Agentic commerce explained: how AI agents shop and pay (ACP, AP2)
Agentic commerce is online shopping in which an AI agent searches, compares and pays on a person's behalf, within limits that person has set. It needs new plumbing, because card networks, checkout pages and fraud systems all assume a human clicks "buy." As of October 2026, several competing protocols and network programmes are trying to supply that plumbing, and none has become the single standard.
What agentic commerce means
In ordinary e-commerce, a person browses, picks a product and enters payment details. In agentic commerce, the person states a goal ("a pair of white running shoes under $100") and software does the legwork: finding options, filling the cart and, if allowed, completing the payment.
Three questions keep coming up, and Google framed them clearly when it announced its protocol: authorization (did the user really permit this purchase), authenticity (does the request reflect what the user wanted) and accountability (who is responsible if something goes wrong). Every system below is an answer to some mix of these.
The main protocols and programmes
Agentic Commerce Protocol (OpenAI and Stripe)
Stripe announced the Agentic Commerce Protocol (ACP) on September 29, 2025, co-developed with OpenAI. It is open source under the Apache 2.0 licence. The project site describes it as a standard for commerce flows between buyers, AI agents and businesses, with the business remaining the merchant of record.
The first product built on it was Instant Checkout in ChatGPT. At launch, US ChatGPT users could buy from US Etsy sellers inside the chat, and Stripe said over a million Shopify merchants were "coming soon." Per Stripe, the agent relays payment credentials to the merchant's payment provider through a secure token whose use is programmatically controlled, permissioned and logged, so the agent does not hold raw card details.
For merchants, OpenAI's commerce documentation says integration starts with a structured product feed and an implementation of its Agentic Checkout Spec. That page does not state fees, and Stripe's announcement does not either. Check current terms with OpenAI and your payment provider before assuming a cost.
Agent Payments Protocol, AP2 (Google)
Google introduced AP2 on September 16, 2025, built with more than 60 organisations including Adyen, American Express, Coinbase, Etsy, Mastercard, PayPal and Worldpay. It is open (the repository is Apache-2.0), payment-agnostic, and designed to work as an extension of Google's Agent2Agent and Anthropic's Model Context Protocol. It covers cards, stablecoins, real-time bank transfers and crypto.
Its distinctive idea is the mandate, a cryptographically signed record of what the user authorised:
- Intent Mandate: the user's instruction, which for delegated tasks can include price limits and timing.
- Cart Mandate: the exact items and price the user approved, so the final purchase can be checked against it.
Chained together, these give an audit trail from request to payment, which is the basis for settling disputes.
Visa Intelligent Commerce
Announced on April 30, 2025, this is Visa's programme for opening its network to AI agent developers. It centres on tokenised "AI-ready" credentials that show a consumer's chosen agent is authorised, spending limits set by the consumer, and transaction signals Visa can use for controls and disputes. Visa named Anthropic, IBM, Microsoft, Mistral AI, OpenAI, Perplexity, Samsung and Stripe among its partners.
Mastercard Agent Pay
Mastercard announced Agent Pay on April 29, 2025. It uses "Agentic Tokens" built on Mastercard's existing tokenisation, requires agents to be registered and verified before transacting, and lets consumers set purchase limits. Microsoft, IBM, Braintree and Checkout.com were named as early partners.
Personal Agent Protocol (Meta, Walmart, Stripe, Sierra)
The newest entrant. On October 6, 2026, SiliconANGLE reported that Meta, Walmart, Stripe and Sierra Technologies are backing a Personal Agent Protocol, introduced by Sierra co-founder Bret Taylor. It aims to help businesses recognise purchases made by authorised agents and see what those agents do on their sites and APIs; Taylor called it open for anyone to implement. As of October 2026 Taylor, who chairs OpenAI Group PBC, is reported to expect OpenAI to back it later.
How the layers fit together
These are not all rivals. A rough split helps:
- Checkout protocols (ACP, and the Personal Agent Protocol as proposed) define how an agent talks to a merchant.
- Authorisation protocols (AP2) define how a user's permission is recorded and proven.
- Network programmes (Visa, Mastercard) define how card credentials are tokenised and controlled for agents.
A single purchase could in principle touch all three layers. In practice, interoperability between them is still being worked out, and merchants may end up supporting more than one.
Where agents and retailers collide
Protocols only help when the store agrees to take part. In the SiliconANGLE report on the Personal Agent Protocol, Amazon is described as having barred Meta's Muse shopping agent from its platform because the agent did not identify itself, which raised questions about how it would handle account data and credentials. The episode shows the core tension: retailers want to know who, or what, is shopping on their site.
What it means for merchants
The business questions are practical:
- Opt-in: under ACP, merchants implement a checkout spec and share a product feed. They stay merchant of record and can decline orders.
- Liability: this is the least settled part. AP2's mandates and the network programmes' dispute signals are attempts to assign responsibility, but no universal rule exists as of October 2026. We follow how companies are handling this in our AI business coverage.
- Fees: the primary sources reviewed here do not publish fee schedules. Treat any figure in secondary coverage as unverified until the platform confirms it.
For startups building in this area, the funding activity is visible in our funding section, and product news lands under launches. Payments events are another place the topic surfaces; see our guide to Money20/20 USA 2026.
Frequently asked questions
What is agentic commerce in simple terms?
It is shopping where an AI agent does the searching, comparing and sometimes the paying for you. You set the goal and the limits, and the agent acts within them.
What is the Agentic Commerce Protocol?
ACP is an open-source standard from Stripe and OpenAI, announced on September 29, 2025, that lets AI agents start checkout with a business. The business stays the merchant of record. ChatGPT's Instant Checkout was the first product built on it.
What is Google's Agent Payments Protocol (AP2)?
AP2 is an open protocol Google announced on September 16, 2025. It uses signed "mandates" to prove what a user authorised, so merchants and payment firms can verify an agent's purchase and assign responsibility if something fails.
Is ChatGPT Instant Checkout available to every merchant?
At its September 2025 launch it was limited to US users and US Etsy sellers, with Shopify merchants listed as coming soon. The feature's scope may have changed since, so merchants should check OpenAI's current commerce documentation for eligibility and terms, since they can change.
Who is liable if an AI agent buys the wrong thing?
There is no single rule as of October 2026. Protocols such as AP2 record what the user approved to help settle disputes, and card networks apply their own dispute processes, but the outcome depends on the payment method and the contracts involved.