Guides

Agentic commerce explained: ACP, UCP and what AI shopping needs from a store

In short

Agentic commerce, or agentic e-commerce, is shopping an AI assistant does for a person: it finds, compares and checks out through doors a shop publishes. The Universal Commerce Protocol (UCP) and the Agentic Commerce Protocol (ACP) are open standards for that checkout; the shop stays the merchant of record.

Agentic commerce vs e-commerce

In e-commerce a person clicks through a shop's pages. In agentic commerce they ask an assistant, ChatGPT, Gemini, Copilot or another, and the assistant does the clicking, through machine doors: a catalogue it can search, a checkout it can call, and a way to pay without typing a card number. The person still says yes before anything is bought.

What the check counts for a shop, door by door, is in the selling guide; how agents pay, in the payments guide.

The Universal Commerce Protocol (UCP)

UCP is open source, under Apache 2.0. It covers a catalogue, a cart, a checkout, identity linking (OAuth 2.0) and the order, over REST and JSON-RPC, with AP2, A2A and MCP built in. Its site lists co-developers for shopping (Google, Shopify, Etsy, Walmart and Stripe among them), for lodging (Booking.com, Expedia, Marriott and others) and for food (DoorDash, Square, Toast and Uber Eats). The lodging part is a draft, and food is coming. (UCP: the Universal Commerce Protocol)

Google's UCP checkout is a Buy button in AI Mode and the Gemini app, paid with Google Pay, for products eligible in the US, Canada and Australia, and for select merchants for now. The merchant stays the seller of record; joining takes an interest form and a technical implementation. (Google Merchant Center Help: checkout with UCP)

The Agentic Commerce Protocol (ACP)

ACP is an open standard, under Apache 2.0, from Stripe and OpenAI. ChatGPT implemented it, with Stripe's Shared Payment Token for the payment. Businesses stay the merchant of record, and each AI platform runs its own application process. (ACP: the Agentic Commerce Protocol)

In March 2026 OpenAI deprioritised Instant Checkout, its checkout inside ChatGPT, as a stand-alone feature: merchants use their own checkout, and can still offer one through their own app inside ChatGPT. Walmart's app there has its own payments. (TechCrunch, 24 March 2026; MacRumors, 25 March 2026)

ACP, UCP, MCP and AP2: the difference

UCP and ACP describe shopping: a catalogue, a cart, a checkout, an order. MCP, the Model Context Protocol, is a general way for an assistant to call a tool on a server, a checkout among them; UCP can run over it. AP2, the Agent Payments Protocol, is for an agent paying with its person's approval, given as a mandate. A shop may publish more than one: they are doors to the same shop. (UCP: the Universal Commerce Protocol; ACP: the Agentic Commerce Protocol)

Which assistants check out where

What each one does with a shop, as of October 2026:

What a small shop needs

A checkout an assistant can use. Shopify publishes a UCP profile for eligible stores (Shopify and AI assistants). WooCommerce® lists UCP and ACP as coming soon. Elsewhere, ask your platform, or have one built (the selling guide). (WooCommerce®: agentic commerce)

Products, prices and stock an assistant can read: a product feed, or markup on your pages.

A way to ask you, get a quote, change, cancel and return. Shop checkouts rarely cover these. An agent inbox is one way: Surfing Dog Inbox (ours, open source) takes questions, quotes and orders at your own address and sends buyers to your shop's checkout (what it connects to).

WooCommerce and its associated designs are trademarks of Automattic Inc.

Check your website

Paste your website. We read it the way a customer's assistant would, and show what it can do there, what's missing, and where to start.

Or open the free AI agent readiness checker. If your site was read recently, you'll see that read, and when you can ask for a fresh one.

Questions

What is the difference between ACP and UCP?

Both are open standards for an assistant's checkout, and in both the shop stays the merchant of record. ACP, the Agentic Commerce Protocol, comes from Stripe and OpenAI. UCP, the Universal Commerce Protocol, was co-developed by Google, Shopify and others, and covers the catalogue, cart, identity linking and order too.

What is the difference between ACP and MCP?

ACP describes a checkout. MCP, the Model Context Protocol, is a general way for an assistant to call tools on a server, whatever they do: search a catalogue, book a time, ask a question. A shop can offer both.

How do AI agents pay?

With a credential made for agents, such as a token or a mandate the person approved, through the shop's checkout or payment provider; or a person pays on a payment link the agent hands them. An agent should never type a card number.

Can ChatGPT buy things for you?

ChatGPT finds and compares products. Since March 2026 OpenAI lets merchants use their own checkout, opened from ChatGPT, and a shop's own app inside ChatGPT can take payment, as Walmart's and Square's do. Gemini and Copilot check out inside the chat in some countries, with merchants they admit.

How do I sell to AI agents?

Publish a checkout an assistant can use, through your shop platform or UCP or ACP; keep your products, prices and stock readable; and give assistants a way to ask, get a quote, change, cancel and return. Our free check shows what your site offers today.

Sources, as of October 2026