diff --git a/src/DataObject.php b/src/DataObject.php
index d703f47..ebfb754 100644
--- a/src/DataObject.php
+++ b/src/DataObject.php
@@ -9,7 +9,7 @@ use Illuminate\Http\Request;
 
 trait DataObject
 {
-    public static function fromRequest(Request $request): mixed
+    public static function fromRequest(Request $request): ?static
     {
         return DataObjectFactory::fromRequest(static::class, $request);
     }
diff --git a/src/Factories/DataObjectFactory.php b/src/Factories/DataObjectFactory.php
index 9ba6f88..89ae40c 100644
--- a/src/Factories/DataObjectFactory.php
+++ b/src/Factories/DataObjectFactory.php
@@ -118,14 +118,18 @@ class DataObjectFactory
             }
 
             if ($reflectionType instanceof ReflectionNamedType) {
-                $input[$parameterName] = $reflectionType->isBuiltin()
-                    ? $rawInput[$parameterName]
-                    : self::mapInput($reflectionType->__toString(), $rawInput[$parameterName], $routeParameters, $logger);
-
+                if ($reflectionType->isBuiltin()) {
+                    if (array_key_exists($parameterName, $rawInput)) {
+                        $input[$parameterName] = $rawInput[$parameterName];
+                    }
+                } else {
+                    $input[$parameterName] = self::mapInput($reflectionType->__toString(), $rawInput[$parameterName], $routeParameters, $logger);
+                }
                 continue;
             }
-
-            $input[$parameterName] = $rawInput[$parameterName];
+            if (array_key_exists($parameterName, $rawInput)) {
+                $input[$parameterName] = $rawInput[$parameterName];
+            }
         }
         $logger->debug('input', $input);
         return $input;
diff --git a/src/Factories/ValueFactory.php b/src/Factories/ValueFactory.php
index 3f262cd..5509c51 100644
--- a/src/Factories/ValueFactory.php
+++ b/src/Factories/ValueFactory.php
@@ -137,6 +137,6 @@ class ValueFactory
 
             $arguments[$name] = $parameterArgs;
         }
-        return App::makeWith($class, $arguments);
+        return new $class(...$arguments);
     }
 }
diff --git a/src/IDataObject.php b/src/IDataObject.php
new file mode 100644
index 0000000..5797c95
--- /dev/null
+++ b/src/IDataObject.php
@@ -0,0 +1,6 @@
+<?php
+
+namespace Icefox\DTO;
+
+interface IDataObject {}
+
diff --git a/src/Providers/DataObjectServiceProvider.php b/src/Providers/DataObjectServiceProvider.php
new file mode 100644
index 0000000..a90acc7
--- /dev/null
+++ b/src/Providers/DataObjectServiceProvider.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Icefox\DTO\Providers;
+
+use Icefox\DTO\Factories\DataObjectFactory;
+use Icefox\DTO\IDataObject;
+use Illuminate\Support\ServiceProvider;
+
+class DataObjectServiceProvider extends ServiceProvider
+{
+    public function register(): void
+    {
+        $this->app->beforeResolving(function ($abstract, $parameters, $app) {
+            if ($app->has($abstract)) {
+                return;
+            }
+            if (is_subclass_of($abstract, IDataObject::class)) {
+                $app->bind($abstract, fn($container) => DataObjectFactory::fromRequest($abstract, $container['request']));
+            }
+        });
+    }
+}
+
diff --git a/tests/DataObject/DataObjectTest.php b/tests/DataObject/DataObjectTest.php
index 5994877..30b3055 100644
--- a/tests/DataObject/DataObjectTest.php
+++ b/tests/DataObject/DataObjectTest.php
@@ -3,6 +3,7 @@
 namespace Tests\DataObject;
 
 use Icefox\DTO\Attributes\FromInput;
+use Icefox\DTO\Attributes\FromRouteParameter;
 use Icefox\DTO\Factories\DataObjectFactory;
 use Illuminate\Support\Collection;
 use Psr\Log\NullLogger;
@@ -125,3 +126,70 @@ test('annotated array', function () {
 
