Installing pnpm on macOS with npm (Not Homebrew)

When working with Node.js on macOS, many developers default to installing tools like pnpm via Homebrew. While convenient, this approach ties pnpm to your system rather than your Node.js environment. If you're using a Node version manager such as fnm (Fast Node Manager), it's better to install pnpm via npm so that it is scoped to the Node.js version instead of being installed globally on your machine.

Why not use Homebrew for pnpm?

Homebrew installs pnpm system-wide, which means: - It doesn't respect the Node.js version you're using. - You may run into mismatched environments when switching Node versions. - Updates are tied to Homebrew rather than your Node manager.

The better way: Install pnpm via npm

Since fnm manages Node.js versions per project or per shell, installing pnpm through npm ensures it is version-scoped. Here's how:

# Ensure you’re using fnm and have a Node.js version set
fnm use --install-if-missing 18

# Install pnpm using npm (tied to this Node.js version)
npm install -g pnpm

Now, whenever you switch Node.js versions with fnm, you can install the corresponding pnpm for that version if needed. This keeps your setup isolated and avoids conflicts.

Verifying the installation

Check that pnpm is installed and tied to your Node.js version:

pnpm -v
node -v

Both should work seamlessly under the version controlled by fnm.

✅ With this setup, pnpm is not a global system binary from Homebrew---it's scoped and version-aware, perfectly aligned with how fnm manages Node.