diff --git a/CHANGELOG b/CHANGELOG
deleted file mode 100644
index 2c93c39..0000000
--- a/CHANGELOG
+++ /dev/null
@@ -1,56 +0,0 @@
-4.0.0-beta
-      - Simplify code
-      - DI ready
-      - Improve PSRs support
-
-3.1.2 - Businesses service added
-      - SmartCampaigns support added
-      - SmartBanners support added
-      - checkDictionaries fix
-
-3.1.1 - Fix scrutinizer reflection issue
-
-3.1.0 - Improve params mapping
-      - NegativeKeywordSharedSets service added
-      - Creatives service added
-      - KeywordsResearch::deduplicate method added
-      - Clients::update method added
-
-3.0.1 - AgencyClients add and update methods
-      - Codestyle fixes
-
-3.0.0 - New parameters to Ads and Campaign services
-
-2.5.0 - Add TurboPages service mapping
-
-2.4.0 - Fix bc for report service
-
-2.3.1 - Fix report service
-      - Fix report call example
-
-2.3.0 - Report goals support added
- 
-2.2.3 - KeywordBids setAuto method
-      - Update phpdoc codestyle
-
-2.2.2 - Remove lockfile
-
-2.2.1 - KeywordBids added
-      - Leads added
-      - Codestyle fixes
-      - Test improvements
-      - Update dependencies
-
-2.1.0 - Reports service
-      - Unify with Report request and response interfaces
-      - Add service name and method name metadata into Response
-
-2.0.1 - Update examples
-
-2.0.0 - Transport and ServiceFactory refactoring
-      - Improve Client class constructor
-      - Add transport and credentials setters to Client class
-
-1.1.0 - Add changelog
-      - Prepare transport for AgencyClients service
-      - AgencyClient service
diff --git a/examples/agency_clients.php b/examples/agency_clients.php
index 9d5a99f..b56aaac 100644
--- a/examples/agency_clients.php
+++ b/examples/agency_clients.php
@@ -2,10 +2,9 @@
 
 require '../vendor/autoload.php';
 
-$credentials = \Gladyshev\Yandex\Direct\AgencyCredentials::buildForSandbox(
+$credentials = \Gladyshev\Yandex\Direct\Credentials::agencySandbox(
     getenv('_TOKEN_'),
-    getenv('_MASTER_TOKEN_'),
-    getenv('_CLIENT_LOGIN_')
+    getenv('_MASTER_TOKEN_')
 );
 
 $client = new \Gladyshev\Yandex\Direct\Client(
@@ -14,7 +13,7 @@
 );
 
 $resp = $client->agencyClients->get(
-    ['Archived' => 'YES'],
+    ['Archived' => 'NO'],
     ['Login']
 );
 
diff --git a/examples/reports.php b/examples/reports.php
index 8744b76..f94f18e 100644
--- a/examples/reports.php
+++ b/examples/reports.php
@@ -2,7 +2,7 @@
 
 require '../vendor/autoload.php';
 
-$credentials = \Gladyshev\Yandex\Direct\ClientCredentials::buildForSandbox(
+$credentials = \Gladyshev\Yandex\Direct\Credentials::clientSandbox(
     getenv('_TOKEN_'),
     getenv('_MASTER_TOKEN_')
 );
diff --git a/examples/simple.php b/examples/simple.php
index 5536599..0a9d3d9 100644
--- a/examples/simple.php
+++ b/examples/simple.php
@@ -2,7 +2,7 @@
 
 require '../vendor/autoload.php';
 
-$credentials = \Gladyshev\Yandex\Direct\ClientCredentials::buildForSandbox(
+$credentials = \Gladyshev\Yandex\Direct\Credentials::clientSandbox(
     getenv('_TOKEN_'),
     getenv('_MASTER_TOKEN_')
 );
diff --git a/phpcs.xml b/phpcs.xml
index 78d2747..c30965f 100644
--- a/phpcs.xml
+++ b/phpcs.xml
@@ -7,7 +7,7 @@
     <arg name="colors"/>
 
     <!-- inherit rules from: PSR-2 -->
-    <rule ref="PSR2">
+    <rule ref="PSR12">
         <exclude name="PSR1.Classes.ClassDeclaration"/>
         <exclude name="PSR1.Files.SideEffects"/>
         <exclude name="Squiz.WhiteSpace.SuperfluousWhitespace"/>
@@ -15,7 +15,7 @@
     </rule>
 
