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

# Introduction

> Capsule is an automated database backup agent for PostgreSQL, MySQL, and MongoDB.

## What is Capsule?

Capsule is a lightweight CLI agent that runs on your server and backs up your databases on a schedule. Every backup is **AES-256 encrypted on your server** before being pushed to Capsule's cloud — we only ever receive ciphertext.

<CardGroup cols={2}>
  <Card title="Quickstart" icon="rocket" href="/quickstart">
    Install the agent and run your first backup in under 5 minutes.
  </Card>

  <Card title="CLI Reference" icon="terminal" href="/cli/auth">
    Full reference for every Capsule command.
  </Card>

  <Card title="Database Guides" icon="database" href="/databases/postgres">
    Setup guides for PostgreSQL, MySQL, and MongoDB.
  </Card>

  <Card title="Security" icon="shield" href="https://trycapsule.xyz/security">
    How Capsule protects your data — and how to verify it yourself.
  </Card>
</CardGroup>

## How it works

1. You install the Capsule agent on the server where your databases run
2. The agent connects to your databases using credentials stored locally — they never leave your server
3. On schedule, Capsule runs the native dump tool (`pg_dump`, `mysqldump`, `mongodump`) on your server
4. The output is AES-256 encrypted locally, then uploaded to Capsule's cloud
5. Backup history and connection status sync to your web dashboard

## Supported databases

| Database   | Versions  | Docker | Remote host |
| ---------- | --------- | ------ | ----------- |
| PostgreSQL | 12+       | ✓      | ✓           |
| MySQL      | 5.7+, 8.x | ✓      | ✓           |
| MongoDB    | 4.4+      | ✓      | ✓           |

**Remote host** means Capsule can back up a database running on a different machine — it connects over the network using the credentials you provide, the same way a database client would. This is a **Pro/Team feature** — Hobbyist and Solo plans can only connect to databases on `localhost` (or a Unix socket). See [Connection limits](/cli/connection#notes) for details.

## Architecture

Capsule uses a **zero-knowledge architecture** — your credentials and plaintext data never reach our servers. See the [security page](https://trycapsule.xyz/security) for a full breakdown and instructions on how to verify this yourself.