Add Firebase push notification support and Android Mattermost integration

- Android: MainActivity, AppLifecycleTracker, Firebase Messaging Service - Android: Notification handlers (dismiss, reply, receipt delivery) - Android: Custom push notification helper and database support - Android: Drawable resources for notification actions - Android: Mipmap resources with foreground/background/round icons - iOS: Push notification service support - Flutter: Push notification background and foreground services - Web/Windows: Generated plugin registrant updates - Config: Added google-services.json for Firebase
2026-03-21 15:06:19 +09:00 · 2026-03-21 15:06:19 +09:00 · 9a39917a2c
commit 9a39917a2c
parent 73375477ba
67 changed files with 2469 additions and 101 deletions
--- a/android/app/build.gradle.kts
+++ b/android/app/build.gradle.kts
@ -1,12 +1,14 @@
 plugins {
    id("com.android.application")
    id("kotlin-android")
+    id("kotlin-kapt")
    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
    id("dev.flutter.flutter-gradle-plugin")
+    id("com.google.gms.google-services")
 }

 android {
-    namespace = "com.nomadcode.nomadcode"
+    namespace = "com.tokilabs.mattermost"
    compileSdk = flutter.compileSdkVersion
    ndkVersion = flutter.ndkVersion

@ -21,7 +23,7 @@ android {

    defaultConfig {
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
-        applicationId = "com.nomadcode.nomadcode"
+        applicationId = "com.tokilabs.mattermost"
        // You can update the following values to match your application needs.
        // For more information, see: https://flutter.dev/to/review-gradle-config.
        minSdk = flutter.minSdkVersion
@ -42,3 +44,27 @@ android {
 flutter {
    source = "../.."
 }
+
+dependencies {
+    // Firebase BOM (버전 통합 관리)
+    implementation(platform("com.google.firebase:firebase-bom:33.7.0"))
+    implementation("com.google.firebase:firebase-messaging")
+
+    // JWT 서명 검증 (mattermost와 동일 버전)
+    implementation("io.jsonwebtoken:jjwt-api:0.12.5")
+    runtimeOnly("io.jsonwebtoken:jjwt-impl:0.12.5")
+    runtimeOnly("io.jsonwebtoken:jjwt-orgjson:0.12.5") {
+        exclude(group = "org.json", module = "json")
+    }
+
+    // HTTP 클라이언트
+    implementation("com.squareup.okhttp3:okhttp:4.12.0")
+
+    // Kotlin Coroutines
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.7.3")
+
+    // Room DB (로컬 캐시용)
+    implementation("androidx.room:room-runtime:2.6.1")
+    implementation("androidx.room:room-ktx:2.6.1")
+    kapt("androidx.room:room-compiler:2.6.1")
+}
--- a/android/app/google-services.json
+++ b/android/app/google-services.json
@ -0,0 +1,29 @@
+{
+  "project_info": {
+    "project_number": "1047648748539",
+    "project_id": "mattermost-6ac08",
+    "storage_bucket": "mattermost-6ac08.firebasestorage.app"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:1047648748539:android:818bf70bfbb3f9d070415e",
+        "android_client_info": {
+          "package_name": "com.tokilabs.mattermost"
+        }
+      },
+      "oauth_client": [],
+      "api_key": [
+        {
+          "current_key": "AIzaSyAW6j_oPl9MVcm93qS3JgaEPD5ywp-TzZ0"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": []
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@ -1,8 +1,14 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+    <uses-permission android:name="android.permission.VIBRATE"/>
+    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
+
    <application
        android:label="nomadcode"
-        android:name="${applicationName}"
-        android:icon="@mipmap/ic_launcher">
+        android:name=".MainApplication"
+        android:icon="@mipmap/ic_launcher"
+        android:roundIcon="@mipmap/ic_launcher_round">
        <activity
            android:name=".MainActivity"
            android:exported="true"
@ -30,6 +36,27 @@
        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
+
+        <!-- Firebase Messaging Service -->
+        <service
+            android:name=".MattermostFirebaseMessagingService"
+            android:exported="false">
+            <intent-filter>
+                <action android:name="com.google.firebase.MESSAGING_EVENT"/>
+            </intent-filter>
+        </service>
+
+        <!-- 알림 삭제 서비스 -->
+        <service
+            android:name=".NotificationDismissService"
+            android:enabled="true"
+            android:exported="false" />
+
+        <!-- 알림 답장 브로드캐스트 리시버 -->
+        <receiver
+            android:name=".NotificationReplyBroadcastReceiver"
+            android:enabled="true"
+            android:exported="false" />
    </application>
    <!-- Required to query activities that can process text, see:
         https://developer.android.com/training/package-visibility and
--- a/android/app/src/main/java/com/tokilabs/mattermost/AppLifecycleTracker.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/AppLifecycleTracker.kt
@ -0,0 +1,35 @@
+package com.tokilabs.mattermost
+
+import android.app.Activity
+import android.app.Application
+import android.os.Bundle
+
+/**
+ * 앱 포그라운드/백그라운드 상태 추적.
+ * CustomPushNotification의 mAppLifecycleFacade.isAppVisible() 대응.
+ */
+object AppLifecycleTracker : Application.ActivityLifecycleCallbacks {
+    var isInForeground = false
+        private set
+
+    private var activeActivities = 0
+
+    override fun onActivityStarted(activity: Activity) {
+        activeActivities++
+        isInForeground = true
+    }
+
+    override fun onActivityStopped(activity: Activity) {
+        activeActivities--
+        if (activeActivities <= 0) {
+            activeActivities = 0
+            isInForeground = false
+        }
+    }
+
+    override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {}
+    override fun onActivityResumed(activity: Activity) {}
+    override fun onActivityPaused(activity: Activity) {}
+    override fun onActivitySaveInstanceState(activity: Activity, outState: Bundle) {}
+    override fun onActivityDestroyed(activity: Activity) {}
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/MainActivity.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/MainActivity.kt
@ -0,0 +1,102 @@
+package com.tokilabs.mattermost
+
+import android.os.Bundle
+import com.tokilabs.mattermost.helpers.DatabaseHelper
+import com.tokilabs.mattermost.helpers.Network
+import io.flutter.embedding.android.FlutterActivity
+import io.flutter.embedding.engine.FlutterEngine
+import io.flutter.embedding.engine.FlutterEngineCache
+import io.flutter.plugin.common.EventChannel
+import io.flutter.plugin.common.MethodChannel
+
+/**
+ * Flutter 메인 액티비티.
+ * - Flutter EventChannel 등록 (네이티브 알림 이벤트 → Dart 전달)
+ * - Flutter MethodChannel 등록 (Dart → 네이티브 토큰 저장 등)
+ * - FlutterEngineCache에 엔진 등록 (백그라운드에서 Flutter 초기화 여부 확인용)
+ */
+class MainActivity : FlutterActivity() {
+
+    companion object {
+        const val NOTIFICATION_EVENT_CHANNEL = "com.tokilabs.mattermost/notifications"
+        const val NOTIFICATION_METHOD_CHANNEL = "com.tokilabs.mattermost/notification_actions"
+    }
+
+    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
+        super.configureFlutterEngine(flutterEngine)
+
+        // FlutterEngineCache에 등록 → 백그라운드 서비스에서 초기화 여부 확인 가능
+        FlutterEngineCache.getInstance()
+            .put(MattermostFirebaseMessagingService.FLUTTER_ENGINE_ID, flutterEngine)
+
+        // EventChannel: 네이티브 알림 → Dart
+        EventChannel(flutterEngine.dartExecutor.binaryMessenger, NOTIFICATION_EVENT_CHANNEL)
+            .setStreamHandler(object : EventChannel.StreamHandler {
+                override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
+                    MattermostFirebaseMessagingService.eventSink = events
+                }
+                override fun onCancel(arguments: Any?) {
+                    MattermostFirebaseMessagingService.eventSink = null
+                }
+            })
+
+        // MethodChannel: Dart → 네이티브 (토큰 저장, 채널 클리어 등)
+        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, NOTIFICATION_METHOD_CHANNEL)
+            .setMethodCallHandler { call, result ->
+                when (call.method) {
+                    "saveDeviceToken" -> {
+                        val token = call.argument<String>("token")
+                        if (token != null) {
+                            DatabaseHelper.getInstance()?.saveDeviceToken(token)
+                            result.success(null)
+                        } else {
+                            result.error("INVALID_ARG", "token is null", null)
+                        }
+                    }
+                    "getDeviceToken" -> {
+                        result.success(DatabaseHelper.getInstance()?.getDeviceToken())
+                    }
+                    // 로그인 성공 시 Dart에서 호출 → 서버 URL + 인증 토큰 저장
+                    "setAuthToken" -> {
+                        val serverUrl = call.argument<String>("serverUrl")
+                        val token = call.argument<String>("token")
+                        val identifier = call.argument<String>("identifier")
+                        if (serverUrl != null && token != null) {
+                            Network.setToken(serverUrl, token)
+                            DatabaseHelper.getInstance()?.saveServerUrl(serverUrl, identifier)
+                            result.success(null)
+                        } else {
+                            result.error("INVALID_ARG", "serverUrl or token is null", null)
+                        }
+                    }
+                    // 로그아웃 시 토큰 제거
+                    "clearAuthToken" -> {
+                        val serverUrl = call.argument<String>("serverUrl")
+                        if (serverUrl != null) {
+                            Network.clearToken(serverUrl)
+                            result.success(null)
+                        } else {
+                            result.error("INVALID_ARG", "serverUrl is null", null)
+                        }
+                    }
+                    else -> result.notImplemented()
+                }
+            }
+    }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        // 알림 탭으로 앱 진입 시 Intent 데이터를 Flutter로 전달
+        intent?.extras?.let { extras ->
+            val data = mutableMapOf<String, Any?>()
+            for (key in extras.keySet()) {
+                data[key] = extras.get(key)
+            }
+            if (data.isNotEmpty()) {
+                MattermostFirebaseMessagingService.eventSink?.success(
+                    data + mapOf("type" to (data["type"] ?: "opened"), "userInteraction" to true)
+                )
+            }
+        }
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/MainApplication.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/MainApplication.kt
@ -0,0 +1,27 @@
+package com.tokilabs.mattermost
+
+import android.app.Application
+import com.tokilabs.mattermost.helpers.CustomPushNotificationHelper
+import com.tokilabs.mattermost.helpers.DatabaseHelper
+
+/**
+ * 앱 Application 클래스.
+ * - DatabaseHelper 초기화
+ * - 알림 채널 생성
+ * - AppLifecycleTracker 등록
+ */
+class MainApplication : Application() {
+
+    override fun onCreate() {
+        super.onCreate()
+
+        // 앱 생명주기 추적 (포그라운드/백그라운드 감지)
+        registerActivityLifecycleCallbacks(AppLifecycleTracker)
+
+        // DB 초기화
+        DatabaseHelper.init(this)
+
+        // Android 8+ 알림 채널 생성
+        CustomPushNotificationHelper.createNotificationChannels(this)
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/MattermostFirebaseMessagingService.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/MattermostFirebaseMessagingService.kt
@ -0,0 +1,231 @@
+package com.tokilabs.mattermost
+
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import android.util.Log
+import androidx.core.app.NotificationCompat
+import com.google.firebase.messaging.FirebaseMessagingService
+import com.google.firebase.messaging.RemoteMessage
+import com.tokilabs.mattermost.helpers.CustomPushNotificationHelper
+import com.tokilabs.mattermost.helpers.Network
+import com.tokilabs.mattermost.helpers.NotificationHelper
+import com.tokilabs.mattermost.helpers.PushNotificationDataHelper
+import io.flutter.embedding.engine.FlutterEngineCache
+import io.flutter.plugin.common.EventChannel
+import kotlinx.coroutines.DelicateCoroutinesApi
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.launch
+
+/**
+ * Firebase FCM 메시지 수신 및 처리.
+ * mattermost-mobile의 CustomPushNotification.kt 이식 버전.
+ * RN 브릿지(WIX PushNotification) → FirebaseMessagingService + Flutter EventChannel 으로 교체.
+ */
+class MattermostFirebaseMessagingService : FirebaseMessagingService() {
+
+    private val dataHelper by lazy { PushNotificationDataHelper(this) }
+
+    companion object {
+        private const val TAG = "MattermostFCM"
+        const val FLUTTER_ENGINE_ID = "main_engine"
+        const val NOTIFICATION_CHANNEL = "com.tokilabs.mattermost/notifications"
+
+        // Flutter EventChannel sink (MainActivity에서 설정)
+        var eventSink: EventChannel.EventSink? = null
+    }
+
+    /**
+     * FCM 토큰 갱신 시 호출.
+     * Flutter 쪽으로 새 토큰 전달.
+     */
+    override fun onNewToken(token: String) {
+        super.onNewToken(token)
+        Log.i(TAG, "New FCM token: $token")
+        // Flutter EventChannel이 준비된 경우 토큰 전달
+        eventSink?.success(mapOf("type" to "token_refresh", "token" to token))
+    }
+
+    /**
+     * FCM 메시지 수신 시 호출.
+     * CustomPushNotification.onReceived() 대응.
+     */
+    @OptIn(DelicateCoroutinesApi::class)
+    override fun onMessageReceived(remoteMessage: RemoteMessage) {
+        super.onMessageReceived(remoteMessage)
+
+        val data = remoteMessage.data
+        if (data.isEmpty()) return
+
+        val bundle = Bundle().apply {
+            data.forEach { (k, v) -> putString(k, v) }
+        }
+
+        val type = bundle.getString("type")
+        val ackId = bundle.getString("ack_id")
+        val postId = bundle.getString("post_id")
+        val channelId = bundle.getString("channel_id")
+        val signature = bundle.getString("signature")
+        val isIdLoaded = bundle.getString("id_loaded") == "true"
+        val notificationId = NotificationHelper.getNotificationId(bundle)
