diff --git a/lib/core/api/auth/datasources/auth_remote_datasource.dart b/lib/core/api/auth/datasources/auth_remote_datasource.dart
index 4c1bfd9..bd054e0 100644
--- a/lib/core/api/auth/datasources/auth_remote_datasource.dart
+++ b/lib/core/api/auth/datasources/auth_remote_datasource.dart
@@ -5,13 +5,15 @@ import 'package:waterbus_sdk/constants/api_enpoints.dart';
 import 'package:waterbus_sdk/constants/http_status_code.dart';
 import 'package:waterbus_sdk/core/api/auth/datasources/auth_local_datasource.dart';
 import 'package:waterbus_sdk/core/api/base/base_remote_data.dart';
+import 'package:waterbus_sdk/types/error/failures.dart';
 import 'package:waterbus_sdk/types/models/auth_payload_model.dart';
 import 'package:waterbus_sdk/types/models/user_model.dart';
+import 'package:waterbus_sdk/types/result.dart';
 
 abstract class AuthRemoteDataSource {
   Future<(String?, String?)> refreshToken();
-  Future<User?> signInWithSocial(AuthPayloadModel authPayload);
-  Future<bool> logOut();
+  Future<Result<User>> signInWithSocial(AuthPayloadModel authPayload);
+  Future<Result<bool>> logOut();
 }
 
 @LazySingleton(as: AuthRemoteDataSource)
@@ -22,7 +24,7 @@ class AuthRemoteDataSourceImpl extends AuthRemoteDataSource {
   AuthRemoteDataSourceImpl(this._baseRemoteData, this._localDataSource);
 
   @override
-  Future<User?> signInWithSocial(AuthPayloadModel authPayload) async {
+  Future<Result<User>> signInWithSocial(AuthPayloadModel authPayload) async {
     final Map<String, dynamic> body = authPayload.toMap();
 
     final Response response = await _baseRemoteData.postRoute(
@@ -39,10 +41,10 @@ class AuthRemoteDataSourceImpl extends AuthRemoteDataSource {
         refreshToken: refreshToken,
       );
 
-      return User.fromMap(response.data['user']);
+      return Result.success(User.fromMap(response.data['user']));
     }
 
-    return null;
+    return Result.failure(ServerFailure());
   }
 
   @override
@@ -61,11 +63,15 @@ class AuthRemoteDataSourceImpl extends AuthRemoteDataSource {
   }
 
   @override
-  Future<bool> logOut() async {
+  Future<Result<bool>> logOut() async {
     final Response response = await _baseRemoteData.deleteRoute(
       ApiEndpoints.auth,
     );
 
-    return response.statusCode == StatusCode.noContent;
+    if (response.statusCode == StatusCode.noContent) {
+      return Result.success(true);
+    }
+
+    return Result.failure(ServerFailure());
   }
 }
diff --git a/lib/core/api/auth/repositories/auth_repository.dart b/lib/core/api/auth/repositories/auth_repository.dart
index 21269d3..46e9249 100644
--- a/lib/core/api/auth/repositories/auth_repository.dart
+++ b/lib/core/api/auth/repositories/auth_repository.dart
@@ -2,13 +2,15 @@ import 'package:injectable/injectable.dart';
 
 import 'package:waterbus_sdk/core/api/auth/datasources/auth_local_datasource.dart';
 import 'package:waterbus_sdk/core/api/auth/datasources/auth_remote_datasource.dart';
+import 'package:waterbus_sdk/types/error/failures.dart';
 import 'package:waterbus_sdk/types/models/auth_payload_model.dart';
 import 'package:waterbus_sdk/types/models/user_model.dart';
+import 'package:waterbus_sdk/types/result.dart';
 
 abstract class AuthRepository {
-  Future<bool> refreshToken();
-  Future<User?> loginWithSocial(AuthPayloadModel params);
-  Future<bool> logOut();
+  Future<Result<bool>> refreshToken();
+  Future<Result<User>> loginWithSocial(AuthPayloadModel params);
+  Future<Result<bool>> logOut();
 }
 
 @LazySingleton(as: AuthRepository)
@@ -19,33 +21,36 @@ class AuthRepositoryImpl extends AuthRepository {
   AuthRepositoryImpl(this._localDataSource, this._remoteDataSource);
 
   @override
-  Future<User?> loginWithSocial(AuthPayloadModel params) async {
-    final User? response = await _remoteDataSource.signInWithSocial(params);
+  Future<Result<User>> loginWithSocial(AuthPayloadModel params) async {
+    final Result<User> result =
+        await _remoteDataSource.signInWithSocial(params);
 
-    return response;
+    return result;
   }
 
   @override
-  Future<bool> refreshToken() async {
+  Future<Result<bool>> refreshToken() async {
     final (String? accessToken, String? refreshToken) =
         await _remoteDataSource.refreshToken();
 
-    if (accessToken == null || refreshToken == null) return false;
+    if (accessToken == null || refreshToken == null) {
+      return Result.failure(ServerFailure());
+    }
 
     _localDataSource.saveTokens(
       accessToken: accessToken,
       refreshToken: refreshToken,
     );
 
-    return true;
+    return Result.success(true);
   }
 
   @override
-  Future<bool> logOut() async {
-    final bool isSignedOut = await _remoteDataSource.logOut();
+  Future<Result<bool>> logOut() async {
+    final Result<bool> result = await _remoteDataSource.logOut();
 
     _localDataSource.clearToken();
 
-    return isSignedOut;
+    return result;
   }
 }
diff --git a/lib/core/api/meetings/datasources/meeting_remote_datesource.dart b/lib/core/api/meetings/datasources/meeting_remote_datesource.dart
index 286e157..01598f6 100644
--- a/lib/core/api/meetings/datasources/meeting_remote_datesource.dart
+++ b/lib/core/api/meetings/datasources/meeting_remote_datesource.dart
@@ -4,29 +4,34 @@ import 'package:injectable/injectable.dart';
 import 'package:waterbus_sdk/constants/api_enpoints.dart';
 import 'package:waterbus_sdk/constants/http_status_code.dart';
 import 'package:waterbus_sdk/core/api/base/base_remote_data.dart';
+import 'package:waterbus_sdk/types/models/exceptions/exceptions.dart';
 import 'package:waterbus_sdk/types/models/meeting_model.dart';
 import 'package:waterbus_sdk/types/models/record_model.dart';
+import 'package:waterbus_sdk/types/result.dart';
 
 abstract class MeetingRemoteDataSource {
-  Future<Meeting?> createMeeting({
+  Future<Result<Meeting>> createMeeting({
     required Meeting meeting,
     required String password,
   });
-  Future<bool> updateMeeting({
+  Future<Result<bool>> updateMeeting({
     required Meeting meeting,
     required String password,
   });
-  Future<Meeting?> joinMeetingWithPassword({
+  Future<Result<Meeting>> joinMeetingWithPassword({
     required Meeting meeting,
     required String password,
   });
-  Future<Meeting?> joinMeetingWithoutPassword({
+  Future<Result<Meeting>> joinMeetingWithoutPassword({
     required Meeting meeting,
   });
-  Future<Meeting?> getInfoMeeting(int code);
-  Future<List<RecordModel>> getRecords({required int skip, required int limit});
-  Future<int?> startRecord(int roomId);
-  Future<bool> stopRecord(int roomId);
+  Future<Result<Meeting>> getInfoMeeting(int code);
+  Future<Result<List<RecordModel>>> getRecords({
+    required int skip,
+    required int limit,
+  });
+  Future<Result<int>> startRecord(int roomId);
+  Future<Result<bool>> stopRecord(int roomId);
 }
 
 @LazySingleton(as: MeetingRemoteDataSource)
@@ -37,7 +42,7 @@ class MeetingRemoteDataSourceImpl extends MeetingRemoteDataSource {
   );
 
   @override
-  Future<Meeting?> createMeeting({
+  Future<Result<Meeting>> createMeeting({
     required Meeting meeting,
     required String password,
   }) async {
@@ -48,14 +53,14 @@ class MeetingRemoteDataSourceImpl extends MeetingRemoteDataSource {
 
     if (response.statusCode == StatusCode.created) {
       final Map<String, dynamic> rawData = response.data;
-      return Meeting.fromMap(rawData);
+      return Result.success(Meeting.fromMap(rawData));
     }
 
-    return null;
+    return Result.failure(response.data['message'].toString().meetingException);
   }
 
   @override
-  Future<Meeting?> getInfoMeeting(int code) async {
+  Future<Result<Meeting>> getInfoMeeting(int code) async {
     final Response response = await _remoteData.getRoute(
       '${ApiEndpoints.meetings}/$code',
     );
@@ -63,14 +68,14 @@ class MeetingRemoteDataSourceImpl extends MeetingRemoteDataSource {
     if (response.statusCode == StatusCode.ok &&
         response.data.toString().isNotEmpty) {
       final Map<String, dynamic> rawData = response.data;
-      return Meeting.fromMap(rawData);
+      return Result.success(Meeting.fromMap(rawData));
     }
 
