AI Agents Are Paying Their Own Bills With USDC, and Payments Giants Are Racing to Catch Up — BigGo Finance

For years, crypto executives speculated about onboarding the next billion users. The assumption was that those users would be people—perhaps the underbanked in developing economies or those fleeing currency instability. The reality now emerging is different: the next wave of crypto users may not be human at all.

AI agents—autonomous software programs capable of executing multi-step tasks—are increasingly transacting on behalf of their users. To complete tasks, these agents often need to purchase data, computing power, or access to online tools. And in the nascent machine-to-machine economy, dollar-denominated stablecoins, particularly USDC, have taken an early lead.

Coinbase’s x402 protocol, a payment system designed specifically for AI agents, has processed more than 165 million payments worth a combined $50 million, according to the company. Lincoln Murr, Coinbase’s head of AI product, estimates roughly 99% of those payments use USDC. The average transaction size: about 30 cents.

“The primary product-market fit today is machine-to-machine payments from agents to APIs,” Murr said. “Given the velocity of these AI agents and how quickly they move across the internet, we need a standard way for them to pay for things.”

Most of those payments are not for shoes or hotel bookings. They are microtransactions—often a few cents at a time—for application programming interface calls, data, inference, and content. One software agent might buy from dozens of services while completing a single task, replacing a bundle of subscriptions with a stream of tiny purchases.

How Machine-to-Machine Payments Work

x402 functions essentially as a paywall for software. When an agent requests data or a service, a seller responds with a price and payment data. The agent pays, and once the payment is verified, the results are released. The name derives from “402 Payment Required,” a web status code that has existed for decades but was rarely used.

The protocol’s April update counted more than 480,000 agents in the x402 ecosystem. An Artemis dashboard shows the majority of transactions occur on Base, Coinbase’s layer-2 blockchain. Murr estimated that 25% to 30% of transactions may have been generated by users trying to climb public leaderboards rather than buying actual services—a sign of how early-stage the ecosystem remains.

Stablecoins have structural advantages for this use case. They operate around the clock, settle globally, and avoid the 2% to 4% card acceptance costs that make sub-dollar transactions economically awkward. A merchant or payment company can also cover blockchain fees, meaning the agent does not need to hold another cryptocurrency just to transact.

“Stablecoins are particularly well suited to the kinds of transactions we expect AI agents to make at first, essentially lots of very small, high-frequency payments for things like API calls, data, inference, and content,” said Stephanie Cohen, Cloudflare’s chief strategy officer.

Cloudflare, the cloud infrastructure company, is building its own agent payment rails. Its Cloudflare Wallets product is designed to work more like a corporate card than an unrestricted crypto wallet. An operator deposits money into a main wallet, gives an agent a smaller allowance, and sets rules around budget, approved sellers, and maximum purchase size. The planned Monetization Gateway would allow websites to charge for an individual page, dataset, or online tool rather than requiring a subscription.

Circle is testing a similar model with its Nanopayments product, which confirms small USDC payments quickly and then records their combined value on a blockchain later. MoonPay launched PayBox on July 29, connecting to Claude or ChatGPT and storing access to both cards and crypto wallets. Users can approve each purchase with a passkey or let an agent spend within preset limits.

Card Networks Fight Back

Mastercard is not conceding the agentic commerce market to stablecoins. The company is piloting Agent Pay for Machines, a voucher-based system in which an owner defines what an agent may buy and how much it can spend. A seller checks those rules, provides the service, and claims payment later. The credentials are called Verifiable Vouchers.

“Execution can happen continuously in real time, while settlement follows a more efficient batched model,” said Sapan Mandloi, Mastercard’s executive vice president of tokenization and checkout services.

The seller could choose to receive payment in fiat currency or an accepted stablecoin, meaning buyer and seller do not need to use the same form of money. “Our view is that agentic commerce will be a multi-rail environment,” Mandloi said. “We see stablecoins as complementary to existing payment systems, not a replacement for them.”

Cards maintain a significant advantage: they already work at millions of merchants and come with established systems for credit, refunds, and dispute management. In February, DBS Bank and Visa demonstrated an agent purchasing food and drink using DBS/POSB credit and debit cards. The partners are now exploring online shopping and travel bookings.

Those purchases look different from a 30-cent API call. They are larger, occur at merchants that already accept cards, and come with consumer protections. For micropayments, the economics of fraud protection change the calculus entirely.

“For micropayments, mitigating fraud can often cost more than the value of the fraud,” Cohen said. “For larger payments, card rails remain a better fit given fraud and other protections.”

The Guardrails Problem

Moving money is only part of the challenge. An agent can misunderstand an instruction, choose the wrong service, or obey a malicious prompt even when the payment itself works exactly as designed. That makes control over the software at least as important as the rail carrying the money.

Coinbase, Cloudflare, Mastercard, MoonPay, and wallet company Turnkey are converging on the same first line of defense: restrict the agent before it acts. Their systems use combinations of capped balances, approved sellers, transaction limits, and human approval for sensitive actions.

“Agents need to be granted scoped permissions on a wallet to prevent damages,” said Bryce Ferguson, Turnkey’s co-founder and CEO. “You can almost think of this like a self-driving car. In the early days, self-driving cars needed somebody with their hands on the steering wheel to make sure nothing went wrong.”

Ferguson drew a dividing line between markets built for software and the ordinary consumer economy. “Autonomous agents don’t need crypto wallets, strictly speaking,” he said. “They can use credit cards and bank credentials, but that will likely be for old-school purchases like a pair of shoes or groceries. Crypto is ultimately a much better rail for purchasing a single API call or a single piece of data.”

Who bears responsibility when the machine follows the rules and still makes the wrong purchase remains unsettled. Coinbase’s Murr said agent failures are part of the reason x402 currently focuses on microtransactions. “If my agent messes up and wastes 10 cents, I’m not going to litigate over that,” he said. “However, as we move into larger purchases, we want to add support for escrows and refunds.”

A Nascent Market

For all the activity, the market remains far behind its most aggressive predictions. x402 moved about $24 million over 30 days in July—roughly what Visa handles in one minute. Cloudflare’s wallets are still in development. Mastercard’s solution is in early access. MoonPay has not released usage figures. Turnkey says activity is not yet at scale.

Murr compared the current landscape to the “Napster/LimeWire era” of agentic payments, or the “QR code scanner/flashlight app” phase of mobile applications. “People are experimenting, and we know it’s the future, but we’re still figuring out the exact mechanics,” he said.

There is also a basic hurdle in getting money into an agent’s hands in the first place. “Getting set up with the wallet is still a massive pain point,” Murr said. Coinbase is working on fiat onramps and seamless setup flows. “Ultimately, you should just be able to tell your agent, ‘Set up a Coinbase agentic wallet for me,’ and it will go search the internet, download the wallet, and prompt you to sign in via email and fund it with crypto.”

The future market for agentic payments will probably use several methods. An agent may see one price and one set of spending rules, with the buyer paying by card, bank account, or stablecoin and the seller choosing how to receive the money. Stablecoins, however, have something more than a theoretical fit: measurable usage and a large share of an early network built specifically for software.