+        val serverUrl = bundle.getString("server_url")
+
+        Log.i(TAG, "onMessageReceived type=$type channelId=$channelId ackId=$ackId")
+
+        GlobalScope.launch {
+            try {
+                handlePushNotificationInCoroutine(
+                    serverUrl, type, channelId, ackId,
+                    isIdLoaded, notificationId, postId, signature, bundle
+                )
+            } catch (e: Exception) {
+                Log.e(TAG, "Error handling notification: ${e.message}")
+                e.printStackTrace()
+            }
+        }
+    }
+
+    /**
+     * 비동기 알림 처리 코루틴.
+     * CustomPushNotification.handlePushNotificationInCoroutine() 대응.
+     */
+    private suspend fun handlePushNotificationInCoroutine(
+        serverUrl: String?,
+        type: String?,
+        channelId: String?,
+        ackId: String?,
+        isIdLoaded: Boolean,
+        notificationId: Int,
+        postId: String?,
+        signature: String?,
+        bundle: Bundle
+    ) {
+        var currentBundle = bundle
+
+        // ACK 전송
+        if (ackId != null && serverUrl != null) {
+            val response = ReceiptDelivery.send(ackId, serverUrl, postId, type, isIdLoaded)
+            if (isIdLoaded && response != null) {
+                if (!currentBundle.containsKey("server_url")) {
+                    response.putString("server_url", serverUrl)
+                }
+                currentBundle.putAll(response)
+            }
+        }
+
+        // JWT 서명 검증
+        if (!CustomPushNotificationHelper.verifySignature(this, signature, serverUrl, ackId)) {
+            Log.i(TAG, "Notification skipped: signature verification failed")
+            return
+        }
+
+        finishProcessingNotification(serverUrl, type, channelId, notificationId, currentBundle)
+    }
+
+    /**
+     * 알림 최종 처리.
+     * CustomPushNotification.finishProcessingNotification() 대응.
+     */
+    private suspend fun finishProcessingNotification(
+        serverUrl: String?,
+        type: String?,
+        channelId: String?,
+        notificationId: Int,
+        bundle: Bundle
+    ) {
+        var currentBundle = bundle
+        val isFlutterRunning = isFlutterEngineRunning()
+
+        when (type) {
+            CustomPushNotificationHelper.PUSH_TYPE_MESSAGE,
+            CustomPushNotificationHelper.PUSH_TYPE_SESSION -> {
+                // 앱이 포그라운드가 아닐 때 시스템 알림 표시
+                if (!isFlutterRunning || !isAppInForeground()) {
+                    var createSummary = type == CustomPushNotificationHelper.PUSH_TYPE_MESSAGE
+
+                    if (type == CustomPushNotificationHelper.PUSH_TYPE_MESSAGE && channelId != null) {
+                        serverUrl?.let {
+                            val notificationResult = dataHelper.fetchAndStoreDataForPushNotification(currentBundle, isFlutterRunning)
+                            notificationResult?.let { result ->
+                                currentBundle.putBundle("data", result)
+                            }
+                        }
+                        createSummary = NotificationHelper.addNotificationToPreferences(this, notificationId, currentBundle)
+                    }
+
+                    buildAndPostNotification(notificationId, createSummary, currentBundle)
+                }
+            }
+            CustomPushNotificationHelper.PUSH_TYPE_CLEAR ->
+                NotificationHelper.clearChannelOrThreadNotifications(this, currentBundle)
+        }
+
+        // Flutter가 실행 중이면 EventChannel로 알림 데이터 전달
+        if (isFlutterRunning) {
+            notifyReceivedToFlutter(currentBundle)
+        }
+    }
+
+    /**
+     * Flutter EventChannel로 알림 이벤트 전송.
+     * CustomPushNotification.notifyReceivedToJS() 대응.
+     */
+    private fun notifyReceivedToFlutter(bundle: Bundle) {
+        val data = bundleToMap(bundle)
+        Log.i(TAG, "Sending notification event to Flutter: type=${data["type"]}")
+        eventSink?.success(data)
+    }
+
+    /**
+     * 시스템 알림 빌드 및 표시.
+     */
+    private fun buildAndPostNotification(notificationId: Int, createSummary: Boolean, bundle: Bundle) {
+        val intent = Intent(this, MainActivity::class.java).apply {
+            flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TOP
+            putExtras(bundle)
+        }
+        val pendingIntent = PendingIntent.getActivity(
+            this, notificationId, intent,
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
+        )
+
+        val notification = CustomPushNotificationHelper.createNotificationBuilder(this, pendingIntent, bundle, false).build()
+
+        if (createSummary) {
+            val summary = CustomPushNotificationHelper.createNotificationBuilder(this, pendingIntent, bundle, true).build()
+            NotificationHelper.postNotification(this, summary, notificationId + 1)
+        }
+        NotificationHelper.postNotification(this, notification, notificationId)
+    }
+
+    /**
+     * Flutter 엔진 실행 여부 확인.
+     * CustomPushNotification의 isReactInitialized() 대응.
+     */
+    private fun isFlutterEngineRunning(): Boolean {
+        return FlutterEngineCache.getInstance().contains(FLUTTER_ENGINE_ID)
+    }
+
+    /**
+     * 앱 포그라운드 여부 확인.
+     */
+    private fun isAppInForeground(): Boolean {
+        return AppLifecycleTracker.isInForeground
+    }
+
+    /**
+     * Bundle → Map 변환 (EventChannel 전송용).
+     */
+    private fun bundleToMap(bundle: Bundle): Map<String, Any?> {
+        val map = mutableMapOf<String, Any?>()
+        for (key in bundle.keySet()) {
+            val value = bundle.get(key)
+            map[key] = when (value) {
+                is Bundle -> bundleToMap(value)
+                else -> value
+            }
+        }
+        return map
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/NotificationDismissService.java
+++ b/android/app/src/main/java/com/tokilabs/mattermost/NotificationDismissService.java
@ -0,0 +1,40 @@
+package com.tokilabs.mattermost;
+
+import android.app.IntentService;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.util.Log;
+
+import com.tokilabs.mattermost.helpers.NotificationHelper;
+
+/**
+ * 사용자가 알림을 스와이프(해제)할 때 처리.
+ * mattermost-mobile의 NotificationDismissService.java 이식 버전.
+ * com.wix.reactnativenotifications.core.NotificationIntentAdapter
+ *   → 표준 Intent extras 방식으로 교체.
+ */
+@SuppressWarnings("deprecation")
+public class NotificationDismissService extends IntentService {
+
+    private static final String TAG = "NotifDismissService";
+    private static final String PUSH_NOTIFICATION_EXTRA_NAME = "pushNotification";
+
+    public NotificationDismissService() {
+        super("notificationDismissService");
+    }
+
+    @Override
+    protected void onHandleIntent(Intent intent) {
+        if (intent == null) return;
+
+        final Context context = getApplicationContext();
+        // WIX NotificationIntentAdapter 대신 표준 extras 방식으로 번들 추출
+        final Bundle bundle = intent.getBundleExtra(PUSH_NOTIFICATION_EXTRA_NAME);
+
+        if (bundle != null) {
+            NotificationHelper.INSTANCE.dismissNotification(context, bundle);
+            Log.i(TAG, "Dismiss notification id=" + NotificationHelper.INSTANCE.getNotificationId(bundle));
+        }
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/NotificationReplyBroadcastReceiver.java
+++ b/android/app/src/main/java/com/tokilabs/mattermost/NotificationReplyBroadcastReceiver.java
@ -0,0 +1,152 @@
+package com.tokilabs.mattermost;
+
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.app.RemoteInput;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.util.Log;
+
+import androidx.annotation.NonNull;
+import androidx.core.app.NotificationCompat;
+import androidx.core.app.Person;
+
+import com.tokilabs.mattermost.helpers.CustomPushNotificationHelper;
+import com.tokilabs.mattermost.helpers.Network;
+import com.tokilabs.mattermost.helpers.NotificationHelper;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+/**
+ * 알림에서 직접 답장(인라인 리플) 처리.
+ * mattermost-mobile의 NotificationReplyBroadcastReceiver.java 이식 버전.
+ * com.facebook.react.bridge.* + Network.post() → OkHttp 직접 사용으로 교체.
+ * WIX NotificationIntentAdapter / PushNotificationProps → 표준 Intent/Bundle 방식으로 교체.
+ */
+public class NotificationReplyBroadcastReceiver extends BroadcastReceiver {
+    private static final String TAG = "NotifReplyReceiver";
+
+    private Context mContext;
+    private Bundle bundle;
+    private NotificationManager notificationManager;
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        try {
+            final CharSequence message = getReplyMessage(intent);
+            if (message == null) return;
+
+            mContext = context;
+            bundle = intent.getBundleExtra(CustomPushNotificationHelper.NOTIFICATION);
+            notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
+
+            final int notificationId = intent.getIntExtra(CustomPushNotificationHelper.NOTIFICATION_ID, -1);
+            final String serverUrl = bundle.getString("server_url");
+
+            if (serverUrl != null) {
+                replyToMessage(serverUrl, notificationId, message);
+            } else {
+                onReplyFailed(notificationId);
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "onReceive error: " + e.getMessage());
+            e.printStackTrace();
+        }
+    }
+
+    protected void replyToMessage(final String serverUrl, final int notificationId,
+                                   final CharSequence message) {
+        final String channelId = bundle.getString("channel_id");
+        final String postId = bundle.getString("post_id");
+        String rootId = bundle.getString("root_id");
+        if (android.text.TextUtils.isEmpty(rootId)) rootId = postId;
+
+        try {
+            JSONObject body = new JSONObject();
+            body.put("channel_id", channelId);
+            body.put("message", message.toString());
+            body.put("root_id", rootId);
+
+            final String finalRootId = rootId;
+            Network.INSTANCE.post(serverUrl, "/api/v4/posts?set_online=false", body,
+                    null,
+                    json -> {
+                        if (json != null) {
+                            try {
+                                if (json.has("status_code")) {
+                                    int statusCode = json.getInt("status_code");
+                                    if (statusCode < 200 || statusCode >= 300) {
+                                        Log.i(TAG, "Reply FAILED status=" + statusCode);
+                                        onReplyFailed(notificationId);
+                                        return null;
+                                    }
+                                }
+                                onReplySuccess(notificationId, message);
+                                Log.i(TAG, "Reply SUCCESS");
+                            } catch (JSONException e) {
+                                e.printStackTrace();
+                                onReplyFailed(notificationId);
+                            }
+                        } else {
+                            Log.i(TAG, "Reply FAILED: null response");
+                            onReplyFailed(notificationId);
+                        }
+                        return null;
+                    },
+                    e -> {
+                        Log.i(TAG, "Reply FAILED exception: " + e.getMessage());
+                        onReplyFailed(notificationId);
+                        return null;
+                    }
+            );
+        } catch (JSONException e) {
+            Log.e(TAG, "JSON error: " + e.getMessage());
+            onReplyFailed(notificationId);
+        }
+    }
+
+    protected void onReplyFailed(int notificationId) {
+        recreateNotification(notificationId, "Message failed to send.");
+    }
+
+    protected void onReplySuccess(int notificationId, final CharSequence message) {
+        recreateNotification(notificationId, message);
+    }
+
+    private void recreateNotification(int notificationId, final CharSequence message) {
+        // 표준 PendingIntent 생성 (WIX NotificationIntentAdapter 제거)
+        Intent openIntent = new Intent(mContext, MainActivity.class);
+        openIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        openIntent.putExtras(bundle);
+
+        PendingIntent pendingIntent = PendingIntent.getActivity(
+                mContext, notificationId, openIntent,
+                PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE);
+
+        NotificationCompat.Builder builder =
+                CustomPushNotificationHelper.createNotificationBuilder(mContext, pendingIntent, bundle, false);
+
+        Notification notification = builder.build();
+        NotificationCompat.MessagingStyle messagingStyle =
+                NotificationCompat.MessagingStyle.extractMessagingStyleFromNotification(notification);
+
+        if (messagingStyle != null) {
+            messagingStyle.addMessage(message, System.currentTimeMillis(), (Person) null);
+            notification = builder.setStyle(messagingStyle).build();
+        }
+
+        notificationManager.notify(notificationId, notification);
+    }
+
+    private CharSequence getReplyMessage(Intent intent) {
+        Bundle remoteInput = RemoteInput.getResultsFromIntent(intent);
+        if (remoteInput != null) {
+            return remoteInput.getCharSequence(CustomPushNotificationHelper.KEY_TEXT_REPLY);
+        }
+        return null;
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/ReceiptDelivery.java
+++ b/android/app/src/main/java/com/tokilabs/mattermost/ReceiptDelivery.java
@ -0,0 +1,65 @@
+package com.tokilabs.mattermost;
+
+import android.os.Bundle;
+import android.util.Log;
+
+import com.tokilabs.mattermost.helpers.Network;
+
+import org.json.JSONObject;
+
+import java.util.Objects;
+
+import okhttp3.Response;
+
+/**
+ * 알림 수신 확인(ACK) 서버 전송.
+ * mattermost-mobile의 ReceiptDelivery.java 이식 버전.
+ * com.facebook.react.bridge.Arguments / WritableMap → org.json.JSONObject / android.os.Bundle 교체.
+ */
+public class ReceiptDelivery {