     expect($mapped)->toBe(['items' => [['value' => 1], ['value' => 2]]]);
 });
+
+test('route parameter priority over from input', function () {
+    $dto = new class (123) {
+        public function __construct(
+            #[FromRouteParameter('user_id')]
+            #[FromInput('user_id')]
+            public int $id,
+        ) {}
+    };
+
+    $result = DataObjectFactory::mapInput(
+        $dto::class,
+        ['user_id' => 456],
+        ['user_id' => 123],
+        new \Psr\Log\NullLogger(),
+    );
+
+    expect($result['id'])->toBe(123);
+});
+
+test('multiple route parameters', function () {
+    $dto = new class (45, 89, 'A') {
+        public function __construct(
+            #[FromRouteParameter('course_id')]
+            public int $courseId,
+            #[FromRouteParameter('student_id')]
+            public int $studentId,
+            #[FromInput('grade')]
+            public string $grade,
+        ) {}
+    };
+
+    $result = DataObjectFactory::mapInput(
+        $dto::class,
+        ['grade' => 'A'],
+        ['course_id' => 45, 'student_id' => 89],
+        new \Psr\Log\NullLogger(),
+    );
+
+    expect($result['courseId'])->toBe(45)
+        ->and($result['studentId'])->toBe(89)
+        ->and($result['grade'])->toBe('A');
+});
+
+test('route parameter with nested object', function () {
+    $addressDto = new class ('Main St') {
+        public function __construct(public string $street) {}
+    };
+
+    $dto = new class (123, $addressDto) {
+        public function __construct(
+            #[FromRouteParameter('user_id')]
+            public int $userId,
+            public $address,
+        ) {}
+    };
+
+    $result = DataObjectFactory::mapInput(
+        $dto::class,
+        ['user_id' => 456, 'address' => ['street' => 'Main St']],
+        ['user_id' => 123],
+        new \Psr\Log\NullLogger(),
+    );
+
+    expect($result['userId'])->toBe(123)
+        ->and($result['address']['street'])->toBe('Main St');
+});
diff --git a/tests/Http/RequestTest.php b/tests/Http/RequestTest.php
new file mode 100644
index 0000000..c92e06d
--- /dev/null
+++ b/tests/Http/RequestTest.php
@@ -0,0 +1,107 @@
+<?php
+
+namespace Tests\Http;
+
+use Icefox\DTO\IDataObject;
+use Illuminate\Http\Exceptions\HttpResponseException;
+use Illuminate\Support\Facades\Route;
+use Illuminate\Support\Facades\Validator as ValidatorFacade;
+use Illuminate\Validation\Validator;
+
+readonly class Basic implements IDataObject
+{
+    public string $reply;
+    public function __construct(string $message)
+    {
+        $this->reply = $message == 'ping' ? 'pong' : 'unknown';
+    }
+}
+
+test('injects data object', function () {
+    Route::post('/', fn(Basic $object) => ['reply' => $object->reply]);
+
+    /** @var \Tests\TestCase $this */
+    $this->postJson('/', ['message' => 'ping'])->assertJson(['reply' => 'pong']);
+});
+
+test('fails on validation error', function () {
+    Route::post('/', fn(Basic $object) => ['reply' => $object->reply]);
+    /** @var \Tests\TestCase $this */
+    $resp = $this->postJson('/', [])
+        ->assertStatus(422)
+        ->assertJson([
+            'message' =>  'The message field is required.',
+            'errors' => ['message' => ['The message field is required.']],
+        ]);
+});
+
+readonly class WithCustomValidator implements IDataObject
+{
+    public string $reply;
+    public function __construct(string $message)
+    {
+        $this->reply = $message == 'ping' ? 'pong' : 'unknown';
+    }
+
+    /**
+     * @param array<string,mixed> $data
+     * @param array<string,mixed> $rules
+     */
+    public static function withValidator(array $data, array $rules): Validator
+    {
+        return ValidatorFacade::make($data, $rules, $messages = [
