diff --git a/Admin/Installer.php b/Admin/Installer.php
index 9c45928..1d1feb2 100755
--- a/Admin/Installer.php
+++ b/Admin/Installer.php
@@ -76,8 +76,8 @@ final class Installer extends InstallerAbstract
     {
         $contractTypes = [];
 
-        /** @var \Modules\ContractManagement\Controller\ApiController $module */
-        $module = $app->moduleManager->getModuleInstance('ContractManagement');
+        /** @var \Modules\ContractManagement\Controller\ApiContractTypeController $module */
+        $module = $app->moduleManager->getModuleInstance('ContractManagement', 'ApiContractType');
 
         foreach ($types as $type) {
             $response = new HttpResponse();
diff --git a/Admin/Routes/Web/Api.php b/Admin/Routes/Web/Api.php
index edd423e..7de80a1 100644
--- a/Admin/Routes/Web/Api.php
+++ b/Admin/Routes/Web/Api.php
@@ -20,7 +20,7 @@ use phpOMS\Router\RouteVerb;
 return [
     '^.*/contract/type.*$' => [
         [
-            'dest'       => '\Modules\ContractManagement\Controller\ApiController:apiContractTypeCreate',
+            'dest'       => '\Modules\ContractManagement\Controller\ApiContractTypeController:apiContractTypeCreate',
             'verb'       => RouteVerb::PUT,
             'permission' => [
                 'module' => Controller::NAME,
@@ -29,7 +29,7 @@ return [
             ],
         ],
         [
-            'dest'       => '\Modules\ContractManagement\Controller\ApiController:apiContractTypeUpdate',
+            'dest'       => '\Modules\ContractManagement\Controller\ApiContractTypeController:apiContractTypeUpdate',
             'verb'       => RouteVerb::SET,
             'permission' => [
                 'module' => Controller::NAME,
diff --git a/Controller/ApiAttributeController.php b/Controller/ApiAttributeController.php
index 336f7c4..8702767 100644
--- a/Controller/ApiAttributeController.php
+++ b/Controller/ApiAttributeController.php
@@ -17,20 +17,15 @@ namespace Modules\ContractManagement\Controller;
 use Modules\Attribute\Models\Attribute;
 use Modules\Attribute\Models\AttributeType;
 use Modules\Attribute\Models\AttributeValue;
-use Modules\Attribute\Models\NullAttributeType;
-use Modules\Attribute\Models\NullAttributeValue;
-use Modules\ContractManagement\Models\AttributeMapper;
-use Modules\ContractManagement\Models\AttributeTypeL11nMapper;
-use Modules\ContractManagement\Models\AttributeTypeMapper;
-use Modules\ContractManagement\Models\AttributeValueL11nMapper;
-use Modules\ContractManagement\Models\AttributeValueMapper;
+use Modules\ContractManagement\Models\Attribute\ContractAttributeMapper;
+use Modules\ContractManagement\Models\Attribute\ContractAttributeTypeL11nMapper;
+use Modules\ContractManagement\Models\Attribute\ContractAttributeTypeMapper;
+use Modules\ContractManagement\Models\Attribute\ContractAttributeValueL11nMapper;
+use Modules\ContractManagement\Models\Attribute\ContractAttributeValueMapper;
 use phpOMS\Localization\BaseStringL11n;
-use phpOMS\Localization\ISO639x1Enum;
 use phpOMS\Message\Http\RequestStatusCode;
-use phpOMS\Message\NotificationLevel;
 use phpOMS\Message\RequestAbstract;
 use phpOMS\Message\ResponseAbstract;
-use phpOMS\Model\Message\FormValidation;
 
 /**
  * ContractManagement class.
@@ -42,8 +37,10 @@ use phpOMS\Model\Message\FormValidation;
  */
 final class ApiAttributeController extends Controller
 {
+    use \Modules\Attribute\Controller\ApiAttributeTraitController;
+
     /**
-     * Api method to create contract attribute
+     * Api method to create item attribute
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
@@ -57,158 +54,16 @@ final class ApiAttributeController extends Controller
      */
     public function apiContractAttributeCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
     {
-        if (!empty($val = $this->validateContractAttributeCreate($request))) {
-            $response->data['attribute_create'] = new FormValidation($val);
-            $response->header->status           = RequestStatusCode::R_400;
+        if (!empty($val = $this->validateAttributeCreate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidCreateResponse($request, $response, $val);
 