+    private static final String TAG = "ReceiptDelivery";
+    private static final String[] ACK_KEYS = {
+        "post_id", "root_id", "category", "message", "team_id",
+        "channel_id", "channel_name", "type", "sender_id", "sender_name", "version"
+    };
+
+    public static Bundle send(final String ackId, final String serverUrl,
+                               final String postId, final String type, final boolean isIdLoaded) {
+        Log.i(TAG, String.format("Send ACK=%s TYPE=%s to URL=%s ID-LOADED=%s", ackId, type, serverUrl, isIdLoaded));
+
+        try {
+            JSONObject body = new JSONObject();
+            body.put("id", ackId);
+            body.put("received_at", System.currentTimeMillis());
+            body.put("platform", "android");
+            body.put("type", type);
+            body.put("post_id", postId);
+            body.put("is_id_loaded", isIdLoaded);
+
+            try (Response response = Network.INSTANCE.postSync(serverUrl, "api/v4/notifications/ack", body)) {
+                String responseBody = Objects.requireNonNull(response.body()).string();
+                JSONObject jsonResponse = new JSONObject(responseBody);
+                return parseAckResponse(jsonResponse);
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "Send receipt delivery failed: " + e.getMessage());
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    public static Bundle parseAckResponse(JSONObject jsonResponse) {
+        try {
+            Bundle bundle = new Bundle();
+            for (String key : ACK_KEYS) {
+                if (jsonResponse.has(key)) {
+                    bundle.putString(key, jsonResponse.getString(key));
+                }
+            }
+            return bundle;
+        } catch (Exception e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/helpers/BitmapCache.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/helpers/BitmapCache.kt
@ -0,0 +1,28 @@
+package com.tokilabs.mattermost.helpers
+
+import android.graphics.Bitmap
+import android.util.LruCache
+
+/**
+ * 사용자 아바타 비트맵 캐시.
+ * mattermost-mobile의 BitmapCache 이식.
+ */
+class BitmapCache {
+    private data class CacheKey(val userId: String, val serverUrl: String)
+    private data class CacheEntry(val bitmap: Bitmap, val lastUpdateAt: Double)
+
+    private val cache = LruCache<CacheKey, CacheEntry>(20)
+
+    fun bitmap(userId: String, lastUpdateAt: Double, serverUrl: String): Bitmap? {
+        val entry = cache.get(CacheKey(userId, serverUrl)) ?: return null
+        return if (entry.lastUpdateAt == lastUpdateAt) entry.bitmap else null
+    }
+
+    fun insertBitmap(bitmap: Bitmap, userId: String, lastUpdateAt: Double, serverUrl: String) {
+        cache.put(CacheKey(userId, serverUrl), CacheEntry(bitmap, lastUpdateAt))
+    }
+
+    fun removeBitmap(userId: String, serverUrl: String) {
+        cache.remove(CacheKey(userId, serverUrl))
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/helpers/CustomPushNotificationHelper.java
+++ b/android/app/src/main/java/com/tokilabs/mattermost/helpers/CustomPushNotificationHelper.java
@ -0,0 +1,525 @@
+package com.tokilabs.mattermost.helpers;
+
+import android.annotation.SuppressLint;
+import android.app.Notification;
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.Intent;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.PorterDuff;
+import android.graphics.PorterDuffXfermode;
+import android.graphics.Rect;
+import android.graphics.RectF;
+import android.os.Build;
+import android.os.Bundle;
+import android.text.TextUtils;
+import android.util.Base64;
+import android.util.Log;
+
+import androidx.annotation.NonNull;
+import androidx.core.app.NotificationCompat;
+import androidx.core.app.NotificationManagerCompat;
+import androidx.core.app.Person;
+import androidx.core.app.RemoteInput;
+import androidx.core.graphics.drawable.IconCompat;
+
+import com.tokilabs.mattermost.NotificationDismissService;
+import com.tokilabs.mattermost.NotificationReplyBroadcastReceiver;
+import com.tokilabs.mattermost.R;
+import com.tokilabs.mattermost.helpers.db.MattermostDatabase;
+
+import java.io.IOException;
+import java.security.KeyFactory;
+import java.security.PublicKey;
+import java.security.spec.X509EncodedKeySpec;
+import java.util.Date;
+import java.util.Objects;
+
+import io.jsonwebtoken.IncorrectClaimException;
+import io.jsonwebtoken.JwtException;
+import io.jsonwebtoken.Jwts;
+import io.jsonwebtoken.MissingClaimException;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.Response;
+
+/**
+ * 알림 UI 생성 및 JWT 서명 검증.
+ * mattermost-mobile의 com.mattermost.helpers.CustomPushNotificationHelper 이식 버전.
+ * com.facebook.react.bridge.* → android.os.Bundle / 표준 Java 타입으로 교체.
+ * WatermelonDB → DatabaseHelper (Room 기반)로 교체.
+ */
+public class CustomPushNotificationHelper {
+    public static final String CHANNEL_HIGH_IMPORTANCE_ID = "channel_01";
+    public static final String CHANNEL_MIN_IMPORTANCE_ID = "channel_02";
+    public static final String KEY_TEXT_REPLY = "CAN_REPLY";
+    public static final String NOTIFICATION_ID = "notificationId";
+    public static final String NOTIFICATION = "notification";
+    public static final String PUSH_TYPE_MESSAGE = "message";
+    public static final String PUSH_TYPE_CLEAR = "clear";
+    public static final String PUSH_TYPE_SESSION = "session";
+    public static final String CATEGORY_CAN_REPLY = "CAN_REPLY";
+
+    private static final String TAG = "PushNotifHelper";
+
+    private static NotificationChannel mHighImportanceChannel;
+    private static NotificationChannel mMinImportanceChannel;
+
+    private static final OkHttpClient client = new OkHttpClient();
+    private static final BitmapCache bitmapCache = new BitmapCache();
+
+    // ─────────────────────────────────────────────────────────────────────
+    // Public API
+    // ─────────────────────────────────────────────────────────────────────
+
+    public static NotificationCompat.Builder createNotificationBuilder(
+            Context context, PendingIntent intent, Bundle bundle, boolean createSummary) {
+
+        final NotificationCompat.Builder notification =
+                new NotificationCompat.Builder(context, CHANNEL_HIGH_IMPORTANCE_ID);
+
+        String postId = bundle.getString("post_id");
+        String rootId = bundle.getString("root_id");
+        String channelId = bundle.getString("channel_id");
+        int notificationId = postId != null ? postId.hashCode() : NotificationHelper.MESSAGE_NOTIFICATION_ID;
+
+        boolean isCrtEnabled = bundle.containsKey("is_crt_enabled") &&
+                Objects.equals(bundle.getString("is_crt_enabled"), "true");
+        String groupId = isCrtEnabled && !TextUtils.isEmpty(rootId) ? rootId : channelId;
+
+        addNotificationExtras(notification, bundle);
+        setNotificationIcons(context, notification, bundle);
+        setNotificationMessagingStyle(context, notification, bundle);
+        setNotificationGroup(notification, groupId, createSummary);
+        setNotificationBadgeType(notification);
+        setNotificationChannel(context, notification);
+        setNotificationDeleteIntent(context, notification, bundle, notificationId);
+        addNotificationReplyAction(context, notification, bundle, notificationId);
+
+        notification
+                .setContentIntent(intent)
+                .setVisibility(NotificationCompat.VISIBILITY_PRIVATE)
+                .setPriority(Notification.PRIORITY_HIGH)
+                .setCategory(Notification.CATEGORY_MESSAGE)
+                .setAutoCancel(true);
+
+        return notification;
+    }
+
+    public static void createNotificationChannels(Context context) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return;
+
+        final NotificationManagerCompat notificationManager = NotificationManagerCompat.from(context);
+
+        if (mHighImportanceChannel == null) {
+            mHighImportanceChannel = new NotificationChannel(
+                    CHANNEL_HIGH_IMPORTANCE_ID, "High Importance", NotificationManager.IMPORTANCE_HIGH);
+            mHighImportanceChannel.setShowBadge(true);
+            notificationManager.createNotificationChannel(mHighImportanceChannel);
+        }
+
+        if (mMinImportanceChannel == null) {
+            mMinImportanceChannel = new NotificationChannel(
+                    CHANNEL_MIN_IMPORTANCE_ID, "Min Importance", NotificationManager.IMPORTANCE_MIN);
+            mMinImportanceChannel.setShowBadge(true);
+            notificationManager.createNotificationChannel(mMinImportanceChannel);
+        }
+    }
+
+    /**
+     * JWT 서명 검증.
+     * 원본 로직 그대로 유지 (DatabaseHelper만 Room 기반으로 교체).
+     */
+    public static boolean verifySignature(final Context context, String signature,
+                                          String serverUrl, String ackId) {
+        if (signature == null) {
+            Log.i(TAG, "No signature in the notification (backward compat)");
+            return true;
+        }
+
+        if (serverUrl == null) {
+            Log.i(TAG, "No server_url for server_id");
+            return false;
+        }
+
+        DatabaseHelper dbHelper = DatabaseHelper.getInstance();
+        if (dbHelper == null) {
+            Log.i(TAG, "Cannot access the database");
+            return false;
+        }
+
+        MattermostDatabase db = dbHelper.getDatabaseForServer(context, serverUrl);
+        if (db == null) {
+            Log.i(TAG, "Cannot access the server database");
+            return false;
+        }
+
+        if ("NO_SIGNATURE".equals(signature)) {
+            String version = db.queryConfigServerVersion();
+            if (version == null) {
+                Log.i(TAG, "No server version");
+                return false;
+            }
+            if (!version.matches("[0-9]+(\\.[0-9]+)*")) {
+                Log.i(TAG, "Invalid server version");
+                return false;
+            }
+
+            String[] parts = version.split("\\.");
+            int major = parts.length > 0 ? Integer.parseInt(parts[0]) : 0;
+            int minor = parts.length > 1 ? Integer.parseInt(parts[1]) : 0;
+            int patch = parts.length > 2 ? Integer.parseInt(parts[2]) : 0;
+
+            int[][] targets = {{9,8,0},{9,7,3},{9,6,3},{9,5,5},{8,1,14}};
+            boolean rejected = false;
+            for (int i = 0; i < targets.length; i++) {
+                boolean first = i == 0;
+                int majorTarget = targets[i][0];
+                int minorTarget = targets[i][1];
+                int patchTarget = targets[i][2];
+
+                if (major > majorTarget) { rejected = first; break; }
+                if (major < majorTarget) { continue; }
+                if (minor > minorTarget) { rejected = first; break; }
+                if (minor < minorTarget) { continue; }
+                if (patch >= patchTarget) { rejected = true; break; }
+                return true;
+            }
+
+            if (rejected) {
+                Log.i(TAG, "Server version should send signature");
+                return false;
+            }
+            return true;
+        }
+
+        String signingKey = db.queryConfigSigningKey();
+        if (signingKey == null) {
+            Log.i(TAG, "No signing key");
+            return false;
+        }
+
+        try {
+            byte[] encoded = Base64.decode(signingKey, 0);
+            KeyFactory kf = KeyFactory.getInstance("EC");
+            PublicKey pubKey = kf.generatePublic(new X509EncodedKeySpec(encoded));
+
+            String storedDeviceToken = dbHelper.getDeviceToken();
+            if (storedDeviceToken == null) {
+                Log.i(TAG, "No device token stored");
+                return false;
+            }
+            String[] tokenParts = storedDeviceToken.split(":", 2);
+            if (tokenParts.length != 2) {
+                Log.i(TAG, "Wrong stored device token format");
+                return false;
+            }
+            String deviceToken = tokenParts[1].substring(0, tokenParts[1].length() - 1);
+            if (deviceToken.isEmpty()) {
+                Log.i(TAG, "Empty stored device token");
+                return false;
+            }
+
+            Jwts.parser()
+                    .require("ack_id", ackId)
+                    .require("device_id", deviceToken)
+                    .verifyWith((PublicKey) pubKey)
+                    .build()
+                    .parseSignedClaims(signature);
+
+        } catch (MissingClaimException e) {
+            Log.i(TAG, "Missing claim: " + e.getMessage());
+            return false;
+        } catch (IncorrectClaimException e) {
+            Log.i(TAG, "Incorrect claim: " + e.getMessage());
+            return false;
+        } catch (JwtException e) {
+            Log.i(TAG, "Cannot verify JWT: " + e.getMessage());
+            return false;
+        } catch (Exception e) {
+            Log.i(TAG, "Exception while parsing JWT: " + e.getMessage());
+            return false;
+        }
+
+        return true;
+    }
+
+    // ─────────────────────────────────────────────────────────────────────
+    // Private helpers (원본 로직 그대로)
+    // ─────────────────────────────────────────────────────────────────────
+
+    private static void addNotificationExtras(NotificationCompat.Builder notification, Bundle bundle) {
+        Bundle userInfoBundle = bundle.getBundle("userInfo");
+        if (userInfoBundle == null) userInfoBundle = new Bundle();
+
+        putIfNotNull(userInfoBundle, "channel_id", bundle.getString("channel_id"));
+        putIfNotNull(userInfoBundle, "post_id", bundle.getString("post_id"));
+        putIfNotNull(userInfoBundle, "root_id", bundle.getString("root_id"));
+        putIfNotNull(userInfoBundle, "is_crt_enabled", bundle.getString("is_crt_enabled"));
+        putIfNotNull(userInfoBundle, "server_url", bundle.getString("server_url"));
+
+        notification.addExtras(userInfoBundle);
+    }
+
+    @SuppressLint("UnspecifiedImmutableFlag")
+    private static void addNotificationReplyAction(Context context, NotificationCompat.Builder notification,
+                                                    Bundle bundle, int notificationId) {
+        String postId = bundle.getString("post_id");
