# Agentic Commerce Protocol (ACP)

> An open standard, maintained by OpenAI and Stripe, that connects buyers, their AI agents and merchants so a purchase can complete inside a conversation.

_The Agentic Web Lexicon · /glossary/acp · [JSON](/api/glossary/acp) · [all The Agentic Web Lexicon](/glossary)_

- **term:** Agentic Commerce Protocol (ACP)
- **category:** commerce
- **short_def:** An open standard, maintained by OpenAI and Stripe, that connects buyers, their AI agents and merchants so a purchase can complete inside a conversation.
- **long_def:** ACP defines an interaction model for in-conversation checkout — the standard behind ChatGPT's Instant Checkout. Maintained jointly by OpenAI and Stripe as Founding Maintainers under the Apache 2.0 license, it uses date-based (YYYY-MM-DD) versioning, with OpenAI and Stripe providing the first reference implementations.
- **see_also:** agentic-commerce, x402, ap2
- **etymology_origin:** Introduced alongside ChatGPT Instant Checkout (29 September 2025); the specification is maintained by OpenAI and Stripe as Founding Maintainers under Apache 2.0, with date-based (YYYY-MM-DD) versioning.
- **related_to:** agentic-commerce, x402, ap2, agent-as-buyer
- **contrast_with:** Unlike AP2, a payment-authorization protocol, ACP is the broader checkout interaction model between an agent and a merchant — it governs how the purchase happens in-conversation, and can settle through underlying payment rails.
- **example:** OpenAI and Stripe launched the Agentic Commerce Protocol with ChatGPT Instant Checkout on 29 September 2025, going live with Etsy on launch day.
- **source:** https://github.com/agentic-commerce-protocol/agentic-commerce-protocol
- **status:** emerging
- **why_it_matters:** ACP is how a merchant exposes its catalog and checkout to ChatGPT and other agents directly; speaking it is the path to selling inside an AI conversation.
- **sameAs:** —
- **bridge_entity:** protocols/payments/acp
- **last_verified:** 2026-06-15
- **md_twin:** /glossary/acp.md