Merchant Center, UCP and shopping visibility in Gemini

#01Which data feeds AI shopping answers?

Deeper guides: Merchant Center product feeds for AI shopping, How AI Mode shopping picks products and Schema markup for AI search.

#02Which feed attributes matter most for AI answers?

Our view, based on how conversational queries work: AI Mode answers questions like "for flat feet", "under $500" or "quiet for an apartment". The product needs attributes that make those facets matchable.

#03What is UCP and how does checkout work?

From Merchant Center Help:

• UCP is an open standard for agentic commerce. On Google it powers checkout in AI Mode and Gemini on eligible product listings.
• Shoppers see a checkout button, pay with Google Pay using cards saved in Google Wallet, and you stay the seller of record.
• It's compatible with protocols such as A2A, AP2 and MCP.
• It applies to products with eligibility in the United States, Canada and Australia, for select merchants.

Requirements:

UCP checkout vs agentic checkout: UCP checkout happens on Google surfaces. Agentic checkout is when Google's agent completes a purchase on your own website for the shopper. They're different features with different setups.

#04How do you add native_commerce?

native_commerce is a group attribute with the sub-attribute checkout_eligibility (true or false).

TSV supplemental feed:

id	native_commerce(checkout_eligibility)
SKU-1001	true
SKU-1002	true
SKU-2001	false

XML:

<g:native_commerce>
  <g:checkout_eligibility>true</g:checkout_eligibility>
</g:native_commerce>

Steps:

1. Complete the interest form and integration first. The attribute alone doesn't enable checkout.
2. Create a supplemental feed in Merchant Center keyed on id.
3. Add the native_commerce(checkout_eligibility) column.
4. Link it to your primary data source and process it.
5. Confirm on the Data sources tab that the attribute is applied.

#05How should you prioritise?

Our view: UCP is promising but early. The feed is what decides whether you appear at all, and that work pays off in Shopping ads, free listings and AI answers whether or not you join UCP.

#06Worked example: Ledgerline

Ledgerline is a fictional accounts-payable software company. Details are illustrative.

Ledgerline sells software, but its sister brand Ledgerdesk sells office furniture in the US, and reused the same team.

Walkthrough

1. The ecommerce lead ran 20 conversational desk prompts in AI Mode and logged the products shown.
2. She compared the winning products' attributes with Ledgerdesk's feed and found the noise and size facets missing.
3. A supplemental feed added product_detail and product_highlight values, using verified specs only.
4. GTINs and return policies were fixed in Merchant Center.
5. UCP interest was registered, and native_commerce stayed false until the developer completed the checkout-sessions integration and testing.

#07Common mistakes

• Treating UCP as a feed toggle. It needs an integration.
• Overwriting the primary feed instead of using supplemental feeds.
• Facet claims you can't support.
• Missing GTINs and return policies.
• Page price that doesn't match the feed price.

#08Try it yourself

Pick one hero product. Ask AI Mode three conversational questions it should win. For each, list the facet in the question and find the feed attribute that states it. Add any missing facts to a supplemental feed draft. Don't process it until the facts are verified.

#09Quick quiz

1. Who is seller of record in UCP checkout?

Answer: The merchant.

2. Which countries does UCP checkout apply to?

Answer: The US, Canada and Australia, for select merchants.

3. How should you add native_commerce?

Answer: Through a supplemental feed, with checkout_eligibility set to true for eligible products.

#10What should you check before the next lesson?

• Feed diagnostics are clean for top products.
• Conversational facets are covered by attributes.
• You've made a UCP decision and named an owner.

Previous: Content formats that get cited in Gemini and AI Mode. Next: Track Gemini and AI Mode traffic in GA4. Or return to the Gemini for Marketers track. Related: Agentic checkout protocols, How AI agents browse, compare and buy, Perplexity shopping, publishers and ads.

#11Common questions

What is UCP? The Universal Commerce Protocol is an open standard for agentic commerce. On Google it powers a checkout button on eligible product listings in AI Mode and Gemini, with the merchant as seller of record.

Where is UCP checkout available? Google says it applies to products with eligibility in the United States, Canada and Australia, for select participating merchants who complete an interest form and the technical integration.

How do I mark products for UCP checkout? Add the native_commerce group attribute with checkout_eligibility set to true, ideally through a supplemental feed so your primary feed and campaigns are untouched.