+        String serverUrl = bundle.getString("server_url");
+        boolean canReply = bundle.containsKey("category") &&
+                Objects.equals(bundle.getString("category"), CATEGORY_CAN_REPLY);
+
+        if (TextUtils.isEmpty(postId) || serverUrl == null || !canReply) return;
+
+        Intent replyIntent = new Intent(context, NotificationReplyBroadcastReceiver.class);
+        replyIntent.setAction(KEY_TEXT_REPLY);
+        replyIntent.putExtra(NOTIFICATION_ID, notificationId);
+        replyIntent.putExtra(NOTIFICATION, bundle);
+
+        PendingIntent replyPendingIntent;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            replyPendingIntent = PendingIntent.getBroadcast(context, notificationId, replyIntent,
+                    PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_MUTABLE);
+        } else {
+            replyPendingIntent = PendingIntent.getBroadcast(context, notificationId, replyIntent,
+                    PendingIntent.FLAG_UPDATE_CURRENT);
+        }
+
+        RemoteInput remoteInput = new RemoteInput.Builder(KEY_TEXT_REPLY).setLabel("Reply").build();
+
+        NotificationCompat.Action replyAction = new NotificationCompat.Action.Builder(
+                R.drawable.ic_notif_action_reply, "Reply", replyPendingIntent)
+                .addRemoteInput(remoteInput)
+                .setAllowGeneratedReplies(true)
+                .build();
+
+        notification.setShowWhen(true).addAction(replyAction);
+    }
+
+    private static void setNotificationMessagingStyle(Context context,
+                                                       NotificationCompat.Builder notification, Bundle bundle) {
+        notification.setStyle(getMessagingStyle(context, bundle));
+    }
+
+    private static NotificationCompat.MessagingStyle getMessagingStyle(Context context, Bundle bundle) {
+        final String serverUrl = bundle.getString("server_url");
+        final String type = bundle.getString("type");
+        String urlOverride = bundle.getString("override_icon_url");
+
+        Person.Builder sender = new Person.Builder().setKey("me").setName("Me");
+
+        if (serverUrl != null && type != null && !type.equals(PUSH_TYPE_SESSION)) {
+            try {
+                Bitmap avatar = userAvatar(context, serverUrl, "me", urlOverride);
+                if (avatar != null) sender.setIcon(IconCompat.createWithBitmap(avatar));
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+
+        NotificationCompat.MessagingStyle messagingStyle = new NotificationCompat.MessagingStyle(sender.build());
+        String conversationTitle = getConversationTitle(bundle);
+        setMessagingStyleConversationTitle(messagingStyle, conversationTitle, bundle);
+        addMessagingStyleMessages(context, messagingStyle, conversationTitle, bundle);
+
+        return messagingStyle;
+    }
+
+    private static void addMessagingStyleMessages(Context context,
+                                                   NotificationCompat.MessagingStyle messagingStyle,
+                                                   String conversationTitle, Bundle bundle) {
+        String message = bundle.getString("message", bundle.getString("body"));
+        String senderId = bundle.getString("sender_id");
+        final String serverUrl = bundle.getString("server_url");
+        final String type = bundle.getString("type");
+        String urlOverride = bundle.getString("override_icon_url");
+
+        if (senderId == null) senderId = "sender_id";
+        String senderName = getSenderName(bundle);
+
+        if (conversationTitle == null || !TextUtils.isEmpty(senderName.trim())) {
+            message = removeSenderNameFromMessage(message, senderName);
+        }
+
+        long timestamp = new Date().getTime();
+        Person.Builder sender = new Person.Builder().setKey(senderId).setName(senderName);
+
+        if (serverUrl != null && type != null && !type.equals(PUSH_TYPE_SESSION)) {
+            try {
+                Bitmap avatar = userAvatar(context, serverUrl, senderId, urlOverride);
+                if (avatar != null) sender.setIcon(IconCompat.createWithBitmap(avatar));
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+
+        messagingStyle.addMessage(message, timestamp, sender.build());
+    }
+
+    private static void setNotificationIcons(Context context, NotificationCompat.Builder notification, Bundle bundle) {
+        String channelName = getConversationTitle(bundle);
+        String senderName = bundle.getString("sender_name");
+        String serverUrl = bundle.getString("server_url");
+        String urlOverride = bundle.getString("override_icon_url");
+
+        notification.setSmallIcon(R.mipmap.ic_notification);
+
+        if (serverUrl != null && channelName.equals(senderName)) {
+            try {
+                String senderId = bundle.getString("sender_id");
+                Bitmap avatar = userAvatar(context, serverUrl, senderId, urlOverride);
+                if (avatar != null) notification.setLargeIcon(avatar);
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    private static void setNotificationGroup(NotificationCompat.Builder notification,
+                                              String channelId, boolean setAsSummary) {
+        notification.setGroup(channelId);
+        if (setAsSummary) notification.setGroupSummary(true);
+    }
+
+    private static void setNotificationBadgeType(NotificationCompat.Builder notification) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            notification.setBadgeIconType(NotificationCompat.BADGE_ICON_LARGE);
+        }
+    }
+
+    private static void setNotificationChannel(Context context, NotificationCompat.Builder notification) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return;
+        if (mHighImportanceChannel == null) createNotificationChannels(context);
+        notification.setChannelId(mHighImportanceChannel.getId());
+    }
+
+    @SuppressLint("UnspecifiedImmutableFlag")
+    private static void setNotificationDeleteIntent(Context context, NotificationCompat.Builder notification,
+                                                     Bundle bundle, int notificationId) {
+        final String PUSH_NOTIFICATION_EXTRA_NAME = "pushNotification";
+        Intent delIntent = new Intent(context, NotificationDismissService.class);
+        delIntent.putExtra(NOTIFICATION_ID, notificationId);
+        delIntent.putExtra(PUSH_NOTIFICATION_EXTRA_NAME, bundle);
+        PendingIntent deleteIntent = PendingIntent.getService(context,
+                (int) System.currentTimeMillis(), delIntent,
+                PendingIntent.FLAG_ONE_SHOT | PendingIntent.FLAG_IMMUTABLE);
+        notification.setDeleteIntent(deleteIntent);
+    }
+
+    private static void setMessagingStyleConversationTitle(
+            NotificationCompat.MessagingStyle messagingStyle, String conversationTitle, Bundle bundle) {
+        String channelName = getConversationTitle(bundle);
+        String senderName = bundle.getString("sender_name");
+        if (TextUtils.isEmpty(senderName)) senderName = getSenderName(bundle);
+
+        if (conversationTitle != null && !channelName.equals(senderName)) {
+            messagingStyle.setConversationTitle(conversationTitle);
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+                messagingStyle.setGroupConversation(true);
+            }
+        }
+    }
+
+    private static String getConversationTitle(Bundle bundle) {
+        String title = bundle.getString("channel_name");
+        if (TextUtils.isEmpty(title)) title = bundle.getString("sender_name");
+        if (TextUtils.isEmpty(title)) title = bundle.getString("title", "");
+        return title;
+    }
+
+    private static String getSenderName(Bundle bundle) {
+        String senderName = bundle.getString("sender_name");
+        if (senderName != null) return senderName;
+
+        String channelName = bundle.getString("channel_name");
+        if (channelName != null && channelName.startsWith("@")) return channelName;
+
+        String message = bundle.getString("message");
+        if (message != null) {
+            String name = message.split(":")[0];
+            if (!name.equals(message)) return name;
+        }
+
+        return getConversationTitle(bundle);
+    }
+
+    private static String removeSenderNameFromMessage(String message, String senderName) {
+        int index = message.indexOf(senderName);
+        if (index == 0) message = message.substring(senderName.length());
+        return message.replaceFirst(": ", "").trim();
+    }
+
+    private static Bitmap getCircleBitmap(Bitmap bitmap) {
+        final Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
+        final Canvas canvas = new Canvas(output);
+        final Paint paint = new Paint();
+        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
+        final RectF rectF = new RectF(rect);
+
+        paint.setAntiAlias(true);
+        canvas.drawARGB(0, 0, 0, 0);
+        paint.setColor(Color.RED);
+        canvas.drawOval(rectF, paint);
+        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
+        canvas.drawBitmap(bitmap, rect, rect, paint);
+        bitmap.recycle();
+
+        return output;
+    }
+
+    private static Bitmap userAvatar(final Context context, @NonNull final String serverUrl,
+                                      final String userId, final String urlOverride) throws IOException {
+        try {
+            Response response;
+            Double lastUpdateAt = 0.0;
+
+            if (!TextUtils.isEmpty(urlOverride)) {
+                Request request = new Request.Builder().url(urlOverride).build();
+                response = client.newCall(request).execute();
+            } else {
+                DatabaseHelper dbHelper = DatabaseHelper.getInstance();
+                if (dbHelper != null) {
+                    MattermostDatabase db = dbHelper.getDatabaseForServer(context, serverUrl);
+                    if (db != null) {
+                        lastUpdateAt = db.getLastPictureUpdate(userId);
+                        if (lastUpdateAt == null) lastUpdateAt = 0.0;
+                        db.close();
+                    }
+                }
+
+                Bitmap cached = bitmapCache.bitmap(userId, lastUpdateAt, serverUrl);
+                if (cached != null) {
+                    return getCircleBitmap(cached.copy(cached.getConfig(), false));
+                }
+
+                bitmapCache.removeBitmap(userId, serverUrl);
+                String url = serverUrl.trimEnd('/') + "/api/v4/users/" + userId + "/image";
+                response = Network.INSTANCE.getSync(serverUrl, "api/v4/users/" + userId + "/image", null);
+            }
+
+            if (response.code() == 200 && response.body() != null) {
+                byte[] bytes = response.body().bytes();
+                Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
+                if (TextUtils.isEmpty(urlOverride) && !TextUtils.isEmpty(userId)) {
+                    bitmapCache.insertBitmap(bitmap.copy(bitmap.getConfig(), false), userId, lastUpdateAt, serverUrl);
+                }
+                return getCircleBitmap(bitmap);
+            }
+
+            return null;
+        } catch (Exception e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    private static void putIfNotNull(Bundle bundle, String key, String value) {
+        if (value != null) bundle.putString(key, value);
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/helpers/DatabaseHelper.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/helpers/DatabaseHelper.kt
@ -0,0 +1,102 @@
+package com.tokilabs.mattermost.helpers
+
+import android.content.Context
+import android.util.Log
+import com.tokilabs.mattermost.helpers.db.GlobalDatabase
+import com.tokilabs.mattermost.helpers.db.GlobalEntity
+import com.tokilabs.mattermost.helpers.db.MattermostDatabase
+import com.tokilabs.mattermost.helpers.db.ServerEntity
+
+/**
+ * 서버별 DB 접근 및 디바이스 토큰 관리.
+ * mattermost-mobile의 DatabaseHelper (WatermelonDB 기반) → Room DB 기반으로 교체.
+ *
+ * Global DB: Servers 목록, deviceToken
+ * Server DB: Config(버전/서명키), User(아바타), System(currentUserId)
+ */
+class DatabaseHelper private constructor(private val context: Context) {
+
+    companion object {
+        private const val TAG = "DatabaseHelper"
+        private const val DEVICE_TOKEN_KEY = "deviceToken"
+
+        @Volatile
+        private var instance: DatabaseHelper? = null
+
+        fun getInstance(): DatabaseHelper? = instance
+
+        fun init(context: Context): DatabaseHelper {
+            return instance ?: synchronized(this) {
+                instance ?: DatabaseHelper(context.applicationContext).also { instance = it }
+            }
+        }
+    }
+
+    private val globalDb by lazy { GlobalDatabase.getInstance(context) }
+
+    // ─── 디바이스 토큰 ────────────────────────────────────────────────────────
+
+    fun getDeviceToken(): String? {
+        return try {
+            globalDb.globalDao().getValue(DEVICE_TOKEN_KEY)
+        } catch (e: Exception) {
+            Log.e(TAG, "getDeviceToken error: ${e.message}")
+            null
+        }
+    }
+
+    fun saveDeviceToken(token: String) {
+        try {
+            globalDb.globalDao().upsert(GlobalEntity(DEVICE_TOKEN_KEY, token))
+            Log.i(TAG, "Device token saved")
+        } catch (e: Exception) {
+            Log.e(TAG, "saveDeviceToken error: ${e.message}")
+        }
+    }
+
+    // ─── 서버 목록 ────────────────────────────────────────────────────────────
+
+    /** 단일 서버 URL 반환 (서버가 하나만 있는 경우) */
+    val onlyServerUrl: String?
+        get() = try {
+            val servers = globalDb.serversDao().getAll()
+            if (servers.size == 1) servers.first().url else null
+        } catch (e: Exception) {
+            null
+        }
+
+    /** server_id(identifier)로 서버 URL 조회 */
+    fun getServerUrlForIdentifier(serverId: String): String? {
+        return try {
+            globalDb.serversDao().getAll()
+                .firstOrNull { it.identifier == serverId }?.url
+        } catch (e: Exception) {
+            null
+        }
+    }
