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Agentic Commerce Protocol (ACP)
Open standard co-developed by Stripe and OpenAI (Apache-2.0, September 2025) for completing a purchase against a merchant that stays the merchant of record. The merchant exposes agent-facing REST or MCP endpoints (create, update, complete, and cancel checkout) over a product feed; the agent pays with a Stripe-issued Shared Payment Token scoped to a single merchant and cart total, so the agent never sees the buyer's card credentials. It launched as the standard behind ChatGPT Instant Checkout with Etsy sellers and Shopify merchants. Distinct from `model-context-protocol`: MCP is a general tool-calling transport, whereas ACP is a specific checkout contract that can ride over MCP or plain REST.
In 30 seconds
- What
- Agent browses merchant product feed, builds cart via REST/MCP endpoints, completes purchase with Stripe-scoped token that never exposes buyer credentials.
- When to use
- Autonomous shopping where an agent must complete transactions while merchant retains fulfillment, support, and merchant-of-record status.
- Watch out
- Agents may over-commit to purchases before user confirmation, or fail gracefully if cart totals shift between create and complete calls.
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Agentic Commerce Protocol (ACP): Overview
Open standard co-developed by Stripe and OpenAI (Apache-2.0, September 2025) for completing a purchase against a merchant that stays the merchant of record. The merchant exposes agent-facing REST or MCP endpoints (create, update, complete, and cancel checkout) over a product feed; the agent pays with a Stripe-issued Shared Payment Token scoped to a single merchant and cart total, so the agent never sees the buyer's card credentials. It launched as the standard behind ChatGPT Instant Checkout with Etsy sellers and Shopify merchants. Distinct from `model-context-protocol`: MCP is a general tool-calling transport, whereas ACP is a specific checkout contract that can ride over MCP or plain REST.
- Merchant stays merchant of record and keeps fulfillment and support
- Agent-facing REST or MCP endpoints: create, update, complete, cancel checkout
- Product feed lets the agent browse the catalog and build a cart before payment
- Shared Payment Token scoped to one merchant and one cart total
- Agent never sees raw card credentials, so PCI scope stays with the processor
- Apache-2.0 open standard; roughly one line of code for existing Stripe merchants
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References
The papers, specifications, and repositories this pattern is based on.
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