diff --git a/src/BaseClientInterface.php b/src/BaseClientInterface.php
new file mode 100644
index 0000000..62f320c
--- /dev/null
+++ b/src/BaseClientInterface.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace HadesArchitect\UnitedDomains;
+
+use HadesArchitect\UnitedDomains\Exception\ApiException;
+
+interface BaseClientInterface
+{
+    /**
+     * @param $method
+     * @param array $properties
+     * @throws ApiException
+     * @return ResponseInterface
+     */
+    public function call($method, array $properties = []): ResponseInterface;
+}
\ No newline at end of file
diff --git a/src/Client.php b/src/Client.php
index 56eedb5..78a7ae4 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -4,14 +4,16 @@
 
 use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Client as HTTPClient;
+use GuzzleHttp\Exception\GuzzleException;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\Psr7\Uri;
+use HadesArchitect\UnitedDomains\Exception\ApiException;
 use HadesArchitect\UnitedDomains\Exception\InvalidResponseFormatException;
 use HadesArchitect\UnitedDomains\Exception\ServerException;
 use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\UriInterface;
 
-class Client
+class Client implements BaseClientInterface
 {
     /**
      * @var ClientInterface
@@ -23,7 +25,7 @@ class Client
      */
     protected $uri;
 
-    public function __construct($username, $password)
+    public function __construct($username, $password, ClientInterface $httpClient = null)
     {
         $this->uri = Uri::fromParts([
             'scheme' => 'https',
@@ -32,9 +34,16 @@ public function __construct($username, $password)
             'query' => sprintf('s_login=%s&s_pw=%s', $username, $password)
         ]);
 
-        $this->httpClient = new HTTPClient();
+        if (null === $httpClient) {
+            $httpClient = new HTTPClient();
+        }
+
+        $this->httpClient = $httpClient;
     }
 
+    /**
+     * @inheritdoc
+     */
     public function call($method, array $properties = []): ResponseInterface
     {
         $query = sprintf(
@@ -44,7 +53,11 @@ public function call($method, array $properties = []): ResponseInterface
             http_build_query($properties)
         );
 
-        $body = $this->doCall(new Request('get', $this->uri->withQuery($query)));
+        try {
+            $body = $this->doCall(new Request('get', $this->uri->withQuery($query)));
+        } catch (GuzzleException $guzzleException) {
+            throw new ApiException('An error occured during API call', 0, $guzzleException);
+        }
 
         $this->validateResponse($body);
 
@@ -59,6 +72,7 @@ public function call($method, array $properties = []): ResponseInterface
 
     /**
      * @param RequestInterface $request
+     * @throws GuzzleException
      * @return string
      */
     protected function doCall(RequestInterface $request): string
diff --git a/src/ClientFacade.php b/src/ClientFacade.php
index a43adb0..ccdc6f3 100644
--- a/src/ClientFacade.php
+++ b/src/ClientFacade.php
@@ -6,11 +6,10 @@
 use HadesArchitect\UnitedDomains\Exception\InvalidParameterException;
 use HadesArchitect\UnitedDomains\Exception\ServerException;
 
-class ClientFacade extends TraceableClient
+class ClientFacade extends TraceableClient implements ClientInterface
 {
     /**
-     * @param string $domain
-     * @return bool
+     * @inheritdoc
      */
     public function isDomainFree(string $domain): bool
     {
@@ -26,9 +25,7 @@ public function isDomainFree(string $domain): bool
     }
 
     /**
-     * @param string $zone
-     * @param string $soamname
-     * @param string $soarname
+     * @inheritdoc
      */
     public function CreateDNSZone(string $zone, string $soamname = '', string $soarname = ''): void
     {
@@ -43,7 +40,7 @@ public function CreateDNSZone(string $zone, string $soamname = '', string $soarn
     }
 
     /**
-     * @param string $zone
+     * @inheritdoc
      */
     public function DeleteDNSZone(string $zone): void
     {
@@ -51,12 +48,7 @@ public function DeleteDNSZone(string $zone): void
     }
 
