Hi HN, I built BotParty.

It's a native macOS/iOS chat client for openrouter, built around Swift's DocumentGroup.

Each conversation is a regular file on disk — you can save them in folders, sync them with iCloud, email it. I made it because I got sick of the claude desktop app changing it’s system prompts on me constantly. I also wanted to be able to own all my own chats, and archive them locally. You can branch conversations by using ‘duplicate’ in the finder - which is something that i’ve found missing from all the other desktop chat apps.

A few things that fell out of the document model: - Conversations are diffable, so git history works - You can have many open at once in tabs/windows - Share Sheet and Spotlight search work - Nothing is locked into my app

I used openrouter so you can use claude/chatgpt/etc.

Thanks for reading this far. Feedback very welcome, especially on the file format.