-    return null;
+    return Result.failure(response.data['message'].toString().meetingException);
   }
 
   @override
-  Future<Meeting?> joinMeetingWithPassword({
+  Future<Result<Meeting>> joinMeetingWithPassword({
     required Meeting meeting,
     required String password,
   }) async {
@@ -81,16 +86,18 @@ class MeetingRemoteDataSourceImpl extends MeetingRemoteDataSource {
 
     if (response.statusCode == StatusCode.created) {
       final Map<String, dynamic> rawData = response.data;
-      return Meeting.fromMap(rawData).copyWith(
-        latestJoinedAt: DateTime.now(),
+      return Result.success(
+        Meeting.fromMap(rawData).copyWith(
+          latestJoinedAt: DateTime.now(),
+        ),
       );
     }
 
-    return null;
+    return Result.failure(response.data['message'].toString().meetingException);
   }
 
   @override
-  Future<Meeting?> joinMeetingWithoutPassword({
+  Future<Result<Meeting>> joinMeetingWithoutPassword({
     required Meeting meeting,
   }) async {
     final Response response = await _remoteData.postRoute(
@@ -99,16 +106,18 @@ class MeetingRemoteDataSourceImpl extends MeetingRemoteDataSource {
 
     if (response.statusCode == StatusCode.created) {
       final Map<String, dynamic> rawData = response.data;
-      return Meeting.fromMap(rawData).copyWith(
-        latestJoinedAt: DateTime.now(),
+      return Result.success(
+        Meeting.fromMap(rawData).copyWith(
+          latestJoinedAt: DateTime.now(),
+        ),
       );
     }
 
-    return null;
+    return Result.failure(response.data['message'].toString().meetingException);
   }
 
   @override
-  Future<bool> updateMeeting({
+  Future<Result<bool>> updateMeeting({
     required Meeting meeting,
     required String password,
   }) async {
@@ -117,11 +126,15 @@ class MeetingRemoteDataSourceImpl extends MeetingRemoteDataSource {
       meeting.toMapCreate(password: password),
     );
 
-    return response.statusCode == StatusCode.ok;
+    if (response.statusCode == StatusCode.ok) {
+      return Result.success(true);
+    }
+
+    return Result.failure(response.data['message'].toString().meetingException);
   }
 
   @override
-  Future<List<RecordModel>> getRecords({
+  Future<Result<List<RecordModel>>> getRecords({
     required int skip,
     required int limit,
   }) async {
@@ -129,33 +142,39 @@ class MeetingRemoteDataSourceImpl extends MeetingRemoteDataSource {
 
     if (response.statusCode == StatusCode.ok) {
       final List rawData = response.data;
-      return rawData.map((data) => RecordModel.fromMap(data)).toList();
+      return Result.success(
+        rawData.map((data) => RecordModel.fromMap(data)).toList(),
+      );
     }
 
-    return [];
+    return Result.failure(response.data['message'].toString().meetingException);
   }
 
   @override
-  Future<int?> startRecord(int roomId) async {
+  Future<Result<int>> startRecord(int roomId) async {
     final Response response = await _remoteData.postRoute(
       ApiEndpoints.startRecord,
       queryParameters: {"code": roomId},
     );
 
     if (response.statusCode == StatusCode.created) {
-      return response.data['id'];
+      return Result.success(response.data['id']);
     }
 
-    return null;
+    return Result.failure(response.data['message'].toString().meetingException);
   }
 
   @override
-  Future<bool> stopRecord(int roomId) async {
+  Future<Result<bool>> stopRecord(int roomId) async {
     final Response response = await _remoteData.postRoute(
       ApiEndpoints.stopRecord,
       queryParameters: {"code": roomId},
     );
 
-    return response.statusCode == StatusCode.created;
+    if (response.statusCode == StatusCode.created) {
+      return Result.success(true);
+    }
+
+    return Result.failure(response.data['message'].toString().meetingException);
   }
 }
diff --git a/lib/core/api/meetings/repositories/meeting_repository.dart b/lib/core/api/meetings/repositories/meeting_repository.dart
index 61197da..11dbf13 100644
--- a/lib/core/api/meetings/repositories/meeting_repository.dart
+++ b/lib/core/api/meetings/repositories/meeting_repository.dart
@@ -4,20 +4,24 @@ import 'package:waterbus_sdk/core/api/meetings/datasources/meeting_remote_dateso
 import 'package:waterbus_sdk/types/index.dart';
 import 'package:waterbus_sdk/types/models/create_meeting_params.dart';
 import 'package:waterbus_sdk/types/models/record_model.dart';
+import 'package:waterbus_sdk/types/result.dart';
 
 abstract class MeetingRepository {
-  Future<Meeting?> createMeeting(CreateMeetingParams params);
-  Future<Meeting?> updateMeeting(CreateMeetingParams params);
-  Future<Meeting?> joinMeetingWithPassword(
+  Future<Result<Meeting>> createMeeting(CreateMeetingParams params);
+  Future<Result<bool>> updateMeeting(CreateMeetingParams params);
+  Future<Result<Meeting>> joinMeetingWithPassword(
     CreateMeetingParams params,
   );
-  Future<Meeting?> joinMeetingWithoutPassword(
+  Future<Result<Meeting>> joinMeetingWithoutPassword(
     CreateMeetingParams params,
   );
-  Future<Meeting?> getInfoMeeting(int code);
-  Future<List<RecordModel>> getRecords({required int skip, required int limit});
-  Future<int?> startRecord(int roomId);
-  Future<bool> stopRecord(int roomId);
+  Future<Result<Meeting>> getInfoMeeting(int code);
+  Future<Result<List<RecordModel>>> getRecords({
+    required int skip,
+    required int limit,
+  });
+  Future<Result<int>> startRecord(int roomId);
+  Future<Result<bool>> stopRecord(int roomId);
 }
 
 @LazySingleton(as: MeetingRepository)
@@ -27,76 +31,79 @@ class MeetingRepositoryImpl extends MeetingRepository {
   MeetingRepositoryImpl(this._remoteDataSource);
 
   @override
-  Future<Meeting?> createMeeting(
+  Future<Result<Meeting>> createMeeting(
     CreateMeetingParams params,
   ) async {
-    Meeting? meeting = await _remoteDataSource.createMeeting(
+    Result<Meeting> result = await _remoteDataSource.createMeeting(
       meeting: params.meeting,
       password: params.password,
     );
 
-    if (meeting == null) return null;
+    if (result.isFailure) return result;
 
-    meeting = findMyParticipantObject(meeting, userId: params.userId);
+    result = Result.success(
+      findMyParticipantObject(result.value!, userId: params.userId),
+    );
 
-    return meeting;
+    return result;
   }
 
   @override
-  Future<Meeting?> getInfoMeeting(int code) async {
-    final Meeting? meeting = await _remoteDataSource.getInfoMeeting(code);
-
-    if (meeting == null) return null;
+  Future<Result<Meeting>> getInfoMeeting(int code) async {
+    final Result<Meeting> meeting =
+        await _remoteDataSource.getInfoMeeting(code);
 
     return meeting;
   }
 
   @override
-  Future<Meeting?> joinMeetingWithPassword(
+  Future<Result<Meeting>> joinMeetingWithPassword(
     CreateMeetingParams params,
   ) async {
-    Meeting? meeting = await _remoteDataSource.joinMeetingWithPassword(
+    Result<Meeting> result = await _remoteDataSource.joinMeetingWithPassword(
       meeting: params.meeting,
       password: params.password,
     );
 
-    if (meeting == null) return null;
+    if (result.isFailure) return result;
 
-    meeting = findMyParticipantObject(meeting, userId: params.userId);
+    result = Result.success(
+      findMyParticipantObject(result.value!, userId: params.userId),
+    );
 
-    return meeting;
+    return result;
   }
 
   @override
-  Future<Meeting?> joinMeetingWithoutPassword(
+  Future<Result<Meeting>> joinMeetingWithoutPassword(
     CreateMeetingParams params,
   ) async {
-    Meeting? meeting = await _remoteDataSource.joinMeetingWithoutPassword(
+    Result<Meeting> result = await _remoteDataSource.joinMeetingWithoutPassword(
       meeting: params.meeting,
     );
 
-    if (meeting == null) return null;
+    if (result.isFailure) return result;
 
-    meeting = findMyParticipantObject(
-      meeting,
-      userId: params.userId,
+    result = Result.success(
+      findMyParticipantObject(
+        result.value!,
+        userId: params.userId,
+      ),
     );
 