     <!-- Paths to check -->
-    <file>src</file>
+    <file>src/</file>
 
     <!-- Exclude -->
     <exclude-pattern>*/vendor/*</exclude-pattern>
diff --git a/src/AbstractService.php b/src/AbstractService.php
index 2a72a64..a3f8d2e 100644
--- a/src/AbstractService.php
+++ b/src/AbstractService.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct;
@@ -30,16 +31,6 @@ public function __construct(
         $this->httpClient = $httpClient;
     }
 
-    public function getName(): string
-    {
-        return $this->serviceName;
-    }
-
-    public function getCredentials(): \Gladyshev\Yandex\Direct\CredentialsInterface
-    {
-        return $this->credentials;
-    }
-
     public function call(array $params = []): array
     {
         $request = new \GuzzleHttp\Psr7\Request(
@@ -54,12 +45,22 @@ public function call(array $params = []): array
         return $this->handleResponse($request, $response);
     }
 
+    protected function getServiceName(): string
+    {
+        return $this->serviceName;
+    }
+
+    protected function getCredentials(): \Gladyshev\Yandex\Direct\CredentialsInterface
+    {
+        return $this->credentials;
+    }
+
     /**
      * @return string
      */
-    protected function getUri() : string
+    protected function getUri(): string
     {
-        return $this->getCredentials()->getBaseUrl() . '/json/v5/' . mb_strtolower($this->getName());
+        return $this->getCredentials()->getBaseUrl() . '/json/v5/' . mb_strtolower($this->getServiceName());
     }
 
