diff --git a/Controller/ApiController.php b/Controller/ApiController.php
index c04821f..bcecaf1 100755
--- a/Controller/ApiController.php
+++ b/Controller/ApiController.php
@@ -14,12 +14,15 @@ declare(strict_types=1);
 
 namespace Modules\Exchange\Controller;
 
+use Modules\Exchange\Models\InterfaceManager;
 use Modules\Exchange\Models\InterfaceManagerMapper;
 use Modules\Media\Models\UploadFile;
 use phpOMS\Message\NotificationLevel;
 use phpOMS\Message\RequestAbstract;
 use phpOMS\Message\ResponseAbstract;
 use phpOMS\System\File\Local\Directory;
+use phpOMS\Model\Message\FormValidation;
+use phpOMS\Message\Http\RequestStatusCode;
 
 /**
  * Exchange controller class.
@@ -89,6 +92,59 @@ final class ApiController extends Controller
         return false;
     }
 
+    /**
+     * Method to validate account creation from request
+     *
+     * @param RequestAbstract $request Request
+     *
+     * @return array<string, bool>
+     *
+     * @since 1.0.0
+     */
+    private function validateInterfaceInstall(RequestAbstract $request) : array
+    {
+        $val = [];
+        if (($val['interface'] = empty($request->getData('interface')))
+            || ($val['path'] = !\is_dir(__DIR__ . '/../Interfaces/' . $request->getData('interface')))
+        ) {
+            return $val;
+        }
+
+        return [];
+    }
+
+    /**
+     * Api method to install exchange interface
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiInterfaceInstall(RequestAbstract $request, ResponseAbstract $response, $data = null) : void
+    {
+        if (!empty($val = $this->validateInterfaceInstall($request))) {
+            $response->set('interface_install', new FormValidation($val));
+            $response->getHeader()->setStatusCode(RequestStatusCode::R_400);
+
+            return;
+        }
+
+        $interface = new InterfaceManager(
+            __DIR__ . '/../Interfaces/' . $request->getData('interface') . '/interface.json'
+        );
+        $interface->load();
+
+        InterfaceManagerMapper::create($interface);
+
+        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Interface', 'Interface successfully installed', $interface);
+    }
+
     /**
      * Api method to export data
      *
diff --git a/Interfaces/GSD/Importer.php b/Interfaces/GSD/Importer.php
index 7befa76..50fba94 100755
--- a/Interfaces/GSD/Importer.php
+++ b/Interfaces/GSD/Importer.php
@@ -100,9 +100,10 @@ final class Importer extends ImporterAbstract
             'database' => (string) ($request->getData('database') ?? ''),
             'login'    => (string) ($request->getData('login') ?? ''),
             'password' => (string) ($request->getData('password') ?? ''),
-            'prefix'   => '',
         ]);
 
+        $this->remote->connect();
+
         if ($this->remote->getStatus() !== DatabaseStatus::OK) {
             return false;
         }
@@ -152,8 +153,8 @@ final class Importer extends ImporterAbstract
     {
         DataMapperAbstract::setConnection($this->remote);
         $query = GSDCostCenterMapper::getQuery();
-        $query->where('row_create_time', '=>', $start->format('Y-m-d H:i:s'))
-            ->andWhere('row_create_time', '<=', $end->format('Y-m-d H:i:s'));
+        $query->where('FiKostenstellen_3.row_create_time', '>=', $start->format('Y-m-d H:i:s'))
+            ->andWhere('FiKostenstellen_3.row_create_time', '<=', $end->format('Y-m-d H:i:s'));
 
         $costCenters = GSDCostCenterMapper::getAllByQuery($query);
 
@@ -162,7 +163,7 @@ final class Importer extends ImporterAbstract
         foreach ($costCenters as $cc) {
             $obj = new CostCenter();
             $obj->setCode($cc->getCostCenter());
-            $obj->setName($cc->getDescription());
+            $obj->setName(\trim($cc->getDescription(), " ,\t"));
 
