Your Smart Second Brain is a free and open-source Obsidian plugin that makes your vault smarter: better search, an interactive knowledge graph, and an AI assistant that actually knows your notes.
Search surfaces your notes, the graph reveals how they connect, and the assistant can draw on both when answering. Search and the graph work right away with no AI provider. Connecting one unlocks the full agent. Runs on desktop and mobile.
smartsecondbrain.dev has a demo video, the features, setup guides, and documentation.
- Search that combines keyword matching with meaning, so you find the note you were thinking of rather than the one you typed (how it works)
- Smart Graph that groups your vault by topic and draws the connections you never linked by hand (how it works)
- Agents that read and write your notes, with skills, memory, MCP, and integrations with your other plugins
Install Smart Second Brain from Obsidian's community plugins and enable it. Search and the Smart Graph work immediately, with no configuration.
Add an embedding model to unlock semantic search and graph clustering; add an AI provider to enable the agent. See the getting started guide.
Out of the box, nothing leaves your machine. The only network requests are to the providers you configure, and there is no telemetry — see privacy.
- Report a bug or request a feature here
- Ask a question in the Q&A
- Share a skill, agent, or workflow in Show and tell
- Pull requests welcome. CONTRIBUTING.md has the development setup and how we handle AI-assisted contributions; AGENTS.md has the architecture, commands, and conventions
We initially built this as a university project. That's long finished, but we keep developing it in our spare time, as an experimental playground for state-of-the-art AI and as a tool for the Obsidian workflow we're passionate about.