diff --git a/src/app/components/comment-form/comment-form.component.ts b/src/app/components/comment-form/comment-form.component.ts
index 47061e4..56d2dca 100644
--- a/src/app/components/comment-form/comment-form.component.ts
+++ b/src/app/components/comment-form/comment-form.component.ts
@@ -51,7 +51,7 @@ export class CommentFormComponent {
           this.successMessage("Succès", "Commentaire créé avec succès");
         },
         error: (error) => {
-          this.failureMessage("Erreur d'envois", error.message);
+          this.failureMessage("Erreur d'envois", error.error.message);
         }
       }))
     }
diff --git a/src/app/components/header/header.component.ts b/src/app/components/header/header.component.ts
index 679d081..1ff54ca 100644
--- a/src/app/components/header/header.component.ts
+++ b/src/app/components/header/header.component.ts
@@ -4,6 +4,7 @@ import {MenubarModule} from 'primeng/menubar';
 import {ToastModule} from 'primeng/toast';
 import {Author} from '../../models/author';
 import {AuthService} from '../../auth.service';
+import {Role} from '../../models/role'
 
 @Component({
   selector: 'app-header',
@@ -44,19 +45,19 @@ export class HeaderComponent {
       }
     ];
 
-    if (author.role === 'WRITER') {
+    if (author.role === Role.WRITER) {
       return [
         ...commonItems,
         this.getWriterMenu(),
         this.getUserMenu(author)
       ];
-    } else if (author.role === 'ADMIN') {
+    } else if (author.role === Role.ADMIN) {
       return [
         ...commonItems,
         this.getAdminMenu(),
         this.getUserMenu(author)
       ];
-    } else if (author.role === 'READER') {
+    } else if (author.role === Role.READER) {
       return [
         ...commonItems,
         this.getUserMenu(author)
diff --git a/src/app/components/post-form/post-form.component.ts b/src/app/components/post-form/post-form.component.ts
index c3573bc..e0da7ee 100644
--- a/src/app/components/post-form/post-form.component.ts
+++ b/src/app/components/post-form/post-form.component.ts
@@ -79,7 +79,7 @@ export class PostFormComponent implements OnDestroy {
             });
           },
           error: (err) => {
-            this.failureMessage('Erreur', `Impossible de charger le post : ${err.message}`);
+            this.failureMessage('Erreur', err.error.message);
           }
         })
       );
@@ -113,7 +113,7 @@ export class PostFormComponent implements OnDestroy {
             next: (_) => {
               this.successMessage('Succès', 'Post mis à jour avec succès')
             },
-            error: (err) => this.failureMessage('Erreur', err.message)
+            error: (err) => this.failureMessage('Erreur', err.error.message)
           })
         );
       } else {
@@ -132,7 +132,7 @@ export class PostFormComponent implements OnDestroy {
                 this.successMessage('Succès', 'Post créé avec succès')
               });
             },
-            error: (err) => this.failureMessage('Erreur', err.message)
+            error: (err) => this.failureMessage('Erreur', err.error.message)
           })
         );
       }
diff --git a/src/app/components/register-form/register-form.component.ts b/src/app/components/register-form/register-form.component.ts
index 6a62d22..04f09db 100644
--- a/src/app/components/register-form/register-form.component.ts
+++ b/src/app/components/register-form/register-form.component.ts
@@ -9,6 +9,7 @@ import {Router} from '@angular/router';
 import {MessageService} from 'primeng/api';
 import {Author} from '../../models/author';
 import {AuthService} from '../../auth.service';
+import {Role} from '../../models/role';
 
