diff --git a/api/components/OAuth2/Component.php b/api/components/OAuth2/Component.php
index d6ad066..f5be5d9 100644
--- a/api/components/OAuth2/Component.php
+++ b/api/components/OAuth2/Component.php
@@ -1,67 +1,40 @@
 <?php
 namespace api\components\OAuth2;
 
-use api\components\OAuth2\Storage\AuthCodeStorage;
-use api\components\OAuth2\Storage\RefreshTokenStorage;
-use api\components\OAuth2\Storage\AccessTokenStorage;
-use api\components\OAuth2\Storage\ClientStorage;
-use api\components\OAuth2\Storage\ScopeStorage;
-use api\components\OAuth2\Storage\SessionStorage;
+use api\components\OAuth2\Storage;
 use api\components\OAuth2\Utils\KeyAlgorithm\UuidAlgorithm;
 use League\OAuth2\Server\AuthorizationServer;
-use League\OAuth2\Server\Grant;
 use League\OAuth2\Server\Util\SecureKey;
-use yii\base\InvalidConfigException;
+use yii\base\Component as BaseComponent;
 
 /**
  * @property AuthorizationServer $authServer
  */
-class Component extends \yii\base\Component {
+class Component extends BaseComponent {
 
     /**
      * @var AuthorizationServer
      */
     private $_authServer;
 
-    /**
-     * @var string[]
-     */
-    public $grantTypes = [];
-
-    /**
-     * @var array grant type => class
-     */
-    public $grantMap = [
-        'authorization_code' => Grant\AuthCodeGrant::class,
-        'client_credentials' => Grant\ClientCredentialsGrant::class,
-        'password'           => Grant\PasswordGrant::class,
-        'refresh_token'      => Grant\RefreshTokenGrant::class,
-    ];
-
-    public function getAuthServer() {
+    public function getAuthServer(): AuthorizationServer {
         if ($this->_authServer === null) {
             $authServer = new AuthorizationServer();
-            $authServer->setAccessTokenStorage(new AccessTokenStorage());
-            $authServer->setClientStorage(new ClientStorage());
-            $authServer->setScopeStorage(new ScopeStorage());
-            $authServer->setSessionStorage(new SessionStorage());
-            $authServer->setAuthCodeStorage(new AuthCodeStorage());
-            $authServer->setRefreshTokenStorage(new RefreshTokenStorage());
+            $authServer->setAccessTokenStorage(new Storage\AccessTokenStorage());
+            $authServer->setClientStorage(new Storage\ClientStorage());
+            $authServer->setScopeStorage(new Storage\ScopeStorage());
+            $authServer->setSessionStorage(new Storage\SessionStorage());
+            $authServer->setAuthCodeStorage(new Storage\AuthCodeStorage());
+            $authServer->setRefreshTokenStorage(new Storage\RefreshTokenStorage());
             $authServer->setScopeDelimiter(',');
             $authServer->setAccessTokenTTL(86400); // 1d
 
+            $authServer->addGrantType(new Grants\AuthCodeGrant());
+            $authServer->addGrantType(new Grants\RefreshTokenGrant());
+            $authServer->addGrantType(new Grants\ClientCredentialsGrant());
+
             $this->_authServer = $authServer;
 
-            foreach ($this->grantTypes as $grantType) {
-                if (!isset($this->grantMap[$grantType])) {
-                    throw new InvalidConfigException('Invalid grant type');
-                }
-
-                /** @var Grant\GrantTypeInterface $grant */
-                $grant = new $this->grantMap[$grantType]();
-                $this->_authServer->addGrantType($grant);
-            }
-
             SecureKey::setAlgorithm(new UuidAlgorithm());
         }
 
diff --git a/api/components/OAuth2/Grants/AuthCodeGrant.php b/api/components/OAuth2/Grants/AuthCodeGrant.php
index 134421a..f8f17e0 100644
--- a/api/components/OAuth2/Grants/AuthCodeGrant.php
+++ b/api/components/OAuth2/Grants/AuthCodeGrant.php
@@ -1,21 +1,221 @@
 <?php
 namespace api\components\OAuth2\Grants;
 
