diff --git a/frontend/components/product/ProductDetails.vue b/frontend/components/product/ProductDetails.vue
index e0ca566..e0388e5 100644
--- a/frontend/components/product/ProductDetails.vue
+++ b/frontend/components/product/ProductDetails.vue
@@ -2,7 +2,7 @@
 
 // provide / inject
 
-import type { ProductVariantProvideType } from "~/pages/product/[id].vue";
+import type { ProductVariantProvideType } from "~/pages/product/types";
 
 const { selectedVariant } = inject("productVariant") as ProductVariantProvideType;
 
diff --git a/frontend/components/product/ProductHero.vue b/frontend/components/product/ProductHero.vue
index ba5321e..b853fff 100644
--- a/frontend/components/product/ProductHero.vue
+++ b/frontend/components/product/ProductHero.vue
@@ -5,13 +5,17 @@
 import useGetProduct from "~/composables/api/product/useGetProduct";
 import { sanitize } from "isomorphic-dompurify";
 import type { ProductVariantProvideType } from "~/pages/product/[id].vue";
+import useAddCartItem from "~/composables/api/orders/useAddCartItem";
+import { useAuth } from "~/composables/api/auth/useAuth";
 
 // state
 
 const route = useRoute();
 const id = route.params.id as string | undefined;
 
-const { data: product } = useGetProduct(id);
+const { token } = useAuth();
+const { data: product, refetch: refetchProduct } = useGetProduct(id);
+const { mutateAsync: addCartItem, isPending: isAddCartItemPending } = useAddCartItem();
 
 const selectedVariantId = ref(product.value!.variants[0].id);
 const selectedQuantity = ref(1);
@@ -23,6 +27,16 @@ const selectedColor = ref(product.value!.colors[0]);
 
 const { selectedVariant, changeSelectedVariant } = inject("productVariant") as ProductVariantProvideType;
 
+// method
+
+const addItemToCart = async () => {
+    await addCartItem({
+        id: selectedVariant.value!.id,
+        quantity: selectedQuantity.value
+    });
+    await refetchProduct();
+};
+
 // computed
 
 const sanitizedProductDescription = computed(() => {
@@ -44,7 +58,7 @@ watch(() => selectedColor.value, (newValue) => {
     immediate: true
 });
 
-watch(() => selectedVariant.value, (newValue) => {
+watch(() => selectedVariant.value!, (newValue) => {
     selectedQuantity.value = 1;
     selectedSlide.value = newValue.images[0].id;
 });
@@ -60,24 +74,24 @@ watch(() => selectedVariant.value, (newValue) => {
                 <div class="flex items-end gap-4">
                     <div class="flex flex-col gap-2">
                         <span
-                            v-if="selectedVariant.discount > 0"
+                            v-if="selectedVariant!.discount > 0"
                             class="typo-p-lg relative flex-center w-fit"
                             :class="'after:w-full after:h-[2px] after:bg-black after:absolute'"
                         >
-                            {{ selectedVariant.price }}
+                            {{ selectedVariant!.price }}
                         </span>
                         <span
                             class="typo-p-2xl relative flex-center w-fit font-medium"
                         >
-                            {{ selectedVariant.discount > 0 ? selectedVariant.price : selectedVariant.price }}
+                            {{ selectedVariant!.discount > 0 ? selectedVariant!.price : selectedVariant!.price }}
                         </span>
                     </div>
                     <div
-                        v-if="selectedVariant.discount > 0"
+                        v-if="selectedVariant!.discount > 0"
                         class="text-white bg-blue-500 mb-1 px-4 py-2 text-xs rounded-full flex items-center gap-1"
                     >
                         <Icon name="material-symbols:percent" class="size-4" />
-                        {{ selectedVariant.discount }}
+                        {{ selectedVariant!.discount }}
                         درصد تخفیف
                     </div>
                 </div>
@@ -87,7 +101,7 @@ watch(() => selectedVariant.value, (newValue) => {
         <Slider
             class="w-full lg:w-1/2 lg:max-w-[620px]"
             v-model:selectedSlide="selectedSlide"
-            :slides="selectedVariant.images"
+            :slides="selectedVariant!.images"
         />
         <div class="lg:w-1/2 flex flex-col gap-3 lg:mt-12">
             <NuxtLink
@@ -101,24 +115,24 @@ watch(() => selectedVariant.value, (newValue) => {
                 <div class="flex items-end gap-4">
                     <div class="flex flex-col gap-2">
                         <span
-                            v-if="selectedVariant.discount > 0"
+                            v-if="selectedVariant!.discount > 0"
                             class="typo-p-lg relative flex-center w-fit"
                             :class="'after:w-full after:h-[2px] after:bg-black after:absolute'"
                         >
-                            {{ selectedVariant.price }}
+                            {{ selectedVariant!.price }}
                         </span>
                         <span
                             class="typo-p-2xl relative flex-center w-fit font-medium"
                         >
-                            {{ selectedVariant.discount > 0 ? selectedVariant.price : selectedVariant.price }}
+                            {{ selectedVariant!.discount > 0 ? selectedVariant!.price : selectedVariant!.price }}
                         </span>
                     </div>
                     <div
-                        v-if="selectedVariant.discount > 0"
+                        v-if="selectedVariant!.discount > 0"
                         class="text-white bg-blue-500 mb-1 px-4 py-2 text-xs rounded-full flex items-center gap-1"
                     >
                         <Icon name="material-symbols:percent" class="size-4" />
-                        {{ selectedVariant.discount }}
+                        {{ selectedVariant!.discount }}
                         <span class="max-sm:hidden">درصد</span>
                         تخفیف
                     </div>
@@ -166,18 +180,50 @@ watch(() => selectedVariant.value, (newValue) => {
             <div class="w-full flex flex-col gap-6 mt-10">
 
                 <RemainQuantity
-                    :maxQuantity="selectedVariant.in_stock"
+                    :maxQuantity="selectedVariant!.in_stock"
                     :quantity="selectedQuantity"
                 />
 
                 <div class="w-full flex gap-3">
-                    <Button class="w-full rounded-full" end-icon="ci:plus">
-                        افزودن به سبد خرید
-                    </Button>
+                    <template v-if="token">
+                        <Button
+                            v-if="selectedVariant!.cart_quantity === 0"
+                            @click="addItemToCart"
+                            :loading="isAddCartItemPending"
+                            :disabled="isAddCartItemPending"
+                            class="w-full rounded-full"
+                            end-icon="ci:plus"
+                        >
+
+                            افزودن به سبد خرید
+                        </Button>
+                        <NuxtLink v-else to="/cart" class="w-full">
+                            <Button
+                                class="w-full rounded-full h-full"
+                                end-icon="ci:cart"
+                            >
+                                مشاهده در سبد خرید
+                            </Button>
+                        </NuxtLink>
+                    </template>
+                    <NuxtLink v-else to="/signin" class="w-full">
+                        <Button
+                            class="w-full rounded-full h-full"
+                            end-icon="ci:user"
+                        >
+                            ابتدا وارد شوید
+                        </Button>
+                    </NuxtLink>
+
                     <QuantityCounter
+                        v-if="selectedVariant!.cart_quantity === 0"
+                        :disable="isAddCartItemPending"
                         v-model="selectedQuantity"
-                        :max="selectedVariant.in_stock"
+                        :max="selectedVariant!.in_stock"
                     />
+
+                    <UpdateQuantity v-else />
+
                 </div>
 
                 <InfoCard />