diff --git a/app/Exceptions/BadRequestException.php b/app/Exceptions/BadRequestException.php
new file mode 100644
index 0000000..ebf6385
--- /dev/null
+++ b/app/Exceptions/BadRequestException.php
@@ -0,0 +1,5 @@
+<?php
+
+namespace App\Exceptions;
+
+class BadRequestException extends \RuntimeException {}
diff --git a/app/Node/NodeController.php b/app/Node/NodeController.php
index 20d534f..bb3aa30 100644
--- a/app/Node/NodeController.php
+++ b/app/Node/NodeController.php
@@ -2,6 +2,7 @@
 
 namespace App\Node;
 
+use App\Exceptions\BadRequestException;
 use App\Node\UseCases\BulkCreateNodesRequest;
 use App\Node\NodeRepository;
 use App\Node\UseCases\BulkCreateNodes;
@@ -47,17 +48,10 @@ class NodeController
         CreateNode $createNodeUseCase,
     ): Response {
         $data = json_decode((string) $request->getBody(), true) ?? [];
-        $title = $data['title'] ?? '';
 
-        if (empty($title)) {
-            $response->getBody()->write(json_encode(['error' => 'Title is required']));
-            return $response->withStatus(400)->withHeader('Content-Type', 'application/json');
-        }
-
-        $textId = (int) ($data['textId'] ?? 0);
-        $parentNodeId = isset($data['parentNodeId']) && $data['parentNodeId'] !== null
-            ? (int) $data['parentNodeId']
-            : null;
+        $textId = isset($data['textId']) ? (int) $data['textId'] : null;
+        $title = $data['title'] ?? null;
+        $parentNodeId = isset($data['parentNodeId']) ? (int) $data['parentNodeId'] : null;
 
         try {
             $node = $createNodeUseCase->execute(new CreateNodeRequest(
@@ -65,6 +59,9 @@ class NodeController
                 title: $title,
                 parentNodeId: $parentNodeId,
             ));
+        } catch (BadRequestException $e) {
+            $response->getBody()->write(json_encode(['error' => $e->getMessage()]));
+            return $response->withStatus(400)->withHeader('Content-Type', 'application/json');
         } catch (DomainException $e) {
             $response->getBody()->write(json_encode(['error' => $e->getMessage()]));
             return $response->withStatus(404)->withHeader('Content-Type', 'application/json');
@@ -85,25 +82,10 @@ class NodeController
     ): Response {
         $data = json_decode((string) $request->getBody(), true) ?? [];
 
-        $titlePrefix = trim($data['titlePrefix'] ?? '');
-        if ($titlePrefix === '') {
-            $response->getBody()->write(json_encode(['error' => 'Title prefix is required']));
-            return $response->withStatus(400)->withHeader('Content-Type', 'application/json');
-        }
-
-        $count = isset($data['count']) ? (int) $data['count'] : 0;
-        if ($count < 1) {
-            $response->getBody()->write(json_encode(['error' => 'Count must be at least 1']));
-            return $response->withStatus(400)->withHeader('Content-Type', 'application/json');
-        }
-
-        if (!isset($data['parentNodeId']) || $data['parentNodeId'] === null) {
-            $response->getBody()->write(json_encode(['error' => 'parentNodeId is required']));
-            return $response->withStatus(400)->withHeader('Content-Type', 'application/json');
-        }
-
-        $textId = (int) ($data['textId'] ?? 0);
-        $parentNodeId = (int) $data['parentNodeId'];
+        $textId = isset($data['textId']) ? (int) $data['textId'] : null;
+        $parentNodeId = isset($data['parentNodeId']) ? (int) $data['parentNodeId'] : null;
+        $titlePrefix = isset($data['titlePrefix']) ? (string) $data['titlePrefix'] : null;
+        $count = isset($data['count']) ? (int) $data['count'] : null;
 
