Cart Transform image not being persisted

[adamshogun]

Hello,

We at Shogun are building out a feature involving the use of the Cart Transform Function API to change the title and image of line items, and are encountering an issue that appears to be on Shopify’s end.

Our function conditionally changes the title and image of a line item in the cart using the lineUpdate operation, but there appears to be inconsistency in what is being persisted. The updated title does successfully persist everywhere – cart, checkout, and order. The image, however, is only being changed within checkout itself – the cart and resulting order still show the incorrect (original) image.

Cart:

Checkout:

Order:

Looking at the cart object, I can see the title is persisting the altered version, but the image is still referencing the original image:

The original image URL is https://cdn.shopify.com/s/files/1/0742/8305/7468/files/preview_images/d5ff1265f33e427cba75cc27b5e1e2f5.thumbnail.0000000000.jpg?v=1769110695, while the updated and expected URL is https://cdn.shopify.com/s/files/1/0742/8305/7468/products/2406ea4db27c3e7bbc7f77d9d6ce1fa8_c804bade-fa55-4a83-8917-1cfcd65ae269.jpg?v=1698768857.

Looking at the logs for the cart transform function, I can confirm it is returning the correct image URL:

Output (277 bytes):

     {
       "operations": [
         {
           "update": {
             "cartLineId": "gid://shopify/CartLine/9a50aad9-ec20-4b2c-af72-66f84fc1ae43",
             "image": {
               "url": "https://cdn.shopify.com/s/files/1/0742/8305/7468/products/2406ea4db27c3e7bbc7f77d9d6ce1fa8_c804bade-fa55-4a83-8917-1cfcd65ae269.jpg?v=1698768857"
             },
             "price": null,
             "title": "The BEST Tee"
           }
         }
       ]
     }

I am testing this on a Plus Partner Sandbox shop, and have confirmed that in my theme liquid that it uses the line item’s title/price, and that it’s not pulling this data from the product/variant.

From everything I can find on the documentation, this should be working. At this point, it suggests the issue being on Shopify’s end. Any help in getting to the bottom of this and resolving the issue would be greatly appreciated.

Let me know if I can provide anything else to be of help.

Thank you,

Adam

[Liam-Shopify]

Hey @adamshogun

Thanks for flagging this - I’m digging into this on my side. In the meantime one thing you could check is that the API version being used is correct and matches the expected configuration?

[adamshogun]

Hey @Liam-Shopify, thanks for taking a look into this.

This function was built using API version 2025-07 (it has existed in production for a couple months now without this new functionality), and I’ve confirmed through the API documentation of this version that manipulating the image is supported. I had also attempted to use the latest version (2026-01) to see if that resolved the issue, but it did not make any difference.

[Liam-Shopify]

Hi again @adamshogun

From digging into this, it does look like this is a known limitation with cart transform functions. The team are aware of this limitation but there’s no ETA I can share for when this will be addressed - I’m looking into updating the developer docs so this limitation is clear.

[Liam-Shopify]

Hi again @adamshogun

We’ve updated the docs to highlight the limitation that you’ve experienced:

[adamshogun]

Hi Liam,

Thanks for the update, although updating the documentation doesn’t really help our situation. Please let me know when the actual underlying issue get fixed.

I see only the docs for the expand operation were updated, do the other operations have the same limitation?

• Cart Transform Function API
• Cart Transform Function API

However the section specific to image and title transformations still states that the overrides apply everywhere: Cart Transform Function API

Thanks,

Adam