diff --git a/internal/account/handler.go b/internal/account/handler.go
index 96c3d6e..84df5b3 100644
--- a/internal/account/handler.go
+++ b/internal/account/handler.go
@@ -4,50 +4,13 @@ import (
 	"errors"
 
 	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
 )
 
 type AccountHandler struct {
 	accountService *AccountService
 }
 
-type CreateAccountRequest struct {
-	Username string `json:"username"`
-	Password string `json:"password"`
-}
-
-type RenameRequest struct {
-	NewUsername string `json:"new_username"`
-}
-
-type FindByIDRequest struct {
-	ID uint `json:"id"`
-}
-
-type FindByIDResponse struct {
-	ID       uint   `json:"id"`
-	Username string `json:"username"`
-}
-
-type FindByUsernameRequest struct {
-	Username string `json:"username"`
-}
-
-type FindByUsernameResponse struct {
-	ID       uint   `json:"id"`
-	Username string `json:"username"`
-}
-
-type ChangePasswordRequest struct {
-	Username    string `json:"username"`
-	OldPassword string `json:"old_password"`
-	NewPassword string `json:"new_password"`
-}
-
-type LoginRequest struct {
-	Username string `json:"username"`
-	Password string `json:"password"`
-}
-
 func NewAccountHandler(accountService *AccountService) *AccountHandler {
 	return &AccountHandler{accountService: accountService}
 }
@@ -78,11 +41,24 @@ func (h *AccountHandler) Rename(c *gin.Context) {
 		c.JSON(400, gin.H{"error": err.Error()})
 		return
 	}
-	if err := h.accountService.Rename(c.Request.Context(), accountID, req.NewUsername); err != nil {
+	token, err := h.accountService.Rename(c.Request.Context(), accountID, req.NewUsername)
+	if err != nil {
+		if errors.Is(err, ErrNewUsernameRequired) {
+			c.JSON(400, gin.H{"error": err.Error()})
+			return
+		}
+		if errors.Is(err, ErrUsernameTaken) {
+			c.JSON(409, gin.H{"error": err.Error()})
+			return
+		}
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			c.JSON(404, gin.H{"error": "account not found"})
+			return
+		}
 		c.JSON(500, gin.H{"error": err.Error()})
 		return
 	}
-	c.JSON(200, gin.H{"message": "account renamed"})
+	c.JSON(200, gin.H{"token": token})
 }
 
 func (h *AccountHandler) ChangePassword(c *gin.Context) {
diff --git a/internal/account/repo.go b/internal/account/repo.go
index fcc6796..f4a0e61 100644
--- a/internal/account/repo.go
+++ b/internal/account/repo.go
@@ -22,12 +22,32 @@ func (ar *AccountRepository) CreateAccount(ctx context.Context, account *Account
 }
 
 func (ar *AccountRepository) Rename(ctx context.Context, id uint, newUsername string) error {
-	if err := ar.db.WithContext(ctx).Model(&Account{}).Where("id = ?", id).Update("username", newUsername).Error; err != nil {
-		return err
+	result := ar.db.WithContext(ctx).Model(&Account{}).Where("id = ?", id).Update("username", newUsername)
+	if result.Error != nil {
+		return result.Error
+	}
+	if result.RowsAffected == 0 {
+		return gorm.ErrRecordNotFound
 	}
 	return nil
 }
 
+func (ar *AccountRepository) RenameWithToken(ctx context.Context, id uint, newUsername string, token string) error {
+	return ar.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+		result := tx.Model(&Account{}).Where("id = ?", id).Update("username", newUsername)
+		if result.Error != nil {
+			return result.Error
+		}
+		if result.RowsAffected == 0 {
+			return gorm.ErrRecordNotFound
+		}
+		if err := tx.Model(&Account{}).Where("id = ?", id).Update("token", token).Error; err != nil {
+			return err
+		}
+		return nil
+	})
+}
+
 func (ar *AccountRepository) ChangePassword(ctx context.Context, id uint, newPassword string) error {
 	if err := ar.db.WithContext(ctx).Model(&Account{}).Where("id = ?", id).Update("password", newPassword).Error; err != nil {
 		return err
diff --git a/internal/account/service.go b/internal/account/service.go
index 9850b32..f367c7a 100644
--- a/internal/account/service.go
+++ b/internal/account/service.go
@@ -5,13 +5,20 @@ import (
 	"errors"
 	"feedsystem_video_go/internal/auth"
 
+	"github.com/go-sql-driver/mysql"
 	"golang.org/x/crypto/bcrypt"
+	"gorm.io/gorm"
 )
 
 type AccountService struct {
 	accountRepository *AccountRepository
 }
 
+var (
+	ErrUsernameTaken       = errors.New("username already exists")
+	ErrNewUsernameRequired = errors.New("new_username is required")
+)
+
 func NewAccountService(accountRepository *AccountRepository) *AccountService {
 	return &AccountService{accountRepository: accountRepository}
 }
@@ -28,11 +35,28 @@ func (as *AccountService) CreateAccount(ctx context.Context, account *Account) e
 	return nil
 }
 
-func (as *AccountService) Rename(ctx context.Context, accountID uint, newUsername string) error {
-	if err := as.accountRepository.Rename(ctx, accountID, newUsername); err != nil {
-		return err
+func (as *AccountService) Rename(ctx context.Context, accountID uint, newUsername string) (string, error) {
+	if newUsername == "" {
+		return "", ErrNewUsernameRequired
 	}
-	return nil
+
+	token, err := auth.GenerateToken(accountID, newUsername)
+	if err != nil {
+		return "", err
+	}
+
+	if err := as.accountRepository.RenameWithToken(ctx, accountID, newUsername, token); err != nil {
+		var mysqlErr *mysql.MySQLError
+		if errors.As(err, &mysqlErr) && mysqlErr.Number == 1062 {
+			return "", ErrUsernameTaken
+		}
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return "", err
+		}
+		return "", err
+	}
+
+	return token, nil
 }
 
 func (as *AccountService) ChangePassword(ctx context.Context, username, oldPassword, newPassword string) error {