---
title: "Artifact integrity"
description: "Every model load can be traced from the downloaded bytes to a released length and SHA-256."
canonical: "https://www.fermionresearch.com/docs/integrity/"
source: "Fermion Research"
---

Docs / Integrity and support

# Artifact integrity

Every model load can be traced from the downloaded bytes to a released length and SHA-256.

## What fermion checks

1. Container structure The file length must match the complete record structure encoded by the container.
2. Manifest length The file length must match the value in `MANIFEST.json`.
3. Manifest SHA-256 The full-file digest must match the released digest.
4. Runner sidecar The prebuilt native binary is checked against its own SHA-256 sidecar before execution.
5. Speech archives A Phonon speech model downloads as a single archive pinned to a released SHA-256 and is verified before it is unpacked.

## Run the checks

```text
fermion info
fermion info --model /data/models/neutrino-8b_v4.bin
```

The command exits 1 for incomplete or altered containers, which makes it suitable for deployment scripts. `--no-checksum` skips only the full hash; structural and length checks still run.

## Recover from an incomplete download

If `fermion info` reports a mismatch, remove the incomplete model snapshot and run the original command again. The downloader resumes or fetches a clean copy into the configured cache.

Source: [https://www.fermionresearch.com/docs/integrity/](https://www.fermionresearch.com/docs/integrity/)