The folder setup and the one prompt that make every AI session start where the last one ended. It works in Obsidian (free, also for work) or in any folder of plain text files.

Hi, it's Ivo.

1. Make the vault

Download Obsidian from obsidian.md. It's free, including for work. Sync is an optional paid add-on. You don't need it to start.
Click Create new vault, call it Brain (any name works) and put it in a normal folder, like Documents.
That folder is the vault. Every note inside it is a plain text .md file. Any editor can open it, and so can any AI tool that reads files.

2. The folder setup: 5 folders

Folder	What goes in it
`00 Inbox`	quick notes, links and ideas you haven't sorted yet
`01 Projects`	one folder per project with an end date: a website, a launch, a move
`02 Areas`	the parts of your work that never end: marketing, money, admin
`03 Archive`	finished projects. Move them here, don't delete them
`04 Reference`	things you look up again: how-tos, prompts, checklists

The numbers keep the order the same on every computer.

3. The session note (template)

One note per work session, saved in the project's folder: 01 Projects/<project>/<date> <topic>.md

```

2026-10-16 · Website contact form

Done

Decisions

_ (why: _)

Checked

(how you know it works)

Open

(the first thing to do next session) ```

Four headings, nothing else. Done is what changed. Decisions are the choices you'd forget by next week, with one line on why. Checked is what you actually tested. Open is where the next session starts.

4. The end-of-session prompt

Paste this as the last message of every AI session, in any tool:

Paste this

"Before we stop, write a short session note in Markdown for my vault. Use four headings: Done, Decisions, Checked, Open. Under Decisions, add one line on why. Under Open, put the first thing to do next session. Keep it under 200 words. Leave out passwords, API keys, tokens and anyone's personal data. If you can write files, save it as 01 Projects/[project]/[today's date] [topic].md. If you can't, give me the note so I can paste it into the vault."

Next time, start the session by telling the tool which project you're on, so it reads the latest note in that folder first.

5. How each AI gets to it

Tools that work with files on your computer (Claude Code, Codex and other coding agents): point them at the vault folder. They read and write the notes directly.
Chat apps in the browser can't see a folder on your computer. Paste the latest note at the start of the chat, or upload it.
Agents on a server: Obsidian has an official command line (Obsidian CLI) and Obsidian Headless (open beta), which Obsidian describes as a way to give agentic tools access to a vault without access to your full computer.

6. Three safety rules

No passwords, API keys, tokens or bank details in the vault. Every agent you connect can read every note. Keys belong in a password manager or in a .env file outside the vault.
No private data about clients or other people. Write "a client" or "the agency", not names, emails or phone numbers.
Give each tool only the folder it needs, and keep a backup. Community plugins get full access to your files, so install only the ones you trust.

As of October 2026. Menus and betas change, so check Obsidian's help pages if something looks different.

Sources: obsidian.md/help/data-storage · obsidian.md/pricing · obsidian.md/blog/free-for-work · obsidian.md/help/cli · obsidian.md/help/headless · obsidian.md/help/plugin-security

Starter Vault: one memory for every AI you use