diff --git a/notus/Biblioteque_de_Class/IManager.cs b/notus/Biblioteque_de_Class/IManager.cs
new file mode 100644
index 0000000..74f98cc
--- /dev/null
+++ b/notus/Biblioteque_de_Class/IManager.cs
@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Biblioteque_de_Class
+{
+    public interface IManager
+    {
+        public void SaveDatabaseData(Database database);
+
+        public Database LoadDatabaseData();
+
+        public void SaveUserData(User user);
+
+        public User LoadUserData();
+    }
+}
diff --git a/notus/Biblioteque_de_Class/Manager.cs b/notus/Biblioteque_de_Class/Manager.cs
new file mode 100644
index 0000000..90faa60
--- /dev/null
+++ b/notus/Biblioteque_de_Class/Manager.cs
@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Biblioteque_de_Class
+{
+    public class Manager
+    {
+        private IManager persistence;
+
+        public Manager(IManager pers) 
+        {
+            persistence = pers; 
+        }
+
+        public  void SaveDatabaseData(Database database)
+        {
+            persistence.SaveDatabaseData(database);
+        }
+
+        public  Database LoadDatabaseData()
+        {
+            return persistence.LoadDatabaseData();
+        }
+
+        public  void SaveUserData(User user)
+        {
+            persistence.SaveUserData(user);
+        }
+
+        public  User LoadUserData()
+        {
+            return persistence.LoadUserData();
+        }
+    }
+}
diff --git a/notus/Notus_Persistence/Stub.cs b/notus/Notus_Persistence/Stub.cs
index 7d349b3..d7c6135 100644
--- a/notus/Notus_Persistence/Stub.cs
+++ b/notus/Notus_Persistence/Stub.cs
@@ -8,7 +8,7 @@ using System.Threading.Tasks;
 
 namespace Notus_Persistance
 {
-    public class Stub
+    internal class Stub : IManager
     {
         public void SaveDatabaseData(Database database)
         {
diff --git a/notus/Notus_Persistence/ToJSON.cs b/notus/Notus_Persistence/ToJSON.cs
index 3c2e342..9ff522a 100644
--- a/notus/Notus_Persistence/ToJSON.cs
+++ b/notus/Notus_Persistence/ToJSON.cs
@@ -12,7 +12,7 @@ using System.Text.Json;
 
 namespace Notus_Persistance
 {
-    public class ToJSON
+    public class ToJSON : IManager
     {
         private const string DatabaseDataFilePath = "data.json";
         private const string UserDataFilePath = "userdata.json";
diff --git a/notus/Notus_Persistence/ToXML.cs b/notus/Notus_Persistence/ToXML.cs
index 30a7bed..47332f0 100644
--- a/notus/Notus_Persistence/ToXML.cs
+++ b/notus/Notus_Persistence/ToXML.cs
@@ -10,7 +10,7 @@ using System.Threading.Tasks;
 
 namespace Notus_Persistance
 {
-    public class ToXML
+    public class ToXML : IManager
     {
         private const string DataFilePath = "data.xml";
         private const string XmlDataFilePath = "userdata.xml";