     /**
-     * @param string $zone
-     * @param string $name
-     * @param string $type
-     * @param string $data
-     * @param int $ttl
-     * @param string $class
+     * @inheritdoc
      */
     public function addRecord(string $zone, string $name, string $type, string $data, int $ttl = 3600, string $class = 'IN')
     {
@@ -70,9 +62,7 @@ public function addRecord(string $zone, string $name, string $type, string $data
     }
 
     /**
-     * @param string $zone
-     * @param array $records
-     * @throws InvalidParameterException
+     * @inheritdoc
      */
     public function addRecords(string $zone, array $records)
     {
@@ -100,11 +90,7 @@ public function addRecords(string $zone, array $records)
     }
 
     /**
-     * @param string $zone
-     * @param string $name
-     * @param string $type
-     * @param string|bool $data
-     * @param string $class
+     * @inheritdoc
      */
     public function deleteRecord(string $zone, string $name, string $type, $data = false, string $class = 'IN'): void
     {
@@ -134,8 +120,7 @@ function ($record) use ($name) {
     }
 
     /**
-     * @param string $zone
-     * @return array
+     * @inheritdoc
      */
     public function getRecords(string $zone)
     {
@@ -143,10 +128,7 @@ public function getRecords(string $zone)
     }
 
     /**
-     * @param string $zone
-     * @param string $type
-     *
-     * @return array
+     * @inheritdoc
      */
     public function findRecordsByType(string $zone, string $type)
     {
@@ -171,11 +153,11 @@ function ($record) {
                 preg_match_all("/(\S+)\s(\d+)\s(\S+)\s(\S+)\s(.*)/", $record, $matches);
 
                 return [
-                    'name' => $matches[1][0],
-                    'ttl' => (int)$matches[2][0],
+                    'name'  => $matches[1][0],
+                    'ttl'   => (int)$matches[2][0],
                     'class' => $matches[3][0],
-                    'type' => $matches[4][0],
-                    'data' => $matches[5][0]
+                    'type'  => $matches[4][0],
+                    'data'  => $matches[5][0]
                 ];
             },
             $this->call('QueryDNSZoneRRList', ['dnszone' => $zone])->getProperty('rr')
diff --git a/src/ClientInterface.php b/src/ClientInterface.php
new file mode 100644
index 0000000..7a6c238
--- /dev/null
+++ b/src/ClientInterface.php
@@ -0,0 +1,66 @@
+<?php
+
+namespace HadesArchitect\UnitedDomains;
+
+use HadesArchitect\UnitedDomains\Exception\InvalidParameterException;
+
+interface ClientInterface extends BaseClientInterface
+{
+    /**
+     * @param string $domain
+     * @return bool
+     */
+    public function isDomainFree(string $domain): bool;
+
+    /**
+     * @param string $zone
+     * @param string $soamname
+     * @param string $soarname
+     */
+    public function CreateDNSZone(string $zone, string $soamname = '', string $soarname = ''): void;
+
+    /**
+     * @param string $zone
+     */
+    public function DeleteDNSZone(string $zone): void;
+
+    /**
+     * @param string $zone
+     * @param string $name
+     * @param string $type
+     * @param string $data
+     * @param int $ttl
+     * @param string $class
+     */
+    public function addRecord(string $zone, string $name, string $type, string $data, int $ttl = 3600, string $class = 'IN');
+
+    /**
+     * @param string $zone
+     * @param array $records
+     * @throws InvalidParameterException
+     */
+    public function addRecords(string $zone, array $records);
+
+    /**
+     * @param string $zone
+     * @param string $name
+     * @param string $type
+     * @param string|bool $data
+     * @param string $class
+     */
+    public function deleteRecord(string $zone, string $name, string $type, $data = false, string $class = 'IN'): void;
+
+    /**
+     * @param string $zone
+     * @return array
+     */
+    public function getRecords(string $zone);
+
+    /**
+     * @param string $zone
+     * @param string $type
+     *
+     * @return array
+     */
+    public function findRecordsByType(string $zone, string $type);
+}
\ No newline at end of file