diff --git a/app/Http/Controllers/App/InventoryController.php b/app/Http/Controllers/App/InventoryController.php
index ce07967..97eda9f 100644
--- a/app/Http/Controllers/App/InventoryController.php
+++ b/app/Http/Controllers/App/InventoryController.php
@@ -25,7 +25,7 @@ public function __construct(
     public function index(Request $request)
     {
         $products = Inventory::with(['category', 'price'])->withCount('serials')
-                ->where('is_active', true);
+        ->where('is_active', true);
 
 
         // Filtro por búsqueda de texto (nombre, SKU, código de barras)
@@ -90,6 +90,50 @@ public function destroy(Inventory $inventario)
         return ApiResponse::OK->response();
     }
 
+    /**
+     * Obtener productos disponibles en un almacén específico
+     */
+    public function getProductsByWarehouse(Request $request, int $warehouseId)
+    {
+        $query = Inventory::query()
+            ->with(['category', 'price'])
+            ->where('is_active', true)
+            ->whereHas('warehouses', function ($q) use ($warehouseId) {
+                $q->where('warehouse_id', $warehouseId)
+                  ->where('stock', '>', 0);
+            });
+
+        // Filtro por búsqueda de texto
+        if ($request->has('q') && $request->q) {
+            $query->where(function($q) use ($request) {
+                $q->where('name', 'like', "%{$request->q}%")
+                  ->orWhere('sku', 'like', "%{$request->q}%")
+                  ->orWhere('barcode', $request->q);
+            });
+        }
+
+        // Filtro por categoría
+        if ($request->has('category_id') && $request->category_id) {
+            $query->where('category_id', $request->category_id);
+        }
+
+        $products = $query->orderBy('name')->get();
+
+        // Agregar el stock específico de este almacén a cada producto
+        $products->each(function ($product) use ($warehouseId) {
+            $warehouseStock = $product->warehouses()
+                ->where('warehouse_id', $warehouseId)
+                ->first();
+
+            $product->warehouse_stock = $warehouseStock ? $warehouseStock->pivot->stock : 0;
+        });
+
+        return ApiResponse::OK->response([
+            'products' => $products,
+            'warehouse_id' => $warehouseId,
+        ]);
+    }
+
     /**
      * Importar productos desde Excel
      */
diff --git a/app/Http/Controllers/App/InventoryMovementController.php b/app/Http/Controllers/App/InventoryMovementController.php
index 757140d..8baa690 100644
--- a/app/Http/Controllers/App/InventoryMovementController.php
+++ b/app/Http/Controllers/App/InventoryMovementController.php
@@ -29,6 +29,14 @@ public function index(Request $request)
         $query = InventoryMovement::with(['inventory', 'warehouseFrom', 'warehouseTo', 'user'])
             ->orderBy('created_at', 'desc');
 
+        if ($request->has('q') && $request->q){
+            $query->whereHas('inventory', function($qy) use ($request){
+                $qy->where('name', 'like', "%{$request->q}%")
+                    ->orWhere('sku', 'like', "%{$request->q}%")
+                    ->orWhere('barcode', $request->q);
+            });
+        }
+
         if ($request->has('movement_type')) {
             $query->where('movement_type', $request->movement_type);
         }
@@ -82,12 +90,25 @@ public function show(int $id)
     public function entry(InventoryEntryRequest $request)
     {
         try {
-            $movement = $this->movementService->entry($request->validated());
+            $validated = $request->validated();
+
+            if(isset($validated['products'])){
+                $movements = $this->movementService->bulkEntry($validated);
+
+                return ApiResponse::CREATED->response([
+                    'message' => 'Entrada registrada correctamente',
+                    'movement' => $movements,
+                    'total_products' => count($movements),
+                ]);
+            } else {
+                $movement = $this->movementService->entry($validated);
+
+                return ApiResponse::CREATED->response([
+                    'message' => 'Entrada registrada correctamente',
+                    'movement' => $movement->load(['inventory', 'warehouseTo']),
+                ]);
+            }
 
-            return ApiResponse::CREATED->response([
-                'message' => 'Entrada registrada correctamente',
-                'movement' => $movement->load(['inventory', 'warehouseTo']),
-            ]);
         } catch (\Exception $e) {
             return ApiResponse::BAD_REQUEST->response([
                 'message' => $e->getMessage()
@@ -101,12 +122,24 @@ public function entry(InventoryEntryRequest $request)
     public function exit(InventoryExitRequest $request)
     {
         try {
-            $movement = $this->movementService->exit($request->validated());
+        $validated = $request->validated();
 
-            return ApiResponse::CREATED->response([
-                'message' => 'Salida registrada correctamente',
-                'movement' => $movement->load(['inventory', 'warehouseFrom']),
-            ]);
+            if(isset($validated['products'])){
+                $movements = $this->movementService->bulkExit($validated);
+
+                return ApiResponse::CREATED->response([
+                    'message' => 'Salidas registradas correctamente',
+                    'movements' => $movements,
+                    'total_products' => count($movements),
+                ]);
+            } else {
+                $movement = $this->movementService->exit($validated);
+
+                return ApiResponse::CREATED->response([
+                    'message' => 'Salida registrada correctamente',
+                    'movement' => $movement->load(['inventory', 'warehouseFrom']),
+                ]);
+            }
         } catch (\Exception $e) {
             return ApiResponse::BAD_REQUEST->response([
                 'message' => $e->getMessage()
@@ -120,12 +153,24 @@ public function exit(InventoryExitRequest $request)
     public function transfer(InventoryTransferRequest $request)
     {
         try {
-            $movement = $this->movementService->transfer($request->validated());
+            $validated = $request->validated();
 
