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SHA-256 Hash & HMAC Timestamp Audit Seal
x402
SHA-256 Hash & HMAC Timestamp Audit Seal is a paid API for AI agents from api.ibancheck.co.uk, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-13).
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.
Price / call$0.003
Success—
StatusUnknown
How this service works
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).
Output
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.
Example use cases
AI agent action audit trail
“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"}”
Contract document integrity proof
“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...”
Compliance log sealing for fintech
“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"}”
Technical details
Endpoint
POSThttps://api.ibancheck.co.uk/api/hash-timestamp?utm_source=zero.xyzWhen to prefer
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.
Side effects
- 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
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| payload | object | |
| fileBase64 | string |
Tags
x402
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