diff --git a/app/Events/MessageSent.php b/app/Events/MessageSent.php
new file mode 100644
index 0000000..9184139
--- /dev/null
+++ b/app/Events/MessageSent.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace App\Events;
+
+use App\Http\Resources\Messaging\MessageResource;
+use App\Models\Message;
+use Illuminate\Broadcasting\Channel;
+use Illuminate\Broadcasting\InteractsWithSockets;
+use Illuminate\Broadcasting\PrivateChannel;
+use Illuminate\Contracts\Broadcasting\ShouldBroadcast;
+use Illuminate\Foundation\Events\Dispatchable;
+use Illuminate\Queue\SerializesModels;
+
+class MessageSent implements ShouldBroadcast
+{
+    use Dispatchable, InteractsWithSockets, SerializesModels;
+
+    public $message;
+
+    /**
+     * Create a new event instance.
+     */
+    public function __construct(Message $message)
+    {
+        $this->message = $message;
+    }
+
+    /**
+     * Get the channels the event should broadcast on.
+     *
+     * @return array<int, \Illuminate\Broadcasting\Channel>
+     */
+    public function broadcastOn(): array
+    {
+        return [
+            new PrivateChannel('conversation.' . $this->message->conversation_id),
+        ];
+    }
+
+    /**
+     * Data to broadcast.
+     */
+    public function broadcastWith(): array
+    {
+        return [
+            'message' => new MessageResource($this->message->load('user')),
+        ];
+    }
+}
diff --git a/app/Http/Controllers/AuthController.php b/app/Http/Controllers/AuthController.php
index 9d3f5f3..7311a29 100644
--- a/app/Http/Controllers/AuthController.php
+++ b/app/Http/Controllers/AuthController.php
@@ -2,8 +2,8 @@
 
 namespace App\Http\Controllers;
 
-use App\Http\Requests\LoginRequest;
-use App\Http\Requests\RegisterRequest;
+use App\Http\Requests\Auth\LoginRequest;
+use App\Http\Requests\Auth\RegisterRequest;
 use App\Http\Requests\UpdateUserRequest;
 use App\Http\Resources\UserResource;
 use App\Models\User;
@@ -33,6 +33,7 @@ class AuthController extends Controller
 
         return response()->json([
             'user' => new UserResource($user),
+            'token' => $token,
         ], 201)->cookie('token', $token, 60 * 24 * 30);
     }
 
@@ -52,6 +53,7 @@ class AuthController extends Controller
 
         return response()->json([
             'user' => new UserResource($user),
+            'token' => $token,
         ])->cookie('token', $token, 60 * 24 * 30);
     }
 
diff --git a/app/Http/Controllers/ConversationController.php b/app/Http/Controllers/ConversationController.php
index fb46ec9..0b57e34 100644
--- a/app/Http/Controllers/ConversationController.php
+++ b/app/Http/Controllers/ConversationController.php
@@ -2,64 +2,96 @@
 
 namespace App\Http\Controllers;
 
+use App\Http\Requests\Messaging\ConversationRequest;
+use App\Http\Resources\Messaging\ConversationResource;
 use App\Models\Conversation;
 use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
 
 class ConversationController extends Controller
 {
     /**
      * Display a listing of the resource.
      */
-    public function index()
+    public function index(Request $request): AnonymousResourceCollection
     {
-        //
-    }
+        $conversations = $request->user()->conversations()
+            ->with(['users', 'latestMessage'])
+            ->latest()
+            ->get();
 
-    /**
-     * Show the form for creating a new resource.
-     */
-    public function create()
-    {
-        //
+        return ConversationResource::collection($conversations);
     }
 
     /**
      * Store a newly created resource in storage.
      */
-    public function store(Request $request)
+    public function store(ConversationRequest $request): ConversationResource
     {
-        //
+        $validated = $request->validated();
+        
+        $conversation = Conversation::create([
+            'label' => $validated['label'] ?? null,
+            'is_group' => $validated['is_group'] ?? false,
+        ]);
+
+        $participants = $validated['participants'];
+        if (!in_array($request->user()->id, $participants)) {
+            $participants[] = $request->user()->id;
+        }
+
+        $conversation->users()->sync($participants);
+
+        return new ConversationResource($conversation->load('users'));
     }
 
     /**
      * Display the specified resource.
      */
-    public function show(Conversation $conversation)
+    public function show(Request $request, Conversation $conversation): ConversationResource
     {
-        //
-    }
+        // Check if user is participant
+        if (!$conversation->participants()->where('user_id', $request->user()->id)->exists()) {
+            abort(403);
+        }
 
