AI agents — software programs that carry out tasks on behalf of users — are now making payments on their own. They are buying data, computing power, and access to online tools without a human pressing a button for each transaction, and much of that activity is settling in stablecoins.

Crypto's next billion users might not be human. They could be AI agents — and they are already paying with stablecoins, according to a post on X highlighting Coinbase's figures:

Crypto's next billion users might not be human.

They could be AI agents and they're already paying with stablecoins.

Coinbase's x402 has processed:

• 165M+ payments • $50M in volume • Around 99% paid in $USDC

AI agents are buying data, computing power and API access for… pic.twitter.com/zpVXrbYG3J

— MANDO CT 🇮🇪 🇦🇪 🇬🇧 (@MandoCT) August 23, 2026

Coinbase says x402 has processed more than 165 million payments worth a combined $50 million, with roughly 99% of them paid in USDC, a dollar-backed stablecoin and one of the largest in circulation. The activity has drawn a broad set of payments and infrastructure companies: Cloudflare, Mastercard, MoonPay, and Circle — the company that issues USDC — are all building payment tools for AI agents, while card networks are testing their own approaches rather than stepping aside. The market remains early, with most volume consisting of small micropayments averaging around 30 cents per transaction.

How x402 Works

Coinbase built the x402 protocol to handle machine-to-machine payments. It works like a paywall for software: an agent requests a service, receives a price in return, pays, and gets the result. No account creation is involved, and no card details change hands.

The protocol's name is a nod to HTTP 402, a "Payment Required" status code written into the web's technical standards decades ago and left largely unused — a ready-made slot for paid access that machine payments are now starting to fill.

Lincoln Murr, Coinbase's head of AI product, says the typical transaction is around 30 cents. Most payments go to APIs, the connections that let one program request data or a service from another.

Why Stablecoins Are Leading

Stablecoins fit the job well. They work around the clock, move globally, and avoid the 2% to 4% cost that card payments typically carry. When a transaction is worth less than a dollar, those card fees eat too much of the value. Automatically charging fractions of a dollar has been an ambition of internet builders since the web's early days, and card rails designed for larger purchases never made it economical.

Cloudflare, which is building its own wallet system for AI agents, says stablecoins suit the high-frequency, low-value nature of agent payments. Its planned product would work like a corporate card, letting operators set budgets and approved sellers before the agent spends anything.

Circle is testing small USDC payments that confirm quickly and are recorded on a blockchain in batches later. MoonPay has launched a product called PayBox that connects to AI assistants and lets agents use both cards and crypto depending on the merchant.

Coinbase, for its part, has a direct commercial stake in USDC's reach: under a long-standing arrangement with Circle, it shares in the income generated by the reserves backing the stablecoin.

Card Networks Are Still Competing

Mastercard is not stepping back. It is testing a system called Agent Pay for Machines, which uses digital vouchers. An agent owner defines what the software can buy and how much it can spend; sellers check those rules, deliver the service, and claim payment later.

Mastercard says sellers can choose to receive payment in fiat or stablecoin, meaning the buyer and the seller do not have to use the same form of money. The product is in an early access phase, and Mastercard has not released transaction figures.

Visa and DBS Bank ran a trial in February in which an agent bought food and drink using a credit card. The two companies are now looking at online shopping and travel bookings as next steps.

Still Early Days

Coinbase's Murr compared the current state of the market to the Napster and LimeWire era of the internet: the technology works, but the rules and the scale are not yet settled.

The numbers underline the gap. In July, x402 moved about $24 million over 30 days — an amount Visa processes in roughly one minute. Cloudflare's wallets are still in development, and a portion of Coinbase's transaction count may also reflect testing rather than real commerce. Whether those counts turn into sustained commercial use — and whether the card-linked programs publish usage figures of their own — is the clearest signal to watch as the experiments move past trials.

Getting money into an agent wallet in the first place remains a pain point. Coinbase says it is working on making that setup more automatic, including letting an agent set up its own wallet when instructed to do so.