Yeah, I checked that in intentionally. I've started checking in plans under `plans/` so that people can see the plan during code review, and also so I can refer to it when I prompt agents about things related to the plan. My usual process for using AI is I first tell it what I want and have it write out a plan. I then review the plan, make comments, and go back and forth until I like it. Then I ask it to implement. I find this makes the final code output much easier to review -- it's almost always very close to what I want on the first try.
The project is indeed in early stages. That's mentioned in the readme as well.
The reason I had to tell the agent this explicitly is because Fable's original plan called for an overly careful process involving a 2-3 day "spike" to test and derisk. It also wanted to write an elaborate test harness that would run every message through both the old and new paths and compare the results to ensure feature parity. It was way too cautious. I knew that the conversion would actually work fine. And, in fact, it did: the conversion actually fixed more bugs than it introduced.
I tweeted about this at the time: https://x.com/KentonVarda/status/2084293600142135365