Show HN: Vim-like undo history for OpenAI API prompts

Having been saved by Vim's infinite, persistent, and branched undo for years, I was disappointed that OpenAI's playground has no concept of history whatsoever.

Was wasting too much time getting API calls just right, so I built this on the side. The core feature is the branched undo history + diffing between any two historical nodes.

I hope it may be useful to someone else, but I would greatly appreciate any feedback - including harsh, but actionable feedback.

Unfortunately I do have to require a login to prevent abuse since this is tied to my personal API key.