I put AI in my email client and then refused to resell it

Every app in my category now has an AI subscription attached. I built the same features compose, summarise, refine, translate and then took the resale out.

 On the Mac App Store build there is no server of mine in the path. You paste in your own OpenAI or Anthropic key and the app talks to the provider directly. I don't meter it, mark it up, or see the text.

The reason is that the pitch of the whole product is that your mail stays on your disk and nothing routes through a machine I run. A relay would have made that false in the one place the content is most sensitive  the body of themessage. I'd have needed a paragraph in the privacy policy explaining the exception, and that paragraph is the product arguing with itself.

 What I keep hearing is that this leaves money on the table usage-based AI is where the margin is. Maybe. But the buyers I have are the ones with a compliance officer, and "no third party in the path" closes them faster than a feature does.

The part I'm actually proud of isn't AI at all. Translating an attachment properly means translating the file, not the preview. The viewer already renders .docx through mammoth and .xlsx through SheetJS, and translating that HTML would have been an afternoon's work — but then the download would be a different document: no styles, no headers, no page setup. So it rewrites the file. A .docx is XML in a zip; the entries it doesn't touch get copied across still compressed, and the two or three it does rewrite go through the platform's own CompressionStream. No zip library, works offline, works inside the App Store sandbox. Preview and download are the same bytes, and "Show Original" is a re-render of the untouched ones. PDFs keep their page and wear the translation over it; scanned ones go through macOS's own OCR.

Has anyone else taken the resale out and regretted it? If you're charging for AI on top of a one-time purchase, is it actually converting?