Anki Sync Server Enhanced

Production-ready Docker image for self-hosted Anki sync server with backups, monitoring, dashboard, and security features.

Why This Image?

The official Anki project provides sync server source code but no pre-built Docker images. This project provides:

• Zero build time - Pre-compiled for amd64, arm64, and arm/v7
• Auto-updates - Daily builds automatically track the latest Anki release
• Enterprise features - Backups, monitoring, alerts, and security out of the box
• NAS-ready - Works on TrueNAS SCALE, Unraid, Synology, and any Docker host

Features

Quick Start

docker run -d \
  --name anki-sync \
  -p 8080:8080 \
  -e SYNC_USER1=user:password \
  -v anki_data:/data \
  chrislongros/anki-sync-server-enhanced:25.09.4-1

Then configure your Anki client to sync to http://your-server:8080/

Docker Compose

services:
  anki-sync-server:
    image: chrislongros/anki-sync-server-enhanced:25.09.4-1
    container_name: anki-sync
    ports:
      - "8080:8080"   # Sync server (HTTP)
      - "8443:8443"   # Sync server (HTTPS, if TLS_ENABLED)
      - "8081:8081"   # Dashboard (optional)
      - "9090:9090"   # Metrics (optional)
    environment:
      - SYNC_USER1=alice:password1
      - SYNC_USER2=bob:password2
      - TZ=Europe/Berlin
      - BACKUP_ENABLED=true
      - METRICS_ENABLED=true
      - DASHBOARD_ENABLED=true
    volumes:
      - anki_data:/data
      - anki_backups:/backups
    restart: unless-stopped

volumes:
  anki_data:
  anki_backups:

Web Dashboard

Enable with DASHBOARD_ENABLED=true and access at http://server:8081/

Features:

• Overview - Server status, uptime, user count, data size, sync operations
• Users - Per-user statistics with data size and last sync time
• Backups - List backups, create new backups with one click
• Logs - View sync, auth, and backup logs with color-coded entries
• System - Disk usage, memory usage, load average

Protect with basic auth using DASHBOARD_AUTH=admin:password

Configuration Reference

Core

Backups

S3 Upload

Monitoring

Notifications

Security

TLS / HTTPS

Built-in TLS support via Caddy reverse proxy. Three modes available:

Mode 1: Let's Encrypt (automatic)

docker run -d \
  -p 80:80 -p 443:443 \
  -e SYNC_USER1=user:password \
  -e TLS_ENABLED=true \
  -e TLS_DOMAIN=anki.yourdomain.com \
  -e [email protected] \
  -v anki_data:/data \
  -v anki_config:/config \
  chrislongros/anki-sync-server-enhanced:25.09.4-1

Mode 2: Manual certificates

docker run -d \
  -p 8443:8443 \
  -e SYNC_USER1=user:password \
  -e TLS_ENABLED=true \
  -e TLS_CERT=/config/certs/fullchain.pem \
  -e TLS_KEY=/config/certs/privkey.pem \
  -v ./certs:/config/certs:ro \
  -v anki_data:/data \
  chrislongros/anki-sync-server-enhanced:25.09.4-1

Mode 3: Self-signed (local/testing)

docker run -d \
  -p 8080:8080 -p 8443:8443 \
  -e SYNC_USER1=user:password \
  -e TLS_ENABLED=true \
  -v anki_data:/data \
  chrislongros/anki-sync-server-enhanced:25.09.4-1

Then configure clients to use https://your-server:8443/

Note: Self-signed certificates will show browser warnings. For local networks, you may prefer using HTTP or a proper certificate.

CLI Tools

# User management
docker exec anki-sync user-manager.sh list
docker exec anki-sync user-manager.sh add john
docker exec anki-sync user-manager.sh add john mypassword
docker exec anki-sync user-manager.sh reset john newpass
docker exec anki-sync user-manager.sh hash mypassword
docker exec anki-sync user-manager.sh stats

# Backup management
docker exec anki-sync backup.sh
docker exec anki-sync restore.sh --list
docker exec anki-sync restore.sh --list-s3
docker exec anki-sync restore.sh backup_file.tar.gz
docker exec anki-sync restore.sh --s3 backup_file.tar.gz

Client Configuration

Desktop (Windows/Mac/Linux)

1. Open Anki
2. Go to Tools → Preferences → Syncing
3. Set custom sync server to: http://your-server:8080/
4. Click Sync and enter your credentials

AnkiDroid (Android)

1. Open AnkiDroid
2. Go to Settings → Sync → Custom sync server
3. Set sync URL: http://your-server:8080/
4. Set media URL: http://your-server:8080/msync/
5. Sync with your credentials

AnkiMobile (iOS)

1. Open AnkiMobile
2. Go to Settings → Sync → Custom server
3. Enter: http://your-server:8080/
4. Sync with your credentials

Tip: Enable built-in TLS with TLS_ENABLED=true or use a reverse proxy (Traefik, Caddy, nginx) for secure remote access.

Prometheus Metrics

Available at http://server:9090/metrics when METRICS_ENABLED=true:

Docker Secrets

For secure credential management:

services:
  anki-sync-server:
    image: chrislongros/anki-sync-server-enhanced:25.09.4-1
    environment:
      - SYNC_USER1_FILE=/run/secrets/anki_user1
    secrets:
      - anki_user1

secrets:
  anki_user1:
    file: ./secrets/user1.txt  # Contains: username:password

Image Sources

NAS Installation

• TrueNAS SCALE: See truenas/README.md
• Unraid: Add unraid/my-anki-sync-server.xml to the templates-user folder

Troubleshooting

Can't connect to server:

• Ensure port 8080 is exposed and not blocked by firewall
• Check container logs: docker logs anki-sync
• Verify the sync URL ends with / (e.g., http://server:8080/)

Sync fails with large collections:

• If using a reverse proxy, increase client_max_body_size (nginx) or equivalent
• Set MAX_SYNC_PAYLOAD_MEGS environment variable if needed

Authentication issues:

• Ensure username doesn't contain special characters
• Check auth log: docker exec anki-sync cat /var/log/anki/auth.log
• Try resetting password: docker exec anki-sync user-manager.sh reset username newpassword

Dashboard not loading:

• Ensure DASHBOARD_ENABLED=true is set
• Check port 8081 is exposed
• View logs: docker logs anki-sync | grep dashboard

Building Locally

# Auto-detect latest Anki version
docker build -t anki-sync-server-enhanced .

# Specify Anki version
docker build --build-arg ANKI_VERSION=25.09.4 -t anki-sync-server-enhanced:25.09.4-1 .

Credits

Built from the official Anki sync server by Ankitects.

License

AGPL-3.0 - © 2026 Christos Longros - see LICENSE