diff --git a/frontend/src/components/S3BackupConfigDrawer.tsx b/frontend/src/components/S3BackupConfigDrawer.tsx
index daa468f..d11e3e1 100644
--- a/frontend/src/components/S3BackupConfigDrawer.tsx
+++ b/frontend/src/components/S3BackupConfigDrawer.tsx
@@ -1,6 +1,7 @@
 import { useState, useEffect } from "react";
 import { useMutation, useQueryClient } from "@tanstack/react-query";
 import { Cloud, TestTube } from "lucide-react";
+import { toast } from "sonner";
 import { apiClient } from "../lib/api";
 import { Button } from "./ui/button";
 import { Input } from "./ui/input";
@@ -55,9 +56,12 @@ export default function S3BackupConfigDrawer({
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ["backupSettings"] });
       setOpen(false);
+      toast.success("S3 backup configuration saved successfully");
     },
-    onError: (error) => {
+    onError: (error: any) => {
       console.error("Failed to update S3 backup configuration:", error);
+      const message = error?.response?.data?.detail || "Failed to save S3 configuration. Please check your settings and try again.";
+      toast.error(message);
     },
   });
 
@@ -69,9 +73,12 @@ export default function S3BackupConfigDrawer({
       }),
     onSuccess: () => {
       console.log("S3 connection test successful");
+      toast.success("S3 connection test successful! Your configuration is working correctly.");
     },
-    onError: (error) => {
+    onError: (error: any) => {
       console.error("Failed to test S3 connection:", error);
+      const message = error?.response?.data?.detail || "S3 connection test failed. Please verify your credentials and settings.";
+      toast.error(message);
     },
   });
 
@@ -245,4 +252,4 @@ export default function S3BackupConfigDrawer({
       </DrawerContent>
     </Drawer>
   );
-}
\ No newline at end of file
+}
diff --git a/frontend/src/routes/__root.tsx b/frontend/src/routes/__root.tsx
index 63a90fa..f26821e 100644
--- a/frontend/src/routes/__root.tsx
+++ b/frontend/src/routes/__root.tsx
@@ -5,6 +5,7 @@ import { PWAInstallPrompt, PWAUpdatePrompt } from "../components/PWAPrompts";
 import { usePWA } from "../hooks/usePWA";
 import { useVersionCheck } from "../hooks/useVersionCheck";
 import { SidebarInset, SidebarProvider } from "../components/ui/sidebar";
+import { Toaster } from "../components/ui/sonner";
 
 function RootLayout() {
   const { updateAvailable, updateSW, forceReload } = usePWA();
@@ -48,6 +49,9 @@ function RootLayout() {
         updateAvailable={updateAvailable}
         onUpdate={handlePWAUpdate}
       />
+
+      {/* Toast Notifications */}
+      <Toaster />
     </SidebarProvider>
   );
 }
diff --git a/leggen/commands/server.py b/leggen/commands/server.py
index 211d3cb..cc8f0d6 100644
--- a/leggen/commands/server.py
+++ b/leggen/commands/server.py
@@ -7,7 +7,7 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from loguru import logger
 
-from leggen.api.routes import accounts, banks, backup, notifications, sync, transactions
+from leggen.api.routes import accounts, backup, banks, notifications, sync, transactions
 from leggen.background.scheduler import scheduler
 from leggen.utils.config import config
 from leggen.utils.paths import path_manager
diff --git a/leggen/services/backup_service.py b/leggen/services/backup_service.py
index 62c4134..09b2f6d 100644
--- a/leggen/services/backup_service.py
+++ b/leggen/services/backup_service.py
@@ -38,35 +38,40 @@ class BackupService:
             s3_kwargs["endpoint_url"] = current_config.endpoint_url
 
         if current_config.path_style:
-            s3_kwargs["config"] = boto3.client("s3").meta.config
-            s3_kwargs["config"].s3 = {"addressing_style": "path"}
+            from botocore.config import Config
+
+            s3_kwargs["config"] = Config(s3={"addressing_style": "path"})
 
         return session.client("s3", **s3_kwargs)
 
