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Genexxis Notary Stamp
x402
Genexxis Notary Stamp is a paid API for AI agents from notary.genexxis.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-29).
Timestamps a SHA-256 hash and returns a cryptographically signed receipt proving the hash existed at a specific moment in time.
Price / call$0.002
Success—
StatusUnknown
How this service works
Timestamp a SHA-256 hash: returns a stored, server-signed receipt (id, hash, label, timestamp, signer, message, signature, verify URL) proving the hash was presented at that time.
Output
A JSON receipt containing: a unique record ID (UUID), the submitted hash, the optional label, the server's signer Ethereum address, an ISO 8601 timestamp of when the hash was presented, a structured signed message string, a 65-byte cryptographic signature over that message, and a verifyUrl pointing to the endpoint where the receipt can be independently verified.
Example use cases
Pre-deadline contract submission proof
“I need to prove this contract existed before the submission deadline — can you stamp the SHA-256 hash a3f8c2d19b0e47f65c1d8a290bcf3e7a4521b0d6e8f9c3a71d2b4e5f08c6a19d with the label 'vendor-contract-Q4-2025' and give me the signed receipt?”
Intellectual property creation timestamp
“I just finished writing my white paper and want proof of when it was created — please timestamp the SHA-256 hash 7d4e2a1f9b3c8e6d0f5a2c7b4e1d8f3a6c9b0e5d2f7a4c1b8e3d6a9f0c5b2e8 with the label 'whitepaper-original-draft'.”
Software release integrity certification
“Before I publish this software release, stamp the hash 2b9f4e1d7a3c6b8e0f5d2a9c4b7e3f1d6a8c0b5e2f4a7c9b1e3d8f6a0c2b5e9 with the label 'app-v2.3.1-release' so users can verify it hasn't been tampered with.”
Technical details
Endpoint
POSThttps://notary.genexxis.com/stamp?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a lightweight, cryptographically signed proof-of-existence for a document or file hash without requiring a full blockchain transaction. It is ideal for compliance workflows, legal timestamping, intellectual property protection, and audit trails where a server-signed receipt is sufficient. Prefer this over blockchain anchoring when cost, latency, or simplicity are priorities, and the trust anchor of a known server key is acceptable.
Side effects
- Invalid hash format (not 64 hex chars) returns a 400 error
- Hash with invalid characters or wrong length rejected
- Label exceeding 120 characters or containing pipe character rejected
- Payment failure or insufficient USDC balance returns 402
- Server signing key unavailable returns 500
- Duplicate hash submission creates a new independent receipt (not idempotent)
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| hash | string | SHA-256 digest of your document, 64 hex chars, optional 0x prefix |
| label | string | Optional label, max 120 chars, no | character |
Output
Schema · Response
{
"type": "json",
"example": {
"id": "3f2b8c1e-5d4a-4f7b-9a62-1c0e8d7f6a55",
"hash": "0x1a19868d3b6b3f57f523b3202b9ae40155dc1491b3727c608f573acc615d9a0c",
"label": "contract-v1",
"signer": "0x02A5A59fdC30Ec50c091F7EE1486D08B49F56940",
"message": "genexxis-notary:v1|stamp|0x1a19868d3b6b3f57f523b3202b9ae40155dc1491b3727c608f573acc615d9a0c|2026-10-24T20:55:00.123Z|contract-v1",
"signature": "0x...65-byte signature",
"timestamp": "2026-10-24T20:55:00.123Z",
"verifyUrl": "https://notary.genexxis.com/verify"
}
}Tags
x402
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