How it works
Versions, fingerprints and the on-chain record behind every Obsol link.
The idea
A document you send can change after it leaves your hands. Obsol gives every document a permanent link and records each of its versions on a public blockchain, so any copy can later be checked against the record.
1. Fingerprint
When you drop a file, your browser computes its SHA-256 hash — a 64-character fingerprint. Changing a single byte of the file produces a completely different fingerprint.
2. Anchor
Anchoring writes a compact record to Solana: the document id, the version number and the fingerprint. The transaction timestamp proves that this exact version existed at that moment.
No personal data, no file name and no file content is written on-chain. The file itself never leaves your browser; only the fingerprint is sent.
3. Embed
Put the permanent link getobsol.com/v/your-document and its QR code in the document — usually the footer — before you send it. See Embedding the link.
4. Update
When the document changes, anchor the new file under the same id. It becomes v3, v4… The link never changes.
5. Verify
Anyone holding a copy opens the link or scans the QR, drops the copy, and gets one of three verdicts. See Verifying a copy.