What is the Agentic Commerce Protocol (ACP)?
Last verified 2026-09-01The Agentic Commerce Protocol (ACP) is an open standard, co-developed by OpenAI and Stripe and announced on 29 September 2025, that connects AI agents, buyers and businesses. It powered Instant Checkout in ChatGPT from launch, starting with US Etsy sellers. On 24 March 2026 OpenAI announced a focus on product discovery and merchant checkout, extending ACP: merchants push feeds and promotions into ChatGPT over the protocol and keep checkout on the merchant side or inside a ChatGPT app. ACP is licensed under Apache 2.0 and maintained on GitHub by OpenAI and Stripe (currently beta). The historical Instant Checkout materials describe Stripe Shared Payment Tokens, but they do not establish a current native ChatGPT checkout integration.
Key facts
| Author / steward | OpenAI and Stripe |
|---|---|
| Announced | 2025-09-29 |
| License | Apache 2.0 |
| Governance | Founding maintainers OpenAI and Stripe, with a stated path toward broader community governance |
| Scope | Open standard connecting buyers, their AI agents and merchants; it powered Instant Checkout in ChatGPT from September 2025, and since March 2026 it carries product discovery, merchant feeds and promotions into ChatGPT while merchants run their own checkout |
| Transport | HTTP (OpenAPI/JSON Schema); MCP support added in the 2026-04-17 spec |
| Payment | Delegated Payments Spec; Stripe Shared Payment Token (SPT) for agent-initiated payments without exposing credentials |
| Maturity | beta |
What makes it distinctive
- Co-developed by Stripe and OpenAI, announced 29 September 2025
- Open source under Apache 2.0, spec maintained on GitHub by OpenAI and Stripe
- Powered Instant Checkout in ChatGPT from September 2025 (Etsy first, then Shopify merchants)
- On 24 March 2026 OpenAI extended ACP to product discovery and let merchants keep their own checkout, saying the initial Instant Checkout did not offer the flexibility it wanted
- Target, Sephora, Nordstrom, Lowe's, Best Buy, The Home Depot and Wayfair integrated ACP for discovery
- Merchant stays merchant of record; works with existing payment processors
- One-line enablement for existing Stripe merchants via Shared Payment Token
How ACP works
ACP defines an interaction model between the buyer, the buyer’s AI agent and the business. Its specification includes checkout-session and delegated-payment semantics alongside catalogue and feed capabilities. The historical ChatGPT reference implementation sent an order from the agent to the merchant’s backend; the merchant accepted or declined it, charged the payment method, calculated tax and handled fulfillment and returns. Since 24 March 2026, OpenAI documents ACP in ChatGPT for product discovery: merchants share feeds and promotions, while checkout happens on the merchant side or inside a ChatGPT app. Stripe’s Shared Payment Token is part of the historical checkout material and must not be read as a current ChatGPT checkout guarantee.
Specification, versions and governance
The specification lives on GitHub under agentic-commerce-protocol (Apache 2.0) and uses date-based versioning. Five versions have shipped: 2025-09-29 (initial release), 2025-12-12 (fulfillment enhancements), 2026-01-16 (capability negotiation), 2026-01-30 (extensions, discounts, payment handlers) and 2026-04-17 (cart, feed, orders, authentication and MCP support). Each version ships OpenAPI YAML, JSON Schemas and examples. RFCs cover agentic checkout, capability negotiation, payment handlers, seller-backed payment handlers, extensions and a discount extension. Governance is consensus-based between the founding maintainers OpenAI and Stripe, contributions require a CLA, and the project states a path toward neutral foundation stewardship as the ecosystem matures.
How ACP fits the stack
ACP is the commerce specification attached to the ChatGPT surface. In the current ChatGPT rollout it is the product-discovery path, not the former native checkout flow. It does not replace the context layer (MCP): since the 2026-04-17 version, ACP can run over MCP as a transport. It overlaps with UCP in its commerce capabilities, while UCP documents agentic checkout on Google AI Mode and Gemini. AP2 addresses payment authorization across networks rather than a single commerce surface (ACP vs AP2), and Visa’s TAP is positioned by Visa as complementary to ACP for agent verification.
Limitations and open questions
ACP is in beta, and its clearest limitation is documented by its own author. Instant Checkout launched on 29 September 2025 for US ChatGPT users with US Etsy sellers; on 24 March 2026 OpenAI announced a focus on product discovery and merchant checkout, stating the initial version did not offer the level of flexibility that we aspire to provide
, and re-pointed ACP at product discovery while merchants keep their own checkout. The protocol survived the product that introduced it, which is the useful signal: adoption of a spec and adoption of a surface are not the same thing. Governance remains with the two founding maintainers, and reach is still tied to ChatGPT’s commerce footprint. Specifics such as category coverage, geographic expansion and feed cadence are not published in the spec itself. See what happened to Instant Checkout.
Who should care
Merchants that want their catalogue considered for product discovery in ChatGPT. PSPs and agent builders evaluating the published commerce specifications should distinguish their implementation work from a guarantee of a native ChatGPT checkout. See how to accept payments from AI agents.
Adoption
- OpenAI: AI agent surface (2025-09-29). source
- Stripe: Payment processor (2025-09-29). source
- Etsy: Merchant platform (2025-09-29). source
- Shopify: Merchant platform (2025-09-29). source
- OpenAI: AI agent surface (2026-03-24). source
- Target, Sephora, Nordstrom, Lowe's, Best Buy, The Home Depot, Wayfair: Retailers (2026-03-24). source
- Walmart: Retailer (2026-03-24). source