SiYuan

SiYuan is an open-source knowledge workspace designed for organizing thoughts, notes, and information with a focus on privacy. It operates on a block-based editing model where individual content units can be linked, referenced, and reorganized at a granular level. The tool supports Markdown formatting, bidirectional linking between blocks, and includes features like flashcards, databases, and integration with AI systems to assist with tasks like writing, translation, and summarization. Data is stored locally on the user's device, and multi-device synchronization uses end-to-end encryption to maintain privacy. The tool can be self-hosted through Docker deployment or synchronized across devices.

SiYuan is developed by siyuan-note and released under the AGPL 3.0 license. The application is written in TypeScript and supports local-first operation, meaning it functions without internet connectivity. It can be deployed as a personal server or used across multiple devices while maintaining encrypted synchronization. The platform also supports interaction with AI agents through its architecture.