Circle

Circle publicly ran an experiment called Steve: 8 autonomous AI agents, each with its own USDC wallet, paid for data on their own via the x402 protocol and placed bets on the 2026 World Cup on Polymarket - with no human reviewing in real time. Writing from the front lines of building agentictrade, the author breaks down why the agent economy matters and why a spending cap is the key design that makes it safe for AI to spend money.

Circle releases Agent Stack with four tools - Agent Wallets, Marketplace, CLI, and Nanopayments - enabling AI Agents to autonomously hold USDC and complete payments. The x402 protocol allows Agents to automatically sign payments when APIs request payment, then receive data after on-chain settlement, fully automating micro-payments.