-use api\components\OAuth2\Entities;
-use League\OAuth2\Server\Entity\ClientEntity;
+use api\components\OAuth2\Entities\AccessTokenEntity;
+use api\components\OAuth2\Entities\AuthCodeEntity;
+use api\components\OAuth2\Entities\ClientEntity;
+use api\components\OAuth2\Entities\RefreshTokenEntity;
+use api\components\OAuth2\Entities\SessionEntity;
+use common\models\OauthScope;
+use League\OAuth2\Server\Entity\AuthCodeEntity as BaseAuthCodeEntity;
+use League\OAuth2\Server\Entity\ClientEntity as BaseClientEntity;
+use League\OAuth2\Server\Event\ClientAuthenticationFailedEvent;
+use League\OAuth2\Server\Exception;
+use League\OAuth2\Server\Grant\AbstractGrant;
+use League\OAuth2\Server\Util\SecureKey;
 
-class AuthCodeGrant extends \League\OAuth2\Server\Grant\AuthCodeGrant {
+class AuthCodeGrant extends AbstractGrant {
 
-    protected function createAccessTokenEntity() {
-        return new Entities\AccessTokenEntity($this->server);
+    protected $identifier = 'authorization_code';
+
+    protected $responseType = 'code';
+
+    protected $authTokenTTL = 600;
+
+    protected $requireClientSecret = true;
+
+    public function setAuthTokenTTL(int $authTokenTTL): void {
+        $this->authTokenTTL = $authTokenTTL;
     }
 
-    protected function createRefreshTokenEntity() {
-        return new Entities\RefreshTokenEntity($this->server);
+    public function setRequireClientSecret(bool $required): void {
+        $this->requireClientSecret = $required;
     }
 
