UCP Checker & Validator /.well-known/ucp

Stripe and Agentic Commerce: What Merchants Need to Know

Stripe's own standard for agentic commerce is not UCP, it is ACP, the Agentic Commerce Protocol, co-developed with OpenAI and Meta. Here is what ACP actually does, what integrating it takes, and how it relates to UCP if that is what you are actually trying to check for.

Read this first

If you came here specifically looking to add UCP support and use Stripe for payments, know that Stripe's protocol and UCP are two separate, independently governed standards. Stripe does not implement UCP directly. This guide covers what Stripe actually offers, ACP, and where it stands relative to UCP so you can decide which one, or both, is relevant to you.

What ACP actually is

The Agentic Commerce Protocol is an open standard, created by Stripe, OpenAI, and Meta, that defines how AI agents interact with businesses to complete purchases on a buyer's behalf. It launched September 29, 2025, alongside Instant Checkout in ChatGPT, and is released under the Apache 2.0 license, meaning any business or AI platform can implement the specification without licensing it from Stripe.

Per Stripe's own documentation, ACP defines four composable building blocks:

  • Agentic checkout, creating, updating, and completing checkout sessions
  • Cart and feed, browsing product catalogs and managing carts before checkout
  • Delegate payment, securely passing payment tokens between buyer, agent, and business
  • Delegate authentication, OAuth 2.0-based authorization for agents acting on a buyer's behalf

How it actually works

In ChatGPT's Instant Checkout, a buyer asks for product recommendations, then is shown a Stripe-powered checkout inline in the chat. When they pay, Stripe issues a Shared Payment Token (SPT), scoped to a specific merchant and cart total, so ChatGPT can initiate the payment without ever seeing the buyer's actual card details. ChatGPT passes that token to the merchant through an API, and the merchant remains the merchant of record, able to accept or decline the order, calculate tax, and manage fulfillment and returns themselves.

At launch, this supported single-item purchases from US Etsy sellers, with Shopify merchants (Stripe named Glossier, Vuori, Spanx, and SKIMS as early examples) added afterward. Salesforce announced its own ACP support in October 2025.

What integrating it actually takes

This depends heavily on where you are starting from.

Already processing payments with Stripe

Minimal lift

Per Stripe's own blog: "you will be able to enable agentic payments in your existing integration by updating as little as one line of code." This covers accepting Shared Payment Tokens through Stripe's existing PaymentIntents API.

Using a different payment processor

Still possible

Stripe's documentation states you can still use Stripe specifically for the agentic payment layer, while continuing to process your regular payments through your existing provider.

Worth knowing before you start

Stripe itself has been candid that accepting a payment token is the easy part. Becoming genuinely discoverable and transactable across multiple AI agents, each with its own catalog format and API requirements, is a heavier lift, one Stripe's own blog described as potentially taking "up to six months for every new AI agent you support" if built from scratch. That is the specific gap Stripe's separate Agentic Commerce Suite product, launched in December 2025, is meant to close: a hosted ACP endpoint, product catalog syndication to agents, and a more unified setup, rather than building and maintaining that integration layer yourself.

ACP vs UCP

Both are real, open standards for the same underlying problem, letting AI agents transact with merchants, but they come from different groups and are not interchangeable.

ACPUCP
AnnouncedSeptember 29, 2025January 11, 2026
Led byStripe, OpenAI, and MetaGoogle, with Shopify, Etsy, Wayfair, Target, and Walmart
Primary surfaceChatGPT (Instant Checkout), and adopters like SalesforceGoogle AI Mode and other UCP-compatible agents
Core mechanismShared Payment Tokens via Stripe's PaymentIntents APIA JSON manifest published at /.well-known/ucp

A merchant is not limited to one. Since both are open, Apache-style standards, a business can implement ACP, UCP, or both, depending on which AI agents its customers actually use. For a deeper look at UCP specifically, see our Universal Commerce Protocol guide.

Checking for UCP specifically?

If your actual goal is UCP compliance rather than ACP, check whether a manifest is present and correctly structured.

Frequently asked questions