201: The Complete Guide to Building an AI Second Brain

Get AI-Ready with Kyle’s 5-Day Challenge: https://aiwithkyle.com/join Subscribe and turn on notifications to catch the next live stream: https://www.youtube.com/channel/UChlLglbHDASnoGkbjDeHnQg Summary:  Today I'm tackling the problem nearly everyone using AI seriously eventually hits: your tools don't talk to each other. ChatGPT on your phone has no idea what Claude Code did on your desktop, and Codex on your laptop is working blind to both. I walk through how to build a vendor agnostic AI vault, a shared brain made of simple markdown files that any tool can read, so your context stops getting lost between apps. I show you how to get an AI to interview you and build the entire folder structure for you, no technical setup required, and where GitHub and Obsidian actually fit into the picture (hint: Obsidian is for you, not the AI). If you've seen those gorgeous Obsidian graph diagrams floating around and felt like you were missing something, this clears it up. I explain why the vault, not Obsidian, is the actual brain, why GitHub is the smartest way to sync it across devices, and how to keep growing the system over time so it gets more useful the more you use it. Whether you're juggling client projects, personal life admin or a dozen half finished side builds, this gives every AI tool you use the same source of truth. —— Time Stamps —— 0:00 The Problem: Your AI Tools Don't Share Memory 0:36 The Obsidian Vault Hype, Explained Simply 1:30 Why Your AI Context Is Scattered in 2026 2:39 What Is a Markdown File? 4:17 How Obsidian Works and Why the Vault Matters More 5:33 Structuring Your Vault: Personal, Business, Projects 6:35 Let the AI Interview You to Build It 7:14 README, AGENTS.md and CLAUDE.md Explained 9:13 Use Claude Code or Codex: The Interview Prompt 10:02 Pro Tip: Use a Microphone and Just Talk 10:38 Make It a GitHub Repo for a Durable Vault 11:47 Recap: Obsidian Is Optional, Start Now 12:27 Wrap-Up and Free Newsletter — Useful Resources —— Find everything else at https://aiwithkyle.com/