---
title: 'New: Support for nested cart lines - Shopify developer changelog'
description: >-
  Shopify’s developer changelog documents all changes to Shopify’s platform.
  Find the latest news and learn about new platform opportunities.
source_url:
  html: 'https://shopify.dev/changelog/posts/new-support-for-nested-cart-lines'
  md: 'https://shopify.dev/changelog/posts/new-support-for-nested-cart-lines.md'
metadata:
  effectiveApiVersion: 2025-10
  affectedApi:
    - displayName: Functions
      handle: functions-api
    - displayName: Checkout UI
      handle: checkout-ui-api
    - displayName: Customer Account API
      handle: customer-account-graphql
    - displayName: Customer Accounts
      handle: customer-accounts
    - displayName: Liquid
      handle: liquid
    - displayName: Storefront API
      handle: storefront-graphql
    - displayName: Events & webhooks
      handle: webhook
  primaryTag:
    displayName: API
    handle: api
  secondaryTag:
    displayName: New
    handle: new
  indicatesActionRequired: false
  createdAt: '2025-08-05T10:51:12-04:00'
  postedAt: '2025-08-06T16:45:00-04:00'
  updatedAt: '2025-08-06T16:59:21-04:00'
  effectiveAt: '2025-08-06T12:00:00-04:00'
---

August 6, 2025

# New: Support for nested cart lines

DateAugust 6, 2025

Version[2025-10](https://shopify.dev/changelog?api_version=2025-10)

FlagsNew

SurfacesAPI

Affected APIs[Functions](https://shopify.dev/changelog?api_type=functions-api)[Checkout UI](https://shopify.dev/changelog?api_type=checkout-ui-api)[Customer Account API](https://shopify.dev/changelog?api_type=customer-account-graphql)[Customer Accounts](https://shopify.dev/changelog?api_type=customer-accounts)[Liquid](https://shopify.dev/changelog?api_type=liquid)[Storefront API](https://shopify.dev/changelog?api_type=storefront-graphql)[Events & webhooks](https://shopify.dev/changelog?api_type=webhook)

New fields have been introduced to enable parent-child (nested) relationships between cart lines, supporting use cases such as warranties, engravings, and gift-wrapping.

* Nested cart lines are now supported in the Cart AJAX API, and as of version 2025-10, in Storefront API and Checkout UI Extensions.

* Nested (child) lines reference their parent using a dedicated parent field: Use `parentId` or `parent_line_key` (Cart AJAX API), `parentID` (Checkout UI Extensions), `parent.lineId` or `parent.merchandiseId` (Storefront API).

To learn more about the impacted APIs and fields, click [here](https://shopify.dev/docs/apps/build/product-merchandising/nested-cart-lines).