Apply a Coupon

GraphQL counterpart of POST /api/admin/carts/{id}/coupon. Mutation field is applyCouponAdminCart.

Select cart fields, not id

This mutation returns the updated cart — select itemsCount, grandTotal, formattedGrandTotal, success, message, etc. Do not select id (or _id): this is an action result with no addressable record, so the auto-generated IRI field is null and selecting it errors out the whole payload.

Prerequisites

The example uses an illustrative cart id. Admin cart endpoints only operate on draft carts (is_active=0) — storefront carts are rejected by the admin cart guard. Create a draft cart first with the createAdminDraftCart mutation and use the returned cartId.

Operation

Operation	Type
applyCouponAdminCart(input: applyCouponAdminCartInput!)	Mutation