Update product metafield with metaobject entry through Shopify flow

Topic summary

The discussion centers on updating product metafields that reference metaobject entries using Shopify Flow, specifically when new products are added.

Initial Challenge:

  • User wanted to automatically assign different metaobject entries to products based on product type (e.g., Entry A for Type A, Entry B for Type B)
  • No clear way to select specific metaobject entries in Flow’s interface

Solution for Single Metaobject References:
For small product sets, the “Update product metafield” action works by:

  • Setting type to “Metaobject”
  • Entering the GID directly in value field: gid://shopify/Metaobject/123
  • Finding the ID in the metaobject entry’s URL
  • Avoiding spaces/newlines in the value

Solution for List of Metaobjects:
A more complex scenario emerged involving metafields containing lists of metaobjects (like materials). The working solution requires:

  • Using the “Run Code” action to generate an array of GIDs
  • Converting the set to JSON string format: ["gid://shopify/Metaobject/123","gid://shopify/Metaobject/456"]
  • Passing this output to “Update product metafield” action

Status: Resolved with working examples and code snippets provided for both scenarios. Community members confirmed solutions worked and shared helpful GitHub resources for Flow code examples.

Summarized with AI on October 27. AI used: claude-sonnet-4-5-20250929.

Is this a small set of products or a lot of products?