For all the hype about AI agents transacting on their own, one figure stands out: USDC, the dollar-pegged stablecoin issued by Circle, settles 99% of payments on x402, the leading protocol for agent-to-agent commerce.
In a report published Aug. 7, Shoal Research analysts Paul Timofeev and Gabe Tramble argue Circle is uniquely positioned to bank the coming machine economy, because agents need what humans never did: programmable, sub-cent settlement at high velocity.
"Every layer of today's payment stack assumes a human at both ends of every payment," the Shoal analysts write, "which for most of human history has been true, up until recently."
But dominance in a nascent niche is not the same as owning it, and the report is blunt about the challenge Circle now faces in defending its early lead in agentic payments.
Stripe, a major player in traditional payments, is building a rival stack that treats USDC as one option among many, while Tether's USDT dwarfs USDC in raw supply. As the authors put it: "Even on its own asset, Circle does not own the point where agent payments clear."
The competitive field
Coinbase built x402 and runs its default settlement point, controlling both the developer relationship and the clearing path.
Stripe co-authored the Machine Payments Protocol, "deliberately payment-method-agnostic," and can "route an agent payment around stablecoins entirely onto a card."
Tether commands ~$183B in USDT supply versus USDC's ~$73B, betting instead on offline, on-device "sovereign agents."
PayPal, Western Union and Polygon have all launched competing stablecoin rails.
(HOW AI WAS USED IN THE PRODUCTION OF THIS PIECE: I wrote the first draft of this story on Claude Desktop using a custom skill and prompt. I then used Distro Publisher, our MCP server, to file a draft directly to DeAI News on DistroVerse, our web app. I then edited the story using our native (non-AI) DistroVerse story editing interface and checked the facts prior to publication. I used ChatGPT to create the infographic.)