diff --git a/src/Base/PostType/PostTypeServiceProvider.php b/src/Base/PostType/PostTypeServiceProvider.php
index 43ec494..feac399 100644
--- a/src/Base/PostType/PostTypeServiceProvider.php
+++ b/src/Base/PostType/PostTypeServiceProvider.php
@@ -45,13 +45,16 @@ public function orderByPublishedDate(WP_Query $query): void
      */
     public function registerPostTypes(): void
     {
-        if (function_exists('register_extended_post_type')) {
-            $this->configPostTypes = apply_filters('owc/openpub-base/before-register-posttypes', $this->plugin->config->get('posttypes'));
-            foreach ($this->configPostTypes as $postTypeName => $postType) {
-                // Examples of registering post types: http://johnbillion.com/extended-cpts/
-                register_extended_post_type($postTypeName, $postType['args'], $postType['names']);
-            }
-        }
+		if (!function_exists('register_extended_post_type')) {
+			return;
+		}
+
+		$this->configPostTypes = apply_filters('owc/openpub-base/before-register-posttypes', $this->plugin->config->get('posttypes'));
+
+		foreach ($this->configPostTypes as $postTypeName => $postType) {
+			// Examples of registering post types: http://johnbillion.com/extended-cpts/
+			register_extended_post_type($postTypeName, $postType['args'], $postType['names']);
+		}
     }
 
     /**
diff --git a/src/Base/RestAPI/Controllers/ItemController.php b/src/Base/RestAPI/Controllers/ItemController.php
index aad0828..2d31361 100644
--- a/src/Base/RestAPI/Controllers/ItemController.php
+++ b/src/Base/RestAPI/Controllers/ItemController.php
@@ -55,7 +55,7 @@ protected function itemQueryBuilder(WP_REST_Request $request = null): Item
             $items->query(Item::addAudienceParameters($this->getAudienceParam($request)));
         }
 
-        return $items;
+		return apply_filters('owc/openpub/rest-api/items/query/parameters', $items, $request);
     }
 
     /**
@@ -146,6 +146,8 @@ protected function addRelated(array $item, WP_REST_Request $request): array
             $items->query(Item::addAudienceParameters($this->getAudienceParam($request)));
         }
 
+		$items = apply_filters('owc/openpub/rest-api/items/query/parameters', $items, $request);
+
         $query = new WP_Query($items->getQueryArgs());
         return array_map([$this, 'transform'], $query->posts);
     }