diff --git a/auth/instance.go b/auth/instance.go
index aa1caee..ea3bf32 100644
--- a/auth/instance.go
+++ b/auth/instance.go
@@ -14,7 +14,7 @@ type Builder[
 	M SigningMethod,
 	T Alg[S, V, M],
 ] struct {
-	manager *Manager[S, V, M, T]
+	manager *TokenManager[S, V, M, T]
 }
 
 // InstanceBuilder returns a Builder instance.
@@ -25,7 +25,7 @@ func InstanceBuilder[
 	T Alg[S, V, M],
 ](alg T) *Builder[S, V, M, T] {
 	return &Builder[S, V, M, T]{
-		manager: &Manager[S, V, M, T]{
+		manager: &TokenManager[S, V, M, T]{
 			alg:            alg,
 			timeout:        time.Minute * 5,
 			refreshTimeout: time.Hour * 24 * 7,
@@ -47,22 +47,22 @@ func (b *Builder[S, V, M, T]) SetRefreshTimeout(timeout time.Duration) *Builder[
 
 func (b *Builder[S, V, M, T]) Build() *Instance {
 	return &Instance{
-		TokenManager: b.manager,
+		ITokenManager: b.manager,
 	}
 }
 
 type Instance struct {
-	TokenManager
+	ITokenManager
 }
 
 // Sign returns a signed jwt string.
 func (e *Instance) Sign(uid string) (token string, err error) {
-	return e.TokenManager.SignWithClaims(uid, nil)
+	return e.SignWithClaims(uid, nil)
 }
 
 // CheckToken accept a jwt token and returns the uid in token.
 func (e *Instance) CheckToken(token string) (userID string, err error) {
-	t, err := e.TokenManager.ParseToken(token)
+	t, err := e.ParseToken(token)
 	if err != nil {
 		return "", fmt.Errorf("parse token: %w", err)
 	}
diff --git a/auth/interface.go b/auth/interface.go
index 809c5ad..1b8beac 100644
--- a/auth/interface.go
+++ b/auth/interface.go
@@ -26,7 +26,7 @@ type SigningMethod interface {
 	jwt.SigningMethod
 }
 
-type TokenManager interface {
+type ITokenManager interface {
 	// SignWithClaims signs the token with the given claims.
 	SignWithClaims(uid string, claims map[string]any) (token string, err error)
 	// ParseToken parses the token string and returns a jwt.Token and an error.
diff --git a/auth/manager.go b/auth/manager.go
index f636273..10f08f3 100644
--- a/auth/manager.go
+++ b/auth/manager.go
@@ -8,7 +8,7 @@ import (
 	"github.com/golang-jwt/jwt/v5"
 )
 
-type Manager[
+type TokenManager[
 	S SigningKey,
 	V VerifyKey,
 	M SigningMethod,
@@ -20,7 +20,7 @@ type Manager[
 }
 
 // SignWithClaims signs the token with the given claims.
-func (i *Manager[S, V, M, T]) SignWithClaims(uid string, claims map[string]any) (token string, err error) {
+func (i *TokenManager[S, V, M, T]) SignWithClaims(uid string, claims map[string]any) (token string, err error) {
 	now := time.Now()
 	_claims := jwt.MapClaims{
 		"uid": uid,
@@ -40,7 +40,7 @@ func (i *Manager[S, V, M, T]) SignWithClaims(uid string, claims map[string]any)
 }
 
 // ParseToken parse a token string.
-func (i *Manager[S, V, M, T]) ParseToken(token string) (*jwt.Token, error) {
+func (i *TokenManager[S, V, M, T]) ParseToken(token string) (*jwt.Token, error) {
 	return jwt.Parse(token, func(token *jwt.Token) (interface{}, error) {
 		if _, methodOK := token.Method.(M); !methodOK {
 			signingErr := fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
@@ -62,7 +62,7 @@ func (i *Manager[S, V, M, T]) ParseToken(token string) (*jwt.Token, error) {
 
 // RefreshToken accepts a valid token and
 // returns a new token with new expire time.
-func (i *Manager[S, V, M, T]) RefreshToken(token string) (newToken string, err error) {
+func (i *TokenManager[S, V, M, T]) RefreshToken(token string) (newToken string, err error) {
 	t, err := i.ParseToken(token)
 	if err != nil {
 		return "", fmt.Errorf("parse token: %w", err)