diff --git a/apps/backend/package.json b/apps/backend/package.json
index b31c411..d3fa778 100644
--- a/apps/backend/package.json
+++ b/apps/backend/package.json
@@ -27,7 +27,10 @@
     "@nestjs/core": "^11.0.1",
     "@nestjs/platform-express": "^11.0.1",
     "dotenv": "^17.2.1",
+    "i18next": "^25.3.2",
+    "i18next-fs-backend": "^2.6.0",
     "kysely": "^0.28.3",
+    "nodemailer": "^7.0.5",
     "pg": "^8.16.3",
     "reflect-metadata": "^0.2.2",
     "rxjs": "^7.8.1",
@@ -44,6 +47,7 @@
     "@types/express": "^5.0.0",
     "@types/jest": "^29.5.14",
     "@types/node": "^22.10.7",
+    "@types/nodemailer": "^6.4.17",
     "@types/pg": "^8.15.4",
     "@types/supertest": "^6.0.2",
     "eslint": "^9.18.0",
diff --git a/apps/backend/src/app-error.filter.spec.ts b/apps/backend/src/app-error.filter.spec.ts
new file mode 100644
index 0000000..5c3b9a1
--- /dev/null
+++ b/apps/backend/src/app-error.filter.spec.ts
@@ -0,0 +1,7 @@
+import { AppErrorFilter } from './app-error.filter';
+
+describe('AppErrorFilter', () => {
+  it('should be defined', () => {
+    expect(new AppErrorFilter()).toBeDefined();
+  });
+});
diff --git a/apps/backend/src/app-error.filter.ts b/apps/backend/src/app-error.filter.ts
new file mode 100644
index 0000000..500f4ef
--- /dev/null
+++ b/apps/backend/src/app-error.filter.ts
@@ -0,0 +1,13 @@
+import { Catch, ExceptionFilter, HttpException } from '@nestjs/common';
+import { AppError } from './lib/app-error';
+
+@Catch(AppError)
+export class AppErrorFilter<T extends AppError> implements ExceptionFilter {
+  catch(exception: T) {
+    if (exception.status) {
+      throw new HttpException(exception.message, exception.status, {
+        cause: exception,
+      });
+    }
+  }
+}
diff --git a/apps/backend/src/app.module.ts b/apps/backend/src/app.module.ts
index 5aa3c94..223f156 100644
--- a/apps/backend/src/app.module.ts
+++ b/apps/backend/src/app.module.ts
@@ -1,13 +1,25 @@
 import { Module } from '@nestjs/common';
 import { AuthController } from './app/auth/auth.controller';
-import { DatabaseService } from './database/database.service';
+import { DatabaseService } from './services/database/database.service';
 import { AuthService } from './app/auth/auth.service';
-import { UserRegistryService } from './app/users/user-registry.service';
-import { EnvService } from './env/env.service';
+import { UsersService } from './app/users/users.service';
+import { EnvService } from './services/env/env.service';
+import { UsersRegistry } from './app/users/users-registry';
+import { UsersController } from './app/users/users.controller';
+import { MailerService } from './services/mailer/mailer.service';
+import { localizationServiceProvider } from './services/localization/localization.service';
 
 @Module({
   imports: [],
-  controllers: [AuthController],
-  providers: [DatabaseService, AuthService, UserRegistryService, EnvService],
+  controllers: [AuthController, UsersController],
+  providers: [
+    DatabaseService,
+    AuthService,
+    UsersService,
+    EnvService,
+    UsersRegistry,
+    MailerService,
+    localizationServiceProvider,
+  ],
 })
 export class AppModule {}
diff --git a/apps/backend/src/app/auth/auth.controller.ts b/apps/backend/src/app/auth/auth.controller.ts
index 6cae994..8db7df3 100644
--- a/apps/backend/src/app/auth/auth.controller.ts
+++ b/apps/backend/src/app/auth/auth.controller.ts
@@ -5,9 +5,7 @@ import { AuthService } from './auth.service';
 export class AuthController {
   constructor(private authService: AuthService) {}
 
-  // eslint-disable-next-line @typescript-eslint/no-misused-promises
   @Post('credentials')
-  // eslint-disable-next-line @typescript-eslint/require-await
   async postCredentials() {
     return this.authService.verifyCredentials();
   }
diff --git a/apps/backend/src/app/auth/auth.service.ts b/apps/backend/src/app/auth/auth.service.ts
index 21e5365..0702160 100644
--- a/apps/backend/src/app/auth/auth.service.ts
+++ b/apps/backend/src/app/auth/auth.service.ts
@@ -1,9 +1,9 @@
 import { Injectable, UnauthorizedException } from '@nestjs/common';
-import { UserRegistryService } from '../users/user-registry.service';
+import { UsersRegistry } from '../users/users-registry';
 
