The shopper is starting to be a program. AI agents are already comparing, deciding, and — increasingly — paying, and the forecasts put hundreds of billions of dollars of purchasing behind them by 2030. But the rails they pay over are fragmenting into competing standards with no common interface. Whoever makes those standards settle through one clean surface wins the plumbing of agent commerce.
The web's checkout was built for a human with a browser, a card, and two hands. An autonomous agent has none of those. When an agent hits a paywall or a purchase, it has no native, standard way to authorize and settle a payment on its own — the entire flow assumes a person clicking a button and typing a card number into a form.
The industry's response, in barely a year, has been a burst of competing standards: Coinbase's x402, Google's Agent Payments Protocol (AP2), OpenAI and Stripe's Agentic Commerce Protocol (ACP), plus Visa Intelligent Commerce and Mastercard Agent Pay from the card networks — Visa and Mastercard launched theirs one day apart, on 29 and 30 April 2025.6 That's the good news and the problem at once. As one landscape analysis puts it plainly, "the market remains fragmented without interoperability standards," and merchants "may need to implement multiple protocols" to reach the agents that want to buy.14
Venture analysis of the stack is blunt about the root cause: there is "no agreed-upon standard for how a human assigns a role and scope to an agent," and authorization, fraud prevention, and liability allocation remain unsolved.13 Deciding to buy is close to solved. Paying — cleanly, across rails, at machine speed and machine cost — is not.
Three numbers frame it: how much purchasing will run through agents by 2030, how fast AI-driven shopping traffic is already growing, and the machine-native settlement volume proving it's real today.
The agents themselves are a market too: the global AI-agents software market is forecast to reach USD 50.31 billion by 2030 at a 45.8% CAGR.12 Every one of them is a potential buyer that needs a way to pay.
Every major AI lab and payment network now has an agent-payment play. They overlap, they compete, and — tellingly — they've already started leaning on each other. Here's who built what.
Reuses the dormant HTTP 402 Payment Required status code to embed USDC stablecoin payments directly into a web request — so an agent hitting a paywall attaches a signed payment header and continues, no account, no checkout page.1
It is the only agent-payment standard with live, high-volume settlement, and it's now governed by the x402 Foundation under the Linux Foundation.2
The Agent Payments Protocol represents each purchase as cryptographically signed Mandates (Intent, Cart, Delegated Authority), solving who authorized what. Announced with 60+ partners including Mastercard, Amex, PayPal, and Coinbase.3
Tellingly, it's payment-agnostic and supports stablecoins via an x402 extension — the standards are already trying to compose, not just compete.
The Agentic Commerce Protocol powers Instant Checkout in ChatGPT, using a Shared Payment Token so the agent pays without exposing the buyer's card credentials. Live with Etsy, expanding toward a million-plus Shopify merchants.4
It's the demand-side proof: agents are already buyers inside the world's most-used AI product.
Visa Intelligent Commerce (partners: OpenAI, Anthropic, Microsoft, Stripe) and Mastercard Agent Pay (partners: Microsoft, IBM, Braintree) bind tokenized card credentials to a specific agent, merchant scope, and consent policy.6
They keep settlement on existing card rails — competing head-on with the stablecoin approach for the same agent checkouts.
The forecasts assume agents can pay smoothly. The reality is a fragmented field where each rail speaks its own dialect, and a builder wanting to accept agent payments faces a choice between betting on one standard or integrating all of them.
Express Protocol is our open-source SDK for agentic onchain commerce. Its design principle is four standards, one interface: mint, trade, and manage NFTs and real-world assets across ERC-721, ERC-1155, and ERC-404 — and settle agent payments through an x402 module built on Coinbase's HTTP 402 stablecoin standard — all from a single, consistent developer surface.
That directly addresses the gap above. Instead of asking a builder to re-implement payments for every emerging protocol, Express treats x402 as a first-class settlement rail inside the same interface used to handle assets: an agent hits a resource, x402 attaches a signed USDC payment, and it settles onchain — no checkout page, no card form, no seat at a human's browser. As the payment landscape keeps fragmenting, the value is in the abstraction: write to the interface, not the rail.
pandora-express has been live on npm since February 2022.See how Express Protocol ships x402 as a first-class rail — four standards behind one SDK interface, so autonomous agents transact onchain without a checkout page.