.astral files are HEEx-first static templates. They can be used as pages, layouts, and local components.

Components

Place local components under the configured component directory, components/ by default:

<!-- components/pill.astral -->
<span class="pill">
  {render_slot(@inner_block)}
</span>

Use local components with HEEx syntax:

<.pill>Elixir</.pill>

Pages

.astral pages live in pages/:

---
assigns = assign(assigns, :title, "Home")
---

<h1>{@title}</h1>
<.pill>Static HTML</.pill>

The setup block is Elixir. It receives assigns and should return updated assigns when adding values.

Layouts

.astral layouts receive the same assigns as EEx layouts:

<!doctype html>
<html lang="en">
  <body>
    <main data-route={@route}>{@content}</main>
  </body>
</html>

HEEx syntax

Use Phoenix HEEx conventions:

<h1>{@title}</h1>

<ul>
  <li :for={item <- @items}>{item}</li>
</ul>

<p :if={@draft}>Draft</p>

Slots use HEEx slot rendering:

<div class="card">
  {render_slot(@inner_block)}
</div>

Browser assets

<style> and <script> blocks are extracted into Volt's asset graph:

<style>
  .hero { padding: 4rem; }
</style>

<script lang="ts">
  document.querySelector(".hero")?.classList.add("ready");
</script>

Astral removes those blocks from the server-rendered HTML template. Volt builds and serves them as first-class browser modules.