             CostCenterMapper::create($obj);
         }
@@ -182,8 +183,8 @@ final class Importer extends ImporterAbstract
     {
         DataMapperAbstract::setConnection($this->remote);
         $query = GSDCostObjectMapper::getQuery();
-        $query->where('row_create_time', '=>', $start->format('Y-m-d H:i:s'))
-            ->andWhere('row_create_time', '<=', $end->format('Y-m-d H:i:s'));
+        $query->where('FiKostentraeger_3.row_create_time', '>=', $start->format('Y-m-d H:i:s'))
+            ->andWhere('FiKostentraeger_3.row_create_time', '<=', $end->format('Y-m-d H:i:s'));
 
         $costObjects = GSDCostObjectMapper::getAllByQuery($query);
 
@@ -192,7 +193,7 @@ final class Importer extends ImporterAbstract
         foreach ($costObjects as $co) {
             $obj = new CostObject();
             $obj->setCode($co->getCostObject());
-            $obj->setName($co->getDescription());
+            $obj->setName(\trim($co->getDescription(), " ,\t"));
 
             CostObjectMapper::create($obj);
         }
@@ -212,8 +213,8 @@ final class Importer extends ImporterAbstract
     {
         DataMapperAbstract::setConnection($this->remote);
         $query = GSDCustomerMapper::getQuery();
-        $query->where('row_create_time', '=>', $start->format('Y-m-d H:i:s'))
-            ->andWhere('row_create_time', '<=', $end->format('Y-m-d H:i:s'));
+        $query->where('Kunden_3.row_create_time', '>=', $start->format('Y-m-d H:i:s'))
+            ->andWhere('Kunden_3.row_create_time', '<=', $end->format('Y-m-d H:i:s'));
 
         $customers = GSDCustomerMapper::getAllByQuery($query);
 
@@ -221,12 +222,12 @@ final class Importer extends ImporterAbstract
 
         foreach ($customers as $customer) {
             $obj = new Client();
-            $obj->setNumber($customer->getNumber());
+            $obj->setNumber(\trim($customer->getNumber()));
 
             $account = new Account();
-            $account->setName1($customer->getAddress()->getName1());
-            $account->setName2($customer->getAddress()->getName2());
-            $account->setName3($customer->getAddress()->getName3());
+            $account->setName1(\trim($customer->getAddress()->getName1(), " ,\t"));
+            $account->setName2(\trim($customer->getAddress()->getName2(), " ,\t"));
+            $account->setName3(\trim($customer->getAddress()->getName3(), " ,\t"));
 
             $profile = new Profile($account);
             $obj->setProfile($profile);
@@ -249,8 +250,8 @@ final class Importer extends ImporterAbstract
     {
         DataMapperAbstract::setConnection($this->remote);
         $query = GSDSupplierMapper::getQuery();
-        $query->where('row_create_time', '=>', $start->format('Y-m-d H:i:s'))
-            ->andWhere('row_create_time', '<=', $end->format('Y-m-d H:i:s'));
+        $query->where('Lieferanten_3.row_create_time', '>=', $start->format('Y-m-d H:i:s'))
+            ->andWhere('Lieferanten_3.row_create_time', '<=', $end->format('Y-m-d H:i:s'));
 
         $suppliers = GSDSupplierMapper::getAllByQuery($query);
 
@@ -261,9 +262,9 @@ final class Importer extends ImporterAbstract
             $obj->setNumber($supplier->getNumber());
 
             $account = new Account();
-            $account->setName1($supplier->getAddress()->getName1());
-            $account->setName2($supplier->getAddress()->getName2());
-            $account->setName3($supplier->getAddress()->getName3());
+            $account->setName1(\trim($supplier->getAddress()->getName1(), " ,\t"));
+            $account->setName2(\trim($supplier->getAddress()->getName2(), " ,\t"));
+            $account->setName3(\trim($supplier->getAddress()->getName3(), " ,\t"));
 
             $profile = new Profile($account);
             $obj->setProfile($profile);
@@ -300,8 +301,8 @@ final class Importer extends ImporterAbstract
     {
         DataMapperAbstract::setConnection($this->remote);
         $query = GSDArticleMapper::getQuery();
-        $query->where('row_create_time', '=>', $start->format('Y-m-d H:i:s'))
-            ->andWhere('row_create_time', '<=', $end->format('Y-m-d H:i:s'));
+        $query->where('Artikel_3.row_create_time', '>=', $start->format('Y-m-d H:i:s'))
+            ->andWhere('Artikel_3.row_create_time', '<=', $end->format('Y-m-d H:i:s'));
 
