These are drop-in libraries for adding an API endpoint to a Flamework project.
It includes libraries and webpages for dispatching API requests and responses as well as creating and managing API keys.
There is also support for authenticated API methods using cookies (not really useful for third-party things) and OAuth2 access tokens (which means you've got a site that uses SSL).
You can either install all of the files manually or you can the bin/setup.sh
script which will install most of the relevant bits automatically and make a
note of the stuff you'll see need to do yourself.