SimulatorTrampoline – Everything you need to know

Are you an Apple developer and is looking for information about SimulatorTrampoline or SimulatorTrampoline.xpc? Is it asking for permission to access microphone, camera or file system? This short article is going to explain what SimulatorTrampoline is and whether they may affect your system.

What is SimulatorTrampoline?

First and foremost, SimulatorTrampoline is a part of Xcode, so it’s safe and you don’t have to worry a bit about it.

SimulatorTrampoline is actually a proxy that takes responsibility for all processes inside the simulator. It doesn’t know why simulator processes want access so it can’t provide a reason.

If it didn’t exist you’d get prompted many more times. For some specific type of resources such as microphone, the system will keep asking you for permission, you would get both a macOS prompt and an iOS prompt inside the simulator.

From Xcode 11 Release Notes :

When building for the first time users may get a popup stating that SimulatorTrampoline would like access to Desktop Files because ibtool running in simulator needs access to these files to compile storyboards. (51114450)Code language: JavaScript (javascript)

Does SimulatorTrampoline.xpc affects my system or my application.

The prompt “SimulatorTrampoline.xpc would like to access your microphone” (or your files, camera, etc) can pop up even if Xcode is not running.

In case you got the message above, all you need to do is clicking OK and forget about it, SimulatorTrampoline belongs to Xcode itself. It won’t affect either your system or your application.

If it keep asking for the microphone access, you can try changing the Hardware Audio Input to Internal Microphone. What I believe happen is that when you give access it changes the audio input to your headphones or MacBook.

changing the Hardware Audio Input to Internal Microphone

Alternatively, users have reported that disabling microphone access for Xcode altogether makes the SimulatorTrampoline pop up disappear. You can try going to Security & Privacy > Microphone and switch the settings off if your app doesn’t need to use microphone at all.

Add permission to SimulatorTrampoline to access specific folder

If you accidentally denied SimulatorTrampoline to directories, you can explicitly set the permission back by following the instructions below.

  1. Find SimulatorTrampoline.xpc in Finder. A quick way to do this is to open Finder and type SimulatorTrampoline.xpc into the search bar.
  2. Open Security & Privacy > Privacy > Full Disk Access.
  3. Unlock to make changes.
  4. Drop the SimulatorTrampoline.xpc to apps area (it will be invisible). Quit SimulatorTrampoline.xpc if needed.
  5. Now all permissions are set. You can try to use simulator again.

We hope that the information above helps clarify a bit about SimulatorTrampoline. If you have anything to add to the article, feel free to comment below and we would include in as soon as possible.

2 thoughts on “SimulatorTrampoline – Everything you need to know”

  1. Isn’t the spelling “Xcode” (only the first letter capitalized)?

    • Thanks for the correction. We’ve updated the post accordingly.


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