AI Agent Payments Drive USDC to Dominance in the Machine Economy

Article by Baihua Blockchain

The market has chased AI coins for three years, but the one actually used by AI may not have been on most people’s radar from the start.

The most counterintuitive part is that AI-themed coins like FET, TAO, and RENDER are not actually used by the AI agents running on the network themselves.

AI agents that truly operate on the network don’t use FET to buy GPU compute, don’t use TAO to call APIs, and don’t use RENDER to pay model royalties. An AI agent can send hundreds of payments per second—credit card fees of 2.9% plus $0.30 per transaction simply can’t scale. AI agents require sub-second settlement, while ACH transfers still operate on a three-day cycle. AI agents don’t view screens or click buttons—any workflow requiring human confirmation of payment is immediately obsolete.

Everything claiming to be an AI token is absent from the real AI economy.

But money is still flowing wildly between machines, at a volume of hundreds of millions of dollars per day. What exactly is flowing?

Who exactly is the AI token?

Not FET, not TAO, and not RENDER.

It's USDC.

In 2025, Coinbase partnered with Circle and Google to do something strange: they dug up something that had been buried for thirty years.

HTTP 402.

Several HTTP status codes are commonly encountered: 200 means success, 404 means not found, and 500 means the server crashed. But the code 402 has remained unused since the protocol was first drafted in the 1990s; its official name is "Payment Required." The designers originally reserved it, anticipating that one day the internet would need a native payment mechanism.

For thirty years, no one used it—until the x402 protocol in 2025 activated it for the first time.

It’s simple. Previously, an AI agent accessing a paid API had to register an account, obtain an API key, link a credit card, and have a human confirm the setup. Now, it’s unnecessary. The agent sends a request, and the server immediately responds with a 402 status code containing payment metadata—clearly specifying the amount, the收款 address, and the supported blockchain. Upon seeing the 402, the agent’s wallet automatically signs a USDC transfer, resends the request, and completes the process in under two seconds.

No account, no API key, no human verification.

Jeremy Allaire provided a figure: within the next three to five years, billions of AI agents will be running on the internet, continuously sending payments 24/7. This number may sound exaggerated, but if you accept the premise that machines operate at thousands of times the frequency of humans, it becomes immediately reasonable.

A technical employee might sign 10 contracts in a day, while an agent might sign 10 contracts in a second.

After the x402 protocol activation, USDC's identity has changed. It is no longer just a "stablecoin" or a tool for trading pairs among crypto traders. It has become a protocol primitive of the machine internet, positioned alongside TCP/IP and HTTP.

In simple terms, the internet has evolved from a network for transmitting information between people to a network for transferring value between machines—and the universal currency used for this transfer is USDC.

Do you think this is just a narrative? The data has already voted.

Circle’s 2026 data: Over 98% of agent-driven payments used USDC. Not 60%, not 80%, but 98%. The average payment was $0.31—an amount too small for a human to initiate individually, since even a coffee at Starbucks starts at $4. These penny-scale transactions can only be happening between machines.

Circle built its own chain called Arc, specifically designed for stablecoin finance. The cost per transaction on the Arc chain is not the frequently cited $0.00001, but approximately $0.01.

What truly reduces the cost of transferring USDC to the level of $0.00001 is not the gas fee for a single transaction on the Arc chain, but rather aggregating transactions off-chain and settling them collectively on-chain.

Compare: credit cards charge 2.9% plus $0.30; bank wire transfers cost $15 to $50. The fixed fee component of traditional payments is an order of magnitude higher than the total amount of a single machine transaction. For an AI agent to send a $0.31 payment through the traditional banking system, the fee alone would cost it nearly 100 times the value of the payment itself. This isn’t just “friction”—it’s “infeasible.” What stablecoin rails truly solve isn’t about reducing every on-chain cost to near zero, but rather enabling machine-level micropayments for the first time through programmable settlement and batch aggregation.

What about those truly called AI tokens?

Coins like FET, TAO, and RENDER are virtually absent from AI agent wallets; they sit in speculative traders’ contract accounts, swinging daily by 5% to 10%. If an AI agent were to use TAO to pay for compute rental, it might afford 1,000 hours today, only 900 hours tomorrow, and 1,100 hours the day after. It cannot create budgets, perform financial planning, or enter into any contracts with external vendors that have price anchors.

What’s more ironic is that those coins bearing the name "AI" don’t move a single cent in the real AI economy.

They are meant for humans to trade, not for machines.

A "stablecoin" has become the lifeblood of machine civilization.

Some might say that FET and TAO aren't completely useless.

Yes, they have their use cases—but that use case has never been "money"; it's "commodity."

HashKey provided a more precise dichotomy in a Web3 report: AI tokens are the smallest semantic unit of computational power consumption, similar to electricity and gas; blockchain tokens are the most programmatic unit of value flow, akin to cash.

TAO is the electricity flowing through the outlets in your home; USDC is the cash in your wallet. You use TAO to train models, allocate computing power, and run inference—just as you use electricity to light up a room or boil a kettle. But you wouldn’t use a kilowatt-hour to pay at the grocery store; you’d use cash.

Inside its own internal network, the AI agent might use TAO to coordinate computational tasks. But as soon as it steps outside—renting AWS servers, ordering plush toys from Amazon, or paying a human freelancer for their work—it only recognizes USDC. After all, AWS doesn’t accept TAO, Amazon doesn’t accept FET, and human workers won’t take RENDER as payment.

The two sides of the balance sheet are entirely different things.

At the end of 2024, Stripe spent $1.1 billion to acquire Bridge, a stablecoin infrastructure company. The figure attracted little attention at the time, but in hindsight, it signaled a surrender by a traditional payment giant to machine payments. A company that had relied on credit card fees for two decades used $1.1 billion to buy a ticket to the machine economy.

VanEck then made a prediction: by 2027, daily on-chain trading volume driven by AI agents will reach $5 billion, with a compound annual growth rate exceeding 120%.

$50 billion per day amounts to $1.8 trillion annually.

What does this number mean? Currently, the total volume of global cross-border payments via SWIFT is approximately $5 to $6 trillion per day. In other words, within three years, automated transfers between AI agents could account for one-third of all global cross-border payments.

And nearly all of this $1.8 trillion will go through USDC.

The market has misunderstood the story behind AI tokens.

True AI tokens are not FET, TAO, or RENDER—they are speculative tools betting on the future appreciation of some AI infrastructure. The true AI token is USDC, the actual fiat-backed currency AI agents use daily for settlements.

One is a narrative, the other is a pipeline. One tells stories to humans, the other runs production for machines.

How does the pendulum swing? In 2022, everyone believed anything labeled with AI was valuable; in 2024, everyone thought anything labeled with AI was a bubble; by 2026, the real winner turned out to be a "stablecoin." Wall Street’s pricing logic has always lagged behind technological reality—and this time is no different.

The internet didn’t kill traditional commerce; traditional commerce learned e-commerce. Cryptocurrency didn’t overthrow the dollar; the dollar learned to go on-chain. AI didn’t create a new currency; AI chose the oldest one—the dollar—and used its programmatic version.

Does the AI token you bought actually have AI using it?

Real AI tokens don't need the word "AI" in their name.