Open, verifiable proof — built for the EU AI Act era

The Compliance Proof Auditors Need

Pick what you're anchoring, or drop a file. It's fingerprinted in your browser — nothing leaves your device — and you get a receipt anyone can verify.

1Fingerprint on your device
2Anchor to a public record
3Anyone can verify

“Anchor” = a timestamp written to a public record no one can backdate or erase.

Open protocol · open-source verifier · Foundation-stewarded · verify without trusting us.
Try it — no signup
Drop any file. You get a receipt in ~3 seconds — nothing leaves your device.
Drop a file to anchor it
…or click to browse · fingerprinted locally, nothing uploads
Verify:
Create and verify — free, no signup. Only the 64-char fingerprint is ever anchored — never your file.
Live · the public record
documents of record — cryptographically anchored, and counting

We don’t just claim tamper-evidence. We run it at scale, in public, every day.

Official public records — the EU Official Journal, EUR‑Lex, UK legislation, the US Federal Register, SEC EDGAR and more — fingerprinted on our side and anchored continuously.

What’s in the record

160+ official sources — anchored every day.

Live document counts, straight from the public record. Hover a row to pause.

Why it matters

The evidence your General Counsel can hand to a regulator.

A self-written log proves nothing to a third party. A LedgerProof dossier is independently verifiable — the difference between “trust us” and “check it yourself.”

LedgerProof Dossier · AI Transparency
Ways to anchor

Anchor anything — pick a starting point.

An AI output, a document, an agreement, your art, evidence, a log, a dataset — or drop any file in the tool above. Fingerprinted on your device, hash-only.

Running an AI product? Free Article 50 readiness scan Check if your AI can prove what the EU AI Act requires — before 2 August. No signup. Open the scanner →
Pricing

Free to create and verify. Paid to manage and prove.

Start free with the drop-a-file tool above. When you need to register AI systems, monitor them, and export an auditor-ready dossier — that’s the Vault.

Free

Drop-a-file

€0 forever
  • Anchor any file
  • Verify any receipt
  • No signup, nothing uploads
Try it now
Vault · for teams

Register & prove

from €290/mo
  • Register the AI systems you must prove
  • Anchored evidence, on the record
  • Auditor-ready dossier export
Start free trial
Enterprise

Regulated & scale

Custom
  • SSO & self-host options
  • Certified evidence packages
  • Priority support
Talk to us
Building AI?

First receipt in five minutes.

Emit a tamper-evident receipt for any output. Nothing leaves your box but a SHA-256. Verifying is free and keyless.

Read the quickstart →
# install
$ pip install ledgerproof

# emit a receipt — artifact hashed locally, hash-only egress
from ledgerproof import LedgerProof
lp = LedgerProof(publisher_id="LEI:529900H…", deployer_country="DE")
receipt = lp.publish_ai_article_50(
    artifact="the AI output text…",   # hashed on your box
    ai_system_id="support-bot", content_category="text",
)
print(receipt.sequence, receipt.verify_url)