---
title: "Building assets"
manual: "TYPO3 Core Contribution Guide"
version: "main"
permalink: "https://docs.typo3.org/permalink/t3contribute:build"
source: "Build/Index.rst"
rendered: "2026-09-26T04:50:59+00:00"
---

# Building assets {#build}

This page explains building assets like JavaScript and CSS files.

For the most part, the TypeScript, JavaScript and SCSS sources are contained in
`Build/Sources`. These are compiled to target files, usually located in:

-   CSS: `typo3/sysext/*/Resources/Public/Css`
-   JavaScript: `typo3/sysext/*/Resources/Public/JavaScript`

If you make changes to the source files, you can build locally using
[runTests.sh](https://docs.typo3.org/permalink/t3contribute:runtests-sh):

```bash
Build/Scripts/runTests.sh -s build
```

Note you can also use `npm` \+ `nvm` locally, if you are proficient with setting this up locally.

It is also possible to lint the files locally:

```bash
Build/Scripts/runTests.sh -s lintScss
Build/Scripts/runTests.sh -s lintTypescript
```

Remember to commit the compiled files alongside any patches, they are part
of the monorepo.