Is there anything built in gradle to cache a variable used during a task run for like an hour? Or do I need to do it manually? Basically, I have a task that tries to find the IP address of a specific device using a ton of different methods. If it finds one, I want every invokation done within the next hour to add that address into the lookup list, since some of the lookup methods are slow.

I think what you are after is https://github.com/gradle/gradle/issues/31908, so no. But you can probably do it by having a task that has the current date and hour as input (additionally to the other inputs) and a file with the IP as output. Then you reuse the result for up to an hour.