         $articles = GSDArticleMapper::getAllByQuery($query);
 
diff --git a/Interfaces/GSD/Model/GSDAddress.php b/Interfaces/GSD/Model/GSDAddress.php
index 4298839..caf0bcf 100755
--- a/Interfaces/GSD/Model/GSDAddress.php
+++ b/Interfaces/GSD/Model/GSDAddress.php
@@ -22,7 +22,7 @@ namespace Modules\Exchange\Interfaces\GSD\Model;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class GSDAddress
+class GSDAddress
 {
     /**
      * ID.
@@ -120,6 +120,32 @@ final class GSDAddress
      */
     private string $website = '';
 
+    /**
+     * Creator.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected int $createdBy = 0;
+
+    /**
+     * Created.
+     *
+     * @var \DateTimeImmutable
+     * @since 1.0.0
+     */
+    protected \DateTimeImmutable $createdAt;
+
+    /**
+     * Construct.
+     *
+     * @since 1.0.0
+     */
+    public function __construct()
+    {
+        $this->createdAt = new \DateTimeImmutable('now');
+    }
+
     /**
      * Get name1
      *
diff --git a/Interfaces/GSD/Model/GSDArticle.php b/Interfaces/GSD/Model/GSDArticle.php
index ec74fe3..4a72b76 100755
--- a/Interfaces/GSD/Model/GSDArticle.php
+++ b/Interfaces/GSD/Model/GSDArticle.php
@@ -22,7 +22,7 @@ namespace Modules\Exchange\Interfaces\GSD\Model;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class GSDArticle
+class GSDArticle
 {
     /**
      * ID.
@@ -33,12 +33,20 @@ final class GSDArticle
     protected int $id = 0;
 
     /**
-     * Create at.
+     * Creator.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected int $createdBy = 0;
+
+    /**
+     * Created.
      *
      * @var \DateTimeImmutable
      * @since 1.0.0
      */
-    private \DateTimeImmutable $createdAt;
+    protected \DateTimeImmutable $createdAt;
 
     /**
      * Article number.
diff --git a/Interfaces/GSD/Model/GSDCostCenter.php b/Interfaces/GSD/Model/GSDCostCenter.php
index e64d8d1..d70704d 100755
--- a/Interfaces/GSD/Model/GSDCostCenter.php
+++ b/Interfaces/GSD/Model/GSDCostCenter.php
@@ -22,7 +22,7 @@ namespace Modules\Exchange\Interfaces\GSD\Model;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class GSDCostCenter implements \JsonSerializable
+class GSDCostCenter implements \JsonSerializable
 {
     /**
      * ID.
diff --git a/Interfaces/GSD/Model/GSDCostCenterMapper.php b/Interfaces/GSD/Model/GSDCostCenterMapper.php
index 4c41134..97fba8c 100755
--- a/Interfaces/GSD/Model/GSDCostCenterMapper.php
+++ b/Interfaces/GSD/Model/GSDCostCenterMapper.php
@@ -36,7 +36,7 @@ final class GSDCostCenterMapper extends DataMapperAbstract
         'ROW_ID'          => ['name' => 'ROW_ID',          'type' => 'int',      'internal' => 'id'],
         'row_create_time' => ['name' => 'row_create_time', 'type' => 'DateTimeImmutable', 'internal' => 'createdAt', 'readonly' => true],
         'row_create_user' => ['name' => 'row_create_user', 'type' => 'int',      'internal' => 'createdBy', 'readonly' => true],
-        'KST'             => ['name' => 'KST',             'type' => 'string',   'internal' => 'costcenter'],
+        'KST'             => ['name' => 'KST',             'type' => 'string',   'internal' => 'costCenter'],
         'Bezeichnung'     => ['name' => 'Bezeichnung',     'type' => 'string',   'internal' => 'description'],
     ];
 
