{"uid":"cap_Z8zjCcVLEY6HtTVY5LyfD","slug":"x402-nonce-book-diagnostic-endpoint-b9be1e05","name":"x402 Nonce Book Diagnostic Endpoint","description":"Paid x402 diagnostics. Unpaid paid-SKU requests return HTTP 402 with eip3009 extras. Facilitator: OpenX402 only.","url":"https://openclawproductions.com/api/v1/noncebook?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"properties":{"type":"string"}}},"responseSchema":{"type":"json","example":{"sku":"noncebook","note":"Example paid JSON shape. Not a live settle.","price":"$0.16","title":"Nonce Book"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.16","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.16/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.16","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.16","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_pa4d66utmu4yRymbNHfAJ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.16","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns a paid JSON diagnostic payload (the 'Nonce Book' SKU) to verify x402 micropayment flow and EIP-3009 authorization on the OpenX402 facilitator network.","exampleAgentPrompt":"Can you hit the x402 Nonce Book diagnostic endpoint to verify my OpenX402 payment flow is working — it should cost $0.16 USDC and come back with a paid JSON payload confirming the noncebook SKU settled correctly?","exampleUseCases":[{"title":"Verify x402 agent payment integration","prompt":"Run the Nonce Book diagnostic against the OpenX402 facilitator and confirm that my agent's EIP-3009 payment of $0.16 USDC goes through and returns the expected paid JSON payload."},{"title":"Debug HTTP 402 response format","prompt":"Hit the noncebook endpoint without paying first so I can inspect the raw HTTP 402 response and EIP-3009 extras that come back — I need to make sure my client is parsing the payment challenge correctly."},{"title":"Smoke-test paid SKU before production deploy","prompt":"Make a paid call to the Nonce Book SKU on openclawproductions using OpenX402 as the facilitator, and show me the full JSON response so I can confirm the paid flow works end-to-end before I go live."}],"resultDescription":"A JSON object containing the SKU identifier ('noncebook'), a diagnostic note clarifying this is an example paid response shape, the price ($0.16), and the title ('Nonce Book'). Unpaid requests receive HTTP 402 with EIP-3009 payment challenge extras instead.","failureModes":["HTTP 402 returned when no valid x402 payment header is included — response contains EIP-3009 extras describing required payment","Payment facilitator mismatch — only OpenX402 is accepted; other facilitators will be rejected","Insufficient USDC balance causes payment failure before request is fulfilled","Malformed EIP-3009 authorization signature results in payment rejection","Network or RPC errors on the facilitator side may cause intermittent failures"],"whenToPreferThis":"Choose this endpoint when you need to test or verify that an x402 micropayment pipeline — specifically using the OpenX402 facilitator and EIP-3009 USDC authorization — is functioning correctly end-to-end. It is purpose-built for diagnostics, not production data retrieval. Prefer it over generic HTTP checkers when you specifically need to validate the paid-SKU 402 challenge/response cycle and confirm that $0.16 USDC micropayments settle correctly.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T18:42:34.595Z","isFirstParty":false,"canonicalSlug":"x402-nonce-book-diagnostic-endpoint-b9be1e05"}