         try {
             $nodes = $bulkCreateNodesUseCase->execute(new BulkCreateNodesRequest(
@@ -112,6 +94,9 @@ class NodeController
                 titlePrefix: $titlePrefix,
                 count: $count,
             ));
+        } catch (BadRequestException $e) {
+            $response->getBody()->write(json_encode(['error' => $e->getMessage()]));
+            return $response->withStatus(400)->withHeader('Content-Type', 'application/json');
         } catch (DomainException $e) {
             $response->getBody()->write(json_encode(['error' => $e->getMessage()]));
             return $response->withStatus(404)->withHeader('Content-Type', 'application/json');
diff --git a/app/Node/UseCases/BulkCreateNodes.php b/app/Node/UseCases/BulkCreateNodes.php
index 1ca322d..f2c39ad 100644
--- a/app/Node/UseCases/BulkCreateNodes.php
+++ b/app/Node/UseCases/BulkCreateNodes.php
@@ -2,6 +2,7 @@
 
 namespace App\Node\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\Node\CreateNodeDto;
 use App\Node\Node;
 use App\Node\NodeRepository;
@@ -17,10 +18,31 @@ class BulkCreateNodes
 
     /**
      * @return Node[]
+     * @throws BadRequestException
      * @throws DomainException
      */
     public function execute(BulkCreateNodesRequest $request): array
     {
+        if ($request->textId === null) {
+            throw new BadRequestException('textId is required');
+        }
+
+        if ($request->parentNodeId === null) {
+            throw new BadRequestException('parentNodeId is required');
+        }
+
+        if ($request->titlePrefix === null) {
+            throw new BadRequestException('titlePrefix is required');
+        }
+
+        if ($request->count === null) {
+            throw new BadRequestException('count is required');
+        }
+
+        if ($request->count < 1) {
+            throw new BadRequestException('count must be at least 1');
+        }
+
         $text = $this->textRepo->find($request->textId);
         if ($text === null) {
             throw new DomainException("Text with id: {$request->textId} doesnt exist");
diff --git a/app/Node/UseCases/BulkCreateNodesRequest.php b/app/Node/UseCases/BulkCreateNodesRequest.php
index 45b94be..1682faf 100644
--- a/app/Node/UseCases/BulkCreateNodesRequest.php
+++ b/app/Node/UseCases/BulkCreateNodesRequest.php
@@ -5,9 +5,9 @@ namespace App\Node\UseCases;
 class BulkCreateNodesRequest
 {
     public function __construct(
-        public int $textId,
-        public int $parentNodeId,
-        public string $titlePrefix,
-        public int $count,
+        public ?int $textId,
+        public ?int $parentNodeId,
+        public ?string $titlePrefix,
+        public ?int $count,
     ) {}
 }
diff --git a/app/Node/UseCases/CreateNode.php b/app/Node/UseCases/CreateNode.php
index dcb8afa..5819205 100644
--- a/app/Node/UseCases/CreateNode.php
+++ b/app/Node/UseCases/CreateNode.php
@@ -2,6 +2,7 @@
 
 namespace App\Node\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\Node\Node;
 use App\Node\CreateNodeDto;
 use App\Node\NodeRepository;
@@ -16,10 +17,19 @@ class CreateNode
     ) {}
 
     /**
+     * @throws BadRequestException
      * @throws DomainException
      */
     public function execute(CreateNodeRequest $request): Node
     {
+        if ($request->textId === null) {
+            throw new BadRequestException('textId is required');
+        }
+
+        if ($request->title === null) {
+            throw new BadRequestException('title is required');
+        }
+
         $textId = $request->textId;
         $text = $this->textRepo->find($textId);
         if ($text === null) {
diff --git a/app/Node/UseCases/CreateNodeRequest.php b/app/Node/UseCases/CreateNodeRequest.php
index 700a824..521fbbf 100644
--- a/app/Node/UseCases/CreateNodeRequest.php
+++ b/app/Node/UseCases/CreateNodeRequest.php
@@ -5,8 +5,8 @@ namespace App\Node\UseCases;
 class CreateNodeRequest
 {
     public function __construct(
-        public int $textId,
-        public string $title,
+        public ?int $textId,
+        public ?string $title,
         public ?int $parentNodeId,
     ) {}
 }
diff --git a/app/Plan/UseCases/CreatePlan.php b/app/Plan/UseCases/CreatePlan.php
index cf9a3d2..edc65d2 100644
--- a/app/Plan/UseCases/CreatePlan.php
+++ b/app/Plan/UseCases/CreatePlan.php
@@ -2,6 +2,7 @@
 
 namespace App\Plan\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\Node\NodeRepository;
 use App\Plan\CreatePlanDto;
 use App\Plan\Plan;
@@ -24,10 +25,23 @@ class CreatePlan
     ) {}
 
