> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bytesell.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Sections and blocks

> Default content, global zones, and block rendering rules.

The `section { }` and `block { }` grammar belongs to Slurp. See
[Sections and blocks](/slurp/guides/sections-and-blocks) for the schema, the
setting kinds and merge semantics. This page covers the ByteSell layer: default
content, global zones, and the conditions under which a merchant's block
renders.

## Default content

`templates/<page key>.json` supplies the content a store starts with when the
theme is installed. From then on the merchant owns the content and the file is
not consulted again.

```json site/templates/index.json theme={null}
{
  "sections": [
    { "id": "hero", "type": "Hero", "settings": { "heading": "My store" } },
    { "id": "grid", "type": "ProductGrid", "settings": { "limit": 8 } },
    { "id": "faq",  "type": "Faq", "disabled": true,
      "blocks": [
        { "id": "q1", "type": "faq_item",
          "settings": { "question": "Do you offer refunds?" } }
      ] }
  ]
}
```

| Key        | Required | Notes                                                 |
| ---------- | -------- | ----------------------------------------------------- |
| `type`     | yes      | A string matching `sections/<type>.slurp`.            |
| `id`       | no       | Unique within the page.                               |
| `settings` | no       | Omitted keys fall back to the schema default.         |
| `disabled` | no       | Present but not rendered. The merchant can enable it. |
| `blocks`   | no       | Nested block instances, same shape.                   |

A duplicate `id` within one page fails the publish. The editor addresses a
section as `(page, id)`, so a repeat makes both unreachable. The same id on two
different pages is permitted.

## Global zones

A named group hosts chrome shared across pages. Place it in a layout:

```slurp site/layouts/base.slurp theme={null}
{layout "@layouts/shell"}
  {sections "above_header"}
  {sections "header"}
  <slot />
  {sections "footer"}
{/layout}
```

Zones are not declared. A zone exists when a defaults file exists: adding
`templates/groups/header.json` creates a zone named `header`, which
`{sections "header"}` renders.

```json site/templates/groups/header.json theme={null}
{
  "sections": [
    { "id": "nav", "type": "Header" }
  ]
}
```

<Note>
  The page's own `{sections}` is stripped on entry to a component or layout, so
  it resolves only in a page. Named groups are not stripped, so a layout can
  compose them. Put `{sections}` in the page and `{sections "header"}` in the
  layout.
</Note>

Merchants can hide a zone per page.

## Block rendering rules

Both of the following fail silently.

### A section targeting `@theme` must host `{blocks}`

`@theme` makes the merge accept every theme block type. If the markup then draws
children by hand, the merge accepts a type the markup never draws: the
merchant's block persists in the database and the page renders without it.

```slurp theme={null}
---
section {
  name: "Links"
  blocks { @theme }
}
---
<ul>
  {blocks}
</ul>
```

The converse also applies. A section that draws its blocks by hand must not
target `@theme`, or it advertises types it cannot render.

### A theme block cannot use `{fetch}`

Publishing rejects any file under `blocks/` containing a `{fetch}` at any depth:

```
blocks/product.slurp: a theme block cannot use {fetch} - it is evaluated before
the block renders, so it would silently produce nothing. Fetch from the browser
instead.
```

The fetch pass runs before blocks resolve, so the block renders empty with no
diagnostic. Fetch from the browser with the SDK instead.

## Files under `blocks/`

* The block type is the filename, not the schema's `name`. `name` is the label
  in the merchant's palette.
* Filenames are restricted to `[A-Za-z0-9_-]`. `blocks/a/b.slurp` is ignored:
  the renderer rejects the `/`, so the block would be addable but never render.
* A file under `blocks/` with no `block { }` schema is ignored rather than
  rejected, so partials can live there.

## Section budgets

A section that exceeds a render budget fails the whole page rather than
disappearing from it. A page silently missing one section is diagnosed as a
content problem.

See [Limits](/themes/reference/limits).