Cart Module

The Cart Module is the @medusajs/cart NPM package that provides cart-related features in your Medusa and Node.js applications.

---

Features

Cart Management

Store and manage carts, including their addresses, line items, shipping methods, and more.

const cart = await cartModuleService.create({
  currency_code: "usd",
  shipping_address: {
    address_1: "1512 Barataria Blvd",
    country_code: "us",
  },
  items: [
    {
      title: "Shirt",
      unit_price: 1000,
      quantity: 1,
    },
  ],
})

Apply Promotions

Apply promotions or discounts to line items and shipping methods by adding adjustment lines that are factored into their subtotals.

const lineAdjustments =
  await cartModuleService.addLineItemAdjustments({
    item_id: "cali_123",
    code: "50OFF",
    amount: 500,
  })

const shippingAdjustments =
  await cartModuleService.addShippingMethodAdjustments({
    shipping_method_id: "casm_123",
    code: "FREESHIPPING",
    amount: 1000,
  })

Cart Context and Scoping

A cart is scoped to a sales channel, region, and a customer.

When used with their respective modules and other commerce modules, you benefit from features like:

• Checking product availability in a sales channel.
• Retrieving pricing per region.
• Applying promotions based on the customer's group.

---

Configure Cart Module

After installing the @medusajs/cart package in your Medusa application, add it to the modules object in medusa-config.js:

medusa-config.js

const modules = {
  // ...
  cart: {
    resolve: "@medusajs/cart",
  },
}

---

How to Use Cart Module's Service

You can use the Cart Module's main service by resolving from the dependency container the resource ModuleRegistrationName.CART imported from @medusajs/modules-sdk.

For example:

• API Route
• Subscriber
• Workflow Step

import { MedusaRequest, MedusaResponse } from "@medusajs/medusa"
import { ICartModuleService } from "@medusajs/types"
import { ModuleRegistrationName } from "@medusajs/modules-sdk"
import { res } from "express"

export async function GET(
  req: MedusaRequest,
  res: MedusaResponse
): Promise<void> {
  const cartModuleService: ICartModuleService =
    req.scope.resolve(ModuleRegistrationName.CART)

  res.json({
    carts: await cartModuleService.list(),
  })
}

import { SubscriberArgs } from "@medusajs/medusa"
import { ICartModuleService } from "@medusajs/types"
import { ModuleRegistrationName } from "@medusajs/modules-sdk"

export default async function subscriberHandler({
  container,
}: SubscriberArgs) {
  const cartModuleService: ICartModuleService =
    container.resolve(ModuleRegistrationName.CART)

  const carts = await cartModuleService.list()
}

import { createStep } from "@medusajs/workflows-sdk"
import { ICartModuleService } from "@medusajs/types"
import { ModuleRegistrationName } from "@medusajs/modules-sdk"

const step1 = createStep("step-1", async (_, context) => {
  const cartModuleService: ICartModuleService =
    context.container.resolve(
      ModuleRegistrationName.CART
    )
  const carts = await cartModuleService.list()
})