 @Injectable()
 export class AuthService {
-  constructor(private userRegistry: UserRegistryService) {}
+  constructor(private userRegistry: UsersRegistry) {}
 
   async verifyCredentials() {
     const isValidCredential = await this.userRegistry.existsEmailPassword(
diff --git a/apps/backend/src/app/users/user-registry.service.ts b/apps/backend/src/app/users/user-registry.service.ts
deleted file mode 100644
index 88aa160..0000000
--- a/apps/backend/src/app/users/user-registry.service.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-import { Injectable } from '@nestjs/common';
-import { DatabaseService } from '../../database/database.service';
-import { isDefined } from '@my-monorepo/common';
-
-@Injectable()
-export class UserRegistryService {
-  constructor(private databaseService: DatabaseService) {}
-
-  async existsEmailPassword(email: string, hashedPassword: string) {
-    const id = await this.databaseService.database
-      .selectFrom('users')
-      .select('id')
-      .where((eb) => eb('email', '=', email).and('hash', '=', hashedPassword))
-      .executeTakeFirst();
-
-    return isDefined(id);
-  }
-}
diff --git a/apps/backend/src/app/users/users-error.ts b/apps/backend/src/app/users/users-error.ts
new file mode 100644
index 0000000..b670d77
--- /dev/null
+++ b/apps/backend/src/app/users/users-error.ts
@@ -0,0 +1,11 @@
+import { AppError } from '../../lib/app-error';
+import { HttpStatus } from '@nestjs/common';
+
+export class UserEmailAlreadyExistError extends AppError {
+  constructor() {
+    super({
+      message: 'User email already exists',
+      status: HttpStatus.BAD_REQUEST,
+    });
+  }
+}
diff --git a/apps/backend/src/app/users/users-registry.spec.ts b/apps/backend/src/app/users/users-registry.spec.ts
new file mode 100644
index 0000000..5b29aa5
--- /dev/null
+++ b/apps/backend/src/app/users/users-registry.spec.ts
@@ -0,0 +1,18 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { UsersRegistry } from './users-registry';
+
+describe('UsersRegistry', () => {
+  let provider: UsersRegistry;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [UsersRegistry],
+    }).compile();
+
+    provider = module.get<UsersRegistry>(UsersRegistry);
+  });
+
+  it('should be defined', () => {
+    expect(provider).toBeDefined();
+  });
+});
diff --git a/apps/backend/src/app/users/users-registry.ts b/apps/backend/src/app/users/users-registry.ts
new file mode 100644
index 0000000..6d4dd12
--- /dev/null
+++ b/apps/backend/src/app/users/users-registry.ts
@@ -0,0 +1,67 @@
+import { Injectable } from '@nestjs/common';
+import { DatabaseService } from '../../services/database/database.service';
+import { CreateUser, isDefined, Result, User } from '@my-monorepo/common';
+import { UserEmailAlreadyExistError } from './users-error';
+
+@Injectable()
+export class UsersRegistry {
+  get database() {
+    return this.databaseService.database;
+  }
+
+  constructor(private databaseService: DatabaseService) {}
+
+  async existsEmailPassword(email: string, hashedPassword: string) {
+    const id = await this.database
+      .selectFrom('users')
+      .select('id')
+      .where((eb) => eb('email', '=', email).and('hash', '=', hashedPassword))
+      .executeTakeFirst();
+
+    return isDefined(id);
+  }
+
+  async addUser(
+    newUser: CreateUser,
+  ): Promise<Result<User, UserEmailAlreadyExistError>> {
+    const rowWithEmail = await this.database
+      .selectFrom('users')
+      .select('id')
+      .where('email', '=', newUser.email)
+      .executeTakeFirst();
+
+    if (isDefined(rowWithEmail)) {
+      return Result.error(new UserEmailAlreadyExistError());
+    }
+
+    const userQuery = this.database
+      .insertInto('users')
+      .values({
+        email: newUser.email,
+        first_name: newUser.firstName,
+        last_name: newUser.lastName,
+      })
+      .returning([
+        'id',
+        'email',
+        'created_at',
+        'updated_at',
+        'deleted_at',
+        'first_name',
+        'last_name',
+      ]);
+    const user = await userQuery.executeTakeFirst();
+    if (!isDefined(user)) {
+      return Result.error(new UserEmailAlreadyExistError());
+    }
+    return Result.success<User>({
