My initial design used one million tokens but I quickly discovered that tokens are not made equal which made it very difficult to reason about. Eventually, I settled on one million characters.
The chat has a few different capabilities, for example, you can ask it to navigate to a position for you (e.g: "jump to the final character") and it can search within the context. I have more things to add, like the ability to play music from the songs included in its context.
Other visitor's cursors can be seen in real-time when they are adding to the chat's brain.
Despite the fact that this is an AI project, I built it by hand. I tried out Claude Code and Codex but neither produced code I was happy with.
The current model is openai/gpt-4.1-nano. I figure, people paying to add characters will subsidise chatter's free access to the model.