Second Brain GitHub Repositories (2026) · Open Source Tools

Guides and resources for AI engineers: an agents course, five handbooks, a hands-on second-brain project and a vetted reading list.

The fastest, cheapest, most efficient open-source agent harness. Run more than 500 agents on a $10 VPS.

Your Personal Librarian Agent. Ask anything on your computer, organize files, remember important info and files.

AI-native knowledge base & Evernote/Obsidian alternative. Instant all-platform sync, rich notes (tables, mind maps, diagrams, posters), web clipper & MCP. 100% free on Cloudflare or Docker.

Framework for AI agents to build and maintain a digital brain through Obsidian wiki | Memory System for Agents

Beautiful, AI-native markdown IDE and LLM wiki

AI assistant in Telegram that remembers everything and helps you run your life. Self-hosted in one command.

Your Self-Hosted Knowledge Base

Get tasks and ideas out of your head. A free GTD to-do app for desktop and mobile. Works offline, no account needed

Turn your documents into a Markdown wiki you can read, that answers with citations. Works with any LLM provider, Ollama included. CROW classifier routing: 89% right note vs 62%, 2.1× faster ingest, 68% fewer tokens.

QOwnNotes is a plain-text file notepad and todo-list manager with Markdown support and Nextcloud / ownCloud integration.

An on-device LLM understands your entire life, then proactively offers to get your work done through computer use.

Self-maintaining, Obsidian-compatible knowledge base for pi — turn raw sources into an interlinked wiki that compounds. Native Open Knowledge Format (OKF) v0.2.

📝 Glyph is a private desktop workspace for notes, documents, and ideas, with Markdown editing and built-in AI tools.

Local AI-powered document search and editing with first-in-class hybrid retrieval, LLM answers, WebUI, REST API and MCP support for AI clients.

A plain text note-taking assistant

A privacy-first, open-source platform for knowledge management and collaboration.

LeanKG: Stop Burning Tokens. Start Coding Lean.

One private place for everything on your mind. Capture it, write it, plan it. Notes, tasks, inbox and journal, end-to-end encrypted.

Harness as code — the Terraform for AI agents. Define your agent team AND its memory once, deploy to Claude Code, OpenClaw, Cursor, Codex, Gemini, Copilot, Kiro. Declarative .at language + agent-maintained, Obsidian-portable company brains + interactive visualizer.