productVariantsBulkUpdate upload image fror variations

Technical Q&A

Topic summary

A developer is encountering an intermittent error when assigning images to product variants using Shopify’s GraphQL API during product migration.

Workflow:

  • Creates products using ProductSet mutation with all product images
  • Uses productVariantsBulkUpdate to assign specific images to variants by referencing image IDs from the first mutation

Error encountered:

"MUST_BE_FOR_THIS_PRODUCT" - "Image must be for this product"

Key observations:

  • Error occurs specifically on variant field 5 (and potentially others)
  • Happens when importing the same product with identical options and images multiple times in quick succession
  • Re-running the mutation typically resolves the error
  • The developer is reusing media IDs created during ProductSet for the bulk variant update

Current status:
The issue appears to be a timing or synchronization problem with the API, but no resolution has been identified. The discussion includes code examples of both mutations being used.

Summarized with AI on November 4. AI used: claude-sonnet-4-5-20250929.
1

This is the flow that I follow in order to create a product in my Shopify account:

  • I use GraphQL API;

  • The first thing that I do is to use the “ProductSet” Mutation in order to create the Product and send all the images referred to the product;

  • Then I use the “productVariantsBulkUpdate” to pass the images for the variations, but in order to do it I re-use the imageID created with the “ProductSet” Mutation;

  • When I do this it can happen that I receive the following error for some variations:

      {
        "code": "MUST_BE_FOR_THIS_PRODUCT",
        "field": [
          "variants",
          "5",
          "mediaId"
        ],
        "message": "Image must be for this product"
      }

Also I’ve noticed that this error happens when I try to import the same product with same options and images more than one time in a short time.

If I repeat again the mutation the error doesn’t appear.

Following the two mutations as examples:

ProductSet Mutation:

mutation CreateProductSynchronous($productSet: ProductSetInput!, $synchronous: Boolean!){                       
    productSet(input: $productSet, synchronous: $synchronous) {
        product {
            id
            title
            options {
                id
                name
                optionValues {
                    id
                    name
                }
            }
            media(first:250){
                edges{
                    node{
                        id
                        alt
                        preview{
                            image{
                                id
                                url
                            }
                        }
                    }
                }
            }
            variants(first: 100) {
                edges {
                    node {
                        id
                        title
                        price
                        sku
                    }
                }
            }
        }
        userErrors {
            field
            message
        }
    }
}

variables...

productVariantsBulkUpdate Mutation:

mutation productVariantsBulkUpdate($productId: ID!, $variants: [ProductVariantsBulkInput!]!) {
  productVariantsBulkUpdate(productId: $productId, variants: $variants) {
    product {
      id 
    }
    productVariants {
      id
      media(first:1) {
        edges {
          node {
            id
          }
        }
      }
    }
    userErrors {
      code
      field
      message
      }
    }
  }

