Protocols
ACP
ACP, the Agentic Commerce Protocol, lets a merchant run checkout inside an agent such as ChatGPT while the merchant keeps the order, tax, risk, and payment on its own systems. OpenAI's checkout spec defines session endpoints the merchant implements. Payment uses the merchant's processor, optionally with a delegated payment token.
Explanation
The checkout spec requires the merchant to create, update, and complete a checkout session, and to return a full cart each time: items, discounts, shipping, tax, and totals. Optional endpoints retrieve or cancel a session. The merchant emits order webhooks so the agent can follow fulfillment. ChatGPT collects buyer and payment details in its UI. The merchant decides whether to accept the order. OpenAI's key-concepts guide says OpenAI is not the merchant of record.
Delegated payment is a separate spec. The agent asks a payment service provider for a one-time token capped by amount and expiry, then passes that token to the merchant on complete. Stripe's shared payment token is one implementation. None of these calls are a public settlement log. ACP is listed on the protocols page so the coverage is visible, and its volume is not estimated.
Live data
Related terms
Sources
- Agentic Commerce Protocol — Stripe
- Agentic Checkout Spec — OpenAI
- Agentic commerce key concepts — OpenAI
- Delegated Payment Spec — OpenAI
- Shared payment tokens — Stripe
- Agent GDP methodology — Agent GDP