             return;
         }
 
-        $attribute = $this->createContractAttributeFromRequest($request);
+        $attribute = $this->createAttributeFromRequest($request);
         $this->createModel($request->header->account, $attribute, ContractAttributeMapper::class, 'attribute', $request->getOrigin());
-
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Attribute', 'Attribute successfully created', $attribute);
-    }
-
-    /**
-     * Method to create contract attribute from request.
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return Attribute
-     *
-     * @since 1.0.0
-     */
-    private function createContractAttributeFromRequest(RequestAbstract $request) : Attribute
-    {
-        $attribute       = new Attribute();
-        $attribute->ref  = (int) $request->getData('contract');
-        $attribute->type = new NullAttributeType((int) $request->getData('type'));
-
-        if ($request->hasData('value')) {
-            $attribute->value = new NullAttributeValue((int) $request->getData('value'));
-        } else {
-            $newRequest = clone $request;
-            $newRequest->setData('value', $request->getData('custom'), true);
-
-            $value = $this->createAttributeValueFromRequest($newRequest);
-
-            $attribute->value = $value;
-        }
-
-        return $attribute;
-    }
-
-    /**
-     * Validate contract attribute create request
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return array<string, bool>
-     *
-     * @since 1.0.0
-     */
-    private function validateContractAttributeCreate(RequestAbstract $request) : array
-    {
-        $val = [];
-        if (($val['type'] = !$request->hasData('type'))
-            || ($val['value'] = (!$request->hasData('value') && !$request->hasData('custom')))
-            || ($val['contract'] = !$request->hasData('contract'))
-        ) {
-            return $val;
-        }
-
-        return [];
-    }
-
-    /**
-     * Api method to create contract attribute
-     *
-     * @param RequestAbstract  $request  Request
-     * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
-     *
-     * @return void
-     *
-     * @api
-     *
-     * @since 1.0.0
-     */
-    public function apiContractAttributeUpdate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
-    {
-        if (!empty($val = $this->validateContractAttributeUpdate($request))) {
-            $response->data['attribute_update'] = new FormValidation($val);
-            $response->header->status           = RequestStatusCode::R_400;
-
-            return;
-        }
-
-        $old = ContractAttributeMapper::get()
-            ->with('type')
-            ->with('type/defaults')
-            ->with('value')
-            ->where('id', (int) $request->getData('id'))
-            ->execute();
-
-        $new = $this->updateContractAttributeFromRequest($request, $old->deepClone());
-        $this->updateModel($request->header->account, $old, $new, ContractAttributeMapper::class, 'attribute', $request->getOrigin());
-
-        if ($new->value->getValue() !== $old->value->getValue()) {
-            $this->updateModel($request->header->account, $old->value, $new->value, ContractAttributeValueMapper::class, 'attribute_value', $request->getOrigin());
-        }
-
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Attribute', 'Attribute successfully updated', $new);
-    }
-
-    /**
-     * Method to create contract attribute from request.
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return Attribute
-     *
-     * @since 1.0.0
-     */
-    private function updateContractAttributeFromRequest(RequestAbstract $request, Attribute $attribute) : Attribute
-    {
-        if ($attribute->type->custom) {
-            if ($request->hasData('value')) {
-                // @question: we are overwriting the old value, could there be a use case where we want to create a new value and keep the old one?
-                $attribute->value->setValue($request->getData('value'), $attribute->type->datatype);
-            }
-        } else {
-            if ($request->hasData('value')) {
-                // @todo: fix by only accepting the value id to be used
-                // this is a workaround for now because the front end doesn't allow to dynamically show default values.
-                $value = $attribute->type->getDefaultByValue($request->getData('value'));
-
-                if ($value->id !== 0) {
-                    $attribute->value = $attribute->type->getDefaultByValue($request->getData('value'));
-                }
-            }
-        }
-
-        return $attribute;
-    }
-
-    /**
-     * Validate contract attribute create request
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return array<string, bool>
-     *
-     * @since 1.0.0
-     */
-    private function validateContractAttributeUpdate(RequestAbstract $request) : array
-    {
-        $val = [];
-        if (($val['id'] = !$request->hasData('id'))
-        ) {
-            return $val;
-        }
-
-        return [];
+        $this->createStandardCreateResponse($request, $response, $attribute);
     }
 
     /**
@@ -226,58 +81,16 @@ final class ApiAttributeController extends Controller
      */
     public function apiContractAttributeTypeL11nCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
     {
-        if (!empty($val = $this->validateContractAttributeTypeL11nCreate($request))) {
-            $response->data['attr_type_l11n_create'] = new FormValidation($val);
-            $response->header->status                = RequestStatusCode::R_400;
+        if (!empty($val = $this->validateAttributeTypeL11nCreate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidCreateResponse($request, $response, $val);
 
             return;
         }
 
-        $attrL11n = $this->createContractAttributeTypeL11nFromRequest($request);
+        $attrL11n = $this->createAttributeTypeL11nFromRequest($request);
         $this->createModel($request->header->account, $attrL11n, ContractAttributeTypeL11nMapper::class, 'attr_type_l11n', $request->getOrigin());
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Localization', 'Localization successfully created', $attrL11n);
-    }
-
-    /**
-     * Method to create contract attribute l11n from request.
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return BaseStringL11n
-     *
-     * @since 1.0.0
-     */
-    private function createContractAttributeTypeL11nFromRequest(RequestAbstract $request) : BaseStringL11n
-    {
-        $attrL11n      = new BaseStringL11n();
-        $attrL11n->ref = $request->getDataInt('type') ?? 0;
-        $attrL11n->setLanguage(
-            $request->getDataString('language') ?? $request->header->l11n->language
-        );
-        $attrL11n->content = $request->getDataString('title') ?? '';
-
-        return $attrL11n;
-    }
-
-    /**
-     * Validate contract attribute l11n create request
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return array<string, bool>
-     *
-     * @since 1.0.0
-     */
-    private function validateContractAttributeTypeL11nCreate(RequestAbstract $request) : array
-    {
-        $val = [];
-        if (($val['title'] = !$request->hasData('title'))
-            || ($val['type'] = !$request->hasData('type'))
-        ) {
-            return $val;
-        }
-
-        return [];
+        $this->createStandardCreateResponse($request, $response, $attrL11n);
     }
 
     /**
@@ -295,60 +108,16 @@ final class ApiAttributeController extends Controller
      */
     public function apiContractAttributeTypeCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
     {
-        if (!empty($val = $this->validateContractAttributeTypeCreate($request))) {
-            $response->data['attr_type_create'] = new FormValidation($val);
-            $response->header->status           = RequestStatusCode::R_400;
+        if (!empty($val = $this->validateAttributeTypeCreate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidCreateResponse($request, $response, $val);
 
             return;
         }
 
         $attrType = $this->createAttributeTypeFromRequest($request);
         $this->createModel($request->header->account, $attrType, ContractAttributeTypeMapper::class, 'attr_type', $request->getOrigin());
-
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Attribute type', 'Attribute type successfully created', $attrType);
-    }
-
-    /**
-     * Method to create contract attribute from request.
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return AttributeType
-     *
-     * @since 1.0.0
-     */
-    private function createAttributeTypeFromRequest(RequestAbstract $request) : AttributeType
-    {
-        $attrType                    = new AttributeType($request->getDataString('name') ?? '');
-        $attrType->datatype          = $request->getDataInt('datatype') ?? 0;
-        $attrType->custom            = $request->getDataBool('custom') ?? false;
-        $attrType->isRequired        = (bool) ($request->getData('is_required') ?? false);
-        $attrType->validationPattern = $request->getDataString('validation_pattern') ?? '';
-        $attrType->setL11n($request->getDataString('title') ?? '', $request->getDataString('language') ?? ISO639x1Enum::_EN);
-        $attrType->setFields($request->getDataInt('fields') ?? 0);
-
-        return $attrType;
-    }
-
-    /**
-     * Validate contract attribute create request
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return array<string, bool>
-     *
-     * @since 1.0.0
-     */
-    private function validateContractAttributeTypeCreate(RequestAbstract $request) : array
-    {
-        $val = [];
-        if (($val['title'] = !$request->hasData('title'))
-            || ($val['name'] = !$request->hasData('name'))
-        ) {
-            return $val;
-        }
-
-        return [];
+        $this->createStandardCreateResponse($request, $response, $attrType);
     }
 