-    return meeting;
+    return result;
   }
 
   @override
-  Future<Meeting?> updateMeeting(
+  Future<Result<bool>> updateMeeting(
     CreateMeetingParams params,
   ) async {
-    final bool isUpdateSucceed = await _remoteDataSource.updateMeeting(
+    final Result<bool> isUpdateSucceed = await _remoteDataSource.updateMeeting(
       meeting: params.meeting,
       password: params.password,
     );
 
-    if (!isUpdateSucceed) return null;
-
-    return params.meeting;
+    return isUpdateSucceed;
   }
 
   // MARK: private
@@ -123,7 +130,7 @@ class MeetingRepositoryImpl extends MeetingRepository {
   }
 
   @override
-  Future<List<RecordModel>> getRecords({
+  Future<Result<List<RecordModel>>> getRecords({
     required int skip,
     required int limit,
   }) async {
@@ -131,12 +138,12 @@ class MeetingRepositoryImpl extends MeetingRepository {
   }
 
   @override
-  Future<int?> startRecord(int roomId) async {
+  Future<Result<int>> startRecord(int roomId) async {
     return await _remoteDataSource.startRecord(roomId);
   }
 
   @override
-  Future<bool> stopRecord(int roomId) async {
+  Future<Result<bool>> stopRecord(int roomId) async {
     return await _remoteDataSource.stopRecord(roomId);
   }
 }
diff --git a/lib/core/api/user/datasources/user_remote_datasource.dart b/lib/core/api/user/datasources/user_remote_datasource.dart
index b59a9a9..806cb1e 100644
--- a/lib/core/api/user/datasources/user_remote_datasource.dart
+++ b/lib/core/api/user/datasources/user_remote_datasource.dart
@@ -10,20 +10,23 @@ import 'package:injectable/injectable.dart';
 import 'package:waterbus_sdk/constants/api_enpoints.dart';
 import 'package:waterbus_sdk/constants/http_status_code.dart';
 import 'package:waterbus_sdk/core/api/base/base_remote_data.dart';
+import 'package:waterbus_sdk/types/error/failures.dart';
+import 'package:waterbus_sdk/types/models/exceptions/exceptions.dart';
 import 'package:waterbus_sdk/types/models/user_model.dart';
+import 'package:waterbus_sdk/types/result.dart';
 
 abstract class UserRemoteDataSource {
-  Future<User?> getUserProfile();
-  Future<bool> updateUserProfile(User user);
-  Future<bool> updateUsername(String username);
-  Future<bool?> checkUsername(String username);
-  Future<List<User>> searchUsers({
+  Future<Result<User>> getUserProfile();
+  Future<Result<bool>> updateUserProfile(User user);
+  Future<Result<bool>> updateUsername(String username);
+  Future<Result<bool>> checkUsername(String username);
+  Future<Result<List<User>>> searchUsers({
     required String keyword,
     required int skip,
     required int limit,
   });
-  Future<String?> getPresignedUrl();
-  Future<String?> uploadImageToS3({
+  Future<Result<String>> getPresignedUrl();
+  Future<Result<String>> uploadImageToS3({
     required String uploadUrl,
     required Uint8List image,
   });
@@ -35,21 +38,21 @@ class UserRemoteDataSourceImpl extends UserRemoteDataSource {
   UserRemoteDataSourceImpl(this._remoteData);
 
   @override
-  Future<String?> getPresignedUrl() async {
+  Future<Result<String>> getPresignedUrl() async {
     final Response response = await _remoteData.postRoute(
       ApiEndpoints.presignedUrlS3,
     );
 
     if (response.statusCode == StatusCode.created) {
       final Map<String, dynamic> rawData = response.data;
-      return rawData['presignedUrl'];
+      return Result.success(rawData['presignedUrl']);
     }
 
-    return null;
+    return Result.failure(ServerFailure());
   }
 
   @override
-  Future<String?> uploadImageToS3({
+  Future<Result<String>> uploadImageToS3({
     required String uploadUrl,
     required Uint8List image,
   }) async {
@@ -63,62 +66,70 @@ class UserRemoteDataSourceImpl extends UserRemoteDataSource {
       );
 
       if (response.statusCode == StatusCode.ok) {
-        return uploadUrl.split('?').first;
+        return Result.success(uploadUrl.split('?').first);
       }
 
-      return null;
+      return Result.failure(ServerFailure());
     } catch (error) {
-      return null;
+      return Result.failure(ServerFailure());
     }
   }
 
   @override
-  Future<User?> getUserProfile() async {
+  Future<Result<User>> getUserProfile() async {
     final Response response = await _remoteData.getRoute(ApiEndpoints.users);
 
     if (response.statusCode == StatusCode.ok) {
       final Map<String, dynamic> rawData = response.data;
-      return User.fromMap(rawData);
+      return Result.success(User.fromMap(rawData));
     }
 
-    return null;
+    return Result.failure(response.data['message'].toString().userException);
   }
 
   @override
-  Future<bool> updateUserProfile(User user) async {
+  Future<Result<bool>> updateUserProfile(User user) async {
     final Response response = await _remoteData.putRoute(
       ApiEndpoints.users,
       user.toMap(),
     );
 
-    return response.statusCode == StatusCode.ok;
+    if (response.statusCode == StatusCode.ok) {
+      return Result.success(true);
+    }
+
+    return Result.failure(response.data['message'].toString().userException);
   }
 
   @override
-  Future<bool> updateUsername(String username) async {
+  Future<Result<bool>> updateUsername(String username) async {
     final Response response = await _remoteData.putRoute(
       "${ApiEndpoints.username}/$username",
       {},
     );
 
-    return response.statusCode == StatusCode.ok;
+    if (response.statusCode == StatusCode.ok) {
+      return Result.success(true);
+    }
+
+    return Result.failure(response.data['message'].toString().userException);
   }
 
   @override
-  Future<bool> checkUsername(String username) async {
+  Future<Result<bool>> checkUsername(String username) async {
     final Response response = await _remoteData.getRoute(
       "${ApiEndpoints.username}/$username",
     );
 
     if (response.statusCode == StatusCode.ok) {
-      return response.data['isRegistered'] ?? false;
+      return Result.success(response.data['isRegistered'] ?? false);
     }
 
-    return false;
+    return Result.failure(response.data['message'].toString().userException);
   }
 
   @override
-  Future<List<User>> searchUsers({
+  Future<Result<List<User>>> searchUsers({
     required String keyword,
     required int skip,
     required int limit,
@@ -131,9 +142,11 @@ class UserRemoteDataSourceImpl extends UserRemoteDataSource {
     if (response.statusCode == StatusCode.ok) {
       final List data = response.data['hits'];
 
-      return data.map((user) => User.fromMap(user['document'])).toList();
+      return Result.success(
+        data.map((user) => User.fromMap(user['document'])).toList(),
+      );
     }
 
-    return [];
+    return Result.failure(response.data['message'].toString().userException);
   }
 }
diff --git a/lib/core/api/user/repositories/user_repository.dart b/lib/core/api/user/repositories/user_repository.dart
index ed83040..be819d9 100644
--- a/lib/core/api/user/repositories/user_repository.dart
+++ b/lib/core/api/user/repositories/user_repository.dart
@@ -4,18 +4,19 @@ import 'package:injectable/injectable.dart';
 
 import 'package:waterbus_sdk/core/api/user/datasources/user_remote_datasource.dart';
 import 'package:waterbus_sdk/types/models/user_model.dart';
+import 'package:waterbus_sdk/types/result.dart';
 
 abstract class UserRepository {
-  Future<User?> getUserProfile();
-  Future<User?> updateUserProfile(User user);
-  Future<bool> updateUsername(String username);
-  Future<bool> checkUsername(String username);
-  Future<String?> getPresignedUrl();
-  Future<String?> uploadImageToS3({
+  Future<Result<User>> getUserProfile();
+  Future<Result<bool>> updateUserProfile(User user);
+  Future<Result<bool>> updateUsername(String username);
+  Future<Result<bool>> checkUsername(String username);
+  Future<Result<String>> getPresignedUrl();
+  Future<Result<String>> uploadImageToS3({
     required String uploadUrl,
     required Uint8List image,
   });
-  Future<List<User>> searchUsers({
+  Future<Result<List<User>>> searchUsers({
     required String keyword,
     required int skip,
     required int limit,
@@ -29,70 +30,68 @@ class UserRepositoryImpl extends UserRepository {
   UserRepositoryImpl(this._remoteDataSource);
 
