Answers

Top questions

1. Can AI agents buy from my store?

   Sometimes. It depends on whether an agent can reach your site, read your products and get to checkout. ARC checks this for free: paste your store's address at arcreport.ai/agent-checkout to see if agents get a checkout link, whether a browser agent can add to cart, and whether bots are blocked.

2. What is UCP (Universal Commerce Protocol)?

   UCP (Universal Commerce Protocol) is an open standard launched by Google with partners including Shopify. A store publishes a profile at /.well-known/ucp that tells AI agents what it supports, like catalog search, cart and checkout. ARC tracks how many stores declare UCP, how many profiles are valid, and how many actually return a checkout.

3. Which online stores block AI agents?

   Some stores turn AI agents away with bot challenges or blocks, often by accident through their security settings. ARC records when a store returns a bot challenge and shows the HTTP evidence on that store's page. Its tracker shows how many checked stores blocked ARC's latest attempt, and its blocked-agent rates by platform.

4. How do AI shopping agents check out?

   An AI agent checks out in one of two ways. It either talks to the store through a machine-readable protocol like UCP or ACP and gets a checkout link or session, or it drives a web browser like a person, adding to cart and filling forms. Payment usually still needs the buyer's approval. ARC measures both routes.

5. How do I let AI agents buy from my store?

   Turn on agent selling in your commerce platform's settings, make sure your products are in the catalog or feed that AI channels read, and keep a checkout that agents can reach. On Shopify, agentic storefronts are on by default for eligible stores. Then check on ARC that agents actually get a checkout link.

All answers

1. What is agent buyability?

   The canonical definition lives on the existing post. This section does not keep a second copy.

2. Does Shopify support AI agent checkout?

   Yes, broadly. In ARC's checks, most Shopify stores publish a UCP profile and Storefront MCP, and many return an agent checkout link. Support isn't automatic everywhere, though, so check your own store. ARC's adoption tracker shows live Shopify rates next to other platforms.

3. What is ACP (Agentic Commerce Protocol)?

   ACP (Agentic Commerce Protocol) is an open-source standard (Apache 2.0) maintained by OpenAI and Stripe. It defines how an AI agent and a merchant create and complete a checkout. ARC lists ACP on its Protocol Matrix but does not yet measure ACP adoption, so any count you see elsewhere isn't from ARC.

4. UCP vs ACP: what's the difference?

   UCP and ACP are both open standards for letting AI agents buy from stores. UCP, from Google and partners, covers the wider shopping journey through a profile at /.well-known/ucp. ACP, from OpenAI and Stripe, focuses on the checkout handshake. ARC measures UCP adoption across thousands of stores; ACP is not yet measured.

5. What is WebMCP and do stores use it?

   WebMCP lets a web page expose tools that an AI agent in the browser can call, like reading a cart or completing checkout, instead of clicking around the page. ARC detects WebMCP on store pages. Its Protocol Matrix shows how many checked stores declare it, mainly through Shopify's storefront adapter.

6. Can ChatGPT buy from a store?

   ARC doesn't test ChatGPT itself. It checks whether any AI agent can reach a store, read its products and get to checkout, and publishes the result per store. Look up a store on ARC to see if agents get a checkout link and whether the store blocks automated agents. Whether ChatGPT lists it depends on OpenAI's own rules.

7. Can Gemini, Meta's Muse or other AI assistants buy from a store?

   ARC's data is the same starting point for every assistant, whether Gemini, Meta's Muse or another. It measures whether a store lets agents reach it, read products and get to checkout. It doesn't test any assistant's app. Check the store on ARC, then read that assistant's own merchant rules.

8. How do I make my store ready for AI shopping agents?

   Start by checking your store for free on ARC. Then fix what agents trip on most: add-to-cart buttons and size or colour pickers that agents can't use, bot blocks that turn agents away, and missing or invalid UCP profiles. Retest after each change and track your store page over time.

9. How do Visa and Mastercard agent payments work?

   Visa's Trusted Agent Protocol and Mastercard Agent Pay let a registered AI agent prove who it is by signing its requests, then pay with a card token issued for that agent. They sit underneath checkout protocols like UCP and ACP. ARC can't see adoption from outside, so it labels them not measured.

10. What is Shopify Storefront MCP?

    Storefront MCP is an endpoint on Shopify stores that lets AI agents search the catalog and work with carts using the Model Context Protocol (MCP). ARC checks whether a store's MCP server answers. ARC counts cart results under UCP. That split is on the methodology page.

11. Which e-commerce platforms support AI agents?

    In ARC's checks, support for AI agents varies sharply by platform. ARC's adoption tracker shows, for each platform, how many checked stores publish UCP, MCP or WebMCP and return a checkout link, with sample sizes. Platform is detected from public signals, so some stores show as not detected.