     /**
@@ -91,7 +92,7 @@ protected function getHeaders(): array
     protected function getBody(array $params): string
     {
         if (empty($params['params'])) {
-            $params = new \StdClass;
+            $params = new \StdClass();
         } else {
             $params['params'] = array_filter($params['params']);
         }
diff --git a/src/AgencyCredentials.php b/src/AgencyCredentials.php
deleted file mode 100644
index b222042..0000000
--- a/src/AgencyCredentials.php
+++ /dev/null
@@ -1,101 +0,0 @@
-<?php
-declare(strict_types=1);
-
-namespace Gladyshev\Yandex\Direct;
-
-final class AgencyCredentials implements \Gladyshev\Yandex\Direct\CredentialsInterface
-{
-    private $token;
-    private $masterToken;
-    private $login;
-    private $useOperatorUnits;
-    private $language;
-    private $baseUrl;
-
-    public function __construct(
-        string $token,
-        ?string $masterToken,
-        ?string $clientLogin,
-        ?bool $useOperatorUnits,
-        string $language,
-        string $baseUrl
-    ) {
-        $this->token = $token;
-        $this->masterToken = $masterToken;
-        $this->login = $clientLogin;
-        $this->useOperatorUnits = $useOperatorUnits;
-        $this->language = $language;
-        $this->baseUrl = $baseUrl;
-    }
-
-    public static function buildForSandbox(
-        string $token,
-        ?string $masterToken = null,
-        ?string $login = null,
-        ?bool $useOperatorUnits = true,
-        string $language = self::LANGUAGE_RU,
-        string $baseUrl = self::DEFAULT_SANDBOX_BASE_URL
-    ): self {
-        return new self(
-            $token,
-            $masterToken,
-            $login,
-            $useOperatorUnits,
-            $language,
-            $baseUrl
-        );
-    }
-
-    /**
-     * @return string
-     */
-    public function getToken(): string
-    {
-        return $this->token;
-    }
-
-    /**
-     * @return string|null
-     */
-    public function getMasterToken(): ?string
-    {
-        return $this->masterToken;
-    }
-
-    /**
-     * @return string|null
-     */
-    public function getClientLogin(): ?string
-    {
-        return $this->login;
-    }
-
-    /**
-     * @return bool|null
-     */
-    public function getUseOperatorUnits(): ?bool
-    {
-        return $this->useOperatorUnits;
-    }
-
-    /**
-     * @return string
-     */
-    public function getLanguage(): string
-    {
-        return $this->language;
-    }
-
-    /**
-     * @return string
-     */
-    public function getBaseUrl(): string
-    {
-        return $this->baseUrl;
-    }
-
-    public function isAgency(): bool
-    {
-        return true;
-    }
-}
diff --git a/src/Client.php b/src/Client.php
index 6763e66..4a33b50 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct;
diff --git a/src/ClientCredentials.php b/src/ClientCredentials.php
deleted file mode 100644
index f5c3dd4..0000000
--- a/src/ClientCredentials.php
+++ /dev/null
@@ -1,114 +0,0 @@
-<?php
-declare(strict_types=1);
-
-namespace Gladyshev\Yandex\Direct;
-
-final class ClientCredentials implements CredentialsInterface
-{
-    /**
-     * @var string
-     */
-    private $token;
-
-    /**
-     * @var string|null
-     */
-    private $masterToken;
-
-    /**
-     * @var string
-     */
-    private $language;
-
-    /**
-     * @var string
-     */
-    private $baseUrl;
-
-    public function __construct(
-        string $token,
-        ?string $masterToken,
-        string $language,
-        string $baseUrl
-    ) {
-        $this->token = $token;
-        $this->masterToken = $masterToken;
-        $this->language = $language;
-        $this->baseUrl = $baseUrl;
-    }
-
-    public static function build(
-        string $token,
-        ?string $masterToken = null,
-        string $language = self::LANGUAGE_RU,
-        string $baseUrl = self::DEFAULT_BASE_URL
-    ): self {
-        return new self(
-            $token,
-            $masterToken,
-            $language,
-            $baseUrl
-        );
-    }
-
-    public static function buildForSandbox(
-        string $token,
-        ?string $masterToken = null,
-        string $language = self::LANGUAGE_RU,
-        string $baseUrl = self::DEFAULT_SANDBOX_BASE_URL
-    ): self {
-        return new self(
-            $token,
-            $masterToken,
-            $language,
-            $baseUrl
-        );
-    }
-
-    /**
-     * @return string
-     */
-    public function getToken(): string
-    {
-        return $this->token;
-    }
-
-    /**
-     * @return string|null
-     */
-    public function getMasterToken(): ?string
-    {
-        return $this->masterToken;
-    }
-
-    /**
-     * @return string
-     */
-    public function getLanguage(): string
-    {
-        return $this->language;
-    }
-
-    /**
-     * @return string
-     */
-    public function getBaseUrl(): string
-    {
-        return $this->baseUrl;
-    }
-
-    public function getClientLogin(): ?string
-    {
-        return null;
-    }
-
-    public function getUseOperatorUnits(): ?bool
-    {
-        return null;
-    }
