Package.json file

{
	"name": "busbasisberlin-monorepo",
	"version": "1.0.0",
	"description": "BusBasisBerlin MedusaJS E-commerce Monorepo",
	"private": true,
	"workspaces": [
		"busbasisberlin",
		"busbasisberlin-storefront"
	],
	"scripts": {
		"format": "npm run format:backend && npm run format:frontend",
		"format:backend": "cd busbasisberlin && npx prettier --write \"src/**/*.{ts,js,json}\" \"*.{ts,js,json}\"",
		"format:frontend": "cd busbasisberlin-storefront && npx prettier --write \"src/**/*.{ts,tsx,js,jsx,json}\" \"*.{ts,tsx,js,jsx,json}\"",
		"lint": "npm run lint:backend && npm run lint:frontend",
		"lint:backend": "cd busbasisberlin && npx eslint \"src/**/*.{ts,js}\" \"*.{ts,js}\" --fix || true",
		"lint:frontend": "cd busbasisberlin-storefront && npx eslint \"src/**/*.{ts,tsx,js,jsx}\" \"*.{ts,tsx,js,jsx}\" --fix || true",
		"format:all": "npm run format && npm run lint",
		"dev:backend": "cd busbasisberlin && npm run dev",
		"dev:frontend": "cd busbasisberlin-storefront && npm run dev",
		"build:backend": "cd busbasisberlin && npm run build",
		"build:frontend": "cd busbasisberlin-storefront && npm run build"
	},
	"devDependencies": {
		"prettier": "^3.0.0"
	},
	"keywords": [
		"medusajs",
		"ecommerce",
		"nextjs",
		"typescript",
		"monorepo"
	],
	"author": "BusBasisBerlin",
	"license": "MIT",
	"dependencies": {
		"ajv": "^8.17.1",
		"csv-parse": "^6.1.0",
		"csv-parser": "^3.2.0",
		"csv-writer": "^1.6.0",
		"gemeindeverzeichnis": "^0.1.0",
		"google-libphonenumber": "^3.2.42",
		"node-fetch": "^3.3.2",
		"openai": "^5.9.0",
		"p-limit": "^6.2.0",
		"pg": "^8.16.3",
		"postal-codes-js": "^2.5.2"
	},
	"packageManager": "npm@10.9.0",
	"overrides": {
		"@medusajs/ui": {
			"react": "19.0.0-rc-66855b96-20241106",
			"react-dom": "19.0.0-rc-66855b96-20241106"
		}
	}
}

Node.js version

v20.19.4

Database and its version

(PostgreSQL) 16.9 (Homebrew)

Operating system name and version

macOS Sequoia 15.7.3 (24G419)

Browser name

Google Chrome

What happended?

When using pickup/store-location shipping options, products with allow_backorder=true and inventory_quantity=0 are incorrectly flagged
with insufficient_inventory=true, which disables the pickup option at checkout.

Our Use Case

We have implemented a custom "Pickup at Storage Location" (Abholung am Lager) shipping option where:

• Customers can pick up their order at our physical warehouse location
• Payment is made in cash upon pickup
• This is a valid fulfillment method even for backorder items, since we can order the parts and notify the customer when ready for
  pickup

Expected behavior

Expected Behavior

Products with allow_backorder=true should bypass the inventory check, since they can be fulfilled through backorder regardless of
current stock levels. The pickup option should remain available.

Suggested Fix

1. Add "items.variant.allow_backorder" to the cart query fields (line 148):
   fields: [
   ...cartFieldsForPricingContext,
   "items.*",
   "items.variant.manage_inventory",
   "items.variant.allow_backorder", // Add this
   "items.variant.inventory_items.inventory_item_id",
   // ...
   ]

2. Check allow_backorder before flagging insufficient inventory (around line 333):
   const itemsAtLocationWithoutAvailableQuantity = cart.items.filter((item) => {
   if (!item.variant?.manage_inventory) {
   return false
   }
   // If backorder is allowed, item is always "available" for pickup
   if (item.variant?.allow_backorder) {
   return false
   }
   return item.variant.inventory_items.some((inventoryItem) => {
   // ... existing logic
   })
   })

Affected File

packages/core/core-flows/src/cart/workflows/list-shipping-options-for-cart.ts

Workaround

We are currently using patch-package to apply this fix locally.

Actual behavior

Current Behavior

In list-shipping-options-for-cart.ts, the insufficient_inventory calculation (lines 331-358) checks if items have available quantity at
the pickup location:

const itemsAtLocationWithoutAvailableQuantity = cart.items.filter((item) => {
if (!item.variant?.manage_inventory) {
return false
}
// Missing: check for allow_backorder
return item.variant.inventory_items.some((inventoryItem) => {
// ... checks location levels for available_quantity
})
})

This flags insufficient_inventory=true for any item with inventory_quantity=0, even if allow_backorder=true.

Link to reproduction repo

https://github.com/medusajs/medusa/blob/develop/packages/core/core-flows/src/cart/workflows/list-shipping -options-for-cart.ts#L331-L358 No separate reproduction repo needed - this is reproducible on any Medusa 2.x installation: 1. Create a stock location with a fulfillment set for pickup 2. Create a shipping option linked to that fulfillment set (e.g., "Store Pickup") 3. Create a product variant with: - manage_inventory: true - allow_backorder: true - inventory_quantity: 0 at the pickup location 4. Add the product to cart 5. Go to checkout and request shipping options via API