-            return ApiResponse::CREATED->response([
-                'message' => 'Traspaso registrado correctamente',
-                'movement' => $movement->load(['inventory', 'warehouseFrom', 'warehouseTo']),
-            ]);
+            if(isset($validated['products'])){
+                $movements = $this->movementService->bulkTransfer($validated);
+
+                return ApiResponse::CREATED->response([
+                    'message' => 'Traspasos registrados correctamente',
+                    'movements' => $movements,
+                    'total_products' => count($movements),
+                ]);
+            } else {
+                $movement = $this->movementService->transfer($validated);
+
+                return ApiResponse::CREATED->response([
+                    'message' => 'Traspaso registrado correctamente',
+                    'movement' => $movement->load(['inventory', 'warehouseFrom', 'warehouseTo']),
+                ]);
+            }
         } catch (\Exception $e) {
             return ApiResponse::BAD_REQUEST->response([
                 'message' => $e->getMessage()
diff --git a/app/Http/Controllers/App/ReturnController.php b/app/Http/Controllers/App/ReturnController.php
index 5dfca5c..20265e5 100644
--- a/app/Http/Controllers/App/ReturnController.php
+++ b/app/Http/Controllers/App/ReturnController.php
@@ -28,6 +28,10 @@ public function index(Request $request)
             'details.inventory',
         ])->orderBy('created_at', 'desc');
 
+        if (!auth()->user()->hasRole('admin')) {
+            $query->where('user_id', auth()->id());
+        }
+
         // Filtros
         if ($request->has('q') && $request->q) {
             $query->where('return_number', 'like', "%{$request->q}%")
@@ -72,6 +76,12 @@ public function show(Returns $return)
             'cashRegister',
         ]);
 
+        if (!auth()->user()->hasRole('admin') && $return->user_id !== auth()->id()) {
+            return ApiResponse::FORBIDDEN->response([
+                'message' => 'No tienes permiso para ver esta venta.'
+            ]);
+        }
+
         return ApiResponse::OK->response([
             'model' => $return,
         ]);
@@ -101,6 +111,12 @@ public function store(ReturnStoreRequest $request)
      */
     public function cancel(Returns $return)
     {
+        if (!auth()->user()->hasRole('admin') && $return->user_id !== auth()->id()) {
+            return ApiResponse::FORBIDDEN->response([
+                'message' => 'No tienes permiso para cancelar esta venta.'
+            ]);
+        }
+
         try {
             $cancelledReturn = $this->returnService->cancelReturn($return);
 
diff --git a/app/Http/Controllers/App/SaleController.php b/app/Http/Controllers/App/SaleController.php
index 8d92b24..fdce925 100644
--- a/app/Http/Controllers/App/SaleController.php
+++ b/app/Http/Controllers/App/SaleController.php
@@ -20,11 +20,18 @@ public function index(Request $request)
         $sales = Sale::with(['details.inventory', 'details.serials', 'user', 'client'])
             ->orderBy('created_at', 'desc');
 
+        // Filtrar por usuario: solo admin puede ver todas las ventas
+        if (!auth()->user()->hasRole('admin')) {
+            $sales->where('user_id', auth()->id());
+        }
+
         if ($request->has('q') && $request->q) {
-            $sales->where('invoice_number', 'like', "%{$request->q}%")
-                ->orWhereHas('user', fn($query) =>
-                    $query->where('name', 'like', "%{$request->q}%")
-                );
+            $sales->where(function ($query) use ($request) {
+                $query->where('invoice_number', 'like', "%{$request->q}%")
+                    ->orWhereHas('user', fn($q) =>
+                        $q->where('name', 'like', "%{$request->q}%")
+                    );
+            });
         }
 
         if ($request->has('cash_register_id')) {
@@ -42,6 +49,13 @@ public function index(Request $request)
 
     public function show(Sale $sale)
     {
+        // Solo admin puede ver ventas de otros usuarios
+        if (!auth()->user()->hasRole('admin') && $sale->user_id !== auth()->id()) {
+            return ApiResponse::FORBIDDEN->response([
+                'message' => 'No tienes permiso para ver esta venta.'
+            ]);
+        }
+
         return ApiResponse::OK->response([
             'model' => $sale->load(['details.inventory', 'user', 'client'])
         ]);
@@ -58,6 +72,13 @@ public function store(SaleStoreRequest $request)
 
     public function cancel(Sale $sale)
     {
+        // Solo admin puede cancelar ventas de otros usuarios
+        if (!auth()->user()->hasRole('admin') && $sale->user_id !== auth()->id()) {
+            return ApiResponse::FORBIDDEN->response([
+                'message' => 'No tienes permiso para cancelar esta venta.'
+            ]);
+        }
+
         try {
             $cancelledSale = $this->saleService->cancelSale($sale);
 
