This script was originally made to cache API requests to PokéAPI, to strain their servers just a tiny bit less.
There are 2 constants in the index.rb file, POKE_API_URL and LOCAL_API_URL.
Make sure to change the LOCAL_API_URL to the port you're using, in theory you could change the POKE_API_URL to whatever URL you want and it'll cache those requests in memory.
Start by installing the gems
bundle install
You can then run the script
ruby index.rb
Now that you're done, you can make API calls to your LOCAL_API_URL constant.
This will now serve the JSON, instead of always fetching directly from the POKE_API_URL.