Stripe and OpenAI release the Agentic Commerce Protocol with Instant Checkout
A checkout-session protocol for agents, distinct from x402’s HTTP 402 challenge.
protocol
Agentic Commerce Protocol
Open checkout-session protocol co-developed by Stripe and OpenAI for in-chat and agent-led retail checkout. Distinct from x402 HTTP 402 metering.
Machine: /v1/intelligence/entity/acp · Graph: /v1/graph/entities/acp
Graph relationships
- evt-acp-docs-home
- evt-acp-docs-sellers
- evt-openai-instant-checkout-2025-09-29
- evt-stripe-openai-acp-2025-09-29
- openai
- stripe
Timeline
OpenAI opens Instant Checkout and publishes ACP as an open standard
ChatGPT becomes a commerce client. Merchants keep their processor.
ACP docs define merchant checkout-session REST endpoints
Five HTTPS JSON endpoints, not an HTTP 402 challenge.
ACP documentation home states the job to be done: programmatic checkout
Agents render checkout state; sellers keep processors. Not HTTP 402.
Agent commerce protocols proliferate beyond crypto-native stacks
Stripe ACP, Visa Intelligent Commerce, MPP and x402 now sit in one landscape.