Agentic commerce glossary

Plain, sourced definitions of the terms used across this site. Deep-link any entry.

Agentic commerce: Online commerce in which AI agents discover, decide and complete purchases on a person's behalf, rather than the person clicking through a storefront themselves.
Agentic checkout: The step where an AI agent finalizes a purchase with a merchant, passing order and payment details over a protocol such as ACP, while the merchant remains merchant of record.
ACP (Agentic Commerce Protocol): Open standard co-developed by OpenAI and Stripe (announced 29 Sep 2025, Apache 2.0) that powers Instant Checkout in ChatGPT.
AP2 (Agent Payments Protocol): Open, payment-agnostic protocol announced by Google on 16 Sep 2025 to authorize and execute agent-led payments; an extension of A2A and MCP.
MCP (Model Context Protocol): Open standard from Anthropic (25 Nov 2024, MIT, donated to the Linux Foundation in Dec 2025) that connects AI agents to tools and data. The context layer of the stack.
x402: Open payment standard from Coinbase (6 May 2025, Apache 2.0) that carries native stablecoin payments over HTTP using the 402 status code.
A2A (Agent2Agent): Protocol for communication between AI agents; AP2 is designed as an extension of A2A.
Instant Checkout: The in-chat purchase experience in ChatGPT, powered by ACP and built with Stripe, that lets users buy from merchants without leaving the conversation.
Shared Payment Token (SPT): A Stripe payment primitive that lets an application like ChatGPT initiate a payment scoped to a specific merchant and cart total without exposing the buyer's credentials.
Facilitator (x402): A service that verifies and settles x402 payments on-chain so that sellers do not need to run their own blockchain infrastructure.
Merchant of record: The entity legally responsible for a sale (payment, tax, fulfillment, support). Under ACP the merchant stays merchant of record; the agent only relays information.