---
sidebar_position: 4
title: Configuration Reference
description: All server.yaml configuration keys with defaults and matching environment variables.
---

# Configuration Reference

BackupX loads `./config.yaml` from the working directory by default. You can override the path with `--config`. Every key can also be set via a `BACKUPX_` prefixed environment variable.

## Full config reference

```yaml title="config.yaml"
server:
  host: "0.0.0.0"             # BACKUPX_SERVER_HOST
  port: 8340                  # BACKUPX_SERVER_PORT
  mode: "release"             # release | debug
  external_url: ""            # BACKUPX_SERVER_EXTERNAL_URL — public Master URL for Agent install scripts

database:
  path: "./data/backupx.db"   # BACKUPX_DATABASE_PATH — embedded SQLite

security:
  jwt_secret: ""              # BACKUPX_SECURITY_JWT_SECRET — auto-generated if empty
  jwt_expire: "24h"           # BACKUPX_SECURITY_JWT_EXPIRE
  encryption_key: ""          # AES-256-GCM key for storage config encryption

backup:
  temp_dir: "/tmp/backupx"    # BACKUPX_BACKUP_TEMP_DIR
  max_concurrent: 2           # BACKUPX_BACKUP_MAX_CONCURRENT
  retries: 3                  # Per-upload rclone low-level retries
  bandwidth_limit: ""         # e.g. "10M" to cap transfers at 10 MB/s

log:
  level: "info"               # debug | info | warn | error
  file: "./data/backupx.log"
```

## Secret generation

If `jwt_secret` or `encryption_key` is empty on first start, BackupX generates a random value and persists it to the `system_configs` table. Keep a backup of `data/backupx.db` — losing it invalidates all existing encrypted storage configurations.

## Environment variables

The environment wins when both file and env are set. All dot-paths become underscores and uppercase:

| Config key | Env variable |
|------------|--------------|
| `server.port` | `BACKUPX_SERVER_PORT` |
| `server.external_url` | `BACKUPX_SERVER_EXTERNAL_URL` |
| `security.jwt_expire` | `BACKUPX_SECURITY_JWT_EXPIRE` |
| `log.level` | `BACKUPX_LOG_LEVEL` |
| `backup.max_concurrent` | `BACKUPX_BACKUP_MAX_CONCURRENT` |
| `backup.temp_dir` | `BACKUPX_BACKUP_TEMP_DIR` |
| `backup.bandwidth_limit` | `BACKUPX_BACKUP_BANDWIDTH_LIMIT` |

## Master external URL

Set `server.external_url` when BackupX is behind Docker, Nginx, a load balancer, or any reverse proxy whose internal Host is not reachable by remote Agents:

```yaml
server:
  external_url: "https://backup.example.com"
```

This value is used when BackupX renders one-click Agent install scripts and docker-compose snippets. It must be reachable from every Agent host. Leave it empty only when `X-Forwarded-Proto` / `X-Forwarded-Host` are reliable and point to the same URL that Agents can access.