siyuan

SiYuan is an open-source, privacy-first personal knowledge management system built around fine-grained block-level references and Markdown WYSIWYG editing. It is designed to be self-hosted, with data stored locally in a workspace folder rather than in a proprietary cloud. Core capabilities evidenced in the README include block-level references and two-way links, custom attributes, embedded SQL queries, and a `siyuan://` protocol. The editor is block-style with Markdown WYSIWYG, list outlines, block zoom-in, and support for large documents. It handles mathematical formulas, charts, flowcharts, Gantt charts, timing charts, and staves, plus web clipping and PDF annotation links. Export options cover block references and embeds, standard Markdown with assets, PDF, Word, and HTML, as well as copy-to-WeChat MP, Zhihu, and Yuque. Other features include a table-view database, flashcard spaced repetition, AI writing and Q/A chat via the OpenAI API, Tesseract OCR, multi-tab and drag-and-drop split screen, template snippets, JavaScript/CSS snippets, and a community marketplace. Deployment paths include desktop and mobile apps (Android, iOS, HarmonyOS), package managers, Docker, Unraid, and TrueNAS. The Docker image `b3log/siyuan` supports workspace mounting, lock-screen password, PUID/PGID permissions, OIDC authentication, and language configuration. A built-in CLI provides direct workspace access for notebook listing, full-text and asset search, SQL queries, export, import, and repository/history management, with JSON output and dry-run support. Data is stored in a workspace folder containing assets, emojis, snippets, storage, templates, widgets, plugins, and public data, with notebook documents saved as JSON `.sy` files. The README notes that third-party sync disks are not supported to avoid data corruption, though third-party cloud storage connection is available as a member privilege. The project is licensed AGPLv3 and most features are free, including commercial use, with some features reserved for paid members.