-    /**
-     * Show the form for editing the specified resource.
-     */
-    public function edit(Conversation $conversation)
-    {
-        //
+        return new ConversationResource($conversation->load(['users', 'latestMessage']));
     }
 
     /**
      * Update the specified resource in storage.
      */
-    public function update(Request $request, Conversation $conversation)
+    public function update(ConversationRequest $request, Conversation $conversation): ConversationResource
     {
-        //
+        if (!$conversation->participants()->where('user_id', $request->user()->id)->exists()) {
+            abort(403);
+        }
+
+        $validated = $request->validated();
+        
+        $conversation->update([
+            'label' => $validated['label'] ?? $conversation->label,
+            'is_group' => $validated['is_group'] ?? $conversation->is_group,
+        ]);
+
+        if (isset($validated['participants'])) {
+             $conversation->users()->sync($validated['participants']);
+        }
+
+        return new ConversationResource($conversation->load('users'));
     }
 
     /**
      * Remove the specified resource from storage.
      */
-    public function destroy(Conversation $conversation)
+    public function destroy(Request $request, Conversation $conversation)
     {
-        //
+        if (!$conversation->participants()->where('user_id', $request->user()->id)->exists()) {
+            abort(403);
+        }
+
+        $conversation->delete();
+
+        return response()->noContent();
     }
 }
diff --git a/app/Http/Controllers/MessageController.php b/app/Http/Controllers/MessageController.php
index 7b7b6b1..9559490 100644
--- a/app/Http/Controllers/MessageController.php
+++ b/app/Http/Controllers/MessageController.php
@@ -2,64 +2,88 @@
 
 namespace App\Http\Controllers;
 
+use App\Http\Requests\Messaging\MessageRequest;
+use App\Http\Resources\Messaging\MessageResource;
+use App\Models\Conversation;
 use App\Models\Message;
 use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
 
 class MessageController extends Controller
 {
     /**
-     * Display a listing of the resource.
+     * Display a listing of the resource for a conversation.
      */
-    public function index()
+    public function index(Request $request, Conversation $conversation): AnonymousResourceCollection
     {
-        //
-    }
+        if (!$conversation->participants()->where('user_id', $request->user()->id)->exists()) {
+            abort(403);
+        }
 
-    /**
-     * Show the form for creating a new resource.
-     */
-    public function create()
-    {
-        //
+        $messages = $conversation->messages()
+            ->with('user')
+            ->oldest()
+            ->get();
+
+        return MessageResource::collection($messages);
     }
 
     /**
      * Store a newly created resource in storage.
      */
-    public function store(Request $request)
+    public function store(MessageRequest $request, Conversation $conversation): MessageResource
     {
-        //
-    }
+        if (!$conversation->participants()->where('user_id', $request->user()->id)->exists()) {
+            abort(403);
+        }
 
-    /**
-     * Display the specified resource.
-     */
-    public function show(Message $message)
-    {
-        //
-    }
+        $validated = $request->validated();
+        
+        $user = $request->user();
+        
+        $message = $conversation->messages()->create([
+            'user_id' => $user->id,
+            'sender_name' => $user->name,
+            'sender_avatar_url' => $user->avatar_url,
+            'body' => $validated['body'],
+        ]);
 
-    /**
-     * Show the form for editing the specified resource.
-     */
-    public function edit(Message $message)
-    {
-        //
-    }
+        broadcast(new \App\Events\MessageSent($message))->toOthers();
 
-    /**
-     * Update the specified resource in storage.
-     */
-    public function update(Request $request, Message $message)
-    {
-        //
+        return new MessageResource($message->load('user'));
     }
 
     /**
      * Remove the specified resource from storage.
      */
-    public function destroy(Message $message)
+    public function destroy(Request $request, Message $message)
     {
-        //
+        if ($message->user_id !== $request->user()->id) {
+            abort(403);
+        }
+
+        $message->delete();
+
+        return response()->noContent();
+    }
+
+    /**
+     * Mark a message as read.
+     */
+    public function markAsRead(Request $request, Message $message)
+    {
+        $conversation = $message->conversation;
+        if (!$conversation->participants()->where('user_id', $request->user()->id)->exists()) {
+            abort(403);
+        }
+
+        if ($message->user_id === $request->user()->id) {
+            // Can't mark your own message as read by you (well you could but it's redundant)
+            // But let's say anyone in the conversation can mark any message as read.
+        }
+
+        $message->update(['read_at' => now()]);
+
+        return new MessageResource($message->load('user'));
     }
 }
diff --git a/app/Http/Controllers/UserController.php b/app/Http/Controllers/UserController.php
new file mode 100644
index 0000000..a8dc2ce
--- /dev/null
+++ b/app/Http/Controllers/UserController.php
@@ -0,0 +1,22 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Models\User;
+use App\Http\Resources\UserResource;
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
+
+class UserController extends Controller
+{
+    /**
+     * Display a listing of all users except the authenticated one.
+     */
+    public function index(Request $request): AnonymousResourceCollection
+    {
+        // On retourne tous les utilisateurs sauf soi-même pour faciliter la création de conversations
+        $users = User::all();
+
+        return UserResource::collection($users);
+    }
+}
diff --git a/app/Http/Requests/LoginRequest.php b/app/Http/Requests/Auth/LoginRequest.php
similarity index 94%
rename from app/Http/Requests/LoginRequest.php
rename to app/Http/Requests/Auth/LoginRequest.php
index 422ec00..271dc0b 100644
--- a/app/Http/Requests/LoginRequest.php
+++ b/app/Http/Requests/Auth/LoginRequest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace App\Http\Requests;
+namespace App\Http\Requests\Auth;
 