 @Component({
   selector: 'app-register-form',
@@ -28,11 +29,11 @@ export class RegisterFormComponent implements OnDestroy {
   @Output() createdAuthor: EventEmitter<Author> = new EventEmitter();
   @Input() password: string = "";
   @Input() passwordConfirm: string = "";
-  @Input() role: string = "READER"
+  @Input() role: string = Role.READER
   @Input() adminForm: boolean = false;
   roles = [
-    {name: 'Lecteur', value: 'READER'},
-    {name: 'Écrivain', value: 'WRITER'}
+    {name: 'Lecteur', value: Role.READER},
+    {name: 'Écrivain', value: Role.WRITER}
   ];
   subs: Subscription[] = [];
   form: FormGroup;
@@ -51,7 +52,7 @@ export class RegisterFormComponent implements OnDestroy {
       username: ['', [Validators.required, Validators.maxLength(255)]],
       password: ['', [Validators.required, Validators.maxLength(50)]],
       passwordConfirm: ['', [Validators.required, Validators.maxLength(50)]],
-      role: [{value: 'READER'}, [Validators.required, Validators.maxLength(10)]],
+      role: [{value: Role.READER}, [Validators.required, Validators.maxLength(10)]],
     });
   }
 
@@ -88,13 +89,13 @@ export class RegisterFormComponent implements OnDestroy {
             this.createdAuthor.emit(author);
           },
           error: (err) => {
-            this.failureMessage("Erreur", err.message);
+            this.failureMessage("Erreur", err.error.message);
           }
         });
       } else {
         this.subs.push(this.authorService.createAccount(this.username, this.password).subscribe({
           next: () => this.router.navigate(['/login']).then(() => this.successMessage('Succès', 'Utilisateur créé avec succès')),
-          error: (err) => this.failureMessage('Erreur', err.message)
+          error: (err) => this.failureMessage('Erreur', err.error.message)
 
         }));
       }
diff --git a/src/app/components/update-profile-form/update-profile-form.component.ts b/src/app/components/update-profile-form/update-profile-form.component.ts
index d73cdb1..6900917 100644
--- a/src/app/components/update-profile-form/update-profile-form.component.ts
+++ b/src/app/components/update-profile-form/update-profile-form.component.ts
@@ -96,7 +96,7 @@ export class UpdateProfileFormComponent implements OnDestroy {
             this.router.navigate(['/']);
           },
           error: (err) => {
-            this.failureMessage("Erreur", err.message);
+            this.failureMessage("Erreur", err.error.error.message);
           }
         }));
       } else {
@@ -108,7 +108,7 @@ export class UpdateProfileFormComponent implements OnDestroy {
             this.router.navigate(['/']);
           },
           error: (err) => {
-            this.failureMessage("Erreur", err.message);
+            this.failureMessage("Erreur", err.error.error.message);
           }
         }));
       }
diff --git a/src/app/guards/admin.guard.ts b/src/app/guards/admin.guard.ts
index 7137c05..5e90c8d 100644
--- a/src/app/guards/admin.guard.ts
+++ b/src/app/guards/admin.guard.ts
@@ -1,15 +1,15 @@
 import {CanActivateFn, Router} from '@angular/router';
 import {inject} from '@angular/core';
 import {CookieService} from 'ngx-cookie-service';
-import {Author} from '../models/author';
 import {AuthService} from '../auth.service';
+import {Role} from '../models/role';
 
 export const adminGuard: CanActivateFn = (route, state) => {
   const router = inject(Router);
   const cookieService = inject(CookieService);
   const authService: AuthService = inject(AuthService);
 
-  if ((authService.isAuthenticated() && JSON.parse(cookieService.get("author")).role !== 'ADMIN') || !authService.isAuthenticated()) {
+  if ((authService.isAuthenticated() && JSON.parse(cookieService.get("author")).role !== Role.ADMIN) || !authService.isAuthenticated()) {
     router.navigate(['/']);
   }
 
diff --git a/src/app/guards/writer.guard.ts b/src/app/guards/writer.guard.ts
index 7fa5965..ad596bd 100644
--- a/src/app/guards/writer.guard.ts
+++ b/src/app/guards/writer.guard.ts
@@ -2,13 +2,14 @@ import {CanActivateFn, Router} from '@angular/router';
 import {inject} from '@angular/core';
 import {CookieService} from 'ngx-cookie-service';
 import {AuthService} from '../auth.service';
+import {Role} from '../models/role';
 
 export const writerGuard: CanActivateFn = (route, state) => {
   const router = inject(Router);
   const cookieService = inject(CookieService);
   const authService = inject(AuthService);
 