12. Which stores can AI agents actually buy from?

    ARC publishes a public index of stores where its browser cart shoppers added a product to the cart. In the 2026-10-12 open dataset, all five shoppers succeeded at 32 of 77 scored stores with Measured evidence, including Allbirds, Glossier, Everlane. The full list is on the ARC Index and in the open dataset.

13. Why do AI shopping agents fail at checkout?

    In the Measured Index, stops follow the dataset order. The Measured stops, most common first, are Couldn't add it to the cart (32), then Blocked at the size picker (8), then Stopped by a human-check (3), then Store blocks automated agents at the door (2). Stores where 0 of 5 shoppers added to cart can still have returned a checkout link. That figure covers Measured scores only, snapshot 2026-10-12.

14. What is PAP (Personal Agent Protocol)?

    The Personal Agent Protocol (PAP) is an open standard announced in October 2026 by Meta and Sierra, with partners, for how personal AI agents interact with businesses. Its v0.1 specification is not published yet. ARC's Protocol Matrix labels PAP adoption Not measured. A missing marker is not a zero, and it is not a mark against a store.

15. How do I check if my UCP profile is valid?

    Paste your store's address into ARC's free UCP validator. It fetches /.well-known/ucp and checks it against the published UCP schema and spec rules, then tells you what's wrong. Developers can call the same check by API or MCP, or add ARC's arc-check step to CI so a broken profile fails the build.

16. How many online stores support agentic commerce?

    In ARC's sample of 4,318 completed store checks, 1,896 of 4,318 (43.9%) declare UCP, and 1,522 of 4,318 (35.2%) return an agent checkout link. These figures are ARC saved checks, accessed 2026-10-13. The weekly snapshot can differ. Live counts are on /protocols. These are dated counts under CC-BY-4.0. The sample is ARC's directory, not the whole web.

17. Should I block AI agents on my store?

    Blocking every AI agent also blocks shoppers who send one to buy for them. Many stores block agents by accident through bot protection. A middle path is to allow agents that identify themselves and to send them to official checkout routes, while still limiting scrapers. ARC shows whether your store currently blocks automated agents.

18. How should I set robots.txt for AI shopping agents?

    robots.txt is advisory. It asks crawlers what to fetch but doesn't stop agents that ignore it. Naming a bot in its own group can switch off your default rules for that bot, so edit with care. Shopify's default doesn't block AI crawlers and adds a note pointing agents to official checkout routes.

19. How do I add UCP to a WooCommerce, BigCommerce or custom store?

    Publish a UCP profile at /.well-known/ucp that lists what your store supports and where its checkout and catalog endpoints are, then build or install those endpoints. Some platforms offer plugins; others need custom work or a catalog-sync service. Validate the profile on ARC's free validator before telling anyone it's live.

20. Who is liable when an AI agent buys from my store?

    In most cases today, the store stays the merchant of record. The UCP and ACP documentation both say so, and a disputed agent purchase is usually handled like any online card payment. Agent payment programmes from card networks may shift some fraud liability. ARC doesn't measure disputes, so check your payment provider's terms.

21. How do I see orders and traffic from AI agents?

    Look in three places: order attribution in your commerce platform (Shopify, for example, labels orders from AI channels), referral sources in your analytics, and server or CDN logs for agent user agents and signed requests. Purchases made inside an AI channel may never visit your site, so platform reports matter most. ARC doesn't see your traffic.

22. What product data do AI shopping agents need?

    Agents need clear, consistent product data: exact title, price, currency, stock, variants such as size and colour, images, shipping and return terms, and identifiers like GTINs. It should match on your page, your feed and your structured data. ARC scores product data quality per store and shows where an AI read-back disagrees with the page.

23. What do AI agents get wrong about my products, and how do I fix it?

    Agents most often get prices, stock, variants and policies wrong when a store's pages, feeds and structured data disagree or can't be read. ARC compares one AI model's read-back with your actual store pages and flags mismatches on your free store page. Fix the source data first, then retest.

24. How do I compare my store's agent readiness with competitors?

    Look up each store on ARC. Every store has a free page with the same checks, and ARC's Index lists stores by category, such as apparel, beauty and electronics. Compare like with like: the same date, the same check type and the sample size. Add missing competitors through the free submit form.

25. How do I make sure my store stays agent-ready after changes?

    Theme updates, apps and bot settings can quietly break agent access. Recheck your store after every change: ARC's free store page keeps a simple history. Developers can add ARC's arc-check step to their build so it fails when the UCP profile or WebMCP breaks. Claim your store card to keep a contact on file.