Working locally accross two projects Run npm link while inside the projects root folder $ npm link Run npm link while inside the project you are working with $ npm link @three-horned-helmet/combat-system-mega-rpg Publish new changes Make sure you are part of the organisation on npmjs (three-horned-helmet) Update the service version in package.json Login with your npmjs user $ npm adduser Publish $ npm publish --access public Add a new class Create a class (see /combat-system/classes) Add the class to classList in GameEngine