EteSync

EteSync is a privacy-focused synchronization service built around zero-knowledge, end-to-end encryption, designed for syncing personal information such as calendars, contacts, tasks, and notes. The self-hostable server component (Etebase Server, formerly referred to as EteSync 2.0) provides the backend that EteSync clients connect to.

Key Features

• Zero-knowledge end-to-end encryption, so the server cannot read user data
• Sync backend for calendars, contacts, tasks, and notes via EteSync clients
• Encrypted, tamper-resistant change journal for history, review, and replay of changes
• Django-based administration for managing users and server configuration
• Supports reverse-proxy deployments and production setups with TLS termination

Use Cases

• Privately sync contacts and calendars across mobile and desktop devices without exposing data to the server operator
• Run a personal or family sync service with full control over storage and backups
• Maintain an auditable history of changes to synced data for recovery and rollback

Limitations and Considerations

• Requires compatible EteSync/Etebase client applications; it is not a generic CalDAV/CardDAV server
• Production deployments need careful TLS and reverse-proxy configuration to preserve correct host headers

EteSync is a solid choice for users who want modern encrypted synchronization with strong privacy guarantees. Self-hosting the Etebase Server provides full data ownership while keeping the convenience of multi-device sync through supported clients.