monthlet

monthlet is an AI-native note app. Instead of formatting notes by hand, you dump raw thoughts — bullets, fragments, no structure needed — and tell it in plain language what you want. The AI writes the note and automatically decides the layout: banners, columns, tabs, real spreadsheets, live charts, full-note themes. To revise, you just ask, and only that part updates. Every note is a plain HTML file stored locally on your disk — no cloud service, no lock-in, readable in any browser for years to come. External agents such as Claude Code can read and write those notes through the app itself, so the change history and the open tab stay in step.

The app is free and complete with your own AI key (Claude, OpenAI, or Gemini). Available on macOS (Apple Silicon, M1 or later); Windows coming soon.