> ## Documentation Index
> Fetch the complete documentation index at: https://3to1go.docs.thesteau.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Central overview

> The always-on receiver that stores encrypted snapshots from your Edges.

Central is the 3to1go app that **receives and keeps** backups. It runs on one always-on host, such as a home server, NAS, or VPS, and every Edge uploads to it.

## What Central does

* **Receives uploads** from Edges in chunks, and verifies each one before storing it.
* **Stores snapshots** as encrypted archive files under `edge_id/edge_instance_id/job_name` in its backup folder.
* **Applies retention**, keeping the most recent snapshots per job and instance.
* **Mints and revokes Edge credentials**, so only Edges you've authorized can upload.
* **Checks integrity** on a schedule, if enabled.
* **Lets you browse, download, and delete snapshots** in its web UI, decrypting downloads in your browser.
* **Sends notifications** to ntfy and runs your own scripts when uploads arrive.

Central never needs your plaintext files. It only handles archives that Edge has already encrypted.

## What it runs

| Component | Purpose |
| - | - |
| `ghcr.io/thesteau/3to1go-central` | The Central app and web UI, on port `6555` |
| `postgres:17-alpine` | Stores snapshot metadata, users, settings, Edge registrations, and credential records |

The example Compose file runs both. See [Install Central](/central/install).

## Folders it uses

| Inside the container | Holds |
| - | - |
| `/backups` | Stored snapshots. Point this at the disk, NAS, or synced folder you want. |
| `/staging` | Uploads in progress |
| `/config` | Central's signing key (`issuer.key`) and trusted certificates |
| `/hook-scripts` | Scripts you upload for [hooks](/central/hooks) |

<Warning>
  Back up Central's `config` folder. `issuer.key` signs Edge credentials; if it's lost, every existing credential stops working and each Edge needs a new one.
</Warning>

<CardGroup cols={2}>
  <Card title="Install Central" icon="download" href="/central/install" />

  <Card title="Configuration" icon="sliders" href="/central/configuration" />
</CardGroup>