Coinbase’s x402 protocol drives $42 million in stablecoin payments, 97% agent adoption

Coinbase has introduced x402, an open payment standard leveraging the long-dormant HTTP 402 “Payment Required” code, to enable machine-to-machine and AI agent payments using stablecoins across the web. Launched in May 2025, x402 allows APIs, apps, and autonomous software to pay directly for digital services without traditional accounts, API keys, or intermediaries. Payments are mainly made in USDC, the dollar-pegged stablecoin from Circle, settled on Coinbase’s layer-2 Base network with facilitators handling blockchain interactions. The protocol supports multiple networks, including Solana , Polygon , and Arbitrum, as well as traditional payment cards.