ACP vs MCP: Commerce Specifications vs the Context Layer

Short answer: ACP and MCP sit at different layers and increasingly connect. MCP, the Model Context Protocol (Anthropic, 25 November 2024, MIT), is the context layer that connects agents to tools, catalogs and data; it carries no payments. ACP, the Agentic Commerce Protocol (OpenAI and Stripe, 29 September 2025, Apache 2.0), is a commerce specification that powered the original Instant Checkout in ChatGPT; on 24 March 2026 OpenAI announced a focus on product discovery and merchant checkout. Its 17 April 2026 specification adds MCP support. MCP supplies context and tool interoperability; current ChatGPT commerce uses ACP for product discovery.

Criterion	ACP	MCP
Author / steward	OpenAI and Stripe	Anthropic (Linux Foundation since Dec 2025)
Announced	29 Sep 2025	25 Nov 2024
Open-source status	Open source, Apache 2.0	Open source, MIT
What it is	Agent checkout / commerce protocol	Context layer connecting agents to tools and data
Handles payment	Yes (Stripe Shared Payment Token)	No (carries no payments)
Transport	HTTP (OpenAPI); MCP since 2026-04-17	JSON-RPC over stdio or HTTP
Primary use	Product discovery in ChatGPT; checkout on the merchant side	Connect agents to tools, catalogs and data
How they relate	Advertises checkout via MCP tool discovery	ACP, AP2 and x402 connect to or extend it
Notable adoption	OpenAI, Stripe, Etsy, Shopify	Claude, Cursor, Microsoft Copilot, Gemini, VS Code, ChatGPT

Criterion

ACP

MCP

Author / steward

OpenAI and Stripe

Anthropic (Linux Foundation since Dec 2025)

Announced

29 Sep 2025

25 Nov 2024

Open-source status

Open source, Apache 2.0

Open source, MIT

What it is

Agent checkout / commerce protocol

Context layer connecting agents to tools and data

Handles payment

Yes (Stripe Shared Payment Token)

No (carries no payments)

Transport

HTTP (OpenAPI); MCP since 2026-04-17

JSON-RPC over stdio or HTTP

Primary use

Product discovery in ChatGPT; checkout on the merchant side

Connect agents to tools, catalogs and data

How they relate

Advertises checkout via MCP tool discovery

ACP, AP2 and x402 connect to or extend it

Notable adoption

OpenAI, Stripe, Etsy, Shopify

Claude, Cursor, Microsoft Copilot, Gemini, VS Code, ChatGPT

Frequently asked questions

Is ACP the same as MCP?

No. MCP is the context layer that connects agents to tools and data; ACP is a commerce specification. ACP added MCP support in April 2026.

Does MCP handle payments?

No. MCP carries context and tool access, payment and checkout protocols such as ACP, AP2 and x402 connect to or extend it.

Who maintains each?

MCP was created by Anthropic and became a founding technical contribution to the Linux Foundation’s AAIF in December 2025; ACP is maintained by OpenAI and Stripe.