Circle launched its Circle Agent Stack on May 11, introducing tools designed to let autonomous AI agents hold assets, find services and settle payments in USDC without direct human approval at each step. The suite includes a command-line interface for programmatic access to Circle infrastructure, agent-specific wallets with programmable spending controls, a marketplace for agent-to-agent service discovery, and nanopayments through Circle Gateway that are near-instant, gas-free transactions as small as $0.000001. Circle also said it completed a presale of its ARC token, raising $222 million at a $3 billion valuation. The token is intended to power Arc, a stablecoin-native Layer-1, where transaction fees are paid in USDC instead of a separate volatile native asset. CEO Jeremy Allaire described AI agents as customers in their own right rather than just tools for humans, and the new stack is positioned around that idea by giving software entities wallets, rules-based spending and marketplace access.