diff --git a/Interfaces/GSD/Model/GSDCostObject.php b/Interfaces/GSD/Model/GSDCostObject.php
index de36792..eb5852c 100755
--- a/Interfaces/GSD/Model/GSDCostObject.php
+++ b/Interfaces/GSD/Model/GSDCostObject.php
@@ -22,7 +22,7 @@ namespace Modules\Exchange\Interfaces\GSD\Model;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class GSDCostObject implements \JsonSerializable
+class GSDCostObject implements \JsonSerializable
 {
     /**
      * ID.
diff --git a/Interfaces/GSD/Model/GSDCostObjectMapper.php b/Interfaces/GSD/Model/GSDCostObjectMapper.php
index 8829e9c..d33e2d2 100755
--- a/Interfaces/GSD/Model/GSDCostObjectMapper.php
+++ b/Interfaces/GSD/Model/GSDCostObjectMapper.php
@@ -36,7 +36,7 @@ final class GSDCostObjectMapper extends DataMapperAbstract
         'ROW_ID'          => ['name' => 'ROW_ID',          'type' => 'int',      'internal' => 'id'],
         'row_create_time' => ['name' => 'row_create_time', 'type' => 'DateTimeImmutable', 'internal' => 'createdAt', 'readonly' => true],
         'row_create_user' => ['name' => 'row_create_user', 'type' => 'int',      'internal' => 'createdBy', 'readonly' => true],
-        'KTR'             => ['name' => 'KTR',             'type' => 'string',   'internal' => 'costobject'],
+        'KTR'             => ['name' => 'KTR',             'type' => 'string',   'internal' => 'costObject'],
         'Bezeichnung'     => ['name' => 'Bezeichnung',     'type' => 'string',   'internal' => 'description'],
     ];
 
diff --git a/Interfaces/GSD/Model/GSDCustomer.php b/Interfaces/GSD/Model/GSDCustomer.php
index eb343ef..6d67e68 100755
--- a/Interfaces/GSD/Model/GSDCustomer.php
+++ b/Interfaces/GSD/Model/GSDCustomer.php
@@ -22,7 +22,7 @@ namespace Modules\Exchange\Interfaces\GSD\Model;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class GSDCustomer
+class GSDCustomer
 {
     /**
      * ID.
@@ -38,7 +38,7 @@ final class GSDCustomer
      * @var int
      * @since 1.0.0
      */
-    protected $createdBy = 0;
+    protected int $createdBy = 0;
 
     /**
      * Created.
diff --git a/Interfaces/GSD/Model/GSDCustomerMapper.php b/Interfaces/GSD/Model/GSDCustomerMapper.php
index a841b0c..60d1e9f 100755
--- a/Interfaces/GSD/Model/GSDCustomerMapper.php
+++ b/Interfaces/GSD/Model/GSDCustomerMapper.php
@@ -39,18 +39,19 @@ final class GSDCustomerMapper extends DataMapperAbstract
         'Kundennummer'      => ['name' => 'Kundennummer',      'type' => 'string',   'internal' => 'number'],
         'Info'              => ['name' => 'Info',              'type' => 'string',   'internal' => 'info'],
         'Auftragssperre'    => ['name' => 'Auftragssperre',    'type' => 'string',   'internal' => 'deliveryStatus'],
-        'KreditLimitintern' => ['name' => 'KreditLimitintern', 'type' => 'string',   'internal' => 'creditlimit'],
+        'KreditLimitintern' => ['name' => 'KreditLimitintern', 'type' => 'float',    'internal' => 'creditlimit'],
         'EGUstId'           => ['name' => 'EGUstId',           'type' => 'string',   'internal' => 'egustid'],
         'Steuernummer'      => ['name' => 'Steuernummer',      'type' => 'string',   'internal' => 'taxid'],
         'BIC'               => ['name' => 'BIC',               'type' => 'string',   'internal' => 'bic'],
         'IBAN'              => ['name' => 'IBAN',              'type' => 'string',   'internal' => 'iban'],
-        'Verkaeufer'        => ['name' => 'Verkaeufer',        'type' => 'int',   'internal' => 'salesRep'],
+        'Verkaeufer'        => ['name' => 'Verkaeufer',        'type' => 'int',      'internal' => 'salesRep'],
+        'AdressId'        => ['name' => 'AdressId',        'type' => 'int',      'internal' => 'addr'],
     ];
 
     protected static array $ownsOne = [
         'addr' => [
             'mapper' => GSDAddressMapper::class,
-            'self'   => 'AddressId',
+            'self'   => 'AdressId',
         ],
     ];
 