+      id: user.id,
+      firstName: user.first_name,
+      lastName: user.last_name,
+      email: user.email,
+      createdAt: user.created_at,
+      updatedAt: user.updated_at,
+      deletedAt: user.deleted_at ?? undefined,
+    });
+  }
+}
diff --git a/apps/backend/src/app/users/users.controller.spec.ts b/apps/backend/src/app/users/users.controller.spec.ts
new file mode 100644
index 0000000..3e27c39
--- /dev/null
+++ b/apps/backend/src/app/users/users.controller.spec.ts
@@ -0,0 +1,18 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { UsersController } from './users.controller';
+
+describe('UsersController', () => {
+  let controller: UsersController;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      controllers: [UsersController],
+    }).compile();
+
+    controller = module.get<UsersController>(UsersController);
+  });
+
+  it('should be defined', () => {
+    expect(controller).toBeDefined();
+  });
+});
diff --git a/apps/backend/src/app/users/users.controller.ts b/apps/backend/src/app/users/users.controller.ts
new file mode 100644
index 0000000..6035100
--- /dev/null
+++ b/apps/backend/src/app/users/users.controller.ts
@@ -0,0 +1,15 @@
+import { CreateUser, createUserParser } from '@my-monorepo/common';
+import { Body, Controller, Post, UsePipes } from '@nestjs/common';
+import { ZodValidationPipe } from '../../lib/nestjs/zod-validation/zod-validation.pipe';
+import { UsersService } from './users.service';
+
+@Controller('users')
+export class UsersController {
+  constructor(private userService: UsersService) {}
+
+  @Post()
+  @UsePipes(new ZodValidationPipe(createUserParser))
+  async createUser(@Body() newUser: CreateUser) {
+    return this.userService.createUser(newUser);
+  }
+}
diff --git a/apps/backend/src/app/users/users.service.spec.ts b/apps/backend/src/app/users/users.service.spec.ts
new file mode 100644
index 0000000..62815ba
--- /dev/null
+++ b/apps/backend/src/app/users/users.service.spec.ts
@@ -0,0 +1,18 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { UsersService } from './users.service';
+
+describe('UsersService', () => {
+  let service: UsersService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [UsersService],
+    }).compile();
+
+    service = module.get<UsersService>(UsersService);
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+});
diff --git a/apps/backend/src/app/users/users.service.ts b/apps/backend/src/app/users/users.service.ts
new file mode 100644
index 0000000..87595e5
--- /dev/null
+++ b/apps/backend/src/app/users/users.service.ts
@@ -0,0 +1,31 @@
+import { CreateUser } from '@my-monorepo/common';
+import { Inject, Injectable } from '@nestjs/common';
+import { MailerService } from '../../services/mailer/mailer.service';
+import { UsersRegistry } from './users-registry';
+import {
+  LOCALIZATION_SERVICE,
+  LocalizationService,
+} from '../../services/localization/localization.service';
+
+@Injectable()
+export class UsersService {
+  constructor(
+    private userRegistry: UsersRegistry,
+    private mailerService: MailerService,
+    @Inject(LOCALIZATION_SERVICE)
+    private localizationService: LocalizationService,
+  ) {}
+
+  async createUser(newUser: CreateUser): Promise<void> {
+    // FIXME : return result once auth is done
+    await this.userRegistry.addUser(newUser);
+    this.localizationService.translate('mail.create-user.title');
+    void this.mailerService.sendEmail({
+      toAdresses: [newUser.email],
+      subject: 'Your account has been created!',
+      html: `<h1>Welcome to COWSI</h1>
+        <p>Your account has been successfully created</p>
+      `,
+    });
+  }
+}
diff --git a/apps/backend/src/assets/i18n/en.json b/apps/backend/src/assets/i18n/en.json
new file mode 100644
index 0000000..09b7159
--- /dev/null
+++ b/apps/backend/src/assets/i18n/en.json
@@ -0,0 +1,4 @@
+{
+  "mail.create-user.title": "Welcome to Cowsi",
+  "mail.create-user.body-html": "<h1>Welcome to Cowsi<h1>"
+}
\ No newline at end of file
diff --git a/apps/backend/src/assets/i18n/fr.json b/apps/backend/src/assets/i18n/fr.json
new file mode 100644
index 0000000..48cf347
--- /dev/null
+++ b/apps/backend/src/assets/i18n/fr.json
@@ -0,0 +1,4 @@
+{