   @override
-  Future<User?> getUserProfile() async {
-    final User? user = await _remoteDataSource.getUserProfile();
+  Future<Result<User>> getUserProfile() async {
+    final Result<User> user = await _remoteDataSource.getUserProfile();
 
     return user;
   }
 
   @override
-  Future<User?> updateUserProfile(User user) async {
-    final bool isUpdateSucceed = await _remoteDataSource.updateUserProfile(
+  Future<Result<bool>> updateUserProfile(User user) async {
+    final Result<bool> result = await _remoteDataSource.updateUserProfile(
       user,
     );
 
-    if (!isUpdateSucceed) return null;
-
-    return user;
+    return result;
   }
 
   @override
-  Future<String?> getPresignedUrl() async {
-    final String? presignedUrl = await _remoteDataSource.getPresignedUrl();
+  Future<Result<String>> getPresignedUrl() async {
+    final Result<String> result = await _remoteDataSource.getPresignedUrl();
 
-    return presignedUrl;
+    return result;
   }
 
   @override
-  Future<String?> uploadImageToS3({
+  Future<Result<String>> uploadImageToS3({
     required String uploadUrl,
     required Uint8List image,
   }) async {
-    final String? urlToImage = await _remoteDataSource.uploadImageToS3(
+    final Result<String> result = await _remoteDataSource.uploadImageToS3(
       uploadUrl: uploadUrl,
       image: image,
     );
 
-    return urlToImage;
+    return result;
   }
 
   @override
-  Future<bool> updateUsername(String username) async {
-    final bool isUpdateSucceed =
+  Future<Result<bool>> updateUsername(String username) async {
+    final Result<bool> result =
         await _remoteDataSource.updateUsername(username);
 
-    return isUpdateSucceed;
+    return result;
   }
 
   @override
-  Future<bool> checkUsername(String username) async {
-    final bool? isRegistered = await _remoteDataSource.checkUsername(username);
+  Future<Result<bool>> checkUsername(String username) async {
+    final Result<bool> result = await _remoteDataSource.checkUsername(username);
 
-    return isRegistered ?? false;
+    return result;
   }
 
   @override
-  Future<List<User>> searchUsers({
+  Future<Result<List<User>>> searchUsers({
     required String keyword,
     required int skip,
     required int limit,
   }) async {
-    final List<User> users = await _remoteDataSource.searchUsers(
+    final Result<List<User>> result = await _remoteDataSource.searchUsers(
       keyword: keyword,
       limit: limit,
       skip: skip,
     );
 
-    return users;
+    return result;
   }
 }
diff --git a/lib/flutter_waterbus_sdk.dart b/lib/flutter_waterbus_sdk.dart
index 003c796..1bc94c2 100644
--- a/lib/flutter_waterbus_sdk.dart
+++ b/lib/flutter_waterbus_sdk.dart
@@ -86,7 +86,7 @@ class WaterbusSdk {
   }
 
   // Meeting
-  Future<Meeting?> createRoom({
+  Future<Result<Meeting>> createRoom({
     required Meeting meeting,
     required String password,
     required int? userId,
@@ -98,7 +98,7 @@ class WaterbusSdk {
     );
   }
 
-  Future<Meeting?> joinRoom({
+  Future<Result<Meeting>> joinRoom({
     required Meeting meeting,
     required String password,
     required int? userId,
@@ -110,7 +110,7 @@ class WaterbusSdk {
     );
   }
 
-  Future<Meeting?> updateRoom({
+  Future<Result<bool>> updateRoom({
     required Meeting meeting,
     required String password,
     required int? userId,
@@ -122,19 +122,22 @@ class WaterbusSdk {
     );
   }
 
-  Future<Meeting?> getRoomInfo({required int code}) async {
+  Future<Result<Meeting>> getRoomInfo({required int code}) async {
     return await _sdk.getRoomInfo(code);
   }
 
-  Future<List<RecordModel>> getRecords({int skip = 0, int limit = 10}) async {
+  Future<Result<List<RecordModel>>> getRecords({
+    int skip = 0,
+    int limit = 10,
+  }) async {
     return await _sdk.getRecords(skip: skip, limit: limit);
   }
 
-  Future<int?> startRecord() async {
+  Future<Result<int>> startRecord() async {
     return await _sdk.startRecord();
   }
 
-  Future<bool> stopRecord() async {
+  Future<Result<bool>> stopRecord() async {
     return await _sdk.stopRecord();
   }
 
@@ -243,38 +246,38 @@ class WaterbusSdk {
   }
 
   // User
-  Future<User?> getProfile() async {
+  Future<Result<User>> getProfile() async {
     return await _sdk.getProfile();
   }
 
-  Future<User?> updateProfile({required User user}) async {
+  Future<Result<bool>> updateProfile({required User user}) async {
     return await _sdk.updateProfile(user: user);
   }
 
-  Future<bool?> updateUsername({
+  Future<Result<bool>> updateUsername({
     required String username,
   }) async {
     return await _sdk.updateUsername(username: username);
   }
 
-  Future<bool> checkUsername({
+  Future<Result<bool>> checkUsername({
     required String username,
   }) async {
     return await _sdk.checkUsername(username: username);
   }
 
-  Future<String?> getPresignedUrl() async {
+  Future<Result<String>> getPresignedUrl() async {
     return await _sdk.getPresignedUrl();
   }
 
-  Future<String?> uploadAvatar({
+  Future<Result<String>> uploadAvatar({
     required Uint8List image,
     required String uploadUrl,
   }) async {
     return await _sdk.uploadAvatar(image: image, uploadUrl: uploadUrl);
   }
 
-  Future<List<User>> searchUsers({
+  Future<Result<List<User>>> searchUsers({
     required String keyword,
     required int skip,
     int limit = 10,
@@ -371,15 +374,15 @@ class WaterbusSdk {
   }
 
   // Auth
-  Future<User?> createToken(AuthPayloadModel payload) async {
+  Future<Result<User>> createToken(AuthPayloadModel payload) async {
     return await _sdk.createToken(payload: payload);
   }
 
-  Future<bool> deleteToken() async {
+  Future<Result<bool>> deleteToken() async {
     return await _sdk.deleteToken();
   }
 
-  Future<bool?> renewToken() async {
+  Future<Result<bool>> renewToken() async {
     return await _sdk.refreshToken();
   }
 
diff --git a/lib/types/error/user_failure.dart b/lib/types/error/user_failure.dart
index d796563..ee8821e 100644
--- a/lib/types/error/user_failure.dart
+++ b/lib/types/error/user_failure.dart
@@ -1,3 +1,5 @@
 part of 'failures.dart';
 
 class UserNotFound extends Failure {}
+
+class UserIsAlreadyUsed extends Failure {}
diff --git a/lib/types/models/exceptions/exceptions.dart b/lib/types/models/exceptions/exceptions.dart
index a6c7648..5de8e66 100644
--- a/lib/types/models/exceptions/exceptions.dart
+++ b/lib/types/models/exceptions/exceptions.dart
@@ -2,3 +2,4 @@ import 'package:waterbus_sdk/types/error/failures.dart';
 
 part "meeting_exceptions.dart";
 part "message_exceptions.dart";
+part "user_exceptions.dart";
diff --git a/lib/types/models/exceptions/user_exceptions.dart b/lib/types/models/exceptions/user_exceptions.dart
new file mode 100644
index 0000000..ac9ae08
--- /dev/null
+++ b/lib/types/models/exceptions/user_exceptions.dart
@@ -0,0 +1,27 @@
+part of 'exceptions.dart';
+
+enum UserException {
+  userNotFound("User not found"),
+  usernameIsAlreadyUsed("Username is already used"),
+  ;
+
+  const UserException(this.message);
+
+  final String message;
+
+  Failure get userFailure => switch (this) {
+        UserException.userNotFound => UserNotFound(),
+        UserException.usernameIsAlreadyUsed => UserIsAlreadyUsed(),
+      };
+}
+
+extension UserExceptionX on String {
+  Failure get userException {
+    final int index = UserException.values
+        .indexWhere((exception) => exception.message == this);
+
+    if (index == -1) return ServerFailure();
+
+    return UserException.values[index].userFailure;
+  }
+}
diff --git a/lib/waterbus_sdk_impl.dart b/lib/waterbus_sdk_impl.dart
index c4edc97..ad3a26c 100644
--- a/lib/waterbus_sdk_impl.dart
+++ b/lib/waterbus_sdk_impl.dart
@@ -17,6 +17,7 @@ import 'package:waterbus_sdk/flutter_waterbus_sdk.dart';
 import 'package:waterbus_sdk/native/picture-in-picture/index.dart';
 import 'package:waterbus_sdk/native/replaykit.dart';
 import 'package:waterbus_sdk/types/enums/draw_action.dart';
+import 'package:waterbus_sdk/types/error/failures.dart';
 import 'package:waterbus_sdk/types/models/create_meeting_params.dart';
 import 'package:waterbus_sdk/types/models/draw_model.dart';
 import 'package:waterbus_sdk/types/models/record_model.dart';
@@ -74,7 +75,7 @@ class SdkCore extends WaterbusSdkInterface {
 
