index.html

<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Vite + TS</title>
  </head>
  <body>
    <div id="app"></div>
    <script type="module" src="/src/dev/main.ts"></script>
    <script type="module">
      const launchParam = import.meta.env.VITE_LAUNCH_QSPARAM;

      let launchUrl = import.meta.env.VITE_LAUNCH_URL;

      if (!launchUrl.endsWith('/')) {
        launchUrl += '/';
      }

      const localUrl = new URL(import.meta.url);

      let configEncoded = btoa(
        JSON.stringify({
          localUrl: localUrl.origin,
          scripts: [
            {
              name: '@vite/client',
              scriptType: 'module',
            },
            {
              name: 'src/dev/main.ts',
              scriptType: 'module',
            },
          ],
          stylesheets: [
            {
              name: 'src/dev/tokens.css',
            },
          ],
        }),
      );

      location.replace(
        `${launchUrl}?${launchParam}=${encodeURIComponent(configEncoded)}`,
      );
    </script>
  </body>
</html>