SiYuan, from Yunnan Liandi Technology Co. Ltd., is a local-first personal knowledge manager built to refactor thinking and preserve data ownership. It provides block-level editing, a Markdown WYSIWYG editor, bidirectional links and an interactive graph view for interconnected notes and outlines. The app bundles a SQL-like query engine, spaced repetition, and encrypted sync options. Researchers, writers, and developers who need programmable search and offline control are the primary audience.

What the tool actually does for structured knowledge

The app implements a block-based editing model that treats paragraphs, list items, and images as addressable units, letting users reference or move discrete pieces of content. Editing is offered in a Markdown WYSIWYG interface while bidirectional linking and an interactive graph view visualize relationships. These behaviors support workflows that refactor notes into linked knowledge rather than isolated pages, and they place emphasis on fine-grained composition and referencing.

How it integrates into developer and research workflows

SiYuan runs across desktop and mobile platforms and supports self-hosting via Docker for web access, which suits mixed-device projects and team servers. The app accommodates technical content with LaTeX for formulas and charting tools such as Mermaid for diagrams and Gantt charts. For developers this means documents can include executable-style diagrams and math without leaving the workspace, and server deployment is available for institutional access.

How its data model and search help manage complex information

The internal model exposes unique block IDs and a SQL-like query system that lets technical users filter and assemble content programmatically. That combination enables extracting structured views, building task lists from blocks, or generating targeted exports. A built-in spaced repetition module converts selected content to flashcards for long-term retention, making the tool useful for study workflows alongside archival research projects.

How synchronization and privacy are handled for sensitive data

The app follows a local-first storage philosophy and works offline by default, preserving on-device control of records. When cross-device sync is required, it supports end-to-end encrypted synchronization through S3-compatible storage, WebDAV, or the developer's official cloud, allowing teams or individuals to choose hosted or self-hosted backends. The developer’s focus on privacy is reflected in those options and the local-first design.

SiYuan fits privacy-focused technical users who accept an onboarding investment

SiYuan is a capable option for researchers, writers, and developers who prioritize local control and programmatic querying; it rewards time invested in learning block-based organization and query syntax. User feedback notes a steeper learning curve than simpler note apps, so plan an initial configuration and testing period before migrating large archives or relying on it for mission-critical documentation.