-
-    public function isAgency(): bool
-    {
-        return false;
-    }
-}
diff --git a/src/Credentials.php b/src/Credentials.php
new file mode 100644
index 0000000..52d1e47
--- /dev/null
+++ b/src/Credentials.php
@@ -0,0 +1,169 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Gladyshev\Yandex\Direct;
+
+final class Credentials implements \Gladyshev\Yandex\Direct\CredentialsInterface
+{
+    private $token;
+    private $masterToken;
+    private $login;
+    private $useOperatorUnits;
+    private $isAgency;
+    private $language;
+    private $baseUrl;
+
+    /**
+     * Credentials constructor.
+     *
+     * @param string $token                 # OAuth2 токен доступа
+     * @param string|null $masterToken      # Токен для финансовых операций (не поддерживается API V5)
+     * @param string|null $clientLogin      # Логин клиента Агентства (если isAgency = true, иначе NULL)
+     * @param bool|null $useOperatorUnits   # Расходовать баллы агентства (если isAgency = true, иначе NULL)
+     * @param bool $isAgency                # Аккаунт Агентства или Клиента
+     * @param string $language              # Язык в тексте ответов
+     * @param string $baseUrl               # URL сервера API
+     */
+    public function __construct(
+        string $token,
+        ?string $masterToken,
+        ?string $clientLogin,
+        ?bool $useOperatorUnits,
+        bool $isAgency,
+        string $language,
+        string $baseUrl
+    ) {
+        $this->token = $token;
+        $this->masterToken = $masterToken;
+        $this->login = $clientLogin;
+        $this->useOperatorUnits = $useOperatorUnits;
+        $this->language = $language;
+        $this->baseUrl = $baseUrl;
+        $this->isAgency = $isAgency;
+    }
+
+    public static function agency(
+        string $token,
+        ?string $masterToken = null,
+        ?string $login = null,
+        bool $useOperatorUnits = true,
+        string $language = self::LANGUAGE_RU
+    ): self {
+        return new self(
+            $token,
+            $masterToken,
+            $login,
+            $useOperatorUnits,
+            true,
+            $language,
+            self::DEFAULT_BASE_URL
+        );
+    }
+
+    public static function agencySandbox(
+        string $token,
+        ?string $masterToken = null,
+        ?string $login = null,
+        bool $useOperatorUnits = true,
+        string $language = self::LANGUAGE_RU
+    ): self {
+        return new self(
+            $token,
+            $masterToken,
+            $login,
+            $useOperatorUnits,
+            true,
+            $language,
+            self::DEFAULT_SANDBOX_BASE_URL
+        );
+    }
+
+    public static function client(
+        string $token,
+        ?string $masterToken = null,
+        string $language = self::LANGUAGE_RU
+    ): self {
+        return new self(
+            $token,
+            $masterToken,
+            null,
+            null,
+            false,
+            $language,
+            self::DEFAULT_BASE_URL
+        );
+    }
+
+    public static function clientSandbox(
+        string $token,
+        ?string $masterToken = null,
+        string $language = self::LANGUAGE_RU
+    ): self {
+        return new self(
+            $token,
+            $masterToken,
+            null,
+            null,
+            false,
+            $language,
+            self::DEFAULT_SANDBOX_BASE_URL
+        );
+    }
+
+    /**
+     * @return string
+     */
+    public function getToken(): string
+    {
+        return $this->token;
+    }
+
+    /**
+     * @return string|null
+     */
+    public function getMasterToken(): ?string
+    {
+        return $this->masterToken;
+    }
+
+    /**
+     * @return string|null
+     */
+    public function getClientLogin(): ?string
+    {
+        return $this->login;
+    }
+
+    /**
+     * @return bool|null
+     */
+    public function getUseOperatorUnits(): ?bool
+    {
+        return $this->useOperatorUnits;
+    }
+
+    /**
+     * @return string
+     */
+    public function getLanguage(): string
+    {
+        return $this->language;
+    }
+
+    /**
+     * @return string
+     */
+    public function getBaseUrl(): string
+    {
+        return $this->baseUrl;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isAgency(): bool
+    {
+        return $this->isAgency;
+    }
+}
diff --git a/src/Exception/ErrorResponseException.php b/src/Exception/ErrorResponseException.php
index c73b37a..8f8466d 100644
--- a/src/Exception/ErrorResponseException.php
+++ b/src/Exception/ErrorResponseException.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct\Exception;
diff --git a/src/Exception/ServiceNotFoundException.php b/src/Exception/ServiceNotFoundException.php
index 536b6e2..b4192a9 100644
--- a/src/Exception/ServiceNotFoundException.php
+++ b/src/Exception/ServiceNotFoundException.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct\Exception;
diff --git a/src/Service/AdGroups.php b/src/Service/AdGroups.php
index 317fc1d..24a4b3c 100644
--- a/src/Service/AdGroups.php
+++ b/src/Service/AdGroups.php
@@ -4,7 +4,6 @@
 
