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Hermes Notar
x402
Hermes Notar is a paid API for AI agents from notar.185-190-142-134.sslip.io, paid per call via x402, $0.02/call, status unknown (last checked 2026-11-04).
Timestamps a SHA-256 digest with a Nostr-signed receipt and a Bitcoin-anchored OpenTimestamps proof for verifiable provenance
Price / call$0.02
Success—
StatusUnknown
How this service works
Send a SHA-256 digest of your output. Get an instant Nostr-signed receipt and a Bitcoin-anchored OpenTimestamps proof that anyone can verify without trusting us. Use it as proof of delivery, proof of authorship, or audit trail (e.g. EU AI Act logging).
Output
Returns a JSON object containing a token string (the signed notarization receipt), a transaction identifier (Bitcoin or Nostr anchor reference), and a rest field indicating remaining quota. The token and transaction together constitute verifiable, trustless proof that the submitted digest existed at the time of the call, anchored to the Bitcoin blockchain via OpenTimestamps and signed via Nostr.
Example use cases
EU AI Act compliance audit trail
“I need to log proof that our AI model produced this specific output — can you hash it and get a Bitcoin-anchored OpenTimestamps receipt from Hermes Notar so we have an immutable audit trail?”
Proof of authorship for creative work
“I've got the SHA-256 digest of my manuscript draft — timestamp it on Bitcoin and give me a signed receipt so I can prove I authored it before today's date.”
Proof of delivery for a legal document
“We just sent a contract to the client — submit its SHA-256 hash to Notar and get me a timestamped, Nostr-signed proof of delivery I can attach to the case file.”
Technical details
Endpoint
GEThttps://notar.185-190-142-134.sslip.io/x402/token?utm_source=zero.xyzWhen to prefer
Choose Hermes Notar when you need trustless, publicly verifiable proof of existence for a document or output hash — especially when you cannot rely on a centralized notary. It is ideal for EU AI Act compliance logging, proof-of-authorship disputes, and audit trails where the verifier must be able to confirm the proof independently using open-source tools (OpenTimestamps CLI or a Nostr client) without trusting the service operator. Prefer this over simple database logging when tamper-evidence and third-party verifiability are required.
Side effects
- Invalid or malformed SHA-256 digest returns an error response
- Insufficient USDC balance or failed x402 payment results in 402 Payment Required
- Bitcoin network congestion may delay final OpenTimestamps confirmation (receipt is instant, block confirmation is deferred)
- Rate limiting if quota (rest field) is exhausted
- Network timeout if the Nostr relay or OTS calendar is temporarily unavailable
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| properties | string |
Output
Schema · Response
{
"type": "json",
"example": {
"rest": 100,
"token": "abc...",
"transaction": "0x..."
}
}Tags
x402
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