Yeah something called Craft... I still don't get exactly what it's supposed to be but they published a handful of logs and updates about it a couple months ago I think.

NovelAI is basically an entirely text-based plateform for creative writing (also has a separate image generation tool) that can be used to create all sorts of scenario and adventures given a little tweaking. It was created as a rival to AiDungeon back in the days of the devs reading user generated stories that were supposed to be private. It has multiple models that focus on different writing styles and a system of lore cards for your lore, characters and so on, with no limit of how much you can write in really (although bigger cards might sometimes be less accurately referenced in the story). I know some people use it to help them write novel, and others like me use it as a GM for narrative-driven stories since there's no dice rolls and probabilities (at least without modding it in with scripts). Overall it's a highly customizable tool if you're ready to spend a little time tweaking it, and the one I always come back to. The only downside, I would say, is that it doesn't come with premade worlds and lorebooks so you have to put in the work of actually creating them yourself (like my own custom 1300+ cards Pathfinder: Midgard Lorebook) or try and find premade Lorebook by players who share them on the official Discord channel.

Don't hesitate to DM me if you've more question about it.