diff --git a/Interfaces/GSD/Model/GSDSupplier.php b/Interfaces/GSD/Model/GSDSupplier.php
index 2237eb1..d3e6fb2 100755
--- a/Interfaces/GSD/Model/GSDSupplier.php
+++ b/Interfaces/GSD/Model/GSDSupplier.php
@@ -22,7 +22,7 @@ namespace Modules\Exchange\Interfaces\GSD\Model;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class GSDSupplier
+class GSDSupplier
 {
     /**
      * ID.
diff --git a/Interfaces/GSD/Model/GSDSupplierMapper.php b/Interfaces/GSD/Model/GSDSupplierMapper.php
index d989dce..93dc1cc 100755
--- a/Interfaces/GSD/Model/GSDSupplierMapper.php
+++ b/Interfaces/GSD/Model/GSDSupplierMapper.php
@@ -47,7 +47,7 @@ final class GSDSupplierMapper extends DataMapperAbstract
     protected static array $ownsOne = [
         'addr' => [
             'mapper' => GSDAddressMapper::class,
-            'self'   => 'AddressId',
+            'self'   => 'AdressId',
         ],
     ];
 
diff --git a/Interfaces/GSD/Model/NullGSDAddress.php b/Interfaces/GSD/Model/NullGSDAddress.php
new file mode 100644
index 0000000..f3177e6
--- /dev/null
+++ b/Interfaces/GSD/Model/NullGSDAddress.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   Modules\Exchange\Interfaces\GSD\Model
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\Exchange\Interfaces\GSD\Model;
+
+/**
+ * Null model.
+ *
+ * @package Modules\Exchange\Interfaces\GSD\Model
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullGSDAddress
+{
+}
diff --git a/Interfaces/GSD/Model/NullGSDArticle.php b/Interfaces/GSD/Model/NullGSDArticle.php
new file mode 100644
index 0000000..48d10cb
--- /dev/null
+++ b/Interfaces/GSD/Model/NullGSDArticle.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   Modules\Exchange\Interfaces\GSD\Model
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\Exchange\Interfaces\GSD\Model;
+
+/**
+ * Null model.
+ *
+ * @package Modules\Exchange\Interfaces\GSD\Model
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullGSDArticle
+{
+}
diff --git a/Interfaces/GSD/Model/NullGSDCostCenter.php b/Interfaces/GSD/Model/NullGSDCostCenter.php
new file mode 100644
index 0000000..9eeda3d
--- /dev/null
+++ b/Interfaces/GSD/Model/NullGSDCostCenter.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   Modules\Exchange\Interfaces\GSD\Model
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\Exchange\Interfaces\GSD\Model;
+
+/**
+ * Null model.
+ *
+ * @package Modules\Exchange\Interfaces\GSD\Model
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullGSDCostCenter
+{
+}
diff --git a/Interfaces/GSD/Model/NullGSDCostObject.php b/Interfaces/GSD/Model/NullGSDCostObject.php
new file mode 100644
index 0000000..f547384
--- /dev/null
+++ b/Interfaces/GSD/Model/NullGSDCostObject.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   Modules\Exchange\Interfaces\GSD\Model
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\Exchange\Interfaces\GSD\Model;
+
+/**
+ * Null model.
+ *
+ * @package Modules\Exchange\Interfaces\GSD\Model
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullGSDCostObject
+{
+}
diff --git a/Interfaces/GSD/Model/NullGSDCustomer.php b/Interfaces/GSD/Model/NullGSDCustomer.php
new file mode 100644
index 0000000..9a782e8
--- /dev/null
+++ b/Interfaces/GSD/Model/NullGSDCustomer.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   Modules\Exchange\Interfaces\GSD\Model
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\Exchange\Interfaces\GSD\Model;
+
+/**
+ * Null model.
+ *
+ * @package Modules\Exchange\Interfaces\GSD\Model
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullGSDCustomer
+{
+}
diff --git a/Interfaces/GSD/Model/NullGSDSupplier.php b/Interfaces/GSD/Model/NullGSDSupplier.php
new file mode 100644
index 0000000..548a6e9
--- /dev/null
+++ b/Interfaces/GSD/Model/NullGSDSupplier.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   Modules\Exchange\Interfaces\GSD\Model
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\Exchange\Interfaces\GSD\Model;
+
+/**
+ * Null model.
+ *
+ * @package Modules\Exchange\Interfaces\GSD\Model
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullGSDSupplier
+{
+}