diff --git a/app/Http/Requests/App/InventoryEntryRequest.php b/app/Http/Requests/App/InventoryEntryRequest.php
index 7826ffb..f6dc9a7 100644
--- a/app/Http/Requests/App/InventoryEntryRequest.php
+++ b/app/Http/Requests/App/InventoryEntryRequest.php
@@ -13,11 +13,26 @@ public function authorize(): bool
 
     public function rules(): array
     {
+        if ($this->has('products')) {
+            return [
+                'warehouse_id' => 'required|exists:warehouses,id',
+                'invoice_reference' => 'required|string|max:255',
+                'notes' => 'nullable|string|max:1000',
+
+                // Validación del array de productos
+                'products' => 'required|array|min:1',
+                'products.*.inventory_id' => 'required|exists:inventories,id',
+                'products.*.quantity' => 'required|integer|min:1',
+                'products.*.unit_cost' => 'required|numeric|min:0',
+            ];
+        }
+
         return [
             'inventory_id' => 'required|exists:inventories,id',
             'warehouse_id' => 'required|exists:warehouses,id',
             'quantity' => 'required|integer|min:1',
-            'invoice_reference' => 'nullable|string|max:255',
+            'unit_cost' => 'required|numeric|min:0',
+            'invoice_reference' => 'required|string|max:255',
             'notes' => 'nullable|string|max:1000',
         ];
     }
@@ -25,12 +40,27 @@ public function rules(): array
     public function messages(): array
     {
         return [
+            // Mensajes para entrada única
             'inventory_id.required' => 'El producto es requerido',
             'inventory_id.exists' => 'El producto no existe',
+
+            // Mensajes para entrada múltiple
+            'products.required' => 'Debe incluir al menos un producto',
+            'products.*.inventory_id.required' => 'El producto es requerido',
+            'products.*.inventory_id.exists' => 'El producto no existe',
+            'products.*.quantity.required' => 'La cantidad es requerida',
+            'products.*.quantity.min' => 'La cantidad debe ser al menos 1',
+            'products.*.unit_cost.required' => 'El costo unitario es requerido',
+            'products.*.unit_cost.numeric' => 'El costo unitario debe ser un número',
+            'products.*.unit_cost.min' => 'El costo unitario no puede ser negativo',
+
+            // Mensajes comunes
             'warehouse_id.required' => 'El almacén es requerido',
             'warehouse_id.exists' => 'El almacén no existe',
             'quantity.required' => 'La cantidad es requerida',
             'quantity.min' => 'La cantidad debe ser al menos 1',
+            'unit_cost.required' => 'El costo unitario es requerido',
+            'invoice_reference.required' => 'La referencia de la factura es requerida',
         ];
     }
 }
diff --git a/app/Http/Requests/App/InventoryExitRequest.php b/app/Http/Requests/App/InventoryExitRequest.php
index a62a463..b544e3c 100644
--- a/app/Http/Requests/App/InventoryExitRequest.php
+++ b/app/Http/Requests/App/InventoryExitRequest.php
@@ -13,6 +13,20 @@ public function authorize(): bool
 
     public function rules(): array
     {
+        // Si tiene "products" array, es salida múltiple
+        if ($this->has('products')) {
+            return [
+                'warehouse_id' => 'required|exists:warehouses,id',
+                'notes' => 'nullable|string|max:1000',
+
+                // Validación del array de productos
+                'products' => 'required|array|min:1',
+                'products.*.inventory_id' => 'required|exists:inventories,id',
+                'products.*.quantity' => 'required|integer|min:1',
+            ];
+        }
+
+        // Salida única (formato original)
         return [
             'inventory_id' => 'required|exists:inventories,id',
             'warehouse_id' => 'required|exists:warehouses,id',
@@ -24,8 +38,18 @@ public function rules(): array
     public function messages(): array
     {
         return [
+            // Mensajes para salida única
             'inventory_id.required' => 'El producto es requerido',
             'inventory_id.exists' => 'El producto no existe',
+
+            // Mensajes para salida múltiple
+            'products.required' => 'Debe incluir al menos un producto',
+            'products.*.inventory_id.required' => 'El producto es requerido',
+            'products.*.inventory_id.exists' => 'El producto no existe',
+            'products.*.quantity.required' => 'La cantidad es requerida',
+            'products.*.quantity.min' => 'La cantidad debe ser al menos 1',
+
+            // Mensajes comunes
             'warehouse_id.required' => 'El almacén es requerido',
             'warehouse_id.exists' => 'El almacén no existe',
             'quantity.required' => 'La cantidad es requerida',
diff --git a/app/Http/Requests/App/InventoryImportRequest.php b/app/Http/Requests/App/InventoryImportRequest.php
index 7c9b2d2..2395951 100644
--- a/app/Http/Requests/App/InventoryImportRequest.php
+++ b/app/Http/Requests/App/InventoryImportRequest.php
@@ -55,7 +55,7 @@ public static function rowRules(): array
             'codigo_barras' => ['nullable', 'string', 'max:100'],
             'categoria' => ['nullable', 'string', 'max:100'],
             'stock' => ['required', 'integer', 'min:0'],
-            'costo' => ['required', 'numeric', 'min:0'],
+            'costo' => ['nullable', 'numeric', 'min:0'],
             'precio_venta' => ['required', 'numeric', 'min:0'],
             'impuesto' => ['nullable', 'numeric', 'min:0', 'max:100'],
         ];
@@ -73,7 +73,6 @@ public static function rowMessages(): array
             'stock.required' => 'El stock es requerido.',
             'stock.integer' => 'El stock debe ser un número entero.',
             'stock.min' => 'El stock no puede ser negativo.',
-            'costo.required' => 'El costo es requerido.',
             'costo.numeric' => 'El costo debe ser un número.',
             'costo.min' => 'El costo no puede ser negativo.',
             'precio_venta.required' => 'El precio de venta es requerido.',
diff --git a/app/Http/Requests/App/InventoryStoreRequest.php b/app/Http/Requests/App/InventoryStoreRequest.php
index 8220098..e58aed7 100644
--- a/app/Http/Requests/App/InventoryStoreRequest.php
+++ b/app/Http/Requests/App/InventoryStoreRequest.php
@@ -27,8 +27,8 @@ public function rules(): array
             'track_serials' => ['nullable', 'boolean'],
 
