title: How to set environment variables from within package.json?
body: <p>How to set some environment variables from within <code>package.json</code> to be used with <code>npm start</code> like commands?</p>
  
  <p>Here's what I currently have in my <code>package.json</code>:</p>
  
  <pre class="lang-json prettyprint-override"><code>{
    ...
    "scripts": {
      "help": "tagove help",
      "start": "tagove start"
    }
    ...
  }
  </code></pre>
  
  <p>I want to set environment variables (like <code>NODE_ENV</code>) in the start script while still being able to start the app with just one command, <code>npm start</code>.</p>