     /**
+     * @throws BadRequestException
      * @throws DomainException
      */
     public function execute(CreatePlanRequest $request): Plan
     {
+        if ($request->userId === null) {
+            throw new BadRequestException('userId is required');
+        }
+
+        if ($request->textId === null) {
+            throw new BadRequestException('textId is required');
+        }
+
+        if ($request->name === null) {
+            throw new BadRequestException('name is required');
+        }
+
         $userId = $request->userId;
         $user = $this->userRepo->find($userId);
         if ($user === null) {
diff --git a/app/Plan/UseCases/CreatePlanRequest.php b/app/Plan/UseCases/CreatePlanRequest.php
index 2af3e1e..d9e0669 100644
--- a/app/Plan/UseCases/CreatePlanRequest.php
+++ b/app/Plan/UseCases/CreatePlanRequest.php
@@ -5,8 +5,8 @@ namespace App\Plan\UseCases;
 class CreatePlanRequest
 {
     public function __construct(
-        public int $userId,
-        public int $textId,
-        public string $name,
+        public ?int $userId,
+        public ?int $textId,
+        public ?string $name,
     ) {}
 }
diff --git a/app/ScheduledNode/UseCases/CreateScheduledNode.php b/app/ScheduledNode/UseCases/CreateScheduledNode.php
index a279f62..9a82b10 100644
--- a/app/ScheduledNode/UseCases/CreateScheduledNode.php
+++ b/app/ScheduledNode/UseCases/CreateScheduledNode.php
@@ -2,6 +2,7 @@
 
 namespace App\ScheduledNode\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\Plan\PlanRepository;
 use App\ScheduledNode\ScheduledNode;
 use App\ScheduledNode\CreateScheduledNodeDto;
@@ -15,9 +16,21 @@ class CreateScheduledNode
         private PlanRepository $planRepo,
     ) {}
 
+    /**
+     * @throws BadRequestException
+     * @throws DomainException
+     */
     public function execute(
         CreateScheduledNodeRequest $request
     ): ScheduledNode {
+        if ($request->date === null) {
+            throw new BadRequestException('date is required');
+        }
+
+        if ($request->planId === null) {
+            throw new BadRequestException('planId is required');
+        }
+
         $id = $request->planId;
         $plan = $this->planRepo->find($id);
         if ($plan === null) {
diff --git a/app/ScheduledNode/UseCases/CreateScheduledNodeRequest.php b/app/ScheduledNode/UseCases/CreateScheduledNodeRequest.php
index 153dddc..1fb9c80 100644
--- a/app/ScheduledNode/UseCases/CreateScheduledNodeRequest.php
+++ b/app/ScheduledNode/UseCases/CreateScheduledNodeRequest.php
@@ -7,7 +7,7 @@ use DateTimeImmutable;
 class CreateScheduledNodeRequest
 {
     public function __construct(
-        public DateTimeImmutable $date,
-        public int $planId,
+        public ?DateTimeImmutable $date,
+        public ?int $planId,
     ) {}
 }
diff --git a/app/Text/TextController.php b/app/Text/TextController.php
index c608018..3834f32 100644
--- a/app/Text/TextController.php
+++ b/app/Text/TextController.php
@@ -2,6 +2,7 @@
 
 namespace App\Text;
 
+use App\Exceptions\BadRequestException;
 use App\Text\TextRepository;
 use App\Text\UseCases\CreateText;
 use App\Text\UseCases\CreateTextRequest;
@@ -50,21 +51,21 @@ class TextController
         CreateText $createTextUseCase,
     ): Response {
         $data = $request->getParsedBody();
-        $name = $data['name'] ?? '';
+        $name = $data['name'] ?? null;
 