             // Campos de Price
-            'cost' => ['required', 'numeric', 'min:0'],
-            'retail_price' => ['required', 'numeric', 'min:0', 'gt:cost'],
+            'cost' => ['nullable', 'numeric', 'min:0'],
+            'retail_price' => ['required', 'numeric', 'min:0'],
             'tax' => ['nullable', 'numeric', 'min:0', 'max:100'],
         ];
     }
@@ -48,9 +48,6 @@ public function messages(): array
             'category_id.required' => 'La categoría es obligatoria.',
             'category_id.exists' => 'La categoría seleccionada no es válida.',
             // Mensajes de Price
-            'cost.required' => 'El costo es obligatorio.',
-            'cost.numeric' => 'El costo debe ser un número.',
-            'cost.min' => 'El costo no puede ser negativo.',
             'retail_price.required' => 'El precio de venta es obligatorio.',
             'retail_price.numeric' => 'El precio de venta debe ser un número.',
             'retail_price.min' => 'El precio de venta no puede ser negativo.',
@@ -60,4 +57,22 @@ public function messages(): array
             'tax.max' => 'El impuesto no puede exceder el 100%.',
         ];
     }
+
+    /**
+     * Validación condicional: retail_price > cost solo si cost > 0
+     */
+    public function withValidator($validator)
+    {
+        $validator->after(function ($validator) {
+            $cost = $this->input('cost');
+            $retailPrice = $this->input('retail_price');
+
+            if ($cost !== null && $cost > 0 && $retailPrice !== null && $retailPrice <= $cost) {
+                $validator->errors()->add(
+                    'retail_price',
+                    'El precio de venta debe ser mayor que el costo.'
+                );
+            }
+        });
+    }
 }
diff --git a/app/Http/Requests/App/InventoryTransferRequest.php b/app/Http/Requests/App/InventoryTransferRequest.php
index ea46b52..a7c1f0b 100644
--- a/app/Http/Requests/App/InventoryTransferRequest.php
+++ b/app/Http/Requests/App/InventoryTransferRequest.php
@@ -13,6 +13,21 @@ public function authorize(): bool
 
     public function rules(): array
     {
+        // Si tiene "products" array, es traspaso múltiple
+        if ($this->has('products')) {
+            return [
+                'warehouse_from_id' => 'required|exists:warehouses,id',
+                'warehouse_to_id' => 'required|exists:warehouses,id|different:warehouse_from_id',
+                'notes' => 'nullable|string|max:1000',
+
+                // Validación del array de productos
+                'products' => 'required|array|min:1',
+                'products.*.inventory_id' => 'required|exists:inventories,id',
+                'products.*.quantity' => 'required|integer|min:1',
+            ];
+        }
+
+        // Traspaso único (formato original)
         return [
             'inventory_id' => 'required|exists:inventories,id',
             'warehouse_from_id' => 'required|exists:warehouses,id',
@@ -25,8 +40,18 @@ public function rules(): array
     public function messages(): array
     {
         return [
+            // Mensajes para traspaso único
             'inventory_id.required' => 'El producto es requerido',
             'inventory_id.exists' => 'El producto no existe',
+
+            // Mensajes para traspaso múltiple
+            'products.required' => 'Debe incluir al menos un producto',
+            'products.*.inventory_id.required' => 'El producto es requerido',
+            'products.*.inventory_id.exists' => 'El producto no existe',
+            'products.*.quantity.required' => 'La cantidad es requerida',
+            'products.*.quantity.min' => 'La cantidad debe ser al menos 1',
+
+            // Mensajes comunes
             'warehouse_from_id.required' => 'El almacén origen es requerido',
             'warehouse_from_id.exists' => 'El almacén origen no existe',
             'warehouse_to_id.required' => 'El almacén destino es requerido',
diff --git a/app/Http/Requests/App/InventoryUpdateRequest.php b/app/Http/Requests/App/InventoryUpdateRequest.php
index b053748..c47cf0c 100644
--- a/app/Http/Requests/App/InventoryUpdateRequest.php
+++ b/app/Http/Requests/App/InventoryUpdateRequest.php
@@ -30,7 +30,7 @@ public function rules(): array
 
