I am wondering if itch.io allows us to use third party programs to help us create content posts. I am planning to make a program that will automatically host jams weekly. I am not sure if itch.io allows us to do that. I have read through the itch.io terms of services and so far I have never encountered a rule saying "all content posts should be created manually without any interruption of third party programs". I want to double confirm here so that I won't get sued or something.

As far as I’m aware, they can’t sue if it’s not in the Terms of Service. But if you’re that paranoid you shouldn’t be asking Itch themselves anyway ;).

It’s not a matter of getting sued, it’s a matter of getting banned. If we feel like the content you are creating is spam then we will ask you to stop or disable your accounts. As long as you’re doing something within reason, it doesn’t matter if the content of your page is created by you or a computer.

For example, if you’re trying to create 100 jam pages at once, then that’s probably not a good idea. Things like trying to create a daily jam for every day I would likely consider spam.