OpenCairn Setup Guide

You need: A supported Claude Code account. For most individuals, that means a Claude Pro or Max subscription.

1. Install Git

Windows: Download from git-scm.com/downloads/win - default options, just click through. Claude Code on Windows requires this.

Mac: xcode-select --install (or brew install git if you have Homebrew).

Linux: sudo apt install git (Debian/Ubuntu) or sudo dnf install git (Fedora).

2. Install Claude Code

Mac/Linux:

curl -fsSL https://claude.ai/install.sh | bash

Windows (PowerShell):

irm https://claude.ai/install.ps1 | iex

No dependencies needed — the installer is a standalone binary that auto-updates in the background.

“Not in your PATH” error? (Windows)

1. Win + R → type sysdm.cpl → Enter
2. Advanced tab → Environment Variables
3. Select Path under User variables → Edit → New
4. Paste the path it told you (e.g. C:\Users\YourName\.local\bin)
5. OK everything → restart PowerShell

3. Authenticate

claude

It opens a browser. Sign in with your Anthropic account. Then check claude.ai → Settings → Privacy. Under Anthropic’s current consumer data policy, if “Improve Claude for everyone” is on, Anthropic may use consumer Claude Code sessions for model improvement and retain them for five years. Turning it off means 30-day retention for Claude Code data.

Type /exit to quit for now.

4. Clone the Template

git clone https://github.com/OpenCairn/OpenCairn.git ~/Files
cd ~/Files
git remote rename origin template
chmod +x .claude/scripts/*.sh

~/Files is your vault — everything lives here. The remote rename lets /update pull future template improvements.

4.5. Configure Environment

Mac/Linux — add to ~/.bashrc (Linux) or ~/.zshrc (Mac):

export VAULT_PATH="$HOME/Files"
alias cc='cd ~/Files && claude'

Then reload: source ~/.bashrc (or source ~/.zshrc).

Windows (PowerShell):

# Run once:
[Environment]::SetEnvironmentVariable("VAULT_PATH", "$HOME\Files", "User")
# Add to $PROFILE for the alias:
function cc { Set-Location ~/Files; claude }

Now you can type cc from anywhere to launch Claude Code in your vault.

5. Run OpenCairn Setup

cc

(Or cd ~/Files && claude if you haven’t reloaded your shell yet.)

Then run:

/setup

OpenCairn checks the environment, then interviews you to personalise CLAUDE.md and create the context-file stubs.

6. Install Obsidian

Stay in the same Claude session. Type:

Download and install Obsidian, then open ~/Files as a vault.

7. Seed Your Vault

Still the same session. Work through these one at a time:

Write a deeper context file (clients, team structure, workflows - the stuff CLAUDE.md didn’t cover):

I want to create a detailed context file about my business operations. Ask me questions one at a time, then write it up in 07 System/.

Start a real project:

/start-project

Pick something you’re actually working on right now.

Capture a process from your head:

I’m going to describe how we onboard a new client. Ask me questions one at a time, then write it up as an SOP in the right folder.

Save your session:

/park

8. Tomorrow

Open your terminal, type cc, then:

/pickup

Everything from today is there. That’s the system.

Daily Commands

Staying Current

The template gets regular updates - new commands, bug fixes, cross-platform improvements. To pull the latest:

/update

This updates OpenCairn infrastructure — commands, scripts, and the Codex rendering — without touching your CLAUDE.md, settings, or vault content. See Keeping OpenCairn Current for details.

Tips

Plan Mode: Press Shift+Tab twice before asking Claude to do something. It’ll discuss its approach before making changes - good for learning how it thinks.

Don’t just ask for outputs. The real value is back-and-forth:

“Let’s brainstorm…” “What am I missing here?” “Can you ask me clarifying questions about…” “Let’s workshop this…”

The conversation is the thinking. Claude asking you questions and you refining your answers is often more valuable than the final document.

Everything compounds. Each file you create becomes context for future sessions. The more you put in, the smarter it gets about your business.