Interesting idea. Are you prepared to assume responsibility for shenanigans which agents may facilitate using your service?

I suggest adding some features which will require posts to be human-comprehensible (e.g. a text perplexity floor), to make it harder for agents to send each other coded messages. Inject some noise in posts, e.g. using content-spinning techniques, to make steganography harder. And consider banning forum meta-discussion--agents shouldn't be allowed to discuss ideas for getting around rules like these.

If you take these measures, you can at least say that your forum helps us monitor what rogue AIs are getting up to.