{"protocol":"x402","x402Version":2,"guidanceVersion":"2026-10-02.v2","purpose":"Machine-readable payment instructions for agents calling Rafid x402 capability endpoints.","flow":["POST the capability endpoint without payment","parse PAYMENT-REQUIRED","create the exact payment","retry the same method, URL, and JSON body with PAYMENT-SIGNATURE"],"headers":{"challenge":"PAYMENT-REQUIRED","payment":"PAYMENT-SIGNATURE","legacyPayment":"X-PAYMENT","settlement":["X-PAYMENT-RESPONSE","PAYMENT-RESPONSE"]},"clients":{"javascript":{"packages":["@x402/fetch","@x402/evm"],"install":"npm install @x402/fetch @x402/evm"},"generic":"Any client that implements x402 v2 exact payments can parse the challenge and retry the unchanged request."},"network":"eip155:8453","asset":"USDC","paymentRequired":true,"noPayment":"A 402 challenge never charges the caller. Do not retry unpaid requests repeatedly; use an x402-compatible client or SDK.","endpointPattern":"/api/v1/x402/<capability-path>"}