diff --git a/Knots/Models/Discussion.cs b/Knots/Models/Discussion.cs
index 967c177..eb1502b 100644
--- a/Knots/Models/Discussion.cs
+++ b/Knots/Models/Discussion.cs
@@ -1,6 +1,8 @@
+using System.ComponentModel.DataAnnotations;
+
 namespace Knots.Models;
 
 public class Discussion
 {
-    
+    [Key] public int Id { get; set; }
 }
\ No newline at end of file
diff --git a/Knots/Models/Group.cs b/Knots/Models/Group.cs
index f9744a9..47e22b2 100644
--- a/Knots/Models/Group.cs
+++ b/Knots/Models/Group.cs
@@ -1,13 +1,12 @@
 using System.ComponentModel.DataAnnotations;
+using System.Net.Mime;
 
 namespace Knots.Models;
 
 public class Group
 {
     [Key] public int Id { get; set; }
-    [Required, MaxLength(100)] public string? FirstName { get; set; }
-    [Required, MaxLength(100)] public string? LastName { get; set; }
-    [MaxLength(2000)] public string? Biography { get; set; }
-    [Required] public DateOnly BirthDate { get; set; }
-    [Required, MaxLength(60)] public string? Nationality { get; set; }
+    [Required, MaxLength(50)] public string? Nom { get; set; }
+    [Required] public int NombreMembres { get; set; }
+    public string? ProfilePicture { get; set; }
 }
\ No newline at end of file
diff --git a/Knots/Models/Key.cs b/Knots/Models/Key.cs
index f586e7c..f222555 100644
--- a/Knots/Models/Key.cs
+++ b/Knots/Models/Key.cs
@@ -1,6 +1,9 @@
+using System.ComponentModel.DataAnnotations;
+
 namespace Knots.Models;
 
 public class Key
 {
-    
+    [Key] public int Id { get; set; }
+    [Required, MaxLength(50)] public string? EnKey { get; set; }
 }
\ No newline at end of file
diff --git a/Knots/Models/Message.cs b/Knots/Models/Message.cs
index 195817c..1545670 100644
--- a/Knots/Models/Message.cs
+++ b/Knots/Models/Message.cs
@@ -1,6 +1,11 @@
+using System.ComponentModel.DataAnnotations;
+
 namespace Knots.Models;
 
 public class Message
 {
-    
+    [Key] public int Id { get; set; }
+    [Required, MaxLength(1000)] public string? Contenu { get; set; }
+    [Required] public DateTime Date { get; set; }
+    [Required] public Boolean Type { get; set; }
 }
\ No newline at end of file