Smart Second Brain

Smart Second Brain is an Obsidian plugin for people who want to find and work with information across their notes. It connects search and a topic graph with an AI assistant that can use your vault as context.

• Note and PDF search: Find text inside notes and PDFs, narrow results by tag or folder, or use semantic search when you remember an idea but not the wording. Full-text search works without an AI provider; semantic search needs an embedding model.
• Topic graph: Explore related notes in groups, adjust how broadly they're grouped, and focus on one topic to see its smaller parts. The graph works without an AI provider, while embeddings let it group notes by their content as well as their links.
• Edits you review: Agents can read notes, draft additions and stage changes for your approval inside the note. Chats and shared agent memories live as files in your vault, where you can search, edit or delete them.
• Live charts and plugin tools: Ask for charts, tables or dashboards based on queries over your notes, then save them as panes or embed them in notes. Agents support MCP servers and plugin APIs, with ready skills for Dataview, Tasks and TaskNotes.

The plugin is free and open source under the MIT license, and works in Obsidian on desktop and mobile. Ollama and oMLX support fully offline AI on your computer without an account, keeping notes local. Cloud connections include OpenAI, Anthropic, OpenRouter and OpenAI-compatible services; with those connections, AI processing happens outside your machine.