diff --git a/packages/backend/package.json b/packages/backend/package.json
index 600564b..829ffc5 100644
--- a/packages/backend/package.json
+++ b/packages/backend/package.json
@@ -40,6 +40,9 @@
 		"express-validator": "^7.2.1",
 		"google-auth-library": "^10.1.0",
 		"googleapis": "^152.0.0",
+		"i18next": "^25.4.2",
+		"i18next-fs-backend": "^2.6.0",
+		"i18next-http-middleware": "^3.8.0",
 		"imapflow": "^1.0.191",
 		"jose": "^6.0.11",
 		"mailparser": "^3.7.4",
diff --git a/packages/backend/src/api/controllers/archived-email.controller.ts b/packages/backend/src/api/controllers/archived-email.controller.ts
index dc64c7f..19a991a 100644
--- a/packages/backend/src/api/controllers/archived-email.controller.ts
+++ b/packages/backend/src/api/controllers/archived-email.controller.ts
@@ -11,7 +11,7 @@ export class ArchivedEmailController {
 			const userId = req.user?.sub;
 
 			if (!userId) {
-				return res.status(401).json({ message: 'Unauthorized' });
+				return res.status(401).json({ message: req.t('errors.unauthorized') });
 			}
 
 			const result = await ArchivedEmailService.getArchivedEmails(
@@ -23,7 +23,7 @@ export class ArchivedEmailController {
 			return res.status(200).json(result);
 		} catch (error) {
 			console.error('Get archived emails error:', error);
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 
@@ -33,23 +33,23 @@ export class ArchivedEmailController {
 			const userId = req.user?.sub;
 
 			if (!userId) {
-				return res.status(401).json({ message: 'Unauthorized' });
+				return res.status(401).json({ message: req.t('errors.unauthorized') });
 			}
 
 			const email = await ArchivedEmailService.getArchivedEmailById(id, userId);
 			if (!email) {
-				return res.status(404).json({ message: 'Archived email not found' });
+				return res.status(404).json({ message: req.t('archivedEmail.notFound') });
 			}
 			return res.status(200).json(email);
 		} catch (error) {
 			console.error(`Get archived email by id ${req.params.id} error:`, error);
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 
 	public deleteArchivedEmail = async (req: Request, res: Response): Promise<Response> => {
 		if (config.app.isDemo) {
-			return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+			return res.status(403).json({ message: req.t('errors.demoMode') });
 		}
 		try {
 			const { id } = req.params;
@@ -59,11 +59,11 @@ export class ArchivedEmailController {
 			console.error(`Delete archived email ${req.params.id} error:`, error);
 			if (error instanceof Error) {
 				if (error.message === 'Archived email not found') {
-					return res.status(404).json({ message: error.message });
+					return res.status(404).json({ message: req.t('archivedEmail.notFound') });
 				}
 				return res.status(500).json({ message: error.message });
 			}
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 }
diff --git a/packages/backend/src/api/controllers/auth.controller.ts b/packages/backend/src/api/controllers/auth.controller.ts
index 9ef6904..a692401 100644
--- a/packages/backend/src/api/controllers/auth.controller.ts
+++ b/packages/backend/src/api/controllers/auth.controller.ts
@@ -27,7 +27,7 @@ export class AuthController {
 		const { email, password, first_name, last_name } = req.body;
 
 		if (!email || !password || !first_name || !last_name) {
-			return res.status(400).json({ message: 'Email, password, and name are required' });
+			return res.status(400).json({ message: req.t('auth.setup.allFieldsRequired') });
 		}
 
 		try {
@@ -37,7 +37,7 @@ export class AuthController {
 			const userCount = Number(userCountResult[0].count);
 
 			if (userCount > 0) {
-				return res.status(403).json({ message: 'Setup has already been completed.' });
+				return res.status(403).json({ message: req.t('auth.setup.alreadyCompleted') });
 			}
 
 			const newUser = await this.#userService.createAdminUser(
@@ -48,7 +48,7 @@ export class AuthController {
 			return res.status(201).json(result);
 		} catch (error) {
 			console.error('Setup error:', error);
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 
@@ -56,20 +56,20 @@ export class AuthController {
 		const { email, password } = req.body;
 
 		if (!email || !password) {
-			return res.status(400).json({ message: 'Email and password are required' });
+			return res.status(400).json({ message: req.t('auth.login.emailAndPasswordRequired') });
 		}
 
 		try {
 			const result = await this.#authService.login(email, password);
 
 			if (!result) {
-				return res.status(401).json({ message: 'Invalid credentials' });
+				return res.status(401).json({ message: req.t('auth.login.invalidCredentials') });
 			}
 
 			return res.status(200).json(result);
 		} catch (error) {
 			console.error('Login error:', error);
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 
@@ -124,7 +124,7 @@ export class AuthController {
 			return res.status(200).json({ needsSetupUser });
 		} catch (error) {
 			console.error('Status check error:', error);
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 }
diff --git a/packages/backend/src/api/controllers/iam.controller.ts b/packages/backend/src/api/controllers/iam.controller.ts
index 60600fb..713e908 100644
--- a/packages/backend/src/api/controllers/iam.controller.ts
+++ b/packages/backend/src/api/controllers/iam.controller.ts
@@ -22,7 +22,7 @@ export class IamController {
 			}
 			res.status(200).json(roles);
 		} catch (error) {
-			res.status(500).json({ message: 'Failed to get roles.' });
+			res.status(500).json({ message: req.t('iam.failedToGetRoles') });
 		}
 	};
 
@@ -34,21 +34,21 @@ export class IamController {
 			if (role) {
 				res.status(200).json(role);
 			} else {
-				res.status(404).json({ message: 'Role not found.' });
+				res.status(404).json({ message: req.t('iam.roleNotFound') });
 			}
 		} catch (error) {
-			res.status(500).json({ message: 'Failed to get role.' });
+			res.status(500).json({ message: req.t('iam.failedToGetRole') });
 		}
 	};
 
 	public createRole = async (req: Request, res: Response) => {
 		if (config.app.isDemo) {
-			return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+			return res.status(403).json({ message: req.t('errors.demoMode') });
 		}
 		const { name, policies } = req.body;
 
 		if (!name || !policies) {
-			res.status(400).json({ message: 'Missing required fields: name and policy.' });
+			res.status(400).json({ message: req.t('iam.missingRoleFields') });
 			return;
 		}
 
@@ -56,7 +56,7 @@ export class IamController {
 			for (const statement of policies) {
 				const { valid, reason } = PolicyValidator.isValid(statement as CaslPolicy);
 				if (!valid) {
-					res.status(400).json({ message: `Invalid policy statement: ${reason}` });
+					res.status(400).json({ message: `${req.t('iam.invalidPolicy')} ${reason}` });
 					return;
 				}
 			}
@@ -64,13 +64,13 @@ export class IamController {
 			res.status(201).json(role);
 		} catch (error) {
 			console.log(error);
-			res.status(500).json({ message: 'Failed to create role.' });
+			res.status(500).json({ message: req.t('iam.failedToCreateRole') });
 		}
 	};
 
 	public deleteRole = async (req: Request, res: Response) => {
 		if (config.app.isDemo) {
-			return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+			return res.status(403).json({ message: req.t('errors.demoMode') });
 		}
 		const { id } = req.params;
 