+  "mail.create-user.title": "Bienvenue sur Cowsi",
+  "mail.create-user.body-html": "<h1>Bienvenue sur Cowsi<h1>"
+}
\ No newline at end of file
diff --git a/apps/backend/src/env/env.service.ts b/apps/backend/src/env/env.service.ts
deleted file mode 100644
index 4b09fd0..0000000
--- a/apps/backend/src/env/env.service.ts
+++ /dev/null
@@ -1,27 +0,0 @@
-import { Injectable } from '@nestjs/common';
-import z from 'zod';
-import * as dotenv from 'dotenv';
-
-const envParser = z.object({
-  DATABASE: z.string(),
-  DATABASE_USER: z.string(),
-  DATABASE_PASSWORD: z.string(),
-  DATABASE_HOST: z.string(),
-  DATABASE_PORT: z.coerce.number(),
-});
-
-export type EnvConfig = Readonly<z.infer<typeof envParser>>;
-
-@Injectable()
-export class EnvService {
-  readonly config: EnvConfig;
-
-  constructor() {
-    console.log('paul-debug', dotenv);
-    const res = dotenv.config();
-    if (res.error) {
-      throw res.error;
-    }
-    this.config = envParser.parse(res.parsed);
-  }
-}
diff --git a/apps/backend/src/lib/app-error.ts b/apps/backend/src/lib/app-error.ts
new file mode 100644
index 0000000..6676bb7
--- /dev/null
+++ b/apps/backend/src/lib/app-error.ts
@@ -0,0 +1,14 @@
+import { HttpStatus } from '@nestjs/common';
+
+export class AppError extends Error {
+  public readonly status?: HttpStatus = 500;
+
+  constructor(opts: {
+    message: string;
+    status?: HttpStatus;
+    options?: ErrorOptions;
+  }) {
+    super(opts.message, opts.options);
+    this.status = opts.status;
+  }
+}
diff --git a/apps/backend/src/lib/nestjs/zod-validation/zod-validation.pipe.spec.ts b/apps/backend/src/lib/nestjs/zod-validation/zod-validation.pipe.spec.ts
new file mode 100644
index 0000000..1b0803e
--- /dev/null
+++ b/apps/backend/src/lib/nestjs/zod-validation/zod-validation.pipe.spec.ts
@@ -0,0 +1,7 @@
+import { ZodValidationPipe } from './zod-validation.pipe';
+
+describe('ZodValidationPipe', () => {
+  it('should be defined', () => {
+    expect(new ZodValidationPipe()).toBeDefined();
+  });
+});
diff --git a/apps/backend/src/lib/nestjs/zod-validation/zod-validation.pipe.ts b/apps/backend/src/lib/nestjs/zod-validation/zod-validation.pipe.ts
new file mode 100644
index 0000000..aebd3d9
--- /dev/null
+++ b/apps/backend/src/lib/nestjs/zod-validation/zod-validation.pipe.ts
@@ -0,0 +1,20 @@
+import { PipeTransform, BadRequestException } from '@nestjs/common';
+import { ZodSchema } from 'zod';
+
+export class ZodValidationPipe<Z extends ZodSchema> implements PipeTransform {
+  constructor(private schema: Z) {}
+
+  transform(value: unknown) {
+    const parsedValue = this.schema.safeParse(value);
+    if (!parsedValue.success) {
+      const invalidFields = parsedValue.error.errors
+        .map((v) => v.path.join('.'))
+        .join(', ');
+      throw new BadRequestException(
+        `Validation failed for fields : ${invalidFields}`,
+      );
+    }
+    // FIXME improve this typing if possible
+    return parsedValue.data as unknown;
+  }
+}
diff --git a/apps/backend/src/main.ts b/apps/backend/src/main.ts
index f76bc8d..d5c787b 100644
--- a/apps/backend/src/main.ts
+++ b/apps/backend/src/main.ts
@@ -1,8 +1,10 @@
 import { NestFactory } from '@nestjs/core';
 import { AppModule } from './app.module';
+import { AppErrorFilter } from './app-error.filter';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
+  app.useGlobalFilters(new AppErrorFilter());
   await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();
diff --git a/apps/backend/src/database/database.service.spec.ts b/apps/backend/src/services/database/database.service.spec.ts
similarity index 100%
rename from apps/backend/src/database/database.service.spec.ts
rename to apps/backend/src/services/database/database.service.spec.ts
diff --git a/apps/backend/src/database/database.service.ts b/apps/backend/src/services/database/database.service.ts
similarity index 73%
rename from apps/backend/src/database/database.service.ts
rename to apps/backend/src/services/database/database.service.ts
index ec6b38c..67dbb8f 100644
--- a/apps/backend/src/database/database.service.ts
+++ b/apps/backend/src/services/database/database.service.ts
@@ -2,7 +2,7 @@ import { Injectable } from '@nestjs/common';
 
