{
  "id": "gtin.feeds",
  "protocol": "gtin",
  "layer": "product-data",
  "role": "merchant",
  "status": "recommended",
  "title": "Provide GTINs in every feed where assigned",
  "description": "Google: recommended for all products with a manufacturer-assigned GTIN ('It depends, strongly recommended if available' in the spec); accurate matching can't be assured when GTIN is missing, and a product with an assigned GTIN that you don't submit could be disapproved. Microsoft: required if assigned. OpenAI: optional, do not invent an mpn.",
  "goal": "GTIN is how agents match the same product across merchants, feeds and markup.",
  "note": "Re-verified 2026-10-12 against Google's GTIN page. Don't submit a GTIN for products without one (store brands, custom items); use brand and mpn instead. Each variant needs its own GTIN. Ideally provide GTIN together with MPN.",
  "how_to_implement": {
    "steps": [
      "Store manufacturer GTINs in your PIM.",
      "Export them to every feed and to on-page markup."
    ]
  },
  "resources": [
    {
      "label": "Google Merchant Center: GTIN",
      "url": "https://support.google.com/merchants/answer/6324461",
      "type": "docs",
      "publisher": "Google"
    },
    {
      "label": "Microsoft Merchant Center catalog file",
      "url": "https://learn.microsoft.com/en-us/advertising/msa-help/hlp_ba_conc_aboutbingmerchantcentercatalogfile",
      "type": "docs",
      "publisher": "Microsoft"
    },
    {
      "label": "OpenAI product feed spec",
      "url": "https://developers.openai.com/commerce/specs/file-upload/products",
      "type": "spec",
      "publisher": "OpenAI"
    }
  ],
  "audit": {
    "method": "feed_check",
    "automatable": true,
    "expect": {
      "field_present": "gtin",
      "when": "manufacturer assigned"
    },
    "human": "Merchant Center reports no missing or invalid GTIN issues."
  },
  "how_to_verify": "Merchant Center reports no missing or invalid GTIN issues.",
  "artifacts": [
    "gtin"
  ],
  "depends_on": [],
  "status_note": "Re-verified 2026-10-12 against Google's GTIN page. Don't submit a GTIN for products without one (store brands, custom items); use brand and mpn instead. Each variant needs its own GTIN. Ideally provide GTIN together with MPN.",
  "verified": true,
  "status_rationale": "Microsoft requires GTIN when assigned; Google strongly recommends it and may disapprove products missing an assigned GTIN; OpenAI marks it optional.",
  "slug": "gtin-feeds",
  "category": "product-data",
  "url": "https://vreeman.ai/commerce/checklist#gtin.feeds",
  "updated": "2026-10-12",
  "sources": [
    {
      "label": "Google Merchant Center: GTIN",
      "url": "https://support.google.com/merchants/answer/6324461",
      "type": "docs",
      "publisher": "Google"
    },
    {
      "label": "Microsoft Merchant Center catalog file",
      "url": "https://learn.microsoft.com/en-us/advertising/msa-help/hlp_ba_conc_aboutbingmerchantcentercatalogfile",
      "type": "docs",
      "publisher": "Microsoft"
    },
    {
      "label": "OpenAI product feed spec",
      "url": "https://developers.openai.com/commerce/specs/file-upload/products",
      "type": "spec",
      "publisher": "OpenAI"
    }
  ],
  "related_slugs": []
}