Sass4fUser Guide

Sass4f is a support library that aids Alien-Factory in the development of other libraries, frameworks and applications. Though you are welcome to use it, you may find features are missing and the documentation incomplete.


Sass4f is a wrapper around libSass 3.2.5 - libSass 3.2.5 - the compiler for Sass and Scss files.

Sass4f is a simple command line utility program for compiling .scss files into .css files. It was created for compiling Twitter Bootstrap 4 templates and has been successfully tested with Bootstrap v4.0.0-beta.2.

Sass4f is a happy alternative to installing Sass, Node.js, Grunt, and half the Internet just to compile a couple of text files!

Quick start example:

C:\> fan afSass4j -x C:\projects\website.scss C:\projects\website.css

Quick Start

Once installed, run Sass4f from the command line:

C:\> fan afSass4j [-x] [-m] <sassIn> <cssOut>

Where sassIn and cssOut are files. OS dependent and / or URI notation may be used. Example:

C:\> fan afSass4j -x C:\projects\website.scss C:\projects\website.css

C:\> fan afSass4j -x file:/C:/projects/website.scss file:/C:/projects/website.css

-x compresses the CSS output, -m generates a source map, and -w continuously watches for file updates.

Note that cssOut may also be a directory, for example:

C:\> fan afSass4j -x -m -w scss\website.scss css\

will generate css\website.css and re-compile it should any file in the scss/ directory be updated.


Sass4f is bundled with pre-compiled native binaries for the following platforms:

  • linux-x86
  • linux-x86_64
  • macosx-x86_64
  • win32-x86
  • win32-x86_64

When Sass4f is first run, the appropriate binary is copied to %FAN_HOME%/bin/ so it may be loaded by Java.


Sass4f is designed to be used a standalone application and as such, comes bundled with the following jars:

  • jna-4.2.1.jar
  • jna-platform-4.2.1.jar
  • jnaerator-runtime-0.11.jar


Sass4f uses JNAerator to communicate with libSass - an idea taken from sass-java.