-        if (!empty($name)) {
+        try {
             $text = $createTextUseCase->execute(new CreateTextRequest(
                 name: $name,
             ));
-
-            $response->getBody()->write(json_encode([
-                'id' => $text->getId(),
-                'name' => $text->getName(),
-            ]));
-            return $response->withHeader('Content-Type', 'application/json');
+        } catch (BadRequestException $e) {
+            $response->getBody()->write(json_encode(['error' => $e->getMessage()]));
+            return $response->withStatus(400)->withHeader('Content-Type', 'application/json');
         }
 
-        $response->getBody()->write(json_encode(['error' => 'Name is required']));
-        return $response->withStatus(400);
+        $response->getBody()->write(json_encode([
+            'id' => $text->getId(),
+            'name' => $text->getName(),
+        ]));
+        return $response->withHeader('Content-Type', 'application/json');
     }
 }
diff --git a/app/Text/UseCases/CreateText.php b/app/Text/UseCases/CreateText.php
index bf4715b..a976997 100644
--- a/app/Text/UseCases/CreateText.php
+++ b/app/Text/UseCases/CreateText.php
@@ -2,6 +2,7 @@
 
 namespace App\Text\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\Text\Text;
 use App\Text\CreateTextDto;
 use App\Text\TextRepository;
@@ -15,8 +16,15 @@ class CreateText
         private NodeRepository $nodeRepo,
     ) {}
 
+    /**
+     * @throws BadRequestException
+     */
     public function execute(CreateTextRequest $request): Text
     {
+        if ($request->name === null) {
+            throw new BadRequestException('name is required');
+        }
+
         $text = $this->textRepo->create(new CreateTextDto(
             name: $request->name,
         ));
diff --git a/app/Text/UseCases/CreateTextRequest.php b/app/Text/UseCases/CreateTextRequest.php
index 9ccb2c6..3a6c6a4 100644
--- a/app/Text/UseCases/CreateTextRequest.php
+++ b/app/Text/UseCases/CreateTextRequest.php
@@ -5,6 +5,6 @@ namespace App\Text\UseCases;
 class CreateTextRequest
 {
     public function __construct(
-        public string $name,
+        public ?string $name,
     ) {}
 }
diff --git a/app/User/UseCases/CreateUser.php b/app/User/UseCases/CreateUser.php
index b59966f..cc5ffc0 100644
--- a/app/User/UseCases/CreateUser.php
+++ b/app/User/UseCases/CreateUser.php
@@ -2,6 +2,7 @@
 
 namespace App\User\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\User\UserRepository;
 use App\ValueObjects\EmailAddress;
 
@@ -11,8 +12,15 @@ class CreateUser
         private UserRepository $userRepo,
     ) {}
 
+    /**
+     * @throws BadRequestException
+     */
     public function execute(CreateUserRequest $dto): void
     {
+        if ($dto->email === null) {
+            throw new BadRequestException('email is required');
+        }
+
         $this->userRepo->create(new CreateUserDto(
             email: new EmailAddress($dto->email),
         ));
diff --git a/app/User/UseCases/CreateUserRequest.php b/app/User/UseCases/CreateUserRequest.php
index 93a3102..7c48913 100644
--- a/app/User/UseCases/CreateUserRequest.php
+++ b/app/User/UseCases/CreateUserRequest.php
@@ -5,6 +5,6 @@ namespace App\User\UseCases;
 class CreateUserRequest
 {
     public function __construct(
-        public string $email,
+        public ?string $email,
     ) {}
 }
diff --git a/tests/Unit/Node/UseCases/BulkCreateNodesTest.php b/tests/Unit/Node/UseCases/BulkCreateNodesTest.php
index b3f6240..3fd3452 100644
--- a/tests/Unit/Node/UseCases/BulkCreateNodesTest.php
+++ b/tests/Unit/Node/UseCases/BulkCreateNodesTest.php
@@ -2,6 +2,7 @@
 
