Cart mutations now return error for invalid merchandise configuration

We have enhanced error handling for cart mutations to provide clearer feedback when merchandise cannot be added to or maintained in a cart. The cart API now returns a MERCHANDISE_NOT_APPLICABLE error code for specific merchandise-related issues.

When This Error Occurs

The MERCHANDISE_NOT_APPLICABLE error is triggered in the following scenarios:

Inventory & Availability Issues:

• The item is out of stock or insufficient stock is available for the requested quantity.
• The product is not published or is unavailable in the buyer's location.
• The inventory record is missing.
• The product variant does not exist.

Pricing & Configuration Issues:

• There is a discrepancy between expected and actual prices.
• Gift cards have zero or invalid amounts.
• Bundle products lack required components.
• The cart line item limit is exceeded.

What This Means for Your Integration

If you receive a MERCHANDISE_NOT_APPLICABLE error:

• The specified merchandise cannot be added to the cart in its current configuration.
• Notify customers about the availability issue.
• Refresh product data or adjust quantities as needed.
• For bundles, ensure all required components are present.