Getting Started With Kotlin UI Kit

Step-by-step guide to integrate the CometChat Kotlin UI Kit with XML Views into your Android app.

AI Integration Quick Reference

Field	Value
Package	com.cometchat:chat-uikit-kotlin
UI Layer	Kotlin + XML Views (View Binding)
Init	CometChatUIKit.init(context, UIKitSettings, callback) — must resolve before login()
Login	CometChatUIKit.login("UID", callback) — must resolve before rendering components
Order	init() → login() → render. Breaking this order = blank screen
Auth Key	Dev/testing only. Use Auth Token in production
Calling	Optional. Add com.cometchat:calls-sdk-android to enable voice/video
Min SDK	Android 9.0 (API 28)

This guide walks you through integrating the CometChat Kotlin UI Kit into an Android app using XML Views and View Binding. By the end you’ll have a working chat UI.

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Prerequisites

You need three things from the CometChat Dashboard:

Credential	Where to find it
App ID	Dashboard → Your App → Credentials
Auth Key	Dashboard → Your App → Credentials
Region	Dashboard → Your App → Credentials (e.g. us, eu, in)

You also need:

• Android Studio installed
• An Android emulator or physical device running Android 9.0 (API 28) or higher
• Kotlin configured in your project
• Gradle plugin 8.0+ with Kotlin DSL

Auth Key is for development only. In production, generate Auth Tokens server-side via the REST API and use loginWithAuthToken(). Never ship Auth Keys in client code.

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Step 1 — Create an Android Project

1. Open Android Studio and start a new project.
2. Choose Empty Activity as the project template.
3. Select Kotlin as the language.
4. Set minimum API level to 28 or higher.

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Step 2 — Install Dependencies

Add the CometChat Repository

Add the CometChat Maven repository to your settings.gradle.kts:

settings.gradle.kts

dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        google()
        mavenCentral()
        maven("https://dl.cloudsmith.io/public/cometchat/cometchat/maven/")
    }
}

Add Dependencies

Open your app-level build.gradle.kts and enable View Binding, then add the dependencies:

build.gradle.kts

android {
    // ...
    buildFeatures {
        viewBinding = true
    }
    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_11
        targetCompatibility = JavaVersion.VERSION_11
    }
    kotlinOptions {
        jvmTarget = "11"
    }
}

dependencies {
    // CometChat Kotlin UI Kit
    implementation("com.cometchat:chat-uikit-kotlin:latest")

    // (Optional) Voice/video calling
    implementation("com.cometchat:calls-sdk-android:latest")
}

Add AndroidX Support

Verify this line is present in gradle.properties:

gradle.properties

android.enableJetifier=true

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Step 3 — Initialize and Login

Create your MainActivity.kt with the CometChat initialization and login flow:

MainActivity.kt

import android.os.Bundle
import android.util.Log
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import com.cometchat.chat.core.CometChat
import com.cometchat.chat.exceptions.CometChatException
import com.cometchat.chat.models.User
import com.cometchat.uikit.core.CometChatUIKit
import com.cometchat.uikit.core.UIKitSettings

class MainActivity : AppCompatActivity() {

    private val TAG = "MainActivity"

    private val appID = "APP_ID"       // Replace with your App ID
    private val region = "REGION"      // Replace with your App Region
    private val authKey = "AUTH_KEY"   // Replace with your Auth Key

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()

        val uiKitSettings = UIKitSettings.UIKitSettingsBuilder()
            .setRegion(region)
            .setAppId(appID)
            .setAuthKey(authKey)
            .subscribePresenceForAllUsers()
            .build()

        CometChatUIKit.init(this, uiKitSettings, object : CometChat.CallbackListener<String?>() {
            override fun onSuccess(s: String?) {
                Log.d(TAG, "Initialization completed successfully")
                loginUser()
            }

            override fun onError(e: CometChatException?) {
                Log.e(TAG, "Initialization failed: ${e?.message}")
            }
        })
    }

    private fun loginUser() {
        CometChatUIKit.login("cometchat-uid-1", object : CometChat.CallbackListener<User>() {
            override fun onSuccess(user: User) {
                Log.d(TAG, "Login successful: ${user.uid}")

                // Navigate to your chat screen after login
                // startActivity(Intent(this@MainActivity, ConversationActivity::class.java))
            }

            override fun onError(e: CometChatException) {
                Log.e(TAG, "Login failed: ${e.message}")
            }
        })
    }
}

init() must resolve before you call login(). Calling login() before init completes will fail silently.

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Step 4 — Choose a Chat Experience

Integrate a conversation view that suits your app’s UX. Each option below includes a step-by-step guide.

Conversation List + Message View

Sequential navigation — conversation list as the entry point, tap a conversation to open a full-screen message view.

Build Conversation List + Message View

Step-by-step guide to build this layout with Kotlin XML Views

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One-to-One / Group Chat

Single chat window — no sidebar. Loads a specific user or group chat directly. Ideal for support chat, direct messages, or notification-driven flows.

Build One-to-One / Group Chat

Step-by-step guide to build this layout

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Tab-Based Chat

Bottom navigation with tabs for Chats, Calls, Users, and Settings.

Build Tab-Based Chat

Step-by-step guide to build this layout

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Next Steps

Components Overview

Browse all available UI Kit components

Theming

Customize colors, fonts, and styles

Core Features

Chat features included out of the box

Troubleshooting

Common issues and fixes