-    protected function createSessionEntity() {
-        return new Entities\SessionEntity($this->server);
+    public function shouldRequireClientSecret(): bool {
+        return $this->requireClientSecret;
+    }
+
+    /**
+     * Check authorize parameters
+     *
+     * @return AuthorizeParams Authorize request parameters
+     * @throws Exception\OAuthException
+     *
+     * @throws
+     */
+    public function checkAuthorizeParams(): AuthorizeParams {
+        // Get required params
+        $clientId = $this->server->getRequest()->query->get('client_id');
+        if ($clientId === null) {
+            throw new Exception\InvalidRequestException('client_id');
+        }
+
+        $redirectUri = $this->server->getRequest()->query->get('redirect_uri');
+        if ($redirectUri === null) {
+            throw new Exception\InvalidRequestException('redirect_uri');
+        }
+
+        // Validate client ID and redirect URI
+        $client = $this->server->getClientStorage()->get($clientId, null, $redirectUri, $this->getIdentifier());
+        if (!$client instanceof ClientEntity) {
+            $this->server->getEventEmitter()->emit(new ClientAuthenticationFailedEvent($this->server->getRequest()));
+            throw new Exception\InvalidClientException();
+        }
+
+        $state = $this->server->getRequest()->query->get('state');
+        if ($state === null && $this->server->stateParamRequired()) {
+            throw new Exception\InvalidRequestException('state', $redirectUri);
+        }
+
+        $responseType = $this->server->getRequest()->query->get('response_type');
+        if ($responseType === null) {
+            throw new Exception\InvalidRequestException('response_type', $redirectUri);
+        }
+
+        // Ensure response type is one that is recognised
+        if (!in_array($responseType, $this->server->getResponseTypes(), true)) {
+            throw new Exception\UnsupportedResponseTypeException($responseType, $redirectUri);
+        }
+
+        // Validate any scopes that are in the request
+        $scopeParam = $this->server->getRequest()->query->get('scope', '');
+        $scopes = $this->validateScopes($scopeParam, $client, $redirectUri);
+
+        return new AuthorizeParams($client, $redirectUri, $state, $responseType, $scopes);
+    }
+
+    /**
+     * Parse a new authorize request
+     *
+     * @param string $type       The session owner's type
+     * @param string $typeId     The session owner's ID
+     * @param AuthorizeParams $authParams The authorize request $_GET parameters
+     *
+     * @return string An authorisation code
+     */
+    public function newAuthorizeRequest(string $type, string $typeId, AuthorizeParams $authParams): string {
+        // Create a new session
+        $session = new SessionEntity($this->server);
+        $session->setOwner($type, $typeId);
+        $session->associateClient($authParams->getClient());
+
+        // Create a new auth code
+        $authCode = new AuthCodeEntity($this->server);
+        $authCode->setId(SecureKey::generate());
+        $authCode->setRedirectUri($authParams->getRedirectUri());
+        $authCode->setExpireTime(time() + $this->authTokenTTL);
+
+        foreach ($authParams->getScopes() as $scope) {
+            $authCode->associateScope($scope);
+            $session->associateScope($scope);
+        }
+
+        $session->save();
+        $authCode->setSession($session);
+        $authCode->save();
+
+        return $authCode->generateRedirectUri($authParams->getState());
+    }
+
+    /**
+     * Complete the auth code grant
+     *
+     * @return array
+     *
+     * @throws Exception\OAuthException
+     */
+    public function completeFlow(): array {
+        // Get the required params
+        $clientId = $this->server->getRequest()->request->get('client_id', $this->server->getRequest()->getUser());
+        if ($clientId === null) {
+            throw new Exception\InvalidRequestException('client_id');
+        }
+
+        $clientSecret = $this->server->getRequest()->request->get('client_secret',
+            $this->server->getRequest()->getPassword());
+        if ($clientSecret === null && $this->shouldRequireClientSecret()) {
+            throw new Exception\InvalidRequestException('client_secret');
+        }
+
+        $redirectUri = $this->server->getRequest()->request->get('redirect_uri');
+        if ($redirectUri === null) {
+            throw new Exception\InvalidRequestException('redirect_uri');
+        }
+
+        // Validate client ID and client secret
+        $client = $this->server->getClientStorage()->get($clientId, $clientSecret, $redirectUri, $this->getIdentifier());
+        if (!$client instanceof BaseClientEntity) {
+            $this->server->getEventEmitter()->emit(new ClientAuthenticationFailedEvent($this->server->getRequest()));
+            throw new Exception\InvalidClientException();
+        }
+
+        // Validate the auth code
+        $authCode = $this->server->getRequest()->request->get('code');
+        if ($authCode === null) {
+            throw new Exception\InvalidRequestException('code');
+        }
+
+        $code = $this->server->getAuthCodeStorage()->get($authCode);
+        if (($code instanceof BaseAuthCodeEntity) === false) {
+            throw new Exception\InvalidRequestException('code');
+        }
+
+        // Ensure the auth code hasn't expired
+        if ($code->isExpired()) {
+            throw new Exception\InvalidRequestException('code');
+        }
+
+        // Check redirect URI presented matches redirect URI originally used in authorize request
+        if ($code->getRedirectUri() !== $redirectUri) {
+            throw new Exception\InvalidRequestException('redirect_uri');
+        }
+
+        $session = $code->getSession();
+        $session->associateClient($client);
+
+        $authCodeScopes = $code->getScopes();
+
+        // Generate the access token
+        $accessToken = new AccessTokenEntity($this->server);
+        $accessToken->setId(SecureKey::generate()); // TODO: generate code based on permissions
+        $accessToken->setExpireTime($this->getAccessTokenTTL() + time());
+
+        foreach ($authCodeScopes as $authCodeScope) {
+            $session->associateScope($authCodeScope);
+        }
+
+        foreach ($session->getScopes() as $scope) {
+            $accessToken->associateScope($scope);
+        }
+
+        $this->server->getTokenType()->setSession($session);
+        $this->server->getTokenType()->setParam('access_token', $accessToken->getId());
+        $this->server->getTokenType()->setParam('expires_in', $this->getAccessTokenTTL());
+
+        // Выдаём refresh_token, если запрошен offline_access
+        if (isset($accessToken->getScopes()[OauthScope::OFFLINE_ACCESS])) {
+            /** @var RefreshTokenGrant $refreshTokenGrant */
+            $refreshTokenGrant = $this->server->getGrantType('refresh_token');
+            $refreshToken = new RefreshTokenEntity($this->server);
+            $refreshToken->setId(SecureKey::generate());
+            $refreshToken->setExpireTime($refreshTokenGrant->getRefreshTokenTTL() + time());
+            $this->server->getTokenType()->setParam('refresh_token', $refreshToken->getId());
+        }
+
+        // Expire the auth code
+        $code->expire();
+
+        // Save all the things
+        $accessToken->setSession($session);
+        $accessToken->save();
+
+        if (isset($refreshToken)) {
+            $refreshToken->setAccessToken($accessToken);
+            $refreshToken->save();
+        }
+
+        return $this->server->getTokenType()->generateResponse();
     }
 
