Data notarization API: proof in one POST.
Send bytes or only their digest and receive a signed witness receipt plus a hash-chained log entry whose commitments can be checked. Notary plans are in early access, with a free-key quota for evaluation.
The call
Free key to start; self-serve checkout at /notary when you're ready. Every record is Ed25519-signed and lands in the public transparency log above.
# notarize a reading from YOUR feed (free key: POST /signup)
curl -X POST https://dynamicfeed.ai/v1/notarize -H "X-API-Key: $KEY" \
-H "content-type: application/json" \
-d '{"payload": {"sensor": "rain_gauge_7", "mm": 18.4}, "subject": "Acme Sensors"}'
# private mode — we never see your data, only its sha256
curl -X POST https://dynamicfeed.ai/v1/notarize -H "X-API-Key: $KEY" \
-d '{"payload_sha256": "", "subject": "Acme Sensors"}' Sample response
{ "schema": "notary/v1", "issuer": "dynamicfeed.ai",
"witnessed_at": "2026-06-10T09:27:32+00:00", "mode": "payload",
"payload_sha256": "e9e325a2…", "subject": "Acme Sensors Pty Ltd",
"signature": { "alg": "Ed25519", "key_id": "df-ed25519-…" } }Why live data
When a customer, auditor or insurer asks what your feed reported, an internally controlled database may not be enough. A notarization is a signed witness receipt for exact bytes or their digest, carrying witnessed_at and linked into a hash chain. Open verifiers let customers check signature integrity and record commitments without an account. The signature establishes integrity and attribution, not objective truth or independent time. An RFC 3161 artifact can be requested separately and must be fully validated before relying on time evidence.
Use it for
- Sensor and IoT feeds that end up as evidence in disputes and claims
- Price and market feeds whose history gets argued about
- Research datasets with reproducibility requirements
- AI systems recording exactly what data they acted on (see the EU AI Act page)
FAQ
What does it cost?
Notarizations work on any plan's normal call quota today, so you can try it on a free key first. A dedicated Notary plan is in early access — request access at /request-access and tell us your volume.
What does a notarization attest?
That Dynamic Feed witnessed these exact bytes (or this hash) at witnessed_at — not that the content is true. That honest line is printed inside every record we sign.
Do you see my data?
Only in payload mode. In hash-only mode you send a sha256 and we witness the hash — your bytes never leave your infrastructure.
How do my customers verify a record?
Check the Ed25519 signature against /.well-known/keys using the public recipe at /standard, then recompute the record commitment and inspect its chain relationships. If an RFC 3161 artifact is present, validate its token, digest binding and certificate path separately.
Can it run automatically?
Yes — register a feed URL and an interval (POST /v1/notary/feeds) and every change is fetched and notarized into the public log: a standing, tamper-evident history of what you published.