     /**
@@ -366,14 +135,19 @@ final class ApiAttributeController extends Controller
      */
     public function apiContractAttributeValueCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
     {
-        if (!empty($val = $this->validateContractAttributeValueCreate($request))) {
-            $response->data['attr_value_create'] = new FormValidation($val);
-            $response->header->status            = RequestStatusCode::R_400;
+        if (!empty($val = $this->validateAttributeValueCreate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidCreateResponse($request, $response, $val);
 
             return;
         }
 
-        $attrValue = $this->createAttributeValueFromRequest($request);
+        /** @var \Modules\Attribute\Models\AttributeType $type */
+        $type = ContractAttributeTypeMapper::get()
+            ->where('id', $request->getDataInt('type') ?? 0)
+            ->execute();
+
+        $attrValue = $this->createAttributeValueFromRequest($request, $type);
         $this->createModel($request->header->account, $attrValue, ContractAttributeValueMapper::class, 'attr_value', $request->getOrigin());
 
         if ($attrValue->isDefault) {
@@ -385,55 +159,7 @@ final class ApiAttributeController extends Controller
             );
         }
 
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Attribute value', 'Attribute value successfully created', $attrValue);
-    }
-
-    /**
-     * Method to create contract attribute value from request.
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return AttributeValue
-     *
-     * @since 1.0.0
-     */
-    private function createAttributeValueFromRequest(RequestAbstract $request) : AttributeValue
-    {
-        /** @var AttributeType $type */
-        $type = ContractAttributeTypeMapper::get()
-            ->where('id', $request->getDataInt('type') ?? 0)
-            ->execute();
-
-        $attrValue            = new AttributeValue();
-        $attrValue->isDefault = $request->getDataBool('default') ?? false;
-        $attrValue->setValue($request->getData('value'), $type->datatype);
-
-        if ($request->hasData('title')) {
-            $attrValue->setL11n($request->getDataString('title') ?? '', $request->getDataString('language') ?? ISO639x1Enum::_EN);
-        }
-
-        return $attrValue;
-    }
-
-    /**
-     * Validate contract attribute value create request
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return array<string, bool>
-     *
-     * @since 1.0.0
-     */
-    private function validateContractAttributeValueCreate(RequestAbstract $request) : array
-    {
-        $val = [];
-        if (($val['type'] = !$request->hasData('type'))
-            || ($val['value'] = !$request->hasData('value'))
-        ) {
-            return $val;
-        }
-
-        return [];
+        $this->createStandardCreateResponse($request, $response, $attrValue);
     }
 
     /**
@@ -451,62 +177,20 @@ final class ApiAttributeController extends Controller
      */
     public function apiContractAttributeValueL11nCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
     {
-        if (!empty($val = $this->validateContractAttributeValueL11nCreate($request))) {
-            $response->data['attr_value_l11n_create'] = new FormValidation($val);
-            $response->header->status                 = RequestStatusCode::R_400;
+        if (!empty($val = $this->validateAttributeValueL11nCreate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidCreateResponse($request, $response, $val);
 
             return;
         }
 
         $attrL11n = $this->createAttributeValueL11nFromRequest($request);
         $this->createModel($request->header->account, $attrL11n, ContractAttributeValueL11nMapper::class, 'attr_value_l11n', $request->getOrigin());
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Localization', 'Localization successfully created', $attrL11n);
+        $this->createStandardCreateResponse($request, $response, $attrL11n);
     }
 
     /**
-     * Method to create contract attribute l11n from request.
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return BaseStringL11n
-     *
-     * @since 1.0.0
-     */
-    private function createAttributeValueL11nFromRequest(RequestAbstract $request) : BaseStringL11n
-    {
-        $attrL11n      = new BaseStringL11n();
-        $attrL11n->ref = $request->getDataInt('value') ?? 0;
-        $attrL11n->setLanguage(
-            $request->getDataString('language') ?? $request->header->l11n->language
-        );
-        $attrL11n->content = $request->getDataString('title') ?? '';
-
-        return $attrL11n;
-    }
-
-    /**
-     * Validate contract attribute l11n create request
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return array<string, bool>
-     *
-     * @since 1.0.0
-     */
-    private function validateContractAttributeValueL11nCreate(RequestAbstract $request) : array
-    {
-        $val = [];
-        if (($val['title'] = !$request->hasData('title'))
-            || ($val['value'] = !$request->hasData('value'))
-        ) {
-            return $val;
-        }
-
-        return [];
-    }
-
-    /**
-     * Api method to handle api contract attributes
+     * Api method to update ContractAttribute
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
@@ -518,17 +202,322 @@ final class ApiAttributeController extends Controller
      *
      * @since 1.0.0
      */
-    public function apiContractAttribute(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    public function apiContractAttributeUpdate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
     {
-        if (!empty($val = $this->validateContractAttributeValueL11nCreate($request))) {
-            $response->data['attr_value_l11n_create'] = new FormValidation($val);
-            $response->header->status                 = RequestStatusCode::R_400;
+        if (!empty($val = $this->validateAttributeUpdate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidUpdateResponse($request, $response, $val);
 