 use ReflectionException;
 use Gladyshev\Yandex\Direct\Exception\ErrorResponseException;
-use Gladyshev\Yandex\Direct\AbstractService;
 
 use function Gladyshev\Yandex\Direct\get_param_names;
 
@@ -12,7 +11,7 @@
  * Class AdGroups
  * @package Gladyshev\Yandex\Direct\Service
  */
-final class AdGroups extends AbstractService
+final class AdGroups extends \Gladyshev\Yandex\Direct\AbstractService
 {
     /**
      * Создает группы объявлений.
diff --git a/src/Service/AdImages.php b/src/Service/AdImages.php
index c7171a2..7f36a10 100644
--- a/src/Service/AdImages.php
+++ b/src/Service/AdImages.php
@@ -2,8 +2,6 @@
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/Ads.php b/src/Service/Ads.php
index 8100815..739ae1c 100644
--- a/src/Service/Ads.php
+++ b/src/Service/Ads.php
@@ -1,14 +1,9 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 26/08/2016 13:51
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
 use ReflectionException;
 
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/AgencyClients.php b/src/Service/AgencyClients.php
index 4857d6a..76f7011 100644
--- a/src/Service/AgencyClients.php
+++ b/src/Service/AgencyClients.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct\Service;
diff --git a/src/Service/AudienceTargets.php b/src/Service/AudienceTargets.php
index 7ae8a8c..cb02bb3 100644
--- a/src/Service/AudienceTargets.php
+++ b/src/Service/AudienceTargets.php
@@ -1,13 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @created 08.12.16 16:07
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/BidModifiers.php b/src/Service/BidModifiers.php
index 53f1938..34017fe 100644
--- a/src/Service/BidModifiers.php
+++ b/src/Service/BidModifiers.php
@@ -4,7 +4,6 @@
 
 use Gladyshev\Yandex\Direct\Exception\ErrorResponseException;
 
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/Bids.php b/src/Service/Bids.php
index 308f7ea..29645e9 100644
--- a/src/Service/Bids.php
+++ b/src/Service/Bids.php
@@ -1,13 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 29/08/2016 12:32
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/Businesses.php b/src/Service/Businesses.php
index 64a7d9c..9243706 100644
--- a/src/Service/Businesses.php
+++ b/src/Service/Businesses.php
@@ -1,12 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 26/08/20120 21:16
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/Campaigns.php b/src/Service/Campaigns.php
index 5043700..f5280dc 100644
--- a/src/Service/Campaigns.php
+++ b/src/Service/Campaigns.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct\Service;
diff --git a/src/Service/Changes.php b/src/Service/Changes.php
index 471419b..5ead314 100644
--- a/src/Service/Changes.php
+++ b/src/Service/Changes.php
@@ -1,14 +1,9 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 29/08/2016 12:33
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
 use ReflectionException;
 
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/Clients.php b/src/Service/Clients.php
index 7c3db8c..8c37b3d 100644
--- a/src/Service/Clients.php
+++ b/src/Service/Clients.php
@@ -1,14 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @created 29.11.16 14:09
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
-
 /**
  * Class Clients
  * @package Gladyshev\Yandex\Direct\Service
diff --git a/src/Service/Creatives.php b/src/Service/Creatives.php
index 66f898e..f9ab7fb 100644
--- a/src/Service/Creatives.php
+++ b/src/Service/Creatives.php
@@ -1,7 +1,4 @@
 <?php
-/**
- * @project yandex-direct-client
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
@@ -9,7 +6,6 @@
 use ReflectionException;
 use Gladyshev\Yandex\Direct\Exception\ErrorResponseException;
 
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/Dictionaries.php b/src/Service/Dictionaries.php
index a7b805d..770c8af 100644
--- a/src/Service/Dictionaries.php
+++ b/src/Service/Dictionaries.php
@@ -1,14 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 29/08/2016 12:33
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
-
 /**
  * Class Dictionaries
  * @package Gladyshev\Yandex\Direct\Service
diff --git a/src/Service/DynamicTextAdTargets.php b/src/Service/DynamicTextAdTargets.php
index e6f9d67..488a737 100644
--- a/src/Service/DynamicTextAdTargets.php
+++ b/src/Service/DynamicTextAdTargets.php
@@ -1,13 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 29/08/2016 12:34
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/Feeds.php b/src/Service/Feeds.php
index af4fe0f..e1b83f5 100644
--- a/src/Service/Feeds.php
+++ b/src/Service/Feeds.php
@@ -1,15 +1,10 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 26/08/20120 21:34
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
 use ReflectionException;
 use Gladyshev\Yandex\Direct\Exception\ErrorResponseException;
 