+
+    fun saveServerUrl(serverUrl: String, identifier: String? = null) {
+        try {
+            globalDb.serversDao().upsert(
+                ServerEntity(url = serverUrl, dbPath = "", identifier = identifier)
+            )
+        } catch (e: Exception) {
+            Log.e(TAG, "saveServerUrl error: ${e.message}")
+        }
+    }
+
+    // ─── 서버별 DB ────────────────────────────────────────────────────────────
+
+    /**
+     * 서버 URL에 해당하는 Room DB 반환.
+     * JWT 검증(CustomPushNotificationHelper), 데이터 페칭(PushNotificationDataHelper)에서 사용.
+     */
+    fun getDatabaseForServer(context: Context, serverUrl: String): MattermostDatabase? {
+        return try {
+            MattermostDatabase.getInstance(context, serverUrl)
+        } catch (e: Exception) {
+            Log.e(TAG, "getDatabaseForServer error for $serverUrl: ${e.message}")
+            null
+        }
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/helpers/Network.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/helpers/Network.kt
@ -0,0 +1,116 @@
+package com.tokilabs.mattermost.helpers
+
+import android.util.Log
+import okhttp3.MediaType.Companion.toMediaType
+import okhttp3.OkHttpClient
+import okhttp3.Request
+import okhttp3.RequestBody.Companion.toRequestBody
+import okhttp3.Response
+import org.json.JSONObject
+import java.util.concurrent.TimeUnit
+
+/**
+ * OkHttp 기반 HTTP 클라이언트.
+ * mattermost-mobile의 com.mattermost.helpers.Network 대체.
+ */
+object Network {
+    private val client = OkHttpClient.Builder()
+        .connectTimeout(30, TimeUnit.SECONDS)
+        .readTimeout(30, TimeUnit.SECONDS)
+        .writeTimeout(30, TimeUnit.SECONDS)
+        .build()
+
+    private val JSON_MEDIA_TYPE = "application/json; charset=utf-8".toMediaType()
+    private const val TAG = "NomadNetwork"
+
+    /**
+     * 인증 토큰 저장소 (DatabaseHelper에서 읽어 설정)
+     * key: serverUrl, value: token
+     */
+    private val tokenCache = mutableMapOf<String, String>()
+
+    fun setToken(serverUrl: String, token: String) {
+        tokenCache[serverUrl] = token
+    }
+
+    fun clearToken(serverUrl: String) {
+        tokenCache.remove(serverUrl)
+    }
+
+    /**
+     * 동기 POST 요청 (코루틴 내부에서 사용)
+     */
+    fun postSync(serverUrl: String, endpoint: String, body: JSONObject, headers: Map<String, String> = emptyMap()): Response {
+        val url = buildUrl(serverUrl, endpoint)
+        val requestBody = body.toString().toRequestBody(JSON_MEDIA_TYPE)
+        val requestBuilder = Request.Builder()
+            .url(url)
+            .post(requestBody)
+            .addHeader("Content-Type", "application/json")
+
+        tokenCache[serverUrl]?.let { requestBuilder.addHeader("Authorization", "Bearer $it") }
+        headers.forEach { (k, v) -> requestBuilder.addHeader(k, v) }
+
+        Log.i(TAG, "POST $url")
+        return client.newCall(requestBuilder.build()).execute()
+    }
+
+    /**
+     * 비동기 POST 요청 (BroadcastReceiver 등에서 사용)
+     */
+    fun post(serverUrl: String, endpoint: String, body: JSONObject,
+             headers: Map<String, String> = emptyMap(),
+             onSuccess: (JSONObject?) -> Unit,
+             onFailure: (Exception) -> Unit) {
+        val url = buildUrl(serverUrl, endpoint)
+        val requestBody = body.toString().toRequestBody(JSON_MEDIA_TYPE)
+        val requestBuilder = Request.Builder()
+            .url(url)
+            .post(requestBody)
+            .addHeader("Content-Type", "application/json")
+
+        tokenCache[serverUrl]?.let { requestBuilder.addHeader("Authorization", "Bearer $it") }
+        headers.forEach { (k, v) -> requestBuilder.addHeader(k, v) }
+
+        Log.i(TAG, "POST async $url")
+        client.newCall(requestBuilder.build()).enqueue(object : okhttp3.Callback {
+            override fun onFailure(call: okhttp3.Call, e: java.io.IOException) {
+                Log.e(TAG, "POST failed: ${e.message}")
+                onFailure(e)
+            }
+
+            override fun onResponse(call: okhttp3.Call, response: Response) {
+                try {
+                    val responseBody = response.body?.string()
+                    val json = if (!responseBody.isNullOrEmpty()) JSONObject(responseBody) else null
+                    onSuccess(json)
+                } catch (e: Exception) {
+                    Log.e(TAG, "POST response parse error: ${e.message}")
+                    onSuccess(null)
+                }
+            }
+        })
+    }
+
+    /**
+     * 동기 GET 요청
+     */
+    fun getSync(serverUrl: String, endpoint: String, headers: Map<String, String>? = null): Response {
+        val url = buildUrl(serverUrl, endpoint)
+        val requestBuilder = Request.Builder()
+            .url(url)
+            .get()
+
+        tokenCache[serverUrl]?.let { requestBuilder.addHeader("Authorization", "Bearer $it") }
+        headers?.forEach { (k, v) -> requestBuilder.addHeader(k, v) }
+
+        Log.i(TAG, "GET $url")
+        return client.newCall(requestBuilder.build()).execute()
+    }
+
+    private fun buildUrl(serverUrl: String, endpoint: String): String {
+        val base = serverUrl.trimEnd('/')
+        val path = endpoint.trimStart('/')
+        return "$base/$path"
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/helpers/NotificationHelper.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/helpers/NotificationHelper.kt
@ -0,0 +1,93 @@
+package com.tokilabs.mattermost.helpers
+
+import android.app.NotificationManager
+import android.content.Context
+import android.os.Bundle
+import android.util.Log
+import androidx.core.app.NotificationManagerCompat
+
+/**
+ * 알림 유틸리티.
+ * mattermost-mobile의 com.mattermost.rnutils.helpers.NotificationHelper 대응.
+ */
+object NotificationHelper {
+    private const val TAG = "NotificationHelper"
+    const val MESSAGE_NOTIFICATION_ID = -1
+
+    // 알림 ID → Bundle 저장소 (요약 알림 처리용)
+    private val notificationPreferences = mutableMapOf<Int, Bundle>()
+
+    fun getNotificationId(bundle: Bundle): Int {
+        val postId = bundle.getString("post_id")
+        return postId?.hashCode() ?: MESSAGE_NOTIFICATION_ID
+    }
+
+    /**
+     * 알림을 preferences에 추가.
+     * @return true if this is the first notification for the group (→ createSummary)
+     */
+    fun addNotificationToPreferences(context: Context, notificationId: Int, bundle: Bundle): Boolean {
+        val channelId = bundle.getString("channel_id") ?: return true
+        val rootId = bundle.getString("root_id")
+        val isCRTEnabled = bundle.getString("is_crt_enabled") == "true"
+        val groupId = if (isCRTEnabled && !rootId.isNullOrEmpty()) rootId else channelId
+
+        val isFirst = notificationPreferences.none { (_, b) ->
+            val bGroupId = if (isCRTEnabled && !b.getString("root_id").isNullOrEmpty())
+                b.getString("root_id") else b.getString("channel_id")
+            bGroupId == groupId
+        }
+
+        notificationPreferences[notificationId] = bundle
+        return isFirst
+    }
+
+    /**
+     * 채널/스레드 알림 전체 초기화.
+     */
+    fun clearChannelOrThreadNotifications(context: Context, bundle: Bundle) {
+        val channelId = bundle.getString("channel_id") ?: return
+        val rootId = bundle.getString("root_id")
+        val isCRTEnabled = bundle.getString("is_crt_enabled") == "true"
+        val targetGroupId = if (isCRTEnabled && !rootId.isNullOrEmpty()) rootId else channelId
+
+        val notificationManager = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+        val toRemove = mutableListOf<Int>()
+
+        notificationPreferences.forEach { (id, b) ->
+            val bRootId = b.getString("root_id")
+            val bChannelId = b.getString("channel_id")
+            val bGroupId = if (isCRTEnabled && !bRootId.isNullOrEmpty()) bRootId else bChannelId
+            if (bGroupId == targetGroupId) {
+                notificationManager.cancel(id)
+                toRemove.add(id)
+                Log.i(TAG, "Cancelled notification id=$id for group=$targetGroupId")
+            }
+        }
+
+        toRemove.forEach { notificationPreferences.remove(it) }
+    }
+
+    /**
+     * 단일 알림 해제.
+     */
+    fun dismissNotification(context: Context, bundle: Bundle) {
+        val notificationId = getNotificationId(bundle)
+        val notificationManager = NotificationManagerCompat.from(context)
+        notificationManager.cancel(notificationId)
+        notificationPreferences.remove(notificationId)
+        Log.i(TAG, "Dismissed notification id=$notificationId")
+    }
+
+    /**
+     * 알림 표시.
+     */
+    fun postNotification(context: Context, notification: android.app.Notification, notificationId: Int) {
+        try {
+            val notificationManager = NotificationManagerCompat.from(context)
+            notificationManager.notify(notificationId, notification)
+        } catch (e: SecurityException) {
+            Log.e(TAG, "No notification permission: ${e.message}")
+        }
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/helpers/PushNotificationDataHelper.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/helpers/PushNotificationDataHelper.kt
@ -0,0 +1,145 @@
+package com.tokilabs.mattermost.helpers
+
+import android.content.Context
+import android.os.Bundle
+import android.util.Log
+import com.tokilabs.mattermost.helpers.db.MattermostDatabase
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+
+/**
+ * 알림 수신 시 필요한 데이터(채널/포스트/유저/스레드)를 DB에서 페칭.
+ * mattermost-mobile의 PushNotificationDataHelper.kt 이식 버전.
+ *
+ * 주요 변경:
+ * - com.facebook.react.bridge.* (Arguments, ReadableMap 등) → android.os.Bundle 사용
+ * - WatermelonDB (WMDatabase) → Room DB (MattermostDatabase)
+ * - 데이터 페칭 로직은 구조 유지, 실제 DB 쿼리는 MattermostDatabase.kt에서 구현
+ */
+class PushNotificationDataHelper(private val context: Context) {
+
+    suspend fun fetchAndStoreDataForPushNotification(initialData: Bundle, isFlutterInit: Boolean): Bundle? {
+        return withContext(Dispatchers.Default) {
+            PushNotificationDataRunnable.start(context, initialData, isFlutterInit)
+        }
+    }
+}
+
+object PushNotificationDataRunnable {
+    private const val TAG = "PushNotifDataHelper"
+    private val mutex = Mutex()
+
+    suspend fun start(context: Context, initialData: Bundle, isFlutterInit: Boolean): Bundle? {
+        mutex.withLock {
+            val serverUrl = initialData.getString("server_url") ?: return null
+            val dbHelper = DatabaseHelper.getInstance() ?: run {
+                Log.e(TAG, "DatabaseHelper not initialized")
+                return null
+            }
+            val db = dbHelper.getDatabaseForServer(context, serverUrl)
+
+            var result: Bundle? = null
+
+            try {
+                if (db != null) {
+                    val teamId = initialData.getString("team_id")
+                    val channelId = initialData.getString("channel_id")
+                    val postId = initialData.getString("post_id")
+                    val rootId = initialData.getString("root_id")
+                    val isCRTEnabled = initialData.getString("is_crt_enabled") == "true"
+                    val ackId = initialData.getString("ack_id")
+
+                    Log.i(TAG, "Start fetching notification data server=$serverUrl channel=$channelId ack=$ackId")
+
+                    val notificationData = Bundle()
+
+                    // 팀 정보 (TODO: Room DAO 구현 후 실제 쿼리로 교체)
+                    if (!teamId.isNullOrEmpty()) {
+                        fetchTeamIfNeeded(db, serverUrl, teamId)?.let {
+                            notificationData.putBundle("team", it)
+                        }
+                    }
+
+                    // 채널 / 포스트 정보
+                    if (channelId != null && postId != null) {
+                        fetchMyChannel(db, channelId)?.let { notificationData.putBundle("channel", it) }
+
+                        fetchPosts(db, serverUrl, channelId, isCRTEnabled, rootId)?.let {
+                            notificationData.putBundle("posts", it)
+                        }
+
+                        // 스레드 (CRT 활성화 시)
+                        if (isCRTEnabled && !rootId.isNullOrEmpty()) {
+                            fetchThread(db, serverUrl, rootId)?.let {
+                                notificationData.putBundle("thread", it)
+                            }
+                        }
+
+                        // 사용자 목록
+                        fetchNeededUsers(serverUrl, channelId)?.let {
+                            notificationData.putParcelableArray("users", it.toTypedArray())
+                        }
+                    }
+
+                    result = notificationData
+
+                    // Flutter가 초기화되지 않은 경우 DB에 저장 (다음 Flutter 부팅 시 로드)
+                    if (!isFlutterInit) {
+                        saveToDatabase(db, notificationData, teamId, channelId, isCRTEnabled)
+                    }
+
+                    Log.i(TAG, "Done processing push notification server=$serverUrl channel=$channelId ack=$ackId")
+                }
+            } catch (e: Exception) {
+                Log.e(TAG, "Error processing push notification: ${e.message}")
+                e.printStackTrace()
+            } finally {
+                db?.close()
+                Log.i(TAG, "DONE fetching notification data")
+            }
+
+            return result
+        }
+    }
+
+    // ─── 개별 데이터 페칭 (TODO: Room DAO 실제 쿼리로 교체) ──────────────
+
+    private fun fetchTeamIfNeeded(db: MattermostDatabase, serverUrl: String, teamId: String): Bundle? {
+        // TODO: db.teamDao().getTeam(teamId)
+        Log.i(TAG, "fetchTeamIfNeeded: teamId=$teamId (Room DAO 구현 필요)")
+        return null
+    }
+
+    private fun fetchMyChannel(db: MattermostDatabase, channelId: String): Bundle? {
+        // TODO: db.channelDao().getChannel(channelId)
+        Log.i(TAG, "fetchMyChannel: channelId=$channelId (Room DAO 구현 필요)")
+        return null
+    }
+
+    private fun fetchPosts(db: MattermostDatabase, serverUrl: String, channelId: String,
+                           isCRTEnabled: Boolean, rootId: String?): Bundle? {
+        // TODO: db.postDao().getPostsForChannel(channelId)
