Shopify Admin Metafield Bulk Update

Purpose

Queries products (or variants, or customers) matching a filter and bulk-sets or bulk-deletes metafield values. Used for structured data updates like material composition, care instructions, product specifications, or custom attributes that power storefront features.

Prerequisites

• Authenticated Shopify CLI session: shopify store auth --store <domain> --scopes read_products,write_products
• API scopes: read_products, write_products
• Metafield namespace and key must already exist or be created on first set

Parameters

Safety

⚠️ metafieldsSet overwrites existing metafield values — there is no merge. metafieldsDelete permanently removes the metafield value from the resource. Run with dry_run: true to confirm the affected product list and verify namespace/key are correct before committing.

Workflow Steps

1. OPERATION: products — query Inputs: query: <filter>, first: 250, select metafield values for the target namespace/key, pagination cursor Expected output: Products with existing metafield values (for reference); paginate until hasNextPage: false

2. OPERATION: metafieldsSet — mutation (if action: set) Inputs: Array of { ownerId, namespace, key, value, type } objects Expected output: metafields { id, key, value }, userErrors

3. OPERATION: metafieldsDelete — mutation (if action: delete) Inputs: Array of { ownerId, namespace, key } objects Expected output: deletedMetafields { ownerId }, userErrors

GraphQL Operations

# products:query — validated against api_version 2025-01
query ProductsWithMetafield($query: String!, $namespace: String!, $key: String!, $after: String) {
  products(first: 250, after: $after, query: $query) {
    edges {
      node {
        id
        title
        metafield(namespace: $namespace, key: $key) {
          id
          value
          type
        }
      }
    }
    pageInfo {
      hasNextPage
      endCursor
    }
  }
}

# metafieldsSet:mutation — validated against api_version 2025-01
mutation MetafieldsSet($metafields: [MetafieldsSetInput!]!) {
  metafieldsSet(metafields: $metafields) {
    metafields {
      id
      namespace
      key
      value
      type
      owner {
        ... on Product {
          id
          title
        }
      }
    }
    userErrors {
      field
      message
      code
    }
  }
}

# metafieldsDelete:mutation — validated against api_version 2025-01
mutation MetafieldsDelete($metafields: [MetafieldIdentifierInput!]!) {
  metafieldsDelete(metafields: $metafields) {
    deletedMetafields {
      ownerId
      namespace
      key
    }
    userErrors {
      field
      message
    }
  }
}

Session Tracking

Claude MUST emit the following output at each stage. This is mandatory.

On start, emit:

╔══════════════════════════════════════════════╗
║  SKILL: Metafield Bulk Update                ║
║  Store: <store domain>                       ║
║  Started: <YYYY-MM-DD HH:MM UTC>             ║
╚══════════════════════════════════════════════╝

After each step, emit:

[N/TOTAL] <QUERY|MUTATION>  <OperationName>
          → Params: <brief summary of key inputs>
          → Result: <count or outcome>

If dry_run: true, prefix every mutation step with [DRY RUN] and do not execute it.

On completion, emit:

For format: human (default):

══════════════════════════════════════════════
OUTCOME SUMMARY
  Resources matched:      <n>
  Metafields set/deleted: <n>
  Errors:                 <n>
  Output:                 metafield_update_<date>.csv
══════════════════════════════════════════════

For format: json, emit:

{
  "skill": "metafield-bulk-update",
  "store": "<domain>",
  "started_at": "<ISO8601>",
  "completed_at": "<ISO8601>",
  "dry_run": true,
  "namespace": "<ns>",
  "key": "<key>",
  "action": "set",
  "outcome": {
    "matched": 0,
    "updated": 0,
    "errors": 0,
    "output_file": "metafield_update_<date>.csv"
  }
}

Output Format

CSV file metafield_update_<YYYY-MM-DD>.csv with columns: resource_type, resource_id, title, namespace, key, old_value, new_value, action

Error Handling

Best Practices

• metafieldsSet is batched — the mutation accepts up to 25 metafields per call. The skill automatically batches large product sets.
• Always verify the namespace and key match your store's metafield definitions — typos create orphaned metafields that don't connect to any theme feature.
• For storefront-powered metafields (e.g., displayed in product templates), confirm the theme reads the correct namespace/key before running at scale.
• Use dry_run: true to preview exactly which products and current values will be affected before overwriting.