diff --git a/composer.json b/composer.json
index b29b690..da2abde 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,8 @@
     },
     "autoload-dev": {
         "psr-4": {
-            "Tests\\": "tests/"
+            "Tests\\": "tests/",
+            "ProtoPhpGen\\": "tools/protoc-php-gen/src/"
         }
     },
     "config": {
diff --git a/config/routes.php b/config/routes.php
index 3dd8c31..39f3070 100644
--- a/config/routes.php
+++ b/config/routes.php
@@ -2,7 +2,9 @@
 
 declare(strict_types=1);
 
+use App\Application\Handlers\AuthHandler;
 use App\Application\Handlers\HandlerInterface;
+use App\Application\Handlers\HomeHandler;
 
 /**
  * WARNING: This file is automatically generated
@@ -19,24 +21,24 @@
     [
         'method' => 'POST',
         'path' => '/api/v1/auth/login',
-        'handler' => App\Application\Handlers\AuthHandler::class,
+        'handler' => AuthHandler::class,
     ],
     // AuthService.Logout
     [
         'method' => 'POST',
         'path' => '/api/v1/auth/logout',
-        'handler' => App\Application\Handlers\AuthHandler::class,
+        'handler' => AuthHandler::class,
     ],
     // AuthService.RefreshToken
     [
         'method' => 'POST',
         'path' => '/api/v1/auth/refresh',
-        'handler' => App\Application\Handlers\AuthHandler::class,
+        'handler' => AuthHandler::class,
     ],
     // HomeService.Home
     [
         'method' => 'GET',
         'path' => '/api/v1/home',
-        'handler' => App\Application\Handlers\HomeHandler::class,
-    ]
+        'handler' => HomeHandler::class,
+    ],
 ];
diff --git a/phpstan.neon b/phpstan.neon
index 845e563..2020803 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -6,3 +6,5 @@ parameters:
 		- tests
 		- config
 		- public
+	scanDirectories:
+		- tools/protoc-php-gen/src
diff --git a/src/Application/Handlers/AuthHandler.php b/src/Application/Handlers/AuthHandler.php
new file mode 100644
index 0000000..1e9d65b
--- /dev/null
+++ b/src/Application/Handlers/AuthHandler.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Application\Handlers;
+
+use App\Application\Http\JsonResponse;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+
+/**
+ * Authentication handler stub.
+ * TODO: Implement actual authentication logic.
+ */
+final readonly class AuthHandler extends AbstractJsonHandler
+{
+    public function __construct(
+        JsonResponse $jsonResponse,
+    ) {
+        parent::__construct($jsonResponse);
+    }
+
+    /**
+     * @throws \JsonException
+     */
+    public function handle(ServerRequestInterface $request): ResponseInterface
+    {
+        // TODO: Implement authentication endpoints (login, logout, refresh)
+        return $this->jsonResponse('{"error":"Not implemented"}', 501);
+    }
+}
diff --git a/src/Domain/User/User.php b/src/Domain/User/User.php
index 15a3272..e5b2377 100644
--- a/src/Domain/User/User.php
+++ b/src/Domain/User/User.php
@@ -8,7 +8,7 @@
 use ProtoPhpGen\Attributes\ProtoField;
 use ProtoPhpGen\Attributes\ProtoMapping;
 
-#[ProtoMapping(class: 'App\\Api\\V1\\User')]
+#[ProtoMapping(class: 'App\Api\V1\User')]
 final readonly class User implements Entity
 {
     public function __construct(