 use Illuminate\Foundation\Http\FormRequest;
 
diff --git a/app/Http/Requests/RegisterRequest.php b/app/Http/Requests/Auth/RegisterRequest.php
similarity index 96%
rename from app/Http/Requests/RegisterRequest.php
rename to app/Http/Requests/Auth/RegisterRequest.php
index 1b4b361..53beb43 100644
--- a/app/Http/Requests/RegisterRequest.php
+++ b/app/Http/Requests/Auth/RegisterRequest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace App\Http\Requests;
+namespace App\Http\Requests\Auth;
 
 use Illuminate\Foundation\Http\FormRequest;
 
diff --git a/app/Http/Requests/Messaging/ConversationRequest.php b/app/Http/Requests/Messaging/ConversationRequest.php
new file mode 100644
index 0000000..613ede6
--- /dev/null
+++ b/app/Http/Requests/Messaging/ConversationRequest.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace App\Http\Requests\Messaging;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+class ConversationRequest extends FormRequest
+{
+    /**
+     * Determine if the user is authorized to make this request.
+     */
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /**
+     * Get the validation rules that apply to the request.
+     *
+     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array<mixed>|string>
+     */
+    public function rules(): array
+    {
+        return [
+            'label' => 'nullable|string|max:255',
+            'is_group' => 'boolean',
+            'participants' => 'required|array|min:1',
+            'participants.*' => 'exists:users,id',
+        ];
+    }
+}
diff --git a/app/Http/Requests/Messaging/MessageRequest.php b/app/Http/Requests/Messaging/MessageRequest.php
new file mode 100644
index 0000000..4974de9
--- /dev/null
+++ b/app/Http/Requests/Messaging/MessageRequest.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Http\Requests\Messaging;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+class MessageRequest extends FormRequest
+{
+    /**
+     * Determine if the user is authorized to make this request.
+     */
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /**
+     * Get the validation rules that apply to the request.
+     *
+     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array<mixed>|string>
+     */
+    public function rules(): array
+    {
+        return [
+            'body' => 'required|string',
+        ];
+    }
+}
diff --git a/app/Http/Resources/Messaging/ConversationResource.php b/app/Http/Resources/Messaging/ConversationResource.php
new file mode 100644
index 0000000..3daabe3
--- /dev/null
+++ b/app/Http/Resources/Messaging/ConversationResource.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Http\Resources\Messaging;
+
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\JsonResource;
+use App\Http\Resources\UserResource;
+
+class ConversationResource extends JsonResource
+{
+    /**
+     * Transform the resource into an array.
+     *
+     * @return array<string, mixed>
+     */
+    public function toArray(Request $request): array
+    {
+        return [
+            'id' => $this->id,
+            'label' => $this->label,
+            'isGroup' => $this->is_group,
+            'participants' => UserResource::collection($this->whenLoaded('users')),
+            'lastMessage' => new MessageResource($this->whenLoaded('latestMessage')),
+            'createdAt' => $this->created_at,
+            'updatedAt' => $this->updated_at,
+        ];
+    }
+}
diff --git a/app/Http/Resources/Messaging/MessageResource.php b/app/Http/Resources/Messaging/MessageResource.php
new file mode 100644
index 0000000..3998fb7
--- /dev/null
+++ b/app/Http/Resources/Messaging/MessageResource.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Http\Resources\Messaging;
+
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\JsonResource;
+use App\Http\Resources\UserResource;
+
+class MessageResource extends JsonResource
+{
+    /**
+     * Transform the resource into an array.
+     *
+     * @return array<string, mixed>
+     */
+    public function toArray(Request $request): array
+    {
+        return [
+            'senderId' => $this->user_id,
+            'senderName' => $this->sender_name,
+            'senderAvatarUrl' => $this->sender_avatar_url,
+            'body' => $this->body,
+            'readAt' => $this->read_at,
+            'createdAt' => $this->created_at,
+        ];
+    }
+}
diff --git a/app/Http/Resources/UserResource.php b/app/Http/Resources/UserResource.php
index 5af57f6..ad9a082 100644
--- a/app/Http/Resources/UserResource.php
+++ b/app/Http/Resources/UserResource.php
@@ -16,9 +16,10 @@ class UserResource extends JsonResource
     public function toArray(Request $request): array
     {
         return [
+            'id' => $this->id,
             'name' => $this->name,
             'email' => $this->email,
-            'avatar_url' => $this->avatar_url ? asset(Storage::url($this->avatar_url)) : null,
+            'avatarUrl' => $this->avatar_url ? asset(Storage::url($this->avatar_url)) : null,
         ];
     }
 }
diff --git a/app/Http/Resources/todoResource.php b/app/Http/Resources/todoResource.php
index 400a66a..0b9442f 100644
--- a/app/Http/Resources/todoResource.php
+++ b/app/Http/Resources/todoResource.php
@@ -15,8 +15,8 @@ class todoResource extends JsonResource
             'name' => $this->name,
             'status' => $this->status,
             'description' => $this->description,
-            'image_url' => $this->image_url ? asset(Storage::url($this->image_url)): null,
-            'due_date' => $this->due_date,
+            'imageUrl' => $this->image_url ? asset(Storage::url($this->image_url)): null,
+            'dueDate' => $this->due_date,
             'priority' => $this->priority,
             'created_at' => $this->created_at,
             'updated_at' => $this->updated_at,
diff --git a/app/Models/Conversation.php b/app/Models/Conversation.php
index 3c7c390..2764790 100644
--- a/app/Models/Conversation.php
+++ b/app/Models/Conversation.php
@@ -35,6 +35,11 @@ class Conversation extends Model
         return $this->hasMany(Message::class);
     }
 