             return;
         }
 
-        $attrL11n = $this->createAttributeValueL11nFromRequest($request);
-        $this->createModel($request->header->account, $attrL11n, ContractAttributeValueL11nMapper::class, 'attr_value_l11n', $request->getOrigin());
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Localization', 'Localization successfully created', $attrL11n);
+        /** @var Attribute $old */
+        $old = ContractAttributeMapper::get()
+            ->with('type')
+            ->with('type/defaults')
+            ->with('value')
+            ->where('id', (int) $request->getData('id'))
+            ->execute();
+
+        $new = $this->updateAttributeFromRequest($request, clone $old);
+
+        if ($new->id === 0) {
+            // Set response header to invalid request because of invalid data
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidUpdateResponse($request, $response, $new);
+
+            return;
+        }
+
+        $this->updateModel($request->header->account, $old, $new, ContractAttributeMapper::class, 'contract_attribute', $request->getOrigin());
+
+        if ($new->value->getValue() !== $old->value->getValue()) {
+            $this->updateModel($request->header->account, $old->value, $new->value, ContractAttributeValueMapper::class, 'attribute_value', $request->getOrigin());
+        }
+
+        $this->createStandardUpdateResponse($request, $response, $new);
+    }
+
+    /**
+     * Api method to delete ContractAttribute
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractAttributeDelete(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateAttributeDelete($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidDeleteResponse($request, $response, $val);
+
+            return;
+        }
+
+        $contractAttribute = ContractAttributeMapper::get()
+            ->with('type')
+            ->where('id', (int) $request->getData('id'))
+            ->execute();
+
+        if ($contractAttribute->type->isRequired) {
+            $this->createInvalidDeleteResponse($request, $response, []);
+
+            return;
+        }
+
+        $this->deleteModel($request->header->account, $contractAttribute, ContractAttributeMapper::class, 'contract_attribute', $request->getOrigin());
+        $this->createStandardDeleteResponse($request, $response, $contractAttribute);
+    }
+
+    /**
+     * Api method to update ContractAttributeTypeL11n
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractAttributeTypeL11nUpdate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateAttributeTypeL11nUpdate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidUpdateResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var BaseStringL11n $old */
+        $old = ContractAttributeTypeL11nMapper::get()->where('id', (int) $request->getData('id'))->execute();
+        $new = $this->updateAttributeTypeL11nFromRequest($request, clone $old);
+
+        $this->updateModel($request->header->account, $old, $new, ContractAttributeTypeL11nMapper::class, 'contract_attribute_type_l11n', $request->getOrigin());
+        $this->createStandardUpdateResponse($request, $response, $new);
+    }
+
+    /**
+     * Api method to delete ContractAttributeTypeL11n
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractAttributeTypeL11nDelete(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateAttributeTypeL11nDelete($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidDeleteResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var \Modules\ContractManagement\Models\ContractAttributeTypeL11n $contractAttributeTypeL11n */
+        $contractAttributeTypeL11n = ContractAttributeTypeL11nMapper::get()->where('id', (int) $request->getData('id'))->execute();
+        $this->deleteModel($request->header->account, $contractAttributeTypeL11n, ContractAttributeTypeL11nMapper::class, 'contract_attribute_type_l11n', $request->getOrigin());
+        $this->createStandardDeleteResponse($request, $response, $contractAttributeTypeL11n);
+    }
+
+    /**
+     * Api method to update ContractAttributeType
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractAttributeTypeUpdate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateAttributeTypeUpdate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidUpdateResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var AttributeType $old */
+        $old = ContractAttributeTypeMapper::get()->where('id', (int) $request->getData('id'))->execute();
+        $new = $this->updateAttributeTypeFromRequest($request, clone $old);
+
+        $this->updateModel($request->header->account, $old, $new, ContractAttributeTypeMapper::class, 'contract_attribute_type', $request->getOrigin());
+        $this->createStandardUpdateResponse($request, $response, $new);
+    }
+
+    /**
+     * Api method to delete ContractAttributeType
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @todo: implement
+     *
+     * @since 1.0.0
+     */
+    public function apiContractAttributeTypeDelete(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateAttributeTypeDelete($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidDeleteResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var \Modules\ContractManagement\Models\ContractAttributeType $contractAttributeType */
+        $contractAttributeType = ContractAttributeTypeMapper::get()->where('id', (int) $request->getData('id'))->execute();
+        $this->deleteModel($request->header->account, $contractAttributeType, ContractAttributeTypeMapper::class, 'contract_attribute_type', $request->getOrigin());
+        $this->createStandardDeleteResponse($request, $response, $contractAttributeType);
+    }
+
+    /**
+     * Api method to update ContractAttributeValue
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractAttributeValueUpdate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateAttributeValueUpdate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidUpdateResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var AttributeValue $old */
+        $old = ContractAttributeValueMapper::get()->where('id', (int) $request->getData('id'))->execute();
+
+        /** @var \Modules\Attribute\Models\Attribute $type */
+        $attr = ContractAttributeMapper::get()
+            ->with('type')
+            ->where('id', $request->getDataInt('attribute') ?? 0)
+            ->execute();
+
+        $new = $this->updateAttributeValueFromRequest($request, clone $old, $attr);
+
+        $this->updateModel($request->header->account, $old, $new, ContractAttributeValueMapper::class, 'contract_attribute_value', $request->getOrigin());
+        $this->createStandardUpdateResponse($request, $response, $new);
+    }
+
+    /**
+     * Api method to delete ContractAttributeValue
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractAttributeValueDelete(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        return;
+
+        // @todo: I don't think values can be deleted? Only Attributes
+        // However, It should be possible to remove UNUSED default values