+        Log.i(TAG, "fetchPosts: channelId=$channelId (Room DAO 구현 필요)")
+        return null
+    }
+
+    private fun fetchThread(db: MattermostDatabase, serverUrl: String, rootId: String): Bundle? {
+        // TODO: db.threadDao().getThread(rootId)
+        Log.i(TAG, "fetchThread: rootId=$rootId (Room DAO 구현 필요)")
+        return null
+    }
+
+    private fun fetchNeededUsers(serverUrl: String, channelId: String): List<Bundle>? {
+        // TODO: db.userDao().getUsersForChannel(channelId)
+        Log.i(TAG, "fetchNeededUsers: channelId=$channelId (Room DAO 구현 필요)")
+        return null
+    }
+
+    private fun saveToDatabase(db: MattermostDatabase, data: Bundle, teamId: String?,
+                                channelId: String?, isCRTEnabled: Boolean) {
+        // TODO: Room DB에 알림 관련 데이터 저장 (Flutter 부팅 전 수신된 경우)
+        Log.i(TAG, "saveToDatabase: channelId=$channelId (Room DAO 구현 필요)")
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/helpers/db/GlobalDatabase.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/helpers/db/GlobalDatabase.kt
@ -0,0 +1,38 @@
+package com.tokilabs.mattermost.helpers.db
+
+import android.content.Context
+import androidx.room.Database
+import androidx.room.Room
+import androidx.room.RoomDatabase
+
+/**
+ * 전역 Room DB. 서버 목록과 디바이스 토큰 등을 저장.
+ * mattermost-mobile의 defaultDatabase (Global WatermelonDB) 대응.
+ */
+@Database(
+    entities = [GlobalEntity::class, ServerEntity::class],
+    version = 1,
+    exportSchema = false
+)
+abstract class GlobalDatabase : RoomDatabase() {
+    abstract fun globalDao(): GlobalDao
+    abstract fun serversDao(): ServersDao
+
+    companion object {
+        @Volatile private var instance: GlobalDatabase? = null
+
+        fun getInstance(context: Context): GlobalDatabase {
+            return instance ?: synchronized(this) {
+                instance ?: Room.databaseBuilder(
+                    context.applicationContext,
+                    GlobalDatabase::class.java,
+                    "mattermost_global.db"
+                )
+                    .allowMainThreadQueries()
+                    .fallbackToDestructiveMigration()
+                    .build()
+                    .also { instance = it }
+            }
+        }
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/helpers/db/GlobalEntities.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/helpers/db/GlobalEntities.kt
@ -0,0 +1,53 @@
+package com.tokilabs.mattermost.helpers.db
+
+import androidx.room.ColumnInfo
+import androidx.room.Dao
+import androidx.room.Entity
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.PrimaryKey
+import androidx.room.Query
+
+// ─── Global table (deviceToken 등 전역 설정) ────────────────────────────────
+
+@Entity(tableName = "Global")
+data class GlobalEntity(
+    @PrimaryKey val id: String,
+    val value: String
+)
+
+@Dao
+interface GlobalDao {
+    @Query("SELECT value FROM Global WHERE id = :id LIMIT 1")
+    fun getValue(id: String): String?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    fun upsert(entity: GlobalEntity)
+}
+
+// ─── Servers table (등록된 서버 목록) ─────────────────────────────────────────
+
+@Entity(tableName = "Servers")
+data class ServerEntity(
+    @PrimaryKey val url: String,
+    @ColumnInfo(name = "db_path") val dbPath: String,
+    val identifier: String? = null
+)
+
+@Dao
+interface ServersDao {
+    @Query("SELECT * FROM Servers WHERE url = :url LIMIT 1")
+    fun getServer(url: String): ServerEntity?
+
+    @Query("SELECT COUNT(*) FROM Servers")
+    fun count(): Int
+
+    @Query("SELECT url FROM Servers LIMIT 1")
+    fun getFirstUrl(): String?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    fun upsert(entity: ServerEntity)
+
+    @Query("SELECT * FROM Servers")
+    fun getAll(): List<ServerEntity>
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/helpers/db/MattermostDatabase.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/helpers/db/MattermostDatabase.kt
@ -0,0 +1,50 @@
+package com.tokilabs.mattermost.helpers.db
+
+import android.content.Context
+import androidx.room.Database
+import androidx.room.Room
+import androidx.room.RoomDatabase
+
+/**
+ * 서버별 Room DB. Config / User / System 테이블 포함.
+ * mattermost-mobile의 서버별 WatermelonDB 대응.
+ */
+@Database(
+    entities = [ConfigEntity::class, UserEntity::class, SystemEntity::class],
+    version = 1,
+    exportSchema = false
+)
+abstract class MattermostDatabase : RoomDatabase() {
+    abstract fun configDao(): ConfigDao
+    abstract fun userDao(): UserDao
+    abstract fun systemDao(): SystemDao
+
+    // ─── JWT 검증용 편의 메서드 ───────────────────────────────────────────────
+
+    fun queryConfigServerVersion(): String? = configDao().getValue("Version")
+
+    fun queryConfigSigningKey(): String? = configDao().getValue("AsymmetricSigningPublicKey")
+
+    fun getLastPictureUpdate(userId: String): Double? {
+        val id = if (userId == "me") systemDao().getValue("currentUserId") ?: userId else userId
+        return userDao().getLastPictureUpdate(id)
+    }
+
+    companion object {
+        @Volatile private val instances = mutableMapOf<String, MattermostDatabase>()
+
+        fun getInstance(context: Context, serverUrl: String): MattermostDatabase {
+            return instances.getOrPut(serverUrl) {
+                val dbName = "mattermost_server_${serverUrl.hashCode()}.db"
+                Room.databaseBuilder(
+                    context.applicationContext,
+                    MattermostDatabase::class.java,
+                    dbName
+                )
+                    .allowMainThreadQueries()
+                    .fallbackToDestructiveMigration()
+                    .build()
+            }
+        }
+    }
+}
--- a/android/app/src/main/java/com/tokilabs/mattermost/helpers/db/ServerEntities.kt
+++ b/android/app/src/main/java/com/tokilabs/mattermost/helpers/db/ServerEntities.kt
@ -0,0 +1,71 @@
+package com.tokilabs.mattermost.helpers.db
+
+import androidx.room.ColumnInfo
+import androidx.room.Dao
+import androidx.room.Entity
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.PrimaryKey
+import androidx.room.Query
+
+// ─── Config table (서버 버전, 서명키 등) ──────────────────────────────────────
+
+@Entity(tableName = "Config")
+data class ConfigEntity(
+    @PrimaryKey val id: String,
+    val value: String?
+)
+
+@Dao
+interface ConfigDao {
+    @Query("SELECT value FROM Config WHERE id = :id LIMIT 1")
+    fun getValue(id: String): String?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    fun upsert(entity: ConfigEntity)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    fun upsertAll(entities: List<ConfigEntity>)
+}
+
+// ─── User table (아바타 캐시용) ───────────────────────────────────────────────
+
+@Entity(tableName = "User")
+data class UserEntity(
+    @PrimaryKey val id: String,
+    @ColumnInfo(name = "last_picture_update") val lastPictureUpdate: Double = 0.0,
+    val username: String? = null,
+    val email: String? = null,
+    @ColumnInfo(name = "first_name") val firstName: String? = null,
+    @ColumnInfo(name = "last_name") val lastName: String? = null,
+    val roles: String? = null
+)
+
+@Dao
+interface UserDao {
+    @Query("SELECT last_picture_update FROM User WHERE id = :userId LIMIT 1")
+    fun getLastPictureUpdate(userId: String): Double?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    fun upsert(entity: UserEntity)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    fun upsertAll(entities: List<UserEntity>)
+}
+
+// ─── System table (currentUserId, currentTeamId 등) ─────────────────────────
+
+@Entity(tableName = "System")
+data class SystemEntity(
+    @PrimaryKey val id: String,
+    val value: String?
+)
+
+@Dao
+interface SystemDao {
+    @Query("SELECT value FROM System WHERE id = :id LIMIT 1")
+    fun getValue(id: String): String?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    fun upsert(entity: SystemEntity)
+}
--- a/android/app/src/main/kotlin/com/nomadcode/nomadcode/MainActivity.kt
+++ b/android/app/src/main/kotlin/com/nomadcode/nomadcode/MainActivity.kt
@ -1,5 +0,0 @@
-package com.nomadcode.nomadcode
-
-import io.flutter.embedding.android.FlutterActivity
-
-class MainActivity : FlutterActivity()
--- a/android/app/src/main/res/drawable-hdpi/ic_notif_action_reply.png
+++ b/android/app/src/main/res/drawable-hdpi/ic_notif_action_reply.png
--- a/android/app/src/main/res/drawable-mdpi/ic_notif_action_reply.png
+++ b/android/app/src/main/res/drawable-mdpi/ic_notif_action_reply.png
--- a/android/app/src/main/res/drawable-night-hdpi/ic_notif_action_reply.png
+++ b/android/app/src/main/res/drawable-night-hdpi/ic_notif_action_reply.png
--- a/android/app/src/main/res/drawable-night-mdpi/ic_notif_action_reply.png
+++ b/android/app/src/main/res/drawable-night-mdpi/ic_notif_action_reply.png
--- a/android/app/src/main/res/drawable-night-xhdpi/ic_notif_action_reply.png
+++ b/android/app/src/main/res/drawable-night-xhdpi/ic_notif_action_reply.png
--- a/android/app/src/main/res/drawable-night-xxhdpi/ic_notif_action_reply.png
+++ b/android/app/src/main/res/drawable-night-xxhdpi/ic_notif_action_reply.png
--- a/android/app/src/main/res/drawable-night-xxxhdpi/ic_notif_action_reply.png
+++ b/android/app/src/main/res/drawable-night-xxxhdpi/ic_notif_action_reply.png
--- a/android/app/src/main/res/drawable-xhdpi/ic_notif_action_reply.png
+++ b/android/app/src/main/res/drawable-xhdpi/ic_notif_action_reply.png
--- a/android/app/src/main/res/drawable-xxhdpi/ic_notif_action_reply.png
+++ b/android/app/src/main/res/drawable-xxhdpi/ic_notif_action_reply.png
--- a/android/app/src/main/res/drawable-xxxhdpi/ic_notif_action_reply.png
+++ b/android/app/src/main/res/drawable-xxxhdpi/ic_notif_action_reply.png
--- a/android/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
+++ b/android/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml
@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@mipmap/ic_launcher_background"/>
+    <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+</adaptive-icon>
--- a/android/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
+++ b/android/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml
@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@mipmap/ic_launcher_background"/>
+    <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+</adaptive-icon>
--- a/android/app/src/main/res/mipmap-hdpi/ic_launcher.png
+++ b/android/app/src/main/res/mipmap-hdpi/ic_launcher.png
--- a/android/app/src/main/res/mipmap-hdpi/ic_launcher_background.png
+++ b/android/app/src/main/res/mipmap-hdpi/ic_launcher_background.png
--- a/android/app/src/main/res/mipmap-hdpi/ic_launcher_foreground.png
+++ b/android/app/src/main/res/mipmap-hdpi/ic_launcher_foreground.png
--- a/android/app/src/main/res/mipmap-hdpi/ic_launcher_round.png
+++ b/android/app/src/main/res/mipmap-hdpi/ic_launcher_round.png
--- a/android/app/src/main/res/mipmap-hdpi/ic_notification.png
+++ b/android/app/src/main/res/mipmap-hdpi/ic_notification.png
--- a/android/app/src/main/res/mipmap-mdpi/ic_launcher.png
+++ b/android/app/src/main/res/mipmap-mdpi/ic_launcher.png
--- a/android/app/src/main/res/mipmap-mdpi/ic_launcher_background.png
+++ b/android/app/src/main/res/mipmap-mdpi/ic_launcher_background.png
--- a/android/app/src/main/res/mipmap-mdpi/ic_launcher_foreground.png
+++ b/android/app/src/main/res/mipmap-mdpi/ic_launcher_foreground.png
--- a/android/app/src/main/res/mipmap-mdpi/ic_launcher_round.png
+++ b/android/app/src/main/res/mipmap-mdpi/ic_launcher_round.png
--- a/android/app/src/main/res/mipmap-mdpi/ic_notification.png
+++ b/android/app/src/main/res/mipmap-mdpi/ic_notification.png
--- a/android/app/src/main/res/mipmap-xhdpi/ic_launcher.png
+++ b/android/app/src/main/res/mipmap-xhdpi/ic_launcher.png
--- a/android/app/src/main/res/mipmap-xhdpi/ic_launcher_background.png
+++ b/android/app/src/main/res/mipmap-xhdpi/ic_launcher_background.png
--- a/android/app/src/main/res/mipmap-xhdpi/ic_launcher_foreground.png
+++ b/android/app/src/main/res/mipmap-xhdpi/ic_launcher_foreground.png
--- a/android/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png
+++ b/android/app/src/main/res/mipmap-xhdpi/ic_launcher_round.png
--- a/android/app/src/main/res/mipmap-xhdpi/ic_notification.png
+++ b/android/app/src/main/res/mipmap-xhdpi/ic_notification.png
--- a/android/app/src/main/res/mipmap-xxhdpi/ic_launcher.png
+++ b/android/app/src/main/res/mipmap-xxhdpi/ic_launcher.png
--- a/android/app/src/main/res/mipmap-xxhdpi/ic_launcher_background.png
+++ b/android/app/src/main/res/mipmap-xxhdpi/ic_launcher_background.png
--- a/android/app/src/main/res/mipmap-xxhdpi/ic_launcher_foreground.png
+++ b/android/app/src/main/res/mipmap-xxhdpi/ic_launcher_foreground.png
--- a/android/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png
+++ b/android/app/src/main/res/mipmap-xxhdpi/ic_launcher_round.png
--- a/android/app/src/main/res/mipmap-xxhdpi/ic_notification.png
+++ b/android/app/src/main/res/mipmap-xxhdpi/ic_notification.png
--- a/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
+++ b/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
--- a/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher_background.png
+++ b/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher_background.png
--- a/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher_foreground.png
+++ b/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher_foreground.png
--- a/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png
+++ b/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png
--- a/android/app/src/main/res/mipmap-xxxhdpi/ic_notification.png
+++ b/android/app/src/main/res/mipmap-xxxhdpi/ic_notification.png
--- a/android/build.gradle.kts
+++ b/android/build.gradle.kts
@ -1,3 +1,9 @@
+buildscript {
+    dependencies {
+        classpath("com.google.gms:google-services:4.4.2")
+    }
+}
+
 allprojects {
    repositories {
        google()
--- a/lib/main.dart
+++ b/lib/main.dart
@ -1,52 +1,64 @@
+import 'package:firebase_core/firebase_core.dart';
+import 'package:firebase_messaging/firebase_messaging.dart';
 import 'package:flutter/material.dart';
+import 'services/push_notification_background.dart';
+import 'services/push_notification_service.dart';