@@ -78,19 +78,19 @@ export class IamController {
 			await this.#iamService.deleteRole(id);
 			res.status(204).send();
 		} catch (error) {
-			res.status(500).json({ message: 'Failed to delete role.' });
+			res.status(500).json({ message: req.t('iam.failedToDeleteRole') });
 		}
 	};
 
 	public updateRole = async (req: Request, res: Response) => {
 		if (config.app.isDemo) {
-			return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+			return res.status(403).json({ message: req.t('errors.demoMode') });
 		}
 		const { id } = req.params;
 		const { name, policies } = req.body;
 
 		if (!name && !policies) {
-			res.status(400).json({ message: 'Missing fields to update: name or policies.' });
+			res.status(400).json({ message: req.t('iam.missingUpdateFields') });
 			return;
 		}
 
@@ -98,7 +98,7 @@ export class IamController {
 			for (const statement of policies) {
 				const { valid, reason } = PolicyValidator.isValid(statement as CaslPolicy);
 				if (!valid) {
-					res.status(400).json({ message: `Invalid policy statement: ${reason}` });
+					res.status(400).json({ message: `${req.t('iam.invalidPolicy')} ${reason}` });
 					return;
 				}
 			}
@@ -108,7 +108,7 @@ export class IamController {
 			const role = await this.#iamService.updateRole(id, { name, policies });
 			res.status(200).json(role);
 		} catch (error) {
-			res.status(500).json({ message: 'Failed to update role.' });
+			res.status(500).json({ message: req.t('iam.failedToUpdateRole') });
 		}
 	};
 
diff --git a/packages/backend/src/api/controllers/ingestion.controller.ts b/packages/backend/src/api/controllers/ingestion.controller.ts
index b7e4d2a..944b2da 100644
--- a/packages/backend/src/api/controllers/ingestion.controller.ts
+++ b/packages/backend/src/api/controllers/ingestion.controller.ts
@@ -23,13 +23,13 @@ export class IngestionController {
 
 	public create = async (req: Request, res: Response): Promise<Response> => {
 		if (config.app.isDemo) {
-			return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+			return res.status(403).json({ message: req.t('errors.demoMode') });
 		}
 		try {
 			const dto: CreateIngestionSourceDto = req.body;
 			const userId = req.user?.sub;
 			if (!userId) {
-				return res.status(401).json({ message: 'Unauthorized' });
+				return res.status(401).json({ message: req.t('errors.unauthorized') });
 			}
 			const newSource = await IngestionService.create(dto, userId);
 			const safeSource = this.toSafeIngestionSource(newSource);
@@ -39,7 +39,7 @@ export class IngestionController {
 			// Return a 400 Bad Request for connection errors
 			return res.status(400).json({
 				message:
-					error.message || 'Failed to create ingestion source due to a connection error.',
+					error.message || req.t('ingestion.failedToCreate'),
 			});
 		}
 	};
@@ -48,14 +48,14 @@ export class IngestionController {
 		try {
 			const userId = req.user?.sub;
 			if (!userId) {
-				return res.status(401).json({ message: 'Unauthorized' });
+				return res.status(401).json({ message: req.t('errors.unauthorized') });
 			}
 			const sources = await IngestionService.findAll(userId);
 			const safeSources = sources.map(this.toSafeIngestionSource);
 			return res.status(200).json(safeSources);
 		} catch (error) {
 			console.error('Find all ingestion sources error:', error);
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 
@@ -68,15 +68,15 @@ export class IngestionController {
 		} catch (error) {
 			console.error(`Find ingestion source by id ${req.params.id} error:`, error);
 			if (error instanceof Error && error.message === 'Ingestion source not found') {
-				return res.status(404).json({ message: error.message });
+				return res.status(404).json({ message: req.t('ingestion.notFound') });
 			}
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 
 	public update = async (req: Request, res: Response): Promise<Response> => {
 		if (config.app.isDemo) {
-			return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+			return res.status(403).json({ message: req.t('errors.demoMode') });
 		}
 		try {
 			const { id } = req.params;
@@ -87,15 +87,15 @@ export class IngestionController {
 		} catch (error) {
 			console.error(`Update ingestion source ${req.params.id} error:`, error);
 			if (error instanceof Error && error.message === 'Ingestion source not found') {
-				return res.status(404).json({ message: error.message });
+				return res.status(404).json({ message: req.t('ingestion.notFound') });
 			}
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 
 	public delete = async (req: Request, res: Response): Promise<Response> => {
 		if (config.app.isDemo) {
-			return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+			return res.status(403).json({ message: req.t('errors.demoMode') });
 		}
 		try {
 			const { id } = req.params;
@@ -104,32 +104,32 @@ export class IngestionController {
 		} catch (error) {
 			console.error(`Delete ingestion source ${req.params.id} error:`, error);
 			if (error instanceof Error && error.message === 'Ingestion source not found') {
-				return res.status(404).json({ message: error.message });
+				return res.status(404).json({ message: req.t('ingestion.notFound') });
 			}
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 
 	public triggerInitialImport = async (req: Request, res: Response): Promise<Response> => {
 		if (config.app.isDemo) {
-			return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+			return res.status(403).json({ message: req.t('errors.demoMode') });
 		}
 		try {
 			const { id } = req.params;
 			await IngestionService.triggerInitialImport(id);
-			return res.status(202).json({ message: 'Initial import triggered successfully.' });
+			return res.status(202).json({ message: req.t('ingestion.initialImportTriggered') });
 		} catch (error) {
 			console.error(`Trigger initial import for ${req.params.id} error:`, error);
 			if (error instanceof Error && error.message === 'Ingestion source not found') {
-				return res.status(404).json({ message: error.message });
+				return res.status(404).json({ message: req.t('ingestion.notFound') });
 			}
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 
 	public pause = async (req: Request, res: Response): Promise<Response> => {
 		if (config.app.isDemo) {
-			return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+			return res.status(403).json({ message: req.t('errors.demoMode') });
 		}
 		try {
 			const { id } = req.params;
@@ -139,26 +139,26 @@ export class IngestionController {
 		} catch (error) {
 			console.error(`Pause ingestion source ${req.params.id} error:`, error);
 			if (error instanceof Error && error.message === 'Ingestion source not found') {
-				return res.status(404).json({ message: error.message });
+				return res.status(404).json({ message: req.t('ingestion.notFound') });
 			}
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 
 	public triggerForceSync = async (req: Request, res: Response): Promise<Response> => {
 		if (config.app.isDemo) {
-			return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+			return res.status(403).json({ message: req.t('errors.demoMode') });
 		}
 		try {
 			const { id } = req.params;
 			await IngestionService.triggerForceSync(id);
-			return res.status(202).json({ message: 'Force sync triggered successfully.' });
+			return res.status(202).json({ message: req.t('ingestion.forceSyncTriggered') });
 		} catch (error) {
 			console.error(`Trigger force sync for ${req.params.id} error:`, error);
 			if (error instanceof Error && error.message === 'Ingestion source not found') {
-				return res.status(404).json({ message: error.message });
+				return res.status(404).json({ message: req.t('ingestion.notFound') });
 			}
-			return res.status(500).json({ message: 'An internal server error occurred' });
+			return res.status(500).json({ message: req.t('errors.internalServerError') });
 		}
 	};
 }
diff --git a/packages/backend/src/api/controllers/search.controller.ts b/packages/backend/src/api/controllers/search.controller.ts
index 7917f93..a7c86ee 100644
--- a/packages/backend/src/api/controllers/search.controller.ts
+++ b/packages/backend/src/api/controllers/search.controller.ts
@@ -15,12 +15,12 @@ export class SearchController {
 			const userId = req.user?.sub;
 
