diff --git a/app/Http/Requests/App/InventoryStoreRequest.php b/app/Http/Requests/App/InventoryStoreRequest.php
index 7b1a88a..b6a5669 100644
--- a/app/Http/Requests/App/InventoryStoreRequest.php
+++ b/app/Http/Requests/App/InventoryStoreRequest.php
@@ -21,6 +21,7 @@ public function rules(): array
         return [
             // Campos de Inventory
             'name' => ['required', 'string', 'max:100'],
+            'key_sat' => ['nullable', 'integer', 'max:9'],
             'sku' => ['nullable', 'string', 'max:50', 'unique:inventories,sku'],
             'barcode' => ['nullable', 'string', 'unique:inventories,barcode'],
             'category_id' => ['required', 'exists:categories,id'],
diff --git a/app/Http/Requests/App/InventoryUpdateRequest.php b/app/Http/Requests/App/InventoryUpdateRequest.php
index 2168aa3..5b87efd 100644
--- a/app/Http/Requests/App/InventoryUpdateRequest.php
+++ b/app/Http/Requests/App/InventoryUpdateRequest.php
@@ -23,6 +23,7 @@ public function rules(): array
         return [
             // Campos de Inventory
             'name' => ['nullable', 'string', 'max:100'],
+            'key_sat' => ['nullable', 'string', 'max:9'],
             'sku' => ['nullable', 'string', 'max:50'],
             'barcode' => ['nullable', 'string', 'unique:inventories,barcode,' . $inventoryId],
             'category_id' => ['nullable', 'exists:categories,id'],
diff --git a/app/Models/Inventory.php b/app/Models/Inventory.php
index a59513b..f66d299 100644
--- a/app/Models/Inventory.php
+++ b/app/Models/Inventory.php
@@ -22,6 +22,7 @@ class Inventory extends Model
         'category_id',
         'unit_of_measure_id',
         'name',
+        'key_sat',
         'sku',
         'barcode',
         'track_serials',
diff --git a/app/Models/InventoryWarehouse.php b/app/Models/InventoryWarehouse.php
index dee1aa4..c353551 100644
--- a/app/Models/InventoryWarehouse.php
+++ b/app/Models/InventoryWarehouse.php
@@ -1,7 +1,10 @@
 <?php namespace App\Models;
 
+use App\Observers\InventoryWarehouseObserver;
+use Illuminate\Database\Eloquent\Attributes\ObservedBy;
 use Illuminate\Database\Eloquent\Model;
 
+#[ObservedBy([InventoryWarehouseObserver::class])]
 class InventoryWarehouse extends Model
 {
     protected $table = 'inventory_warehouse';
diff --git a/app/Observers/InventoryWarehouseObserver.php b/app/Observers/InventoryWarehouseObserver.php
new file mode 100644
index 0000000..f300c89
--- /dev/null
+++ b/app/Observers/InventoryWarehouseObserver.php
@@ -0,0 +1,69 @@
+<?php namespace App\Observers;
+/**
+ * @copyright (c) 2025 Notsoweb Software (https://notsoweb.com) - All Rights Reserved
+ */
+
+use App\Models\InventoryWarehouse;
+use App\Models\User;
+use App\Notifications\UserNotification;
+
+/**
+ * Observer de stock por almacén
+ *
+ * Envía notificación a administradores cuando el stock de un producto
+ * cruza el umbral mínimo (de disponible a bajo stock).
+ *
+ * @author Moisés Cortés C. <moises.cortes@notsoweb.com>
+ *
+ * @version 1.0.0
+ */
+class InventoryWarehouseObserver
+{
+    /**
+     * Roles que reciben alertas de stock bajo
+     */
+    protected array $notifiableRoles = ['developer', 'admin'];
+
+    /**
+     * Umbral por defecto cuando min_stock no está configurado
+     */
+    protected int $defaultThreshold = 5;
+
+    /**
+     * Detectar cuando el stock cruza el umbral mínimo hacia abajo
+     */
+    public function updated(InventoryWarehouse $inventoryWarehouse): void
+    {
+        $previousStock = (float) $inventoryWarehouse->getOriginal('stock');
+        $currentStock  = (float) $inventoryWarehouse->stock;
+        $threshold     = (float) ($inventoryWarehouse->min_stock ?? $this->defaultThreshold);
+
+        // Solo notificar si el stock CRUZÓ el umbral (no en cada update mientras ya esté bajo)
+        if ($previousStock >= $threshold && $currentStock < $threshold) {
+            $this->notifyLowStock($inventoryWarehouse, $currentStock);
+        }
+    }
+
+    /**
+     * Enviar notificación de stock bajo a usuarios con rol relevante
+     */
+    protected function notifyLowStock(InventoryWarehouse $inventoryWarehouse, float $currentStock): void
+    {
+        $inventoryWarehouse->load('inventory', 'warehouse');
+
+        $productName   = $inventoryWarehouse->inventory?->name ?? 'Producto desconocido';
+        $warehouseName = $inventoryWarehouse->warehouse?->name ?? 'Almacén desconocido';
+
+        $users = User::role($this->notifiableRoles)->get();
+
+        foreach ($users as $user) {
+            $user->notify(new UserNotification(
+                title: 'Stock bajo: ' . $productName,
+                description: "El producto \"{$productName}\" tiene {$currentStock} unidad(es) disponible(s) en \"{$warehouseName}\".",
+                type: 'warning',
+                timeout: 30,
+                save: true,
+            ));
+        }
+    }
+}
diff --git a/app/Services/ProductService.php b/app/Services/ProductService.php
index 87ae245..d276df3 100644
--- a/app/Services/ProductService.php
+++ b/app/Services/ProductService.php
@@ -11,6 +11,7 @@ public function createProduct(array $data)
         return DB::transaction(function () use ($data) {
             $inventory = Inventory::create([
                 'name' => $data['name'],
+                'key_sat' => $data['key_sat'] ?? null,
                 'sku' => $data['sku'],
                 'barcode' => $data['barcode'] ?? null,
                 'category_id' => $data['category_id'],
@@ -35,6 +36,7 @@ public function updateProduct(Inventory $inventory, array $data)
             // Actualizar campos de Inventory solo si están presentes
             $inventoryData = array_filter([
                 'name' => $data['name'] ?? null,
+                'key_sat' => $data['key_sat'] ?? null,
                 'sku' => $data['sku'] ?? null,
                 'barcode' => $data['barcode'] ?? null,
                 'category_id' => $data['category_id'] ?? null,
diff --git a/database/migrations/2026_02_23_131314_add_key_sat_to_inventories_table.php b/database/migrations/2026_02_23_131314_add_key_sat_to_inventories_table.php
new file mode 100644
index 0000000..457588d
--- /dev/null
+++ b/database/migrations/2026_02_23_131314_add_key_sat_to_inventories_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('inventories', function (Blueprint $table) {
+            $table->integer('key_sat')->nullable()->after('name');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('inventories', function (Blueprint $table) {
+            $table->dropColumn('key_sat');
+        });
+    }
+};