Code Awakening After Thirty Years x402 Protocol AI Autonomous Payment Revolution

Rebirth of HTTP 402 Status Code

The HTTP 402 (Payment Required) status code defined in 1997 only saw practical application in recent years. In 2025, Coinbase, in collaboration with giants like Cloudflare, Google, and Visa, launched the x402 protocol to add automatic payment functionality to web services, enabling AI to complete payments and receive service responses without human intervention.

The technical architecture of the x402 protocol

The protocol is built on the existing HTTP standard without the need to change the underlying network structure. It relies on a payment coordination layer responsible for transaction authorization and on-chain settlement, and uses a multi-chain compatible blockchain abstraction layer to ensure cross-chain payment scalability, allowing websites and AI agents to easily integrate this payment mechanism for instant and secure automated transactions.

New Model of Micro-Payments

Traditional payment methods have high fees and slow settlement, often accompanied by refund risks, while the x402 protocol, relying on the Base blockchain, has a transaction cost as low as 0.0001 USD and can complete settlements in about 2 seconds, featuring irreversibility and fraud prevention characteristics, making it ideal for small transactions and instant data exchange between AI.

Diverse practical application scenarios

x402 enables AI to possess real payment capabilities, allowing it to automatically purchase paid news, pay API usage fees, or transact instantly with other intelligent agents. This changes payments from being an additional module to becoming a fundamental function of network communication, driving the intelligent development of the entire ecosystem.

Summary

The emergence of x402 is not just a technological innovation, but a historic correction. Thirty years ago, the 402 status code was not activated; thirty years later, it has become the beginning of the integration of AI, Web3, and online payments. In the future digital ecosystem, every AI, every API, and even every user will be able to freely create, exchange, and provide value.