             // Campos de Price
             'cost' => ['nullable', 'numeric', 'min:0'],
-            'retail_price' => ['nullable', 'numeric', 'min:0', 'gt:cost'],
+            'retail_price' => ['nullable', 'numeric', 'min:0'],
             'tax' => ['nullable', 'numeric', 'min:0', 'max:100'],
         ];
     }
@@ -58,4 +58,22 @@ public function messages(): array
             'tax.max' => 'El impuesto no puede exceder el 100%.',
         ];
     }
+
+    /**
+     * Validación condicional: retail_price > cost solo si cost > 0
+     */
+    public function withValidator($validator)
+    {
+        $validator->after(function ($validator) {
+            $cost = $this->input('cost');
+            $retailPrice = $this->input('retail_price');
+
+            if ($cost !== null && $cost > 0 && $retailPrice !== null && $retailPrice <= $cost) {
+                $validator->errors()->add(
+                    'retail_price',
+                    'El precio de venta debe ser mayor que el costo.'
+                );
+            }
+        });
+    }
 }
diff --git a/app/Http/Requests/App/PriceUpdateRequest.php b/app/Http/Requests/App/PriceUpdateRequest.php
index 0bb3885..e8a116a 100644
--- a/app/Http/Requests/App/PriceUpdateRequest.php
+++ b/app/Http/Requests/App/PriceUpdateRequest.php
@@ -20,7 +20,7 @@ public function rules(): array
     {
         return [
             'cost' => ['nullable', 'numeric', 'min:0'],
-            'retail_price' => ['nullable', 'numeric', 'min:0', 'gt:cost'],
+            'retail_price' => ['nullable', 'numeric', 'min:0'],
             'tax' => ['nullable', 'numeric', 'min:0', 'max:100'],
         ];
     }
@@ -38,4 +38,22 @@ public function messages(): array
             'tax.max' => 'El impuesto no puede exceder el 100%.',
         ];
     }
+
+    /**
+     * Validación condicional: retail_price > cost solo si cost > 0
+     */
+    public function withValidator($validator)
+    {
+        $validator->after(function ($validator) {
+            $cost = $this->input('cost');
+            $retailPrice = $this->input('retail_price');
+
+            if ($cost !== null && $cost > 0 && $retailPrice !== null && $retailPrice <= $cost) {
+                $validator->errors()->add(
+                    'retail_price',
+                    'El precio de venta debe ser mayor que el costo.'
+                );
+            }
+        });
+    }
 }
diff --git a/app/Imports/ProductsImport.php b/app/Imports/ProductsImport.php
index de148e3..07b4992 100644
--- a/app/Imports/ProductsImport.php
+++ b/app/Imports/ProductsImport.php
@@ -81,16 +81,17 @@ public function model(array $row)
                 $existingInventory = Inventory::where('barcode', trim($row['codigo_barras']))->first();
             }
 
-            // Si el producto ya existe, solo agregar stock y seriales
+            // Si el producto ya existe, solo agregar stock y costo
             if ($existingInventory) {
                 return $this->updateExistingProduct($existingInventory, $row);
             }
 
-            // Producto nuevo: validar precios
-            $costo = (float) $row['costo'];
+            // Producto nuevo: obtener valores
+            $costo = isset($row['costo']) && $row['costo'] !== '' ? (float) $row['costo'] : 0;
             $precioVenta = (float) $row['precio_venta'];
 
-            if ($precioVenta <= $costo) {
+            // Validar precio > costo solo si costo > 0
+            if ($costo > 0 && $precioVenta <= $costo) {
                 $this->skipped++;
                 $this->errors[] = "Fila con producto '{$row['nombre']}': El precio de venta ($precioVenta) debe ser mayor que el costo ($costo)";
                 return null;
@@ -123,8 +124,16 @@ public function model(array $row)
                 'tax' => !empty($row['impuesto']) ? (float) $row['impuesto'] : 0,
             ]);
 
-            // Crear números de serie si se proporcionan
-            $this->addSerials($inventory, $row['numeros_serie'] ?? null, $row['stock'] ?? 0);
+             // Agregar stock inicial si existe
+            $stockFromExcel = (int) ($row['stock'] ?? 0);
+            if ($stockFromExcel > 0) {
+                $this->addStockWithCost(
+                    $inventory,
+                    $stockFromExcel,
+                    $costo,
+                    $row['numeros_serie'] ?? null
+                );
+            }
 
             $this->imported++;
 
@@ -137,64 +146,79 @@ public function model(array $row)
     }
 
     /**
-     * Actualiza un producto existente: suma stock y agrega seriales nuevos
+     * Actualiza un producto existente: suma stock y actualiza costo
      */
     private function updateExistingProduct(Inventory $inventory, array $row)
     {
-        $serialsAdded = 0;
-        $serialsSkipped = 0;
         $mainWarehouseId = $this->movementService->getMainWarehouseId();
+        $stockToAdd = (int) ($row['stock'] ?? 0);
+        $costo = isset($row['costo']) && $row['costo'] !== '' ? (float) $row['costo'] : null;
 
