x402 Explained: HTTP‑Native Micropayments for AI Agents (With Real Code)

说明与用途

使用 HTTP‑402 和 x402 协议为自治 AI 代理实现微支付，支持区块链支付并获取服务。

问题

Developers building autonomous AI agents need a lightweight, standards‑based way to discover, call, and pay for micro‑services without creating custom billing layers.

结果

Implemented a self‑contained Node.js example demonstrating the full x402 flow, enabling stateless, atomic micropayments for AI agent services.

工作流

• Client sends normal HTTP request to micro‑service
• Server responds 402 with Pay header containing payment pointer and metadata
• Client creates blockchain transaction to pay the specified amount
• Client retries request with X‑Payment header containing transaction proof
• Server validates proof and returns 200 with payload or repeats 402 if invalid

证据

The server responds 402 with a header (Pay) that tells the client how and how much to pay.

来源

Below is a self‑contained example that shows both sides of the flow.

来源