 			if (!userId) {
-				res.status(401).json({ message: 'Unauthorized' });
+				res.status(401).json({ message: req.t('errors.unauthorized') });
 				return;
 			}
 
 			if (!keywords) {
-				res.status(400).json({ message: 'Keywords are required' });
+				res.status(400).json({ message: req.t('search.keywordsRequired') });
 				return;
 			}
 
@@ -36,7 +36,7 @@ export class SearchController {
 
 			res.status(200).json(results);
 		} catch (error) {
-			const message = error instanceof Error ? error.message : 'An unknown error occurred';
+			const message = error instanceof Error ? error.message : req.t('errors.unknown');
 			res.status(500).json({ message });
 		}
 	};
diff --git a/packages/backend/src/api/controllers/settings.controller.ts b/packages/backend/src/api/controllers/settings.controller.ts
index c6044a2..36d5daa 100644
--- a/packages/backend/src/api/controllers/settings.controller.ts
+++ b/packages/backend/src/api/controllers/settings.controller.ts
@@ -9,7 +9,7 @@ export const getSettings = async (req: Request, res: Response) => {
         res.status(200).json(settings);
     } catch (error) {
         // A more specific error could be logged here
-        res.status(500).json({ message: 'Failed to retrieve settings' });
+        res.status(500).json({ message: req.t('settings.failedToRetrieve') });
     }
 };
 
@@ -20,6 +20,6 @@ export const updateSettings = async (req: Request, res: Response) => {
         res.status(200).json(updatedSettings);
     } catch (error) {
         // A more specific error could be logged here
-        res.status(500).json({ message: 'Failed to update settings' });
+        res.status(500).json({ message: req.t('settings.failedToUpdate') });
     }
 };
diff --git a/packages/backend/src/api/controllers/storage.controller.ts b/packages/backend/src/api/controllers/storage.controller.ts
index f836692..38697f4 100644
--- a/packages/backend/src/api/controllers/storage.controller.ts
+++ b/packages/backend/src/api/controllers/storage.controller.ts
@@ -4,13 +4,13 @@ import * as path from 'path';
 import { storage as storageConfig } from '../../config/storage';
 
 export class StorageController {
-	constructor(private storageService: StorageService) {}
+	constructor(private storageService: StorageService) { }
 
 	public downloadFile = async (req: Request, res: Response): Promise<void> => {
 		const unsafePath = req.query.path as string;
 
 		if (!unsafePath) {
-			res.status(400).send('File path is required');
+			res.status(400).send(req.t('storage.filePathRequired'));
 			return;
 		}
 
@@ -24,7 +24,7 @@ export class StorageController {
 		const fullPath = path.join(basePath, normalizedPath);
 
 		if (!fullPath.startsWith(basePath)) {
-			res.status(400).send('Invalid file path');
+			res.status(400).send(req.t('storage.invalidFilePath'));
 			return;
 		}
 
@@ -34,7 +34,7 @@ export class StorageController {
 		try {
 			const fileExists = await this.storageService.exists(safePath);
 			if (!fileExists) {
-				res.status(404).send('File not found');
+				res.status(404).send(req.t('storage.fileNotFound'));
 				return;
 			}
 
@@ -44,7 +44,7 @@ export class StorageController {
 			fileStream.pipe(res);
 		} catch (error) {
 			console.error('Error downloading file:', error);
-			res.status(500).send('Error downloading file');
+			res.status(500).send(req.t('storage.downloadError'));
 		}
 	};
 }
diff --git a/packages/backend/src/api/controllers/user.controller.ts b/packages/backend/src/api/controllers/user.controller.ts
index 7a10407..940e043 100644
--- a/packages/backend/src/api/controllers/user.controller.ts
+++ b/packages/backend/src/api/controllers/user.controller.ts
@@ -15,14 +15,14 @@ export const getUsers = async (req: Request, res: Response) => {
 export const getUser = async (req: Request, res: Response) => {
 	const user = await userService.findById(req.params.id);
 	if (!user) {
-		return res.status(404).json({ message: 'User not found' });
+		return res.status(404).json({ message: req.t('user.notFound') });
 	}
 	res.json(user);
 };
 
 export const createUser = async (req: Request, res: Response) => {
 	if (config.app.isDemo) {
-		return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+		return res.status(403).json({ message: req.t('errors.demoMode') });
 	}
 	const { email, first_name, last_name, password, roleId } = req.body;
 
@@ -35,7 +35,7 @@ export const createUser = async (req: Request, res: Response) => {
 
 export const updateUser = async (req: Request, res: Response) => {
 	if (config.app.isDemo) {
-		return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+		return res.status(403).json({ message: req.t('errors.demoMode') });
 	}
 	const { email, first_name, last_name, roleId } = req.body;
 	const updatedUser = await userService.updateUser(
@@ -44,21 +44,21 @@ export const updateUser = async (req: Request, res: Response) => {
 		roleId
 	);
 	if (!updatedUser) {
-		return res.status(404).json({ message: 'User not found' });
+		return res.status(404).json({ message: req.t('user.notFound') });
 	}
 	res.json(updatedUser);
 };
 
 export const deleteUser = async (req: Request, res: Response) => {
 	if (config.app.isDemo) {
-		return res.status(403).json({ message: 'This operation is not allowed in demo mode.' });
+		return res.status(403).json({ message: req.t('errors.demoMode') });
 	}
 	const userCountResult = await db.select({ count: sql<number>`count(*)` }).from(schema.users);
-	console.log('iusercount,', userCountResult[0].count);
+
 	const isOnlyUser = Number(userCountResult[0].count) === 1;
 	if (isOnlyUser) {
 		return res.status(400).json({
-			message: 'You are trying to delete the only user in the database, this is not allowed.',
+			message: req.t('user.cannotDeleteOnlyUser'),
 		});
 	}
 	await userService.deleteUser(req.params.id);
diff --git a/packages/backend/src/index.ts b/packages/backend/src/index.ts
index 1f1b1b3..0d0d9b7 100644
--- a/packages/backend/src/index.ts
+++ b/packages/backend/src/index.ts
@@ -22,6 +22,12 @@ import { UserService } from './services/UserService';
 import { IamService } from './services/IamService';
 import { StorageService } from './services/StorageService';
 import { SearchService } from './services/SearchService';
+import { SettingsService } from './services/SettingsService';
+import i18next from 'i18next';
+import FsBackend from 'i18next-fs-backend';
+import i18nextMiddleware from 'i18next-http-middleware';
+import path from 'path';
+import { logger } from './config/logger';
 