 namespace Tests\Unit\Node\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\Node\CreateNodeDto;
 use App\Node\Node;
 use App\Node\UseCases\BulkCreateNodes;
@@ -131,4 +132,69 @@ class BulkCreateNodesTest extends TestCase
             count: 5,
         ));
     }
+
+    public function test_throws_if_text_id_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('textId is required');
+
+        $this->useCase->execute(new BulkCreateNodesRequest(
+            textId: null,
+            parentNodeId: $this->parentNode->getId(),
+            titlePrefix: 'Page',
+            count: 5,
+        ));
+    }
+
+    public function test_throws_if_parent_node_id_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('parentNodeId is required');
+
+        $this->useCase->execute(new BulkCreateNodesRequest(
+            textId: 0,
+            parentNodeId: null,
+            titlePrefix: 'Page',
+            count: 5,
+        ));
+    }
+
+    public function test_throws_if_title_prefix_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('titlePrefix is required');
+
+        $this->useCase->execute(new BulkCreateNodesRequest(
+            textId: 0,
+            parentNodeId: $this->parentNode->getId(),
+            titlePrefix: null,
+            count: 5,
+        ));
+    }
+
+    public function test_throws_if_count_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('count is required');
+
+        $this->useCase->execute(new BulkCreateNodesRequest(
+            textId: 0,
+            parentNodeId: $this->parentNode->getId(),
+            titlePrefix: 'Page',
+            count: null,
+        ));
+    }
+
+    public function test_throws_if_count_is_less_than_one(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('count must be at least 1');
+
+        $this->useCase->execute(new BulkCreateNodesRequest(
+            textId: 0,
+            parentNodeId: $this->parentNode->getId(),
+            titlePrefix: 'Page',
+            count: 0,
+        ));
+    }
 }
diff --git a/tests/Unit/Node/UseCases/CreateNodeTest.php b/tests/Unit/Node/UseCases/CreateNodeTest.php
index 68d4dfa..5b9226e 100644
--- a/tests/Unit/Node/UseCases/CreateNodeTest.php
+++ b/tests/Unit/Node/UseCases/CreateNodeTest.php
@@ -2,6 +2,7 @@
 
 namespace Tests\Unit\Node\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\Node\Node;
 use App\Node\NodeRepository;
 use App\Node\UseCases\CreateNode;
@@ -111,4 +112,28 @@ class CreateNodeTest extends TestCase
             parentNodeId: null,
         ));
     }
+
+    public function test_throws_if_text_id_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('textId is required');
+
+        $this->useCase->execute(new CreateNodeRequest(
+            textId: null,
+            title: 'test',
+            parentNodeId: null,
+        ));
+    }
+
+    public function test_throws_if_title_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('title is required');
+
+        $this->useCase->execute(new CreateNodeRequest(
+            textId: 0,
+            title: null,
+            parentNodeId: null,
+        ));
+    }
 }
diff --git a/tests/Unit/Plan/UseCases/CreatePlanTest.php b/tests/Unit/Plan/UseCases/CreatePlanTest.php
index 32f9162..26af21d 100644
--- a/tests/Unit/Plan/UseCases/CreatePlanTest.php
+++ b/tests/Unit/Plan/UseCases/CreatePlanTest.php
@@ -2,6 +2,7 @@
 
 namespace Tests\Unit\Plan\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\Node\CreateNodeDto;
 use App\Plan\UseCases\CreatePlan;
 use App\Plan\UseCases\CreatePlanRequest;
@@ -125,4 +126,40 @@ class CreatePlanTest extends TestCase
             $this->scheduledNodeRepo->getNumberOfTimesCreateCalled()
         );
     }
+
+    public function test_throws_if_user_id_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('userId is required');
+
+        $this->useCase->execute(new CreatePlanRequest(
+            userId: null,
+            name: 'testPlan',
+            textId: 0,
+        ));
+    }
+
+    public function test_throws_if_text_id_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('textId is required');
+
+        $this->useCase->execute(new CreatePlanRequest(
+            userId: 0,
+            name: 'testPlan',
+            textId: null,
+        ));
+    }
+
+    public function test_throws_if_name_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('name is required');
+
+        $this->useCase->execute(new CreatePlanRequest(
+            userId: 0,
+            name: null,
+            textId: 0,
+        ));
+    }
 }
diff --git a/tests/Unit/ScheduledNode/UseCases/CreateScheduledNodeTest.php b/tests/Unit/ScheduledNode/UseCases/CreateScheduledNodeTest.php
index 43617bd..3350a81 100644
--- a/tests/Unit/ScheduledNode/UseCases/CreateScheduledNodeTest.php
+++ b/tests/Unit/ScheduledNode/UseCases/CreateScheduledNodeTest.php
@@ -2,6 +2,7 @@
 
