Coinbase has reintroduced the HTTP 402 status code, originally intended for 'Payment Required,' to facilitate a new micro-payment protocol for AI-driven economies. The x402 protocol integrates payments into HTTP requests, enabling efficient, low-cost machine-to-machine transactions. This innovation has garnered interest from major entities such as PayPal, Google, and the Federal Reserve Bank of Atlanta, which view x402 as a potential standard for machine payments. Leveraging its Base network and USDC, Coinbase aims to provide scalable infrastructure for micro-payments, particularly for AI agents handling tasks like API calls and model inference fees. The x402 protocol is distinct from Coinbase's Base Commercial Protocol, which is designed for more complex e-commerce applications. Early adopters of x402 include AI platforms Questflow and GoKiteAI, with support from Cloudflare, AWS, and Anthropic.