AssetMapper & frontend assets

New Symfony web apps often ship AssetMapper - versioned assets without a mandatory Webpack/Vite pipeline. Your FE brain still applies; the defaults just differ from Laravel's Vite stub.

Mental model

• Put CSS/JS under assets/
• Import map (importmap.php / assets/app.js) tells the browser how modules resolve
• Twig helpers dump the right <link> / <script type="importmap"> tags
• In prod, assets get digested/versioned

It's closer to "native ES modules + a smart map" than to a full bundler - until you need one.

Typical Twig hooks

{% block stylesheets %}
  <link rel="stylesheet" href="{{ asset('styles/app.css') }}">
{% endblock %}

{% block javascripts %}
  {% block importmap %}{{ importmap('app') }}{% endblock %}
{% endblock %}

Exact helpers depend on your Flex recipe version - peek at the generated base.html.twig. When something 404s, check assets/ and php bin/console debug:asset-map (if available in your version).

When you want Vite / Encore

Some teams still use Webpack Encore or a custom Vite setup - especially for React/Vue SPAs living inside Symfony.

Rules of thumb:

• AssetMapper - classic MPA, light JS, Stimulus-ish islands
• Encore / Vite - heavy SPA, JSX/TSX pipelines you already know

Don't fight the project's choice on day one. Match whatever package.json / importmap.php already implies.

Compared to Laravel

Laravel	Symfony (default webapp)
resources/js + Vite	assets/ + AssetMapper
@vite([...])	importmap() / asset()
npm run dev always	optional until you outgrow the map

As you can see, the FE skill transfers - the default toolchain is the surprise.

Next: forms, validation, and CSRF without reinventing $_POST.

Best,

-- ł.