What is agentic commerce?
Agentic commerce is shopping where an AI agent does the work for a person: it finds products, compares them, builds a cart and gets to checkout, with the person approving the payment. As of late 2026 it runs on a few open protocols, led by the Universal Commerce Protocol (UCP) that Google and Shopify co-developed, alongside OpenAI and Stripe's Agentic Commerce Protocol (ACP) and Google's AP2 for payment authorization.
The protocols
UCP (Universal Commerce Protocol)
Announced by Google and Shopify in January 2026. A store publishes a profile at /.well-known/ucp that lists its services and capabilities (catalog, cart, checkout, orders, identity linking) and the endpoints agents call, including an MCP endpoint. Live profiles we checked on 3 Nov 2026 reported version 2026-08-25.
ACP (Agentic Commerce Protocol)
Open-sourced by OpenAI and Stripe in September 2025 to power Instant Checkout in ChatGPT. It defines how an agent creates and completes a checkout with a merchant, with Stripe handling payment tokens.
AP2 (Agent Payments Protocol)
Google's protocol for proving a person authorized a purchase, using signed mandates for the intent, the cart and the payment. UCP builds on it for payments.
What happened to Instant Checkout in ChatGPT
OpenAI scaled back Instant Checkout in early March 2026, as Forrester reported on 7 Mar 2026. Checkout moved to merchants' own apps inside ChatGPT or back to merchants' websites. Products are still discoverable in ChatGPT; Shopify says its merchants' products show up there by default, and shoppers finish the purchase in an in-app browser on the store's own checkout.
How to get a store ready
Whichever protocol wins your channel, agents need the same basics: a catalog they can read and a checkout they can reach.
Product and Offer data on product pages
Add Product JSON-LD with an Offer (price, priceCurrency, availability) to every product page.
Prices are plain text
Render prices in the HTML, not with a script after load, so agents can quote them.
Cart and checkout open to agents
Don't put a bot challenge in front of /cart or /checkout for AI user-agents. Challenge suspicious payments instead.
Guest checkout
Let people (and their agents) check out without creating an account, and say so on the page.
A machine-readable catalog
Expose your catalog to agents: a product feed, an agentic commerce manifest (UCP or ACP) or a commerce MCP server.
Shipping and returns pages
Link shipping and returns policies from the homepage and product pages, in plain text.
Check it yourself
The first command shows your UCP profile if you have one. The second fetches your cart as an AI agent: anything other than 200 means agents can't get to checkout. Run the free check with the Buy job for the rest.
curl -s https://example.com/.well-known/ucp | head -c 400
curl -s -o /dev/null -w "%{http_code}\n" -A "Mozilla/5.0 (compatible; Claude-User/1.0)" https://example.com/cartQuestions
Is UCP or ACP better?
They aren't exclusive. UCP powers Shopify's Agentic Storefronts on Google's surfaces and lists Google, Shopify and Stripe among its co-developers; ACP came from OpenAI and Stripe. Most merchants get whichever their platform supports rather than implementing either by hand.
Can I still sell inside ChatGPT?
Products can still be found in ChatGPT. Since March 2026 the purchase happens on the merchant's own checkout (in an in-app browser on mobile) rather than natively in ChatGPT.
Should I block bots from my checkout to stop fraud?
Don't block AI user-agents outright; that also blocks real customers' agents. Challenge suspicious payments instead, and let agents reach the cart and checkout pages.