Umbra is a small, local-first toolbox for the tools developers reach for every day — built to run entirely on your machine, with nothing else assumed.

It's fast because there's no browser bundled inside it. A native Rust core drives the app directly — unlike an Electron-style app, it doesn't ship its own copy of Chromium — so it opens and responds like a small program should.

The Mac build is checked by Apple before you ever see it. Signed with a Developer ID certificate and notarized by Apple.

Nothing you use it for is sent anywhere. The app makes no network calls except one, disclosed — the check for a new version — and you can confirm it yourself with a network monitor while it runs.

Windows and Linux are labeled honestly, not oversold. They work, but they're tested less than the macOS build, and that's said plainly rather than implied otherwise.