Build your brain — Brain Comp

An OKF brain — your knowledge written in the Open Knowledge Format — is nothing fancy: a folder of text files on your computer. Each file is one "concept." (A "markdown file" is just a plain text file whose name ends in .md instead of .txt — same typing, nothing special to install.) No database, no app, no account, no payment — just a folder you could email to yourself or zip up later.

1Make one folder and put every concept in it

First, let's make the folder that will be your brain. Pick your computer below and follow the clicks.

On a Mac:

Click the smiley Finder icon in the bar at the bottom of your screen.
In the left sidebar, click Desktop (so the folder is easy to find later).
At the very top of the screen click File, then New Folder.
A new folder appears with its name highlighted. Type my-ai-brain and press Return.

On Windows:

Click the yellow File Explorer folder icon on your taskbar (or press the Windows key and type "File Explorer").
On the left, click Desktop.
Right-click on any empty white space, choose New, then Folder.
Type my-ai-brain over the highlighted name and press Enter.

Now you have an empty folder called my-ai-brain on your Desktop. Next, let's save each concept into it as its own text file.

How to save one concept as a .md file:

Open the free TextEdit app (Mac) or Notepad app (Windows). On a Mac, click the magnifying glass at the top-right, type TextEdit, and press Return. On Windows, press the Windows key, type Notepad, and press Enter.
Mac only — do this once: in TextEdit, click Format at the top, then Make Plain Text. This stops TextEdit from adding hidden formatting.
Copy the text of one concept (from ChatGPT or Claude) and paste it in.
Click File, then Save. When the save box appears, choose your my-ai-brain folder on the Desktop as the place to save it.
For the file name, type the name including the ending — for example profile.md (not just "profile"). The .md at the end is what makes it a markdown file.
If Windows warns you about changing the file type, click Yes. If a Mac box asks whether to use .md or .txt, click Use .md.

Repeat that for each concept. Make one .md file per concept and keep them all loose inside my-ai-brain (no folders inside folders for now — just keep it simple). When you're done it should look like this:

my-ai-brain/
├── profile.md
├── projects.md
├── tools.md
├── voice.md
└── faq.md

Those names are just examples — use whatever concepts you actually wrote. The little lines and branches are just a drawing of "files inside a folder," not anything you type.

What's "frontmatter"? It's the little info block at the very top of each file, fenced between two lines of three dashes (---). It tells an AI what the file is. The only required line is type:. You added these back when you wrote your concepts — for example:

---
type: concept
title: Profile
description: Who I am and what I do
---

If any file is missing this top block, add one now before moving on.

2Add an `index.md` (the table of contents)

OKF has one special file with a reserved name: index.md. Think of it as the table of contents for your brain — a simple list of every other file and what's in it. This lets an AI glance at the list first and decide what to read, instead of reading every file at once.

Make it exactly like you made the others: open TextEdit (Mac, set to Plain Text) or Notepad (Windows), paste in the text below, then File → Save into your my-ai-brain folder with the name index.md. Copy this and change the names/links to match your real files:

---
type: index
title: My AI Brain
description: What's inside this brain
---

- [Profile](profile.md) — who I am and what I do
- [Projects](projects.md) — what I'm working on now
- [Tools](tools.md) — my stack
- [Voice](voice.md) — how I write
- [FAQ](faq.md) — questions I get asked a lot

Each list line follows the same pattern: - [Title](filename.md) — short note. The part in square brackets is the name a human reads; the part in round brackets is the exact file name it points to, so it must match a real file in your folder, spelled the same way.

Now your folder looks like this:

my-ai-brain/
├── index.md      ← the map
├── profile.md
├── projects.md
├── tools.md
├── voice.md
└── faq.md

3Quick consistency check

Open each file one more time and check these. Keeping them the same across every file is what "consistent frontmatter" means — it just helps the AI read your brain reliably.

Every file starts with the --- info block (the frontmatter) and that block has a type: line.
Each block also has a title: and a description: line (not strictly required, but they help the AI a lot).
There are two --- lines around the info block: one on the line above it and one on the line below it, with nothing else around them.
File names are all lowercase with no spaces, and they match the links you wrote in index.md exactly.
The writing inside each file is short and factual — useful background for an AI, not long essays.

✅ Lobe 04 complete when: you have a folder with 5+ concept files and an index.md. Congratulations — that folder is a real Open Knowledge Brain. Next up — Lobe 05: wire it into your agent.

Tip: done beats perfect. You'll improve concepts once you've actually used the brain in Lobe 05 — that's when the gaps show up.

1Make one folder and put every concept in it

2Add an index.md (the table of contents)

3Quick consistency check

2Add an `index.md` (the table of contents)