 import { Pool } from 'pg';
 import { Kysely, PostgresDialect } from 'kysely';
-import { DB } from './db';
+import { DB } from '../../database/db';
 import { EnvService } from '../env/env.service';
 
 @Injectable()
@@ -10,14 +10,14 @@ export class DatabaseService {
   database: Kysely<DB>;
 
   constructor(envService: EnvService) {
-    const config = envService.config;
+    const config = envService.config.database;
     const dialect = new PostgresDialect({
       pool: new Pool({
-        database: config.DATABASE,
-        host: config.DATABASE_HOST,
-        user: config.DATABASE_USER,
-        password: config.DATABASE_PASSWORD,
-        port: config.DATABASE_PORT,
+        database: config.name,
+        host: config.host,
+        user: config.user,
+        password: config.password,
+        port: config.port,
         max: 10,
       }),
     });
diff --git a/apps/backend/src/env/env.service.spec.ts b/apps/backend/src/services/env/env.service.spec.ts
similarity index 100%
rename from apps/backend/src/env/env.service.spec.ts
rename to apps/backend/src/services/env/env.service.spec.ts
diff --git a/apps/backend/src/services/env/env.service.ts b/apps/backend/src/services/env/env.service.ts
new file mode 100644
index 0000000..71c51f7
--- /dev/null
+++ b/apps/backend/src/services/env/env.service.ts
@@ -0,0 +1,46 @@
+import { Injectable } from '@nestjs/common';
+import z from 'zod';
+import * as dotenv from 'dotenv';
+
+const envParser = z
+  .object({
+    DATABASE: z.string(),
+    DATABASE_USER: z.string(),
+    DATABASE_PASSWORD: z.string(),
+    DATABASE_HOST: z.string(),
+    DATABASE_PORT: z.coerce.number(),
+    MAIL_HOST: z.string(),
+    MAIL_PORT: z.coerce.number(),
+    MAIL_USER: z.string().email(),
+    MAIL_PASSWORD: z.string(),
+  })
+  .transform((parsed) => ({
+    database: {
+      name: parsed.DATABASE,
+      user: parsed.DATABASE_USER,
+      password: parsed.DATABASE_PASSWORD,
+      host: parsed.DATABASE_HOST,
+      port: parsed.DATABASE_PORT,
+    },
+    mail: {
+      host: parsed.MAIL_HOST,
+      port: parsed.MAIL_PORT,
+      user: parsed.MAIL_USER,
+      password: parsed.MAIL_PASSWORD,
+    },
+  }));
+
+export type EnvConfig = Readonly<z.infer<typeof envParser>>;
+
+@Injectable()
+export class EnvService {
+  readonly config: EnvConfig;
+
+  constructor() {
+    const res = dotenv.config();
+    if (res.error) {
+      throw res.error;
+    }
+    this.config = envParser.parse(res.parsed);
+  }
+}
diff --git a/apps/backend/src/app/users/user-registry.service.spec.ts b/apps/backend/src/services/localization/localization.service.spec.ts
similarity index 51%
rename from apps/backend/src/app/users/user-registry.service.spec.ts
rename to apps/backend/src/services/localization/localization.service.spec.ts
index d18db6e..840a350 100644
--- a/apps/backend/src/app/users/user-registry.service.spec.ts
+++ b/apps/backend/src/services/localization/localization.service.spec.ts
@@ -1,15 +1,15 @@
 import { Test, TestingModule } from '@nestjs/testing';
-import { UserRegistryService } from './user-registry.service';
+import { LocalizationService } from './localization.service';
 
-describe('UserRegistryService', () => {
-  let service: UserRegistryService;
+describe('LocalizationService', () => {
+  let service: LocalizationService;
 
   beforeEach(async () => {
     const module: TestingModule = await Test.createTestingModule({
-      providers: [UserRegistryService],
+      providers: [LocalizationService],
     }).compile();
 
-    service = module.get<UserRegistryService>(UserRegistryService);
+    service = module.get<LocalizationService>(LocalizationService);
   });
 
