Why configured prices must be verified at checkout

Cart attributes can be edited by anyone with a browser console. Here is how Composa keeps prices honest.

Composa team · October 23, 2026 · 2 min read

Many option apps pass the price to checkout in a way shoppers can edit. Composa signs every configured price on its server and checks the signature in a Shopify Cart Transform.

What happens if someone edits the cart

The signature no longer matches, so the line is charged at the product's normal price. You never sell below your configured price.