I’ve been building a small Mac app called Blueby. It does one thing: it listens for Bluetooth devices connecting, disconnecting, arriving and leaving, and runs the actions you tell it to.
When my Apple Watch leaves the room, my Mac locks itself. When my AirPods connect, Music starts at 40% volume. When my keyboard wakes up after the weekend, a Shortcut opens the project I was working on Friday.
None of these are impressive features individually – locking a Mac, setting a volume, launching an app are all one-line scripts. What’s strange is that, in 2026, the Mac still doesn’t ship with anything that does this kind of thing for you.
So I built it.
The hole in the Mac
My Mac knows when my AirPods are connected. It uses that information to do exactly one thing: route audio through them.
It also knows when my Apple Watch is in range. It uses that information to do exactly one thing: skip the password prompt when I open the lid.
That’s it. Two devices, two outcomes, both hardcoded by Apple, both useful, both stopping a centimeter short of being *automation*.
Meanwhile I have a perfectly good rule in my head — *if I’m not at my desk, lock the screen* — that the Mac has every signal it needs to execute, and yet I still have to remember to hit Control-Command-Q before I get up to refill my cup. Half the time I forget.
That gap is where Blueby sits. Bluetooth presence in. Mac actions out. One sentence per rule.
What’s in the box
Blueby is a menu bar app. No dock icon, no main window – just a small icon up top that pulses for a second when one of your rules fires.
You add a device. Blueby calibrates “near” automatically. Then you write rules in a sentence-style editor:
> When [Apple Watch ▾] [moves away ▾] for at least [10 seconds ▾]
> Then [Lock screen ▾]
Triggers: connected, disconnected, moves away, moves close. Actions: lock, sleep, launch app, set volume, run a Shortcut, run a shell script, send a webhook, run AppleScript. That’s the product. There’s no AI, no cloud, no subscription. Your activity log lives in a JSON file on your machine and never leaves it.
Download the app at https://blueby.app