shopify-admin-duplicate-sku-barcode-detector

Purpose

Scans all product variants and identifies duplicate SKUs or barcodes — two or more variants sharing the same identifier. Duplicate SKUs cause inventory sync failures, incorrect order routing, and accounting mismatches. Read-only — no mutations.

Prerequisites

• Authenticated Shopify CLI session: shopify store auth --store <domain> --scopes read_products
• API scopes: read_products

Parameters

Parameter	Type	Required	Default	Description
store	string	yes	—	Store domain (e.g., mystore.myshopify.com)
check_skus	bool	no	true	Check for duplicate SKUs
check_barcodes	bool	no	true	Check for duplicate barcodes
include_blank	bool	no	false	Flag variants with blank/null SKU
format	string	no	human	Output format: human or json

Safety

ℹ️ Read-only skill — no mutations are executed. Safe to run at any time.

Workflow Steps

1. OPERATION: productVariants — query Inputs: first: 250, select sku, barcode, product { title }, pagination cursor Expected output: All variants with SKU and barcode values; paginate until hasNextPage: false

2. Build in-memory map of sku → [variants] and barcode → [variants]

3. Report all keys with more than one variant (duplicates)

4. If include_blank: additionally flag variants where sku is null or empty string

GraphQL Operations

# productVariants:query — validated against api_version 2025-01
query VariantIdentifiers($after: String) {
  productVariants(first: 250, after: $after) {
    edges {
      node {
        id
        sku
        barcode
        title
        product {
          id
          title
          handle
          status
        }
      }
    }
    pageInfo {
      hasNextPage
      endCursor
    }
  }
}

Session Tracking

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

On start, emit:

╔══════════════════════════════════════════════╗
║  SKILL: Duplicate SKU/Barcode Detector       ║
║  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>

On completion, emit:

For format: human (default):

══════════════════════════════════════════════
DUPLICATE SKU / BARCODE REPORT
  Variants scanned:      <n>
  Duplicate SKUs found:  <n> groups
  Duplicate barcodes:    <n> groups
  Blank SKUs:            <n>

  Duplicate SKU groups:
    SKU "ABC-123"  — used by 2 variants:
      Product A / Blue / L
      Product B / Navy / XL
  Output: duplicates_<date>.csv
══════════════════════════════════════════════

For format: json, emit:

{
  "skill": "duplicate-sku-barcode-detector",
  "store": "<domain>",
  "variants_scanned": 0,
  "duplicate_sku_groups": 0,
  "duplicate_barcode_groups": 0,
  "blank_skus": 0,
  "output_file": "duplicates_<date>.csv"
}

Output Format

CSV file duplicates_<YYYY-MM-DD>.csv with columns: issue_type, duplicate_value, variant_id, product_title, variant_title, sku, barcode

Error Handling

Error	Cause	Recovery
THROTTLED	API rate limit exceeded	Wait 2 seconds, retry up to 3 times
No duplicates found	Clean catalog	Exit with ✅ no issues found

Best Practices

• Run this skill after every bulk product import — imports are the most common source of duplicate SKUs.
• A shared SKU across products is only valid if you intentionally use the same SKU for reprints or variants — most cases are data errors.
• Blank SKUs are not duplicates but can cause problems with 3PLs and fulfillment systems that require a SKU for every variant — use include_blank: true to surface them.
• After identifying duplicates, use the Shopify Admin UI or the productVariantsBulkUpdate mutation to correct SKU values.