash is a hashed value of the certificate’s certificate fingerprints, used to determine whether an app is malicious. When the Kakao API is invoked, the Kakao API server checks whether the key hash added to the request header matches the value registered on the Kakao platform. There are two types of key hashes: a debug key hash and a release key hash.

• Debug key hash: A value hashed from the debug certificate automatically generated by Android Studio according to the development environment when the project is first created or debugged.
• Release key hash: A value hashed from the release certificate created for distributing the app to an app store.

Check both the debug and release key hash values using the methods below, then register them in [App] > [Platform key] > [Native app key] on the app management page. For details, see Native app key.

To get key hashes using Terminal, Keytool program, key and certificate management tool are required. On Windows, download OpenSSL for Windows libraries is required. On Mac, Keytool is installed.

Run the command in Command Prompt according to the operating system.

keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore -storepass android -keypass android | openssl sha1 -binary | openssl base64

keytool -exportcert -alias <RELEASE_KEY_ALIAS> -keystore <RELEASE_KEY_PATH> | openssl sha1 -binary | openssl base64

Call the getKeyHash() method provided in Utility through the Android SDK.

import com.kakao.sdk.common.util.Utility

var keyHash = Utility.getKeyHash(this)

With Google Play App Signing, use the SHA-1 certificate fingerprint obtained on the Google Play Console, not generating a Release key hash on the Terminal. Refer to Play Console Help > Use Play App Signing for more details.

In the Google Play Console, select [Release Management] > [App Signing], and then copy the value of SHA-1 certificate fingerprint. Refer to Use Play App Signing.

keytool -printcert -file ./deployment_cert.der

Run the following command in Terminal with the SHA-1 certificate fingerprint value obtained.

echo "{SHA-1_CERTIFICATE_FINGERPRINT}" | xxd -r -p | openssl base64

Kakao Developers provides a sample app that allows you to quickly check the main features of the Android SDK. With the sample app, you can directly test SDK features such as Kakao Login and Kakao Talk Share, and review sample implementation code.

This section describes how to run the Android SDK sample app.

1. Download the Android SDK sample app from Download.
2. Refer to Key hash to generate the debug key hash for the sample app project.
3. Register the generated key hash in [Android SDK sample app] on the Account settings page.
   • The key hash registered for the sample app is used to validate sample app requests.
   • If the sample app key hash is missing or incorrectly registered, a KOE009 or 401 error occurs.
4. You can run the sample app to test the key features of the Android SDK and review the implementation example code.

Allow internet permission to communicate with the Kakao Sever through the Kakao APIs.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.sample">

    <!-- Allow Internet permission -->
    <uses-permission android:name="android.permission.INTERNET" />

    <application
    android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
    ...

Screenshot of allowing internet permission in Android Studio

To enable shrinking, obfuscation, and optimization when building the release version of the app, add the following codes in the ProGuard rules file to exclude the Kakao SDK from shrinking and obfuscation.

-keep class com.kakao.sdk.**.model.* { <fields>; }

# https://github.com/square/okhttp/pull/6792
-dontwarn org.bouncycastle.jsse.**
-dontwarn org.conscrypt.*
-dontwarn org.openjsse.**

# refrofit2 (with r8 full mode)
-if interface * { @retrofit2.http.* <methods>; }
-keep,allowobfuscation interface <1>
-keep,allowobfuscation,allowshrinking class kotlin.coroutines.Continuation
-if interface * { @retrofit2.http.* public *** *(...); }
-keep,allowoptimization,allowshrinking,allowobfuscation class <3>
-keep,allowobfuscation,allowshrinking class retrofit2.Response

Set Gradle by declaring a Maven repository to sync the project with the Android SDK. Depending on the version of Android Studio, the file to declare repositories is different. Refer to Dependency management in Gradle for more details.

dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        google()
        mavenCentral()
        maven { url = java.net.URI("https://devrepo.kakao.com/nexus/content/groups/public/") }
    }
}

Add the required modules to the build.gradle.kts file at the module level. You can add either all modules or only the required ones.

dependencies {
  implementation("com.kakao.sdk:v2-all:${LATEST_VERSION}") // Add all modules (Available in 2.11.0 or higher)
  implementation("com.kakao.sdk:v2-user:${LATEST_VERSION}") // Module for the Kakao Login APIs
  implementation("com.kakao.sdk:v2-share:${LATEST_VERSION}") // Module for the Kakao Talk Share APIs
  implementation("com.kakao.sdk:v2-talk:${LATEST_VERSION}") // Module for the Kakao Talk Channel, Kakao Talk Social, Kakao Talk Message APIs
  implementation("com.kakao.sdk:v2-friend:${LATEST_VERSION}") // Module for the picker APIs
  implementation("com.kakao.sdk:v2-navi:${LATEST_VERSION}") // Module for the Kakao Navi APIs
  implementation("com.kakao.sdk:v2-cert:${LATEST_VERSION}") // Module for the Kakao Certification APIs
}

To use the Android SDK, install and then initialize it by including the app’s Native app key in the init() method. The Native app key can be found in [App] > [Platform key] > [Native app key] on the app management page.

If you are using a class that extends Application, you can initialize it as shown below.

class GlobalApplication : Application() {
  override fun onCreate() {
    super.onCreate()
    // Other codes for initialization

    // Initialize Android SDK
    KakaoSdk.init(this, "${YOUR_NATIVE_APP_KEY}")
  }
}

You must also set the name of the class that performs Kakao SDK initialization in the application of AndroidManifest.xml. In the example above, initialization was done in the GlobalApplication class, so add the same name in the settings as shown below.

<application
    <!-- android:name setting -->
    android:name=".GlobalApplication"
    <!-- ... -->
>

The modules and main features of Android SDK are below.

Some modules in the Kakao SDK are dependent on another module. Each subordinate module is automatically added together.

Kakao SDK module dependency tree