diff --git a/core/components/minishop3/src/Model/msProductCreateProcessor.php b/core/components/minishop3/src/Model/msProductCreateProcessor.php
new file mode 100644
index 00000000..734a2c43
--- /dev/null
+++ b/core/components/minishop3/src/Model/msProductCreateProcessor.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace MiniShop3\Model;
+
+/**
+ * Resolver target for MODX Resource\Create::getInstance() when class_key is msProduct.
+ *
+ * @see \MODX\Revolution\Processors\Resource\Create::getInstance()
+ */
+class msProductCreateProcessor extends \MiniShop3\Processors\Product\Create
+{
+}
diff --git a/core/components/minishop3/src/Model/msProductUpdateProcessor.php b/core/components/minishop3/src/Model/msProductUpdateProcessor.php
new file mode 100644
index 00000000..7d8b77c0
--- /dev/null
+++ b/core/components/minishop3/src/Model/msProductUpdateProcessor.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace MiniShop3\Model;
+
+/**
+ * Resolver target for MODX Resource\Update::getInstance() when class_key is msProduct.
+ *
+ * @see \MODX\Revolution\Processors\Resource\Update::getInstance()
+ */
+class msProductUpdateProcessor extends \MiniShop3\Processors\Product\Update
+{
+}
diff --git a/core/components/minishop3/src/Processors/Product/Create.php b/core/components/minishop3/src/Processors/Product/Create.php
index 41a3bd0e..b9893b08 100644
--- a/core/components/minishop3/src/Processors/Product/Create.php
+++ b/core/components/minishop3/src/Processors/Product/Create.php
@@ -8,6 +8,8 @@
 
 class Create extends CreateProcessor
 {
+    use ProductDataPayloadTrait;
+
     public $classKey = msProduct::class;
     public $languageTopics = ['resource', 'minishop3:default'];
     public $permission = 'msproduct_save';
@@ -57,6 +59,8 @@ public function beforeSet()
             ),
         ]);
 
+        $this->captureProductDataPayload();
+
         $properties = $this->getProperties();
         $options = [];
         $hadOptionFieldsInRequest = false;
@@ -91,6 +95,7 @@ public function beforeSet()
     public function beforeSave()
     {
         $this->object->set('isfolder', false);
+
         return parent::beforeSave();
     }
 
@@ -114,6 +119,9 @@ public function afterSave()
 
         $result = parent::afterSave();
 