-        // Agregar seriales nuevos (ignorar duplicados)
-        if (!empty($row['numeros_serie'])) {
-            $serials = explode(',', $row['numeros_serie']);
+        // Si hay stock para agregar
+        if ($stockToAdd > 0) {
+            // Si tiene números de serie
+            if (!empty($row['numeros_serie'])) {
+                $serials = explode(',', $row['numeros_serie']);
+                $serialsAdded = 0;
+                $serialsSkipped = 0;
 
-            foreach ($serials as $serial) {
-                $serial = trim($serial);
-                if (empty($serial)) continue;
+                foreach ($serials as $serial) {
+                    $serial = trim($serial);
+                    if (empty($serial)) continue;
 
-                // Verificar si el serial ya existe (global, no solo en este producto)
-                $exists = InventorySerial::where('serial_number', $serial)->exists();
+                    // Verificar si el serial ya existe
+                    $exists = InventorySerial::where('serial_number', $serial)->exists();
 
-                if (!$exists) {
-                    InventorySerial::create([
-                        'inventory_id' => $inventory->id,
-                        'warehouse_id' => $mainWarehouseId,
-                        'serial_number' => $serial,
-                        'status' => 'disponible',
-                    ]);
-                    $serialsAdded++;
-                } else {
-                    $serialsSkipped++;
+                    if (!$exists) {
+                        InventorySerial::create([
+                            'inventory_id' => $inventory->id,
+                            'warehouse_id' => $mainWarehouseId,
+                            'serial_number' => $serial,
+                            'status' => 'disponible',
+                        ]);
+                        $serialsAdded++;
+                    } else {
+                        $serialsSkipped++;
+                    }
+                }
+
+                // Sincronizar stock basado en seriales
+                $inventory->syncStock();
+
+                if ($serialsSkipped > 0) {
+                    $this->errors[] = "Producto '{$inventory->name}': {$serialsSkipped} seriales ya existían y fueron ignorados";
                 }
             }
 
-            // Sincronizar stock basado en seriales disponibles
-            $inventory->syncStock();
-        } else {
-            // Producto sin seriales: sumar stock en almacén principal
-            $stockToAdd = (int) ($row['stock'] ?? 0);
-            if ($stockToAdd > 0) {
+            // Registrar movimiento de entrada con costo si existe
+            if ($costo !== null && $costo > 0) {
+                $this->movementService->entry([
+                    'inventory_id' => $inventory->id,
+                    'warehouse_id' => $mainWarehouseId,
+                    'quantity' => $stockToAdd,
+                    'unit_cost' => $costo,
+                    'invoice_reference' => 'IMP-' . date('YmdHis'),
+                    'notes' => 'Importación desde Excel - actualización',
+                ]);
+            } else {
+                // Sin costo, solo agregar stock sin movimiento de entrada
                 $this->movementService->updateWarehouseStock($inventory->id, $mainWarehouseId, $stockToAdd);
             }
         }
 
         $this->updated++;
 
-        if ($serialsSkipped > 0) {
-            $this->errors[] = "Producto '{$inventory->name}': {$serialsSkipped} seriales ya existían y fueron ignorados";
-        }
-
         return null; // No retornar modelo para evitar que Maatwebsite intente guardarlo
     }
 
     /**
-     * Agrega seriales a un producto nuevo
+     * Agrega stock inicial a un producto nuevo con registro de movimiento
      */
-    private function addSerials(Inventory $inventory, ?string $serialsString, int $stockFromExcel)
+    private function addStockWithCost(Inventory $inventory, int $quantity, float $cost, ?string $serialsString): void
     {
         $mainWarehouseId = $this->movementService->getMainWarehouseId();
 
+        // Si tiene números de serie
         if (!empty($serialsString)) {
             $serials = explode(',', $serialsString);
 
@@ -209,12 +233,24 @@ private function addSerials(Inventory $inventory, ?string $serialsString, int $s
                     ]);
                 }
             }
+
+            // Sincronizar stock basado en seriales
             $inventory->syncStock();
+        }
+
+        // Registrar movimiento de entrada con costo si existe
+        if ($cost > 0) {
+            $this->movementService->entry([
+                'inventory_id' => $inventory->id,
+                'warehouse_id' => $mainWarehouseId,
+                'quantity' => $quantity,
+                'unit_cost' => $cost,
+                'invoice_reference' => 'IMP-' . date('YmdHis'),
+                'notes' => 'Importación desde Excel - stock inicial',
+            ]);
         } else {
-            // Producto sin seriales: registrar stock en almacén principal
-            if ($stockFromExcel > 0) {
-                $this->movementService->updateWarehouseStock($inventory->id, $mainWarehouseId, $stockFromExcel);
-            }
+            // Sin costo, solo agregar stock
+            $this->movementService->updateWarehouseStock($inventory->id, $mainWarehouseId, $quantity);
         }
     }
 
diff --git a/app/Models/InventoryMovement.php b/app/Models/InventoryMovement.php
index ff84638..d62dad3 100644
--- a/app/Models/InventoryMovement.php
+++ b/app/Models/InventoryMovement.php
@@ -12,6 +12,7 @@ class InventoryMovement extends Model
         'warehouse_to_id',
         'movement_type',
         'quantity',
+        'unit_cost',
         'reference_type',
         'reference_id',
         'user_id',
@@ -21,6 +22,7 @@ class InventoryMovement extends Model
 
