{"uid":"cap_IUvkQ1mV_GD33eAZHrOf6","slug":"x402-offer-replay-hygiene-auditor-d77654e7","name":"x402 Offer Replay Hygiene Auditor","description":"Choose Blockchain Money Map for human-readable public blockchain reports, x402-paid agent API services, agent workflow packs, custom agent builds, or an Agent Radar pilot preview.","url":"https://api.blockchainmoneymap.com/api/x402/x402-offer-replay-hygiene-auditor?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"mode":{"enum":["audit"]},"facts":{"type":"object","required":["pay_to","amount","currency","network","valid_from","valid_until","nonce_present","signature_present","scheme"],"properties":{"amount":{"type":"number"},"pay_to":{"type":"string","maxLength":500},"scheme":{"type":"string","maxLength":500},"network":{"type":"string","maxLength":500},"currency":{"type":"string","maxLength":500},"valid_from":{"type":"string","maxLength":500},"valid_until":{"type":"string","maxLength":500},"nonce_present":{"type":"boolean"},"resource_hash":{"type":"string","pattern":"^sha256:[a-fA-F0-9]{64}$"},"resource_label":{"type":"string","maxLength":500},"signature_present":{"type":"boolean"}},"additionalProperties":false},"policy":{"type":"object","additionalProperties":true},"reference_facts":{"type":"object","required":["pay_to","amount","currency","network","valid_from","valid_until","nonce_present","signature_present","scheme"],"properties":{"amount":{"type":"number"},"pay_to":{"type":"string","maxLength":500},"scheme":{"type":"string","maxLength":500},"network":{"type":"string","maxLength":500},"currency":{"type":"string","maxLength":500},"valid_from":{"type":"string","maxLength":500},"valid_until":{"type":"string","maxLength":500},"nonce_present":{"type":"boolean"},"resource_hash":{"type":"string","pattern":"^sha256:[a-fA-F0-9]{64}$"},"resource_label":{"type":"string","maxLength":500},"signature_present":{"type":"boolean"}},"additionalProperties":false}}},"responseSchema":{"type":"json"},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_lXjkUxYAxXpluVAYTMZPv","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Audits an x402 payment offer for replay hygiene by comparing its facts against a reference offer and validating fields like nonce, signature, validity window, and payment details.","exampleAgentPrompt":"Audit this x402 offer for replay hygiene: pay_to is 0xABC123, amount 0.01, currency USDC, network base-mainnet, valid_from 2024-01-01T00:00:00Z, valid_until 2024-01-01T01:00:00Z, nonce present, signature present, scheme x402 — compare it against the reference offer with the same fields but valid_until 2024-01-01T00:30:00Z and tell me if there are any replay or hygiene issues.","exampleUseCases":[{"title":"Detect replayed x402 micropayment offer","prompt":"I received what looks like a duplicate x402 payment offer — pay_to 0xDEF456, amount 0.01 USDC on base-mainnet, valid_from 2024-06-01T10:00:00Z to valid_until 2024-06-01T10:05:00Z, nonce present, signature present, scheme x402. Compare it against the original offer I saw yesterday with the same pay_to and amount but a different valid_until, and tell me if this is a replay attack."},{"title":"Validate nonce and signature hygiene before payment","prompt":"Before my agent pays this x402 offer, audit it for replay hygiene: pay_to 0x111AAA, amount 0.05, currency USDC, network ethereum, valid_from 2024-07-15T08:00:00Z, valid_until 2024-07-15T09:00:00Z, nonce is present, signature is present, scheme x402 — no reference offer needed, just check if the fields look clean."},{"title":"Cross-check two x402 offers for duplication","prompt":"Can you compare these two x402 offers to see if one is a replay of the other? Current offer: pay_to 0xCAFEBABE, amount 1.00, currency USDC, network base-mainnet, valid_from 2024-08-01T00:00:00Z, valid_until 2024-08-01T01:00:00Z, nonce present, signature present, scheme x402. Reference offer: same pay_to and amount, but valid_until is 2024-08-01T00:45:00Z and the resource hash is sha256:a3f1c2d4e5b6789012345678901234567890123456789012345678901234abcd."}],"resultDescription":"A JSON object containing the audit outcome, including whether the x402 offer passes replay hygiene checks, any detected field mismatches between the offer and reference, flags for missing or invalid nonce/signature/validity-window fields, and an overall hygiene assessment indicating whether the offer is safe to process or potentially replayed.","failureModes":["Missing required fields in facts object returns a validation error","Invalid resource_hash format (not matching sha256:[64 hex chars]) causes schema rejection","Mismatched network or currency between facts and reference_facts may flag false positives if intentional","Mode must be set to 'audit' or the request will be rejected","Expired or future-dated valid_from/valid_until values may cause hygiene failures","Payment via x402 fails if USDC balance is insufficient"],"whenToPreferThis":"Use this endpoint when your agent needs to programmatically verify that an x402 payment offer has not been replayed or tampered with before processing payment — especially when you have a reference offer to compare against. Prefer this over manual field comparison when operating in automated agent pipelines where replay attacks on micropayment offers are a security concern.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T04:49:50.503Z","isFirstParty":false,"canonicalSlug":"x402-offer-replay-hygiene-auditor-d77654e7"}