Xcode 27 has no Simulator.app. Devices boot and run in Device Hub, an app inside Xcode. Here is where it lives, what still works, why some tools stopped finding your Simulator, and what SimBuddy does with it.
Device Hub is an app inside Xcode, at Xcode › Contents › Applications › DeviceHub.app. Xcode 26 and earlier keep Simulator.app in Xcode › Contents › Developer › Applications instead.
Open it from Terminal with its full path:
$ open -a /Applications/Xcode.app/Contents/Applications/DeviceHub.app
xcrun simctl still lists, boots, installs, launches, screenshots and records devices: it talks to CoreSimulator, not to the app that shows them.
What stops is anything that looks for Simulator.app: open -a Simulator, a script that finds the app by its path or bundle, or a tool that waits for its window. On Xcode 27 there is no such app, so they can report that no Simulator is running while Device Hub shows one.
xcrun simctl boot, then open Device Hub to see it$ xcrun simctl list devices bootedOpen a device in Device Hub and SimBuddy’s panel appears beside its window and follows it as you move it. ⌘0 shows or hides it. On Xcode 26, the same panel docks on the standalone Simulator.
Everything in the panel
The simbuddy command finds booted devices whichever app shows them, so it answers the same on Xcode 26 and 27.
simbuddy status lists the Simulators that are runningsimbuddy doctor checks Xcode, the Simulator and the bridge, and says what to fix$ simbuddy status$ simbuddy doctorXcode 27 replaces Simulator.app with Device Hub, an app inside Xcode at Xcode › Contents › Applications › DeviceHub.app. Devices boot and run there.
Tools that look for Simulator.app by name, path or window find nothing on Xcode 27, because the devices are shown by Device Hub. xcrun simctl still lists and controls them.
Yes. SimBuddy works with Xcode 27’s Device Hub and with the standalone Simulator on Xcode 26: its panel docks beside the device’s window and follows it.