How AI agents actually buy things

Agentic commerce is the idea that someone tells an assistant what they want and the assistant handles the rest — finding it, comparing it, buying it. The pitch is everywhere. The implementation is narrower than the pitch, changed direction in March, and still matters for your shop. Here is what actually exists, stripped of the roadmap talk.

The three protocols

MCP is included because it is routinely listed alongside the other two, but it is a different kind of thing: a way for a model to reach live data and tools, which commerce can be built on rather than a commerce standard itself.

The part that quietly reversed

ACP launched in September 2025 letting a purchase complete inside ChatGPT — the assistant took the payment, the customer never left the conversation. That was the genuinely new thing, and in March 2026 OpenAI deprecated Instant Checkout. What the model does now is discovery, then a redirect to the merchant’s own checkout.

So the state of the art, after eighteen months and three protocols, is a very well-informed referral. That is worth saying plainly, because it changes what you should prepare for: not a payment integration, but being findable and legible to something reading on a shopper’s behalf.

The number that is not reversing

Adobe measured a 4,700% year-over-year increase in generative-AI referred traffic to US retail sites between July 2024 and July 2025. From a tiny base, and US-only — but the direction is not ambiguous, and the visitors arriving this way have already had the comparison done for them.

That is the practical shift. A shopper who arrives from an assistant has been pre-briefed on price, specification and alternatives, and lands closer to a decision than one who arrived from a search result. It changes which page they land on and what that page has to do.

What actually makes a shop legible to an agent

None of it is exotic, and all of it is the same work that helps human shoppers and search engines. Complete, accurate structured data on every product — price, availability, currency, shipping and returns — is the single highest-value item, because it is the difference between a model quoting you correctly and quoting you approximately.

After that: stable product URLs, machine-readable stock status, and shipping and return terms stated as facts rather than buried in a PDF. If your prices or stock levels are only rendered by JavaScript after a click, assume they do not exist. Our API integrations work covers the plumbing where a catalogue has to stay in sync.

What not to do yet

Do not buy an agentic-commerce integration on the strength of the marketing. The protocols are competing, one has already retreated from its headline feature, and picking a winner in 2026 means committing engineering to a standard that may not be the one that survives.

The hedge is to do the legible-catalogue work, which pays off regardless of which protocol wins — it is the same investment that improves your search listings and your own on-site search. Then revisit in six months, when the field has thinned.

Where the money still leaks

It is worth keeping this in proportion. A shop losing seven in ten carts at checkout does not have an AI-agent problem, it has a checkout problem, and the second one is both larger and entirely fixable today — we went through the causes here.

Agentic traffic is a channel to prepare for, not a reason to reprioritise. Get the catalogue clean and the checkout working, and you will be in the best position for whichever protocol turns out to matter. If you are still choosing a platform, headless commerce covers how much of this is architecture rather than integration.

Sources

Checked September 2026. This area moves quickly — the protocol details in particular are worth re-checking before acting on them.

• Opascope — AI shopping assistant guide 2026: agentic commerce protocols ↗

  The UCP / ACP / MCP breakdown in the table, the September 2025 ACP launch, and the March 2026 deprecation of Instant Checkout in favour of discovery plus redirect.

• Fin AI — What is agentic commerce? The 2026 guide ↗

  Definition of the model and the state of merchant adoption, including ACP processing live transactions for Etsy and expanding past a million merchants.

• Digital Applied — Agentic commerce readiness: a 2026 checklist for stores ↗

  Source of the Adobe Analytics figure — a 4,700% year-over-year rise in generative-AI traffic to US retail sites, July 2024 to July 2025 — and of the catalogue-readiness items.