A broader commerce specification
The repository snapshot expands carts, feeds, orders, authentication and MCP support.
Protocol
Version date; first public release time not established.
The agentic web · A living reference
ACPAgentic Commerce Protocol
Track the Agentic Commerce Protocol from its September 2025 launch: who is behind it, how it works, specification changes and evidence of adoption.
- First announced
- 29 Sept 2025
- Developed by
- OpenAI and Stripe
- Research checked
- In this reference
- 11 milestones · 2025 / 2026
Where it stands
The specification continues to evolve. OpenAI shifted its shopping emphasis towards discovery and merchant checkout in March 2026; ACP’s repository records a further specification snapshot dated 17 April.
A simple guide to ACP
What is ACP?
ACP stands for Agentic Commerce Protocol. It gives AI agents and businesses a common way to exchange the information needed for commerce. OpenAI and Stripe introduced it on 29 September 2025 alongside Instant Checkout in ChatGPT. OpenAI’s launch announcement.
The acronym needs care: other agent projects also use “ACP”. This reference is about the commerce protocol developed by OpenAI and Stripe.
Who is behind it?
OpenAI and Stripe developed the protocol together. Stripe describes the specification as open source under Apache 2.0, with support for compatible payment providers. That describes the protocol’s design and licensing; a particular shopping service can still have its own onboarding and availability limits. Stripe’s protocol announcement.
How does a purchase work?
In the original checkout model, the agent mediates a transaction between the customer and the merchant:
- The customer selects a product and reviews a checkout.
- The agent exchanges checkout information with the merchant.
- An approved payment is represented using a delegated credential.
- The merchant processes the purchase and remains responsible for the order.
OpenAI’s documentation separates product feeds, checkout and delegated payment. The merchant remains the merchant of record. These responsibilities matter when assessing who handles fulfilment, support and returns. OpenAI’s key concepts.
This is a description of the model, not a purchase test. An implementation walkthrough needs a named specification version, a test merchant and recorded results.
What has changed?
On 24 March 2026, OpenAI described a stronger focus on product discovery and more flexibility for merchants to use their own checkout. That is a change to the shopping experience, rather than sufficient evidence that ACP itself ended. OpenAI’s March update.
The repository also records a later specification snapshot, dated 17 April 2026. Its scope includes carts, feeds, orders, authentication and MCP support. Keep the protocol’s development history separate from the availability of any one ChatGPT feature. ACP’s April changelog.
How should adoption be read?
There are several different questions: has a company endorsed the protocol, implemented it, enabled a customer journey, or reported completed purchases? Those are different milestones. Evidence of repeat use, conversion, intervention rates and merchant economics would make a stronger assessment possible.
The timeline below records the evidence and its scope. Australian availability is called out separately so a US rollout does not become an implied local launch.
Latest developments
The ACP timeline.
Newest first. Work backwards through the developments and their original dates.
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Country tags identify the markets named in the evidence. Global updates have no country-specific scope.
11 milestones · newest to oldest
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ChatGPT puts more weight on discovery
OpenAI says its initial Instant Checkout lacked the flexibility it wanted. Merchants can use their own checkout experiences.
OpenAI · ChatGPT shopping
Read the Signal -
Shopify connects discovery to merchant checkout
Shopify describes Agentic Storefronts connecting ChatGPT product discovery with checkout on the merchant’s own store.
Shopify · ChatGPT
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Production lessons from Stripe
Stripe reports implementation lessons from work with Etsy and URBN. This is a vendor account, not an independent performance study.
Stripe · merchant implementations
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Stripe expands payment options
Stripe announces Shared Payment Token support for further network payment and buy-now-pay-later integrations.
Stripe · payment infrastructure
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Extensions, discounts and payment handlers
The next dated snapshot expands the specification’s extension and payment model.
Protocol
Version date; first public release time not established.
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Capability negotiation develops
The specification snapshot adds a way to describe and negotiate supported capabilities.
Protocol
Version date; first public release time not established.
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Fulfilment enters the version history
The dated specification snapshot records fulfilment enhancements.
Protocol
Version date; first public release time not established.
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Stripe packages the integration work
Agentic Commerce Suite brings catalog, checkout and payment integration together. This is a product announcement around the protocol.
Stripe · merchant infrastructure
Read the Signal -
Shopify Instant Checkout begins its US rollout
OpenAI reports Instant Checkout rolling out to Shopify merchants, starting with Spanx, Skims and Glossier, for logged-in Plus, Pro and Free users in the US.
US shoppers · selected Shopify merchants
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ACP launches alongside Instant Checkout
OpenAI and Stripe introduce ACP. US ChatGPT users can buy from US Etsy sellers; Shopify participation is described as forthcoming.
US · limited merchants
Read the Signal
No matching milestones are recorded here. An empty result is an evidence gap. Try another selection or reset the filters.
Dates, sources and evidence
Evidence checked through 7 Oct 2026.
Dates follow the source’s calendar date. Version dates identify specification snapshots; they do not prove the exact day a release first became public.
“Reported rollout” means a platform or retailer reports availability in the stated scope. These entries are source research, not purchase tests conducted by Paul. Announcements, specifications and council membership are recorded separately from adoption.
Country tags follow explicit market statements in the cited sources, including announced plans. They do not follow a company’s headquarters, a translated website or the general availability of ChatGPT, Gemini or AI Mode. Eligibility documentation is recorded in Country watch using the research check date when an original rollout date is unknown.
New findings keep their historical dates and appear newest first. Corrections and substantive reviews update the research date above.