     async def test_connection(self, config: S3BackupConfig) -> bool:
         """Test S3 connection with provided configuration.
-        
+
         Args:
             config: S3 configuration to test
-            
+
         Returns:
             True if connection successful, False otherwise
         """
         try:
             s3_client = self._get_s3_client(config)
-            
+
             # Try to list objects in the bucket (limited to 1 to minimize cost)
             s3_client.list_objects_v2(Bucket=config.bucket_name, MaxKeys=1)
-            
-            logger.info(f"S3 connection test successful for bucket: {config.bucket_name}")
+
+            logger.info(
+                f"S3 connection test successful for bucket: {config.bucket_name}"
+            )
             return True
-            
+
         except NoCredentialsError:
             logger.error("S3 credentials not found or invalid")
             return False
         except ClientError as e:
             error_code = e.response["Error"]["Code"]
-            logger.error(f"S3 connection test failed: {error_code} - {e.response['Error']['Message']}")
+            logger.error(
+                f"S3 connection test failed: {error_code} - {e.response['Error']['Message']}"
+            )
             return False
         except Exception as e:
             logger.error(f"Unexpected error during S3 connection test: {str(e)}")
@@ -74,10 +79,10 @@ class BackupService:
 
     async def backup_database(self, database_path: Path) -> bool:
         """Backup database file to S3.
-        
+
         Args:
             database_path: Path to the SQLite database file
-            
+
         Returns:
             True if backup successful, False otherwise
         """
@@ -91,29 +96,27 @@ class BackupService:
 
         try:
             s3_client = self._get_s3_client()
-            
+
             # Generate backup filename with timestamp
             timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
             backup_key = f"leggen_backups/database_backup_{timestamp}.db"
-            
+
             # Upload database file
             logger.info(f"Starting database backup to S3: {backup_key}")
             s3_client.upload_file(
-                str(database_path),
-                self.s3_config.bucket_name,
-                backup_key
+                str(database_path), self.s3_config.bucket_name, backup_key
             )
-            
+
             logger.info(f"Database backup completed successfully: {backup_key}")
             return True
-            
+
         except Exception as e:
             logger.error(f"Database backup failed: {str(e)}")
             return False
 
     async def list_backups(self) -> list[dict]:
         """List available backups in S3.
-        
+
         Returns:
             List of backup metadata dictionaries
         """
@@ -123,37 +126,38 @@ class BackupService:
 
         try:
             s3_client = self._get_s3_client()
-            
+
             # List objects with backup prefix
             response = s3_client.list_objects_v2(
-                Bucket=self.s3_config.bucket_name,
-                Prefix="leggen_backups/"
+                Bucket=self.s3_config.bucket_name, Prefix="leggen_backups/"
             )
-            
+
             backups = []
             for obj in response.get("Contents", []):
-                backups.append({
-                    "key": obj["Key"],
-                    "last_modified": obj["LastModified"].isoformat(),
-                    "size": obj["Size"],
-                })
-            
+                backups.append(
+                    {
+                        "key": obj["Key"],
+                        "last_modified": obj["LastModified"].isoformat(),
+                        "size": obj["Size"],
+                    }
+                )
+
             # Sort by last modified (newest first)
             backups.sort(key=lambda x: x["last_modified"], reverse=True)
-            
+
             return backups
-            
+
         except Exception as e:
             logger.error(f"Failed to list backups: {str(e)}")
             return []
 
     async def restore_database(self, backup_key: str, restore_path: Path) -> bool:
         """Restore database from S3 backup.
-        
+
         Args:
             backup_key: S3 key of the backup to restore
             restore_path: Path where to restore the database
-            
+
         Returns:
             True if restore successful, False otherwise
         """
@@ -163,28 +167,26 @@ class BackupService:
 
         try:
             s3_client = self._get_s3_client()
-            
+
             # Download backup file
             logger.info(f"Starting database restore from S3: {backup_key}")
-            
+
             # Create parent directory if it doesn't exist
             restore_path.parent.mkdir(parents=True, exist_ok=True)
-            
+
             # Download to temporary file first, then move to final location
             with tempfile.NamedTemporaryFile(delete=False) as temp_file:
                 s3_client.download_file(
-                    self.s3_config.bucket_name,
-                    backup_key,
-                    temp_file.name
+                    self.s3_config.bucket_name, backup_key, temp_file.name
                 )
-                
+
                 # Move temp file to final location
                 temp_path = Path(temp_file.name)
                 temp_path.replace(restore_path)
-            
+
             logger.info(f"Database restore completed successfully: {restore_path}")
             return True
-            
+
         except Exception as e:
             logger.error(f"Database restore failed: {str(e)}")
-            return False
\ No newline at end of file
+            return False
diff --git a/pyproject.toml b/pyproject.toml
index 3edfbd2..4986af5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -89,5 +89,5 @@ markers = [
 ]
 
 [[tool.mypy.overrides]]
-module = ["apscheduler.*", "discord_webhook.*"]
+module = ["apscheduler.*", "discord_webhook.*", "botocore.*", "boto3.*"]
 ignore_missing_imports = true
diff --git a/tests/unit/test_api_backup.py b/tests/unit/test_api_backup.py
index f7205ab..52f077d 100644
--- a/tests/unit/test_api_backup.py
+++ b/tests/unit/test_api_backup.py
@@ -1,12 +1,9 @@
 """Tests for backup API endpoints."""
 
