How to use "CartTransform - Merge" feature on my shopify Basic / Shopify plan

Retired Boards Appdev Extensions

Topic summary

A developer wants to create a bundle feature that merges two cart line items into one with a customized image. Their research indicates:

Key Findings:

  • The “CartTransform - Merge” feature can accomplish this goal
  • Implementation requires building an “extension-only app” (no direct implementation available)
  • Extension-only apps cannot be distributed to the Shopify App Store
  • Only Shopify Plus plans can use this functionality

The Problem:
The developer is on a Basic/Shopify plan (not Plus), which means they cannot use their custom app even if they build it.

Seeking Confirmation:
Asking whether their understanding is correct—that there’s no way to achieve their goals (merge line items, change bundled item image to custom image, maintain current plan) without upgrading to Shopify Plus.

Summarized with AI on November 7. AI used: claude-sonnet-4-5-20250929.
1

HI There,

I want to implement the bundle feature, which can combine two products into one lineitem with “customized image”

I do some research, and listed the finding below.

  1. “CartTransform - Merge” feature can achieve my goals

  2. I can “only” build the “extension-only app” to implement the “CartTransform - Merge” feature. There is no other way to implement ShopifyFunctions on my store directly.

  3. I can distribute my “extension-only app” to be a custom app, but only “Plus Plan Store” can use it.

  4. I cannot distribute my “extension-only app” to Shopify App Store, so I have no way to use my app on my store.

So based on above, is this no any chance to achieve my goal. is it correct?

Or do I have any other chance to do:

  • merge any two cart line items into one line item.

  • change the bundled line item image to be a customized image.

  • keep the store plan as Shopify plan or Basic plan.

Thanks for your help.