·Anchor

Anchor a file. Standard or Sealed.

Two browser-form flows over the same chain. Pick the mode below, drop a file in, get a tamper-evident receipt that an outside auditor can verify without us — against any public block explorer, in any browser.

Looking for the agent-flow story instead? See the three agent outcomes →

01Which one do I want?

Standard Proof or Sealed Proof.

Same chain, same verifier. They differ in what someone watching the public chain can learn about your file.

Standard Proof

Use when the file is public now, or will be revealed later: released artifacts, public policy snapshots, signed contracts, code releases, revealed bids.

Create a Standard Proof →

Sealed Proof

Use when even confirming a matching file would be sensitive: unrevealed bids, internal policy snapshots, private evidence manifests, legal exhibits, pre-release materials.

Create a Sealed Proof →
02Supported file types

Format-aware fingerprints.

Selective disclosure works for ordinary documents the same way manifest receipts do for agent batches — prove a single page, row, tile, or archive entry without revealing the rest.

FileContent fingerprintSection breakdown
PDFextracted text, normalizedper page
JSONRFC 8785 canonicalper top-level key
CSVRFC 4180 normalizedper data row
Source / textNFC-normalized, line-ending stableper line
ZIP / DOCX / XLSXentry manifestper contained file
Image (JPG/PNG/WebP)raw pixel data, metadata strippedper tile
Anything elsebyte-exact hash onlyn/a

Why this matters. A re-saved PDF, a re-compressed JPEG with metadata stripped, or a CSV re-exported with different line endings still verify against the content hash — even though the byte-exact hash changes.