Shopify Apps on Checkout
Last updated on October 21, 2026
Shopify doesn't let apps add their own scripts to the checkout page. Apps can only change checkout through Shopify's own tools, Shopify Functions and checkout extensions, and Vitals uses them:
- Upsell Builder discounts are applied at checkout as Shopify automatic discounts. See Understanding How Vitals Upsell Offers Now Work with Shopify Functions.
- Thank you and order status pages can show Upsell Builder offers. See Enabling Thank You Page Upsells.
- EU Legal Guarantee: on Shopify Plus, you can add its blocks in the checkout editor.
Other Vitals apps, such as Sticky Add to Cart or Product Reviews, don't show on the checkout page.