     /**
diff --git a/api/components/OAuth2/Grants/AuthorizeParams.php b/api/components/OAuth2/Grants/AuthorizeParams.php
new file mode 100644
index 0000000..c47e90a
--- /dev/null
+++ b/api/components/OAuth2/Grants/AuthorizeParams.php
@@ -0,0 +1,58 @@
+<?php
+namespace api\components\OAuth2\Grants;
+
+use api\components\OAuth2\Entities\ClientEntity;
+
+class AuthorizeParams {
+
+    private $client;
+
+    private $redirectUri;
+
+    private $state;
+
+    private $responseType;
+
+    /**
+     * @var \api\components\OAuth2\Entities\ScopeEntity[]
+     */
+    private $scopes;
+
+    public function __construct(
+        ClientEntity $client,
+        string $redirectUri,
+        ?string $state,
+        string $responseType,
+        array $scopes
+    ) {
+        $this->client = $client;
+        $this->redirectUri = $redirectUri;
+        $this->state = $state;
+        $this->responseType = $responseType;
+        $this->scopes = $scopes;
+    }
+
+    public function getClient(): ClientEntity {
+        return $this->client;
+    }
+
+    public function getRedirectUri(): string {
+        return $this->redirectUri;
+    }
+
+    public function getState(): ?string {
+        return $this->state;
+    }
+
+    public function getResponseType(): string {
+        return $this->responseType;
+    }
+
+    /**
+     * @return \api\components\OAuth2\Entities\ScopeEntity[]
+     */
+    public function getScopes(): array {
+        return $this->scopes ?? [];
+    }
+
+}
diff --git a/api/components/OAuth2/Grants/ClientCredentialsGrant.php b/api/components/OAuth2/Grants/ClientCredentialsGrant.php
index ef80342..e0303bd 100644
--- a/api/components/OAuth2/Grants/ClientCredentialsGrant.php
+++ b/api/components/OAuth2/Grants/ClientCredentialsGrant.php
@@ -1,21 +1,72 @@
 <?php
 namespace api\components\OAuth2\Grants;
 
-use api\components\OAuth2\Entities;
-use League\OAuth2\Server\Entity\ClientEntity;
+use api\components\OAuth2\Entities\AccessTokenEntity;
+use api\components\OAuth2\Entities\SessionEntity;
+use League\OAuth2\Server\Entity\ClientEntity as BaseClientEntity;
+use League\OAuth2\Server\Event;
+use League\OAuth2\Server\Exception;
+use League\OAuth2\Server\Grant\AbstractGrant;
+use League\OAuth2\Server\Util\SecureKey;
 
-class ClientCredentialsGrant extends \League\OAuth2\Server\Grant\ClientCredentialsGrant {
+class ClientCredentialsGrant extends AbstractGrant {
 
-    protected function createAccessTokenEntity() {
-        return new Entities\AccessTokenEntity($this->server);
-    }
+    protected $identifier = 'client_credentials';
 
-    protected function createRefreshTokenEntity() {
-        return new Entities\RefreshTokenEntity($this->server);
-    }
+    /**
+     * @return array
+     * @throws \League\OAuth2\Server\Exception\OAuthException
+     */
+    public function completeFlow(): array {
+        // Get the required params
+        $clientId = $this->server->getRequest()->request->get('client_id', $this->server->getRequest()->getUser());
+        if ($clientId === null) {
+            throw new Exception\InvalidRequestException('client_id');
+        }
 
-    protected function createSessionEntity() {
-        return new Entities\SessionEntity($this->server);
+        $clientSecret = $this->server->getRequest()->request->get('client_secret',
+            $this->server->getRequest()->getPassword());
+        if ($clientSecret === null) {
+            throw new Exception\InvalidRequestException('client_secret');
+        }
+
+        // Validate client ID and client secret
+        $client = $this->server->getClientStorage()->get($clientId, $clientSecret, null, $this->getIdentifier());
+        if (!$client instanceof BaseClientEntity) {
+            $this->server->getEventEmitter()->emit(new Event\ClientAuthenticationFailedEvent($this->server->getRequest()));
+            throw new Exception\InvalidClientException();
+        }
+
+        // Validate any scopes that are in the request
+        $scopeParam = $this->server->getRequest()->request->get('scope', '');
+        $scopes = $this->validateScopes($scopeParam, $client);
+
+        // Create a new session
+        $session = new SessionEntity($this->server);
+        $session->setOwner('client', $client->getId());
+        $session->associateClient($client);
+
+        // Generate an access token
+        $accessToken = new AccessTokenEntity($this->server);
+        $accessToken->setId(SecureKey::generate());
+        $accessToken->setExpireTime($this->getAccessTokenTTL() + time());
+
+        // Associate scopes with the session and access token
+        foreach ($scopes as $scope) {
+            $session->associateScope($scope);
+            $accessToken->associateScope($scope);
+        }
+
+        // Save everything
+        $session->save();
+        $accessToken->setSession($session);
+        $accessToken->save();
+
+        $this->server->getTokenType()->setSession($session);
+        $this->server->getTokenType()->setParam('access_token', $accessToken->getId());
+        $this->server->getTokenType()->setParam('expires_in', $this->getAccessTokenTTL());
+
+        return $this->server->getTokenType()->generateResponse();
     }
 