   it('should be defined', () => {
diff --git a/apps/backend/src/services/localization/localization.service.ts b/apps/backend/src/services/localization/localization.service.ts
new file mode 100644
index 0000000..bcd6115
--- /dev/null
+++ b/apps/backend/src/services/localization/localization.service.ts
@@ -0,0 +1,34 @@
+import { isSupportedLang } from '@my-monorepo/common';
+import { FactoryProvider, Scope } from '@nestjs/common';
+import { Request } from 'express';
+import * as i18next from 'i18next';
+import * as i18nextBackend from 'i18next-fs-backend';
+
+export const LOCALIZATION_SERVICE = 'LOCALIZATION_SERVICE';
+
+export const localizationServiceProvider: FactoryProvider = {
+  provide: LOCALIZATION_SERVICE,
+  scope: Scope.REQUEST,
+  useFactory: async (req: Request) => {
+    const instance = i18next.createInstance().use(i18nextBackend as any);
+    const supportedLang =
+      req.acceptsLanguages().find((l) => isSupportedLang(l)) ?? 'fr';
+    await instance.init<i18nextBackend.FsBackendOptions>({
+      lng: supportedLang,
+      debug: true,
+      backend: {
+        loadPath: `${__dirname}/src/assets/i18n/{{lng}}.json`,
+      },
+    });
+    new LocalizationService(instance);
+  },
+  inject: ['REQUEST'],
+};
+
+export class LocalizationService {
+  constructor(private readonly i18n: i18next.i18n) {}
+
+  translate(key: string) {
+    this.i18n.t(key);
+  }
+}
diff --git a/apps/backend/src/services/logger/logger.service.spec.ts b/apps/backend/src/services/logger/logger.service.spec.ts
new file mode 100644
index 0000000..03ac924
--- /dev/null
+++ b/apps/backend/src/services/logger/logger.service.spec.ts
@@ -0,0 +1,18 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { LoggerService } from './logger.service';
+
+describe('LoggerService', () => {
+  let service: LoggerService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [LoggerService],
+    }).compile();
+
+    service = module.get<LoggerService>(LoggerService);
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+});
diff --git a/apps/backend/src/services/logger/logger.service.ts b/apps/backend/src/services/logger/logger.service.ts
new file mode 100644
index 0000000..5c31077
--- /dev/null
+++ b/apps/backend/src/services/logger/logger.service.ts
@@ -0,0 +1,4 @@
+import { Injectable } from '@nestjs/common';
+
+@Injectable()
+export class LoggerService {}
diff --git a/apps/backend/src/services/mailer/mailer.service.spec.ts b/apps/backend/src/services/mailer/mailer.service.spec.ts
new file mode 100644
index 0000000..1ab5e82
--- /dev/null
+++ b/apps/backend/src/services/mailer/mailer.service.spec.ts
@@ -0,0 +1,18 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { MailerService } from './mailer.service';
+
+describe('MailerService', () => {
+  let service: MailerService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [MailerService],
+    }).compile();
+
+    service = module.get<MailerService>(MailerService);
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+});
diff --git a/apps/backend/src/services/mailer/mailer.service.ts b/apps/backend/src/services/mailer/mailer.service.ts
new file mode 100644
index 0000000..3ad6d83
--- /dev/null
+++ b/apps/backend/src/services/mailer/mailer.service.ts
@@ -0,0 +1,43 @@
+import { Injectable, Logger } from '@nestjs/common';
+import * as nodemailer from 'nodemailer';
+import { SentMessageInfo, Options } from 'nodemailer/lib/smtp-transport';
+import { EnvService } from '../env/env.service';
+
+@Injectable()
+export class MailerService {
+  private readonly logger = new Logger('LoggerService');
+
+  private readonly transport: nodemailer.Transporter<SentMessageInfo, Options>;
+  constructor(envService: EnvService) {
+    const config = envService.config.mail;
+    this.transport = nodemailer.createTransport({
+      host: config.host,
+      port: config.port,
+      secure: true,
+      auth: {
+        user: config.user,
+        pass: config.password,
+      },
+    });
+  }
+
+  async sendEmail(opts: {
+    toAdresses: string[];
+    subject: string;
+    html: string;
+    text?: string;
+  }) {
+    const res = await this.transport.sendMail({
+      from: '"Cowsi" <info@cowsi.ch>',
+      to: opts.toAdresses.join(','),
+      subject: opts.subject,
+      text: opts.text,
+      html: opts.html,
+    });
+    if (res.rejected.length > 0) {
+      this.logger.error('An issue occurred while sending email', res.rejected);
+    } else {
+      this.logger.log('Email sent successfuly');
+    }
+  }
+}
diff --git a/documentation/bruno-rest-api/LocalAPI/Create user.bru b/documentation/bruno-rest-api/LocalAPI/Create user.bru
new file mode 100644
index 0000000..2af33f3
--- /dev/null
+++ b/documentation/bruno-rest-api/LocalAPI/Create user.bru	
@@ -0,0 +1,23 @@
+meta {
+  name: Create user
+  type: http
+  seq: 2
+}
+
+post {
+  url: {{BASE_URL}}/users
+  body: json
+  auth: inherit
+}
+
+body:json {
+  {
+    "firstName": "Paul",
+    "lastName": "Test",
+    "email": "paul@coral.ch"
+  }
+}
+
+settings {
+  encodeUrl: true
+}
diff --git a/documentation/bruno-rest-api/LocalAPI/asdf.bru b/documentation/bruno-rest-api/LocalAPI/asdf.bru
deleted file mode 100644
index 24d76b6..0000000
--- a/documentation/bruno-rest-api/LocalAPI/asdf.bru
+++ /dev/null
@@ -1,15 +0,0 @@
-meta {
-  name: asdf
-  type: http
-  seq: 3
-}
-
-get {
-  url: localhost:5047
-  body: none
-  auth: inherit
-}
-
-settings {
-  encodeUrl: true
-}
diff --git a/documentation/bruno-rest-api/LocalAPI/hello.bru b/documentation/bruno-rest-api/LocalAPI/hello.bru
deleted file mode 100644
index a2c6941..0000000
--- a/documentation/bruno-rest-api/LocalAPI/hello.bru
+++ /dev/null
@@ -1,15 +0,0 @@
-meta {
-  name: hello
-  type: http
-  seq: 2
-}
-
-get {
-  url: {{BASE_URL}}/hello
-  body: none
-  auth: inherit
-}
-
-settings {
-  encodeUrl: true
-}
diff --git a/documentation/bruno-rest-api/LocalAPI/users/folder.bru b/documentation/bruno-rest-api/LocalAPI/users/folder.bru
new file mode 100644
index 0000000..83a5cc9
--- /dev/null
+++ b/documentation/bruno-rest-api/LocalAPI/users/folder.bru
@@ -0,0 +1,8 @@
+meta {
+  name: users
+  seq: 3
+}
+
+auth {
+  mode: inherit
+}
diff --git a/packages/common/src/models/index.ts b/packages/common/src/models/index.ts
index ddf77b4..a54a3b3 100644
--- a/packages/common/src/models/index.ts
+++ b/packages/common/src/models/index.ts
@@ -1 +1,2 @@
 export * from "./users";
+export * from "./lang";
diff --git a/packages/common/src/models/lang.ts b/packages/common/src/models/lang.ts
new file mode 100644
index 0000000..1e0d7c3
--- /dev/null
+++ b/packages/common/src/models/lang.ts
@@ -0,0 +1,6 @@
+export const SUPPORTED_LANGS = ["fr", "en"];
+export type SupportedLangs = (typeof SUPPORTED_LANGS)[number];
+
+export function isSupportedLang(obj: unknown): obj is SupportedLangs {
+  return (SUPPORTED_LANGS as unknown[]).includes(obj);
+}
diff --git a/packages/common/src/models/users/user.ts b/packages/common/src/models/users/user.ts
index b4e7eb6..f8fc7d1 100644
--- a/packages/common/src/models/users/user.ts
+++ b/packages/common/src/models/users/user.ts
@@ -5,12 +5,22 @@ export enum UserTypeEnum {
   Professional = "professional",
 }
 
