SiYuan — Privacy-First Self-Hosted Knowledge Management

Introduction

SiYuan is an open-source, privacy-first personal knowledge management system built with TypeScript and Go. It stores all data locally with optional end-to-end encrypted cloud sync, giving you full ownership of your notes and knowledge graph.

What SiYuan Does

• Provides block-level content editing with bi-directional references and backlinks
• Supports Markdown, math equations, diagrams, and embedded content blocks
• Offers a graph view to visualize relationships between notes and blocks
• Includes built-in spaced repetition flashcards for learning
• Delivers real-time full-text search across all notebooks and blocks

Architecture Overview

SiYuan uses a Go backend serving a local HTTP API, with a TypeScript/Electron frontend. Data is stored as JSON files in a flat directory structure on disk. The kernel handles indexing, search, and sync. Cloud sync uses AES-256 encryption before upload, ensuring only you can read your data.

Self-Hosting & Configuration

• Run via Docker or download desktop apps for Windows, macOS, and Linux
• Data stored in ~/.siyuan by default; mount a volume for Docker persistence
• Configure access auth code in Settings > About for remote access security
• Enable S3 or WebDAV sync for encrypted backup to your own cloud storage
• Set environment variable SIYUAN_ACCESS_AUTH_CODE for headless deployments

Key Features

• Block-level granularity lets you reference and embed any paragraph, heading, or list item
• Local-first architecture ensures zero-latency editing with no internet dependency
• End-to-end encrypted sync keeps data private even on third-party storage
• PDF annotation and asset management built into the editor
• Plugin system and marketplace for community extensions

Comparison with Similar Tools

• Obsidian — also local-first but closed-source; SiYuan is fully open
• Logseq — outliner-focused; SiYuan offers both document and outline modes
• Notion — cloud-dependent SaaS; SiYuan is self-hosted and private
• Trilium — similar self-hosted approach but less active development
• Joplin — simpler note-taking; SiYuan has richer block references

FAQ

Q: Is SiYuan really free? A: The core app is free and open-source. Cloud sync via the official service is a paid feature, but you can self-host sync with S3 or WebDAV for free.

Q: Can I import from Notion or Obsidian? A: Yes. SiYuan supports importing Markdown files and has community tools for migrating from Notion and other platforms.

Q: Does it work offline? A: Absolutely. SiYuan is local-first — all editing works offline. Sync happens when connectivity is available.

Q: How secure is the sync? A: All synced data is encrypted with AES-256 on your device before upload. The server never sees plaintext content.

Sources

• https://github.com/siyuan-note/siyuan
• https://b3log.org/siyuan/en/