Variant Guard scans product variants for missing or duplicate SKUs and barcodes, invalid GTIN checksums, non-standard barcode formats, and zero prices. Filter affected variants and open the source product in Shopify. When a SKU is missing, create a deterministic fix preview before applying any change. Existing SKUs are never replaced by that workflow, and catalog edits made after preview are skipped as conflicts. The app does not generate or certify barcodes.

• Scan for missing or duplicate SKUs and barcodes
• Validate GTIN checksums and flag zero prices
• Filter affected variants and open products in Shopify
• Generate missing SKUs from deterministic templates
• Preview every SKU change and skip rows changed after preview