 // Load environment variables
 dotenv.config();
@@ -48,6 +54,25 @@ const searchService = new SearchService();
 const searchController = new SearchController();
 const iamService = new IamService();
 const iamController = new IamController(iamService);
+const settingsService = new SettingsService();
+
+// --- i18next Initialization ---
+const initializeI18next = async () => {
+	const systemSettings = await settingsService.getSettings();
+	const defaultLanguage = systemSettings?.language || 'en';
+	logger.info({ language: defaultLanguage }, 'Default language');
+	await i18next
+		.use(FsBackend)
+		.init({
+			lng: defaultLanguage,
+			fallbackLng: defaultLanguage,
+			ns: ['translation'],
+			defaultNS: 'translation',
+			backend: {
+				loadPath: path.resolve(__dirname, './locales/{{lng}}/{{ns}}.json'),
+			},
+		});
+};
 
 // --- Express App Initialization ---
 const app = express();
@@ -70,6 +95,9 @@ app.use('/v1/upload', uploadRouter);
 app.use(express.json());
 app.use(express.urlencoded({ extended: true }));
 
+// i18n middleware
+app.use(i18nextMiddleware.handle(i18next));
+
 app.use('/v1/auth', authRouter);
 app.use('/v1/iam', iamRouter);
 app.use('/v1/ingestion-sources', ingestionRouter);
@@ -95,15 +123,19 @@ app.get('/', (req, res) => {
 // --- Server Start ---
 const startServer = async () => {
 	try {
+		// Initialize i18next
+		await initializeI18next();
+		logger.info({}, 'i18next initialized');
+
 		// Configure the Meilisearch index on startup
-		console.log('Configuring email index...');
+		logger.info({}, 'Configuring email index...');
 		await searchService.configureEmailIndex();
 