+        // either here or other function?
+        if (!empty($val = $this->validateAttributeValueDelete($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidDeleteResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var \Modules\ContractManagement\Models\ContractAttributeValue $contractAttributeValue */
+        $contractAttributeValue = ContractAttributeValueMapper::get()->where('id', (int) $request->getData('id'))->execute();
+        $this->deleteModel($request->header->account, $contractAttributeValue, ContractAttributeValueMapper::class, 'contract_attribute_value', $request->getOrigin());
+        $this->createStandardDeleteResponse($request, $response, $contractAttributeValue);
+    }
+
+    /**
+     * Api method to update ContractAttributeValueL11n
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractAttributeValueL11nUpdate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateAttributeValueL11nUpdate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidUpdateResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var BaseStringL11n $old */
+        $old = ContractAttributeValueL11nMapper::get()->where('id', (int) $request->getData('id'));
+        $new = $this->updateAttributeValueL11nFromRequest($request, clone $old);
+
+        $this->updateModel($request->header->account, $old, $new, ContractAttributeValueL11nMapper::class, 'contract_attribute_value_l11n', $request->getOrigin());
+        $this->createStandardUpdateResponse($request, $response, $new);
+    }
+
+    /**
+     * Api method to delete ContractAttributeValueL11n
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractAttributeValueL11nDelete(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateAttributeValueL11nDelete($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidDeleteResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var \Modules\ContractManagement\Models\ContractAttributeValueL11n $contractAttributeValueL11n */
+        $contractAttributeValueL11n = ContractAttributeValueL11nMapper::get()->where('id', (int) $request->getData('id'))->execute();
+        $this->deleteModel($request->header->account, $contractAttributeValueL11n, ContractAttributeValueL11nMapper::class, 'contract_attribute_value_l11n', $request->getOrigin());
+        $this->createStandardDeleteResponse($request, $response, $contractAttributeValueL11n);
     }
 }
diff --git a/Controller/ApiContractTypeController.php b/Controller/ApiContractTypeController.php
new file mode 100644
index 0000000..da37aeb
--- /dev/null
+++ b/Controller/ApiContractTypeController.php
@@ -0,0 +1,404 @@
+<?php
+
+/**
+ * Jingga
+ *
+ * PHP Version 8.1
+ *
+ * @package   Modules\ContractManagement
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 2.0
+ * @version   1.0.0
+ * @link      https://jingga.app
+ */
+
+declare(strict_types=1);
+
+namespace Modules\ContractManagement\Controller;
+
+use Modules\ContractManagement\Models\ContractTypeL11nMapper;
+use Modules\ContractManagement\Models\ContractTypeMapper;
+use phpOMS\Localization\BaseStringL11n;
+use phpOMS\Localization\BaseStringL11nType;
+use phpOMS\Localization\ISO639x1Enum;
+use phpOMS\Message\Http\RequestStatusCode;
+use phpOMS\Message\RequestAbstract;
+use phpOMS\Message\ResponseAbstract;
+
+/**
+ * ContractManagement class.
+ *
+ * @package Modules\ContractManagement
+ * @license OMS License 2.0
+ * @link    https://jingga.app
+ * @since   1.0.0
+ */
+final class ApiContractTypeController extends Controller
+{
+    /**
+     * Api method to create item attribute type
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractTypeCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateContractTypeCreate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidCreateResponse($request, $response, $val);
+
+            return;
+        }
+
+        $contractType = $this->createContractTypeFromRequest($request);
+        $this->createModel($request->header->account, $contractType, ContractTypeMapper::class, 'contract_type', $request->getOrigin());
+        $this->createStandardCreateResponse($request, $response, $contractType);
+    }
+
+    /**
+     * Method to create item attribute from request.
+     *
+     * @param RequestAbstract $request Request
+     *
+     * @return BaseStringL11nType
+     *
+     * @since 1.0.0
+     */
+    private function createContractTypeFromRequest(RequestAbstract $request) : BaseStringL11nType
+    {
+        $contractType = new BaseStringL11nType();
+        $contractType->setL11n($request->getDataString('title') ?? '', $request->getDataString('language') ?? ISO639x1Enum::_EN);
+        $contractType->title = $request->getDataString('name') ?? '';
+
+        return $contractType;
+    }
+
+    /**
+     * Validate item attribute create request
+     *
+     * @param RequestAbstract $request Request
+     *
+     * @return array<string, bool>
+     *
+     * @since 1.0.0
+     */
+    private function validateContractTypeCreate(RequestAbstract $request) : array
+    {
+        $val = [];
+        if (($val['title'] = !$request->hasData('title'))
+        ) {
+            return $val;
+        }
+
+        return [];
+    }
+
+    /**
+     * Api method to create item attribute l11n
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractTypeL11nCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateContractTypeL11nCreate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidCreateResponse($request, $response, $val);
+
+            return;
+        }
+
+        $contractTypeL11n = $this->createContractTypeL11nFromRequest($request);
+        $this->createModel($request->header->account, $contractTypeL11n, ContractTypeL11nMapper::class, 'contract_type_l11n', $request->getOrigin());
+        $this->createStandardCreateResponse($request, $response, $contractTypeL11n);
+    }
+
+    /**
+     * Method to create item attribute l11n from request.
+     *
+     * @param RequestAbstract $request Request
+     *
+     * @return BaseStringL11n
+     *
+     * @since 1.0.0
+     */
+    private function createContractTypeL11nFromRequest(RequestAbstract $request) : BaseStringL11n
+    {
+        $contractTypeL11n      = new BaseStringL11n();
+        $contractTypeL11n->ref = $request->getDataInt('type') ?? 0;
+        $contractTypeL11n->setLanguage(
+            $request->getDataString('language') ?? $request->header->l11n->language
+        );
+        $contractTypeL11n->content = $request->getDataString('title') ?? '';
+
+        return $contractTypeL11n;
+    }
+
+    /**
+     * Validate item attribute l11n create request
+     *
+     * @param RequestAbstract $request Request
+     *
+     * @return array<string, bool>
+     *
+     * @since 1.0.0
+     */
+    private function validateContractTypeL11nCreate(RequestAbstract $request) : array
+    {
+        $val = [];
+        if (($val['title'] = !$request->hasData('title'))
+            || ($val['type'] = !$request->hasData('type'))
+        ) {
+            return $val;
+        }
+
+        return [];
+    }
+
+    /**
+     * Api method to update ContractType
