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Stop Using Obsidian. This Simple Second Brain Setup Actually Works (Andrej Karpathy + Claude Cowork)
⏱ 26 min video · 3 min read4 Jun 2026
TL;DR
Creator Chris argues that Obsidian-based second brain setups are overcomplicated and proposes a minimal 5-folder, 3-file system inspired by Andrej Karpathy's self-documenting knowledge base idea. The system uses Claude Co-work to automatically convert raw files into a structured wiki, requiring almost no manual maintenance.
Key points
1
Obsidian is just a markdown editor — you do not need it to build a functional second brain; a simple local folder structure works just as well
2
The 'Simple Brain' setup has 5 folders (raw, wiki, archive, prompts, projects) and 3 files (claude.md, agents.md, readme.md), downloadable from GitHub
3
AI automatically processes files dropped into the raw folder and converts them into a structured wiki, then archives the originals — no manual curation needed
4
A scheduled daily task in Claude Co-work can run the translate.md prompt automatically, making the entire system self-maintaining
5
The system can be extended with automations: voice memo transcription via Whisper, YouTube/podcast transcript ingestion via yt-dlp, and weekly wiki synthesis summaries
Actionable insights
→
Download the Simple Brain GitHub repo, unzip it, and open it as a project in Claude Co-work — no complex install steps required
→
Drop any readable file (PDF, CSV, JSON, HTML, markdown) into the raw folder, then run the translate.md prompt to auto-generate your wiki entries
→
Set up a daily scheduled task in Claude Co-work pointing to the Simple Brain project with the instruction to run the translate prompt — this fully automates wiki creation
→
Use git (or GitHub) to version-control your second brain folder, giving you full history and enabling team collaboration
→
Create separate Simple Brain instances per project or business unit rather than one monolithic brain to keep things manageable
Notable quotes
“You don't need to start off by building something that's this complex. You can just start off with a simple folder structure and a set of text markdown files.”
“You don't have to maintain any of this system really. The AI is doing it for you.”
“Simple brain sounds a bit dumb but I kind of like that in the name.”
Worth watching?
⏭️
Worth watching the full video?
The full setup is covered thoroughly here — skip the video and follow the steps directly from this summary, then grab the GitHub repo linked in the description.
Saved you some time? The creator still deserves a like.
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