-export const userParser = z.object({
+const userParser = z.object({
   id: z.string({ message: "inavlid user id" }),
   firstName: z.string({ message: "invalid user first name" }),
   lastName: z.string({ message: "invalid last name" }),
   email: z.string().email({ message: "invalid email" }),
-  type: z.nativeEnum(UserTypeEnum, { message: "invalid user type" }),
+  //type: z.nativeEnum(UserTypeEnum, { message: "invalid user type" }),
+  createdAt: z.date(),
+  updatedAt: z.date(),
+  deletedAt: z.date().optional(),
+});
+
+export const createUserParser = userParser.pick({
+  firstName: true,
+  lastName: true,
+  email: true,
 });
 
 export type User = z.infer<typeof userParser>;
+export type CreateUser = z.infer<typeof createUserParser>;
diff --git a/packages/common/src/utils/index.ts b/packages/common/src/utils/index.ts
index 6b57160..08491d6 100644
--- a/packages/common/src/utils/index.ts
+++ b/packages/common/src/utils/index.ts
@@ -1 +1,2 @@
 export * from "./common";
+export * from "./result";
diff --git a/packages/common/src/utils/result.ts b/packages/common/src/utils/result.ts
new file mode 100644
index 0000000..eb021d4
--- /dev/null
+++ b/packages/common/src/utils/result.ts
@@ -0,0 +1,32 @@
+export type Result<S, E> = ResSuccess<S> | ResError<E>;
+
+export const Result = {
+  success<S>(data: S): Result<S, never> {
+    return new ResSuccess(data);
+  },
+  error<E>(error: E): Result<never, E> {
+    return new ResError(error);
+  },
+} as const;
+
+interface BaseResult<S, E> {
+  map<T>(f: (s: S) => T): Result<T, E>;
+}
+class ResSuccess<S> implements BaseResult<S, never> {
+  readonly ok: true = true;
+
+  constructor(readonly data: S) {}
+
+  map<T>(f: (t: S) => T): Result<T, never> {
+    return new ResSuccess(f(this.data));
+  }
+}
+class ResError<E> implements BaseResult<never, E> {
+  readonly ok: false = false;
+
+  constructor(readonly err: E) {}
+
+  map<T>(): Result<T, E> {
+    return this as Result<T, E>;
+  }
+}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 096ac2c..094e84c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -25,9 +25,18 @@ importers:
       dotenv:
         specifier: ^17.2.1
         version: 17.2.1
+      i18next:
+        specifier: ^25.3.2
+        version: 25.3.2(typescript@5.7.3)
+      i18next-fs-backend:
+        specifier: ^2.6.0
+        version: 2.6.0
       kysely:
         specifier: ^0.28.3
         version: 0.28.3
+      nodemailer:
+        specifier: ^7.0.5
+        version: 7.0.5
       pg:
         specifier: ^8.16.3
         version: 8.16.3
@@ -71,6 +80,9 @@ importers:
       '@types/node':
         specifier: ^22.10.7
         version: 22.16.3
+      '@types/nodemailer':
+        specifier: ^6.4.17
+        version: 6.4.17
       '@types/pg':
         specifier: ^8.15.4
         version: 8.15.4
@@ -324,6 +336,10 @@ packages:
     peerDependencies:
       '@babel/core': ^7.0.0-0
 