   // Meeting
   @override
-  Future<Meeting?> createRoom({
+  Future<Result<Meeting>> createRoom({
     required Meeting meeting,
     required String password,
     required int? userId,
@@ -89,14 +90,14 @@ class SdkCore extends WaterbusSdkInterface {
   }
 
   @override
-  Future<Meeting?> joinRoom({
+  Future<Result<Meeting>> joinRoom({
     required Meeting meeting,
     required String password,
     required int? userId,
   }) async {
-    if (!_webSocket.isConnected) return null;
+    if (!_webSocket.isConnected) return Result.failure(ServerFailure());
 
-    late final Meeting? room;
+    late final Result<Meeting> room;
 
     if (password.isEmpty) {
       room = await _meetingRepository.joinMeetingWithoutPassword(
@@ -116,19 +117,21 @@ class SdkCore extends WaterbusSdkInterface {
       );
     }
 
-    if (room != null) {
-      final int mParticipantIndex = room.participants.lastIndexWhere(
+    if (room.value != null) {
+      final Meeting meeting = room.value!;
+
+      final int mParticipantIndex = meeting.participants.lastIndexWhere(
         (participant) => participant.isMe,
       );
 
-      if (mParticipantIndex < 0) return null;
+      if (mParticipantIndex < 0) return Result.failure(ServerFailure());
 
       await _joinRoom(
-        roomId: room.code.toString(),
-        participantId: room.participants[mParticipantIndex].id,
+        roomId: meeting.code.toString(),
+        participantId: meeting.participants[mParticipantIndex].id,
       );
 
-      final List<String> targetIds = room.participants
+      final List<String> targetIds = meeting.participants
           .where((participant) => !participant.isMe)
           .map((participant) => participant.id.toString())
           .toList();
@@ -136,11 +139,11 @@ class SdkCore extends WaterbusSdkInterface {
       _subscribe(targetIds);
     }
 
-    return room;
+    return Result.success(meeting);
   }
 
   @override
-  Future<Meeting?> updateRoom({
+  Future<Result<bool>> updateRoom({
     required Meeting meeting,
     required String password,
     required int? userId,
@@ -155,12 +158,12 @@ class SdkCore extends WaterbusSdkInterface {
   }
 
   @override
-  Future<Meeting?> getRoomInfo(int code) async {
+  Future<Result<Meeting>> getRoomInfo(int code) async {
     return await _meetingRepository.getInfoMeeting(code);
   }
 
   @override
-  Future<List<RecordModel>> getRecords({
+  Future<Result<List<RecordModel>>> getRecords({
     required int skip,
     required int limit,
   }) async {
@@ -168,19 +171,19 @@ class SdkCore extends WaterbusSdkInterface {
   }
 
   @override
-  Future<int?> startRecord() async {
+  Future<Result<int>> startRecord() async {
     final String? meetingId = _rtcManager.roomId;
 
-    if (meetingId == null) return null;
+    if (meetingId == null) return Result.failure(ServerFailure());
 
     return await _meetingRepository.startRecord(int.parse(meetingId));
   }
 
   @override
-  Future<bool> stopRecord() async {
+  Future<Result<bool>> stopRecord() async {
     final String? meetingId = _rtcManager.roomId;
 
-    if (meetingId == null) return false;
+    if (meetingId == null) return Result.failure(ServerFailure());
 
     return await _meetingRepository.stopRecord(int.parse(meetingId));
   }
@@ -436,36 +439,36 @@ class SdkCore extends WaterbusSdkInterface {
 
   // User
   @override
-  Future<User?> getProfile() async {
+  Future<Result<User>> getProfile() async {
     return await _userRepository.getUserProfile();
   }
 
   @override
-  Future<User?> updateProfile({required User user}) async {
+  Future<Result<bool>> updateProfile({required User user}) async {
     return await _userRepository.updateUserProfile(user);
   }
 
   @override
-  Future<bool> updateUsername({
+  Future<Result<bool>> updateUsername({
     required String username,
   }) async {
     return await _userRepository.updateUsername(username);
   }
 
   @override
-  Future<bool> checkUsername({
+  Future<Result<bool>> checkUsername({
     required String username,
   }) async {
     return await _userRepository.checkUsername(username);
   }
 
   @override
-  Future<String?> getPresignedUrl() async {
+  Future<Result<String>> getPresignedUrl() async {
     return await _userRepository.getPresignedUrl();
   }
 
   @override
-  Future<String?> uploadAvatar({
+  Future<Result<String>> uploadAvatar({
     required Uint8List image,
     required String uploadUrl,
   }) async {
@@ -476,7 +479,7 @@ class SdkCore extends WaterbusSdkInterface {
   }
 
   @override
-  Future<List<User>> searchUsers({
+  Future<Result<List<User>>> searchUsers({
     required String keyword,
     required int skip,
     required int limit,
@@ -490,10 +493,10 @@ class SdkCore extends WaterbusSdkInterface {
 
   // Auth
   @override
-  Future<User?> createToken({required AuthPayloadModel payload}) async {
-    final User? user = await _authRepository.loginWithSocial(payload);
+  Future<Result<User>> createToken({required AuthPayloadModel payload}) async {
+    final Result<User> user = await _authRepository.loginWithSocial(payload);
 
-    if (user != null) {
+    if (user.isSuccess) {
       _webSocket.establishConnection(forceConnection: true);
     }
 
@@ -501,14 +504,14 @@ class SdkCore extends WaterbusSdkInterface {
   }
 
   @override
-  Future<bool> deleteToken() async {
+  Future<Result<bool>> deleteToken() async {
     _webSocket.disconnection();
 
     return await _authRepository.logOut();
   }
 
   @override
-  Future<bool> refreshToken() async {
+  Future<Result<bool>> refreshToken() async {
     return await _authRepository.refreshToken();
   }
 
diff --git a/lib/waterbus_sdk_interface.dart b/lib/waterbus_sdk_interface.dart
index fc6935a..cda0c23 100644
--- a/lib/waterbus_sdk_interface.dart
+++ b/lib/waterbus_sdk_interface.dart
@@ -10,21 +10,21 @@ abstract class WaterbusSdkInterface {
   Future<void> initializeApp();
 
   // Auth
-  Future<User?> createToken({required AuthPayloadModel payload});
-  Future<bool> deleteToken();
-  Future<bool> refreshToken();
+  Future<Result<User>> createToken({required AuthPayloadModel payload});
+  Future<Result<bool>> deleteToken();
+  Future<Result<bool>> refreshToken();
 
   // User
-  Future<User?> getProfile();
-  Future<User?> updateProfile({required User user});
-  Future<bool> updateUsername({required String username});
-  Future<bool> checkUsername({required String username});
-  Future<String?> getPresignedUrl();
-  Future<String?> uploadAvatar({
+  Future<Result<User>> getProfile();
+  Future<Result<bool>> updateProfile({required User user});
+  Future<Result<bool>> updateUsername({required String username});
+  Future<Result<bool>> checkUsername({required String username});
+  Future<Result<String>> getPresignedUrl();
+  Future<Result<String>> uploadAvatar({
     required Uint8List image,
     required String uploadUrl,
   });
-  Future<List<User>> searchUsers({
+  Future<Result<List<User>>> searchUsers({
     required String keyword,
     required int skip,
     required int limit,
@@ -71,25 +71,28 @@ abstract class WaterbusSdkInterface {
   Future<Result<MessageModel>> deleteMessage({required int messageId});
 
