Circle stated that not all AI agents use stablecoins, but when agents need to transact with stablecoins, USDC is the preferred choice. Chief Strategy Officer Dante Disparte discussed the intersection of blockchain, AI, and digital dollars.

The company emphasizes this claim with the launched Circle Agent Stack: agent wallets, agent marketplace, command-line tools, nano payments powered by Circle Gateway, and Circle Skills. Agents can hold and spend USDC within limits, whitelists, and time windows, discovering and paying for services through protocols like x402. Nano payments allow for a minimum single transaction limit of $0.000001, with no gas fees on the same chain and cross-chain Gateway fees around 0.5 basis points.

The official product page states that USDC accounts for about 99.8% of x402 transaction value; other statistics indicate that since May 2025, USDC has made up about 99.6% of x402 settlement amounts, and Circle claims that USDC constitutes about 98.6% of agent payment volumes. These shares correspond to agent traffic that has chosen the stablecoin route, which remains small. The agent marketplace has expanded from over 600 services at launch to about 900, covering more than ten chains. Services like Venice for inference and generation have been integrated, allowing agents to call USDC per use without traditional key subscriptions.

CEO Jeremy Allaire also stated, "The machines have already chosen their money." Product Technology Officer Nikhil Chandhok positioned USDC as a programmable, always-on, near-zero-cost settlement asset. Circle also launched the Layer-1 network Arc for institutions and agents, using USDC as native gas, completing a private token sale of about $222 million, with a network valuation of around $3 billion and an initial supply of 10 billion tokens. The circulating market cap of USDC is still lower than USDT, but it leads in on-chain transaction counts and some trading volumes.

The competitive landscape has opened up. Coinbase's x402, Stripe-supported machine payment protocols, Google's AP2, and the Open USD Alliance are all vying for the agent settlement layer. Open USD, involving Stripe, Coinbase, Mastercard, Visa, and BlackRock, shares reserve earnings with partners, directly challenging Circle's model of profiting from treasury bond interest. Circle's stock price fell over 17% in a single day after the alliance was disclosed.

In terms of market mechanisms, the purchase is that developers default agent expenditures to USDC, while the sale involves reserve interest plus nano payment and cross-chain fees. Funding is shifting from manual subscriptions and minimum credit card charges to machine-to-machine micro-settlements. Beneficiaries are Circle and service providers integrated with x402; those under pressure are traditional payment networks that charge annual fees per account and new stablecoin alliances that pass earnings to merchants. The event driver is the company's use of executive messaging to reinforce the mindset of "defaulting agents to dollars," rather than new regulatory approvals.

Legislation like the GENIUS Act provides compliance frameworks for issuers, while limits and whitelists for agent wallets make machine expenditures auditable corporate controls. High traffic shares do not equate to a scaled agent economy.

Source: Public Information