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractTypeUpdate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateContractTypeUpdate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidUpdateResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var BaseStringL11nType $old */
+        $old = ContractTypeMapper::get()->where('id', (int) $request->getData('id'));
+        $new = $this->updateContractTypeFromRequest($request, clone $old);
+
+        $this->updateModel($request->header->account, $old, $new, ContractTypeMapper::class, 'contract_type', $request->getOrigin());
+        $this->createStandardUpdateResponse($request, $response, $new);
+    }
+
+    /**
+     * Method to update ContractType from request.
+     *
+     * @param RequestAbstract  $request Request
+     * @param BaseStringL11nType     $new     Model to modify
+     *
+     * @return BaseStringL11nType
+     *
+     * @todo: implement
+     *
+     * @since 1.0.0
+     */
+    public function updateContractTypeFromRequest(RequestAbstract $request, BaseStringL11nType $new) : BaseStringL11nType
+    {
+        $new->title = $request->getDataString('name') ?? $new->title;
+
+        return $new;
+    }
+
+    /**
+     * Validate ContractType update request
+     *
+     * @param RequestAbstract $request Request
+     *
+     * @return array<string, bool>
+     *
+     * @todo: implement
+     *
+     * @since 1.0.0
+     */
+    private function validateContractTypeUpdate(RequestAbstract $request) : array
+    {
+        $val = [];
+        if (($val['id'] = !$request->hasData('id'))) {
+            return $val;
+        }
+
+        return [];
+    }
+
+    /**
+     * Api method to delete ContractType
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractTypeDelete(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateContractTypeDelete($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidDeleteResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var \Modules\ContractManagement\Models\ContractType $contractType */
+        $contractType = ContractTypeMapper::get()->where('id', (int) $request->getData('id'))->execute();
+        $this->deleteModel($request->header->account, $contractType, ContractTypeMapper::class, 'contract_type', $request->getOrigin());
+        $this->createStandardDeleteResponse($request, $response, $contractType);
+    }
+
+    /**
+     * Validate ContractType delete request
+     *
+     * @param RequestAbstract $request Request
+     *
+     * @return array<string, bool>
+     *
+     * @since 1.0.0
+     */
+    private function validateContractTypeDelete(RequestAbstract $request) : array
+    {
+        $val = [];
+        if (($val['id'] = !$request->hasData('id'))) {
+            return $val;
+        }
+
+        return [];
+    }
+
+    /**
+     * Api method to update ContractTypeL11n
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractTypeL11nUpdate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateContractTypeL11nUpdate($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidUpdateResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var BaseStringL11n $old */
+        $old = ContractTypeL11nMapper::get()->where('id', (int) $request->getData('id'));
+        $new = $this->updateContractTypeL11nFromRequest($request, clone $old);
+
+        $this->updateModel($request->header->account, $old, $new, ContractTypeL11nMapper::class, 'contract_type_l11n', $request->getOrigin());
+        $this->createStandardUpdateResponse($request, $response, $new);
+    }
+
+    /**
+     * Method to update ContractTypeL11n from request.
+     *
+     * @param RequestAbstract  $request Request
+     * @param BaseStringL11n     $new     Model to modify
+     *
+     * @return BaseStringL11n
+     *
+     * @since 1.0.0
+     */
+    public function updateContractTypeL11nFromRequest(RequestAbstract $request, BaseStringL11n $new) : BaseStringL11n
+    {
+        $new->setLanguage(
+            $request->getDataString('language') ?? $new->language
+        );
+        $new->content = $request->getDataString('title') ?? $new->content;
+
+        return $new;
+    }
+
+    /**
+     * Validate ContractTypeL11n update request
+     *
+     * @param RequestAbstract $request Request
+     *
+     * @return array<string, bool>
+     *
+     * @since 1.0.0
+     */
+    private function validateContractTypeL11nUpdate(RequestAbstract $request) : array
+    {
+        $val = [];
+        if (($val['id'] = !$request->hasData('id'))) {
+            return $val;
+        }
+
+        return [];
+    }
+
+    /**
+     * Api method to delete ContractTypeL11n
+     *
+     * @param RequestAbstract  $request  Request
+     * @param ResponseAbstract $response Response
+     * @param mixed            $data     Generic data
+     *
+     * @return void
+     *
+     * @api
+     *
+     * @since 1.0.0
+     */
+    public function apiContractTypeL11nDelete(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    {
+        if (!empty($val = $this->validateContractTypeL11nDelete($request))) {
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidDeleteResponse($request, $response, $val);
+
+            return;
+        }
+
+        /** @var \Modules\ContractManagement\Models\ContractTypeL11n $contractTypeL11n */
+        $contractTypeL11n = ContractTypeL11nMapper::get()->where('id', (int) $request->getData('id'))->execute();
+        $this->deleteModel($request->header->account, $contractTypeL11n, ContractTypeL11nMapper::class, 'contract_type_l11n', $request->getOrigin());
+        $this->createStandardDeleteResponse($request, $response, $contractTypeL11n);
+    }
+
+    /**
+     * Validate ContractTypeL11n delete request
+     *
+     * @param RequestAbstract $request Request
+     *
+     * @return array<string, bool>
+     *
+     * @since 1.0.0
+     */
+    private function validateContractTypeL11nDelete(RequestAbstract $request) : array
+    {
+        $val = [];
+        if (($val['id'] = !$request->hasData('id'))) {
+            return $val;
+        }
+
+        return [];
+    }
+}
diff --git a/Controller/ApiController.php b/Controller/ApiController.php
index e887b46..2d2954b 100755
--- a/Controller/ApiController.php
+++ b/Controller/ApiController.php
@@ -17,20 +17,13 @@ namespace Modules\ContractManagement\Controller;
 use Modules\Admin\Models\NullAccount;
 use Modules\ContractManagement\Models\Contract;
 use Modules\ContractManagement\Models\ContractMapper;
-use Modules\ContractManagement\Models\ContractTypeL11nMapper;
-use Modules\ContractManagement\Models\ContractTypeMapper;
 use Modules\Media\Models\MediaMapper;
 use Modules\Media\Models\PathSettings;
 use Modules\Organization\Models\NullUnit;
-use phpOMS\Localization\BaseStringL11n;
-use phpOMS\Localization\BaseStringL11nType;
-use phpOMS\Localization\ISO639x1Enum;
 use phpOMS\Localization\NullBaseStringL11nType;
 use phpOMS\Message\Http\RequestStatusCode;
-use phpOMS\Message\NotificationLevel;
 use phpOMS\Message\RequestAbstract;
 use phpOMS\Message\ResponseAbstract;
-use phpOMS\Model\Message\FormValidation;
 