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/KeywordBids.php b/src/Service/KeywordBids.php
index b529ce1..9972d18 100644
--- a/src/Service/KeywordBids.php
+++ b/src/Service/KeywordBids.php
@@ -1,13 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 23/04/2018 09:50
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/Keywords.php b/src/Service/Keywords.php
index 603050b..fde7e91 100644
--- a/src/Service/Keywords.php
+++ b/src/Service/Keywords.php
@@ -1,13 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 29/08/2016 12:34
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/KeywordsResearch.php b/src/Service/KeywordsResearch.php
index 9b93b96..65a3983 100644
--- a/src/Service/KeywordsResearch.php
+++ b/src/Service/KeywordsResearch.php
@@ -1,14 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 03.05.17 7:46
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
-
 final class KeywordsResearch extends \Gladyshev\Yandex\Direct\AbstractService
 {
     /**
diff --git a/src/Service/Leads.php b/src/Service/Leads.php
index e305d81..9e65115 100644
--- a/src/Service/Leads.php
+++ b/src/Service/Leads.php
@@ -1,14 +1,9 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 23/04/2018 10:12
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
 use ReflectionException;
 
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/NegativeKeywordSharedSets.php b/src/Service/NegativeKeywordSharedSets.php
index 8606aa6..a8e6091 100644
--- a/src/Service/NegativeKeywordSharedSets.php
+++ b/src/Service/NegativeKeywordSharedSets.php
@@ -1,11 +1,7 @@
 <?php
-/**
- * @project yandex-direct-client
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/Reports.php b/src/Service/Reports.php
index d1a2fce..094c3c7 100644
--- a/src/Service/Reports.php
+++ b/src/Service/Reports.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct\Service;
@@ -141,7 +142,8 @@ protected function handleResponse(
             'request_id' => current($response->getHeader('RequestId'))
         ];
 
-        if ($response->getStatusCode() == 201
+        if (
+            $response->getStatusCode() == 201
             || $response->getStatusCode() == 202
         ) {
             $result['retryIn'] = $response->getHeaders()['retryIn'];
diff --git a/src/Service/RetargetingLists.php b/src/Service/RetargetingLists.php
index 27cb146..245f410 100644
--- a/src/Service/RetargetingLists.php
+++ b/src/Service/RetargetingLists.php
@@ -1,13 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @created 03.12.16 15:26
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/Sitelinks.php b/src/Service/Sitelinks.php
index c8247db..ead759d 100644
--- a/src/Service/Sitelinks.php
+++ b/src/Service/Sitelinks.php
@@ -1,13 +1,7 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 29/08/2016 12:34
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/SmartAdTargets.php b/src/Service/SmartAdTargets.php
index 9148fdb..633b30d 100644
--- a/src/Service/SmartAdTargets.php
+++ b/src/Service/SmartAdTargets.php
@@ -1,15 +1,10 @@
 <?php
-/**
- * @author Dmitry Gladyshev <deel@email.ru>
- * @date 26/08/20120 21:34
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
 use ReflectionException;
 use Gladyshev\Yandex\Direct\Exception\ErrorResponseException;
 
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/TurboPages.php b/src/Service/TurboPages.php
index 5f3d582..e286a19 100644
--- a/src/Service/TurboPages.php
+++ b/src/Service/TurboPages.php
@@ -1,11 +1,7 @@
 <?php
-/**
- * @project yandex-direct-client
- */
 
 namespace Gladyshev\Yandex\Direct\Service;
 
-
 use function Gladyshev\Yandex\Direct\get_param_names;
 
 /**
diff --git a/src/Service/VCards.php b/src/Service/VCards.php
index 3448a12..91b093c 100644
--- a/src/Service/VCards.php
+++ b/src/Service/VCards.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct\Service;
diff --git a/src/ServiceFactoryInterface.php b/src/ServiceFactoryInterface.php
index 0b6de08..da4c6b2 100644
--- a/src/ServiceFactoryInterface.php
+++ b/src/ServiceFactoryInterface.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct;
diff --git a/src/ServiceInterface.php b/src/ServiceInterface.php
index 9eca086..43acc2f 100644
--- a/src/ServiceInterface.php
+++ b/src/ServiceInterface.php
@@ -1,11 +1,10 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct;
 
 interface ServiceInterface
 {
-    public function getName(): string;
-    public function getCredentials(): \Gladyshev\Yandex\Direct\CredentialsInterface;
     public function call(array $params = []): array;
 }
diff --git a/tests/ClientTest.php b/tests/ClientTest.php
index 016de49..532e01e 100644
--- a/tests/ClientTest.php
+++ b/tests/ClientTest.php
@@ -1,14 +1,10 @@
 <?php
-/**
- * @project yandex-direct-client
- */
+declare(strict_types=1);
 
 namespace Gladyshev\Yandex\Direct\Tests;
 
