The earliest provable copy wins.
Prove a document, dataset or image existed in this exact form on this date, without showing it to anyone. A reporter's notes, a leaked spreadsheet, a photo before it was contested, a dataset before a source recanted: the earliest provable copy wins arguments that memories lose. Hash the file in your browser so nothing leaves your machine, notarize the hash with a neutral witness, and hold an Ed25519-signed, RFC 3161 timestampable fixed point that any party can re-verify years later with the open verifiers. Hash only, zero content shared.
Fingerprint the source, privately.
Pick a file, or paste text, and your browser computes its SHA-256 fingerprint locally with the Web Crypto API. This is the exact hash you would notarize. The content is hashed in your browser and never uploaded. Nothing is stored about you.
intake record (JSON)
curl -X POST https://dynamicfeed.ai/v1/notarize -H "content-type: application/json" -H "X-API-Key: YOUR_FREE_KEY" -d '{"hash":"sha256:<your hash>","ref":"source-<slug>-first-copy"}'
The returned record is Ed25519-signed with its key_id and is RFC 3161 timestampable against an accredited authority. Re-verify it any time against /.well-known/keys or with the MIT-licensed verifiers on PyPI, npm and crates.io (see /verify and /standards). A free key is self-serve at POST /signup, details in the docs.
What the world looked like that day.
A source record is stronger when the moment around it is stamped too. This pulls what the world was looking up right now from live Wikipedia pageview data (CC0), and records it as a signed observation you can pin beside your first copy. Independent of your file, and re-verifiable by anyone.
signed observation (JSON)
Re-check this exact stamp yourself: open it in the verifier. The verifier fetches the source-of-record and checks the Ed25519 signature against the published key set, with no calls back to us.
Priority of a copy is decided on records.
When a photo is called doctored, a document called backdated, or a dataset called altered after the fact, the fight is about which copy came first and whether it changed. Your own internal file timestamp is necessary, but it is your own record on your own systems, and the other side will say exactly that. A hash notarized at the moment of first receipt by an independent witness, signed then, retained in the signed archive, and re-verifiable years later against a published key, is corroboration that does not depend on anyone taking your word for it. Our records work against us just as well as they work for you: anyone can re-check them, including whoever is challenging you.
Evidence, not a ruling on the source.
Dynamic Feed is a neutral witness, not a court, publisher or adviser. A notarized hash proves that this exact byte sequence existed at notarization time and has not changed since. It does not establish who created the file, whether the content is true, or where it came from, and it does not settle authorship or provenance by itself. Laws, editorial standards and evidentiary rules vary by jurisdiction, and Dynamic Feed is one input beside your own archive and reporting records, not the whole story. Advisory evidence, tamper-evident not more, not a certification and not legal advice.
One API call per source item.
Editorial and archival tooling can mint a signed source-of-record the moment a file lands, hash only, self-serve to scale.