This is a Dart framework/builder for scripting Battlefield Portal without the official Blockly Editor from EA.
Have a look at the example to get an idea of how the development experience will be.
You need the Dart SDK for this framework. Download and install it from https://www.dartlang.org/tools/sdk
Create a folder for your project and create an empty pubspec.yaml.
Open a terminal in the folder you've just created and type in dart pub add bfportalbuilder.