   // Meeting
-  Future<Meeting?> createRoom({
+  Future<Result<Meeting>> createRoom({
     required Meeting meeting,
     required String password,
     required int? userId,
   });
-  Future<Meeting?> updateRoom({
+  Future<Result<bool>> updateRoom({
     required Meeting meeting,
     required String password,
     required int? userId,
   });
-  Future<Meeting?> joinRoom({
+  Future<Result<Meeting>> joinRoom({
     required Meeting meeting,
     required String password,
     required int? userId,
   });
-  Future<Meeting?> getRoomInfo(int code);
-  Future<List<RecordModel>> getRecords({required int skip, required int limit});
-  Future<int?> startRecord();
-  Future<bool> stopRecord();
+  Future<Result<Meeting>> getRoomInfo(int code);
+  Future<Result<List<RecordModel>>> getRecords({
+    required int skip,
+    required int limit,
+  });
+  Future<Result<int>> startRecord();
+  Future<Result<bool>> stopRecord();
   Future<void> leaveRoom();
 
   void toggleRaiseHand();
diff --git a/test/features/auth/data/repositories/auth_repository_imp_test.dart b/test/features/auth/data/repositories/auth_repository_imp_test.dart
index e2e2e05..49780c5 100644
--- a/test/features/auth/data/repositories/auth_repository_imp_test.dart
+++ b/test/features/auth/data/repositories/auth_repository_imp_test.dart
@@ -8,6 +8,7 @@ import 'package:waterbus_sdk/core/api/auth/datasources/auth_local_datasource.dar
 import 'package:waterbus_sdk/core/api/auth/datasources/auth_remote_datasource.dart';
 import 'package:waterbus_sdk/core/api/auth/repositories/auth_repository.dart';
 import 'package:waterbus_sdk/types/index.dart';
+import 'package:waterbus_sdk/types/result.dart';
 import '../../../../constants/sample_file_path.dart';
 import '../../../../fixtures/fixture_reader.dart';
 import 'auth_repository_imp_test.mocks.dart';
@@ -42,16 +43,16 @@ void main() {
       final User user = User.fromMap(userJson);
 
       when(mockAuthRemoteDataSource.signInWithSocial(authParams)).thenAnswer(
-        (realInvocation) => Future.value(user),
+        (realInvocation) => Future.value(Result.success(user)),
       );
 
       // act
-      final User? result = await repository.loginWithSocial(
+      final Result<User> result = await repository.loginWithSocial(
         authParams,
       );
 
       // assert
-      expect(result, user);
+      expect(result.value, user);
 
       verify(repository.loginWithSocial(authParams));
       verifyNever(
@@ -64,14 +65,14 @@ void main() {
     test('log out success', () async {
       // arrange
       when(mockAuthRemoteDataSource.logOut()).thenAnswer(
-        (realInvocation) => Future.value(true),
+        (realInvocation) => Future.value(Result.success(true)),
       );
 
       // act
-      final bool result = await repository.logOut();
+      final Result<bool> result = await repository.logOut();
 
       // assert
-      expect(result, true);
+      expect(result.value, true);
 
       verify(mockAuthRemoteDataSource.logOut());
       verify(mockAuthLocalDataSource.clearToken());
diff --git a/test/features/auth/data/repositories/auth_repository_imp_test.mocks.dart b/test/features/auth/data/repositories/auth_repository_imp_test.mocks.dart
index 977b707..b8c2d89 100644
--- a/test/features/auth/data/repositories/auth_repository_imp_test.mocks.dart
+++ b/test/features/auth/data/repositories/auth_repository_imp_test.mocks.dart
@@ -4,18 +4,19 @@
 
 // ignore_for_file: no_leading_underscores_for_library_prefixes
 
-import 'dart:async' as _i5;
+import 'dart:async' as _i6;
 
 import 'package:mockito/mockito.dart' as _i1;
-import 'package:mockito/src/dummies.dart' as _i3;
+import 'package:mockito/src/dummies.dart' as _i4;
 
-import 'package:waterbus_sdk/types/models/auth_payload_model.dart' as _i7;
-import 'package:waterbus_sdk/types/models/user_model.dart' as _i6;
+import 'package:waterbus_sdk/types/models/auth_payload_model.dart' as _i8;
+import 'package:waterbus_sdk/types/models/user_model.dart' as _i7;
+import 'package:waterbus_sdk/types/result.dart' as _i2;
 
 import 'package:waterbus_sdk/core/api/auth/datasources/auth_local_datasource.dart'
-    as _i2;
+    as _i3;
 import 'package:waterbus_sdk/core/api/auth/datasources/auth_remote_datasource.dart'
-    as _i4;
+    as _i5;
 
 // ignore_for_file: type=lint
 // ignore_for_file: avoid_redundant_argument_values
@@ -30,19 +31,29 @@ import 'package:waterbus_sdk/core/api/auth/datasources/auth_remote_datasource.da
 // ignore_for_file: camel_case_types
 // ignore_for_file: subtype_of_sealed_class
 
+class _FakeResult_0<T> extends _i1.SmartFake implements _i2.Result<T> {
+  _FakeResult_0(
+    Object parent,
+    Invocation parentInvocation,
+  ) : super(
+          parent,
+          parentInvocation,
+        );
+}
+
 /// A class which mocks [AuthLocalDataSource].
 ///
 /// See the documentation for Mockito's code generation for more information.
 class MockAuthLocalDataSource extends _i1.Mock
-    implements _i2.AuthLocalDataSource {
+    implements _i3.AuthLocalDataSource {
   @override
   String get accessToken => (super.noSuchMethod(
         Invocation.getter(#accessToken),
-        returnValue: _i3.dummyValue<String>(
+        returnValue: _i4.dummyValue<String>(
           this,
           Invocation.getter(#accessToken),
         ),
-        returnValueForMissingStub: _i3.dummyValue<String>(
+        returnValueForMissingStub: _i4.dummyValue<String>(
           this,
           Invocation.getter(#accessToken),
         ),
@@ -51,11 +62,11 @@ class MockAuthLocalDataSource extends _i1.Mock
   @override
   String get refreshToken => (super.noSuchMethod(
         Invocation.getter(#refreshToken),
-        returnValue: _i3.dummyValue<String>(
+        returnValue: _i4.dummyValue<String>(
           this,
           Invocation.getter(#refreshToken),
         ),
-        returnValueForMissingStub: _i3.dummyValue<String>(
+        returnValueForMissingStub: _i4.dummyValue<String>(
           this,
           Invocation.getter(#refreshToken),
         ),
@@ -92,36 +103,64 @@ class MockAuthLocalDataSource extends _i1.Mock
 ///
 /// See the documentation for Mockito's code generation for more information.
 class MockAuthRemoteDataSource extends _i1.Mock
-    implements _i4.AuthRemoteDataSource {
+    implements _i5.AuthRemoteDataSource {
   @override
-  _i5.Future<(String?, String?)> refreshToken() => (super.noSuchMethod(
+  _i6.Future<(String?, String?)> refreshToken() => (super.noSuchMethod(
         Invocation.method(
           #refreshToken,
           [],
         ),
-        returnValue: _i5.Future<(String?, String?)>.value((null, null)),
+        returnValue: _i6.Future<(String?, String?)>.value((null, null)),
         returnValueForMissingStub:
-            _i5.Future<(String?, String?)>.value((null, null)),
-      ) as _i5.Future<(String?, String?)>);
+            _i6.Future<(String?, String?)>.value((null, null)),
+      ) as _i6.Future<(String?, String?)>);
 
   @override
-  _i5.Future<_i6.User?> signInWithSocial(_i7.AuthPayloadModel? authPayload) =>
+  _i6.Future<_i2.Result<_i7.User>> signInWithSocial(
+          _i8.AuthPayloadModel? authPayload) =>
       (super.noSuchMethod(
         Invocation.method(
           #signInWithSocial,
           [authPayload],
         ),
-        returnValue: _i5.Future<_i6.User?>.value(),
-        returnValueForMissingStub: _i5.Future<_i6.User?>.value(),
-      ) as _i5.Future<_i6.User?>);
+        returnValue:
+            _i6.Future<_i2.Result<_i7.User>>.value(_FakeResult_0<_i7.User>(
+          this,
+          Invocation.method(
+            #signInWithSocial,
+            [authPayload],
+          ),
+        )),
+        returnValueForMissingStub:
+            _i6.Future<_i2.Result<_i7.User>>.value(_FakeResult_0<_i7.User>(
+          this,
+          Invocation.method(
+            #signInWithSocial,
+            [authPayload],
+          ),
+        )),
+      ) as _i6.Future<_i2.Result<_i7.User>>);
 
   @override
-  _i5.Future<bool> logOut() => (super.noSuchMethod(
+  _i6.Future<_i2.Result<bool>> logOut() => (super.noSuchMethod(
         Invocation.method(
           #logOut,
           [],
         ),
-        returnValue: _i5.Future<bool>.value(false),
-        returnValueForMissingStub: _i5.Future<bool>.value(false),
-      ) as _i5.Future<bool>);
+        returnValue: _i6.Future<_i2.Result<bool>>.value(_FakeResult_0<bool>(
+          this,
+          Invocation.method(
+            #logOut,
+            [],
+          ),
+        )),
+        returnValueForMissingStub:
+            _i6.Future<_i2.Result<bool>>.value(_FakeResult_0<bool>(
+          this,
+          Invocation.method(
+            #logOut,
+            [],
+          ),
+        )),
+      ) as _i6.Future<_i2.Result<bool>>);
 }
diff --git a/test/features/profile/data/repositories/user_repository_impl_test.dart b/test/features/profile/data/repositories/user_repository_impl_test.dart
index de0ac9f..f10b08c 100644
--- a/test/features/profile/data/repositories/user_repository_impl_test.dart
+++ b/test/features/profile/data/repositories/user_repository_impl_test.dart
@@ -6,7 +6,9 @@ import 'package:mockito/mockito.dart';
 
 import 'package:waterbus_sdk/core/api/user/datasources/user_remote_datasource.dart';
 import 'package:waterbus_sdk/core/api/user/repositories/user_repository.dart';
+import 'package:waterbus_sdk/types/error/failures.dart';
 import 'package:waterbus_sdk/types/models/user_model.dart';
+import 'package:waterbus_sdk/types/result.dart';
 import 'user_repository_impl_test.mocks.dart';
 
