The ACP protocol
ACP, the Agentic Commerce Protocol, is an open standard developed by OpenAI and Stripe. Since 29 September 2025 it has powered Instant Checkout in ChatGPT, where people can buy without leaving the chat.
Brand Design Ltd. in Varna has an ACP profile on the same catalogue and order records it uses for every other channel. Below is how the protocol works and what you can check.
What ACP is
ACP is open source under the Apache 2.0 licence. Any business can implement it so that any AI agent can start a checkout, with any compatible payment provider. OpenAI was the first AI platform to use it, and Stripe the first payment provider, with its shared payment token.
The business stays the merchant of record. It decides which products are sold, how they are shown and how orders are fulfilled, and it can accept or decline each agent and each transaction.
How a purchase goes through ACP
The business opens its checkout to agents
The business publishes checkout endpoints for agents, through an ordinary API or through MCP. They work with its existing shop and payment provider.
The agent runs the checkout
The agent creates the checkout for the buyer, updates it and completes it. The business returns the price, the terms and the order.
Payment without exposing the card
The buyer’s payment credential reaches the business as a token through the payment provider, so neither the agent nor the business sees the card data.
ACP at Brand Design Ltd.
Our ACP profile uses the same catalogue and the same order records as our direct API, our UCP checkout and our MCP server. An agent pays with a Stripe shared payment token, and only for an offer that has been accepted with a concrete amount.
What this page does not claim
Supporting ACP does not list a business in ChatGPT. Our profile is open to agents, but selling through Instant Checkout in ChatGPT requires an application and OpenAI’s approval.
Official sources
OpenAI’s announcement, 29 September 2025
Related pages
- UCP, ACP and AP2: the three protocols of agentic commerce
- The UCP protocol
- The AP2 protocol
- Agentic commerce service
- B2A glossary: terms and protocols
- What is agentic commerce? A live test
Frequently asked questions
What is ACP?
ACP, the Agentic Commerce Protocol, is an open standard from OpenAI and Stripe that lets an AI agent complete a purchase with a business on behalf of a buyer.
Who uses ACP?
OpenAI uses it for Instant Checkout in ChatGPT, and Stripe was the first payment provider to support it. Any business or AI platform can implement it.
Does ACP put my products in ChatGPT?
No. Implementing ACP makes your checkout ready for agents. To sell in ChatGPT you also have to apply to OpenAI.
Should a business choose ACP or UCP?
It does not have to choose. ACP is the protocol behind checkout in ChatGPT, and UCP is Google’s standard for the whole purchase. We support both on the same catalogue.