# A shared brain for me and my AI tools

*2026-11-12 · Fariz Wibisono*

My notes live in an Obsidian vault of plain Markdown files that both I and my AI assistants can read and update. How it is organised, and the rules that keep it useful instead of messy.

Every AI session used to start from zero. I would explain the project again, the decisions again, what I did yesterday again. The assistant was capable; it just had no memory of me.

So I gave us a shared one: a notes vault in [Obsidian](https://obsidian.md/), kept in Git, that I read in the app and my AI tools read as plain files.

## Why plain Markdown

Obsidian stores everything as ordinary Markdown files in folders. That one choice is what makes the whole thing work. I get links, search and a nice editor; an AI assistant gets text files it can read and edit; Git gives both of us history, so any change can be reviewed or undone.

## How it is organised

The vault follows two well-known systems:

- **PARA**: Projects (things with an end), Areas (ongoing responsibilities), Resources (reference material) and an Archive.
- **Johnny Decimal** numbering, so every folder has a stable address.

On top of that there is an inbox for quick capture, a daily log, and maps of content: index notes that link to every project, every decision and every working session.

Each project note works like a ticket, with a status that says whether it is up next or in progress. A decision gets its own dated note: what was decided, why, and what it affects.

## The part that makes it work with AI

At the root there is one instruction file for assistants. It does not restate the rules; it tells them where the rules live and what to read, in order:

1. The rulebook: folder layout, note templates, what never to do.
2. A small set of memory notes: durable facts and preferences.
3. A note called "next session", where the last session left off.
4. The latest daily log.
5. Only the projects that are currently active.

Then it says the most important thing: if what you need is not in those reads, ask instead of guessing.

The ground rules are short. Never delete my notes without confirmation. Use the templates. Update the index notes when creating something. Date every session and decision. When in doubt, ask.

## What changed

Sessions start where the last one ended, because the assistant reads the "next session" note first and updates it at the end. Decisions stop getting re-argued, because they are written down with their reasons. And the vault became more useful to me, too: writing for a reader that needs clear structure turned out to be good for the human reader as well.

> **What I would tell someone starting.** Start with plain files and a reading order, not a clever tool. The structure is what makes notes useful to both you and your AI, and you can change tools later without losing anything.