 		app.listen(PORT_BACKEND, () => {
-			console.log(`Backend listening at http://localhost:${PORT_BACKEND}`);
+			logger.info({}, `Backend listening at http://localhost:${PORT_BACKEND}`);
 		});
 	} catch (error) {
-		console.error('Failed to start the server:', error);
+		logger.error({ error }, 'Failed to start the server:', error);
 		process.exit(1);
 	}
 };
diff --git a/packages/backend/src/locales/de/translation.json b/packages/backend/src/locales/de/translation.json
new file mode 100644
index 0000000..4a2dbd4
--- /dev/null
+++ b/packages/backend/src/locales/de/translation.json
@@ -0,0 +1,55 @@
+{
+	"auth": {
+		"setup": {
+			"allFieldsRequired": "E-Mail, Passwort und Name sind erforderlich",
+			"alreadyCompleted": "Die Einrichtung wurde bereits abgeschlossen."
+		},
+		"login": {
+			"emailAndPasswordRequired": "E-Mail und Passwort sind erforderlich",
+			"invalidCredentials": "Ungültige Anmeldeinformationen"
+		}
+	},
+	"errors": {
+		"internalServerError": "Ein interner Serverfehler ist aufgetreten",
+		"demoMode": "Dieser Vorgang ist im Demo-Modus nicht zulässig.",
+		"unauthorized": "Unbefugt",
+		"unknown": "Ein unbekannter Fehler ist aufgetreten"
+	},
+	"user": {
+		"notFound": "Benutzer nicht gefunden",
+		"cannotDeleteOnlyUser": "Sie versuchen, den einzigen Benutzer in der Datenbank zu löschen, dies ist nicht gestattet."
+	},
+	"iam": {
+		"failedToGetRoles": "Rollen konnten nicht abgerufen werden.",
+		"roleNotFound": "Rolle nicht gefunden.",
+		"failedToGetRole": "Rolle konnte nicht abgerufen werden.",
+		"missingRoleFields": "Fehlende erforderliche Felder: Name und Richtlinie.",
+		"invalidPolicy": "Ungültige Richtlinienanweisung:",
+		"failedToCreateRole": "Rolle konnte nicht erstellt werden.",
+		"failedToDeleteRole": "Rolle konnte nicht gelöscht werden.",
+		"missingUpdateFields": "Fehlende Felder zum Aktualisieren: Name oder Richtlinien.",
+		"failedToUpdateRole": "Rolle konnte nicht aktualisiert werden."
+	},
+	"settings": {
+		"failedToRetrieve": "Einstellungen konnten nicht abgerufen werden",
+		"failedToUpdate": "Einstellungen konnten nicht aktualisiert werden"
+	},
+	"ingestion": {
+		"failedToCreate": "Die Erfassungsquelle konnte aufgrund eines Verbindungsfehlers nicht erstellt werden.",
+		"notFound": "Erfassungsquelle nicht gefunden",
+		"initialImportTriggered": "Der erstmalige Import wurde erfolgreich ausgelöst.",
+		"forceSyncTriggered": "Die Zwangssynchronisierung wurde erfolgreich ausgelöst."
+	},
+	"archivedEmail": {
+		"notFound": "Archivierte E-Mail nicht gefunden"
+	},
+	"search": {
+		"keywordsRequired": "Schlüsselwörter sind erforderlich"
+	},
+	"storage": {
+		"filePathRequired": "Dateipfad ist erforderlich",
+		"invalidFilePath": "Ungültiger Dateipfad",
+		"fileNotFound": "Datei nicht gefunden",
+		"downloadError": "Fehler beim Herunterladen der Datei"
+	}
+}
diff --git a/packages/backend/src/locales/el/translation.json b/packages/backend/src/locales/el/translation.json
new file mode 100644
index 0000000..97c3b87
--- /dev/null
+++ b/packages/backend/src/locales/el/translation.json
@@ -0,0 +1,55 @@
+{
+	"auth": {
+		"setup": {
+			"allFieldsRequired": "Το email, ο κωδικός πρόσβασης και το όνομα είναι υποχρεωτικά",
+			"alreadyCompleted": "Η εγκατάσταση έχει ήδη ολοκληρωθεί."
+		},
+		"login": {
+			"emailAndPasswordRequired": "Το email και ο κωδικός πρόσβασης είναι υποχρεωτικά",
+			"invalidCredentials": "Μη έγκυρα διαπιστευτήρια"
+		}
+	},
+	"errors": {
+		"internalServerError": "Παρουσιάστηκε ένα εσωτερικό σφάλμα διακομιστή",
+		"demoMode": "Αυτή η λειτουργία δεν επιτρέπεται σε λειτουργία επίδειξης.",
+		"unauthorized": "Μη εξουσιοδοτημένο",
+		"unknown": "Παρουσιάστηκε ένα άγνωστο σφάλμα"
+	},
+	"user": {
+		"notFound": "Ο χρήστης δεν βρέθηκε",
+		"cannotDeleteOnlyUser": "Προσπαθείτε να διαγράψετε τον μοναδικό χρήστη στη βάση δεδομένων, αυτό δεν επιτρέπεται."
+	},
+	"iam": {
+		"failedToGetRoles": "Η λήψη των ρόλων απέτυχε.",
+		"roleNotFound": "Ο ρόλος δεν βρέθηκε.",
+		"failedToGetRole": "Η λήψη του ρόλου απέτυχε.",
+		"missingRoleFields": "Λείπουν τα απαιτούμενα πεδία: όνομα και πολιτική.",
+		"invalidPolicy": "Μη έγκυρη δήλωση πολιτικής:",
+		"failedToCreateRole": "Η δημιουργία του ρόλου απέτυχε.",
+		"failedToDeleteRole": "Η διαγραφή του ρόλου απέτυχε.",
+		"missingUpdateFields": "Λείπουν πεδία για ενημέρωση: όνομα ή πολιτικές.",
+		"failedToUpdateRole": "Η ενημέρωση του ρόλου απέτυχε."
+	},
+	"settings": {
+		"failedToRetrieve": "Η ανάκτηση των ρυθμίσεων απέτυχε",
+		"failedToUpdate": "Η ενημέρωση των ρυθμίσεων απέτυχε"
+	},
+	"ingestion": {
+		"failedToCreate": "Η δημιουργία της πηγής πρόσληψης απέτυχε λόγω σφάλματος σύνδεσης.",
+		"notFound": "Η πηγή πρόσληψης δεν βρέθηκε",
+		"initialImportTriggered": "Η αρχική εισαγωγή ενεργοποιήθηκε με επιτυχία.",
+		"forceSyncTriggered": "Ο εξαναγκασμένος συγχρονισμός ενεργοποιήθηκε με επιτυχία."
+	},
+	"archivedEmail": {
+		"notFound": "Το αρχειοθετημένο email δεν βρέθηκε"
+	},
+	"search": {
+		"keywordsRequired": "Απαιτούνται λέξεις-κλειδιά"
+	},
+	"storage": {
+		"filePathRequired": "Απαιτείται η διαδρομή του αρχείου",
+		"invalidFilePath": "Μη έγκυρη διαδρομή αρχείου",
+		"fileNotFound": "Το αρχείο δεν βρέθηκε",
+		"downloadError": "Σφάλμα κατά τη λήψη του αρχείου"
+	}
+}
diff --git a/packages/backend/src/locales/en/translation.json b/packages/backend/src/locales/en/translation.json
new file mode 100644
index 0000000..d2c8c4d
--- /dev/null
+++ b/packages/backend/src/locales/en/translation.json
@@ -0,0 +1,55 @@
+{
+	"auth": {
+		"setup": {
+			"allFieldsRequired": "Email, password, and name are required",
+			"alreadyCompleted": "Setup has already been completed."
+		},
+		"login": {
+			"emailAndPasswordRequired": "Email and password are required",
+			"invalidCredentials": "Invalid credentials this is a translation"
+		}
+	},
+	"errors": {
+		"internalServerError": "An internal server error occurred",
+		"demoMode": "This operation is not allowed in demo mode.",
+		"unauthorized": "Unauthorized",
+		"unknown": "An unknown error occurred"
+	},
+	"user": {
+		"notFound": "User not found",
+		"cannotDeleteOnlyUser": "You are trying to delete the only user in the database, this is not allowed."
+	},
+	"iam": {
+		"failedToGetRoles": "Failed to get roles.",
+		"roleNotFound": "Role not found.",
+		"failedToGetRole": "Failed to get role.",
+		"missingRoleFields": "Missing required fields: name and policy.",
+		"invalidPolicy": "Invalid policy statement:",
+		"failedToCreateRole": "Failed to create role.",
+		"failedToDeleteRole": "Failed to delete role.",
+		"missingUpdateFields": "Missing fields to update: name or policies.",
+		"failedToUpdateRole": "Failed to update role."
+	},
+	"settings": {
+		"failedToRetrieve": "Failed to retrieve settings",
+		"failedToUpdate": "Failed to update settings"
+	},
+	"ingestion": {
+		"failedToCreate": "Failed to create ingestion source due to a connection error.",
+		"notFound": "Ingestion source not found",
+		"initialImportTriggered": "Initial import triggered successfully.",
+		"forceSyncTriggered": "Force sync triggered successfully."
+	},
+	"archivedEmail": {
+		"notFound": "Archived email not found"
+	},
+	"search": {
+		"keywordsRequired": "Keywords are required"
+	},
+	"storage": {
+		"filePathRequired": "File path is required",
+		"invalidFilePath": "Invalid file path",
+		"fileNotFound": "File not found",
+		"downloadError": "Error downloading file"
+	}
+}
diff --git a/packages/backend/src/locales/es/translation.json b/packages/backend/src/locales/es/translation.json
new file mode 100644
index 0000000..2222d95
--- /dev/null
+++ b/packages/backend/src/locales/es/translation.json
@@ -0,0 +1,55 @@
+{
+	"auth": {
+		"setup": {
+			"allFieldsRequired": "Se requieren correo electrónico, contraseña y nombre",
+			"alreadyCompleted": "La configuración ya se ha completado."
+		},
+		"login": {
+			"emailAndPasswordRequired": "Se requieren correo electrónico y contraseña",
