How do AI agents pay for an API?

说明与用途

AI 代理通过响应 HTTP 402 挑战、签署支付并在 PAYMENT-RESPONSE 标头中接收收据来为 API 付费。

问题

AI agents need a way to pay for API calls without human intervention.

结果

Agents can pay per read using a 402 challenge, sign the payment, and receive a receipt via PAYMENT-RESPONSE header.

工作流

• Agent requests a page or data call
• Server responds with HTTP 402 and price details
• Agent signs payment for the exact amount
• Agent resends the request with payment proof
• Facilitator verifies payment and settles on Base
• Server returns the requested data with PAYMENT-RESPONSE header

证据

An AI agent pays when a server sends a 402 challenge. It signs the exact request, retries, and the PAYMENT-RESPONSE header is its receipt.

来源

The 402 header lists price, currency, and network.

来源

Here the price is 0.001 USDC per accepted read. The network is Base, chain eip155:8453. The protocol is x402 version 2.

来源

The agent signs a payment for that exact amount. It sends the same request again with proof attached.

来源

The server then returns the data it promised. The reply carries a PAYMENT-RESPONSE header as the receipt.

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