-from unittest.mock import AsyncMock, patch
+from unittest.mock import patch
 
 import pytest
 
-from leggen.api.models.backup import BackupSettings, S3Config
-from leggen.models.config import S3BackupConfig
-
 
 @pytest.mark.api
 class TestBackupAPI:
@@ -16,10 +13,10 @@ class TestBackupAPI:
         """Test getting backup settings with no configuration."""
         # Mock empty backup config by updating the config dict
         mock_config._config["backup"] = {}
-        
+
         with patch("leggen.utils.config.config", mock_config):
             response = api_client.get("/api/v1/backup/settings")
-        
+
         assert response.status_code == 200
         data = response.json()
         assert data["success"] is True
@@ -39,15 +36,15 @@ class TestBackupAPI:
                 "enabled": True,
             }
         }
-        
+
         with patch("leggen.utils.config.config", mock_config):
             response = api_client.get("/api/v1/backup/settings")
-        
+
         assert response.status_code == 200
         data = response.json()
         assert data["success"] is True
         assert data["data"]["s3"] is not None
-        
+
         s3_config = data["data"]["s3"]
         assert s3_config["access_key_id"] == "***"  # Masked
         assert s3_config["secret_access_key"] == "***"  # Masked
@@ -56,11 +53,13 @@ class TestBackupAPI:
         assert s3_config["enabled"] is True
 
     @patch("leggen.services.backup_service.BackupService.test_connection")
-    def test_update_backup_settings_success(self, mock_test_connection, api_client, mock_config):
+    def test_update_backup_settings_success(
+        self, mock_test_connection, api_client, mock_config
+    ):
         """Test successful backup settings update."""
         mock_test_connection.return_value = True
         mock_config._config["backup"] = {}
-        
+
         request_data = {
             "s3": {
                 "access_key_id": "AKIATEST123",
@@ -72,24 +71,26 @@ class TestBackupAPI:
                 "enabled": True,
             }
         }
-        
+
         with patch("leggen.utils.config.config", mock_config):
             response = api_client.put("/api/v1/backup/settings", json=request_data)
-        
+
         assert response.status_code == 200
         data = response.json()
         assert data["success"] is True
         assert data["data"]["updated"] is True
-        
+
         # Verify connection test was called
         mock_test_connection.assert_called_once()
 
     @patch("leggen.services.backup_service.BackupService.test_connection")
-    def test_update_backup_settings_connection_failure(self, mock_test_connection, api_client, mock_config):
+    def test_update_backup_settings_connection_failure(
+        self, mock_test_connection, api_client, mock_config
+    ):
         """Test backup settings update with connection test failure."""
         mock_test_connection.return_value = False
         mock_config._config["backup"] = {}
-        
+
         request_data = {
             "s3": {
                 "access_key_id": "AKIATEST123",
@@ -101,10 +102,10 @@ class TestBackupAPI:
                 "enabled": True,
             }
         }
-        
+
         with patch("leggen.utils.config.config", mock_config):
             response = api_client.put("/api/v1/backup/settings", json=request_data)
-        
+
         assert response.status_code == 400
         data = response.json()
         assert "S3 connection test failed" in data["detail"]
@@ -113,7 +114,7 @@ class TestBackupAPI:
     def test_test_backup_connection_success(self, mock_test_connection, api_client):
         """Test successful backup connection test."""
         mock_test_connection.return_value = True
-        
+
         request_data = {
             "service": "s3",
             "config": {
@@ -124,16 +125,16 @@ class TestBackupAPI:
                 "endpoint_url": None,
                 "path_style": False,
                 "enabled": True,
-            }
+            },
         }
-        
+
         response = api_client.post("/api/v1/backup/test", json=request_data)
-        
+
         assert response.status_code == 200
         data = response.json()
         assert data["success"] is True
         assert data["data"]["connected"] is True
-        
+
         # Verify connection test was called
         mock_test_connection.assert_called_once()
 