+			"invalidCredentials": "Credenciales no válidas"
+		}
+	},
+	"errors": {
+		"internalServerError": "Ocurrió un error interno del servidor",
+		"demoMode": "Esta operación no está permitida en modo de demostración.",
+		"unauthorized": "No autorizado",
+		"unknown": "Ocurrió un error desconocido"
+	},
+	"user": {
+		"notFound": "Usuario no encontrado",
+		"cannotDeleteOnlyUser": "Está intentando eliminar el único usuario de la base de datos, esto no está permitido."
+	},
+	"iam": {
+		"failedToGetRoles": "Error al obtener los roles.",
+		"roleNotFound": "Rol no encontrado.",
+		"failedToGetRole": "Error al obtener el rol.",
+		"missingRoleFields": "Faltan campos obligatorios: nombre y política.",
+		"invalidPolicy": "Declaración de política no válida:",
+		"failedToCreateRole": "Error al crear el rol.",
+		"failedToDeleteRole": "Error al eliminar el rol.",
+		"missingUpdateFields": "Faltan campos para actualizar: nombre o políticas.",
+		"failedToUpdateRole": "Error al actualizar el rol."
+	},
+	"settings": {
+		"failedToRetrieve": "Error al recuperar la configuración",
+		"failedToUpdate": "Error al actualizar la configuración"
+	},
+	"ingestion": {
+		"failedToCreate": "Error al crear la fuente de ingesta debido a un error de conexión.",
+		"notFound": "Fuente de ingesta no encontrada",
+		"initialImportTriggered": "Importación inicial activada correctamente.",
+		"forceSyncTriggered": "Sincronización forzada activada correctamente."
+	},
+	"archivedEmail": {
+		"notFound": "Correo electrónico archivado no encontrado"
+	},
+	"search": {
+		"keywordsRequired": "Se requieren palabras clave"
+	},
+	"storage": {
+		"filePathRequired": "Se requiere la ruta del archivo",
+		"invalidFilePath": "Ruta de archivo no válida",
+		"fileNotFound": "Archivo no encontrado",
+		"downloadError": "Error al descargar el archivo"
+	}
+}
diff --git a/packages/backend/src/locales/et/translation.json b/packages/backend/src/locales/et/translation.json
new file mode 100644
index 0000000..f07b28a
--- /dev/null
+++ b/packages/backend/src/locales/et/translation.json
@@ -0,0 +1,55 @@
+{
+	"auth": {
+		"setup": {
+			"allFieldsRequired": "E-post, parool ja nimi on kohustuslikud",
+			"alreadyCompleted": "Seadistamine on juba lõpule viidud."
+		},
+		"login": {
+			"emailAndPasswordRequired": "E-post ja parool on kohustuslikud",
+			"invalidCredentials": "Valed sisselogimisandmed"
+		}
+	},
+	"errors": {
+		"internalServerError": "Ilmnes sisemine serveri viga",
+		"demoMode": "See toiming pole demo-režiimis lubatud.",
+		"unauthorized": "Volitamata",
+		"unknown": "Ilmnes tundmatu viga"
+	},
+	"user": {
+		"notFound": "Kasutajat ei leitud",
+		"cannotDeleteOnlyUser": "Püüate kustutada andmebaasi ainsat kasutajat, see pole lubatud."
+	},
+	"iam": {
+		"failedToGetRoles": "Rollide hankimine ebaõnnestus.",
+		"roleNotFound": "Rolli ei leitud.",
+		"failedToGetRole": "Rolli hankimine ebaõnnestus.",
+		"missingRoleFields": "Puuduvad kohustuslikud väljad: nimi ja poliitika.",
+		"invalidPolicy": "Kehtetu poliitika avaldus:",
+		"failedToCreateRole": "Rolli loomine ebaõnnestus.",
+		"failedToDeleteRole": "Rolli kustutamine ebaõnnestus.",
+		"missingUpdateFields": "Uuendatavad väljad puuduvad: nimi või poliitikad.",
+		"failedToUpdateRole": "Rolli värskendamine ebaõnnestus."
+	},
+	"settings": {
+		"failedToRetrieve": "Seadete toomine ebaõnnestus",
+		"failedToUpdate": "Seadete värskendamine ebaõnnestus"
+	},
+	"ingestion": {
+		"failedToCreate": "Söötmeallika loomine ebaõnnestus ühenduse vea tõttu.",
+		"notFound": "Söötmeallikat ei leitud",
+		"initialImportTriggered": "Esialgne import käivitati edukalt.",
+		"forceSyncTriggered": "Sunnitud sünkroonimine käivitati edukalt."
+	},
+	"archivedEmail": {
+		"notFound": "Arhiveeritud e-kirja ei leitud"
+	},
+	"search": {
+		"keywordsRequired": "Märksõnad on kohustuslikud"
+	},
+	"storage": {
+		"filePathRequired": "Faili tee on kohustuslik",
+		"invalidFilePath": "Kehtetu faili tee",
+		"fileNotFound": "Faili ei leitud",
+		"downloadError": "Faili allalaadimisel ilmnes viga"
+	}
+}
diff --git a/packages/backend/src/locales/fr/translation.json b/packages/backend/src/locales/fr/translation.json
new file mode 100644
index 0000000..bee47bc
--- /dev/null
+++ b/packages/backend/src/locales/fr/translation.json
@@ -0,0 +1,55 @@
+{
+	"auth": {
+		"setup": {
+			"allFieldsRequired": "E-mail, mot de passe et nom sont requis",
+			"alreadyCompleted": "La configuration est déjà terminée."
+		},
+		"login": {
+			"emailAndPasswordRequired": "E-mail et mot de passe sont requis",
+			"invalidCredentials": "Identifiants non valides"
+		}
+	},
+	"errors": {
+		"internalServerError": "Une erreur interne du serveur est survenue",
+		"demoMode": "Cette opération n'est pas autorisée en mode démo.",
+		"unauthorized": "Non autorisé",
+		"unknown": "Une erreur inconnue est survenue"
+	},
+	"user": {
+		"notFound": "Utilisateur non trouvé",
+		"cannotDeleteOnlyUser": "Vous essayez de supprimer le seul utilisateur de la base de données, ce n'est pas autorisé."
+	},
+	"iam": {
+		"failedToGetRoles": "Échec de la récupération des rôles.",
+		"roleNotFound": "Rôle non trouvé.",
+		"failedToGetRole": "Échec de la récupération du rôle.",
+		"missingRoleFields": "Champs obligatoires manquants : nom et politique.",
+		"invalidPolicy": "Déclaration de politique non valide :",
+		"failedToCreateRole": "Échec de la création du rôle.",
+		"failedToDeleteRole": "Échec de la suppression du rôle.",
+		"missingUpdateFields": "Champs à mettre à jour manquants : nom ou politiques.",
+		"failedToUpdateRole": "Échec de la mise à jour du rôle."
+	},
+	"settings": {
+		"failedToRetrieve": "Échec de la récupération des paramètres",
+		"failedToUpdate": "Échec de la mise à jour des paramètres"
+	},
+	"ingestion": {
+		"failedToCreate": "Échec de la création de la source d'ingestion en raison d'une erreur de connexion.",
+		"notFound": "Source d'ingestion non trouvée",
+		"initialImportTriggered": "Importation initiale déclenchée avec succès.",
+		"forceSyncTriggered": "Synchronisation forcée déclenchée avec succès."
+	},
+	"archivedEmail": {
+		"notFound": "E-mail archivé non trouvé"
+	},
+	"search": {
+		"keywordsRequired": "Mots-clés requis"
+	},
+	"storage": {
+		"filePathRequired": "Chemin du fichier requis",
+		"invalidFilePath": "Chemin de fichier non valide",
+		"fileNotFound": "Fichier non trouvé",
+		"downloadError": "Erreur lors du téléchargement du fichier"
+	}
+}
diff --git a/packages/backend/src/locales/it/translation.json b/packages/backend/src/locales/it/translation.json
new file mode 100644
index 0000000..d70a798
--- /dev/null
+++ b/packages/backend/src/locales/it/translation.json
@@ -0,0 +1,55 @@
+{
+	"auth": {
+		"setup": {
+			"allFieldsRequired": "Email, password e nome sono obbligatori",
+			"alreadyCompleted": "La configurazione è già stata completata."
+		},
+		"login": {
+			"emailAndPasswordRequired": "Email e password sono obbligatori",
+			"invalidCredentials": "Credenziali non valide"
+		}
+	},
+	"errors": {
+		"internalServerError": "Si è verificato un errore interno del server",
+		"demoMode": "Questa operazione non è consentita in modalità demo.",
+		"unauthorized": "Non autorizzato",
+		"unknown": "Si è verificato un errore sconosciuto"
+	},
+	"user": {
+		"notFound": "Utente non trovato",
+		"cannotDeleteOnlyUser": "Stai tentando di eliminare l'unico utente nel database, ciò non è consentito."
+	},
+	"iam": {
+		"failedToGetRoles": "Impossibile ottenere i ruoli.",
+		"roleNotFound": "Ruolo non trovato.",
+		"failedToGetRole": "Impossibile ottenere il ruolo.",
+		"missingRoleFields": "Campi obbligatori mancanti: nome e politica.",
+		"invalidPolicy": "Dichiarazione di politica non valida:",
+		"failedToCreateRole": "Impossibile creare il ruolo.",
+		"failedToDeleteRole": "Impossibile eliminare il ruolo.",
+		"missingUpdateFields": "Campi da aggiornare mancanti: nome o politiche.",
+		"failedToUpdateRole": "Impossibile aggiornare il ruolo."
