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How it works

One link in the file. The truth on-chain.

Anchor each version of a document, put its permanent link and QR in the footer, and send it anywhere. Every copy can be checked later against the record — by anyone, in seconds.

Verify a copy

Free for your first 3 documents · anchored on Solana

What the recipient sees

Three clear verdicts, no interpretation

CURRENT

The copy matches the latest anchored version.

SUPERSEDED

The copy is a real earlier version — a newer one exists.

UNRECOGNIZED

The fingerprint matches no anchored version: altered or never registered.

NewSUPERSEDED verdicts are live

Use cases

Any document that keeps changing after you send it

Obsol works with any file. If an outdated copy of it can cost you, anchor it.

CVs & portfolios

Recruiters keep the PDF you sent months ago. Their copy now tells them a newer one exists.

Certificates & diplomas

Issuers anchor each certificate; anyone can check it was not altered or revoked.

Contracts & offers

Every draft is timestamped. The other side always knows which version is final.

Price lists & menus

Old price sheets forwarded by email flag themselves as SUPERSEDED.

Policies & manuals

Staff print a procedure once; the QR tells them when it has been revised.

Specs & datasheets

Suppliers and partners can confirm they build against the current revision.

Why the verdict can be trusted

Proof that does not depend on us

Hashed in your browser

A SHA-256 fingerprint is computed locally. Verifying a copy never uploads it.

Anchored on a public chain

Each version is written to Solana with a timestamp no one can edit.

Tamper-evident

Change one character and the fingerprint no longer matches: the copy shows UNRECOGNIZED.

Survives Obsol

The record lives on-chain. Anyone can re-check a fingerprint against it without our servers.

What the record contains

your-document · v2
sha-256 9f86d081…0f00a08
2026-10-07 14:02:11 UTC
document
your-document
version
v2
fingerprint
9f86d081…0f00a08
network
Solana

API

Anchor from your own systems

On the Business plan: add one HTTP call to the pipeline that produces your documents.

# anchor a new version (only the hash is sent)
sha=$(sha256sum price-list.pdf | cut -d' ' -f1)
curl -H "content-type: application/json" \
     -d "{\"docId\":\"price-list-2026\",\"hash\":\"$sha\"}" \
     https://getobsol.com/api/register

# → {"docId":"price-list-2026","version":"v3",
#    "hash":"9f86d0…","explorer":"https://explorer.solana.com/tx/…"}
# check any copy by its fingerprint
sha=$(sha256sum copy.pdf | cut -d' ' -f1)
curl https://getobsol.com/api/hash/$sha

# → {"match":{"docId":"price-list-2026","version":2},
#    "current":{"version":3}}   → SUPERSEDED