Chat with an agent that knows your notes, search by meaning, and see your vault grouped into topics. Runs on Ollama, OpenAI, Anthropic, and more.
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 groups them into the topics your vault is actually about, 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.
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 and pick it for search and for the graph to unlock semantic search and topics that read what your notes say, not just how they link; add an AI provider to enable the agent. See the getting started guide.
Out of the box, none of your data leaves your machine. Your notes only go to the providers you configure, and there is no telemetry — see privacy. The one other network request is a daily update check that fetches this plugin's manifest.json from GitHub and sends nothing about you; turn it off under Settings → General → Check for updates.
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. Much of the code is written with AI coding agents; we review, test, and stand behind every change, and commits and pull requests say when an agent was involved.