---
title: cartMetafieldsSet - Storefront API
description: |
  Sets cart metafield values. Cart metafield values will be set regardless if they were previously created or not.

  Allows a maximum of 25 cart metafields to be set at a time.
api_version: 2025-10
api_name: storefront
type: mutation
api_type: graphql
source_url:
  html: https://shopify.dev/docs/api/storefront/latest/mutations/cartMetafieldsSet
  md: https://shopify.dev/docs/api/storefront/latest/mutations/cartMetafieldsSet.md
---

# cart​Metafields​Set

mutation

Sets cart metafield values. Cart metafield values will be set regardless if they were previously created or not.

Allows a maximum of 25 cart metafields to be set at a time.

## Arguments

* metafields

  [\[Cart​Metafields​Set​Input!\]!](https://shopify.dev/docs/api/storefront/latest/input-objects/CartMetafieldsSetInput)

  required

  The list of Cart metafield values to set. Maximum of 25.

  The input must not contain more than `250` values.

***

## Cart​Metafields​Set​Payload returns

* metafields

  [\[Metafield!\]](https://shopify.dev/docs/api/storefront/latest/objects/Metafield)

  The list of cart metafields that were set.

* user​Errors

  [\[Metafields​Set​User​Error!\]!](https://shopify.dev/docs/api/storefront/latest/objects/MetafieldsSetUserError)

  non-null

  The list of errors that occurred from executing the mutation.

***

## Examples

* ### cartMetafieldsSet reference

## Mutation Reference

```graphql
mutation cartMetafieldsSet($metafields: [CartMetafieldsSetInput!]!) {
  cartMetafieldsSet(metafields: $metafields) {
    metafields {
      # Metafield fields
    }
    userErrors {
      field
      message
    }
  }
}
```

## Input

##### Variables

```json
{
  "metafields": [
    {
      "ownerId": "gid://shopify/<objectName>/10079785100",
      "key": "<your-key>",
      "value": "<your-value>",
      "type": "<your-type>"
    }
  ]
}
```

##### Schema

```graphql
input CartMetafieldsSetInput {
  ownerId: ID!
  key: String!
  value: String!
  type: String!
}
```