-void main() {
-  runApp(const MyApp());
+final _navigatorKey = GlobalKey<NavigatorState>();
+
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+
+  await Firebase.initializeApp();
+
+  FirebaseMessaging.onBackgroundMessage(firebaseMessagingBackgroundHandler);
+
+  final pushService = PushNotificationService();
+  pushService.init();
+
+  runApp(MyApp(pushService: pushService));
 }

 class MyApp extends StatelessWidget {
-  const MyApp({super.key});
+  final PushNotificationService pushService;
+
+  const MyApp({super.key, required this.pushService});

-  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
-      title: 'Flutter Demo',
+      title: 'Mattermost',
+      navigatorKey: _navigatorKey,
      theme: ThemeData(
-        // This is the theme of your application.
-        //
-        // TRY THIS: Try running your application with "flutter run". You'll see
-        // the application has a purple toolbar. Then, without quitting the app,
-        // try changing the seedColor in the colorScheme below to Colors.green
-        // and then invoke "hot reload" (save your changes or press the "hot
-        // reload" button in a Flutter-supported IDE, or press "r" if you used
-        // the command line to start the app).
-        //
-        // Notice that the counter didn't reset back to zero; the application
-        // state is not lost during the reload. To reset the state, use hot
-        // restart instead.
-        //
-        // This works for code too, not just values: Most code changes can be
-        // tested with just a hot reload.
-        colorScheme: .fromSeed(seedColor: Colors.deepPurple),
+        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
      ),
-      home: const MyHomePage(title: 'Flutter Demo Home Page'),
+      home: const MyHomePage(title: 'Mattermost'),
+      builder: (context, child) {
+        // 알림 탭 시 네비게이션 콜백 등록
+        pushService.onNavigateToChannel = (serverUrl, channelId) {
+          // TODO: 채널 화면으로 이동
+          // _navigatorKey.currentState?.pushNamed(
+          //   '/channel',
+          //   arguments: {'serverUrl': serverUrl, 'channelId': channelId},
+          // );
+          print('[Nav] Navigate to channel: $channelId on $serverUrl');
+        };
+        pushService.onNavigateToThread = (serverUrl, rootId) {
+          // TODO: 스레드 화면으로 이동
+          // _navigatorKey.currentState?.pushNamed(
+          //   '/thread',
+          //   arguments: {'serverUrl': serverUrl, 'rootId': rootId},
+          // );
+          print('[Nav] Navigate to thread: $rootId on $serverUrl');
+        };
+        return child!;
+      },
    );
  }
 }

 class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});
-
-  // This widget is the home page of your application. It is stateful, meaning
-  // that it has a State object (defined below) that contains fields that affect
-  // how it looks.
-
-  // This class is the configuration for the state. It holds the values (in this
-  // case the title) provided by the parent (in this case the App widget) and
-  // used by the build method of the State. Fields in a Widget subclass are
-  // always marked "final".
-
  final String title;

  @override
@ -54,68 +66,15 @@ class MyHomePage extends StatefulWidget {
 }

 class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
-
-  void _incrementCounter() {
-    setState(() {
-      // This call to setState tells the Flutter framework that something has
-      // changed in this State, which causes it to rerun the build method below
-      // so that the display can reflect the updated values. If we changed
-      // _counter without calling setState(), then the build method would not be
-      // called again, and so nothing would appear to happen.
-      _counter++;
-    });
-  }
-
  @override
  Widget build(BuildContext context) {
-    // This method is rerun every time setState is called, for instance as done
-    // by the _incrementCounter method above.
-    //
-    // The Flutter framework has been optimized to make rerunning build methods
-    // fast, so that you can just rebuild anything that needs updating rather
-    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
-        // TRY THIS: Try changing the color here to a specific color (to
-        // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
-        // change color while the other colors stay the same.
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
-        // Here we take the value from the MyHomePage object that was created by
-        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
-      body: Center(
-        // Center is a layout widget. It takes a single child and positions it
-        // in the middle of the parent.
-        child: Column(
-          // Column is also a layout widget. It takes a list of children and
-          // arranges them vertically. By default, it sizes itself to fit its
-          // children horizontally, and tries to be as tall as its parent.
-          //
-          // Column has various properties to control how it sizes itself and
-          // how it positions its children. Here we use mainAxisAlignment to
-          // center the children vertically; the main axis here is the vertical
-          // axis because Columns are vertical (the cross axis would be
-          // horizontal).
-          //
-          // TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
-          // action in the IDE, or press "p" in the console), to see the
-          // wireframe for each widget.
-          mainAxisAlignment: .center,
-          children: [
-            const Text('You have pushed the button this many times:'),
-            Text(
-              '$_counter',
-              style: Theme.of(context).textTheme.headlineMedium,
-            ),
-          ],
-        ),
-      ),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: const Icon(Icons.add),
+      body: const Center(
+        child: Text('Mattermost Flutter'),
      ),
    );
  }
--- a/lib/services/push_notification_background.dart
+++ b/lib/services/push_notification_background.dart
@ -0,0 +1,12 @@
+import 'package:firebase_messaging/firebase_messaging.dart';
+
+/// 백그라운드 FCM 메시지 핸들러.
+/// main() 외부의 top-level 함수여야 함.
+/// push_notifications.ts의 백그라운드 처리 대응.
+@pragma('vm:entry-point')
+Future<void> firebaseMessagingBackgroundHandler(RemoteMessage message) async {
+  // NOTE: 백그라운드에서는 네이티브 Android(MattermostFirebaseMessagingService)가
+  // FCM을 직접 처리하므로 이 핸들러는 Flutter가 완전히 종료된 상태에서만 호출됨.
+  // 필요 시 최소한의 작업만 수행.
+  print('[PushNotification] Background message: ${message.messageId}');
+}
--- a/lib/services/push_notification_service.dart
+++ b/lib/services/push_notification_service.dart
@ -0,0 +1,233 @@
+import 'dart:async';
+import 'package:firebase_messaging/firebase_messaging.dart';
+import 'package:flutter/services.dart';
+
+/// 알림 타입 상수.
+class PushNotificationType {
+  static const String message = 'message';
+  static const String clear = 'clear';
+  static const String session = 'session';
+  static const String tokenRefresh = 'token_refresh';
+  static const String opened = 'opened';
+}
+
+/// 알림 탭 이벤트 데이터.
+class NotificationOpenedEvent {
+  final String? serverUrl;
+  final String? channelId;
+  final String? rootId;
+  final bool isCRTEnabled;
+
+  const NotificationOpenedEvent({
+    this.serverUrl,
+    this.channelId,
+    this.rootId,
+    this.isCRTEnabled = false,
+  });
+}
+
+/// 푸시 알림 싱글톤 서비스.
+/// mattermost-mobile의 push_notifications.ts 싱글톤 대응.
+class PushNotificationService {
+  static final PushNotificationService _instance =
+      PushNotificationService._internal();
+  factory PushNotificationService() => _instance;
+  PushNotificationService._internal();
+
+  static const EventChannel _notificationChannel =
+      EventChannel('com.tokilabs.mattermost/notifications');
+  static const MethodChannel _actionChannel =
+      MethodChannel('com.tokilabs.mattermost/notification_actions');
+
+  StreamSubscription? _channelSubscription;
+
+  /// 알림 수신 스트림 (포그라운드 메시지 등 UI에서 구독)
+  final StreamController<Map<String, dynamic>> _notificationController =
+      StreamController<Map<String, dynamic>>.broadcast();
+  Stream<Map<String, dynamic>> get onNotification =>
+      _notificationController.stream;
+
+  /// 알림 탭 스트림 (채널/스레드 네비게이션용)
+  final StreamController<NotificationOpenedEvent> _openedController =
+      StreamController<NotificationOpenedEvent>.broadcast();
+  Stream<NotificationOpenedEvent> get onNotificationOpened =>
+      _openedController.stream;
+
+  // 네비게이션 콜백 (앱 라우터에서 등록)
+  void Function(String serverUrl, String channelId)? onNavigateToChannel;
+  void Function(String serverUrl, String rootId)? onNavigateToThread;
+
+  // ─── 초기화 / 해제 ────────────────────────────────────────────────────
+
+  void init() {
+    _listenNativeChannel();
+    _listenFcmTokenRefresh();
+    _requestPermission();
+  }
+
+  void dispose() {
+    _channelSubscription?.cancel();
+    _notificationController.close();
+    _openedController.close();
+  }
+
+  // ─── 내부 초기화 ─────────────────────────────────────────────────────
+
+  void _listenNativeChannel() {
+    _channelSubscription = _notificationChannel
+        .receiveBroadcastStream()
+        .listen(
+          (dynamic event) {
+            if (event is Map) {
+              _processNotification(Map<String, dynamic>.from(event));
+            }
+          },
+          onError: (error) => print('[PushNotification] EventChannel error: $error'),
+        );
+  }
+
+  void _listenFcmTokenRefresh() {
+    FirebaseMessaging.instance.onTokenRefresh.listen((token) async {
+      await _saveDeviceToken(token);
+    });
+  }
+
+  Future<void> _requestPermission() async {
+    final settings = await FirebaseMessaging.instance.requestPermission(
+      alert: true,
+      badge: true,
+      sound: true,
+    );
+    print('[PushNotification] Permission: ${settings.authorizationStatus}');
+
+    final token = await FirebaseMessaging.instance.getToken();
+    if (token != null) await _saveDeviceToken(token);
+  }
+
+  // ─── 알림 처리 ───────────────────────────────────────────────────────
+
+  void _processNotification(Map<String, dynamic> data) {
+    final type = data['type'] as String?;
+
+    switch (type) {
+      case PushNotificationType.message:
+        _handleMessageNotification(data);
+        break;
+      case PushNotificationType.clear:
+        _handleClearNotification(data);
+        break;
+      case PushNotificationType.session:
+        _handleSessionNotification(data);
+        break;
+      case PushNotificationType.tokenRefresh:
+        final token = data['token'] as String?;
+        if (token != null) _saveDeviceToken(token);
+        break;
+      case PushNotificationType.opened:
+        _handleNotificationOpened(data);
+        break;
+    }
+
+    if (!_notificationController.isClosed) {
+      _notificationController.add(data);
+    }
+  }
+
+  void _handleMessageNotification(Map<String, dynamic> data) {
+    final isUserInteraction = data['userInteraction'] == true;
+    if (isUserInteraction) {
+      _handleNotificationOpened(data);
+    }
+    // 포그라운드 메시지는 onNotification 스트림으로 UI에서 처리
+  }
+
+  void _handleClearNotification(Map<String, dynamic> data) {
+    print('[PushNotification] Clear: channelId=${data['channel_id']}');
+    // TODO: 뱃지 카운트 초기화, 로컬 알림 상태 초기화
+  }
+
+  void _handleSessionNotification(Map<String, dynamic> data) {
+    print('[PushNotification] Session expired: serverUrl=${data['server_url']}');
+    // TODO: 해당 서버 로그아웃 처리
+    // clearAuthToken(data['server_url'])
+  }
+
+  /// 알림 탭 처리 - 채널 또는 스레드로 이동.
+  /// mattermost-mobile의 openNotification() + pushNotificationEntry() 대응.
+  void _handleNotificationOpened(Map<String, dynamic> data) {
+    final serverUrl = data['server_url'] as String?;
+    final channelId = data['channel_id'] as String?;
+    final rootId = data['root_id'] as String?;
+    final isCRTEnabled = data['is_crt_enabled'] == 'true';
+
+    print('[PushNotification] Opened: channelId=$channelId rootId=$rootId');
+
+    final event = NotificationOpenedEvent(
+      serverUrl: serverUrl,
+      channelId: channelId,
+      rootId: rootId,
+      isCRTEnabled: isCRTEnabled,
+    );
+
+    if (!_openedController.isClosed) {
+      _openedController.add(event);
+    }
+
+    // 등록된 네비게이션 콜백 호출
+    if (serverUrl == null) return;
+
+    if (isCRTEnabled && rootId != null && rootId.isNotEmpty) {
+      onNavigateToThread?.call(serverUrl, rootId);
+    } else if (channelId != null) {
+      onNavigateToChannel?.call(serverUrl, channelId);
+    }
+  }
+
+  // ─── 인증 토큰 관리 ──────────────────────────────────────────────────
+
+  /// 로그인 성공 시 호출. 서버 URL + Bearer 토큰을 네이티브에 저장.
+  /// 이후 ReceiptDelivery(ACK), NotificationReplyBroadcastReceiver(답장) API 호출에 사용.
+  Future<void> setAuthToken(String serverUrl, String token,
+      {String? identifier}) async {
+    try {
+      await _actionChannel.invokeMethod('setAuthToken', {
+        'serverUrl': serverUrl,
+        'token': token,
+        if (identifier != null) 'identifier': identifier,
+      });
+      print('[PushNotification] Auth token saved for $serverUrl');
+    } catch (e) {
+      print('[PushNotification] Failed to save auth token: $e');
+    }
+  }
+
+  /// 로그아웃 시 호출.
+  Future<void> clearAuthToken(String serverUrl) async {
+    try {
+      await _actionChannel.invokeMethod('clearAuthToken', {'serverUrl': serverUrl});
+    } catch (e) {
+      print('[PushNotification] Failed to clear auth token: $e');
+    }
+  }
+
+  /// FCM 디바이스 토큰 저장 (네이티브 DB에 android-react-native-v2:{token}: 형식으로 저장).
+  Future<void> _saveDeviceToken(String token) async {
+    try {
+      const prefix = 'android-react-native-v2';
+      final formattedToken = '$prefix:$token:';
+      await _actionChannel
+          .invokeMethod('saveDeviceToken', {'token': formattedToken});
+      print('[PushNotification] Device token saved');
+    } catch (e) {
+      print('[PushNotification] Failed to save device token: $e');
+    }
+  }
+
+  Future<String?> getDeviceToken() async {
+    try {
+      return await _actionChannel.invokeMethod<String>('getDeviceToken');
+    } catch (e) {
+      return null;
+    }
+  }
+}
--- a/macos/Flutter/GeneratedPluginRegistrant.swift
+++ b/macos/Flutter/GeneratedPluginRegistrant.swift
@ -5,6 +5,12 @@
 import FlutterMacOS
 import Foundation

