From 29dca1ca481e34cc17678b7b4f0e854d3a404acd Mon Sep 17 00:00:00 2001
From: Adrien de Peretti <adrien.deperetti@gmail.com>
Date: Thu, 11 Sep 2025 12:12:13 +0200
Subject: [PATCH] fix(): update cart line item route fetching (#13477)

**What**
Remove cart fetching before workflow which fetch the cart as well
---
 .changeset/spotty-hotels-speak.md             |  6 ++++
 .../workflows/update-line-item-in-cart.ts     |  7 ++++
 .../carts/[id]/line-items/[line_id]/route.ts  | 32 ++-----------------
 3 files changed, 15 insertions(+), 30 deletions(-)
 create mode 100644 .changeset/spotty-hotels-speak.md

diff --git a/.changeset/spotty-hotels-speak.md b/.changeset/spotty-hotels-speak.md
new file mode 100644
index 0000000000..a533576091
--- /dev/null
+++ b/.changeset/spotty-hotels-speak.md
@@ -0,0 +1,6 @@
+---
+"@medusajs/medusa": patch
+"@medusajs/core-flows": patch
+---
+
+fix(): update cart line item route fetching
diff --git a/packages/core/core-flows/src/cart/workflows/update-line-item-in-cart.ts b/packages/core/core-flows/src/cart/workflows/update-line-item-in-cart.ts
index 286f89c34e..86e51a1775 100644
--- a/packages/core/core-flows/src/cart/workflows/update-line-item-in-cart.ts
+++ b/packages/core/core-flows/src/cart/workflows/update-line-item-in-cart.ts
@@ -134,6 +134,13 @@ export const updateLineItemInCartWorkflow = createWorkflow(
         input: UpdateLineItemInCartWorkflowInputDTO & AdditionalData
       }) => {
         const item = data.cart.items.find((i) => i.id === data.input.item_id)!
+        if (!item) {
+          throw new MedusaError(
+            MedusaError.Types.NOT_FOUND,
+            `Line item with id: ${data.input.item_id} was not found`
+          )
+        }
+
         const variantIds = [item?.variant_id].filter(Boolean)
         return { item, variantIds }
       }
diff --git a/packages/medusa/src/api/store/carts/[id]/line-items/[line_id]/route.ts b/packages/medusa/src/api/store/carts/[id]/line-items/[line_id]/route.ts
index 41d94eeade..852e4081df 100644
--- a/packages/medusa/src/api/store/carts/[id]/line-items/[line_id]/route.ts
+++ b/packages/medusa/src/api/store/carts/[id]/line-items/[line_id]/route.ts
@@ -2,10 +2,9 @@ import {
   deleteLineItemsWorkflowId,
   updateLineItemInCartWorkflowId,
 } from "@medusajs/core-flows"
-import { prepareListQuery } from "@medusajs/framework"
 import { MedusaRequest, MedusaResponse } from "@medusajs/framework/http"
 import { HttpTypes } from "@medusajs/framework/types"
-import { MedusaError, Modules } from "@medusajs/framework/utils"
+import { Modules } from "@medusajs/framework/utils"
 import { refetchCart } from "../../../helpers"
 import { StoreUpdateCartLineItemType } from "../../../validators"
 
@@ -13,38 +12,11 @@ export const POST = async (
   req: MedusaRequest<StoreUpdateCartLineItemType>,
   res: MedusaResponse<HttpTypes.StoreCartResponse>
 ) => {
-  // TODO: Move this to the workflow when the query to line item is fixed
-  const cart = await refetchCart(
-    req.params.id,
-    req.scope,
-    prepareListQuery(
-      {},
-      {
-        defaults: [
-          "id",
-          "region_id",
-          "customer_id",
-          "sales_channel_id",
-          "currency_code",
-          "*items",
-        ],
-      }
-    ).remoteQueryConfig.fields
-  )
-
-  const item = cart.items?.find((i) => i.id === req.params.line_id)
-  if (!item) {
-    throw new MedusaError(
-      MedusaError.Types.NOT_FOUND,
-      `Line item with id: ${req.params.line_id} was not found`
-    )
-  }
-
   const we = req.scope.resolve(Modules.WORKFLOW_ENGINE)
   await we.run(updateLineItemInCartWorkflowId, {
     input: {
       cart_id: req.params.id,
-      item_id: item.id,
+      item_id: req.params.line_id,
       update: req.validatedBody,
     },
     transactionId: "cart-update-item-" + req.params.id,