x402, an open-source payment protocol incubated by Coinbase and designed specifically for artificial intelligence (AI) agents, is releasing a major upgrade approximately six months after its initial launch. x402 V2 essentially transforms the previously simple, one-off payment system into a mature, internet-facing unified payment layer. Version V2 includes a series of backend improvements designed to make it easier to create customizable payment processes, better wallet and identity features, and support for "traditional payment systems." The biggest upgrade in V2 is the unification of x402's payment interface. x402 V2 standardizes the way networks and assets are identified in the protocol, "creating a single payment format that works across different blockchains and traditional payment systems." This means that x402 will "support multiple chains by default," enabling support for native tokens of other blockchains such as Base or Solana without requiring custom logic. Furthermore, the system is compatible with "traditional payment systems" such as ACH and bank card networks. The updated system also introduces dynamic "payTo" routing, supporting payment processes such as usage-based billing, subscriptions, prepaid payments, and multi-step transactions. Developers can also inject "lifecycle hooks" for conditional tools or metric monitoring, and create more customized payment walls. (The Block)