Launching today
Reclaim
Two machines, one monitor, one keystroke to take it back
2 followers
Two machines, one monitor, one keystroke to take it back
2 followers
Two computers, one monitor. Reclaim runs on your Mac and switches the monitor between the two with one shortcut. Press it on your Mac's keyboard to send the screen to the other computer. Press it again to bring it back. You never have to see the Mac's screen to do it, and you never have to touch the monitor's buttons. Nothing is installed on the other computer. Nothing to set up either: Reclaim reads both inputs from the monitor itself. No permissions, no network, free.
At my office I have two machines on one monitor: my own Mac mini, and a locked work PC I have no admin rights on and cannot install anything on. Switching between them meant reaching around the back of the monitor and poking at the OSD buttons every time, which is as slow as it sounds.
Then I noticed the fight was rigged. The monitor switches input automatically to whichever machine has just started sending a picture. The PC sleeps, so the moment I nudged its mouse it woke up, sent a fresh signal, and took the screen. My Mac never sleeps. It is always awake and always sending, so it never produced that event and never had a way to answer. The PC could steal the monitor and the Mac could not take it back.
I went looking for the app that fixes that. m1ddc is a command line binary, which is not something you press while looking at a different computer. BetterDisplay and DisplayBuddy are much larger apps that do input switching among many other things. None of them were built around the one moment I actually cared about: I am sitting in front of the PC, my Mac's screen is nowhere to be seen, and I want the monitor without touching it.
So I built the rescue. What I use every day turned out to be the swap. One key sends the screen across to the PC, the same key brings it home, and I have not touched the monitor's buttons since. That is the real product: not an emergency button, but the switch the monitor should have shipped with. Reclaim asks the monitor which machine it is showing and sends it the other way, so a single shortcut covers both directions and you never have to think about which side you are on.
It works from either machine because a keyboard shortcut does not need a screen, which is the whole trick: the moment you want to switch is exactly the moment you cannot click anything on the Mac. Your Mac speaks to the monitor over the video cable itself, and nothing is installed on the PC, which matters when the PC is not yours.
The part I got wrong first is my favourite part. Monitors name their inputs with numbers that differ by brand, and my first build shipped with a sensible default. On my monitor that default was the PC, so pressing the shortcut cheerfully handed the screen to the other machine. Exactly backwards. Now Reclaim never guesses: it asks the monitor which input it is on, keeps the answer, learns the other machine's the first time it sees it, and warns you if the value it is about to send would move the screen the wrong way.
The other lesson: the system call that sends the command reports success even when the monitor has no such feature at all. I proved that against a MacBook's built-in screen, which cannot possibly answer. So Reclaim judges every attempt by what the monitor actually replies, and says plainly when it got nothing. And for monitors that answer but refuse to change input while showing something else, there is a second route that asks the monitor for nothing: it drops your Mac's picture for two seconds and brings it back, so the Mac arrives looking like a machine that just woke. That is the same event the monitor already reacts to when the PC wakes and takes the screen.
It needs no permissions, sends nothing anywhere, and is free. Apple silicon only, because the way it reaches a monitor does not exist on Intel Macs, and it says so rather than looking broken.
Every app I build starts the same way. I went looking for it, and it wasn't there. Either nothing did the job at all, or the apps that existed did most of it and stopped just short of the part I actually needed. That gap is the whole product.
If you keep two machines on one monitor, I would genuinely like to know whether yours plays along. Reclaim has a check built in that answers it in about a minute, including the harder question of whether the monitor still listens while it is showing the other machine. Some do not, and no software can fix that. I would rather it told you in a minute than left you guessing.