Circle launches Agent Stack to use USDC for AI agent payments

Circle launched the Agent Stack on May 12, 2026, a suite of financial infrastructure tools designed for autonomous software to hold USDC, discover services and execute micropayments. The package includes agent wallets, an agent marketplace, a command-line interface and pre-built Circle Skills for payment and treasury tasks.

Agent Wallets are permissionless, policy-controlled accounts that allow software agents to hold and spend USDC within guardrails set by human principals. The marketplace is a curated directory where agents can programmatically find, evaluate and pay for services. Circle CLI provides a command-line interface for developers and agents to interact with Circle’s platform. Circle Skills are pre-built financial actions for common payment and treasury operations.

Nanopayments are handled by Circle Gateway and allow gas-free USDC transfers as small as $0.000001, or one-millionth of a dollar, at machine speed. Circle said the nanopayment capability is intended to make per-API-call and per-data-request billing economically practical, avoiding the cost and latency of card and ACH systems that were not built for high-frequency, sub-cent transactions.

Circle described the Agent Stack as protocol-agnostic software that can run across existing networks rather than requiring a single standard. The company reported $8.3 billion in annualized transaction volume as of March 31, 2026, and disclosed that USDC accounted for 63% of stablecoin transaction volume in Q1 2026.

The announcement arrives amid competing infrastructure offerings. In the prior week, Amazon Web Services introduced Bedrock AgentCore Payments in partnership with Coinbase and Stripe, and the Solana Foundation and Google Cloud released Pay.sh, an open-source gateway for per-request agent payments on Solana. Other protocols in the market include Coinbase’s x402, Stripe-backed Tempo’s Machine Payments Protocol and Google’s AP2.

Regulatory developments are part of Circle’s public framing of the product. Circle referenced the CLARITY Act discussions in Washington, noting the legislation preserves activity-based rewards while restricting passive yield. The company pointed to its regulatory relationships as issuer of a regulated stablecoin when describing compliance advantages it expects to bring to agent payments.

Circle also announced a $222 million presale of ARC tokens at a $3 billion fully diluted valuation, with BlackRock listed among participants. The company described the Arc network as an enterprise-grade blockchain intended as an economic operating system for internet-scale commerce, and said Agent Stack will act as an execution layer that can migrate onto Arc as the network develops.

Jeremy Allaire, Circle’s CEO, described the historical limits of financial infrastructure for software and said the Agent Stack is the company’s first full suite built with AI agents as primary customers: “Financial infrastructure has historically been built for people, with manual onboarding, approvals, and payment flows that were never designed for software acting on its own.”