---
title: Install
description: Install missing toolchain tools at the pinned versions. Does not upgrade what is already there.
order: 2
---

# vibe21-system-install

Installs only the tools that [vibe21-system-check](/docs/vibe21-system-check) reported as missing. Already-present tools stay as they are, even if they are older than the pin.

## When to use it

Use it when the check reports `MISSING`, or when the agent offers install after a check and you confirm.

Do not use it to upgrade. That is [vibe21-system-update](/docs/vibe21-system-update).

## How to run it

```
/vibe21-system-install
```

The agent tells you which missing tools will be installed at which pinned versions, then waits. Nothing is installed until you confirm.

On macOS, Homebrew is installed first — Git needs it. The official Homebrew installer may ask for a **sudo** password. On Windows, winget is installed first. Linux skips both.

## What happens

- Only missing tools are installed. The pin lives with the skill.
- After install, the check runs again so new `PATH` entries (fnm, pnpm) are visible.
- If `gh` is present but not logged in, you run `gh auth login` yourself. The agent does not.

When the tools are in place, create the site with [vibe21-web-new](/docs/vibe21-web-new).