# Agentic Commerce Protocol (ACP)

> An open interaction model and standard for AI agent–driven consumer purchases, co-developed by OpenAI and Stripe. Defines a checkout session lifecycle (create, update, complete, cancel) so agents can discover products, manage carts, and complete purchases on behalf of consumers with human approval at payment. Powers ChatGPT's Instant Checkout and is adopted by merchants including Etsy, Target, and Sephora. Still in beta as of September 2026.

> **Unverified draft.** This entry is seeded but not yet verified against primary sources.

## At a glance

| Field | Value |
| --- | --- |
| Name | ACP |
| Layer | payment-execution |
| Category | framework |
| Status | draft |
| Created by | OpenAI, Stripe |
| Launched | 2025-09 |
| Rails | cards, stablecoins |
| Settlement | Delegates settlement to existing payment providers (Stripe PaymentIntents, Shared Payment Tokens, or merchant-side processors); ACP governs the checkout session lifecycle. |
| Reversible | — |
| Human in loop | required |
| D2C fit | strong |
| B2B fit | moderate |
| Spec | https://github.com/agentic-commerce-protocol/agentic-commerce-protocol |
| Last verified | 2026-09-28 |

## How it works

ACP defines a **checkout session lifecycle** that lets an AI agent assemble an order on a consumer's behalf, present it for human approval, and hand off to a payment provider for settlement — without the agent ever seeing card details.

- **Checkout sessions.** The core abstraction is a checkout session with four operations: **create**, **update**, **complete**, and **cancel**. An agent creates a session when the consumer expresses intent to buy, populates it with product, shipping, and pricing data, and completes it once the consumer approves.
- **Shared Payment Tokens (SPTs).** For Stripe merchants, the consumer's payment method is represented as a scoped, single-use **Shared Payment Token** issued by Stripe. The token lets the agent trigger a charge without accessing the underlying card number, and carries usage and expiration constraints.
- **Delegated Payments.** Merchants that do not use Stripe can implement ACP's Delegated Payments specification, keeping their existing payment processor while still participating in agent-driven checkout flows.
- **Product feeds and carts.** The 2026-04-17 spec revision added **product feed** endpoints, multi-item **cart** management, **order tracking**, **authentication** (OAuth-based merchant linking), and an **MCP binding** so agent tool-calling frameworks can invoke the same checkout operations.
- **Human approval.** ACP requires human confirmation before any payment is executed — the agent assembles and presents the checkout, but the consumer must approve the final charge. This is a deliberate design constraint, not an optional feature.

ACP is **open-source under Apache 2.0** and uses date-based versioning (latest stable: 2026-04-17). It powers **Instant Checkout in ChatGPT** and is integrated by merchants including Etsy, Shopify, Target, and Sephora.

## Tradeoffs

- Requires human approval for every purchase, which limits fully autonomous agent-to-agent commerce use cases.
- Settlement is tightly coupled to Stripe's infrastructure; non-Stripe merchants face additional integration effort via Delegated Payments.
- Currently limited to consumer purchases (D2C); not designed for machine-to-machine or API-access payment patterns.
- As a beta specification, the API surface and session semantics may change between dated revisions.

## Security & limitations

- Shared Payment Tokens scope the agent's access to a single charge with usage and expiry constraints, reducing the blast radius of token compromise.
- The human-approval requirement is the primary security control; if it is bypassed or auto-approved, the agent could execute unauthorized purchases.
- Agent-assembled checkout sessions carry product and pricing data that the consumer must verify — a manipulated session could misrepresent what is being purchased.

## Fits together with

- stripe-mpp

## Sources

1. [Buy it in ChatGPT: Instant Checkout and the Agentic Commerce Protocol](https://openai.com/index/buy-it-in-chatgpt/) — OpenAI, 2025-09-29
2. [Stripe powers Instant Checkout in ChatGPT and releases Agentic Commerce Protocol](https://stripe.com/newsroom/news/stripe-openai-instant-checkout) — Stripe, 2025-09-29
3. [Developing an open standard for agentic commerce](https://stripe.com/blog/developing-an-open-standard-for-agentic-commerce) — Stripe, 2025-09-29
4. [Agentic Commerce Protocol — specification and samples](https://github.com/agentic-commerce-protocol/agentic-commerce-protocol) — OpenAI & Stripe (GitHub)

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_Source: payful.ai — independent editorial reference. Verified 2026-09-28._