+import firebase_core
+import firebase_messaging
+import flutter_local_notifications

 func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
+  FLTFirebaseCorePlugin.register(with: registry.registrar(forPlugin: "FLTFirebaseCorePlugin"))
+  FLTFirebaseMessagingPlugin.register(with: registry.registrar(forPlugin: "FLTFirebaseMessagingPlugin"))
+  FlutterLocalNotificationsPlugin.register(with: registry.registrar(forPlugin: "FlutterLocalNotificationsPlugin"))
 }
--- a/pubspec.lock
+++ b/pubspec.lock
@ -1,6 +1,22 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  _flutterfire_internals:
+    dependency: transitive
+    description:
+      name: _flutterfire_internals
+      sha256: ff0a84a2734d9e1089f8aedd5c0af0061b82fb94e95260d943404e0ef2134b11
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.59"
+  args:
+    dependency: transitive
+    description:
+      name: args
+      sha256: d0481093c50b1da8910eb0bb301626d4d8eb7284aa739614d2b394ee09e3ea04
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.7.0"
  async:
    dependency: transitive
    description:
@ -49,6 +65,14 @@ packages:
      url: "https://pub.dev"
    source: hosted
    version: "1.0.8"
+  dbus:
+    dependency: transitive
+    description:
+      name: dbus
+      sha256: d0c98dcd4f5169878b6cf8f6e0a52403a9dff371a3e2f019697accbf6f44a270
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.7.12"
  fake_async:
    dependency: transitive
    description:
@ -57,6 +81,62 @@ packages:
      url: "https://pub.dev"
    source: hosted
    version: "1.3.3"
+  ffi:
+    dependency: transitive
+    description:
+      name: ffi
+      sha256: "6d7fd89431262d8f3125e81b50d3847a091d846eafcd4fdb88dd06f36d705a45"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
+  firebase_core:
+    dependency: "direct main"
+    description:
+      name: firebase_core
+      sha256: "7be63a3f841fc9663342f7f3a011a42aef6a61066943c90b1c434d79d5c995c5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.15.2"
+  firebase_core_platform_interface:
+    dependency: transitive
+    description:
+      name: firebase_core_platform_interface
+      sha256: cccb4f572325dc14904c02fcc7db6323ad62ba02536833dddb5c02cac7341c64
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.0.2"
+  firebase_core_web:
+    dependency: transitive
+    description:
+      name: firebase_core_web
+      sha256: "0ed0dc292e8f9ac50992e2394e9d336a0275b6ae400d64163fdf0a8a8b556c37"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.24.1"
+  firebase_messaging:
+    dependency: "direct main"
+    description:
+      name: firebase_messaging
+      sha256: "60be38574f8b5658e2f22b7e311ff2064bea835c248424a383783464e8e02fcc"
+      url: "https://pub.dev"
+    source: hosted
+    version: "15.2.10"
+  firebase_messaging_platform_interface:
+    dependency: transitive
+    description:
+      name: firebase_messaging_platform_interface
+      sha256: "685e1771b3d1f9c8502771ccc9f91485b376ffe16d553533f335b9183ea99754"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.6.10"
+  firebase_messaging_web:
+    dependency: transitive
+    description:
+      name: firebase_messaging_web
+      sha256: "0d1be17bc89ed3ff5001789c92df678b2e963a51b6fa2bdb467532cc9dbed390"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.10.10"
  flutter:
    dependency: "direct main"
    description: flutter
@ -70,11 +150,56 @@ packages:
      url: "https://pub.dev"
    source: hosted
    version: "6.0.0"
+  flutter_local_notifications:
+    dependency: "direct main"
+    description:
+      name: flutter_local_notifications
+      sha256: ef41ae901e7529e52934feba19ed82827b11baa67336829564aeab3129460610
+      url: "https://pub.dev"
+    source: hosted
+    version: "18.0.1"
+  flutter_local_notifications_linux:
+    dependency: transitive
+    description:
+      name: flutter_local_notifications_linux
+      sha256: "8f685642876742c941b29c32030f6f4f6dacd0e4eaecb3efbb187d6a3812ca01"
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.0.0"
+  flutter_local_notifications_platform_interface:
+    dependency: transitive
+    description:
+      name: flutter_local_notifications_platform_interface
+      sha256: "6c5b83c86bf819cdb177a9247a3722067dd8cc6313827ce7c77a4b238a26fd52"
+      url: "https://pub.dev"
+    source: hosted
+    version: "8.0.0"
  flutter_test:
    dependency: "direct dev"
    description: flutter
    source: sdk
    version: "0.0.0"
+  flutter_web_plugins:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  http:
+    dependency: transitive
+    description:
+      name: http
+      sha256: "87721a4a50b19c7f1d49001e51409bddc46303966ce89a65af4f4e6004896412"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.6.0"
+  http_parser:
+    dependency: transitive
+    description:
+      name: http_parser
+      sha256: "178d74305e7866013777bab2c3d8726205dc5a4dd935297175b19a23a2e66571"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.1.2"
  leak_tracker:
    dependency: transitive
    description:
@ -111,10 +236,10 @@ packages:
    dependency: transitive
    description:
      name: matcher
-      sha256: "12956d0ad8390bbcc63ca2e1469c0619946ccb52809807067a7020d57e647aa6"
+      sha256: dc0b7dc7651697ea4ff3e69ef44b0407ea32c487a39fff6a4004fa585e901861
      url: "https://pub.dev"
    source: hosted
-    version: "0.12.18"
+    version: "0.12.19"
  material_color_utilities:
    dependency: transitive
    description:
@ -139,6 +264,22 @@ packages:
      url: "https://pub.dev"
    source: hosted
    version: "1.9.1"
+  petitparser:
+    dependency: transitive
+    description:
+      name: petitparser
+      sha256: "91bd59303e9f769f108f8df05e371341b15d59e995e6806aefab827b58336675"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.0.2"
+  plugin_platform_interface:
+    dependency: transitive
+    description:
+      name: plugin_platform_interface
+      sha256: "4820fbfdb9478b1ebae27888254d445073732dae3d6ea81f0b7e06d5dedc3f02"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.8"
  sky_engine:
    dependency: transitive
    description: flutter
@ -188,10 +329,26 @@ packages:
    dependency: transitive
    description:
      name: test_api
-      sha256: "93167629bfc610f71560ab9312acdda4959de4df6fac7492c89ff0d3886f6636"
+      sha256: "8161c84903fd860b26bfdefb7963b3f0b68fee7adea0f59ef805ecca346f0c7a"
      url: "https://pub.dev"
    source: hosted
-    version: "0.7.9"
+    version: "0.7.10"
+  timezone:
+    dependency: transitive
+    description:
+      name: timezone
+      sha256: dd14a3b83cfd7cb19e7888f1cbc20f258b8d71b54c06f79ac585f14093a287d1
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.10.1"
+  typed_data:
+    dependency: transitive
+    description:
+      name: typed_data
+      sha256: f9049c039ebfeb4cf7a7104a675823cd72dba8297f264b6637062516699fa006
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.0"
  vector_math:
    dependency: transitive
    description:
@ -208,6 +365,30 @@ packages:
      url: "https://pub.dev"
    source: hosted
    version: "15.0.2"
+  web:
+    dependency: transitive
+    description:
+      name: web
+      sha256: "868d88a33d8a87b18ffc05f9f030ba328ffefba92d6c127917a2ba740f9cfe4a"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.1"
+  xdg_directories:
+    dependency: transitive
+    description:
+      name: xdg_directories
+      sha256: "7a3f37b05d989967cdddcbb571f1ea834867ae2faa29725fd085180e0883aa15"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.0"
+  xml:
+    dependency: transitive
+    description:
+      name: xml
+      sha256: "971043b3a0d3da28727e40ed3e0b5d18b742fa5a68665cca88e74b7876d5e025"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.6.1"
 sdks:
  dart: ">=3.11.0 <4.0.0"
-  flutter: ">=3.18.0-18.0.pre.54"
+  flutter: ">=3.22.0"
--- a/pubspec.yaml
+++ b/pubspec.yaml
@ -35,6 +35,13 @@ dependencies:
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^1.0.8

+  # Firebase
+  firebase_core: ^3.13.0
+  firebase_messaging: ^15.2.5
+
+  # Local notifications (foreground display)
+  flutter_local_notifications: ^18.0.1
+
 dev_dependencies:
  flutter_test:
    sdk: flutter
--- a/windows/flutter/generated_plugin_registrant.cc
+++ b/windows/flutter/generated_plugin_registrant.cc
@ -6,6 +6,9 @@

 #include "generated_plugin_registrant.h"

+#include <firebase_core/firebase_core_plugin_c_api.h>

 void RegisterPlugins(flutter::PluginRegistry* registry) {
+  FirebaseCorePluginCApiRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("FirebaseCorePluginCApi"));
 }
--- a/windows/flutter/generated_plugins.cmake
+++ b/windows/flutter/generated_plugins.cmake
@ -3,6 +3,7 @@
 #

 list(APPEND FLUTTER_PLUGIN_LIST
+  firebase_core
 )

 list(APPEND FLUTTER_FFI_PLUGIN_LIST