 /**
  * Api controller for the contracts module.
@@ -58,15 +51,15 @@ final class ApiController extends Controller
     public function apiContractCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
     {
         if (!empty($val = $this->validateContractCreate($request))) {
-            $response->data['contract_create'] = new FormValidation($val);
-            $response->header->status          = RequestStatusCode::R_400;
+            $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidCreateResponse($request, $response, $val);
 
             return;
         }
 
         $contract = $this->createContractFromRequest($request);
         $this->createModel($request->header->account, $contract, ContractMapper::class, 'contract', $request->getOrigin());
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Contract', 'Contract successfully created', $contract);
+        $this->createStandardCreateResponse($request, $response, $contract);
     }
 
     /**
@@ -150,8 +143,8 @@ final class ApiController extends Controller
         $uploadedFiles = $request->files;
 
         if (empty($uploadedFiles)) {
-            $this->fillJsonResponse($request, $response, NotificationLevel::ERROR, 'Contract', 'Invalid contract image', $uploadedFiles);
             $response->header->status = RequestStatusCode::R_400;
+            $this->createInvalidCreateResponse($request, $response, $uploadedFiles);
 
             return;
         }
@@ -195,141 +188,6 @@ final class ApiController extends Controller
             ContractMapper::class, 'files', '', $request->getOrigin()
         );
 
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Image', 'Image successfully updated', $uploaded);
-    }
-
-    /**
-     * Api method to create item attribute type
-     *
-     * @param RequestAbstract  $request  Request
-     * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
-     *
-     * @return void
-     *
-     * @api
-     *
-     * @since 1.0.0
-     */
-    public function apiContractTypeCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
-    {
-        if (!empty($val = $this->validateContractTypeCreate($request))) {
-            $response->data['contract_type_create'] = new FormValidation($val);
-            $response->header->status               = RequestStatusCode::R_400;
-
-            return;
-        }
-
-        $contractType = $this->createContractTypeFromRequest($request);
-        $this->createModel($request->header->account, $contractType, ContractTypeMapper::class, 'contract_type', $request->getOrigin());
-
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Contract type', 'Contract type successfully created', $contractType);
-    }
-
-    /**
-     * Method to create item attribute from request.
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return BaseStringL11nType
-     *
-     * @since 1.0.0
-     */
-    private function createContractTypeFromRequest(RequestAbstract $request) : BaseStringL11nType
-    {
-        $contractType = new BaseStringL11nType();
-        $contractType->setL11n($request->getDataString('title') ?? '', $request->getDataString('language') ?? ISO639x1Enum::_EN);
-        $contractType->title = $request->getDataString('name') ?? '';
-
-        return $contractType;
-    }
-
-    /**
-     * Validate item attribute create request
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return array<string, bool>
-     *
-     * @since 1.0.0
-     */
-    private function validateContractTypeCreate(RequestAbstract $request) : array
-    {
-        $val = [];
-        if (($val['title'] = !$request->hasData('title'))
-        ) {
-            return $val;
-        }
-
-        return [];
-    }
-
-    /**
-     * Api method to create item l11n type
-     *
-     * @param RequestAbstract  $request  Request
-     * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
-     *
-     * @return void
-     *
-     * @api
-     *
-     * @since 1.0.0
-     */
-    public function apiContractTypeL11nCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
-    {
-        if (!empty($val = $this->validateContractTypeL11nCreate($request))) {
-            $response->data['contract_type_create'] = new FormValidation($val);
-            $response->header->status               = RequestStatusCode::R_400;
-
-            return;
-        }
-
-        $itemL11nType = $this->createContractTypeL11nFromRequest($request);
-        $this->createModel($request->header->account, $itemL11nType, ContractTypeL11nMapper::class, 'contract_type', $request->getOrigin());
-        $this->fillJsonResponse($request, $response, NotificationLevel::OK, 'Contract type', 'Contract localization type successfully created', $itemL11nType);
-    }
-
-    /**
-     * Method to create item l11n type from request.
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return BaseStringL11n
-     *
-     * @since 1.0.0
-     */
-    private function createContractTypeL11nFromRequest(RequestAbstract $request) : BaseStringL11n
-    {
-        $typeL11n          = new BaseStringL11n();
-        $typeL11n->ref     = $request->getDataInt('type') ?? 0;
-        $typeL11n->content = $request->getDataString('title') ?? '';
-        $typeL11n->setLanguage(
-            $request->getDataString('language') ?? $request->header->l11n->language
-        );
-
-        return $typeL11n;
-    }
-
-    /**
-     * Validate item l11n type create request
-     *
-     * @param RequestAbstract $request Request
-     *
-     * @return array<string, bool>
-     *
-     * @since 1.0.0
-     */
-    private function validateContractTypeL11nCreate(RequestAbstract $request) : array
-    {
-        $val = [];
-        if (($val['title'] = !$request->hasData('title'))
-            || ($val['type'] = !$request->hasData('type'))
-        ) {
-            return $val;
-        }
-
-        return [];
+        $this->createStandardUpdateResponse($request, $response, $uploaded);
     }
 }
diff --git a/Models/ContractAttributeMapper.php b/Models/Attribute/ContractAttributeMapper.php
similarity index 93%
rename from Models/ContractAttributeMapper.php
rename to Models/Attribute/ContractAttributeMapper.php
index 9a1e5b1..5820081 100644
--- a/Models/ContractAttributeMapper.php
+++ b/Models/Attribute/ContractAttributeMapper.php
@@ -4,7 +4,7 @@
  *
  * PHP Version 8.1
  *
- * @package   Modules\ContractManagement\Models
+ * @package   Modules\ContractManagement\Models\Attribute
  * @copyright Dennis Eichhorn
  * @license   OMS License 2.0
  * @version   1.0.0
@@ -12,7 +12,7 @@
  */
 declare(strict_types=1);
 
-namespace Modules\ContractManagement\Models;
+namespace Modules\ContractManagement\Models\Attribute;
 
 use Modules\Attribute\Models\Attribute;
 use phpOMS\DataStorage\Database\Mapper\DataMapperFactory;
@@ -20,7 +20,7 @@ use phpOMS\DataStorage\Database\Mapper\DataMapperFactory;
 /**
  * Fleet mapper class.
  *
- * @package Modules\ContractManagement\Models
+ * @package Modules\ContractManagement\Models\Attribute
  * @license OMS License 2.0
  * @link    https://jingga.app
  * @since   1.0.0
diff --git a/Models/ContractAttributeTypeL11nMapper.php b/Models/Attribute/ContractAttributeTypeL11nMapper.php
similarity index 91%
rename from Models/ContractAttributeTypeL11nMapper.php
rename to Models/Attribute/ContractAttributeTypeL11nMapper.php
index bb3528e..f1d8b77 100644
--- a/Models/ContractAttributeTypeL11nMapper.php
+++ b/Models/Attribute/ContractAttributeTypeL11nMapper.php
@@ -4,7 +4,7 @@
  *
  * PHP Version 8.1
  *
- * @package   Modules\ContractManagement\Models
+ * @package   Modules\ContractManagement\Models\Attribute
  * @copyright Dennis Eichhorn
  * @license   OMS License 2.0
  * @version   1.0.0
@@ -12,7 +12,7 @@
  */
 declare(strict_types=1);
 
