Unverified50% confidenceFactExact time
In x402 v2, the PAYMENT-REQUIRED header of the 402 response contains base64-encoded payment terms; in x402 v1, the payment requirements are provided as JSON in the response body for compatibility with older clients.
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Long-term
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10/19/2026
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Related Claims
UnverifiedThe x402 protocol reuses HTTP's 402 Payment Required status code, letting the server declare in its response the amount, asset, and settlement chain required to pay for the call, on which basis the client completes signing and retries.80% similarUnverifiedThe custom HTTP headers PAYMENT-REQUIRED and PAYMENT-SIGNATURE are the data carriers of the x402 protocol; an ordinary browser or unadapted client will only see the 402 and JSON response body and will not mistakenly trigger a payment.74% similarUnverifiedThe name x402 is derived from HTTP status code 402 (Payment Required), which was defined in the HTTP/1.1 specification but has long been reserved and unused.71% similarUnverifiedPublic-network MCP tools commonly use the JWT (JSON Web Token) authentication standard (RFC 7519), where a JWT token consists of three parts: Header, Payload, and Signature.61% similarUnverified断点续传依赖于 HTTP/1.1 协议中的 Range 请求头机制（RFC 7233），服务器返回 206 Partial Content 状态码61% similar
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