     protected $casts = [
         'quantity' => 'integer',
+        'unit_cost' => 'decimal:2',
         'created_at' => 'datetime',
     ];
 
diff --git a/app/Services/InventoryMovementService.php b/app/Services/InventoryMovementService.php
index 3ba41be..15fae7e 100644
--- a/app/Services/InventoryMovementService.php
+++ b/app/Services/InventoryMovementService.php
@@ -1,4 +1,6 @@
-<?php namespace App\Services;
+<?php
+
+namespace App\Services;
 
 use App\Models\Inventory;
 use App\Models\InventoryMovement;
@@ -14,7 +16,7 @@
 class InventoryMovementService
 {
     /**
-     * Entrada de inventario (compra, ajuste positivo)
+     * Entrada de inventario
      */
     public function entry(array $data): InventoryMovement
     {
@@ -22,6 +24,22 @@ public function entry(array $data): InventoryMovement
             $inventory = Inventory::findOrFail($data['inventory_id']);
             $warehouse = Warehouse::findOrFail($data['warehouse_id']);
             $quantity = $data['quantity'];
+            $unitCost = $data['unit_cost'];
+
+            //Obtener stock actual para calcular costo promedio ponderado
+            $curentStock = $inventory->stock;
+            $currentCost = $inventory->price?->cost ?? 0.00;
+
+            // Calcular nuevo costo promedio ponderado
+            $newCost = $this->calculateWeightedAverageCost(
+                $curentStock,
+                $currentCost,
+                $quantity,
+                $unitCost
+            );
+
+            // Actualizar costo en prices
+            $this->updateProductCost($inventory, $newCost);
 
             // Actualizar stock en inventory_warehouse
             $this->updateWarehouseStock($inventory->id, $warehouse->id, $quantity);
@@ -33,6 +51,7 @@ public function entry(array $data): InventoryMovement
                 'warehouse_to_id' => $warehouse->id,
                 'movement_type' => 'entry',
                 'quantity' => $quantity,
+                'unit_cost' => $unitCost,
                 'user_id' => auth()->id(),
                 'notes' => $data['notes'] ?? null,
                 'invoice_reference' => $data['invoice_reference'] ?? null,
@@ -40,6 +59,166 @@ public function entry(array $data): InventoryMovement
         });
     }
 
+    /**
+     * Entrada múltiple de inventario (varios productos)
+     */
+    public function bulkEntry(array $data): array
+    {
+        return DB::transaction(function () use ($data) {
+            $warehouse = Warehouse::findOrFail($data['warehouse_id']);
+            $movements = [];
+
+            foreach ($data['products'] as $productData) {
+                $inventory = Inventory::findOrFail($productData['inventory_id']);
+                $quantity = $productData['quantity'];
+                $unitCost = $productData['unit_cost'];
+
+                // Obtener stock actual para calcular costo promedio ponderado
+                $currentStock = $inventory->stock;
+                $currentCost = $inventory->price?->cost ?? 0.00;
+
+                // Calcular nuevo costo promedio ponderado
+                $newCost = $this->calculateWeightedAverageCost(
+                    $currentStock,
+                    $currentCost,
+                    $quantity,
+                    $unitCost
+                );
+
+                // Actualizar costo en prices
+                $this->updateProductCost($inventory, $newCost);
+
+                // Actualizar stock en inventory_warehouse
+                $this->updateWarehouseStock($inventory->id, $warehouse->id, $quantity);
+
+                // Registrar movimiento
+                $movement = InventoryMovement::create([
+                    'inventory_id' => $inventory->id,
+                    'warehouse_from_id' => null,
+                    'warehouse_to_id' => $warehouse->id,
+                    'movement_type' => 'entry',
+                    'quantity' => $quantity,
+                    'unit_cost' => $unitCost,
+                    'user_id' => auth()->id(),
+                    'notes' => $data['notes'] ?? null,
+                    'invoice_reference' => $data['invoice_reference'],
+                ]);
+
+                $movements[] = $movement->load(['inventory', 'warehouseTo']);
+            }
+
+            return $movements;
+        });
+    }
+
+    /**
+     * Salida múltiple de inventario (varios productos)
+     */
+    public function bulkExit(array $data): array
+    {
+        return DB::transaction(function () use ($data) {
+            $warehouse = Warehouse::findOrFail($data['warehouse_id']);
+            $movements = [];
+
+            foreach ($data['products'] as $productData) {
+                $inventory = Inventory::findOrFail($productData['inventory_id']);
+                $quantity = $productData['quantity'];
+
+                // Validar stock disponible
+                $this->validateStock($inventory->id, $warehouse->id, $quantity);
+
+                // Decrementar stock en inventory_warehouse
+                $this->updateWarehouseStock($inventory->id, $warehouse->id, -$quantity);
+
+                // Registrar movimiento
+                $movement = InventoryMovement::create([
+                    'inventory_id' => $inventory->id,
+                    'warehouse_from_id' => $warehouse->id,
+                    'warehouse_to_id' => null,
+                    'movement_type' => 'exit',
+                    'quantity' => $quantity,
+                    'user_id' => auth()->id(),
+                    'notes' => $data['notes'] ?? null,
+                ]);
+
+                $movements[] = $movement->load(['inventory', 'warehouseFrom']);
+            }
+
+            return $movements;
+        });
+    }
+
+    /**
+     * Traspaso múltiple entre almacenes (varios productos)
+     */
+    public function bulkTransfer(array $data): array
+    {
+        return DB::transaction(function () use ($data) {
+            $warehouseFrom = Warehouse::findOrFail($data['warehouse_from_id']);
+            $warehouseTo = Warehouse::findOrFail($data['warehouse_to_id']);
+            $movements = [];
+
+            // Validar que no sea el mismo almacén
+            if ($warehouseFrom->id === $warehouseTo->id) {
+                throw new \Exception('No se puede traspasar al mismo almacén.');
+            }
+
+            foreach ($data['products'] as $productData) {
+                $inventory = Inventory::findOrFail($productData['inventory_id']);
+                $quantity = $productData['quantity'];
+
+                // Validar stock disponible en almacén origen
+                $this->validateStock($inventory->id, $warehouseFrom->id, $quantity);
+
+                // Decrementar en origen
+                $this->updateWarehouseStock($inventory->id, $warehouseFrom->id, -$quantity);
+
+                // Incrementar en destino
+                $this->updateWarehouseStock($inventory->id, $warehouseTo->id, $quantity);
+
+                // Registrar movimiento
+                $movement = InventoryMovement::create([
+                    'inventory_id' => $inventory->id,
+                    'warehouse_from_id' => $warehouseFrom->id,
+                    'warehouse_to_id' => $warehouseTo->id,
+                    'movement_type' => 'transfer',
+                    'quantity' => $quantity,
+                    'user_id' => auth()->id(),
+                    'notes' => $data['notes'] ?? null,
+                ]);
+
+                $movements[] = $movement->load(['inventory', 'warehouseFrom', 'warehouseTo']);
+            }
+
+            return $movements;
+        });
+    }
+
+    /**
+     * Calcular costo promedio ponderado
+     */
+    protected function calculateWeightedAverageCost(
+        int $currentStock,
+        float $currentCost,
+        int $entryQuantity,
+        float $entryCost
+    ): float {
+        if ($currentStock <= 0) {
+            return $entryCost;
+        }
+        $totalValue = ($currentStock * $currentCost) + ($entryQuantity * $entryCost);
+        $totalQuantity = $currentStock + $entryQuantity;
+        return round($totalValue / $totalQuantity, 2);
+    }
+
+    protected function updateProductCost(Inventory $inventory, float $newCost): void
+    {
+        $inventory->price()->updateOrCreate(
+            ['inventory_id' => $inventory->id],
+            ['cost' => $newCost]
+        );
+    }
+
     /**
      * Salida de inventario (merma, ajuste negativo, robo, daño)
      */
diff --git a/app/Services/ProductService.php b/app/Services/ProductService.php
index 4ac362c..2de721d 100644
--- a/app/Services/ProductService.php
+++ b/app/Services/ProductService.php
@@ -19,7 +19,7 @@ public function createProduct(array $data)
 