 @GenerateNiceMocks([MockSpec<UserRemoteDataSource>()])
@@ -24,27 +26,29 @@ void main() {
   group('getUserProfile', () {
     test('should return user from remote data source', () async {
       // Arrange
-      when(mockDataSource.getUserProfile()).thenAnswer((_) async => testUser);
+      when(mockDataSource.getUserProfile())
+          .thenAnswer((_) async => Result.success(testUser));
 
       // Act
       final result = await repository.getUserProfile();
 
       // Assert
-      expect(result, testUser);
+      expect(result.value, testUser);
       verify(mockDataSource.getUserProfile());
       verifyNoMoreInteractions(mockDataSource);
     });
 
     test('should return a failure from remote data source', () async {
       // Arrange
-      when(mockDataSource.getUserProfile())
-          .thenAnswer((realInvocation) async => null);
+      when(mockDataSource.getUserProfile()).thenAnswer(
+        (realInvocation) async => Result.failure(ServerFailure()),
+      );
 
       // Act
       final result = await repository.getUserProfile();
 
       // Assert
-      expect(result, null);
+      expect(result.error, ServerFailure());
       verify(mockDataSource.getUserProfile());
       verifyNoMoreInteractions(mockDataSource);
     });
@@ -54,13 +58,13 @@ void main() {
     test('should return updated user from remote data source', () async {
       // Arrange
       when(mockDataSource.updateUserProfile(testUser))
-          .thenAnswer((_) async => true);
+          .thenAnswer((_) async => Result.success(true));
 
       // Act
       final result = await repository.updateUserProfile(testUser);
 
       // Assert
-      expect(result, testUser);
+      expect(result.value, true);
       verify(mockDataSource.updateUserProfile(testUser));
       verifyNoMoreInteractions(mockDataSource);
     });
@@ -68,13 +72,13 @@ void main() {
     test('should return a failure from remote data source', () async {
       // Arrange
       when(mockDataSource.updateUserProfile(testUser))
-          .thenAnswer((_) async => false);
+          .thenAnswer((_) async => Result.failure(ServerFailure()));
 
       // Act
       final result = await repository.updateUserProfile(testUser);
 
       // Assert
-      expect(result, null);
+      expect(result.error, ServerFailure());
       verify(mockDataSource.updateUserProfile(testUser));
       verifyNoMoreInteractions(mockDataSource);
     });
@@ -84,13 +88,13 @@ void main() {
     test('should return true from remote data source', () async {
       // Arrange
       when(mockDataSource.updateUsername(testUser.userName))
-          .thenAnswer((_) async => true);
+          .thenAnswer((_) async => Result.success(true));
 
       // Act
       final result = await repository.updateUsername(testUser.userName);
 
       // Assert
-      expect(result, true);
+      expect(result.value, true);
       verify(mockDataSource.updateUsername(testUser.userName));
       verifyNoMoreInteractions(mockDataSource);
     });
@@ -98,13 +102,13 @@ void main() {
     test('should return a failure from remote data source', () async {
       // Arrange
       when(mockDataSource.updateUsername(testUser.userName))
-          .thenAnswer((_) async => false);
+          .thenAnswer((_) async => Result.failure(ServerFailure()));
 
       // Act
       final result = await repository.updateUsername(testUser.userName);
 
       // Assert
-      expect(result, false);
+      expect(result.error, ServerFailure());
       verify(mockDataSource.updateUsername(testUser.userName));
       verifyNoMoreInteractions(mockDataSource);
     });
@@ -114,13 +118,13 @@ void main() {
     test('should return true from remote data source', () async {
       // Arrange
       when(mockDataSource.checkUsername(testUser.userName))
-          .thenAnswer((_) async => true);
+          .thenAnswer((_) async => Result.success(true));
 
       // Act
       final result = await repository.checkUsername(testUser.userName);
 
       // Assert
-      expect(result, true);
+      expect(result.value, true);
       verify(mockDataSource.checkUsername(testUser.userName));
       verifyNoMoreInteractions(mockDataSource);
     });
@@ -128,13 +132,13 @@ void main() {
     test('should return false from remote data source', () async {
       // Arrange
       when(mockDataSource.checkUsername(testUser.userName))
-          .thenAnswer((_) async => false);
+          .thenAnswer((_) async => Result.failure(ServerFailure()));
 
       // Act
       final result = await repository.checkUsername(testUser.userName);
 
       // Assert
-      expect(result, false);
+      expect(result.error, ServerFailure());
       verify(mockDataSource.checkUsername(testUser.userName));
       verifyNoMoreInteractions(mockDataSource);
     });
@@ -142,13 +146,13 @@ void main() {
     test('should return null from remote data source', () async {
       // Arrange
       when(mockDataSource.checkUsername(testUser.userName))
-          .thenAnswer((_) async => null);
+          .thenAnswer((_) async => Result.failure(ServerFailure()));
 
       // Act
       final result = await repository.checkUsername(testUser.userName);
 
       // Assert
-      expect(result, false);
+      expect(result.error, ServerFailure());
       verify(mockDataSource.checkUsername(testUser.userName));
       verifyNoMoreInteractions(mockDataSource);
     });
@@ -158,13 +162,14 @@ void main() {
     test('should return presigned URL from remote data source', () async {
       // Arrange
       const testUrl = 'https://example.com/presigned-url';
-      when(mockDataSource.getPresignedUrl()).thenAnswer((_) async => testUrl);
+      when(mockDataSource.getPresignedUrl())
+          .thenAnswer((_) async => Result.success(testUrl));
 
       // Act
       final result = await repository.getPresignedUrl();
 
       // Assert
-      expect(result, testUrl);
+      expect(result.value, testUrl);
       verify(mockDataSource.getPresignedUrl());
       verifyNoMoreInteractions(mockDataSource);
     });
@@ -172,14 +177,14 @@ void main() {
     test('should return a failure from remote data source', () async {
       // Arrange
       when(mockDataSource.getPresignedUrl()).thenAnswer(
-        (realInvocation) async => null,
+        (realInvocation) async => Result.failure(ServerFailure()),
       );
 
       // Act
       final result = await repository.getPresignedUrl();
 
       // Assert
-      expect(result, null);
+      expect(result.error, ServerFailure());
       verify(mockDataSource.getPresignedUrl());
       verifyNoMoreInteractions(mockDataSource);
     });
@@ -197,7 +202,7 @@ void main() {
           uploadUrl: anyNamed('uploadUrl'),
           image: anyNamed('image'),
         ),
-      ).thenAnswer((_) async => testImageUrl);
+      ).thenAnswer((_) async => Result.success(testImageUrl));
 
       // Act
       final result = await repository.uploadImageToS3(
@@ -206,7 +211,7 @@ void main() {
       );
 
       // Assert
-      expect(result, testImageUrl);
+      expect(result.value, testImageUrl);
       verify(
         mockDataSource.uploadImageToS3(
           uploadUrl: testUploadUrl,
@@ -223,7 +228,7 @@ void main() {
           uploadUrl: anyNamed('uploadUrl'),
           image: anyNamed('image'),
         ),
-      ).thenAnswer((_) async => null);
+      ).thenAnswer((_) async => Result.failure(ServerFailure()));
 
       // Act
       final result = await repository.uploadImageToS3(
@@ -232,7 +237,7 @@ void main() {
       );
 
       // Assert
-      expect(result, null);
+      expect(result.error, ServerFailure());
       verify(
         mockDataSource.uploadImageToS3(
           uploadUrl: testUploadUrl,
diff --git a/test/features/profile/data/repositories/user_repository_impl_test.mocks.dart b/test/features/profile/data/repositories/user_repository_impl_test.mocks.dart
index 0fa0db5..cfb0acf 100644
--- a/test/features/profile/data/repositories/user_repository_impl_test.mocks.dart
+++ b/test/features/profile/data/repositories/user_repository_impl_test.mocks.dart
@@ -4,15 +4,16 @@
 
 // ignore_for_file: no_leading_underscores_for_library_prefixes
 
-import 'dart:async' as _i3;
-import 'dart:typed_data' as _i5;
+import 'dart:async' as _i4;
+import 'dart:typed_data' as _i6;
 
 import 'package:mockito/mockito.dart' as _i1;
 