-use Gladyshev\Yandex\Direct\Client;
 use Gladyshev\Yandex\Direct\Exception\ServiceNotFoundException;
 use Gladyshev\Yandex\Direct\ServiceInterface;
-use Gladyshev\Yandex\Direct\Tests\Mocks\Credentials;
 use PHPUnit\Framework\TestCase;
 
 class ClientTest extends TestCase
@@ -17,10 +13,10 @@ class ClientTest extends TestCase
 
     public function setUp(): void
     {
-        $credentials = new Credentials;
-        $httpClient = new \GuzzleHttp\Client();
-
-        $this->client = new Client($credentials, $httpClient);
+        $this->client = new \Gladyshev\Yandex\Direct\Client(
+            new \Gladyshev\Yandex\Direct\Tests\Mocks\Credentials,
+            new \GuzzleHttp\Client
+        );
     }
 
     /**
@@ -33,6 +29,16 @@ public function testCreateService(string $serviceName): void
         $this->assertInstanceOf(ServiceInterface::class, $instance);
     }
 
+    /**
+     * @dataProvider validServicesDataProvider
+     */
+    public function testMagicCreateService(string $serviceName): void
+    {
+        $instance = $this->client->{$serviceName};
+
+        $this->assertInstanceOf(ServiceInterface::class, $instance);
+    }
+
     /**
      * @dataProvider invalidServicesDataProvider
      */
@@ -42,43 +48,38 @@ public function testExceptionOnInvalidServiceName(string $serviceName): void
         $this->client->createService($serviceName);
     }
 
+    /**
+     * @dataProvider invalidServicesDataProvider
+     */
+    public function testExceptionOnInvalidServiceNameWithMagicCreate(string $serviceName): void
+    {
+        $this->expectException(ServiceNotFoundException::class);
+        $this->client->{$serviceName};
+    }
+
     public function invalidServicesDataProvider(): array
     {
         return [
-            ['fuck'],
-            ['nop'],
-            ['piu']
+            ['foo'],
+            ['bar'],
+            ['buzz']
         ];
     }
 
