Tgc-OutlineBackup

A simple tool to back up Outline via its export feature.

Features

• Export all collections via the Outline API and download the resulting archive.
• Daily scheduled backups or single-run mode (--once).
• Automatic cleanup of old backups based on retention policy.

Requirements

• Java 25 or later.
• A valid Outline API key (set via system property outline.api.key).

Building

On Unix / macOS:

    ./mvnw clean package

On Windows (PowerShell / CMD):

    mvnw.cmd clean package

This produces a -jar-with-dependencies in target/.

Run the application

One-time (single backup) mode:

java -Doutline.api.key=<YOUR_API_KEY> -jar target/Tgc-OutlineBackup-<CURRENT_VERSION>-jar-with-dependencies.jar --once

Scheduled daily backups (runs at configured schedule hour, default 02:00):

java -Doutline.api.key=<YOUR_API_KEY> -jar target/Tgc-OutlineBackup-<CURRENT_VERSION>-jar-with-dependencies.jar

Obtaining an API Key

To use Tgc-OutlineBackup, you need an API key from your Outline account:

1. Log in to your Outline instance
2. Navigate to Account -> API & Apps
3. Generate a new API key

Keep your API key secret

Configuration (via system properties)

Property	Default	Description
outline.api.key	none (required)	Outline API key
backup.dir	./backups	Backups dir
export.format	json	Export format: json / html / outline-markdown
export.include.attachments	true	Include attachments in the export
export.include.private	true	Include private collections in the export
retention.days	30	Days to retain backup exports
schedule.hour	2	Hour of day (0–23) to run daily backup
poll.initial.delay.milliseconds	2000	Initial poll delay when checking operation status
poll.max.attempts	10	Max attempts to poll operation completion
ratelimit.max.attempts	10	Max retry attempts on rate-limit