your ai second brain on claude code
an Obsidian vault that Claude Code operates: you dump thoughts and documents in plain English, it does the filing, linking and remembering. about 10 minutes to set up, no technical experience.
setup guide
- open code.visualstudio.com
- press the big blue download button
- open the file it downloads and install it
- open VS Code and leave it open
what is this?
a free editor from Microsoft. you will not write code in it. it is the window Claude works inside, and the place you talk to it.
on a Mac, drag Visual Studio Code into Applications first, then open it from there.
- open obsidian.md
- download it and open it
what is this?
a free note-taking app. your second brain is just a folder of text files; Obsidian is where you read them as pretty, linked notes. Claude does the writing, you do the reading.
- open claude.ai and make an account
- pick Pro, $20 a month. already have a free account? upgrade at claude.ai/settings/billing
do i really have to pay?
yes, this is the one part that costs money. the free plan does not include Claude Code at all.
and it is the only cost: the second brain itself adds nothing on top. running it is the same usage bucket as everything else you do with Claude Code.
- in VS Code, click the Extensions icon in the left bar
- search for
Claude Code, by Anthropic, press Install - click the Claude icon that appears, press Sign in, log in with the account from step 3 in the browser window that opens
something went wrong
no browser opened? quit VS Code and open it again, then press the Claude icon and try the sign-in once more.
shown a code instead of being sent back? copy it into the panel where it asks.
- make an empty folder somewhere on your computer, name it whatever you want
- in VS Code: File, Open Folder, pick it, and trust the folder when it asks
- in Obsidian: Open folder as vault, pick the same folder
what is this?
now both apps are looking at the same place. VS Code is where Claude writes; Obsidian is where you read. one folder, two windows onto it.
can’t find the vault button? in Obsidian the menu is File, then Open vault, then Open folder as vault.
this is the whole build. in the Claude panel in VS Code, paste this and let it work.
- it will ask permission a few times. say yes
- about two minutes later it says done, and the folders appear on the left
what is it actually building?
six folders and a contract. inbox/ is where you dump anything unsorted, projects/ holds things with a finish line, areas/ the ongoing parts of your life, wiki/ the notes Claude writes and maintains about you, archive/ what is done, tmp/ scratch.
the contract is CLAUDE.md: you dump raw thoughts, Claude does the filing, linking and summarizing. it reads that file at the start of every session, which is why the system keeps working next week without you re-explaining it.
- solve your next real task here instead of in the chat app: analyzing a document, planning something, any research
- when a task teaches it something about you, say: “save what you learned about me to the wiki”
- when a task repeats, say: “save this as a skill”, and it becomes a slash command you run with one line
tips from daily use
talk to it with your voice. a dictation tool makes dumping five minutes of context painless, and context is what makes the answers good.
the win is compounding memory: every task leaves facts behind, and the next task starts from them. after a few weeks it knows your company, your documents and your plans, and you stop repeating yourself.
keep big, long-running projects in their own folders outside the vault; tell the second brain where they live so it can read them when needed. everything else, from experiments to 30-minute jobs, belongs inside.
if you get stuck
the things that actually go wrong, taken from the questions people ask under the video.
the terminal says “command not found: claude”
installing the Claude Code extension in VS Code does not give you the claude terminal command. the extension keeps a private copy for its own chat panel. that catches almost everyone, and it is not a broken setup.
to get the command, install Claude Code itself:
# macOS or Linux curl -fsSL https://claude.ai/install.sh | bash # Windows PowerShell irm https://claude.ai/install.ps1 | iex
then close the terminal window completely and open a new one. skipping that is the second most common reason it still says not found. check it worked with claude --version.
still not found on a Mac? your PATH is missing the folder, so run these two lines:
echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.zshrc source ~/.zshrc
claude doctor prints a full health report if you are still stuck. and if you would rather never touch a terminal, the Claude Code desktop app does the same job with buttons.
one thing worth knowing before you install anything: Claude Code needs a paid Claude plan (Pro or higher) or an API account. the free claude.ai plan does not include it, so it can install perfectly and still refuse to sign you in.
what does this actually cost to run?
Claude Code comes with a Claude subscription: Pro at $20/month, Max at $100 or $200/month. usage is included, there is no per-run charge. the free plan does not include Claude Code at all.
inside Claude Code, /status tells you whether you are on a subscription or an API key, and /usage shows how close you are to your plan limit.
prices and free tiers move. these were checked in August 2026.
is "--dangerously-skip-permissions" safe?
it does exactly what the name says: it turns off the ask-before-acting prompt, so Claude can edit files and run commands on your machine without checking with you each time. that is why it is fast, and that is the whole risk.
the honest version: in a project folder like this one, where you know what is inside and nothing valuable is nearby, it is a reasonable trade. pointed at your whole home folder, or at a repo you have not read, it is not.
the safer default is to drop the flag. claude "/prime" does the same work and asks first. you approve a few things at the start, then it stops asking about the same kinds of actions.