I want to create a command "!heigth".
If a user typed it for the first time, it will give them a random number between 50 and 250, centimeters.
If that user typed it again, they will get that exact first height forever
At the moment Nightbot doesn't have a mechanism to store this information, so it isn't possible to accomplish this at the moment. It is possible to leverage a custom API to accomplish this though, and you can leverage the url fetch variable alongside that: <https://docs.nightbot.tv/variables/urlfetch>