productVariant query with variant id "Required parameter missing or invalid"

Technical Q&A

Topic summary

A developer encountered a “Required parameter missing or invalid” error when executing a Shopify productVariant GraphQL query in PHP, despite the same query working successfully in Postman.

Initial Problem:

  • The query requested product variant data including price, SKU, and component information
  • Same cURL implementation worked for other queries/mutations in the application
  • Authentication and headers (content-type) were properly configured

Resolution:
The issue was resolved independently—it was a formatting error in the GraphQL query syntax. The query was missing the query keyword before the operation name, which caused the cryptic error message.

Key Takeaway:
The developer noted that more detailed error messages would have helped identify this syntax issue faster.

Summarized with AI on October 24. AI used: claude-sonnet-4-5-20250929.
1

Hello,

I was able to successfully run this in Postman, but in PHP, it is claiming I am missing a required parameter. Only the id is required, so what gives??

query productVariant {
    productVariant(id: "gid://shopify/ProductVariant/51370387439897") {
        id
        price
        sku
        productVariantComponents(first: 10) {
            nodes {
                id
                quantity
                productVariant {
                    displayName
                    id
                    price
                    sku
                    storefrontId
                    taxable
                }
            }
        }
    }
}

I have also tried using nodes which everybody else seems to have success with, and I get the same response! it also works fine in Postman but not in my php code.

The same cURL code that I am running here is running elsewhere in my app, with success with many queries and mutations, so I was surprised to run into this issue. I am definitely setting content-type and all that.

Any thoughts? thank you!!

2

@jillianctg can you provide a screenshot of the stack trace from your PHP app claiming you’re missing a required parameter?

If you are able to run the query identically in Postman, but it’s failing out in your app I wonder if your API auth token isn’t being set properly when you call Shopify from the PHP side.

3

Thanks for your response. Let me know if this isn’t what you are asking for.

Screenshot 2025-10-06 at 21.11.59
Screenshot 2025-10-06 at 21.11.591592×1438 293 KB

5

You know what, nevermind. I just figured it out. I just wish the error messages were a little more thorough, I was just missing a “query” before the titled query and it didn’t like that formatting mistake.