diff --git a/README.md b/README.md
index 9b39a70..dbf1b75 100644
--- a/README.md
+++ b/README.md
@@ -42,3 +42,70 @@ SELECT * FROM session;
 Sur la console Keycloak aller dans realm setting
 -> Changer le display name (par exemple: Bienvenue sur Frisbyee !)
 -> Theme puis changer le login theme sur frisbyee
+
+## Domain model class diagram
+
+```mermaid
+classDiagram
+  %% Classes and attributes (inferred from metier package)
+  class User {
+    +Long id
+    +String keycloakId
+    +String email
+    +String nom
+    +String prenom
+    +Role role
+  }
+
+  class Athlete {
+    +String categorie
+    +String niveau
+    +List<String> groupe
+    +List<Session> sessions
+  }
+
+  %% Represente en enum
+  class Role {
+    +String role
+  }
+
+  class Coach {
+    +List<Session> sessions
+  }
+
+  class Admin {
+  }
+
+  class Activite {
+    +Long id
+    +String nom
+    +String theme
+    +String description
+    +Integer dureeMinutes
+    +List<Activite> activites
+    +Session session
+  }
+
+  class Session {
+    +Long id
+    +String name
+    +LocalDateTime creneau
+    +Integer duree
+    +String group
+    +bool isRecurrent
+    +Coach coach
+    +List<Athlete> athletes
+  }
+
+  %% Inheritance (if User is a base class for domain actors)
+  User <|-- Athlete
+  User <|-- Coach
+  User <|-- Admin
+
+  %% Associations with cardinality
+  Coach "1" -- "0..*" Session : manages
+  Role "1" -- "0..*" User : is
+  Session "0..*" -- "0..*" Activite : contains
+  Session "0..*" -- "0..*" Athlete : participants
+  Activite "0..*" -- "0..*" Session : usedIn
+```