-  if ((authService.isAuthenticated() && JSON.parse(cookieService.get("author")).role !== 'WRITER') || !authService.isAuthenticated()) {
+  if ((authService.isAuthenticated() && JSON.parse(cookieService.get("author")).role !== Role.WRITER) || !authService.isAuthenticated()) {
     router.navigate(['/']);
   }
 
diff --git a/src/app/models/role.ts b/src/app/models/role.ts
new file mode 100644
index 0000000..d08096b
--- /dev/null
+++ b/src/app/models/role.ts
@@ -0,0 +1,5 @@
+export enum Role {
+  WRITER = "WRITER",
+  READER = "READER",
+  ADMIN = "ADMIN",
+}
diff --git a/src/app/pages/admin-authors/admin-authors.component.ts b/src/app/pages/admin-authors/admin-authors.component.ts
index 8ef8ec8..ea5d7ea 100644
--- a/src/app/pages/admin-authors/admin-authors.component.ts
+++ b/src/app/pages/admin-authors/admin-authors.component.ts
@@ -39,8 +39,8 @@ export class AdminAuthorsComponent implements OnDestroy{
       next: (authors: Author[]) => {
         this.authors = authors;
       },
-      error: (error: Error) => {
-        this.failureMessage("Erreur", error.message)
+      error: (error) => {
+        this.failureMessage("Erreur", error.error.message)
       }
     })
   }
diff --git a/src/app/pages/home/home.component.ts b/src/app/pages/home/home.component.ts
index 7d72096..1aa49d1 100644
--- a/src/app/pages/home/home.component.ts
+++ b/src/app/pages/home/home.component.ts
@@ -45,7 +45,7 @@ export class HomeComponent implements OnDestroy {
           }
           return 0
         }),
-        error: (err) => console.error(err.message),
+        error: (err) => console.error(err.error.error.message),
       }));
   }
 
