My mistake. Well over 20.
https://www.google.com/search?q=site%3Agithub.com+keep+mac+o...
First one I used was around 9 years ago. Nearly melted my backpack with the hot Intel CPU!
If you don't want to install anything, you can disable sleep with the built in tools: sudo pmset -a disablesleep 1
Yeah, most of these repositories contain more files than caffeinate+ has lines of code.
The API call that 'sudo pmset -a disablesleep 1' does is literally the first thing caffeine+ does. But is only part of the full solution: As soon as the lid closes the command is automatically reverted so you can't forget to do it yourself. Also if you kill caffeinate+, the MacBook is put to sleep when the lid is still closed.