diff --git a/src/Api/V1/Controller/AbstractApiController.php b/src/Api/V1/Controller/AbstractApiController.php
index fb0a90c..47f5548 100644
--- a/src/Api/V1/Controller/AbstractApiController.php
+++ b/src/Api/V1/Controller/AbstractApiController.php
@@ -8,7 +8,7 @@ use Symfony\Component\HttpFoundation\{JsonResponse, Response};
 
 abstract class AbstractApiController extends Controller
 {
-    protected const DEFAULT_SERIALIZER_GROUPS = ['api_v1'];
+    protected const DEFAULT_SERIALIZER_GROUPS = ['api'];
 
     protected function createJsonResponse($data, array $groups = [], int $code = Response::HTTP_OK, string $message = null, string $status = ''): JsonResponse
     {
diff --git a/src/Api/V1/Controller/SecurityController.php b/src/Api/V1/Controller/SecurityController.php
index 46c3a6f..7f123db 100644
--- a/src/Api/V1/Controller/SecurityController.php
+++ b/src/Api/V1/Controller/SecurityController.php
@@ -2,12 +2,42 @@
 
 namespace App\Api\V1\Controller;
 
+use App\Entity\{ApiToken, User};
+use App\Repository\{ApiTokenRepository, UserRepository};
+use Doctrine\ORM\EntityManagerInterface;
 use Symfony\Component\HttpFoundation\{JsonResponse, Request};
+use Symfony\Component\Security\Core\Encoder\UserPasswordEncoderInterface;
 
 class SecurityController extends AbstractApiController
 {
-    public function login(Request $request): JsonResponse
-    {
-        // @todo implement login procedure
+    public function login(
+        Request $request,
+        EntityManagerInterface $em,
+        UserRepository $userRepo,
+        ApiTokenRepository $tokenRepo,
+        UserPasswordEncoderInterface $passwordEncoder
+    ): JsonResponse {
+        $username = $request->request->get('username');
+        $password = $request->request->get('password');
+
+        /** @var User $user */
+        if (null === $user = $userRepo->findOneBy(['username' => $username])) {
+            return $this->createJsonResponse(null, [], JsonResponse::HTTP_UNAUTHORIZED, 'User not found');
+        }
+
+        if (!$passwordEncoder->isPasswordValid($user, $password)) {
+            return $this->createJsonResponse(null, [], JsonResponse::HTTP_UNAUTHORIZED, 'Invalid password');
+        }
+
+        $apiToken = new ApiToken($user);
+        $tokenRepo->add($apiToken);
+
+        try {
+            $em->flush();
+        } catch (\Exception $ex) {
+            return $this->createJsonResponse(null, [], JsonResponse::HTTP_INTERNAL_SERVER_ERROR, 'Token persisting error');
+        }
+
+        return $this->createJsonResponse($apiToken->getKey());
     }
 }
\ No newline at end of file
diff --git a/src/Api/V1/DTO/ApiResponse.php b/src/Api/V1/DTO/ApiResponse.php
index b31a6ed..92dcd7f 100644
--- a/src/Api/V1/DTO/ApiResponse.php
+++ b/src/Api/V1/DTO/ApiResponse.php
@@ -15,28 +15,28 @@ class ApiResponse
     /**
      * @var int HTTP response status code
      *
-     * @Groups({"api_v1"})
+     * @Groups({"api"})
      */
     private $code;
 
     /**
      * @var string Status text: 'success' (1xx-3xx), 'error' (4xx), 'fail' (5xx) or 'unknown'
      *
-     * @Groups({"api_v1"})
+     * @Groups({"api"})
      */
     private $status;
 
     /**
      * @var string|null Used for 'fail' and 'error'
      *
-     * @Groups({"api_v1"})
+     * @Groups({"api"})
      */
     private $message;
 
     /**
      * @var string|\object|array|null Response body. In case of 'error' or 'fail' contains cause or exception name.
      *
-     * @Groups({"api_v1"})
+     * @Groups({"api"})
      */
     private $data;
 
diff --git a/src/Api/V1/DTO/ListPage.php b/src/Api/V1/DTO/ListPage.php
index 6c81cfd..3ddd47b 100644
--- a/src/Api/V1/DTO/ListPage.php
+++ b/src/Api/V1/DTO/ListPage.php
@@ -10,35 +10,35 @@ class ListPage
     /**
      * @var int
      *
-     * @Serializer\Groups({"api_v1"})
+     * @Serializer\Groups({"api"})
      */
     private $numberOfPages;
 
     /**
      * @var int
      *
-     * @Serializer\Groups({"api_v1"})
+     * @Serializer\Groups({"api"})
      */
     private $currentPage;
 
     /**
      * @var int
      *
-     * @Serializer\Groups({"api_v1"})
+     * @Serializer\Groups({"api"})
      */
     private $numberOfResults;
 
     /**
      * @var int
      *
-     * @Serializer\Groups({"api_v1"})
+     * @Serializer\Groups({"api"})
      */
     private $maxPerPage;
 
     /**
      * @var \Traversable
      *
-     * @Serializer\Groups({"api_v1"})
+     * @Serializer\Groups({"api"})
      */
     protected $items;
 
diff --git a/src/Entity/ApiToken.php b/src/Entity/ApiToken.php
index 61ef9d1..eb58869 100644
--- a/src/Entity/ApiToken.php
+++ b/src/Entity/ApiToken.php
@@ -3,6 +3,7 @@
 namespace App\Entity;
 
 use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Serializer\Annotation as Serializer;
 
 /**
  * @ORM\Table(name="api_tokens", schema="users")
@@ -21,6 +22,8 @@ class ApiToken
     /**
      * @var string
      *
+     * @Serializer\Groups({"api", "api_v1_login"})
+     *
      * @ORM\Id()
      * @ORM\Column(name="key", type="string", length=32)
      */
diff --git a/src/Repository/ApiTokenRepository.php b/src/Repository/ApiTokenRepository.php
index 0a7847b..523be7c 100644
--- a/src/Repository/ApiTokenRepository.php
+++ b/src/Repository/ApiTokenRepository.php
@@ -4,6 +4,7 @@ namespace App\Repository;
 
 use App\Entity\{ApiToken, User};
 use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\ORM\Query\Expr\Join;
 use Symfony\Bridge\Doctrine\RegistryInterface;
 
 class ApiTokenRepository extends ServiceEntityRepository
@@ -20,9 +21,11 @@ class ApiTokenRepository extends ServiceEntityRepository
 
     public function findUserByTokenKey(string $tokenKey): ?User
     {
-        $qb = $this->createQueryBuilder('at');
+        $qb = $this->getEntityManager()->createQueryBuilder();
         $qb
-            ->select('at.user')
+            ->select('u')
+            ->from(User::class, 'u')
+            ->innerJoin(ApiToken::class, 'at', Join::WITH, 'at.user = u')
             ->where('at.key = :tokenKey')
             ->setParameter('tokenKey', $tokenKey)
         ;