diff --git a/back_end/src/main/java/hackathon/FrisbYEE/rest/SessionResource.java b/back_end/src/main/java/hackathon/FrisbYEE/rest/SessionResource.java
index 172d108..da1f786 100644
--- a/back_end/src/main/java/hackathon/FrisbYEE/rest/SessionResource.java
+++ b/back_end/src/main/java/hackathon/FrisbYEE/rest/SessionResource.java
@@ -130,6 +130,18 @@ public class SessionResource {
             return ResponseEntity.ok(activiteDTOs);
         } catch (Exception ex) {
             return ResponseEntity.status(HttpStatus.NOT_FOUND).body(ex.getMessage());
+    //Commented because not finished
+
+    @GetMapping("/{id_session}/activities/add/{id_act}")
+    @PreAuthorize("hasRole('coach') or hasRole('admin')")
+    public ResponseEntity<?> addActivity(@PathVariable Integer id_sess, @PathVariable Integer id_act) {
+        Session s = sessionDAO.findById(id_sess).get();
+        if(s.equals(null)){
+            return ResponseEntity.status(HttpStatus.NOT_FOUND).body("Session not found");
+        }
+        Activite a = activiteDAO.findById(id_act).get();
+        if(a.equals(null)){
+            return ResponseEntity.status(HttpStatus.NOT_FOUND).body("Activite not found");
         }
     }
 
@@ -137,7 +149,7 @@ public class SessionResource {
 
     /*
      * @GetMapping("/activities/add")
-     * 
+     *
      * @PreAuthorize("hasRole('coach') or hasRole('admin')")
      * public ResponseEntity<?> addActivity(@RequestBody ActiviteDTO dto) {
      * try {
@@ -149,6 +161,12 @@ public class SessionResource {
      * }
      * }
      */
+        List<Activite> l = s.getActivites();
+        l.add(a);
+        s.setActivites(l);
+        sessionDAO.save(s);
+        return ResponseEntity.status(200).body(maptoDTO(s));
+    }
 
     private SessionDTO maptoDTO(Session s) {
         SessionDTO dto = new SessionDTO();
@@ -183,13 +201,13 @@ public class SessionResource {
 
     private Session maptoEntity(SessionDTO dto) {
         Session session = new Session();
-        System.out.println("ID " + session.getId());
+        System.out.println("ID "+ session.getId());
         session.setName(dto.getName());
         session.setIsRecurrent(dto.getIsRecurrent());
         session.setCreneau(dto.getCreneau());
         session.setDuree(dto.getDuree());
         session.setGroupe(dto.getGroupe());
-
+        
         return session;
     }
 }
diff --git a/front_end/src/api.ts b/front_end/src/api.ts
index bd74948..cf5a953 100644
--- a/front_end/src/api.ts
+++ b/front_end/src/api.ts
@@ -50,6 +50,7 @@ export const athleteService = {
     getActivitiesForSession: (sessionId: number | string) => api.get(`/athletes/session/${sessionId}/activities`),
     getSessionsAfterDate: (athleteId: number | string, date: string) => api.get(`/athletes/${athleteId}/session/after/${encodeURIComponent(date)}`),
     getSessionsBetweenDates: (athleteId: number | string, startDate: string, endDate: string) => api.get(`/athletes/${athleteId}/session/between/${encodeURIComponent(startDate)}/${encodeURIComponent(endDate)}`),
+    addActivity: (id_sess: number, id_act: number) => api.get(`/${id_sess}/activities/add/${id_act}`)
 };
 
 export const activiteService = {
@@ -70,10 +71,10 @@ export const sessionService = {
     delete: (id: number | string) => api.delete(`/session/delete/${id}`),
     update: (id: number | string, data: any) => api.put(`/session/update/${id}`, data),
 
-    getActivities: (sessionId: number | string) => api.get(`/sessions/${sessionId}/activities`),
-    addActivity: (sessionId: number | string, activity: any) => api.post(`/sessions/${sessionId}/activities`, activity),
-    subscribe: (sessionId: number | string, userId: number | string) => api.post(`/sessions/${sessionId}/subscribe`, { userId }),
-    unsubscribe: (sessionId: number | string, userId: number | string) => api.post(`/sessions/${sessionId}/unsubscribe`, { userId }),
+    getActivities: (sessionId: number | string) => api.get(`/session/${sessionId}/activities`),
+    addActivity: (sessionId: number | string, activity: any) => api.post(`/session/${sessionId}/activities`, activity),
+    subscribe: (sessionId: number | string, userId: number | string) => api.post(`/session/${sessionId}/subscribe`, { userId }),
+    unsubscribe: (sessionId: number | string, userId: number | string) => api.post(`/session/${sessionId}/unsubscribe`, { userId }),
 };
 
 export const coachService = {
diff --git a/front_end/src/requetes.tsx b/front_end/src/requetes.tsx
index b5ff9c4..836c2f2 100644
--- a/front_end/src/requetes.tsx
+++ b/front_end/src/requetes.tsx
@@ -66,15 +66,20 @@ export async function loginOrRegister(keycloak:Keycloak): Promise<User|null>{
     }   
 }
 
-export async function updateActivitiesOfSessionAPI(session:Session,activities:Activite[]){
+export async function updateActivitiesOfSessionAPI(session:Session){
     try {
         const session_id = session.id
-        for (const activity of activities) {
-            const response = await activiteService.update(activity.id!, activity.toDTO());
-        }
+        console.log("TEST:");
+        console.log(session.activites);
+        session.activites.forEach(activite => {
+            console.log("FOR");
+            if(activite.id!=null){
+                activiteService.update(activite.id, activite.toDTO());
+            }
+        });
         // To refresh the activities in the session object
-        const response = await sessionService.getActivities(session_id!);
-        session.activites = response.data;
+        //const response = await sessionService.getActivities(session_id!);
+        //session.activites = response.data;
     } catch (error) {
         console.error("Error fetching activities for session:", error);
     }
@@ -113,16 +118,20 @@ export async function createSessionAPI(session: Session): Promise<Session> {
     async function postActivite(activite:Activite,sessionRes:Session){
         activite.session = sessionRes;
         const activite2 = await createActivityAPI(activite);
+        activite2.session = sessionRes;
         sessionRes.activites.push(activite2);
     }
 
     try {
         const response = await api.post<SessionDTO>("/session/create", session.toDTO());
         const sessionRes:Session = new Session(response.data);
-        await session.activites.forEach(activite => {
-            postActivite(activite,sessionRes);
-        });
-        updateActivitiesOfSessionAPI(session,session.activites);
+        await Promise.all(
+            session.activites.map(activite =>
+                postActivite(activite, sessionRes)
+            )
+        );
+        console.log(sessionRes.activites);
+        updateActivitiesOfSessionAPI(sessionRes);
 
         return sessionRes;
     } catch (error) {