diff --git a/src/app/pages/login/login.component.ts b/src/app/pages/login/login.component.ts
index 6dc34bf..8825cf4 100644
--- a/src/app/pages/login/login.component.ts
+++ b/src/app/pages/login/login.component.ts
@@ -67,7 +67,7 @@ export class LoginComponent implements OnDestroy {
                 this.successMessage('Connecté avec succès', 'Heureux de vous revoir ' + this.actualAuthor?.name)
               });
             },
-            error: (err) => this.failureMessage('Erreur de connexion', err.message)
+            error: (err) => this.failureMessage('Erreur de connexion', err.error.message)
           })
       );
     } else {
diff --git a/src/app/pages/my-posts/my-posts.component.ts b/src/app/pages/my-posts/my-posts.component.ts
index 94932cc..18923f6 100644
--- a/src/app/pages/my-posts/my-posts.component.ts
+++ b/src/app/pages/my-posts/my-posts.component.ts
@@ -62,7 +62,7 @@ export class MyPostsComponent implements OnDestroy {
     if (!(this.authService.isSessionExpired()) && this.authService.isAuthenticated()) {
       this.authorService.getAuthorsPosts(this.actualAuthor?.id, this.authService.getAuthenticatedAuthorToken()).subscribe({
           next: posts => this.posts = posts,
-          error: error => this.failureMessage("Erreur", error.message),
+          error: error => this.failureMessage("Erreur", error.error.message),
         }
       )
     } else {
@@ -76,7 +76,7 @@ export class MyPostsComponent implements OnDestroy {
         this.updatePosts()
         this.successMessage("Post supprimé", "Ce post a été supprimé avec succès")
       },
-      error: error => this.failureMessage("Erreur", error.message),
+      error: error => this.failureMessage("Erreur", error.error.message),
     });
     this.closeDialog(this.deleteDialogVisibility, rowIndex)
   }
diff --git a/src/app/pages/new-post/new-post.component.ts b/src/app/pages/new-post/new-post.component.ts
index e33a27a..98c3cd6 100644
--- a/src/app/pages/new-post/new-post.component.ts
+++ b/src/app/pages/new-post/new-post.component.ts
@@ -88,7 +88,7 @@ export class NewPostComponent implements OnDestroy {
             });
           },
           error: (err) => {
-            this.failureMessage('Erreur', err.message);
+            this.failureMessage('Erreur', err.error.message);
           }
         })
       );
diff --git a/src/app/pages/post/post.component.html b/src/app/pages/post/post.component.html
index b1e6cf0..0f22b6a 100644
--- a/src/app/pages/post/post.component.html
+++ b/src/app/pages/post/post.component.html
@@ -23,7 +23,7 @@
             <p> Envoyé le {{ comment.commentDate | date: "dd/MM/yyyy à HH:mm" }}</p>
           }
           @if (actualAuthor) {
-            @if (comment.authorId === actualAuthor.id || actualAuthor.role === 'ADMIN') {
+            @if (comment.authorId === actualAuthor.id || actualAuthor.role === Role.ADMIN) {
               <p-button severity="danger" icon="pi pi-trash" (onClick)="setCommentDialogVisible(comment.id)"></p-button>
               <p-dialog [closable]="false" [modal]="true" header='Supprimer le commentaire ?' [visible]="commentDeleteDialogMap.get(comment.id) ?? false">
                 <div class="delete-dialog">
@@ -50,7 +50,7 @@
             <p> Envoyé le {{ comment.commentDate | date: "dd/MM/yyyy à HH:mm" }}</p>
           }
           @if (actualAuthor) {
-            @if (comment.authorId === actualAuthor.id || actualAuthor.role === 'ADMIN') {
+            @if (comment.authorId === actualAuthor.id || actualAuthor.role === Role.ADMIN) {
               <p-button severity="danger" icon="pi pi-trash" (onClick)="setCommentDialogVisible(comment.id)"></p-button>
               <p-dialog [closable]="false" [modal]="true" header='Supprimer le commentaire ?' [visible]="commentDeleteDialogMap.get(comment.id) ?? false">
                 <div class="delete-dialog">
diff --git a/src/app/pages/post/post.component.ts b/src/app/pages/post/post.component.ts
index 51610ab..07d87e2 100644
--- a/src/app/pages/post/post.component.ts
+++ b/src/app/pages/post/post.component.ts
@@ -16,6 +16,7 @@ import {CommentFormComponent} from '../../components/comment-form/comment-form.c
 import {Button} from 'primeng/button';
 import {DialogModule} from 'primeng/dialog';
 import {AuthService} from '../../auth.service';
+import {Role} from '../../models/role';
 
 @Component({
   selector: 'app-post',
@@ -73,7 +74,7 @@ export class PostComponent {
               });
               this.comments.forEach(comment => this.commentDeleteDialogMap.set(comment.id, false));
             },
-            error: err => this.failureMessage("Erreur", err.message)
+            error: err => this.failureMessage("Erreur", err.error.message)
           }));
       }
       if (this.concernedPost?.body) {
@@ -106,7 +107,7 @@ export class PostComponent {
             this.setCommentDialogHidden(comment.id);
             this.commentDeleteDialogMap.delete(comment.id);
           },
-          error: err => this.failureMessage("Erreur", err.message)
+          error: err => this.failureMessage("Erreur", err.error.message)
         })
       );
     }
@@ -142,4 +143,6 @@ export class PostComponent {
       closable: false
     });
   }
+
+  protected readonly Role = Role;
 }