The July 31 API adds no-login discovery to Circle's May 11 Agent Stack of USDC wallets, marketplace and nanopayments, while Circle said an ARC token presale raised $222 million for its planned Arc Layer-1.
Circle's AI-agent payments push now spans its May 11 Agent Stack launch and a July 31 expansion. The initial release introduced Circle CLI, Agent Wallets with programmable spending controls, an Agent Marketplace for service discovery, and Nanopayments through Circle Gateway for near-instant, gas-free transfers as small as $0.000001 in USDC. On July 31, Circle added a public Discovery API that lets autonomous software browse and filter pre-screened USDC-accepting services without user authentication, using 14 query parameters across Arbitrum, Base and Ethereum. Circle said marketplace participants undergo sanctions-compliance and operational-health reviews. In the May 11 announcement, Circle also said its ARC token presale raised $222 million at a $3 billion valuation for Arc, a proposed stablecoin-native Layer-1 where fees would be paid in USDC.