+            'message.required' => 'the known message is pong',
+        ]);
+    }
+}
+
+test('replies with custom validator', function () {
+    Route::post('/', fn(WithCustomValidator $object) => []);
+    /** @var \Tests\TestCase $this */
+    $this->postJson('/', [])
+        ->assertStatus(422)
+        ->assertJson([
+            'message' =>  'the known message is pong',
+            'errors' => ['message' => ['the known message is pong']],
+        ]);
+});
+
+readonly class WithCustomFailure implements IDataObject
+{
+    public function __construct(public bool $flag) {}
+
+    public static function fails(Validator $validator): void
+    {
+        throw new HttpResponseException(
+            response(['result' => 'invalid, but that is ok' ], 202),
+        );
+    }
+}
+
+test('uses custom response', function () {
+    Route::post('/', fn(WithCustomFailure $object) => response('', 204));
+
+    /** @var \Tests\TestCase $this */
+    $this->postJson('/', [])
+        ->assertStatus(202)
+        ->assertJson(['result' => 'invalid, but that is ok']);
+});
+
+readonly class WithDefaultObjectOnFailure implements IDataObject
+{
+    public function __construct(public bool $flag) {}
+
+    public static function fails(): self
+    {
+        return new self(false);
+    }
+}
+
+test('uses default object on failure', function () {
+    Route::post('/', fn(WithDefaultObjectOnFailure $object) => response(['flag' => $object->flag], 200));
+
+    /** @var \Tests\TestCase $this */
+    $this->postJson('/', [])
+        ->assertStatus(200)
+        ->assertJson(['flag' => false]);
+});
diff --git a/tests/Http/RequestTests.php b/tests/Http/RequestTests.php
deleted file mode 100644
index b253e7d..0000000
--- a/tests/Http/RequestTests.php
+++ /dev/null
@@ -1,206 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Tests\Http;
-
-use Icefox\DTO\Attributes\FromInput;
-use Icefox\DTO\Attributes\FromRouteParameter;
-use Icefox\DTO\Factories\DataObjectFactory;
-use Icefox\DTO\Factories\ValueFactory;
-use Illuminate\Routing\Route;
-use Illuminate\Validation\ValidationException;
-use Illuminate\Validation\Validator;
-
-readonly class SimplePostDTO
-{
-    public function __construct(
-        public string $title,
-        public string $content,
-    ) {}
-}
-
-test('successful validation returns 200 equivalent', function () {
-    $dto = DataObjectFactory::fromArray(SimplePostDTO::class, [
-        'title' => 'Test Title',
-        'content' => 'Test Content',
-    ], []);
-
-    expect($dto)->toBeInstanceOf(SimplePostDTO::class)
-        ->and($dto->title)->toBe('Test Title')
-        ->and($dto->content)->toBe('Test Content');
-});
-
-test('failed validation throws validation exception', function () {
-    try {
-        DataObjectFactory::fromArray(SimplePostDTO::class, [
-            'title' => 'Test',
-            'content' => [],
-        ], []);
-    } catch (\Throwable $e) {
-        expect($e)->toBeInstanceOf(ValidationException::class);
-        return;
-    }
-    throw new \Exception('Should have thrown an exception');
-});
-
-readonly class PostDTOWithNumeric
-{
-    public function __construct(
-        public string $title,
-        public int $views,
-    ) {}
-}
-
-test('failed validation returns proper error format', function () {
-    try {
-        DataObjectFactory::fromArray(PostDTOWithNumeric::class, [
-            'title' => 'Test',
-            'views' => 'not-a-number',
-        ], []);
-    } catch (ValidationException $e) {
-        $errors = $e->validator->errors();
-
-        expect($errors->has('views'))->toBeTrue()
-            ->and($errors->first('views'))->toContain('number');
-    }
-});
-
-test('validation error message format matches laravel', function () {
-    try {
