As per this HN comment: https://news.ycombinator.com/item?id=40861716

"I installed it into my jupyter env and it runs fine on port 8889, but the default port 8888, it just sits waiting on the AI to generate a response."

My first thought is that there might be some firewall/routing config that is blocking the fetch calls to AI endpoints on user's machine. Need to ask for followups.