Overview of the Update
As part of the GraphQL Storefront API 2026-01 release, Shopify has updated the cartDiscountCodesUpdate mutation. It now requires the discountCodes argument to be included in your API calls. This change ensures that interactions with the Cart object are intentional and meaningful.
What Changed?
Previously, the cartDiscountCodesUpdate mutation allowed API calls that omitted the discountCodes argument. However, these requests would not actually modify the cart, leading to potential confusion for developers. With the latest release, providing the discountCodes field is mandatory.
How This Impacts Your Work
If your apps or integrations currently use the cartDiscountCodesUpdate mutation, review your requests to ensure they include the discountCodes argument. This will avoid errors and ensure expected functionality in your applications.
Learn More
To better understand the Cart object and its related mutations, visit the official Shopify developer documentation. Staying updated with API changes ensures your apps remain compliant and functional.