     /**
diff --git a/api/components/OAuth2/Grants/RefreshTokenGrant.php b/api/components/OAuth2/Grants/RefreshTokenGrant.php
index d6e0161..9062aa7 100644
--- a/api/components/OAuth2/Grants/RefreshTokenGrant.php
+++ b/api/components/OAuth2/Grants/RefreshTokenGrant.php
@@ -1,29 +1,49 @@
 <?php
 namespace api\components\OAuth2\Grants;
 
-use api\components\OAuth2\Entities;
+use api\components\OAuth2\Entities\AccessTokenEntity;
+use api\components\OAuth2\Entities\RefreshTokenEntity;
 use ErrorException;
-use League\OAuth2\Server\Entity\ClientEntity as OriginalClientEntity;
-use League\OAuth2\Server\Entity\ClientEntity;
-use League\OAuth2\Server\Entity\RefreshTokenEntity as OriginalRefreshTokenEntity;
-use League\OAuth2\Server\Event;
+use League\OAuth2\Server\Entity\AccessTokenEntity as BaseAccessTokenEntity;
+use League\OAuth2\Server\Entity\ClientEntity as BaseClientEntity;
+use League\OAuth2\Server\Entity\RefreshTokenEntity as BaseRefreshTokenEntity;
+use League\OAuth2\Server\Event\ClientAuthenticationFailedEvent;
 use League\OAuth2\Server\Exception;
+use League\OAuth2\Server\Grant\AbstractGrant;
 use League\OAuth2\Server\Util\SecureKey;
 
-class RefreshTokenGrant extends \League\OAuth2\Server\Grant\RefreshTokenGrant {
+class RefreshTokenGrant extends AbstractGrant {
 
-    public $refreshTokenRotate = false;
+    protected $identifier = 'refresh_token';
 
-    protected function createAccessTokenEntity() {
-        return new Entities\AccessTokenEntity($this->server);
+    protected $refreshTokenTTL = 604800;
+
+    protected $refreshTokenRotate = false;
+
+    protected $requireClientSecret = true;
+
+    public function setRefreshTokenTTL($refreshTokenTTL): void {
+        $this->refreshTokenTTL = $refreshTokenTTL;
     }
 
-    protected function createRefreshTokenEntity() {
-        return new Entities\RefreshTokenEntity($this->server);
+    public function getRefreshTokenTTL(): int {
+        return $this->refreshTokenTTL;
     }
 
-    protected function createSessionEntity() {
-        return new Entities\SessionEntity($this->server);
+    public function setRefreshTokenRotation(bool $refreshTokenRotate = true): void {
+        $this->refreshTokenRotate = $refreshTokenRotate;
+    }
+
+    public function shouldRotateRefreshTokens(): bool {
+        return $this->refreshTokenRotate;
+    }
+
+    public function setRequireClientSecret(string $required): void {
+        $this->requireClientSecret = $required;
+    }
+
+    public function shouldRequireClientSecret(): bool {
+        return $this->requireClientSecret;
     }
 
     /**
@@ -47,10 +67,11 @@ class RefreshTokenGrant extends \League\OAuth2\Server\Grant\RefreshTokenGrant {
      * Поэтому мы расширили логику RefreshTokenEntity и она теперь знает о сессии, в рамках которой была создана
      *
      * @inheritdoc
+     * @throws \League\OAuth2\Server\Exception\OAuthException
      */
-    public function completeFlow() {
+    public function completeFlow(): array {
         $clientId = $this->server->getRequest()->request->get('client_id', $this->server->getRequest()->getUser());
-        if (is_null($clientId)) {
+        if ($clientId === null) {
             throw new Exception\InvalidRequestException('client_id');
         }
 
