Build a field set
Choose field types, property names, validation, variants, and appearance.
Open builderDocumentation
From field idea to tested order.
Short, practical guides for building, installing, and verifying Shopify line-item property fields.
Install the code
Add one Custom Liquid block to the correct Product information section.
Installation guideTest the result
Verify both purchase paths, the cart payload, variants, and the order.
Testing checklistThe important Shopify concept
Every generated control uses a name such as properties[Engraving]. Shopify attaches that name and value to the purchased line item. Cart Field Studio does not use metafields, alter product prices, or send the value to its own servers.
Why a runtime bridge exists
A Custom Liquid block can sit outside the product form. The generated bridge identifies the appropriate product form, uses the HTML form attribute, creates a descendant fallback for themes that serialize only form children, and normalizes the final FormData payload.