Using Bundlex with cart replacement apps (UpCart and similar)

Cart replacement apps rebuild your store's add to cart flow with their own code. Examples include UpCart, MonsterCart, product option apps that submit the cart themselves, and some cash on delivery checkout apps. When one of these controls the add to cart button, the data Bundlex attaches to each cart line can be stripped away, and the bundle discount doesn't come through.

Why this happens

When a customer adds a bundle, Bundlex tags every line with small hidden properties that tell the discount which offer the items belong to. A cart app that intercepts the button and rebuilds the request from scratch usually copies only the product and quantity, not the hidden properties. The items land in the cart, but to the discount they look like ordinary products, so no bundle price is applied.

This isn't specific to Bundlex. Any app that relies on cart line properties, including many upsell and bundle apps, loses data the same way when another app rewrites the add to cart request.

What you can do

There is no reliable fix from the Bundlex side while both apps fight over the same button, but you have options:

Disable the cart app on products that have bundle offers, so the standard add to cart flow runs there.

Ask the cart app's support whether their add to cart can preserve custom line item properties. Some apps have a setting or can enable it for your store.

If you mainly use the cart app for a slide-out cart drawer, check whether your theme has a built-in drawer. Theme drawers work with Bundlex out of the box, see using Bundlex with cart drawers.

Not sure which app is interfering?

Contact us in the app chat with a link to the product page. We can usually identify the conflicting app from the storefront in a few minutes.