Hi, I'm trying to create a launch daemon that uses XPC to receive requests from an unprivileged app. Ultimately both components will be written in Go. For now I'm trying to write a PoC in Objective-C to make sure I get everything right, so I'm compiling / signing from the CLI, and writing plist files by hand -- I'm not using XCode. My current daemon code is pretty much the same as the boilerplate code that XCode generates when creating a new 'XPC Service': #import <stdio.h> #include <xpc/xpc.h> int main(int argc, char *argv[]) { xpc_rich_error_t error; dispatch_queue_t queue = dispatch_queue_create("com.foobar.daemon", DISPATCH_QUEUE_SERIAL); xpc_listener_t listener = xpc_listener_create( "com.foobar.daemon", queue, XPC_LISTENER_CREATE_NONE, ^(xpc_session_t _Nonnull peer) { xpc_session_set_incoming_message_handler(peer, ^(xpc_object_t _Nonnull message) { int64_t firstNumber = xpc_dictionary_get_int64(message, "firstNumber"); int64_t secondNumber = xpc_dictionary_get_int64(message, "secondNumber"); // Create a reply and send it back to the client. xpc_object_t reply = xpc_dictionary_create_reply(message); xpc_dictionary_set_int64(reply, "result", firstNumber + secondNumber); xpc_rich_error_t replyError = xpc_session_send_message(peer, reply); if (replyError) { printf("Reply failed, error: %s", xpc_rich_error_copy_description(replyError)); } }); }, &error); if (error != NULL) { printf("ERROR: %s\n", xpc_rich_error_copy_description(error)); exit(1); } printf("Created listener: %s", xpc_listener_copy_description(listener)); // Resuming the serviceListener starts this service. This method does not return. dispatch_main(); return 0; } I'm compiling, signing and installing my daemon with the following commands: build_foobar() { clang -Wall -x objective-c -o com.foobar.daemon poc/main.m codesign --force --verify --verbose --options=runtime \ --identifier="com.foobar.daemon" \ --sign="Mac Developer: Albin Kerouanton (XYZ)" \ --entitlements=poc/entitlements.plist \ com.foobar.daemon } install_foobar() { sudo cp com.foobar.daemon /Library/PrivilegedHelperTools/com.foobar.daemon sudo cp poc/com.foobar.daemon.plist /Library/LaunchDaemons/com.foobar.daemon.plist sudo launchctl bootout system/com.foobar.daemon || true sudo launchctl bootstrap system /Library/LaunchDaemons/com.foobar.daemon.plist } Here's the content of my entitlements.plist file: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>com.apple.application-identifier</key> <string>ABCD.com.foobar.daemon</string> </dict> </plist> And finally, here's my launchd plist file: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>Label</key> <string>com.foobar.daemon</string> <key>Program</key> <string>/Library/PrivilegedHelperTools/com.foobar.daemon</string> <key>ProgramArguments</key> <array> <string>/Library/PrivilegedHelperTools/com.foobar.daemon</string> </array> <key>RunAtLoad</key> <false/> <key>StandardOutPath</key> <string>/tmp/com.foobar.daemon.out.log</string> <key>StandardErrorPath</key> <string>/tmp/com.foobar.daemon.err.log</string> <key>Debug</key> <true/> </dict> </plist> Whenever I start my service using sudo launchctl start com.foobar.daemon, it exits with the following error message: ERROR: Unable to activate listener: failed at listener activation with error 1 - Operation not permitted System logs don't show anything interesting -- they're just repeating the same error message. I tried to add / remove some properties from both the entitlement and the launchd plist file but to no avail. Any idea what's going wrong?