-namespace Modules\ContractManagement\Models;
+namespace Modules\ContractManagement\Models\Attribute;
 
 use phpOMS\DataStorage\Database\Mapper\DataMapperFactory;
 use phpOMS\Localization\BaseStringL11n;
@@ -20,7 +20,7 @@ use phpOMS\Localization\BaseStringL11n;
 /**
  * Contract mapper class.
  *
- * @package Modules\ContractManagement\Models
+ * @package Modules\ContractManagement\Models\Attribute
  * @license OMS License 2.0
  * @link    https://jingga.app
  * @since   1.0.0
diff --git a/Models/ContractAttributeTypeMapper.php b/Models/Attribute/ContractAttributeTypeMapper.php
similarity index 94%
rename from Models/ContractAttributeTypeMapper.php
rename to Models/Attribute/ContractAttributeTypeMapper.php
index 87b6c34..3b3e678 100644
--- a/Models/ContractAttributeTypeMapper.php
+++ b/Models/Attribute/ContractAttributeTypeMapper.php
@@ -4,7 +4,7 @@
  *
  * PHP Version 8.1
  *
- * @package   Modules\ContractManagement\Models
+ * @package   Modules\ContractManagement\Models\Attribute
  * @copyright Dennis Eichhorn
  * @license   OMS License 2.0
  * @version   1.0.0
@@ -12,7 +12,7 @@
  */
 declare(strict_types=1);
 
-namespace Modules\ContractManagement\Models;
+namespace Modules\ContractManagement\Models\Attribute;
 
 use Modules\Attribute\Models\AttributeType;
 use phpOMS\DataStorage\Database\Mapper\DataMapperFactory;
@@ -20,7 +20,7 @@ use phpOMS\DataStorage\Database\Mapper\DataMapperFactory;
 /**
  * Contract mapper class.
  *
- * @package Modules\ContractManagement\Models
+ * @package Modules\ContractManagement\Models\Attribute
  * @license OMS License 2.0
  * @link    https://jingga.app
  * @since   1.0.0
diff --git a/Models/ContractAttributeValueL11nMapper.php b/Models/Attribute/ContractAttributeValueL11nMapper.php
similarity index 91%
rename from Models/ContractAttributeValueL11nMapper.php
rename to Models/Attribute/ContractAttributeValueL11nMapper.php
index 7128ad2..409350d 100644
--- a/Models/ContractAttributeValueL11nMapper.php
+++ b/Models/Attribute/ContractAttributeValueL11nMapper.php
@@ -4,7 +4,7 @@
  *
  * PHP Version 8.1
  *
- * @package   Modules\ContractManagement\Models
+ * @package   Modules\ContractManagement\Models\Attribute
  * @copyright Dennis Eichhorn
  * @license   OMS License 2.0
  * @version   1.0.0
@@ -12,7 +12,7 @@
  */
 declare(strict_types=1);
 
-namespace Modules\ContractManagement\Models;
+namespace Modules\ContractManagement\Models\Attribute;
 
 use phpOMS\DataStorage\Database\Mapper\DataMapperFactory;
 use phpOMS\Localization\BaseStringL11n;
@@ -20,7 +20,7 @@ use phpOMS\Localization\BaseStringL11n;
 /**
  * Contract mapper class.
  *
- * @package Modules\ContractManagement\Models
+ * @package Modules\ContractManagement\Models\Attribute
  * @license OMS License 2.0
  * @link    https://jingga.app
  * @since   1.0.0
diff --git a/Models/ContractAttributeValueMapper.php b/Models/Attribute/ContractAttributeValueMapper.php
similarity index 95%
rename from Models/ContractAttributeValueMapper.php
rename to Models/Attribute/ContractAttributeValueMapper.php
index c454180..3ab204b 100644
--- a/Models/ContractAttributeValueMapper.php
+++ b/Models/Attribute/ContractAttributeValueMapper.php
@@ -4,7 +4,7 @@
  *
  * PHP Version 8.1
  *
- * @package   Modules\ContractManagement\Models
+ * @package   Modules\ContractManagement\Models\Attribute
  * @copyright Dennis Eichhorn
  * @license   OMS License 2.0
  * @version   1.0.0
@@ -12,7 +12,7 @@
  */
 declare(strict_types=1);
 
-namespace Modules\ContractManagement\Models;
+namespace Modules\ContractManagement\Models\Attribute;
 
 use Modules\Attribute\Models\AttributeValue;
 use phpOMS\DataStorage\Database\Mapper\DataMapperFactory;
@@ -20,7 +20,7 @@ use phpOMS\DataStorage\Database\Mapper\DataMapperFactory;
 /**
  * Contract mapper class.
  *
- * @package Modules\ContractManagement\Models
+ * @package Modules\ContractManagement\Models\Attribute
  * @license OMS License 2.0
  * @link    https://jingga.app
  * @since   1.0.0
diff --git a/Models/ContractMapper.php b/Models/ContractMapper.php
index 2988d4f..eadca71 100755
--- a/Models/ContractMapper.php
+++ b/Models/ContractMapper.php
@@ -17,6 +17,7 @@ declare(strict_types=1);
 namespace Modules\ContractManagement\Models;
 
 use Modules\Admin\Models\AccountMapper;
+use Modules\ContractManagement\Models\Attribute\ContractAttributeMapper;
 use Modules\Media\Models\MediaMapper;
 use Modules\Organization\Models\UnitMapper;
 use Modules\Editor\Models\EditorDocMapper;