"""variables"": {
""productId"": ""gid://shopify/Product/8837826937090"",
""variants"": [
{
""id"": ""gid://shopify/ProductVariant/45598512513282"",
""inventoryPolicy"": ""DENY"",
""inventoryItem"": {
""requiresShipping"": true,
""tracked"": true,
""sku"": ""ZAK-45598512513282""
},
""mediaId"": ""gid://shopify/MediaImage/34440417673474"",
""price"": 17.0,
""taxable"": true
},
{
""id"": ""gid://shopify/ProductVariant/45598512546050"",
""inventoryPolicy"": ""DENY"",
""inventoryItem"": {
""requiresShipping"": true,
""tracked"": true,
""sku"": ""ZAK-45598512546050""
},
""mediaId"": ""gid://shopify/MediaImage/34440417771778"",
""price"": 17.0,
""taxable"": true
},
{
""id"": ""gid://shopify/ProductVariant/45598512578818"",
""inventoryPolicy"": ""DENY"",
""inventoryItem"": {
""requiresShipping"": true,
""tracked"": true,
""sku"": ""ZAK-45598512578818""
},
""mediaId"": ""gid://shopify/MediaImage/34440417870082"",
""price"": 17.0,
""taxable"": true
},
{
""id"": ""gid://shopify/ProductVariant/45598512611586"",
""inventoryPolicy"": ""DENY"",
""inventoryItem"": {
""requiresShipping"": true,
""tracked"": true,
""sku"": ""ZAK-45598512611586""
},
""mediaId"": ""gid://shopify/MediaImage/34440417706242"",
""price"": 17.0,
""taxable"": true
},
{
""id"": ""gid://shopify/ProductVariant/45598512644354"",
""inventoryPolicy"": ""DENY"",
""inventoryItem"": {
""requiresShipping"": true,
""tracked"": true,
""sku"": ""ZAK-45598512644354""
},
""mediaId"": ""gid://shopify/MediaImage/34440417804546"",
""price"": 17.5,
""taxable"": true
},
{
""id"": ""gid://shopify/ProductVariant/45598512677122"",
""inventoryPolicy"": ""DENY"",
""inventoryItem"": {
""requiresShipping"": true,
""tracked"": true,
""sku"": ""ZAK-45598512677122""
},
""mediaId"": ""gid://shopify/MediaImage/34440417902850"",
""price"": 17.0,
""taxable"": true
},
{
""id"": ""gid://shopify/ProductVariant/45598512709890"",
""inventoryPolicy"": ""DENY"",
""inventoryItem"": {
""requiresShipping"": true,
""tracked"": true,
""sku"": ""ZAK-45598512709890""
},
""mediaId"": ""gid://shopify/MediaImage/34440417739010"",
""price"": 17.0,
""taxable"": true
},
{
""id"": ""gid://shopify/ProductVariant/45598512742658"",
""inventoryPolicy"": ""DENY"",
""inventoryItem"": {
""requiresShipping"": true,
""tracked"": true,
""sku"": ""ZAK-45598512742658""
},
""mediaId"": ""gid://shopify/MediaImage/34440417837314"",
""price"": 17.0,
""taxable"": true
},
{
""id"": ""gid://shopify/ProductVariant/45598512775426"",
""inventoryPolicy"": ""DENY"",
""inventoryItem"": {
""requiresShipping"": true,
""tracked"": true,
""sku"": ""ZAK-45598512775426""
},
""mediaId"": ""gid://shopify/MediaImage/34440417935618"",
""price"": 17.0,
""taxable"": true
}
]
}"

Response:

"""productVariantsBulkUpdate"": {
  ""product"": {
    ""id"": ""gid://shopify/Product/8837826937090""
  },
  ""productVariants"": [
    {
      ""id"": ""gid://shopify/ProductVariant/45598512513282"",
      ""media"": {
        ""edges"": []
      }
    },
    {
      ""id"": ""gid://shopify/ProductVariant/45598512546050"",
      ""media"": {
        ""edges"": []
      }
    },
    {
      ""id"": ""gid://shopify/ProductVariant/45598512578818"",
      ""media"": {
        ""edges"": []
      }
    },
    {
      ""id"": ""gid://shopify/ProductVariant/45598512611586"",
      ""media"": {
        ""edges"": []
      }
    },
    {
      ""id"": ""gid://shopify/ProductVariant/45598512644354"",
      ""media"": {
        ""edges"": []
      }
    },
    {
      ""id"": ""gid://shopify/ProductVariant/45598512677122"",
      ""media"": {
        ""edges"": []
      }
    },
    {
      ""id"": ""gid://shopify/ProductVariant/45598512709890"",
      ""media"": {
        ""edges"": []
      }
    },
    {
      ""id"": ""gid://shopify/ProductVariant/45598512742658"",
      ""media"": {
        ""edges"": []
      }
    },
    {
      ""id"": ""gid://shopify/ProductVariant/45598512775426"",
      ""media"": {
        ""edges"": []
      }
    }
  ],
  <strong>""userErrors"": [
  {
    ""code"": ""MUST_BE_FOR_THIS_PRODUCT"",
    ""field"": [
      ""variants"",
      ""0"",
      ""mediaId""
    ],
    ""message"": ""Image must be for this product""
  },
  {
    ""code"": ""MUST_BE_FOR_THIS_PRODUCT"",
    ""field"": [
      ""variants"",
      ""5"",
      ""mediaId""
    ],
    ""message"": ""Image must be for this product""
  }
 ]</strong>
}"

As you can see I can receive the error: MUST_BE_FOR_THIS_PRODUCT

How can I resolve this error?