---
title: "Theme Customization"
manual: "Render guides"
version: "0.44"
permalink: "https://docs.typo3.org/permalink/t3renderguides:theme-customization"
source: "Developer/ThemeCustomization.rst"
rendered: "2026-09-23T14:52:35+00:00"
---

# Theme Customization {#theme-customization}

The theme provided by this package is prepared to be integrated into the TYPO3
documentation website. Templates are written in [Twig](https://twig.symfony.com/) and uses components
provided by [phpDocumentor/guides](https://github.com/phpDocumentor/guides). The theme is using [Bootstrap](https://getbootstrap.com/) as a
base framework. You can find the theme in `packages/typo3-docs-theme`.
Templates can be found in `packages/typo3-docs-theme/resource/template/`.

To customize the components provided by [phpDocumentor/guides](https://github.com/phpDocumentor/guides) you have to follow
the directory structure of the templates provided by this package. Every template
can be overwritten by creating a new template with the same name in the same
directory. The template engine will automatically use the new template.

In the template you always have the current `node` available. This
node is the element that is currently rendered. The node is an instance of
`\phpDocumentor\Guides\Nodes\Node`. Every template has a different specialized
node. Consult the template of the node to see which properties are available.

When you are creating a template for a node that is a container (like a chapter)
you can access the children of the node by using `node.children`. This is an
array of nodes. You can iterate over this array to render the children using the
`render_node` function. This function will render the node using the correct
template.

## Build Sources {#build-sources}

To build the public assets execute the following commands:

```shell
ddev ssh
cd packages/typo3-docs-theme
npm ci
npm run build
```

Or use the custom ddev commands:

```shell
ddev npm-ci
ddev npm-build
```

## Debug assets {#debug-assets}

You can build the assets for debugging with the following commands:

```shell
ddev ssh
cd packages/typo3-docs-theme
npm ci
npm run debug
```

Or use the custom ddev commands:

```shell
ddev npm-ci
ddev npm-debug
```

The generated assets are copied directly into `Documentation-GENERATED-temp/_resources`
and source maps are not removed. Upon inspection in the browsers web developer
tools you can therefore see in which source scss file certain styles were
defined. Before committing you must run `cd packages/typo3-docs-theme && npm ci && npm run build`
and commit the regenerated asset files in
`packages/typo3-docs-theme/assets/` and
`packages/typo3-docs-theme/resources/public/`.

CI enforces this via the `check-built-assets` workflow: every pull request
that touches `packages/typo3-docs-theme/` is rebuilt and fails if the
committed assets diverge from a fresh build. For Dependabot pull requests the
`dependabot-rebuild-assets` workflow performs the rebuild, commits the result
to the Dependabot branch if it changed anything, and then enables auto-merge for
a patch or minor bump, so no manual rebuild is required there. A rebuild that
fails leaves the pull request open without auto-merge.