Write your first concept — Brain Comp

First, three words explained (no tech background needed):

Markdown = just plain text. It's writing the way you'd type a note — no special program, no formatting buttons. If you can type a text message, you can write markdown.
A ".md file" = a plain-text note whose name ends in .md instead of .txt. The .md on the end is just a label that says "this is markdown." That's all a "file type" means here.
Frontmatter = a tiny list of labels at the very top of the file, fenced off between two lines that each contain just ---. It tells your AI what the file is. We'll show you exactly what to type.

Don't worry about making the file yet — Step 5 walks you through it, click by click.

1The anatomy of a concept

Every concept file has two parts: a frontmatter block (the few labels between the two --- lines) and a body (the actual content, written as plain text underneath). That's the whole format.

---
type: profile          ← the frontmatter (labels)
title: About Me
---

I'm Jake — I build...   ← the body (plain markdown)

2The fields

A "field" is just one of those labels at the top (like title:). Only one field is required. The rest are optional but worth adding — they help your AI find and use the concept later.

typerequired

What kind of concept this is — e.g. profile, faq, tools. Your choice of label.

titleoptional

A human-readable name for the concept.

descriptionoptional

One line on what's inside.

tagsoptional

Keywords for grouping and finding it. Type them inside square brackets, separated by commas — e.g. [identity] or [identity, work].

resourceoptional

A web link to a source this concept points at, if there is one.

timestampoptional

When it was written or last updated.

3Fill in the template

Take the first item from your Brain Plan (Lobe 02) and write it. Copy the template below into any text box you like for now (a plain note, an empty document, or even a chat message to yourself), then fill in the blanks. We'll turn it into a real .md file in Step 5 — for now it's just text.

Keep the two --- lines exactly as they are, and keep the spacing — a label, a colon, a space, then your text (like title: About Me).

Template

---
type:
title:
description:
tags: [ ]
---

(write the content here, in plain language — facts your
AI should know, kept tight and useful)

Worked example — profile.md

---
type: profile
title: About Me
description: Who I am and what I do
tags: [identity]
---

I'm Jake — I build and teach practical AI for non-developers.
I run the JakeDoesAI newsletter and the AI Frontier Builders
community.
Keep advice concrete and beginner-friendly.

Write it for your AI, not for a human reader: short, factual, no fluff. One idea per file — if it's growing two heads, split it into two concepts.

4Quick check of your text

Before you turn it into a file, glance over what you wrote:

It opens with a --- line and closes the labels with a second --- line.
It has a type: line (that's the one required label).
Your actual content sits below the second --- line.

5Save it as a `.md` file

Now make it a real file. Pick whichever way feels easiest — they all give the same result:

Easiest — let your AI do it

Paste your finished concept into ChatGPT or Claude (the free web version is fine) and send this exact message:

Save the text above as a downloadable file
named profile.md (plain markdown, nothing changed).

It'll give you a file to download. Click it, and it lands in your computer's Downloads folder. Done.

Or — type it yourself in a free editor

On a Mac: open the TextEdit app → menu Format → Make Plain Text → paste your concept → File → Save → in the name box type profile.md (the .md on the end is what matters) → Save.
On Windows: open the Notepad app → paste your concept → File → Save As → set "Save as type" to All Files → type profile.md as the name → Save.

Use a lowercase name like profile.md — not Profile.MD. Lowercase keeps things tidy and predictable.

✅ Lobe 03 complete when: you have one saved .md file with the labels on top and your content below. That's a real concept — your first building block. Next up — Lobe 04: write the rest and gather them into a brain.

Tip: don't aim for perfect — aim for true and useful. You'll refine every concept once you see how your agent uses it in Lobe 05.

1The anatomy of a concept

2The fields

3Fill in the template

4Quick check of your text

5Save it as a .md file

5Save it as a `.md` file