Circle has launched its x402 Facilitator Service, enabling API providers, data services, and AI agents to receive USDC payments. The service integrates directly into HTTP request-response flows, allowing sellers to bypass the need for managing relayers, gas wallets, or sanctions screenings.
The platform supports payments across three networks: the newly public Arc mainnet, Base, and Polygon PoS. Circle verifies EIP-3009 authorizations and handles on-chain settlement, requiring only a Circle API key from the seller.
Arc is an EVM-compatible Layer 1 blockchain where USDC functions as the gas token. Its founding validators include BlackRock, DTCC, and Visa. At the time of the public launch on September 16, 2026, more than 100 partners and applications were operational on the network.
During its testnet phase, Arc processed between 500 million and 700 million transactions. While Circle has minted a total supply of 10 billion ARC tokens, the company has not announced plans for a public token launch.
The x402 service builds on the Agent Stack released in May 2026, which supports autonomous transactions for AI agents. Data indicates that 98.8% of the volume in agent-to-agent x402 payments is conducted in USDC.
