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Ysaere Notary — Hash Receipt
x402
Ysaere Notary — Hash Receipt is a paid API for AI agents from api.ysaere.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-13).
Notarizes a document or data payload by creating a cryptographically signed hash receipt for ~$0.02 USDC, returning a signature and a public verification URL.
Price / call$0.02
Success—
StatusUnknown
How this service works
Ysaere Notary — pay ~$0.02 USDC → signed hash_only receipt + verify_url; free GET resolve/proof (integrity, not factual truth).
Output
Returns a JSON object containing: a signed SHA-512 content hash (v2:sha512:…), a cryptographic signature, a public verify_url where anyone can confirm the receipt, the payment rail used (x402), and the on-chain transaction hash. The receipt proves integrity (that the content was unchanged) but not factual truth of the content itself.
Example use cases
Proof of existence for a contract
“I just finalized a vendor agreement and need a tamper-proof receipt proving it existed as of today — can you notarize the document content and give me a verify URL I can share with the other party?”
Dataset integrity stamp for audit
“Before I hand off this dataset to the regulator, notarize its hash so we have a signed receipt showing the data was unchanged at submission time.”
Timestamping creative work
“I've written a new design spec and want to prove I authored it today — can you hash and sign it with Ysaere so I get a verifiable receipt I can save?”
Technical details
Endpoint
POSThttps://api.ysaere.com/v1/notary/receiptsWhen to prefer
Choose this endpoint when you need a lightweight, low-cost (~$0.02) cryptographic proof-of-existence for any document, file, or data payload. It is ideal when you want an externally verifiable, signed receipt without storing the original content — only its hash is retained. Prefer it over full KYB or entity classification endpoints when your goal is integrity attestation rather than identity verification. Best for audit trails, timestamping creative or legal work, or producing receipts that third parties can independently verify via the returned verify_url.
Side effects
- Insufficient USDC balance or payment failure — x402 payment not completed, no receipt created
- Malformed or missing content body — 400 error, hash cannot be computed
- Network timeout during signing — partial failure, receipt may not be issued
- Invalid content encoding — the endpoint may reject non-UTF-8 or oversized payloads
- Duplicate notarization of identical content — returns a new receipt each time (not idempotent)
Output
Schema · Response
{
"type": "json",
"example": {
"data": {
"mode": "hash_only",
"verified": true,
"signature": "…",
"verify_url": "https://api.ysaere.com/v1/notary/receipts/…",
"content_hash": "v2:sha512:…"
},
"usage": {
"payment_rail": "x402",
"x402_tx_hash": "0x…",
"credits_consumed": 0
},
"provenance": {
"kind": "external_attestation",
"mode": "hash_only",
"signature": "…",
"verify_url": "https://api.ysaere.com/v1/notary/receipts/…"
}
}
}Tags
x402
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