@@ -141,7 +142,7 @@ class TestBackupAPI:
     def test_test_backup_connection_failure(self, mock_test_connection, api_client):
         """Test failed backup connection test."""
         mock_test_connection.return_value = False
-        
+
         request_data = {
             "service": "s3",
             "config": {
@@ -152,11 +153,11 @@ class TestBackupAPI:
                 "endpoint_url": None,
                 "path_style": False,
                 "enabled": True,
-            }
+            },
         }
-        
+
         response = api_client.post("/api/v1/backup/test", json=request_data)
-        
+
         assert response.status_code == 200
         data = response.json()
         assert data["success"] is False
@@ -173,11 +174,11 @@ class TestBackupAPI:
                 "endpoint_url": None,
                 "path_style": False,
                 "enabled": True,
-            }
+            },
         }
-        
+
         response = api_client.post("/api/v1/backup/test", json=request_data)
-        
+
         assert response.status_code == 400
         data = response.json()
         assert "Only 's3' service is supported" in data["detail"]
@@ -197,7 +198,7 @@ class TestBackupAPI:
                 "size": 512,
             },
         ]
-        
+
         mock_config._config["backup"] = {
             "s3": {
                 "access_key_id": "AKIATEST123",
@@ -207,23 +208,26 @@ class TestBackupAPI:
                 "enabled": True,
             }
         }
-        
+
         with patch("leggen.utils.config.config", mock_config):
             response = api_client.get("/api/v1/backup/list")
-        
+
         assert response.status_code == 200
         data = response.json()
         assert data["success"] is True
         assert len(data["data"]) == 2
-        assert data["data"][0]["key"] == "leggen_backups/database_backup_20250101_120000.db"
+        assert (
+            data["data"][0]["key"]
+            == "leggen_backups/database_backup_20250101_120000.db"
+        )
 
     def test_list_backups_no_config(self, api_client, mock_config):
         """Test backup listing with no configuration."""
         mock_config._config["backup"] = {}
-        
+
         with patch("leggen.utils.config.config", mock_config):
             response = api_client.get("/api/v1/backup/list")
-        
+
         assert response.status_code == 200
         data = response.json()
         assert data["success"] is True
@@ -231,13 +235,15 @@ class TestBackupAPI:
 
     @patch("leggen.services.backup_service.BackupService.backup_database")
     @patch("leggen.utils.paths.path_manager.get_database_path")
-    def test_backup_operation_success(self, mock_get_db_path, mock_backup_db, api_client, mock_config):
+    def test_backup_operation_success(
+        self, mock_get_db_path, mock_backup_db, api_client, mock_config
+    ):
         """Test successful backup operation."""
         from pathlib import Path
-        
+
         mock_get_db_path.return_value = Path("/test/database.db")
         mock_backup_db.return_value = True
-        
+
         mock_config._config["backup"] = {
             "s3": {
                 "access_key_id": "AKIATEST123",
@@ -247,30 +253,30 @@ class TestBackupAPI:
                 "enabled": True,
             }
         }
-        
+
         request_data = {"operation": "backup"}
-        
+
         with patch("leggen.utils.config.config", mock_config):
             response = api_client.post("/api/v1/backup/operation", json=request_data)
-        
+
         assert response.status_code == 200
         data = response.json()
         assert data["success"] is True
         assert data["data"]["operation"] == "backup"
         assert data["data"]["completed"] is True
-        
+
         # Verify backup was called
         mock_backup_db.assert_called_once()
 
     def test_backup_operation_no_config(self, api_client, mock_config):
         """Test backup operation with no configuration."""
         mock_config._config["backup"] = {}
-        
+
         request_data = {"operation": "backup"}
-        
+
         with patch("leggen.utils.config.config", mock_config):
             response = api_client.post("/api/v1/backup/operation", json=request_data)
-        
+
         assert response.status_code == 400
         data = response.json()
         assert "S3 backup is not configured" in data["detail"]
@@ -286,12 +292,12 @@ class TestBackupAPI:
                 "enabled": True,
             }
         }
-        
+
         request_data = {"operation": "invalid"}
-        
+
         with patch("leggen.utils.config.config", mock_config):
             response = api_client.post("/api/v1/backup/operation", json=request_data)
-        
+
         assert response.status_code == 400
         data = response.json()
-        assert "Invalid operation" in data["detail"]
\ No newline at end of file
+        assert "Invalid operation" in data["detail"]
diff --git a/tests/unit/test_backup_service.py b/tests/unit/test_backup_service.py
index 14353af..89035b4 100644
--- a/tests/unit/test_backup_service.py
+++ b/tests/unit/test_backup_service.py
@@ -2,7 +2,7 @@
 
 import tempfile
 from pathlib import Path
-from unittest.mock import AsyncMock, MagicMock, patch
+from unittest.mock import MagicMock, patch
 
