diff --git a/lib/presentation/chat_screen/chat_screen.dart b/lib/presentation/chat_screen/chat_screen.dart
index 321f8bb..24be257 100644
--- a/lib/presentation/chat_screen/chat_screen.dart
+++ b/lib/presentation/chat_screen/chat_screen.dart
@@ -68,14 +68,20 @@ class _ChatScreenState extends State<ChatScreen> {
                 child: CustomProgressIndicatorWidget(),
               );
             }
-            print(_chatStore.chatThreads);
             return ListView.builder(
               controller: _controller,
               itemCount:
-                  _chatStore.chatThreads[chatThreadIndex].messages.length,
+                  _chatStore.chatThreads[chatThreadIndex].messages.length +
+                      (_chatStore.isLoading ? 1 : 0),
               shrinkWrap: true,
               padding: EdgeInsets.zero,
               itemBuilder: (context, index) {
+                if (index > 0 &&
+                    index ==
+                        _chatStore
+                            .chatThreads[chatThreadIndex].messages.length) {
+                  return CustomProgressIndicatorWidget();
+                }
                 return Container(
                   padding: EdgeInsets.only(
                       left: (_chatStore.chatThreads[chatThreadIndex]
@@ -158,7 +164,7 @@ class _ChatScreenState extends State<ChatScreen> {
             );
           }),
         ),
-        ChatInput(onSend: () {}),
+        ChatInput(onSend: _chatStore.sendMessage),
       ],
     );
   }
diff --git a/lib/presentation/chat_screen/store/chat_store.dart b/lib/presentation/chat_screen/store/chat_store.dart
index 9fc65a7..c98d9a1 100644
--- a/lib/presentation/chat_screen/store/chat_store.dart
+++ b/lib/presentation/chat_screen/store/chat_store.dart
@@ -4,6 +4,7 @@ import 'package:boilerplate/domain/entity/message/message.dart';
 import 'package:boilerplate/domain/entity/message/message_with_time.dart';
 import 'package:boilerplate/domain/usecase/message/get_all_chat_threads_usecase.dart';
 import 'package:boilerplate/domain/usecase/message/send_message_usecase.dart';
+import 'package:boilerplate/domain/usecase/message/update_chat_thread_usecase.dart';
 
 import 'package:mobx/mobx.dart';
 
@@ -17,6 +18,7 @@ abstract class _ChatStore with Store {
     this.errorStore,
     this._sendMessageUseCase,
     this._getAllChatThreadsUseCase,
+    this._updateChatThreadUseCase,
   ) {
     // load all chat threads
     getAllChatThreads();
@@ -27,6 +29,7 @@ abstract class _ChatStore with Store {
   // use cases:-----------------------------------------------------------------
   final SendMessageUseCase _sendMessageUseCase;
   final GetAllChatThreadsUseCase _getAllChatThreadsUseCase;
+  final UpdateChatThreadUseCase _updateChatThreadUseCase;
 
   // store for handling error messages
   final ErrorStore errorStore;
@@ -58,8 +61,13 @@ abstract class _ChatStore with Store {
   @observable
   ObservableFuture<Message?> sendMessageFuture = ObservableFuture.value(null);
 
+  @observable
+  ObservableFuture<int?> updateChatThreadFuture = ObservableFuture.value(null);
+
   @computed
-  bool get isLoading => sendMessageFuture.status == FutureStatus.pending;
+  bool get isLoading =>
+      sendMessageFuture.status == FutureStatus.pending ||
+      updateChatThreadFuture.status == FutureStatus.pending;
 
   @computed
   bool get isLoadingChatThreads =>
@@ -110,18 +118,20 @@ abstract class _ChatStore with Store {
 
     await future.then((value) async {
       print('response message ${value.toMap()}');
-      // TODO: update chat thread in db
-      // await _saveChatThreadUseCase.call(
-      //   params: ChatThread(
-      //     id: time.millisecondsSinceEpoch,
-      //     subject: message.content,
-      //     messages: [
-      //       MessageWithTime(message, time),
-      //       MessageWithTime(value, time),
-      //     ],
-      //   ),
-      // );
-      this.success = true;
+      final newChatThread =
+          chatThreads.firstWhere((element) => element.id == id);
+      newChatThread.messages.add(
+        MessageWithTime(
+          value,
+          DateTime.now(),
+        ),
+      );
+      print(newChatThread);
+      final future = _updateChatThreadUseCase.call(
+        params: newChatThread,
+      );
+      updateChatThreadFuture = ObservableFuture(future);
+      await future.then((value) => {this.success = true});
     }).catchError((e) {
       print(e);
       this.success = false;
diff --git a/lib/presentation/di/module/store_module.dart b/lib/presentation/di/module/store_module.dart
index 5330db9..1c1a5d4 100644
--- a/lib/presentation/di/module/store_module.dart
+++ b/lib/presentation/di/module/store_module.dart
@@ -6,6 +6,7 @@ import 'package:boilerplate/domain/repository/setting/setting_repository.dart';
 import 'package:boilerplate/domain/usecase/message/get_all_chat_threads_usecase.dart';
 import 'package:boilerplate/domain/usecase/message/save_chat_thread_usecase.dart';
 import 'package:boilerplate/domain/usecase/message/send_message_usecase.dart';
+import 'package:boilerplate/domain/usecase/message/update_chat_thread_usecase.dart';
 import 'package:boilerplate/domain/usecase/post/get_post_usecase.dart';
 import 'package:boilerplate/domain/usecase/user/is_logged_in_usecase.dart';
 import 'package:boilerplate/domain/usecase/user/login_usecase.dart';
@@ -73,6 +74,7 @@ mixin StoreModule {
         getIt<ErrorStore>(),
         getIt<SendMessageUseCase>(),
         getIt<GetAllChatThreadsUseCase>(),
+        getIt<UpdateChatThreadUseCase>(),
       ),
     );
   }