Data notary API your feed, witnessed.
Your customers shouldn't have to trust your feed — they should be able to verify it. One call sends your data (or only its hash, in private mode) and returns a timestamped, Ed25519-signed witness record from a neutral third party: proof these exact bytes existed at this moment.
The call
Free key to start. Anchor any record on Bitcoin via POST /v1/anchor for proof-of-when that doesn't depend on us.
# 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 hash
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
Every data provider faces the same question: why should anyone believe your numbers were what you say they were, when it matters — in a dispute, an audit, a claim? Building a signing stack is real cryptographic work. This is that stack, as one API call, from a neutral party with a published key and a public verification spec.
Use it for
- Sensor and IoT feeds that end up as evidence
- Research data with reproducibility requirements
- Price/market feeds whose history gets disputed
- Any provider who wants 'verifiable' on the label without building PKI
FAQ
What does a notarization attest?
That Dynamic Feed witnessed these exact bytes (or this hash) at witnessed_at — not that the content is true. It makes after-the-fact alteration provable.
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 you.
Is there a public record?
Yes — every notarization lands in an append-only, hash-chained transparency log (GET /v1/notary/log, payload hashes only). The chain head is anchored to Bitcoin daily, so rewriting any entry is detectable by anyone, forever.
Can I sign with my own key?
Yes — BYO-key mode: send provider_pubkey + provider_sig (Ed25519 over your payload hash) and the record reads 'provider signed, Dynamic Feed witnessed' — two-party proof.
How does anyone verify it?
The Ed25519 signature checks against /.well-known/keys with the public recipe at /standard — no account needed, forever.
Can I prove WHEN independently of you?
Yes — POST /v1/anchor timestamps the record's hash on Bitcoin via OpenTimestamps, free.
What does it cost?
Notarizations work on any plan's call quota today. The dedicated Notary plan is US$49/month for 10,000 notarizations during beta — including BYO-key, the public transparency log and up to 3 continuous feeds. Self-serve checkout at dynamicfeed.ai/notary; per-receipt enterprise pricing for insurers and platforms.
Can my feed be notarized automatically?
Yes — register it once (POST /v1/notary/feeds) and every change is fetched and notarized into the public log on your interval. A standing, tamper-evident history of what you published.