 import pytest
 from botocore.exceptions import ClientError, NoCredentialsError
@@ -41,20 +41,20 @@ class TestBackupService:
             bucket_name="test-bucket",
             region="us-east-1",
         )
-        
+
         service = BackupService()
-        
+
         # Mock S3 client
         with patch("boto3.Session") as mock_session:
             mock_client = MagicMock()
             mock_session.return_value.client.return_value = mock_client
-            
+
             # Mock successful list_objects_v2 call
             mock_client.list_objects_v2.return_value = {"Contents": []}
-            
+
             result = await service.test_connection(s3_config)
             assert result is True
-            
+
             # Verify the client was called correctly
             mock_client.list_objects_v2.assert_called_once_with(
                 Bucket="test-bucket", MaxKeys=1
@@ -69,15 +69,15 @@ class TestBackupService:
             bucket_name="test-bucket",
             region="us-east-1",
         )
-        
+
         service = BackupService()
-        
+
         # Mock S3 client to raise NoCredentialsError
         with patch("boto3.Session") as mock_session:
             mock_client = MagicMock()
             mock_session.return_value.client.return_value = mock_client
             mock_client.list_objects_v2.side_effect = NoCredentialsError()
-            
+
             result = await service.test_connection(s3_config)
             assert result is False
 
@@ -90,16 +90,20 @@ class TestBackupService:
             bucket_name="test-bucket",
             region="us-east-1",
         )
-        
+
         service = BackupService()
-        
+
         # Mock S3 client to raise ClientError
         with patch("boto3.Session") as mock_session:
             mock_client = MagicMock()
             mock_session.return_value.client.return_value = mock_client
-            error_response = {"Error": {"Code": "NoSuchBucket", "Message": "Bucket not found"}}
-            mock_client.list_objects_v2.side_effect = ClientError(error_response, "ListObjectsV2")
-            
+            error_response = {
+                "Error": {"Code": "NoSuchBucket", "Message": "Bucket not found"}
+            }
+            mock_client.list_objects_v2.side_effect = ClientError(
+                error_response, "ListObjectsV2"
+            )
+
             result = await service.test_connection(s3_config)
             assert result is False
 
@@ -107,11 +111,11 @@ class TestBackupService:
     async def test_backup_database_no_config(self):
         """Test backup database with no configuration."""
         service = BackupService()
-        
+
         with tempfile.TemporaryDirectory() as tmpdir:
             db_path = Path(tmpdir) / "test.db"
             db_path.write_text("test database content")
-            
+
             result = await service.backup_database(db_path)
             assert result is False
 
@@ -126,11 +130,11 @@ class TestBackupService:
             enabled=False,
         )
         service = BackupService(s3_config)
-        
+
         with tempfile.TemporaryDirectory() as tmpdir:
             db_path = Path(tmpdir) / "test.db"
             db_path.write_text("test database content")
-            
+
             result = await service.backup_database(db_path)
             assert result is False
 
@@ -144,7 +148,7 @@ class TestBackupService:
             region="us-east-1",
         )
         service = BackupService(s3_config)
-        
+
         non_existent_path = Path("/non/existent/path.db")
         result = await service.backup_database(non_existent_path)
         assert result is False
@@ -159,19 +163,19 @@ class TestBackupService:
             region="us-east-1",
         )
         service = BackupService(s3_config)
-        
+
         with tempfile.TemporaryDirectory() as tmpdir:
             db_path = Path(tmpdir) / "test.db"
             db_path.write_text("test database content")
-            
+
             # Mock S3 client
             with patch("boto3.Session") as mock_session:
                 mock_client = MagicMock()
                 mock_session.return_value.client.return_value = mock_client
-                
+
                 result = await service.backup_database(db_path)
                 assert result is True
-                
+
                 # Verify upload_file was called
                 mock_client.upload_file.assert_called_once()
                 args = mock_client.upload_file.call_args[0]
@@ -189,13 +193,14 @@ class TestBackupService:
             region="us-east-1",
         )
         service = BackupService(s3_config)
-        
+
         # Mock S3 client response
         with patch("boto3.Session") as mock_session:
             mock_client = MagicMock()
             mock_session.return_value.client.return_value = mock_client
-            
+
             from datetime import datetime
+
             mock_response = {
                 "Contents": [
                     {
@@ -211,11 +216,11 @@ class TestBackupService:
                 ]
             }
             mock_client.list_objects_v2.return_value = mock_response
-            
+
             backups = await service.list_backups()
             assert len(backups) == 2
-            
+
             # Check that backups are sorted by last modified (newest first)
             assert backups[0]["last_modified"] > backups[1]["last_modified"]
             assert backups[0]["size"] == 2048
-            assert backups[1]["size"] == 1024
\ No newline at end of file
+            assert backups[1]["size"] == 1024