     public function validServicesDataProvider(): array
     {
-        return [
-            ['AdExtensions'],
-            ['AdGroups'],
-            ['AdImages'],
-            ['Ads'],
-            ['AgencyClients'],
-            ['AudienceTargets'],
-            ['BidModifiers'],
-            ['Bids'],
-            ['Businesses'],
-            ['Campaigns'],
-            ['Changes'],
-            ['Clients'],
-            ['Creatives'],
-            ['Dictionaries'],
-            ['DynamicTextAdTargets'],
-            ['KeywordBids'],
-            ['Keywords'],
-            ['KeywordsResearch'],
-            ['Leads'],
-            ['NegativeKeywordSharedSets'],
-            ['Reports'],
-            ['RetargetingLists'],
-            ['Sitelinks'],
-            ['TurboPages'],
-            ['VCards'],
-        ];
+        $dir = new \FilesystemIterator(
+            dirname(__DIR__) . DIRECTORY_SEPARATOR . 'src' . DIRECTORY_SEPARATOR . 'Service'
+        );
+
+        $services = [];
+
+        foreach ($dir as $fileInfo) {
+            if ($fileInfo->isFile()) {
+                $services[] = [$fileInfo->getBasename('.php')];
+            }
+        }
+
+        return $services;
     }
 }
diff --git a/tests/CredentialsTest.php b/tests/CredentialsTest.php
new file mode 100644
index 0000000..332cd1d
--- /dev/null
+++ b/tests/CredentialsTest.php
@@ -0,0 +1,137 @@
+<?php
+/**
+ * @project yandex-direct-client
+ */
+
+namespace Gladyshev\Yandex\Direct\Tests;
+
+use Gladyshev\Yandex\Direct\Credentials;
+use Gladyshev\Yandex\Direct\CredentialsInterface;
+use PHPUnit\Framework\TestCase;
+
+class CredentialsTest extends TestCase
+{
+    private $credentials;
+
+    public function setUp(): void
+    {
+        $this->credentials = new Credentials(
+            'token',
+            'masterToken',
+            'clientLogin',
+            true,
+            true,
+            'language',
+            'baseUrl'
+        );
+    }
+
+    public function testGetToken()
+    {
+        $this->assertEquals('token', $this->credentials->getToken());
+    }
+
+    public function testGetUseOperatorUnits()
+    {
+        $this->assertEquals(true, $this->credentials->getUseOperatorUnits());
+    }
+
+    public function testGetClientLogin()
+    {
+        $this->assertEquals('clientLogin', $this->credentials->getClientLogin());
+    }
+
+    public function testGetMasterToken()
+    {
+        $this->assertEquals('masterToken', $this->credentials->getMasterToken());
+    }
+
+    public function testIsAgency()
+    {
+        $this->assertEquals(true, $this->credentials->isAgency());
+    }
+
+    public function testGetLanguage()
+    {
+        $this->assertEquals('language', $this->credentials->getLanguage());
+    }
+
+    public function testGetBaseUrl()
+    {
+        $this->assertEquals('baseUrl', $this->credentials->getBaseUrl());
+    }
+
+    public function testAgency()
+    {
+        $credentials = \Gladyshev\Yandex\Direct\Credentials::agency(
+            'token',
+            'masterToken',
+            'login',
+            true,
+            'language'
+        );
+
+        $this->assertInstanceOf(CredentialsInterface::class, $credentials);
+        $this->assertEquals(true, $credentials->isAgency());
+        $this->assertEquals(CredentialsInterface::DEFAULT_BASE_URL, $credentials->getBaseUrl());
+        $this->assertEquals('token', $credentials->getToken());
+        $this->assertEquals('masterToken', $credentials->getMasterToken());
+        $this->assertEquals('login', $credentials->getClientLogin());
+        $this->assertEquals('language', $credentials->getLanguage());
+    }
+
+    public function testAgencySandbox()
+    {
+        $credentials = \Gladyshev\Yandex\Direct\Credentials::agencySandbox(
+            'token',
+            'masterToken',
+            'login',
+            true,
+            'language'
+        );
+
+        $this->assertInstanceOf(CredentialsInterface::class, $credentials);
+        $this->assertEquals(true, $credentials->isAgency());
+        $this->assertEquals(CredentialsInterface::DEFAULT_SANDBOX_BASE_URL, $credentials->getBaseUrl());
+        $this->assertEquals('token', $credentials->getToken());
+        $this->assertEquals('masterToken', $credentials->getMasterToken());
+        $this->assertEquals('login', $credentials->getClientLogin());
+        $this->assertEquals('language', $credentials->getLanguage());
+    }
+
+    public function testClient()
+    {
+        $credentials = \Gladyshev\Yandex\Direct\Credentials::client(
+            'token',
+            'masterToken',
+            'language'
+        );
+
+        $this->assertInstanceOf(CredentialsInterface::class, $credentials);
+        $this->assertEquals(false, $credentials->isAgency());
+        $this->assertEquals(CredentialsInterface::DEFAULT_BASE_URL, $credentials->getBaseUrl());
+        $this->assertEquals('token', $credentials->getToken());
+        $this->assertEquals('masterToken', $credentials->getMasterToken());
+        $this->assertEquals(null, $credentials->getClientLogin());
+        $this->assertEquals(null, $credentials->getUseOperatorUnits());
+        $this->assertEquals('language', $credentials->getLanguage());
+    }
+
+    public function testClientSandbox()
+    {
+        $credentials = Credentials::clientSandbox(
+            'token',
+            'masterToken',
+            'language'
+        );
+
+        $this->assertInstanceOf(CredentialsInterface::class, $credentials);
+        $this->assertEquals(false, $credentials->isAgency());
+        $this->assertEquals(CredentialsInterface::DEFAULT_SANDBOX_BASE_URL, $credentials->getBaseUrl());
+        $this->assertEquals('token', $credentials->getToken());
+        $this->assertEquals('masterToken', $credentials->getMasterToken());
+        $this->assertEquals(null, $credentials->getClientLogin());
+        $this->assertEquals(null, $credentials->getUseOperatorUnits());
+        $this->assertEquals('language', $credentials->getLanguage());
+    }
+}