{"uid":"cap_8TgM788r_MfrzH5gHE4yv","slug":"sha-256-hash-hmac-timestamp-audit-seal-2fd1f653","name":"SHA-256 Hash & HMAC Timestamp Audit Seal","description":"Enterprise microservice and autonomous AI agent hub: ISO 13616 IBAN (#6), Romanian CUI Modulo-11 & EU VIES (#7), UBL 2.1 e-Factura XML (#4), and RFC 9562 UUIDv7 Idempotency (#18).","url":"https://api.ibancheck.co.uk/api/hash-timestamp?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"payload":{"type":"object"},"fileBase64":{"type":"string"}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm__oXmbzCba69DkvOz44xWt","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Generates a cryptographic SHA-256 hash and HMAC timestamp audit seal for a JSON payload or base64-encoded file, creating a tamper-evident proof of data at a specific moment in time.","exampleAgentPrompt":"Create a cryptographic SHA-256 hash and HMAC timestamp audit seal for this JSON payload — I need a tamper-evident record proving this data existed unchanged right now: {\"orderId\":\"ORD-9921\",\"amount\":450.00,\"currency\":\"EUR\",\"action\":\"approved\"}","exampleUseCases":[{"title":"AI agent action audit trail","prompt":"Generate a cryptographic SHA-256 hash and HMAC timestamp seal for this agent action record so I have an immutable audit log entry: {\"agentId\":\"agent-42\",\"action\":\"transfer_approved\",\"amount\":1200,\"timestamp\":\"2024-06-15T14:32:00Z\"}"},{"title":"Contract document integrity proof","prompt":"Hash and timestamp-seal this base64-encoded PDF contract so I can prove it hasn't been altered since today — here's the file in base64: JVBERi0xLjQKJcfsj6IKNSAwIG9iago..."},{"title":"Compliance log sealing for fintech","prompt":"I need to create a tamper-evident audit seal for this compliance event payload before storing it in our records: {\"event\":\"KYC_passed\",\"userId\":\"U-88812\",\"verifiedAt\":\"2024-06-15\",\"provider\":\"ibancheck\"}"}],"resultDescription":"Returns a SHA-256 hash of the input payload or file, an HMAC-based timestamp seal binding the hash to the current moment, and metadata such as the timestamp used — forming a verifiable, tamper-evident audit record proving the data's content and existence at that point in time.","failureModes":["Empty or missing payload and fileBase64 fields returns a validation error","Malformed base64 encoding for fileBase64 causes decoding failure","Oversized payloads may be rejected or time out","Network errors or service unavailability return HTTP 5xx","Invalid JSON structure in payload object results in parse error"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, pay-per-call cryptographic audit seal without standing up your own hashing infrastructure — especially useful for AI agents that need to produce tamper-evident logs of their actions, for compliance workflows requiring proof-of-existence, or when you need both a SHA-256 content hash and an HMAC timestamp in a single call. Pairs naturally with the sibling hash-verify endpoint for later tamper detection.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-13T12:43:37.253Z","isFirstParty":false,"canonicalSlug":"sha-256-hash-hmac-timestamp-audit-seal-2fd1f653"}