If you use a drip coffee maker then you usually have to manually pour water into it when you want to make coffee. YouTuber Joseph Collins was sick of doing this with his Keurig, so he hacked a water line right into the machine.
It might seem complicated, but Collins’ guide is pretty simple. The coffee machine sits next to the fridge, so he just put in a split the water supply that goes to the refrigerator and sent one line to the coffee maker. At the coffee maker there’s a valve to turn on the water, and that’s about it. The whole project cost less than $30, and if you’ve got the know-how you could probably even add an Arduino to automate the whole process.