The customer must reach Shopify checkout with one valid Shopify variant and the matching Composerie design. Embedded publications can either keep the theme’s variant controls or let Composerie replace them.
Replace variant UI lives in the publication’s Appearance settings, alongside the other four overrides. Turn it on only when Composerie should own product-option selection on the page, and never leave the theme’s own picker in place beside it.
Check what actually goes to Shopify
The Publish screen counts the variants that will travel with the publication, under This goes to Shopify. Expand them and read the list: a variant that is not in it cannot be bought, whatever the storefront shows.

Choose one variant authority
Review the embedded display controls in the product’s store settings. Use variant replacement only when Composerie’s controls should own selection. The first Publish screen uses mode defaults and does not include the earlier Configure step.
Do not leave two active sets of selectors. Duplicate variant controls can show one option while Shopify adds another variant to the cart.
Test the full handoff
Before publishing broadly:
- select every available option combination;
- confirm hidden or unavailable variants cannot be chosen;
- check that the displayed price follows the selected variant and add-ons;
- complete required personalization;
- add the item to cart and finish one test checkout;
- open the Composerie order and compare its variant, add-ons, and proof.
Should Composerie replace my theme's variant UI?
Only when you want Composerie's embedded controls to be the single selector. Otherwise leave the theme controls in charge.
How do I know the correct variant reached the order?
Compare the order line's variant and add-ons with the customer proof after a test checkout.
What if a variant is sold out?
The owning UI must prevent selection and Shopify remains the final inventory authority at checkout.
Next
See how a personalized design reaches the order for the saved-design binding.