-import 'package:waterbus_sdk/types/models/user_model.dart' as _i4;
+import 'package:waterbus_sdk/types/models/user_model.dart' as _i5;
+import 'package:waterbus_sdk/types/result.dart' as _i2;
 
 import 'package:waterbus_sdk/core/api/user/datasources/user_remote_datasource.dart'
-    as _i2;
+    as _i3;
 
 // ignore_for_file: type=lint
 // ignore_for_file: avoid_redundant_argument_values
@@ -27,53 +28,119 @@ import 'package:waterbus_sdk/core/api/user/datasources/user_remote_datasource.da
 // ignore_for_file: camel_case_types
 // ignore_for_file: subtype_of_sealed_class
 
+class _FakeResult_0<T> extends _i1.SmartFake implements _i2.Result<T> {
+  _FakeResult_0(
+    Object parent,
+    Invocation parentInvocation,
+  ) : super(
+          parent,
+          parentInvocation,
+        );
+}
+
 /// A class which mocks [UserRemoteDataSource].
 ///
 /// See the documentation for Mockito's code generation for more information.
 class MockUserRemoteDataSource extends _i1.Mock
-    implements _i2.UserRemoteDataSource {
+    implements _i3.UserRemoteDataSource {
   @override
-  _i3.Future<_i4.User?> getUserProfile() => (super.noSuchMethod(
+  _i4.Future<_i2.Result<_i5.User>> getUserProfile() => (super.noSuchMethod(
         Invocation.method(
           #getUserProfile,
           [],
         ),
-        returnValue: _i3.Future<_i4.User?>.value(),
-        returnValueForMissingStub: _i3.Future<_i4.User?>.value(),
-      ) as _i3.Future<_i4.User?>);
+        returnValue:
+            _i4.Future<_i2.Result<_i5.User>>.value(_FakeResult_0<_i5.User>(
+          this,
+          Invocation.method(
+            #getUserProfile,
+            [],
+          ),
+        )),
+        returnValueForMissingStub:
+            _i4.Future<_i2.Result<_i5.User>>.value(_FakeResult_0<_i5.User>(
+          this,
+          Invocation.method(
+            #getUserProfile,
+            [],
+          ),
+        )),
+      ) as _i4.Future<_i2.Result<_i5.User>>);
 
   @override
-  _i3.Future<bool> updateUserProfile(_i4.User? user) => (super.noSuchMethod(
+  _i4.Future<_i2.Result<bool>> updateUserProfile(_i5.User? user) =>
+      (super.noSuchMethod(
         Invocation.method(
           #updateUserProfile,
           [user],
         ),
-        returnValue: _i3.Future<bool>.value(false),
-        returnValueForMissingStub: _i3.Future<bool>.value(false),
-      ) as _i3.Future<bool>);
+        returnValue: _i4.Future<_i2.Result<bool>>.value(_FakeResult_0<bool>(
+          this,
+          Invocation.method(
+            #updateUserProfile,
+            [user],
+          ),
+        )),
+        returnValueForMissingStub:
+            _i4.Future<_i2.Result<bool>>.value(_FakeResult_0<bool>(
+          this,
+          Invocation.method(
+            #updateUserProfile,
+            [user],
+          ),
+        )),
+      ) as _i4.Future<_i2.Result<bool>>);
 
   @override
-  _i3.Future<bool> updateUsername(String? username) => (super.noSuchMethod(
+  _i4.Future<_i2.Result<bool>> updateUsername(String? username) =>
+      (super.noSuchMethod(
         Invocation.method(
           #updateUsername,
           [username],
         ),
-        returnValue: _i3.Future<bool>.value(false),
-        returnValueForMissingStub: _i3.Future<bool>.value(false),
-      ) as _i3.Future<bool>);
+        returnValue: _i4.Future<_i2.Result<bool>>.value(_FakeResult_0<bool>(
+          this,
+          Invocation.method(
+            #updateUsername,
+            [username],
+          ),
+        )),
+        returnValueForMissingStub:
+            _i4.Future<_i2.Result<bool>>.value(_FakeResult_0<bool>(
+          this,
+          Invocation.method(
+            #updateUsername,
+            [username],
+          ),
+        )),
+      ) as _i4.Future<_i2.Result<bool>>);
 
   @override
-  _i3.Future<bool?> checkUsername(String? username) => (super.noSuchMethod(
+  _i4.Future<_i2.Result<bool>> checkUsername(String? username) =>
+      (super.noSuchMethod(
         Invocation.method(
           #checkUsername,
           [username],
         ),
-        returnValue: _i3.Future<bool?>.value(),
-        returnValueForMissingStub: _i3.Future<bool?>.value(),
-      ) as _i3.Future<bool?>);
+        returnValue: _i4.Future<_i2.Result<bool>>.value(_FakeResult_0<bool>(
+          this,
+          Invocation.method(
+            #checkUsername,
+            [username],
+          ),
+        )),
+        returnValueForMissingStub:
+            _i4.Future<_i2.Result<bool>>.value(_FakeResult_0<bool>(
+          this,
+          Invocation.method(
+            #checkUsername,
+            [username],
+          ),
+        )),
+      ) as _i4.Future<_i2.Result<bool>>);
 
   @override
-  _i3.Future<List<_i4.User>> searchUsers({
+  _i4.Future<_i2.Result<List<_i5.User>>> searchUsers({
     required String? keyword,
     required int? skip,
     required int? limit,
@@ -88,25 +155,61 @@ class MockUserRemoteDataSource extends _i1.Mock
             #limit: limit,
           },
         ),
-        returnValue: _i3.Future<List<_i4.User>>.value(<_i4.User>[]),
-        returnValueForMissingStub:
-            _i3.Future<List<_i4.User>>.value(<_i4.User>[]),
-      ) as _i3.Future<List<_i4.User>>);
+        returnValue: _i4.Future<_i2.Result<List<_i5.User>>>.value(
+            _FakeResult_0<List<_i5.User>>(
+          this,
+          Invocation.method(
+            #searchUsers,
+            [],
+            {
+              #keyword: keyword,
+              #skip: skip,
+              #limit: limit,
+            },
+          ),
+        )),
+        returnValueForMissingStub: _i4.Future<_i2.Result<List<_i5.User>>>.value(
+            _FakeResult_0<List<_i5.User>>(
+          this,
+          Invocation.method(
+            #searchUsers,
+            [],
+            {
+              #keyword: keyword,
+              #skip: skip,
+              #limit: limit,
+            },
+          ),
+        )),
+      ) as _i4.Future<_i2.Result<List<_i5.User>>>);
 
   @override
-  _i3.Future<String?> getPresignedUrl() => (super.noSuchMethod(
+  _i4.Future<_i2.Result<String>> getPresignedUrl() => (super.noSuchMethod(
         Invocation.method(
           #getPresignedUrl,
           [],
         ),
-        returnValue: _i3.Future<String?>.value(),
-        returnValueForMissingStub: _i3.Future<String?>.value(),
-      ) as _i3.Future<String?>);
+        returnValue: _i4.Future<_i2.Result<String>>.value(_FakeResult_0<String>(
+          this,
+          Invocation.method(
+            #getPresignedUrl,
+            [],
+          ),
+        )),
+        returnValueForMissingStub:
+            _i4.Future<_i2.Result<String>>.value(_FakeResult_0<String>(
+          this,
+          Invocation.method(
+            #getPresignedUrl,
+            [],
+          ),
+        )),
+      ) as _i4.Future<_i2.Result<String>>);
 
   @override
-  _i3.Future<String?> uploadImageToS3({
+  _i4.Future<_i2.Result<String>> uploadImageToS3({
     required String? uploadUrl,
-    required _i5.Uint8List? image,
+    required _i6.Uint8List? image,
   }) =>
       (super.noSuchMethod(
         Invocation.method(
@@ -117,7 +220,28 @@ class MockUserRemoteDataSource extends _i1.Mock
             #image: image,
           },
         ),
-        returnValue: _i3.Future<String?>.value(),
-        returnValueForMissingStub: _i3.Future<String?>.value(),
-      ) as _i3.Future<String?>);
+        returnValue: _i4.Future<_i2.Result<String>>.value(_FakeResult_0<String>(
+          this,
+          Invocation.method(
+            #uploadImageToS3,
+            [],
+            {
+              #uploadUrl: uploadUrl,
+              #image: image,
+            },
+          ),
+        )),
+        returnValueForMissingStub:
+            _i4.Future<_i2.Result<String>>.value(_FakeResult_0<String>(
+          this,
+          Invocation.method(
+            #uploadImageToS3,
+            [],
+            {
+              #uploadUrl: uploadUrl,
+              #image: image,
+            },
+          ),
+        )),
+      ) as _i4.Future<_i2.Result<String>>);
 }