+  '@babel/runtime@7.28.2':
+    resolution: {integrity: sha512-KHp2IflsnGywDjBWDkR9iEqiWSpc8GIi0lgTT3mOElT0PP1tG26P4tmFI2YvAdzgq9RGyoHZQEIEdZy6Ec5xCA==}
+    engines: {node: '>=6.9.0'}
+
   '@babel/template@7.27.2':
     resolution: {integrity: sha512-LPDZ85aEJyYSd18/DkjNh4/y1ntkE5KwUHWTiqgRxruuZL2F1yuHligVHLvcHY2vMHXttKFpJn6LwfI7cw7ODw==}
     engines: {node: '>=6.9.0'}
@@ -1034,6 +1050,9 @@ packages:
   '@types/node@22.16.3':
     resolution: {integrity: sha512-sr4Xz74KOUeYadexo1r8imhRtlVXcs+j3XK3TcoiYk7B1t3YRVJgtaD3cwX73NYb71pmVuMLNRhJ9XKdoDB74g==}
 
+  '@types/nodemailer@6.4.17':
+    resolution: {integrity: sha512-I9CCaIp6DTldEg7vyUTZi8+9Vo0hi1/T8gv3C89yk1rSAAzoKQ8H8ki/jBYJSFoH/BisgLP8tkZMlQ91CIquww==}
+
   '@types/pg@8.15.4':
     resolution: {integrity: sha512-I6UNVBAoYbvuWkkU3oosC8yxqH21f4/Jc4DK71JLG3dT2mdlGe1z+ep/LQGXaKaOgcvUrsQoPRqfgtMcvZiJhg==}
 
@@ -2146,6 +2165,17 @@ packages:
     resolution: {integrity: sha512-B4FFZ6q/T2jhhksgkbEW3HBvWIfDW85snkQgawt07S7J5QXTk6BkNV+0yAeZrM5QpMAdYlocGoljn0sJ/WQkFw==}
     engines: {node: '>=10.17.0'}
 
+  i18next-fs-backend@2.6.0:
+    resolution: {integrity: sha512-3ZlhNoF9yxnM8pa8bWp5120/Ob6t4lVl1l/tbLmkml/ei3ud8IWySCHt2lrY5xWRlSU5D9IV2sm5bEbGuTqwTw==}
+
+  i18next@25.3.2:
+    resolution: {integrity: sha512-JSnbZDxRVbphc5jiptxr3o2zocy5dEqpVm9qCGdJwRNO+9saUJS0/u4LnM/13C23fUEWxAylPqKU/NpMV/IjqA==}
+    peerDependencies:
+      typescript: ^5
+    peerDependenciesMeta:
+      typescript:
+        optional: true
+
   iconv-lite@0.4.24:
     resolution: {integrity: sha512-v3MXnZAcvnywkTUEZomIActle7RXXeedOR31wwl7VlyoXO4Qi9arvSenNQWne1TcRwhCL1HwLI21bEqdpj8/rA==}
     engines: {node: '>=0.10.0'}
@@ -2710,6 +2740,10 @@ packages:
   node-releases@2.0.19:
     resolution: {integrity: sha512-xxOWJsBKtzAq7DY0J+DTzuz58K8e7sJbdgwkbMWQe8UYB6ekmsQ45q0M/tJDsGaZmbC+l7n57UV8Hl5tHxO9uw==}
 
+  nodemailer@7.0.5:
+    resolution: {integrity: sha512-nsrh2lO3j4GkLLXoeEksAMgAOqxOv6QumNRVQTJwKH4nuiww6iC2y7GyANs9kRAxCexg3+lTWM3PZ91iLlVjfg==}
+    engines: {node: '>=6.0.0'}
+
   normalize-path@3.0.0:
     resolution: {integrity: sha512-6eZs5Ls3WtCisHWp9S2GUy8dqkpGi4BVSz3GaqiE6ezub0512ESztXUwUB6C6IKbQkY2Pnb/mD4WYojCRwcwLA==}
     engines: {node: '>=0.10.0'}
@@ -3927,6 +3961,8 @@ snapshots:
       '@babel/core': 7.28.0
       '@babel/helper-plugin-utils': 7.27.1
 
+  '@babel/runtime@7.28.2': {}
+
   '@babel/template@7.27.2':
     dependencies:
       '@babel/code-frame': 7.27.1
@@ -4743,6 +4779,10 @@ snapshots:
     dependencies:
       undici-types: 6.21.0
 
+  '@types/nodemailer@6.4.17':
+    dependencies:
+      '@types/node': 22.16.3
+
   '@types/pg@8.15.4':
     dependencies:
       '@types/node': 22.16.3
@@ -6045,6 +6085,14 @@ snapshots:
 
   human-signals@2.1.0: {}
 
+  i18next-fs-backend@2.6.0: {}
+
+  i18next@25.3.2(typescript@5.7.3):
+    dependencies:
+      '@babel/runtime': 7.28.2
+    optionalDependencies:
+      typescript: 5.7.3
+
   iconv-lite@0.4.24:
     dependencies:
       safer-buffer: 2.1.2
@@ -6703,6 +6751,8 @@ snapshots:
 
   node-releases@2.0.19: {}
 
+  nodemailer@7.0.5: {}
+
   normalize-path@3.0.0: {}
 
   normalize-url@8.0.2: {}