How does the bot reserve hotel rooms? Through an API or does your bot interact with a website. How do you validate that your code is still able to reserve an ho

How does the bot reserve hotel rooms? Through an API or does your bot interact with a website. How do you validate that your code is still able to reserve an hotel room lets say 3 years after writing it; I can imagine that changing systems will break you code. Not trying to be a smart ass, just interested :)