Start here
Install MindrianOS
Never opened a terminal? Good, this is built for you. Pick your computer once and follow the stack from 00 to 4. Every command sits in a window with a Copy button and a plain-English caption. The detail and troubleshooting are below if you hit a snag.
When you first get MindrianOS, you want to it running on your machine without fighting your terminal, so you can you can start working in minutes, not hours.
In plain terms
You can run Larry inside Claude Desktop, Cowork, or ChatGPT through MCP, no command line. It gives you Larry and the Brain, but not the full suite (the Data Room and all the commands live in the terminal app). Set up the MCP path instead. Otherwise, the steps below take a few minutes, even your first time.
Get Node.js.
Node.js is a small free program the installer runs on. Most computers do not have it yet, so this is the step people miss. Download the macOS installer (LTS) from nodejs.org, open it, and click through.
Download Node.jsAlready have it? Open your terminal and check:
If it prints a version like v22.3.0, you are ready. Nothing, or an error? Install Node first with the button above, then come back.
Open the terminal, then install Claude Code.
A terminal is just a plain text window where you paste a line and press Enter.
Press Cmd + Space, type "Terminal", and press Enter.
Then install Claude Code, the app Larry lives in. Paste this and press Enter:
This installs Claude Code. Sign in when it opens.
You need a paid Anthropic plan (Pro, Max, Team, Enterprise, or Console). The free tier cannot run Claude Code.
Install MindrianOS with one command.
Paste this into the terminal and press Enter. About two minutes. It finds Claude Code, registers the marketplace, and installs the plugin.
What is npx?
Open Claude and tell Larry the problem.
Run this inside a project folder, then describe what you are working on in plain words. Or run /mos:new-project and Larry builds your room from the conversation.
Turn on the Brain for a free key.
Sign in with Google for a free 30-day key (no credit card), then connect it inside Claude:
The plugin works fully without it. The key plugs in the shared teaching graph behind Larry.
Check it worked.
Inside Claude Code, run:
If the command list appears, MindrianOS is working. That is it, you are in.
Updating
From a terminal:
npx @mindrian_os/cliOr from inside Claude Code:
/plugin marketplace update
claude plugin update mos@mindrian-marketplaceTwo names, do not mix them up.
@mindrian_os/cli. The plugin name inside Claude Code is mos@mindrian-marketplace.Windows: the PATH fix
Windows is the one to read carefully.
Right-click to paste in Command Prompt (Ctrl+V does not work there). To fix "claude is not recognized", the installer put Claude in C:\Users\YourName\.local\bin and you need to add it to PATH:
$env:Path += ";C:\Users\YourName\.local\bin"set PATH=%PATH%;C:\Users\YourName\.local\binTo make it permanent: Windows key → "Environment Variables" → edit the user Path variable and add both C:\Users\YourName\.local\bin and C:\Users\YourName\AppData\Roaming\npm, then reopen the terminal. If Git is missing, run winget install --id Git.Git -e --source winget and reopen the terminal.
Troubleshooting
"Marketplace not found"
Use the one-command installer, which handles the connection: npx @mindrian_os/cli. Or add it manually inside Claude Code:
/plugin marketplace add jsagir/mindrian-marketplace
/plugin install mos@mindrian-marketplace"git is not found" (Windows)
Git is required for the marketplace. Install it, reopen the terminal, and retry: winget install Git.Git.
Do not use sudo with npm.
sudo causes permission problems that are hard to undo. Never prefix an npm install with sudo.