Run a headless Mac mini and see its windows

Your Mac mini is humming on a shelf in another room. You are at your MacBook, trying to open Xcode on the mini, but there is no monitor attached and no useful display waiting for a connection. It works today, perhaps, yet sleep, a power cut, or the next FileVault login screen could leave you walking back with a keyboard and display.

Run Beam on both Macs when you want to beam one Mac mini app window onto your MacBook as a normal window with its own Dock icon and place in ⌘ Tab. Beam shares one window at a time, or a whole display when you pick one.

You can also use macOS Screen Sharing when you want to see and control the mini’s entire desktop. The reliable setup also covers permissions, networking, sleep, power recovery, and the first reboot. We will take each in that order.

Use Beam for a window and Screen Sharing for the desktop

Use Beam on both Macs for one app window or a whole display. You can also use Apple’s built-in Screen Sharing for the mini’s complete desktop.

Choosing a window gives the selected app a place among your local work. Choosing a whole display, whether in Beam or Screen Sharing, gives you a view of a remote display and everything arranged on it.

Beam puts a window from one Mac onto another: the window itself, on your desktop, at its own size, with its own Dock icon and a place in ⌘ Tab. A beamed window is a live view of the window you chose.

It is not a cropped desktop. Your Mac mini can live on a shelf while one of its windows lives beside Safari. That is the idea behind a window, not a screen.

A headless Mac gets a virtual display from Beam at Retina density. A virtual display is a display macOS can draw onto even though no physical panel is connected. The picture is streamed at your display’s exact resolution, so text stays crisp.

This setup needs no HDMI dummy plug. Beam is $49 once, for every Mac you use, no subscription. Made by Noats, Inc. Requires macOS Sonoma or later, on both Macs.

Pair the Macs before the monitor goes away

Before the mini loses its monitor, install and open Beam on both Macs. macOS asks the Mac doing the sharing for Screen Recording and Accessibility, and for the clipboard and the local network when those are used. Grant those permissions while you can still work at the mini. Beam also ships a command line with a doctor that checks permissions and the network on that Mac.

On the same network, Beam discovers other Macs running Beam locally, without asking anything outside the network. Pair them once and the connection is encrypted and pinned to those two machines. Open the picker on your MacBook and choose the mini, then choose the app window you need. Password managers are kept out of the picker by default.

Drag a corner of a beamed window and the real window resizes over there. Type into it and the keystrokes land in the app, shortcuts included.

Toggle the speaker and that app’s audio plays on this Mac. Clipboard content can cross when clipboard sync is on. While you work in a beamed window, nothing moves on the other Mac’s screen.

For the full workspace, pick a whole display in Beam, or enable Screen Sharing on the mini and allow only the intended user. Open the Screen Sharing app on the MacBook, connect to the mini, and choose Standard or High Performance mode. On two supported Apple silicon Macs running Sonoma or later, High Performance mode can make one or two virtual displays without a physical monitor.

Make the empty-room connection survive a restart

Both Macs run Beam. They talk directly over the local network, or over your Tailscale tailnet when apart.

Beam has no account or relay service of its own. A tailnet is the private network Tailscale creates between your devices. Install Tailscale on both Macs and sign them into the same tailnet before you leave the mini behind.

Beam adds no relay of its own. Tailscale tries a direct peer-to-peer connection first, but it may fall back to a peer relay or DERP relay when a direct path is unavailable. That networking layer is separate from Beam’s no-account design. We explain the local path in Nothing goes through a server.

Remote viewing is only half of unattended operation. In the mini’s Energy settings, prevent automatic sleep when the display is off, enable waking for network access where useful, and turn on automatic startup after a power failure. Apple lists those controls for Mac desktops. We set these before the mini moves to its shelf, because a sleeping or powered-off Mac cannot present the window you came for.

Choose the reboot behavior deliberately. Apple states that FileVault makes automatic login unavailable.

Keeping disk encryption may mean physical intervention after a restart. Automatic login avoids that stop on a physically secured mini, but anyone with physical access can restart the Mac and enter that account. Your security and unattended-access needs decide which path fits.

A dummy plug is therefore not the default purchase. Beam supplies its Retina-density virtual display, and Apple’s supported High Performance Screen Sharing can also create virtual displays on qualifying Macs. Once the connection works, restart the Mac mini and check from the MacBook whether Beam becomes available for reconnection. That test shows whether its startup behavior, sleep, power-recovery, and FileVault choices match how unattended it needs to be.