Signed prices and the Cart Transform

When a shopper adds to cart, Composa recalculates the price on its server and signs it. At checkout, the Composa Cart Transform checks the signature before setting the price.

• Update mode (Shopify Plus and development stores) changes the line price.
• Expand mode (all other plans) expands the line into its own variant at the configured price.

If a store already uses another app's cart transform, Composa switches to a discount-based fallback.