Glossary
All important terms related to Agentic Commerce — clearly explained.
A
A2A — Agent-to-Agent Protocol
Google's protocol for communication between AI agents. Enables multi-agent workflows where specialized agents collaborate.
ACP — Agentic Commerce Protocol
Open standard by OpenAI and Stripe for transactions between AI agents and merchants. Defines Product Feeds, Checkout API and Delegated Payment.
Learn more →Agent Experience
The quality of interaction between an AI agent and a digital system. Increasingly replacing User Experience as the optimization target in Agentic Commerce.
Agent Pay — Mastercard Agent Pay
Mastercard's system for AI agents in the payment flow that automatically initiates and manages transactions.
Learn more →Agentic Checkout
A checkout process executed programmatically by an AI agent instead of by a human through a web interface.
Learn more →Agentic Commerce
Commerce model in which autonomous AI agents make purchasing decisions and execute transactions on behalf of users.
Learn more →AP2 — Agent Payments Protocol
Google's universal payment framework for AI agents, based on digitally signed mandates.
Learn more →Autonomous Shopping
The highest level of Agentic Commerce: AI agents purchase without explicit approval per transaction, based on predefined rules.
AI Agent
An autonomous AI system that pursues goals, creates plans and executes actions in the real world — as opposed to a chatbot that only responds to queries.
Learn more →B
Business Agent — Google Business Agent
Google's AI system that allows customers to chat directly with brands and merchants in Google Search. Based on the Universal Commerce Protocol (UCP).
Learn more →C
Checkout API
REST-based interface in ACP with four endpoints: CreateCheckout, UpdateCheckout, CompleteCheckout and CancelCheckout. Enables AI agents to manage shopping carts programmatically.
Learn more →Conversational Commerce
Predecessor of Agentic Commerce: shopping via chat interfaces (WhatsApp, Messenger), but still with human control at every step.
Learn more →D
Delegated Payment
Payment method where an agent uses tokenized credentials (e.g., SharedPaymentToken) to pay on behalf of the user.
Learn more →Discovery
The phase in the commerce lifecycle where products are found and compared. Standardized in UCP, covered via the Product Feed Spec in ACP.
Learn more →F
Function Calling
The ability of modern LLMs to call external functions and APIs during a conversation. Technical prerequisite for an agent to search products, create carts and trigger payments.
Learn more →G
GEO — Generative Engine Optimization
Optimization of content and product data for AI-powered search systems and agents, rather than just for traditional search engines.
Learn more →H
Headless Commerce
E-commerce architecture with separated frontend and backend connected via APIs. Ideal foundation for Agentic Commerce since the API infrastructure already exists.
Learn more →I
Identity Linking
In UCP: Linking a user account at the AI agent with an existing customer account at the merchant. Enables personalized pricing, loyalty points and order history.
Learn more →Instant Checkout
OpenAI's feature in ChatGPT that allows users to purchase products directly in the chat. First production implementation of ACP.
Learn more →L
LLM — Large Language Model
Large language model such as Claude (Anthropic), GPT (OpenAI) or Gemini (Google). Technological foundation for AI agents in Agentic Commerce — understands natural language, plans actions and calls APIs.
M
Mandates
In the AP2 protocol: Digitally signed authorizations that define what an AI agent may spend on behalf of the user — including amount limits, merchant categories and validity periods.
Learn more →MCP — Model Context Protocol
Open protocol by Anthropic that connects LLMs with external tools and data sources. The 'USB port' for AI — a shop provides an MCP server, any agent can use it.
Learn more →Merchant of Record
The merchant who is legally responsible for a transaction. With ACP and UCP, the merchant remains MoR — not the AI platform. Pricing, fulfillment and customer service remain with the merchant.
Multi-Agent System
Architecture in which multiple specialized AI agents collaborate: a research agent searches, a comparison agent evaluates, a checkout agent purchases.
Learn more →P
Product Feed
Structured dataset with product information (prices, availability, variants, images) that AI agents can retrieve in machine-readable format. Comparable to Google Shopping Feeds.
Prompt Injection
Attack vector where manipulated inputs lead an AI system to unintended actions. A risk in Agentic Commerce: manipulated product data could lead an agent to make erroneous purchases.
Learn more →R
Rufus
Amazon's AI shopping assistant, integrated into the Amazon app. Advises on purchase decisions, compares products — but only within the closed Amazon ecosystem.
Learn more →S
Schema.org
Standard for structured data on web pages, initiated by Google, Microsoft, Yahoo and Yandex. Essential in Agentic Commerce for AI agents to correctly interpret product information.
Learn more →SharedPaymentToken
Tokenized payment information in ACP/Stripe: single-use, bound to a specific amount and merchant, time-limited. Real card data is never transmitted.
Learn more →Shopping Graph
Google's database with billions of product listings from across the web. Foundation for Google Shopping and the Business Agent — the most comprehensive machine-readable product database in the world.
T
TACP — Trusted Agentic Commerce Protocol
Forter's protocol for customer data retention and fraud prevention in Agentic Commerce. Uses JWE encryption to securely pass customer data to merchants.
Learn more →Tool Discovery
In MCP: The ability of an agent to automatically detect which functions an MCP server provides. An agent 'discovers' that a shop offers product search, cart and checkout.
Learn more →U
UCP — Universal Commerce Protocol
Open standard by Google and Shopify for the entire commerce lifecycle: Discovery, Identity Linking, Checkout and Post-Purchase Management.
Learn more →X
x402
Open micropayment protocol by Coinbase, based on the HTTP 402 status code ('Payment Required') and stablecoins. Enables agents to pay for API access and digital content.
Learn more →Z
Zero-Click Commerce
Purchase process without a manual click by the user. The ultimate goal in Agentic Commerce: the agent detects a need, finds the best product and purchases it — the user confirms at most by voice or gesture.