Google Merchant Center for AI Mode and Gemini: what to fill in

Your Merchant Center product data is what Google's AI shopping experiences read. Free listings can appear across Search, Gemini, YouTube, Shopping, Images and Lens, on by default but never guaranteed. Get the required fields right first, then add the attributes Google named for AI Mode, such as question_and_answer and related_product.

Required fields first

Attribute	Rule
`id`	Required; ≤50 characters
`title` / `description`	Required; ≤150 / ≤5,000 characters; must match the landing page, no promo text
`link` / `image_link`	Required; images without watermarks; up to 10 `additional_image_link`; 500×500 px minimum from Jan 31, 2027
`price`	Required; must match the site; excludes tax in US/CA, includes VAT/GST elsewhere
`availability`	`in_stock` · `out_of_stock` · `preorder` · `backorder`; preorders need `availability_date`
`brand`	Required for new products (except movies, books, music); ≤70 characters
`gtin` / `mpn`	GTIN strongly recommended and never guessed (a wrong value means disapproval); MPN only without a GTIN; `identifier_exists=no` only when identifiers truly don't exist
`item_group_id`	Required for variants in BR, FR, DE, JP, UK and US; ≤50 characters

AI-written titles and descriptions go in structured_title / structured_description, not the plain fields.

Attributes Google named for AI Mode

On January 11, 2026 Google announced dozens of new attributes for AI Mode, Gemini and Business Agent. It names six on its help page and suggests adding them through a supplemental data source:

question_and_answer — up to 30 Q&A pairs, 10,000 characters in total.
related_product — up to 30 entries, typed as substitute, accessory and so on.
item_group_title (≤150) and variant_option (up to 30 pairs) — describe the product family and its options.
document_link and popularity_rank.

Two long-standing attributes also carry product facts AI can quote: product_highlight (2–100 items, ≤150 characters each) and product_detail (up to 100 entries, values ≤1,000 characters).

UCP and the Buy button

Universal Commerce Protocol (UCP): an open standard launched January 11, 2026, co-developed with Shopify, Etsy, Wayfair, Target and Walmart. The merchant stays merchant of record.
It powers a Buy button in AI Mode and Gemini through Google Pay, in early access for select merchants via an interest form. The button needs native_commerce(checkout_eligibility) = true.
Google's FAQ says a native integration doesn't change ranking.

Google's pages differ on UCP markets: one lists US, Canada and Australia; the developer guide says US now, with Australia and Canada due early next year.

Content API is gone: use the Merchant API

Google sunset the Content API for Shopping on August 18, 2026. New integrations and fixes should use the Merchant API. Since September 16, 2026, AI performance insights show AI Mode and AI Overviews share of voice for organic traffic in Australia, Canada, India, New Zealand and the US.

Questions

Is a Merchant Center feed the same as a Gemini feed?

Merchant Center is the product data Google's AI experiences use, but an approved product isn't guaranteed to appear in Gemini or AI Mode.

Which new attributes does Google want for AI Mode?

Google names six: question_and_answer, document_link, related_product, item_group_title, variant_option and popularity_rank.

Can AI rewrite my product titles?

Put AI-written versions in structured_title and structured_description; plain titles and descriptions must match your landing page.

Do I need UCP to appear in AI Mode?

No. UCP is for checkout in AI Mode and Gemini (early access). Product data in Merchant Center is what discovery uses.