API Core is now its own plugin, which provides the ReactionAPICore class. You can use it to build a NodeJS microservice that’s compatible with the Open Commerce platform, or you can build your main Open Commerce API on it if you don't want to fork the /reaction project.

/reaction is now a shell project that imports all of the required NPM packages.

API Core now gives developers more flexibility—part of a broader move away from forking being the primary way of working with the Open Commerce codebase.