Circle’s x402 Facilitator Service goes live on Arc, supports Base and Polygon PoS

Circle just made it a lot easier for API providers, data services, and AI agents to get paid in USDC. The company’s x402 Facilitator Service is now live, processing payments across three networks: Circle’s own Arc blockchain, Coinbase’s Base, and Polygon PoS. The service launched on September 16, 2026, the same day Circle’s Arc mainnet went public. What the x402 Facilitator Service actually does The HTTP 402 status code has existed since the early days of the web. It was originally reserved for “Payment Required” but never saw real adoption because the internet didn’t have native money rails. The x402 protocol changes that by embedding USDC payments directly into HTTP request-response flows. Circle’s Facilitator Service handles the messy middle part. Sellers don’t need to spin up their own relayer infrastructure, fund gas wallets, or run sanctions screenings. Circle verifies the buyer’s signed EIP-3009 authorization and settles the transaction on-chain. All the seller needs is a Circle API key to get started, with a keyless trial option available for those who want to test the waters. The service uses what Circle calls the “exact” scheme for processing payments across the three sup...