# Fetching carrier-calculated rates through `@defer` directive in Storefront GraphQL API — Shopify developer changelog
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## Fetching carrier-calculated rates through `@defer` directive in Storefront GraphQL API

As of `2024-07`, `Cart#deliveryGroups` supports a new `withCarrierRates` argument, used to indicate intent to fetch carrier-calculated rates. This capability requires mandatory use of `@defer` directive, which ensures that the cart response is not blocked on calculating rates.

Test out the carrier-calculated rates on the cart today by [following our tutorial](https://shopify.dev/docs/custom-storefronts/building-with-the-storefront-api/defer#fetching-carrier-calculated-rates-for-the-cart-using-defer). We value your input, please share your [feedback on Github.](https://github.com/Shopify/storefront-api-feedback/discussions/234)

*Published: July 01, 2024*
Tags: API, New
Link: https://shopify.dev/changelog/fetching-carrier-calculated-rates-through-defer-directive-in-storefront-graphql-api

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