-        DataObjectFactory::fromArray(PostDTOWithNumeric::class, [
-            'title' => 'Test',
-            'views' => 'invalid',
-        ], []);
-    } catch (ValidationException $e) {
-        $errors = $e->validator->errors()->toArray();
-
-        expect($errors)->toHaveKey('views')
-            ->and($errors['views'][0])->toContain('views');
-    }
-});
-
-readonly class RestrictedDTO
-{
-    public function __construct(public string $content) {}
-
-    public static function fails($validator): object
-    {
-        return (object) [
-            'error' => 'Access denied',
-            'details' => $validator->errors()->toArray(),
-            'status' => 403,
-        ];
-    }
-}
-
-test('custom fails returns custom response structure', function () {
-    $result = DataObjectFactory::fromArray(RestrictedDTO::class, [
-        'content' => [],  // invalid - must be string
-    ], []);
-
-    expect($result->error)->toBe('Access denied')
-        ->and($result->details)->toHaveKey('content')
-        ->and($result->status)->toBe(403);
-});
-
-readonly class CustomBagDTO
-{
-    public string $name;
-    public float $price;
-
-    public function __construct(string $name, float $price)
-    {
-        $this->name = $name;
-        $this->price = $price;
-    }
-
-    public static function rules(): array
-    {
-        return [
-            'name' => ['required', 'min:3'],
-            'price' => ['required', 'numeric', 'min:0'],
-        ];
-    }
-}
-
-test('named error bag test', function () {
-    try {
-        DataObjectFactory::fromArray(CustomBagDTO::class, [
-            'name' => 'ab',
-            'price' => -10,
-        ], []);
-    } catch (ValidationException $e) {
-        $errors = $e->validator->errors()->toArray();
-
-        expect($errors)->toHaveKey('name')
-            ->and($errors)->toHaveKey('price');
-    }
-});
-
-test('route parameter priority over from input', function () {
-    $dto = new class (123) {
-        public function __construct(
-            #[FromRouteParameter('user_id')]
-            #[FromInput('user_id')]
-            public int $id,
-        ) {}
-    };
-
-    $result = DataObjectFactory::mapInput(
-        $dto::class,
-        ['user_id' => 456],
-        ['user_id' => 123],
-        new \Psr\Log\NullLogger(),
-    );
-
-    expect($result['id'])->toBe(123);
-});
-
-test('multiple route parameters', function () {
-    $dto = new class (45, 89, 'A') {
-        public function __construct(
-            #[FromRouteParameter('course_id')]
-            public int $courseId,
-            #[FromRouteParameter('student_id')]
-            public int $studentId,
-            #[FromInput('grade')]
-            public string $grade,
-        ) {}
-    };
-
-    $result = DataObjectFactory::mapInput(
-        $dto::class,
-        ['grade' => 'A'],
-        ['course_id' => 45, 'student_id' => 89],
-        new \Psr\Log\NullLogger(),
-    );
-
-    expect($result['courseId'])->toBe(45)
-        ->and($result['studentId'])->toBe(89)
-        ->and($result['grade'])->toBe('A');
-});
-
-test('route parameter with nested object', function () {
-    $addressDto = new class ('Main St') {
-        public function __construct(public string $street) {}
-    };
-
-    $dto = new class (123, $addressDto) {
-        public function __construct(
-            #[FromRouteParameter('user_id')]
-            public int $userId,
-            public $address,
-        ) {}
-    };
-
-    $result = DataObjectFactory::mapInput(
-        $dto::class,
-        ['user_id' => 456, 'address' => ['street' => 'Main St']],
-        ['user_id' => 123],
-        new \Psr\Log\NullLogger(),
-    );
-
-    expect($result['userId'])->toBe(123)
-        ->and($result['address']['street'])->toBe('Main St');
-});