@@ -58,31 +79,25 @@ class RefreshTokenGrant extends \League\OAuth2\Server\Grant\RefreshTokenGrant {
             'client_secret',
             $this->server->getRequest()->getPassword()
         );
-        if ($this->shouldRequireClientSecret() && is_null($clientSecret)) {
+        if ($clientSecret === null && $this->shouldRequireClientSecret()) {
             throw new Exception\InvalidRequestException('client_secret');
         }
 
         // Validate client ID and client secret
-        $client = $this->server->getClientStorage()->get(
-            $clientId,
-            $clientSecret,
-            null,
-            $this->getIdentifier()
-        );
-
-        if (($client instanceof OriginalClientEntity) === false) {
-            $this->server->getEventEmitter()->emit(new Event\ClientAuthenticationFailedEvent($this->server->getRequest()));
+        $client = $this->server->getClientStorage()->get($clientId, $clientSecret, null, $this->getIdentifier());
+        if (($client instanceof BaseClientEntity) === false) {
+            $this->server->getEventEmitter()->emit(new ClientAuthenticationFailedEvent($this->server->getRequest()));
             throw new Exception\InvalidClientException();
         }
 
-        $oldRefreshTokenParam = $this->server->getRequest()->request->get('refresh_token', null);
+        $oldRefreshTokenParam = $this->server->getRequest()->request->get('refresh_token');
         if ($oldRefreshTokenParam === null) {
             throw new Exception\InvalidRequestException('refresh_token');
         }
 
         // Validate refresh token
         $oldRefreshToken = $this->server->getRefreshTokenStorage()->get($oldRefreshTokenParam);
-        if (($oldRefreshToken instanceof OriginalRefreshTokenEntity) === false) {
+        if (($oldRefreshToken instanceof BaseRefreshTokenEntity) === false) {
             throw new Exception\InvalidRefreshException();
         }
 
@@ -91,14 +106,15 @@ class RefreshTokenGrant extends \League\OAuth2\Server\Grant\RefreshTokenGrant {
             throw new Exception\InvalidRefreshException();
         }
 
-        /** @var Entities\AccessTokenEntity|null $oldAccessToken */
+        /** @var AccessTokenEntity|null $oldAccessToken */
         $oldAccessToken = $oldRefreshToken->getAccessToken();
-        if ($oldAccessToken instanceof Entities\AccessTokenEntity) {
+        if ($oldAccessToken instanceof AccessTokenEntity) {
             // Get the scopes for the original session
             $session = $oldAccessToken->getSession();
         } else {
-            if (!$oldRefreshToken instanceof Entities\RefreshTokenEntity) {
-                throw new ErrorException('oldRefreshToken must be instance of ' . Entities\RefreshTokenEntity::class);
+            if (!$oldRefreshToken instanceof RefreshTokenEntity) {
+                /** @noinspection ExceptionsAnnotatingAndHandlingInspection */
+                throw new ErrorException('oldRefreshToken must be instance of ' . RefreshTokenEntity::class);
             }
 
             $session = $oldRefreshToken->getSession();
@@ -126,8 +142,8 @@ class RefreshTokenGrant extends \League\OAuth2\Server\Grant\RefreshTokenGrant {
         }
 
         // Generate a new access token and assign it the correct sessions
-        $newAccessToken = $this->createAccessTokenEntity();
-        $newAccessToken->setId(SecureKey::generate());
+        $newAccessToken = new AccessTokenEntity($this->server);
+        $newAccessToken->setId(SecureKey::generate()); // TODO: generate based on permissions
         $newAccessToken->setExpireTime($this->getAccessTokenTTL() + time());
         $newAccessToken->setSession($session);
 
@@ -136,7 +152,7 @@ class RefreshTokenGrant extends \League\OAuth2\Server\Grant\RefreshTokenGrant {
         }
 
         // Expire the old token and save the new one
-        ($oldAccessToken instanceof Entities\AccessTokenEntity) && $oldAccessToken->expire();
+        $oldAccessToken instanceof BaseAccessTokenEntity && $oldAccessToken->expire();
         $newAccessToken->save();
 
         $this->server->getTokenType()->setSession($session);
@@ -148,7 +164,7 @@ class RefreshTokenGrant extends \League\OAuth2\Server\Grant\RefreshTokenGrant {
             $oldRefreshToken->expire();
 
