Prerequisites

Before creating your first experiment, make sure your environment meets the following requirements.

Node version

Node 20 is the minimum. Node 24 is recommended.

The generated project's .nvmrc is set to 24. Running an older Node version will cause compatibility issues with pnpm 10.

Install and manage Node versions with nvm:

nvm install 24
nvm use 24
node --version   # v24.x.x

Every generated project ships with a .nvmrc file. Running nvm use inside the project root will switch to the correct version automatically.

Windows users

Use nvm-windows instead of nvm.

Node 16 is incompatible

The system default Node on some machines is 16. pnpm 10.x requires Node 18 at minimum. Always run nvm use 24 before any pnpm or node commands.

pnpm

pnpm 10.x required

The generated project's pnpm-lock.yaml uses lockfile format v9, which is only compatible with pnpm 10.x. Using pnpm 9.x or earlier will fail --frozen-lockfile installs.

Install via Corepack (recommended):

corepack enable
corepack prepare pnpm@latest --activate
pnpm --version   # 10.x.x

Install via npm (alternative):

npm install -g pnpm
pnpm --version   # 10.x.x

Why pnpm 10? The lockfile format changes between major versions. Projects committed with a v9 lockfile (pnpm-lock.yaml from pnpm 10.x) will fail on pnpm 9.x or below.

Playwright

Playwright is only needed if you enable E2E testing during scaffolding (the CLI prompts you).

If you answered Yes to E2E at scaffold time, the CLI installs browsers automatically after generating your project. You do not need to do anything extra.

To install browsers manually (e.g. after cloning an existing E2E-enabled project):

cd my-experiment
pnpm playwright install

This downloads Chromium, Firefox, and WebKit to ~/.cache/ms-playwright. Plan for approximately 300 MB of disk space.

Default browser

The generated playwright.config.js uses Desktop Chrome only. You do not need all three browsers for smoke testing.

Verification

Run these commands to confirm your environment is ready:

node --version   # v20.x.x or v24.x.x
pnpm --version   # 10.x.x

Once both pass, continue to Installation.