             Price::create([
                 'inventory_id' => $inventory->id,
-                'cost' => $data['cost'],
+                'cost' => $data['cost'] ?? 0,
                 'retail_price' => $data['retail_price'],
                 'tax' => $data['tax'] ?? 16.00,
             ]);
diff --git a/database/migrations/2026_02_06_101139_add_unit_cost_to_inventory_movements_table.php b/database/migrations/2026_02_06_101139_add_unit_cost_to_inventory_movements_table.php
new file mode 100644
index 0000000..6881f8e
--- /dev/null
+++ b/database/migrations/2026_02_06_101139_add_unit_cost_to_inventory_movements_table.php
@@ -0,0 +1,28 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('inventory_movements', function (Blueprint $table) {
+            $table->decimal('unit_cost', 15, 2)->nullable()->after('quantity');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('inventory_movements', function (Blueprint $table) {
+            $table->dropColumn('unit_cost');
+        });
+    }
+};
diff --git a/database/migrations/2026_02_06_103956_make_cost_nullable_in_prices_table.php b/database/migrations/2026_02_06_103956_make_cost_nullable_in_prices_table.php
new file mode 100644
index 0000000..2e48f64
--- /dev/null
+++ b/database/migrations/2026_02_06_103956_make_cost_nullable_in_prices_table.php
@@ -0,0 +1,28 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('prices', function (Blueprint $table) {
+            $table->decimal('cost', 15, 2)->nullable()->change();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('prices', function (Blueprint $table) {
+            $table->decimal('cost', 15, 2)->nullable(false)->change();
+        });
+    }
+};
diff --git a/routes/api.php b/routes/api.php
index 48b0e2c..8ecec5f 100644
--- a/routes/api.php
+++ b/routes/api.php
@@ -36,9 +36,10 @@
     // Tus rutas protegidas
 
     //INVENTARIO
-    Route::resource('inventario', InventoryController::class);
+    Route::get('inventario/almacen/{warehouse}', [InventoryController::class, 'getProductsByWarehouse']);
     Route::post('inventario/import', [InventoryController::class, 'import']);
     Route::get('inventario/template/download', [InventoryController::class, 'downloadTemplate']);
+    Route::resource('inventario', InventoryController::class);
 
     // NÚMEROS DE SERIE DE INVENTARIO
     Route::resource('inventario.serials', InventorySerialController::class);