             // Generate a new refresh token
-            $newRefreshToken = $this->createRefreshTokenEntity();
+            $newRefreshToken = new RefreshTokenEntity($this->server);
             $newRefreshToken->setId(SecureKey::generate());
             $newRefreshToken->setExpireTime($this->getRefreshTokenTTL() + time());
             $newRefreshToken->setAccessToken($newAccessToken);
diff --git a/api/models/OauthProcess.php b/api/models/OauthProcess.php
index bf598a4..02a5ddb 100644
--- a/api/models/OauthProcess.php
+++ b/api/models/OauthProcess.php
@@ -3,13 +3,13 @@ namespace api\models;
 
 use api\components\OAuth2\Exception\AcceptRequiredException;
 use api\components\OAuth2\Exception\AccessDeniedException;
+use api\components\OAuth2\Grants\AuthCodeGrant;
+use api\components\OAuth2\Grants\AuthorizeParams;
 use common\models\Account;
 use common\models\OauthClient;
-use common\models\OauthScope;
 use League\OAuth2\Server\AuthorizationServer;
 use League\OAuth2\Server\Exception\InvalidGrantException;
 use League\OAuth2\Server\Exception\OAuthException;
-use League\OAuth2\Server\Grant\AuthCodeGrant;
 use League\OAuth2\Server\Grant\GrantTypeInterface;
 use Yii;
 use yii\helpers\ArrayHelper;
@@ -45,14 +45,13 @@ class OauthProcess {
     public function validate(): array {
         try {
             $authParams = $this->getAuthorizationCodeGrant()->checkAuthorizeParams();
-            /** @var \League\OAuth2\Server\Entity\ClientEntity $client */
-            $client = $authParams['client'];
+            $client = $authParams->getClient();
             /** @var \common\models\OauthClient $clientModel */
             $clientModel = OauthClient::findOne($client->getId());
             $response = $this->buildSuccessResponse(
                 Yii::$app->request->getQueryParams(),
                 $clientModel,
-                $authParams['scopes']
+                $authParams->getScopes()
             );
         } catch (OAuthException $e) {
             $response = $this->buildErrorResponse($e);
@@ -85,10 +84,8 @@ class OauthProcess {
             $grant = $this->getAuthorizationCodeGrant();
             $authParams = $grant->checkAuthorizeParams();
             $account = Yii::$app->user->identity;
-            /** @var \League\OAuth2\Server\Entity\ClientEntity $client */
-            $client = $authParams['client'];
             /** @var \common\models\OauthClient $clientModel */
-            $clientModel = OauthClient::findOne($client->getId());
+            $clientModel = OauthClient::findOne($authParams->getClient()->getId());
 
             if (!$this->canAutoApprove($account, $clientModel, $authParams)) {
                 $isAccept = Yii::$app->request->post('accept');
@@ -97,7 +94,7 @@ class OauthProcess {
                 }
 
                 if (!$isAccept) {
-                    throw new AccessDeniedException($authParams['redirect_uri']);
+                    throw new AccessDeniedException($authParams->getRedirectUri());
                 }
             }
 
@@ -135,7 +132,6 @@ class OauthProcess {
      * @return array
      */
     public function getToken(): array {
-        $this->attachRefreshTokenGrantIfNeeded();
         try {
             $response = $this->server->issueAccessToken();
         } catch (OAuthException $e) {
@@ -149,66 +145,26 @@ class OauthProcess {
         return $response;
     }
 
-    /**
-     * Этот метод нужен за тем, что \League\OAuth2\Server\AuthorizationServer не предоставляет
-     * метода для проверки, можно ли выдавать refresh_token для пришедшего токена. Он просто
-     * выдаёт refresh_token, если этот grant присутствует в конфигурации сервера. Так что чтобы
-     * как-то решить эту проблему, мы не включаем RefreshTokenGrant в базовую конфигурацию сервера,
-     * а подключаем его только в том случае, если у auth_token есть право на рефреш или если это
-     * и есть запрос на refresh токена.
-     */
-    private function attachRefreshTokenGrantIfNeeded(): void {
-        if ($this->server->hasGrantType('refresh_token')) {
-            return;
-        }
-
-        $grantType = Yii::$app->request->post('grant_type');
-        if ($grantType === 'authorization_code' && Yii::$app->request->post('code')) {
-            $authCode = Yii::$app->request->post('code');
-            $codeModel = $this->server->getAuthCodeStorage()->get($authCode);
-            if ($codeModel === null) {
-                return;
-            }
-
-            $scopes = $codeModel->getScopes();
-            if (!array_key_exists(OauthScope::OFFLINE_ACCESS, $scopes)) {
-                return;
-            }
-        } elseif ($grantType === 'refresh_token') {
-            // Это валидный кейс
-        } else {
-            return;
-        }
-
-        $grantClass = Yii::$app->oauth->grantMap['refresh_token'];
-        /** @var \League\OAuth2\Server\Grant\RefreshTokenGrant $grant */
-        $grant = new $grantClass;
-
-        $this->server->addGrantType($grant);
-    }
-
     /**
      * Метод проверяет, может ли текущий пользователь быть автоматически авторизован
      * для указанного клиента без запроса доступа к необходимому списку прав
      *
-     * @param Account     $account
+     * @param Account $account
      * @param OauthClient $client
-     * @param array       $oauthParams
+     * @param AuthorizeParams $oauthParams
      *
      * @return bool
      */
-    private function canAutoApprove(Account $account, OauthClient $client, array $oauthParams): bool {
+    private function canAutoApprove(Account $account, OauthClient $client, AuthorizeParams $oauthParams): bool {
         if ($client->is_trusted) {
             return true;
         }
 