+    public function latestMessage(): \Illuminate\Database\Eloquent\Relations\HasOne
+    {
+        return $this->hasOne(Message::class)->latestOfMany();
+    }
+
     public function users(): BelongsToMany
     {
         return $this->belongsToMany(User::class, 'participants')
diff --git a/app/Models/User.php b/app/Models/User.php
index b247ab4..63ea515 100644
--- a/app/Models/User.php
+++ b/app/Models/User.php
@@ -57,6 +57,18 @@ class User extends Authenticatable implements FilamentUser
         return $this->hasMany(Todo::class);
     }
 
+    public function conversations(): \Illuminate\Database\Eloquent\Relations\BelongsToMany
+    {
+        return $this->belongsToMany(Conversation::class, 'participants')
+            ->withTimestamps()
+            ->using(Participant::class);
+    }
+
+    public function messages(): HasMany
+    {
+        return $this->hasMany(Message::class);
+    }
+
     public function isAdmin()
     {
         return true;
diff --git a/routes/api.php b/routes/api.php
index 111eb84..b3f0ed1 100644
--- a/routes/api.php
+++ b/routes/api.php
@@ -21,3 +21,14 @@ Route::middleware('auth:sanctum')->prefix('todos')->group(function (): void {
     Route::patch('/{todo}', [todoController::class, 'update']);
     Route::delete('/{todo}', [todoController::class, 'destroy']);
 });
+
+Route::middleware('auth:sanctum')->group(function (): void {
+    Route::get('users', [\App\Http\Controllers\UserController::class, 'index']);
+    Route::apiResource('conversations', \App\Http\Controllers\ConversationController::class);
+    
+    Route::get('conversations/{conversation}/messages', [\App\Http\Controllers\MessageController::class, 'index']);
+    Route::post('conversations/{conversation}/messages', [\App\Http\Controllers\MessageController::class, 'store']);
+    
+    Route::delete('messages/{message}', [\App\Http\Controllers\MessageController::class, 'destroy']);
+    Route::patch('messages/{message}/read', [\App\Http\Controllers\MessageController::class, 'markAsRead']);
+});
diff --git a/routes/channels.php b/routes/channels.php
index df2ad28..5f83b17 100644
--- a/routes/channels.php
+++ b/routes/channels.php
@@ -3,5 +3,12 @@
 use Illuminate\Support\Facades\Broadcast;
 
 Broadcast::channel('App.Models.User.{id}', function ($user, $id) {
-    return (int) $user->id === (int) $id;
+    return (string) $user->id === (string) $id;
+});
+
+Broadcast::channel('conversation.{conversationId}', function ($user, $conversationId) {
+    return \App\Models\Conversation::find($conversationId)
+        ?->participants()
+        ->where('user_id', $user->id)
+        ->exists();
 });