diff --git a/docs/API.md b/docs/API.md
index 664753e..ad20f53 100644
--- a/docs/API.md
+++ b/docs/API.md
@@ -46,7 +46,7 @@ Body:
 
 ```json
 {
-  "username": "maria",
+  "email": "maria",
   "password": "123456",
   "encrypted_master_key": "texto_cifrado_opcional",
   "deviceName": "Flutter Pixel"
@@ -55,7 +55,7 @@ Body:
 
 Campos:
 
-- `username`: `string`, obligatorio.
+- `email`: `string`, obligatorio.
 - `password`: `string`, obligatorio.
 - `encrypted_master_key`: `string | null`, opcional.
 
@@ -77,7 +77,7 @@ Body:
 
 ```json
 {
-  "username": "maria",
+  "email": "maria",
   "password": "123456",
   "deviceName": "Flutter Pixel"
 }
@@ -85,7 +85,7 @@ Body:
 
 Campos:
 
-- `username`: `string`, obligatorio.
+- `email`: `string`, obligatorio.
 - `password`: `string`, obligatorio.
 - `deviceName`: `string`, opcional.
 
diff --git a/src/controllers/authController.js b/src/controllers/authController.js
index dbe9b21..32aac7d 100644
--- a/src/controllers/authController.js
+++ b/src/controllers/authController.js
@@ -11,19 +11,19 @@ if (!JWT_SECRET) {
 const register = async (req, res) => {
   try {
     console.log(req.body); // Log completo del body para depuración
-    const { username, password, encrypted_master_key, deviceName } = req.body;
+    const { email, password, encrypted_master_key, deviceName } = req.body;
     
-    if (!username || !password) {
+    if (!email || !password) {
       return res.status(400).json({ error: 'Usuario y contraseña son obligatorios' });
     }
-    console.log(`Intentando registrar usuario: ${username}`);
+    console.log(`Intentando registrar usuario: ${email}`);
     console.log(`Encrypted Master Key recibida: ${encrypted_master_key}`);
     // Registramos el usuario y emitimos tokens para entrar directamente
-    await authService.register(username, password, encrypted_master_key);
+    await authService.register(email, password, encrypted_master_key);
 
     // Generamos tokens reutilizando el flujo de login (no hay deviceName en register)
     const nombreDispositivo = deviceName || req.headers['user-agent'] || 'Dispositivo Desconocido';
-    const { accessToken, refresh_token } = await authService.login(username, password, nombreDispositivo);
+    const { accessToken, refresh_token } = await authService.login(email, password, nombreDispositivo);
 
     res.status(201).json({
       message: 'Usuario registrado con éxito',
@@ -38,12 +38,12 @@ const register = async (req, res) => {
 // 2. LOGIN
 const login = async (req, res) => {
   try {
-    const { username, password, deviceName } = req.body;
+    const { email, password, deviceName } = req.body;
     
     // Si Flutter no envía un nombre, intentamos leer el User-Agent
     const nombreDispositivo = deviceName || req.headers['user-agent'] || 'Dispositivo Desconocido';
 
-    const { encrypted_master_key, accessToken, refresh_token } = await authService.login(username, password, nombreDispositivo);
+    const { encrypted_master_key, accessToken, refresh_token } = await authService.login(email, password, nombreDispositivo);
 
     res.json({
       message: 'Login exitoso',
diff --git a/src/models/User.js b/src/models/User.js
index 390ca6e..f6df9f6 100644
--- a/src/models/User.js
+++ b/src/models/User.js
@@ -7,7 +7,7 @@ const User = sequelize.define('User', {
     defaultValue: DataTypes.UUIDV4,
     primaryKey: true,
   },
-  username: { 
+  email: { 
     type: DataTypes.STRING, 
     allowNull: false, 
     unique: true 
diff --git a/src/services/authService.js b/src/services/authService.js
index c886d9d..93c5e59 100644
--- a/src/services/authService.js
+++ b/src/services/authService.js
@@ -15,19 +15,19 @@ if (!JWT_SECRET) {
 
 class AuthService {
   
-  async register(username, password, encrypted_master_key = null) {
-    const userExists = await User.findOne({ where: { username } });
+  async register(email, password, encrypted_master_key = null) {
+    const userExists = await User.findOne({ where: { email: email } });
     if (userExists) throw new Error('El usuario ya existe');
 
     const salt = await bcrypt.genSalt(10);
     const hashedPassword = await bcrypt.hash(password, salt);
 
-    return await User.create({ username, password: hashedPassword, encrypted_master_key });
+    return await User.create({ email: email, password: hashedPassword, encrypted_master_key });
   }
 
   // LOGIN: Crea el Access Token corto y registra el dispositivo con un Refresh Token único
-  async login(username, password, deviceName) {
-    const user = await User.findOne({ where: { username } });
+  async login(email, password, deviceName) {
+    const user = await User.findOne({ where: { email: email } });
     if (!user) throw new Error('Credenciales inválidas');
 
     const isValid = await bcrypt.compare(password, user.password);
@@ -35,7 +35,7 @@ class AuthService {
 
     // A. Generar Access Token (Vence en 15 minutos - Sin datos sensibles)
     const accessToken = jwt.sign(
-      { id: user.id, username: user.username },
+      { id: user.id, email: user.email },
       JWT_SECRET,
       { expiresIn: '15m' }
     );
@@ -69,7 +69,7 @@ class AuthService {
 
     // 2. Si existe, emitimos un nuevo Access Token de 15 minutos
     const newAccessToken = jwt.sign(
-      { id: user.id, username: user.username },
+      { id: user.id, email: user.email },
       JWT_SECRET,
       { expiresIn: '15m' }
     );