siyuan-note/siyuan

SiYuan — a privacy-first, self-hosted personal knowledge management app. Notion / Obsidian alternative with strong Chinese-market adoption.

What it is

A TypeScript + Go knowledge-management app combining block-based editing (Notion-style), Markdown-first storage, bi-directional linking, mind maps, flashcards, and OCR. Self-hostable; Electron desktop + mobile (iOS, Android) + web. End-to-end-encrypted sync via the SiYuan team's commercial cloud, or via your own S3 / WebDAV. AGPL-3.0 licensed.

Key features

Block-based Markdown editor with bi-directional linking.
Mind-map view, flowchart, flashcards (Anki-style spaced repetition).
OCR for image-text extraction.
Multi-platform: Electron desktop (Win, macOS, Linux), iOS, Android, web.
End-to-end-encrypted sync via S3 / WebDAV / SiYuan cloud.
LLM integration with multiple providers (DeepSeek, OpenAI, Ollama, OpenClaw).
AGPL-3.0 licensed.

Tech stack

TypeScript primary on the renderer.
Go on the backend / kernel.
Electron for desktop packaging.

When to reach for it

You want a self-hosted Notion / Obsidian alternative with strong block + Markdown integration.
You want privacy-first with E2EE sync.
You're in the Chinese knowledge-management space — SiYuan has strong adoption there.

When not to reach for it

You're allergic to AGPL.
You want collaborative real-time editing — SiYuan is single-user.

Maturity signal

44k stars, 2.8k forks, AGPL-3.0, actively maintained. The Chinese-market specificity is reflected in the documentation + community.

Alternatives

Obsidian — local-first Markdown notes (closed source).
Notion — managed SaaS.
Logseq — block-based local-first alternative.
Joplin — Markdown-first note-taking.

Wiki: siyuan-note/siyuan