+	},
+	"settings": {
+		"failedToRetrieve": "Impossibile recuperare le impostazioni",
+		"failedToUpdate": "Impossibile aggiornare le impostazioni"
+	},
+	"ingestion": {
+		"failedToCreate": "Impossibile creare l'origine di ingestione a causa di un errore di connessione.",
+		"notFound": "Origine di ingestione non trovata",
+		"initialImportTriggered": "Importazione iniziale attivata con successo.",
+		"forceSyncTriggered": "Sincronizzazione forzata attivata con successo."
+	},
+	"archivedEmail": {
+		"notFound": "Email archiviata non trovata"
+	},
+	"search": {
+		"keywordsRequired": "Le parole chiave sono obbligatorie"
+	},
+	"storage": {
+		"filePathRequired": "Il percorso del file è obbligatorio",
+		"invalidFilePath": "Percorso del file non valido",
+		"fileNotFound": "File non trovato",
+		"downloadError": "Errore durante il download del file"
+	}
+}
diff --git a/packages/backend/src/locales/ja/translation.json b/packages/backend/src/locales/ja/translation.json
new file mode 100644
index 0000000..ceebeba
--- /dev/null
+++ b/packages/backend/src/locales/ja/translation.json
@@ -0,0 +1,55 @@
+{
+	"auth": {
+		"setup": {
+			"allFieldsRequired": "メールアドレス、パスワード、氏名が必要です",
+			"alreadyCompleted": "セットアップは既に完了しています。"
+		},
+		"login": {
+			"emailAndPasswordRequired": "メールアドレスとパスワードが必要です",
+			"invalidCredentials": "認証情報が無効です"
+		}
+	},
+	"errors": {
+		"internalServerError": "内部サーバーエラーが発生しました",
+		"demoMode": "この操作はデモモードでは許可されていません。",
+		"unauthorized": "不正なアクセスです",
+		"unknown": "不明なエラーが発生しました"
+	},
+	"user": {
+		"notFound": "ユーザーが見つかりません",
+		"cannotDeleteOnlyUser": "データベース内の唯一のユーザーを削除しようとしていますが、これは許可されていません。"
+	},
+	"iam": {
+		"failedToGetRoles": "ロールの取得に失敗しました。",
+		"roleNotFound": "ロールが見つかりません。",
+		"failedToGetRole": "ロールの取得に失敗しました。",
+		"missingRoleFields": "必須フィールドがありません：名前とポリシー。",
+		"invalidPolicy": "無効なポリシーステートメント:",
+		"failedToCreateRole": "ロールの作成に失敗しました。",
+		"failedToDeleteRole": "ロールの削除に失敗しました。",
+		"missingUpdateFields": "更新するフィールドがありません：名前またはポリシー。",
+		"failedToUpdateRole": "ロールの更新に失敗しました。"
+	},
+	"settings": {
+		"failedToRetrieve": "設定の取得に失敗しました",
+		"failedToUpdate": "設定の更新に失敗しました"
+	},
+	"ingestion": {
+		"failedToCreate": "接続エラーのため、取り込みソースの作成に失敗しました。",
+		"notFound": "取り込みソースが見つかりません",
+		"initialImportTriggered": "初期インポートが正常にトリガーされました。",
+		"forceSyncTriggered": "強制同期が正常にトリガーされました。"
+	},
+	"archivedEmail": {
+		"notFound": "アーカイブされたメールが見つかりません"
+	},
+	"search": {
+		"keywordsRequired": "キーワードが必要です"
+	},
+	"storage": {
+		"filePathRequired": "ファイルパスが必要です",
+		"invalidFilePath": "無効なファイルパスです",
+		"fileNotFound": "ファイルが見つかりません",
+		"downloadError": "ファイルのダウンロード中にエラーが発生しました"
+	}
+}
diff --git a/packages/backend/src/locales/nl/translation.json b/packages/backend/src/locales/nl/translation.json
new file mode 100644
index 0000000..d5a41f4
--- /dev/null
+++ b/packages/backend/src/locales/nl/translation.json
@@ -0,0 +1,55 @@
+{
+	"auth": {
+		"setup": {
+			"allFieldsRequired": "E-mail, wachtwoord en naam zijn verplicht",
+			"alreadyCompleted": "De installatie is al voltooid."
+		},
+		"login": {
+			"emailAndPasswordRequired": "E-mail en wachtwoord zijn verplicht",
+			"invalidCredentials": "Ongeldige inloggegevens"
+		}
+	},
+	"errors": {
+		"internalServerError": "Er is een interne serverfout opgetreden",
+		"demoMode": "Deze bewerking is niet toegestaan in de demomodus.",
+		"unauthorized": "Ongeautoriseerd",
+		"unknown": "Er is een onbekende fout opgetreden"
+	},
+	"user": {
+		"notFound": "Gebruiker niet gevonden",
+		"cannotDeleteOnlyUser": "U probeert de enige gebruiker in de database te verwijderen, dit is niet toegestaan."
+	},
+	"iam": {
+		"failedToGetRoles": "Rollen ophalen mislukt.",
+		"roleNotFound": "Rol niet gevonden.",
+		"failedToGetRole": "Rol ophalen mislukt.",
+		"missingRoleFields": "Verplichte velden ontbreken: naam en beleid.",
+		"invalidPolicy": "Ongeldige beleidsverklaring:",
+		"failedToCreateRole": "Rol aanmaken mislukt.",
+		"failedToDeleteRole": "Rol verwijderen mislukt.",
+		"missingUpdateFields": "Te updaten velden ontbreken: naam of beleid.",
+		"failedToUpdateRole": "Rol bijwerken mislukt."
+	},
+	"settings": {
+		"failedToRetrieve": "Instellingen ophalen mislukt",
+		"failedToUpdate": "Instellingen bijwerken mislukt"
+	},
+	"ingestion": {
+		"failedToCreate": "Aanmaken van de opnamebron mislukt vanwege een verbindingsfout.",
+		"notFound": "Opnamebron niet gevonden",
+		"initialImportTriggered": "Initiële import succesvol gestart.",
+		"forceSyncTriggered": "Geforceerde synchronisatie succesvol gestart."
+	},
+	"archivedEmail": {
+		"notFound": "Gearchiveerde e-mail niet gevonden"
+	},
+	"search": {
+		"keywordsRequired": "Trefwoorden zijn verplicht"
+	},
+	"storage": {
+		"filePathRequired": "Bestandspad is verplicht",
+		"invalidFilePath": "Ongeldig bestandspad",
+		"fileNotFound": "Bestand niet gevonden",
+		"downloadError": "Fout bij het downloaden van het bestand"
+	}
+}
diff --git a/packages/backend/src/locales/pt/translation.json b/packages/backend/src/locales/pt/translation.json
new file mode 100644
index 0000000..b85dea7
--- /dev/null
+++ b/packages/backend/src/locales/pt/translation.json
@@ -0,0 +1,55 @@
+{
+	"auth": {
+		"setup": {
+			"allFieldsRequired": "E-mail, senha e nome são obrigatórios",
+			"alreadyCompleted": "A configuração já foi concluída."
+		},
+		"login": {
+			"emailAndPasswordRequired": "E-mail and senha são obrigatórios",
+			"invalidCredentials": "Credenciais inválidas"
+		}
+	},
+	"errors": {
+		"internalServerError": "Ocorreu um erro interno do servidor",
+		"demoMode": "Esta operação não é permitida no modo de demonstração.",
+		"unauthorized": "Não autorizado",
+		"unknown": "Ocorreu um erro desconhecido"
+	},
+	"user": {
+		"notFound": "Usuário não encontrado",
+		"cannotDeleteOnlyUser": "Você está tentando excluir o único usuário no banco de dados, isso não é permitido."
+	},
+	"iam": {
+		"failedToGetRoles": "Falha ao obter as funções.",
+		"roleNotFound": "Função não encontrada.",
+		"failedToGetRole": "Falha ao obter a função.",
+		"missingRoleFields": "Campos obrigatórios ausentes: nome e política.",
+		"invalidPolicy": "Declaração de política inválida:",
+		"failedToCreateRole": "Falha ao criar a função.",
+		"failedToDeleteRole": "Falha ao excluir a função.",
+		"missingUpdateFields": "Campos ausentes para atualizar: nome ou políticas.",
+		"failedToUpdateRole": "Falha ao atualizar a função."
+	},
+	"settings": {
+		"failedToRetrieve": "Falha ao recuperar as configurações",
+		"failedToUpdate": "Falha ao atualizar as configurações"
+	},
+	"ingestion": {
+		"failedToCreate": "Falha ao criar a fonte de ingestão devido a um erro de conexão.",
+		"notFound": "Fonte de ingestão não encontrada",
+		"initialImportTriggered": "Importação inicial acionada com sucesso.",
+		"forceSyncTriggered": "Sincronização forçada acionada com sucesso."
+	},
+	"archivedEmail": {
+		"notFound": "E-mail arquivado não encontrado"
+	},
+	"search": {
+		"keywordsRequired": "Palavras-chave são obrigatórias"
+	},
+	"storage": {
+		"filePathRequired": "O caminho do arquivo é obrigatório",
+		"invalidFilePath": "Caminho de arquivo inválido",
+		"fileNotFound": "Arquivo não encontrado",
+		"downloadError": "Erro ao baixar o arquivo"
+	}
+}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 40d3da9..3a2376c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -96,6 +96,15 @@ importers:
       googleapis:
         specifier: ^152.0.0
         version: 152.0.0
+      i18next:
+        specifier: ^25.4.2
+        version: 25.4.2(typescript@5.8.3)
+      i18next-fs-backend:
+        specifier: ^2.6.0
+        version: 2.6.0
+      i18next-http-middleware:
+        specifier: ^3.8.0
+        version: 3.8.0
       imapflow:
         specifier: ^1.0.191
         version: 1.0.191
@@ -3052,6 +3061,20 @@ packages:
   humanize-ms@1.2.1:
     resolution: {integrity: sha512-Fl70vYtsAFb/C06PTS9dZBo7ihau+Tu/DNCk/OyHhea07S+aeMWpFFkUaXRa8fI+ScZbEI8dfSxwY7gxZ9SAVQ==}
 