-        /** @var \League\OAuth2\Server\Entity\ScopeEntity[] $scopes */
-        $scopes = $oauthParams['scopes'];
         /** @var \common\models\OauthSession|null $session */
         $session = $account->getOauthSessions()->andWhere(['client_id' => $client->id])->one();
         if ($session !== null) {
             $existScopes = $session->getScopes()->members();
-            if (empty(array_diff(array_keys($scopes), $existScopes))) {
+            if (empty(array_diff(array_keys($oauthParams->getScopes()), $existScopes))) {
                 return true;
             }
         }
@@ -216,11 +172,18 @@ class OauthProcess {
         return false;
     }
 
-    private function buildSuccessResponse(array $params, OauthClient $client, array $scopes): array {
+    /**
+     * @param array $queryParams
+     * @param OauthClient $client
+     * @param \api\components\OAuth2\Entities\ScopeEntity[] $scopes
+     *
+     * @return array
+     */
+    private function buildSuccessResponse(array $queryParams, OauthClient $client, array $scopes): array {
         return [
             'success' => true,
             // Возвращаем только те ключи, которые имеют реальное отношение к oAuth параметрам
-            'oAuth' => array_intersect_key($params, array_flip([
+            'oAuth' => array_intersect_key($queryParams, array_flip([
                 'client_id',
                 'redirect_uri',
                 'response_type',
@@ -230,7 +193,7 @@ class OauthProcess {
             'client' => [
                 'id' => $client->id,
                 'name' => $client->name,
-                'description' => ArrayHelper::getValue($params, 'description', $client->description),
+                'description' => ArrayHelper::getValue($queryParams, 'description', $client->description),
             ],
             'session' => [
                 'scopes' => array_keys($scopes),
diff --git a/common/config/config.php b/common/config/config.php
index 19168d0..6b35122 100644
--- a/common/config/config.php
+++ b/common/config/config.php
@@ -71,12 +71,6 @@ return [
         ],
         'oauth' => [
             'class' => api\components\OAuth2\Component::class,
-            'grantTypes' => ['authorization_code', 'client_credentials'],
-            'grantMap' => [
-                'authorization_code' => api\components\OAuth2\Grants\AuthCodeGrant::class,
-                'refresh_token' => api\components\OAuth2\Grants\RefreshTokenGrant::class,
-                'client_credentials' => api\components\OAuth2\Grants\ClientCredentialsGrant::class,
-            ],
         ],
     ],
     'container' => [
diff --git a/composer.json b/composer.json
index 6dc66a0..7ab0e6c 100644
--- a/composer.json
+++ b/composer.json
@@ -9,7 +9,7 @@
         "yiisoft/yii2": "2.0.12",
         "yiisoft/yii2-swiftmailer": "*",
         "ramsey/uuid": "^3.5.0",
-        "league/oauth2-server": "dev-improvements#fbaa9b0bd3d8050235ba7dde90f731764122bc20",
+        "league/oauth2-server": "^4.1",
         "yiisoft/yii2-redis": "~2.0.0",
         "guzzlehttp/guzzle": "^6.0.0",
         "php-amqplib/php-amqplib": "^2.6.2",
@@ -51,10 +51,6 @@
             "type": "git",
             "url": "git@gitlab.ely.by:elyby/email-renderer.git"
         },
-        {
-            "type": "git",
-            "url": "git@gitlab.ely.by:elyby/oauth2-server.git"
-        },
         {
             "type": "git",
             "url": "git@github.com:erickskrauch/php-mock-mockery.git"