# Key concepts

Learn about the concepts that enable agentic commerce.

Use an agent to manage transactions between a seller and buyers in your AI interface. The agent maintains customer relationships, including preferences, *payment methods* (PaymentMethods represent your customer's payment instruments, used with the Payment Intents or Setup Intents APIs) used for subscriptions, and customer details. This information lets the agent make purchase recommendations directly in the AI interface to improve conversion rates and drive more high-intent purchases.

## Overview

In the AI interface, agents help customers and sellers discover products and complete transactions. Agents issue a [shared payment token](https://docs.stripe.com/agentic-commerce/concepts/shared-payment-tokens.md) (SPT) to manage payment methods.

### Seller

Sellers are individual businesses or platforms made up of multiple sellers, and typically provide e-commerce goods, subscriptions, digital content, or API functions. Use the agent as your sales channel to offer your products.

### AI agent

Your AI agent uses large language models (LLMs) to discover and recommend products for purchase, and can display products in a user interface in response to a prompt. Your customers typically have an account or subscription with your agent. Your agent creates a `Customer` object for each customer and stores their payment information so you can reuse it for future purchases.

### Shared payment tokens

Your agent issues an SPT through the API—a *scoped grant* (Shared Payment Tokens are restricted to a single merchant with usage limits and expiration) of a payment method. As a seller, you can use SPTs with a `PaymentIntent` or outside of Stripe. Stripe grants each SPT to your seller account only, so other sellers can’t use it. For added security and control, SPTs include usage limits and expiration windows. They never contain primary account numbers (PANs) or other raw credentials.

Learn how to create and use [SPTs](https://docs.stripe.com/agentic-commerce/concepts/shared-payment-tokens.md).

## Transaction process

This diagram shows how your AI agents and customers transact, and how you register and process payment methods.
Payment method registration and processing (See full diagram at https://docs.stripe.com/agentic-commerce/concepts)
1. Your customer provides a payment method to your agent through an existing subscription or as a new payment method.
1. Your agent issues an SPT through Stripe. The request specifies the seller that receives the SPT, the transaction amount, and the payment method.
1. Your agent sends the SPT and transaction amount to the seller through your API.
1. You create a `PaymentIntent` using the SPT in your Stripe account, and Stripe processes the transaction.