Breaking down bundles at the cart level when using Loop and other subscription apps with Simple Bundles 2.0

How subscription apps work with Simple Bundles

This guide explains how to set up Simple Bundles 2.0 to work with subscription apps such as Loop and Ordergroove. For more details about this setup and how it works, you can learn more here: Creating bundles with a subscription plan like Recharge, Seal, and Appstle in Simple Bundles 2.0.

Simple Bundles 2.0 uses Shopify’s Cart Transform API to break down bundles into their child components at checkout. While this works well for standard (one-time) purchases, subscription apps require that individual child products, with the selling plan attached, be in the cart before checkout to process recurring orders properly.

Because Cart Transform runs during checkout and removes the parent bundle at that stage, the child products may not retain the selling plan in a way that subscription apps can process correctly. As a result, subscription bundle purchases may trigger the fallback order editing method.

This guide introduces a solution that expands subscription bundles at the add-to-cart stage when a selling plan is selected. This ensures the subscription app receives the individual child products with the selling plan properly attached.

By the end of this guide, you’ll be able to set up subscription bundles that process correctly at checkout and integrate smoothly with your subscription app.

The cart-level bundle expansion workaround described in this article is not compatible with standard ReCharge installations.

ReCharge creates a unique selling_plan ID per variant for every subscription cadence. Because of this, copying the parent bundle's selling_plan ID to the child variants will result in a HTTP 422 – "Cannot apply selling plan to variant" error from Shopify, as the child variants are not enrolled in the parent's specific plan ID.

Additionally, since ReCharge expresses discounts as a percentage off each variant's own list price, expanding a bundle into its children at the cart level will produce a cart total that does not match the bundle price shown to the customer on the product page.

Recommended approach: Allow the bundle to proceed to checkout as a single parent line item with the parent's selling plan attached. Simple Bundles will break down the order into its component SKUs after the order is placed via order editing. This is the fully supported flow for ReCharge + Simple Bundles 2.0.

How breaking down at the cart level works

When a customer adds a bundle to their cart with a subscription selected, the script performs the following actions:

Detects that the product is a bundle and includes a selling plan
Reads the bundle’s component data from metafields
Expands the bundle into its individual child products
Attaches the selected selling plan to each child product
Adds the child products to the cart instead of the parent bundle
Redirects the customer to the cart page

This script activates only when both conditions are met:

The product is a bundle (has bundle metafields)
A selling plan (subscription) is selected
Child products must be enrolled in the same selling plans as the bundle parent

Non-subscription bundle purchases continue to work normally, with Cart Transform handling the breakdown at checkout. One-time bundle purchases follow the standard Simple Bundles flow without any changes. Regular (non-bundle) products are completely unaffected and will continue to function as usual.

Supported bundle types

This solution works with:

Simple Bundles (predefined child products)
Infinite Options Bundles (customer-selected options)

How to break down the bundle at the cart level

To implement this solution, please follow the steps below.

Step 1: Download the required files

Before getting started, download the following files provided with this guide:

Make sure these files are saved locally so they can be uploaded to your Shopify theme.

Step 2: Upload the files to your theme

In your Shopify admin, go to Online Store > Themes.
Click Edit code on your active theme.

Then upload the files to the correct locations:

Add simple-bundles-metafields.liquid to your Snippets folder.
Add simple-bundles-cart-expander.js to your Assets folder.

Uploading the file in online store theme snippets folder

Uploading the file in the online store theme assets folder

Step 3: Include the files in your theme

After uploading both files, you’ll need to include them in your theme so they load properly.

In layout/theme.liquid (recommended) or within your product template file, add the following code just before the closing </body> tag:

{% render 'simple-bundles-metafields' %} {{ 'simple-bundles-cart-expander.js' | asset_url | script_tag }}

This ensures the bundle metafield data is available and the cart expander script runs correctly when a subscription bundle is added to the cart.

Once added, save your changes and test a subscription bundle to confirm it expands properly before checkout.

Cart and order display overview

Bundle display in the product detail page

Bundle will be broken down in cart instead of the checkout

Order with the bundle broken down at the cart level

Troubleshooting

Bundle Not Expanding

If the bundle is not expanding, verify that the variant has bundle metafields by running SBExpanderDebug.checkVariant('VARIANT_ID') in your browser console. Check that the Liquid snippet is rendering correctly on the page and confirm that a selling plan (subscription) is selected before adding the bundle to the cart.

Child Products Not Being Added

Ensure that the child products are enrolled in the same selling plans as the bundle. You can also check your browser’s Network tab and review the add.js response for any errors when the product is added to cart.

Cart Not Updating or No Redirect

Different themes handle cart updates differently. The current script redirects customers to /cart after adding the expanded items. If your theme uses a cart drawer or custom cart behavior, the script may need to be adjusted to match your theme’s setup.

Support

If you encounter any issues or need the script customized for your theme, please contact our support team at hello@simplebundles.io.