 namespace Tests\Unit\ScheduledNode\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\Plan\CreatePlanDto;
 use App\Plan\Plan;
 use App\ScheduledNode\ScheduledNode;
@@ -75,4 +76,30 @@ class CreateScheduledNodeTest extends TestCase
             )
         );
     }
+
+    public function test_throws_if_date_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('date is required');
+
+        $this->useCase->execute(
+            new CreateScheduledNodeRequest(
+                date: null,
+                planId: 0,
+            )
+        );
+    }
+
+    public function test_throws_if_plan_id_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('planId is required');
+
+        $this->useCase->execute(
+            new CreateScheduledNodeRequest(
+                date: new DateTimeImmutable('now'),
+                planId: null,
+            )
+        );
+    }
 }
diff --git a/tests/Unit/Text/UseCases/CreateTextTest.php b/tests/Unit/Text/UseCases/CreateTextTest.php
index 8b9cb56..279d6ab 100644
--- a/tests/Unit/Text/UseCases/CreateTextTest.php
+++ b/tests/Unit/Text/UseCases/CreateTextTest.php
@@ -2,6 +2,7 @@
 
 namespace Tests\Unit\Text\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\Text\Text;
 use App\Text\TextRepository;
 use App\Text\UseCases\CreateText;
@@ -51,4 +52,14 @@ class CreateTextTest extends TestCase
         $this->assertEquals('my text', $rootNode->getTitle());
         $this->assertNull($rootNode->getParentNode());
     }
+
+    public function test_throws_if_name_is_null(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('name is required');
+
+        $this->useCase->execute(new CreateTextRequest(
+            name: null,
+        ));
+    }
 }
diff --git a/tests/Unit/User/UseCases/CreateUserTest.php b/tests/Unit/User/UseCases/CreateUserTest.php
index 0867537..180046f 100644
--- a/tests/Unit/User/UseCases/CreateUserTest.php
+++ b/tests/Unit/User/UseCases/CreateUserTest.php
@@ -2,6 +2,7 @@
 
 namespace Tests\Unit\User\UseCases;
 
+use App\Exceptions\BadRequestException;
 use App\User\User;
 use App\User\UseCases\CreateUser;
 use App\User\UseCases\CreateUserRequest;
@@ -21,4 +22,17 @@ class CreateUserTest extends TestCase
         $this->assertInstanceOf(User::class, $user);
         $this->assertEquals('test@test.com', $user->getEmail());
     }
+
+    public function test_throws_if_email_is_null(): void
+    {
+        $userRepo = new FakeUserRepository();
+        $useCase = new CreateUser($userRepo);
+
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('email is required');
+
+        $useCase->execute(new CreateUserRequest(
+            email: null,
+        ));
+    }
 }
diff --git a/tests/e2e/Controllers/TextControllerTest.php b/tests/e2e/Controllers/TextControllerTest.php
index 3289598..ec5af99 100644
--- a/tests/e2e/Controllers/TextControllerTest.php
+++ b/tests/e2e/Controllers/TextControllerTest.php
@@ -84,4 +84,24 @@ class TextControllerTest extends TestCase
             $response->getBody()
         );
     }
+
+    public function test_create_text_returns_400_when_name_missing(): void
+    {
+        $request = new ServerRequestFactory()
+            ->createServerRequest('POST', 'http://localhost/texts')
+            ->withParsedBody([]);
+
+        $response = $this->controller->createText(
+            $request,
+            new Response(),
+            new CreateText(
+                $this->textRepo,
+                new FakeNodeRepository(),
+            ),
+        );
+
+        $this->assertEquals(400, $response->getStatusCode());
+        $body = json_decode($response->getBody(), true);
+        $this->assertArrayHasKey('error', $body);
+    }
 }