> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fact0.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Verification and exports

> Check chain consistency and exported file signatures.

## Audit verification

Use the Audit view or authenticated `GET /v1/verify`. Verification checks hashes and preceding links in insertion sequence, including links outside a selected timestamp window. Late-arriving records must not create a false break merely because their timestamps fall outside that window.

New core records use a versioned SHA-256 canonical JSON recipe documented with the API source. It binds immutable public event fields, including tenant identity, actor/resource types and the preceding hash. Timestamps are normalized to PostgreSQL microsecond precision before hashing. Records cannot be rewritten through a repair/re-anchor route.

## Evidence exports

Download a PDF or evidence ZIP from the authenticated Audit view. Instance setup generates a persistent Ed25519 signing key. Record its public key separately:

```sh theme={null}
python3 scripts/export-public-key.py
```

Then check a ZIP against that trusted value:

```sh theme={null}
pip install cryptography
python3 scripts/verify-export.py evidence.zip --public-key '<trusted public key>'
```

A key embedded in an archive is insufficient by itself: an attacker could replace both the contents and that key. The verifier compares the archive key to the separately supplied trusted key and checks the PDF and verification JSON signatures.

PDF and evidence reports summarize recorded audit activity; they are not a database backup. Copy/download full captured values from the inspector, and use [PostgreSQL backup and restore](https://github.com/fact0-ai/fact0/blob/main/docs/guides/self-hosting.mdx) to preserve the full instance. The ZIP signs the PDF and verification JSON; its README and explanatory text are informational.

## What a passing result means

A valid chain establishes consistency of the records checked under the documented hash recipe. A valid export signature establishes that the signed file bytes match the trusted instance key. Neither proves that every agent action was captured, that the source agent reported truthfully, or that a database/key administrator could not replace the whole history.

Replay is a reconstruction of recorded activity. Fact0 does not rerun external tools or certify regulatory compliance.