X402

X402 introduces a standardized framework for blockchain-native agent payments, enabling autonomous software agents to transact, coordinate, and compensate one another without relying on traditional financial rails. By embedding payment logic directly into agent interactions, X402 defines a permissionless, programmable payment layer where identity, execution, and settlement are unified on-chain. This proposal outlines how X402 can serve as a foundational primitive for agent economies—supporting microtransactions, streaming payments, and conditional execution across decentralized networks. The result is a system where agents are not only actors, but also economic participants capable of trust-minimized value exchange in real time.

As autonomous agents become more capable—driven by advances in AI, decentralized infrastructure, and composable smart contracts—their ability to operate independently is outpacing the financial systems available to them. Today, agents rely on human-controlled wallets, API keys tied to centralized billing systems, or fragmented payment flows that introduce friction, latency, and counterparty risk.