Coinbase’s x402 started as a clever revival of the HTTP 402 “Payment Required” code, enabling native, pay-per-request crypto payments directly over the web, especially for APIs and machine-to-machine use cases.
Over time it evolved into an agent-friendly payment layer, seeing real adoption across Base and other chains as AI agents began transacting autonomously.
The latest updates push x402 further toward a standard, with multi-chain support, better routing, and growing ecosystem backing, positioning it as core infrastructure for AI-native and internet-native payments.