Welcome back to the AI Edge weekly newsletter!
This week, we’re covering one of the hottest topics in AI: How to build your AI second brain.
This is one of the most valuable AI workflows that anyone can set up, and it only takes a few minutes if done properly.
By the end of this read, you'll have a fully functional context and memory system that captures what you learn, stores it in one place, and can be used to build other AI workflows on top of it.
As always, after our main anchor piece, stick around for the Midweek Edge for the week's AI news, and our Looking Ahead section where we compile the top AI research.
Let’s get right into things!
Table of Contents
AI Second Brain Explained
For this AI second brain build, we’ll be using a combination of Claude Code x Obsidian.
Obsidian = To store all notes locally
Claude Code = To automate the process of storing and extracting data
Miles’ Personal AI Second Brain
Why build this system
As humans, we only have so much mental bandwidth.
We often forget things, sometimes it's hard to connect ideas, and ultimately, we can only keep track of so much.
By using this Claude Code x Obsidian context system, you're essentially freeing up mental bandwidth and allowing your second brain to connect, visualize, and interpret an infinite amount of text.
The true power here is that you can use this to store anything.
Real use cases
AI tooling memory system - instantly transfer preferences/context across AI tools
Article storage - store online articles & research in one place
Daily journaling - Local storage for daily journaling with maximum privacy
You can also use this ultimate storage system as the foundation to build other AI workflows - like Claude Skills.
Building Your AI Second Brain (step-by-step)
Download Obsidian at obsidian.md (100% free)
Create a "Vault" - which is just a folder on your computer where everything gets saved as plain text.
Pro tip: Create various vaults for work and personal.
Open Claude Code in the Claude desktop app.
Click "Select Folder" and choose your new Obsidian vault.
Paste in Karpathy's LLM Wiki system prompt, free here:[gist.github.com/karpathy/442a6bf555914893e9891c11519de94f]
After sending this prompt, Claude will then start building your AI second brain system.
Your prompting input should look like this
5. Building The Database
After inputting the initial system prompt above, Claude Code will then ask you for some data points to start populating your second brain.
This is where you can input notes, text & other files to start populating your database.
Some ideas for sourcing data to input:
Export data from any notes apps you may use (like Notion)
Ask your AI tools to give you information about yourself so you can inject it into your second brain.
If you have articles, bookmarks, ideas, etc., go ahead and input them now - this is the time to get at least some initial data in your second brain, and you can always add to it later.
That's it! Your AI second brain is now fully set up and ready to run.
Note: To get a visual representation of your notes as shown above, simply open Obsidian and click the graph icon in the left sidebar ribbon, or open the Command Palette (
Ctrl/Cmd + P) and search "Open graph view."
Graph view command in Obsidian
How To Use Your AI Second Brain (+ Prompts)
Once it's set up, you can manage the system in three ways:
Ingest
Open Claude Code, attach the vault, then prompt Claude:
"I just added [X]. Please ingest it into my second brain wiki."
Claude then reads it, writes a summary, and updates the index within Obsidian.
Query
To query your vault, just open Claude Code and make sure your Obsidian Vault folder is attached - then start prompting.
Example prompts
"What have I saved about [topic], and where do my sources disagree?" "I'm writing about [topic]. What have I already said about it, and what's the angle I haven't used yet?"Clean up
Every few weeks, ask Claude to health-check the wiki.
Copy this:
Run a health check on my wiki.
1. Contradictions. Where do two pages disagree?
2. Stale claims. What's been overturned by a newer source?
3. Orphans. Which pages have nothing linking to them?
4. Gaps. Which concepts come up repeatedly but have no page yet?
5. Next steps. What should I read or add to fill the holes?
List findings by priority. Don't fix anything until I say so.
Getting The Most Out Of Your Second Brain
Install the Obsidian Web Clipper browser extension
This makes it very easy to save notes while on a web page.
Build plugins
Inside Claude, you can build custom plugins and skills to optimize your second brain workflows.
For example: Building a custom Claude Skill that automatically summarizes certain data from your second brain in a format you like.
Avoid context bloat
One of the biggest flaws with this system is context bloat (aka bloating your desktop with local files).
To avoid this, we recommend storing only important notes and data and running the health check prompt linked above regularly.
One more habit: keep work and personal in separate vaults.
The creator of this system, Andrej Karpathy, recommends it, and we've found the same.
Mixing too many ideas across personal, work, and other areas of your life can result in poor output quality when prompting the Wiki in Claude.
Midweek Edge
Our manually curated list of the most important news updates across AI, robotics & tech.
Moonshot AI Releases Kimi K3
Independent testing places Kimi K3 behind only Fable 5 and GPT-5.6 Sol overall, while Arena currently ranks it #1 for frontend coding.
An excellent model for design and coding, and definitely a huge leap forward for open-weight intelligence.
Fable 5 on Paid Plans
Fable 5 is now included in all Claude Max and Team Premium plans, with up to 50% of weekly usage.
Pro and Team Standard users can continue using Fable 5 with usage credits, and Anthropic is also giving away a one-time $100 credit (claim your credits now by opening Claude Desktop).
Google Launches Gemini 3.5/3.6 Family
Google just released three new Gemini models:
→ Gemini 3.6 Flash for coding, reasoning, and everyday work
→ Gemini 3.5 Flash-Lite as the faster, cheaper option for high-volume tasks
→ Gemini 3.5 Flash Cyber for finding software vulnerabilities
Try the new models now in Google AI Studio: https://aistudio.google.com/prompts/new_chat
New: Grok in Excel
Grok is now available as a free Microsoft Excel plug-in.
It can explain selected data, write formulas, run scenarios, create charts, and pull context from connected email or files without leaving the workbook.
Available through Microsoft Marketplace.
Grok Build Open-Sourced
xAI has officially open-sourced Grok Build, its coding agent and terminal-based development interface.
Users can now inspect how the system assembles context and dispatches tool calls, then modify the underlying agent harness for their own workflows.
Looking Ahead
Our manually curated list of the top AI trends, research, workflows & more.
AI Adoption Data
AI may feel mainstream, but global use is still concentrated among a minority of users.
From our research and online sources, we found:
78% of people have never used AI.
2.2% of US households have a paid AI subscription.
0.15% of the population has ever used an AI agent.
If you’re reading this, you are still extremely early.
Loop Engineering → Graph Engineering
Last month, Loop Engineering went viral and showed how AI agents can keep working without being prompted at every step.
Now, the conversation is shifting to Graph Engineering: connecting several loops to watch over each other.
We put together a simple guide to Graph Engineering. Send this prompt to Claude Code, and it will teach you the basics of graph engineering:
Chinese AI Models Research
Chinese models now handle ~58% of the AI tokens routed by US companies.
The rise of Kimi, Qwen, and DeepSeek suggests companies are pivoting to open-weight models for cost-efficiency purposes.
Better models, lower prices, and easier switching could push more AI users toward using different models for different tasks.
Opus 5 Incoming
Multiple leaks point to a possible release of Claude Opus 5 either this week or next week.
Anthropic has not confirmed the model or launch date, so this remains a watch item until an official announcement.
Closing out
If you made it this far, thank you for reading, and we hope you found this week’s edition valuable.
If you enjoy reading, please forward our newsletter to someone you think would benefit from it.💙
Our promise to you: Every Wednesday, at 7 am EST, we’ll cut through the AI noise and send you human-curated AI content to make sure you stay ahead.
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