diff --git a/packages/sylius/src/cart/use-update-item.tsx b/packages/sylius/src/cart/use-update-item.tsx
index 950f422e1..8cfb903bf 100644
--- a/packages/sylius/src/cart/use-update-item.tsx
+++ b/packages/sylius/src/cart/use-update-item.tsx
@@ -1,20 +1,79 @@
-import { MutationHook } from '@vercel/commerce/utils/types'
+import {
+  HookFetcherContext,
+  MutationHook,
+  MutationHookContext,
+} from '@vercel/commerce/utils/types'
 import useUpdateItem, {
   UseUpdateItem,
 } from '@vercel/commerce/cart/use-update-item'
+import { getCartToken } from '../utils/token/cart-token'
+import { useCallback } from 'react'
+import useCart from './use-cart'
+import { LineItem, UpdateItemHook } from '@vercel/commerce/types/cart'
+import { ValidationError } from '@vercel/commerce/utils/errors'
+import { normalizeCart } from '../utils/normalize/normalize-cart'
 
 export default useUpdateItem as UseUpdateItem<any>
 
 export const handler: MutationHook<any> = {
   fetchOptions: {
-    query: '',
+    url: '/api/v2/shop/orders',
+    method: 'PATCH',
+  },
+  fetcher: async ({
+    input: { itemId, item },
+    options,
+    fetch,
+  }: HookFetcherContext<UpdateItemHook>) => {
+    const syliusCart = await fetch({
+      url: `${options.url}/${getCartToken()}/items/${itemId}`,
+      method: options.method,
+      body: {
+        quantity: item.quantity,
+      },
+      variables: {
+        contentType: 'application/merge-patch+json',
+      },
+    })
+    return normalizeCart(syliusCart)
   },
-  async fetcher({ input, options, fetch }) {},
   useHook:
-    ({ fetch }) =>
-    () => {
-      return async function addItem() {
-        return {}
-      }
+    ({ fetch }: MutationHookContext<UpdateItemHook>) =>
+    (
+      ctx: {
+        item?: LineItem
+        wait?: number
+      } = {}
+    ) => {
+      const { item } = ctx
+      const { mutate, data: cartData } = useCart() as any
+
+      return useCallback(
+        async function addItem(input) {
+          const firstLineItem = cartData.lineItems[0]
+          const itemId = item?.id || firstLineItem.id
+          const productId = item?.productId || firstLineItem.productId
+          const variantId = item?.variant.id || firstLineItem.variant.id
+          if (!itemId) {
+            throw new ValidationError({
+              message: 'Invalid input used for this operation',
+            })
+          }
+          const data = await fetch({
+            input: {
+              item: {
+                productId,
+                variantId,
+                quantity: input.quantity,
+              },
+              itemId,
+            },
+          })
+          console.log('update quantity', data)
+          await mutate(data, false)
+          return data
+        },
+        [fetch, mutate]
+      )
     },
 }
diff --git a/packages/sylius/src/fetcher.ts b/packages/sylius/src/fetcher.ts
index 73eecde27..94c5ef53c 100644
--- a/packages/sylius/src/fetcher.ts
+++ b/packages/sylius/src/fetcher.ts
@@ -9,13 +9,14 @@ const fetcher: Fetcher = async ({
   body,
   variables = {
     useToken: true,
+    contentType: 'application/json',
   },
 }) => {
   const token = getCustomerToken()
   const res = await fetch(API_URL + url!, {
     method: method,
     headers: {
-      'Content-Type': 'application/json',
+      'Content-Type': variables.contentType,
       accept: 'application/json, text/plain',
       ...(token && variables.useToken
         ? { Authorization: `Bearer ${token}` }