Circle launches Agent Stack to make USDC the default currency for AI agents

Circle just built a financial system where the customers aren’t human. The stablecoin issuer launched its Circle Agent Stack on May 11, a suite of tools that lets autonomous AI agents hold assets, discover services, and settle payments using USDC, all without a person clicking “confirm.” What the Agent Stack actually does The stack has four main components, each solving a different piece of the autonomous-finance puzzle. First, there’s the Circle CLI, a command-line interface that gives developers (and eventually agents themselves) a way to interact with Circle’s infrastructure programmatically. Second, Agent Wallets provide each AI agent with its own USDC-holding account. These wallets come with programmable guardrails, meaning developers can set spending policies, transaction limits, and approval rules before letting an agent loose. Third, an Agent Marketplace acts as a discovery layer where agents can find services offered by other agents. If one AI needs data cleaning and another AI offers it, the marketplace handles matchmaking while USDC handles settlement. Fourth, Nanopayments. These are near-instant, gas-free transactions processed through Circle Gateway that can be as smal...