+        // msProductData needs resource id; composite may not persist payload fields on insert (#297).
+        $this->persistProductDataPayload();
+
         // Same contract as Update::afterSave (#199): only sync when the request contained options-* keys (#257).
         if ($this->ms3ProductFormOptions !== null) {
             /** @var \MiniShop3\Model\msProductData $productData */
diff --git a/core/components/minishop3/src/Processors/Product/ProductDataPayloadTrait.php b/core/components/minishop3/src/Processors/Product/ProductDataPayloadTrait.php
new file mode 100644
index 00000000..9edcbba3
--- /dev/null
+++ b/core/components/minishop3/src/Processors/Product/ProductDataPayloadTrait.php
@@ -0,0 +1,160 @@
+<?php
+
+namespace MiniShop3\Processors\Product;
+
+use MiniShop3\Model\msProduct;
+use MiniShop3\Model\msProductData;
+
+/**
+ * Applies msProductData fields from the `Data` block and flat request keys (#297).
+ *
+ * Resource Create/Update call `$object->fromArray($properties)` without ignoreInvalid,
+ * so msProductData columns must be applied explicitly. On Create the msProductData row
+ * needs a resource id — persist in afterSave(); on Update beforeSave() is enough.
+ *
+ * @property \MODX\Revolution\modX $modx
+ * @property msProduct $object
+ */
+trait ProductDataPayloadTrait
+{
+    private const PRODUCT_DATA_PROPERTY = 'Data';
+
+    /** @var array<string, mixed>|null */
+    protected ?array $ms3ProductDataPayload = null;
+
+    protected function captureProductDataPayload(): void
+    {
+        $this->ms3ProductDataPayload = null;
+
+        $payload = $this->getProperty(self::PRODUCT_DATA_PROPERTY);
+        if ($payload === null || $payload === '') {
+            return;
+        }
+
+        $this->unsetProperty(self::PRODUCT_DATA_PROPERTY);
+
+        if (is_string($payload)) {
+            $decoded = json_decode($payload, true);
+            if (is_array($decoded)) {
+                $payload = $decoded;
+            } else {
+                return;
+            }
+        }
+
+        if (is_array($payload)) {
+            $this->ms3ProductDataPayload = $payload;
+        }
+    }
+
+    /**
+     * Assign msProductData fields on the in-memory composite (Update / pre-save).
+     */
+    protected function applyProductDataPayload(): void
+    {
+        $this->assignProductDataPayload(false);
+    }
+
+    /**
+     * Assign and save msProductData after the resource id exists (Create).
+     */
+    protected function persistProductDataPayload(): bool
+    {
+        return $this->assignProductDataPayload(true);
+    }
+
+    private function assignProductDataPayload(bool $persist): bool
+    {
+        if (!$this->object instanceof msProduct) {
+            return false;
+        }
+
+        if ($persist && (int) $this->object->get('id') <= 0) {
+            return false;
+        }
+
+        $this->ensureProductDataFieldMapLoaded();
+
+        $allowedFields = $this->getAllowedProductDataFieldNames();
+        $flatFields = $this->collectFlatProductDataFields($allowedFields);
+        $nestedFields = $this->collectNestedProductDataFields($allowedFields);
+
+        if ($flatFields === [] && $nestedFields === []) {
+            return false;
+        }
+
+        $productData = $this->object->loadData();
+
+        if ($persist) {
+            $productData->set('id', (int) $this->object->get('id'));
+        }
+
+        $this->assignProductDataFields($productData, $flatFields);
+        $this->assignProductDataFields($productData, $nestedFields);
+
+        return $persist ? (bool) $productData->save() : true;
+    }
+
+    private function ensureProductDataFieldMapLoaded(): void
+    {
+        if (!$this->modx->services->has('ms3')) {
+            return;
+        }
+
+        $this->modx->services->get('ms3')->loadMap();
+    }
+
+    /**
+     * @return array<string, true>
+     */
+    private function getAllowedProductDataFieldNames(): array
+    {
+        $fields = array_flip($this->object->getDataFieldsNames());
+        unset($fields['id']);
+
+        return $fields;
+    }
+
+    /**
+     * @param array<string, true> $allowedFields
+     * @return array<string, mixed>
+     */
+    private function collectFlatProductDataFields(array $allowedFields): array
+    {
+        $fields = [];
+
+        foreach ($this->getProperties() as $key => $value) {
+            if (!isset($allowedFields[$key])) {
+                continue;
+            }
+            $fields[$key] = $value;
+        }
+
+        return $fields;
+    }
+
+    /**
+     * @param array<string, true> $allowedFields
+     * @return array<string, mixed>
+     */
+    private function collectNestedProductDataFields(array $allowedFields): array
+    {
+        if ($this->ms3ProductDataPayload === null) {
+            return [];
+        }
+
+        return array_intersect_key($this->ms3ProductDataPayload, $allowedFields);
+    }
+
+    /**
+     * @param array<string, mixed> $fields
+     */
+    private function assignProductDataFields(msProductData $productData, array $fields): void
+    {
+        if ($fields === []) {
+            return;
+        }
+
+        $productData->fromArray($fields, '', true, true);
+    }
+}
diff --git a/core/components/minishop3/src/Processors/Product/Update.php b/core/components/minishop3/src/Processors/Product/Update.php
index fdefec18..4bc07eb3 100644
--- a/core/components/minishop3/src/Processors/Product/Update.php
+++ b/core/components/minishop3/src/Processors/Product/Update.php
@@ -11,6 +11,8 @@
 
 class Update extends UpdateProcessor
 {
+    use ProductDataPayloadTrait;
+
     public $classKey = msProduct::class;
     public $languageTopics = ['resource', 'minishop3:default'];
     public $permission = 'msproduct_save';
@@ -48,6 +50,9 @@ public static function getInstance(modX $modx, $className, $properties = [])
     public function beforeSet()
     {
         $this->ms3ProductFormOptions = null;
+
+        $this->captureProductDataPayload();
+
         $properties = $this->getProperties();
         $options = [];
         $hadOptionFieldsInRequest = false;
@@ -109,6 +114,7 @@ public function checkFriendlyAlias()
     public function beforeSave()
     {
         $this->object->set('isfolder', false);
+        $this->applyProductDataPayload();
 
         return parent::beforeSave();
     }