borg-anchor

borg-anchor

Borg backups with Bitcoin timestamping. Your data lives on forever.

Overview

borg-anchor combines BorgBackup (deduplicating archiver) with Bitcoin timestamping to create backups with cryptographic proof of existence.

Your Data → Borg Backup → Bitcoin Anchor → Immortal Proof

Features

• Deduplication - Only store changes, not duplicates
• Compression - Efficient storage with lz4/zstd
• Encryption - Optional AES-256 encryption
• Bitcoin Timestamping - Immutable proof your backup existed
• Chained Proofs - Each backup linked to previous via UTXO chain

Installation

npm install -g borg-anchor

Prerequisites

• BorgBackup installed
• blocktrails CLI for Bitcoin anchoring
• Node.js 18+

Quick Start

# Initialize a new backup repository
borg-anchor init ~/backups

# Configure your Bitcoin key
cd ~/backups
git config nostr.privkey <your-hex-privkey>

# Create your first backup
borg-anchor backup ~/mydata --name first-backup

# View all projects and backups
borg-anchor info

# List backups in current project
borg-anchor list

# Verify a backup is anchored
borg-anchor verify first-backup

# Restore a backup
borg-anchor restore first-backup /tmp/restore

Commands

Command	Description
info	Dashboard of all projects (CLI)
dashboard	Web dashboard (localhost:3077)
init [path]	Initialize borg repo and config
backup <source>	Create backup and anchor on Bitcoin
list	List backups and trail status
verify <archive>	Verify backup is anchored
restore <archive> [dest]	Restore backup to destination
show	Show config and trail status

Options

Init Options

Option	Default	Description
--repo <name>	repo	Borg repository directory name
--encryption <type>	none	none, repokey, repokey-blake2
--network <net>	tbtc4	btc (mainnet) or tbtc4 (testnet)

Backup Options

Option	Default	Description
--name <name>	backup-YYYY-MM-DD	Archive name
--no-anchor	-	Skip Bitcoin anchoring
--dry	-	Dry run (don't broadcast)

How It Works

• Borg creates a deduplicated backup with a unique fingerprint (SHA-256)
• The fingerprint is anchored on Bitcoin via a chained UTXO trail
• Anyone can verify the backup existed at the anchored time

┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│ Your Files  │ ──▶ │ Borg Backup │ ──▶ │  Bitcoin TX │
│             │     │ fingerprint │     │  timestamp  │
└─────────────┘     └─────────────┘     └─────────────┘

Files

After initialization, your backup directory contains:

~/backups/
├── .borg-anchor.json   # Configuration
├── .blocktrail.json    # Bitcoin trail state
├── .git/               # Git repo (holds keys)
└── repo/               # Borg repository

Projects are also registered globally for the dashboard:

~/.borg-anchor/
└── projects.json       # List of all borg-anchor projects

Verification

To verify a backup:

# Get the fingerprint
borg info ~/backups/repo::my-backup | grep fingerprint

# Check it's anchored
borg-anchor verify my-backup

The fingerprint in your backup must match the fingerprint recorded on Bitcoin.

Networks

Network	Flag	Use Case
tbtc4	--network tbtc4	Testing (free, default)
btc	--network btc	Production (real Bitcoin)

License

AGPL-3.0

Links

• Documentation
• GitHub
• npm
• BorgBackup
• solid.live