What Is the Agentic Commerce Protocol (ACP)?

The Agentic Commerce Protocol (ACP) is an open standard, co-developed by OpenAI and Stripe, that defines how an AI agent, a buyer, and a business communicate to complete a purchase without the buyer leaving the agent's chat interface.

Key facts

• Co-developed by OpenAI and Stripe, announced September 29, 2025. Per Stripe's official blog post, the two companies jointly built the specification and tested it with real users to refine trust, standardization, and flexibility requirements.
• First shipped as "Instant Checkout" in ChatGPT. Stripe's newsroom announcement states Instant Checkout let US ChatGPT users buy from Etsy sellers at launch, with over one million Shopify merchants (named examples: Glossier, Vuori, Spanx, SKIMS) planned to follow.
• Core mechanism: a four-party checkout flow. Per Stripe's blog: the buyer selects products and approves checkout through the AI interface; the agent collects payment details and requests checkout from the merchant; the business evaluates and processes the transaction as merchant of record; the payment provider securely tokenizes credentials for programmatic charging.
• Open-source, Apache-2.0 licensed. Confirmed on the official agentic-commerce-protocol GitHub organization, which hosts OpenAPI specs, JSON Schemas, and RFC documents covering agentic checkout, capability negotiation, and payment handlers.
• Governance: OpenAI and Stripe as Founding Maintainers. The GitHub repository states ACP is "jointly governed by OpenAI and Stripe as Founding Maintainers," with a stated path toward broader community governance.
• Salesforce announced support for ACP on the same timeframe, per Salesforce's press release (dated October 14, 2025), indicating third-party adoption beyond the two founding companies.

How it works

1. A buyer expresses a shopping intent to an AI agent (e.g., inside ChatGPT) and browses or is shown matching products.
2. The buyer approves checkout of specific items through the agent's conversational interface — this approval step happens before any charge is made.
3. The agent, acting as the buyer's proxy, sends a structured checkout request to the business (merchant) using ACP's standardized API — this is the capability negotiation step, where agent and merchant confirm what payment methods and options are supported.
4. The business evaluates the order and processes it as the merchant of record, retaining responsibility for the transaction as it would with any other sale.
5. The payment provider (e.g., Stripe) tokenizes the buyer's payment credentials so the agent can request a charge programmatically without ever handling raw card data.
6. The business fulfills the order and confirms back through the same protocol, keeping the entire flow inside the chat interface.

ACP vs. x402 vs. AP2

FAQ

What does ACP stand for? Agentic Commerce Protocol — an open standard for AI agents, buyers, and businesses to complete purchases, co-developed by OpenAI and Stripe and announced September 29, 2025.

Is ACP the same as Instant Checkout? No. Instant Checkout is the first product built on ACP, letting US ChatGPT users buy from merchants like Etsy sellers directly in chat. ACP is the underlying open protocol.

Who is the merchant of record in an ACP transaction? The business selling the product, not OpenAI or Stripe — per Stripe's blog, the business "evaluates and processes the transaction as the merchant of record."

Is ACP open source? Yes, licensed under Apache 2.0, with specs and reference implementations on the official GitHub organization.

Does ACP support stablecoins? Not specified in the primary sources (Stripe's blog, newsroom post, and docs) reviewed for this article — ACP's described mechanism centers on card-rail tokenization via existing payment processors.

Related terms

• Agentic payments
• x402 protocol
• Agent Payments Protocol (AP2)
• AI agent wallet