+  i18next-fs-backend@2.6.0:
+    resolution: {integrity: sha512-3ZlhNoF9yxnM8pa8bWp5120/Ob6t4lVl1l/tbLmkml/ei3ud8IWySCHt2lrY5xWRlSU5D9IV2sm5bEbGuTqwTw==}
+
+  i18next-http-middleware@3.8.0:
+    resolution: {integrity: sha512-G3DpT/ibwOx6BCI5A2xUmZ2ybUDUrI6emCdEE7AX9TKvz+WzA6peuyv0BxC8kIrJHtrdnmUWwk4rDN9nxWvsFg==}
+
+  i18next@25.4.2:
+    resolution: {integrity: sha512-gD4T25a6ovNXsfXY1TwHXXXLnD/K2t99jyYMCSimSCBnBRJVQr5j+VAaU83RJCPzrTGhVQ6dqIga66xO2rtd5g==}
+    peerDependencies:
+      typescript: ^5
+    peerDependenciesMeta:
+      typescript:
+        optional: true
+
   iconv-lite@0.4.24:
     resolution: {integrity: sha512-v3MXnZAcvnywkTUEZomIActle7RXXeedOR31wwl7VlyoXO4Qi9arvSenNQWne1TcRwhCL1HwLI21bEqdpj8/rA==}
     engines: {node: '>=0.10.0'}
@@ -7931,6 +7954,16 @@ snapshots:
       ms: 2.1.3
     optional: true
 
+  i18next-fs-backend@2.6.0: {}
+
+  i18next-http-middleware@3.8.0: {}
+
+  i18next@25.4.2(typescript@5.8.3):
+    dependencies:
+      '@babel/runtime': 7.27.6
+    optionalDependencies:
+      typescript: 5.8.3
+
   iconv-lite@0.4.24:
     dependencies:
       safer-buffer: 2.1.2