Show HN: Multitui – sandbox claude, codex, or any TUI with custom macOS apps

I made Multitui to control the sandbox of coding agents easily without changing my dev environment (no special container or VM). There's no configuration required in your local dev environment... just launch ClaudeCode.app instead of claude in your general terminal. Containers and VMs can be useful, but I always have a bunch of projects going and those solutions feel heavy.

Multitui creates single-purpose macOS apps for any terminal app, with optional sandbox. It uses the built-in macOS sandbox-exec along with log monitoring to give you an easy UI to manage rules, see what's being blocked, and add rules as you observe files that need to be allowed.

The apps you create are highly customizable and provide many native macOS integrations (document-based app model, Finder integration, global shortcut, etc). It's built with Swift, so it's fast and lightweight.

I also like the idea of TUIs being first-class apps, like what Omarchy did on linux. It helps me context-switch better than cycling through ten similar-looking tabs in Ghostty.

It's free in beta and free for personal use forever.

https://multitui.com

Does this seem useful? Does it need network sandboxing too?

-David