---
title: CartMetafieldsSetInput - Storefront API
description: The input fields for a cart metafield value to set.
api_version: 2025-07
api_name: storefront
type: input-object
api_type: graphql
source_url:
  html: >-
    https://shopify.dev/docs/api/storefront/2025-07/input-objects/CartMetafieldsSetInput
  md: >-
    https://shopify.dev/docs/api/storefront/2025-07/input-objects/CartMetafieldsSetInput.md
---

# Cart​Metafields​Set​Input

input\_object

The input fields for a cart metafield value to set.

## Fields

* key

  [String!](https://shopify.dev/docs/api/storefront/2025-07/scalars/String)

  non-null

  The key name of the cart metafield.

* owner​Id

  [ID!](https://shopify.dev/docs/api/storefront/2025-07/scalars/ID)

  non-null

  The ID of the cart resource.

* type

  [String!](https://shopify.dev/docs/api/storefront/2025-07/scalars/String)

  non-null

  The type of data that the cart metafield stores. The type of data must be a [supported type](https://shopify.dev/apps/metafields/types).

* value

  [String!](https://shopify.dev/docs/api/storefront/2025-07/scalars/String)

  non-null

  The data to store in the cart metafield. The data is always stored as a string, regardless of the metafield's type.

***

## Map

No referencing types