---
url: /gst-manager-acellemail/features/file-integrity.md
description: >-
  Understand the advisory HMAC-SHA256 file-integrity checks in GST Manager for
  AcelleMail — statuses, Auto-Sync on Admin Page Load, and when to act.
---

# File integrity

GST Manager quietly keeps an eye on its own installed files. Using **HMAC-SHA256** signatures, it
knows what its files *should* look like and tells you when something has drifted — for example
after an upgrade, a manual edit, or an incomplete upload. It's an **advisory** check: it surfaces
drift so you can decide what to do, and it **never disables the plugin**. You'll find it on the
**Integrity & Updates** tab.

![The Integrity & Updates tab showing file status](/gst-manager-acellemail/img/gst-file-integrity-status.png)
*GST Manager → Plugin Settings → Integrity & Updates*

::: info What "advisory" means
The check is a heads-up, not a lock. It won't stop the plugin from running and it isn't
tamper-proof — treat it as an early warning that your files changed, then confirm the change was
expected.
:::

## Reading the status

The tab shows one of these, so you can tell at a glance whether anything needs attention:

* **Everything in sync** — files match the recorded baseline; nothing to do.
* **Sync required** — one or more files differ; the panel lists the changes so you can review them.
* **All files verified — HMAC signatures valid** — the signatures checked out.
* **:n files tracked · Last snapshot: :date** — how many files are covered and when the baseline
  was last recorded.
* **No checksum baseline yet…** — nothing has been recorded to compare against yet; the first
  baseline is created for you.

## Auto-Sync on Admin Page Load

The **Auto-Sync on Admin Page Load** toggle lets GST Manager re-baseline itself automatically:
when it detects a mismatch while you're on an admin page, it records the new state as the current
baseline. This is the self-healing behaviour — after a **legitimate edit or upgrade**, the status
returns to *in sync* on its own without you clicking anything.

Leave it on if your files only ever change through expected updates. Turn it off if you'd rather
review every change yourself before the baseline moves.

## When to act

The check runs **only in the admin area** — never on customer-facing pages — so your subscribers
never see it and it never gets in their way.

* **Everything in sync / All files verified** → nothing to do.
* **Sync required right after an update or edit you made** → expected drift; it self-heals (or you
  can let Auto-Sync re-baseline it).
* **Sync required when you didn't change anything** → worth a closer look. Review the listed
  changes; if they're unexpected, re-upload a clean copy of the plugin and contact support.

::: tip Pair it with your backups
Integrity checks tell you *that* files changed, not that your data is safe. Keep your normal
backups — see [Backup & restore](/gst-manager-acellemail/backup-and-restore).
:::

## Related pages

* [Updating](/gst-manager-acellemail/updating) — where the Integrity & Updates tab also lives
* [Backup & restore](/gst-manager-acellemail/backup-and-restore) — snapshots taken before each update
* [Troubleshooting](/gst-manager-acellemail/troubleshooting) — when something looks wrong