XPC is the preferred inter-process communication (IPC) mechanism on Apple platforms. XPC has three APIs: The high-level NSXPCConnection API, for Objective-C and Swift The low-level Swift API, introduced with macOS 14 The low-level C API, which, while callable from all languages, works best with C-based languages General: DevForums tag: XPC Creating XPC services documentation NSXPCConnection class documentation Low-level API documentation XPC has extensive man pages — For the low-level API, start with the xpc man page; this is the original source for the XPC C API documentation and still contains titbits that you can’t find elsewhere. Also read the xpcservice.plist man page, which documents the property list format used by XPC services. Daemons and Services Programming Guide archived documentation WWDC 2012 Session 241 Cocoa Interprocess Communication with XPC — This is no longer available from the Apple Developer website )-: Technote 2083 Daemons and Agents — It hasn’t been updated in… well… decades, but it’s still remarkably relevant. TN3113 Testing and Debugging XPC Code With an Anonymous Listener XPC and App-to-App Communication DevForums post Validating Signature Of XPC Process DevForums post Related tags include: Inter-process communication, for other IPC mechanisms Service Management, for installing and uninstalling Service Management login items, launchd agents, and launchd daemons Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

Hello, I'm developing a Mac application that uses a network extension. I'm trying to implement XPC to pass data between my main app and system extension and I'm using the SimpleFirewall demo app as a guide to do this. One thing I can't understand is how the ViewController in the SimpleFirewall main app has access to the class IPCConnection in the SimpleFirewallExtension without it being public and without SimpleFirewallExtension being imported in ViewController.

hello everyone On iOS18.0+, app crashed at BSXPCCnx:com.apple.backboard.hid-services.xpc (BSCnx:client:BKHIDEventDeliveryObserver) when app enter background sometimes crash stacktrace: Crashed: BSXPCCnx:com.apple.backboard.hid-services.xpc (BSCnx:client:BKHIDEventDeliveryObserver) 0 libsystem_pthread.dylib 0x4078 pthread_mutex_lock + 12 1 ilink_live 0xbd884 (缺少 UUID 973fe6c5058c35bda98679b0c8aa0129) 2 ilink_live 0xb75fc (缺少 UUID 973fe6c5058c35bda98679b0c8aa0129) 3 libsystem_c.dylib 0x23190 __cxa_finalize_ranges + 492 4 libsystem_c.dylib 0x22f8c exit + 32 5 BackBoardServices 0x31b78 -[BKSHIDEventObserver init] + 98 6 BoardServices 0x1dc78 __31-[BSServiceConnection activate]_block_invoke.182 + 128 7 BoardServices 0x1beb4 __61-[BSXPCServiceConnectionEventHandler _connectionInvalidated:]_block_invoke + 196 8 BoardServices 0x4a58 BSXPCServiceConnectionExecuteCallOut + 240 9 BoardServices 0x1d6e8 -[BSXPCServiceConnectionEventHandler _connectionInvalidated:] + 180 10 libdispatch.dylib 0x2248 _dispatch_call_block_and_release + 32 11 libdispatch.dylib 0x3fa8 _dispatch_client_callout + 20 12 libdispatch.dylib 0xb5cc _dispatch_lane_serial_drain + 768 13 libdispatch.dylib 0xc158 _dispatch_lane_invoke + 432 14 libdispatch.dylib 0xb42c _dispatch_lane_serial_drain + 352 15 libdispatch.dylib 0xc158 _dispatch_lane_invoke + 432 16 libdispatch.dylib 0x1738c _dispatch_root_queue_drain_deferred_wlh + 288 17 libdispatch.dylib 0x16bd8 _dispatch_workloop_worker_thread + 540 18 libsystem_pthread.dylib 0x3680 _pthread_wqthread + 288 19 libsystem_pthread.dylib 0x1474 start_wqthread + 8 when crash happened ,most of time app recieved CBManagerStateResetting and CBManagerStateUnsupported event i would appreciate any insights or recommendations on how to resolve this issue thx crash_stacktrace.txt

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?

I'm attempting to install a NetworkExtension as a system extension, using the OSSystemExtensionManager.shared.submitRequest(request) API call. I can see from console logs and systemextensionsctl that my system extension is getting installed, but the OSSystemExtensionRequestDelegate I attach to the request never gets a callback. In the console logs I see: com.apple.sx default 14:13:25.811827+0400 sysextd activateDecision found entry to replace: com.coder.Coder-Desktop.VPN, BundleVersion(CFBundleShortVersionString: "1.0", CFBundleVersion: "1") default 14:13:25.811888+0400 sysextd initial activation decision: requestAppReplaceAction(<sysextd.Extension: 0xa94030100>) com.apple.sx default 14:13:25.811928+0400 sysextd notifying client of activation conflict com.apple.xpc default 14:13:25.812156+0400 Coder Desktop [0x154f2d5b0] invalidated because the current process cancelled the connection by calling xpc_connection_cancel() com.apple.xpc default 14:13:25.813924+0400 sysextd [0xa941d4280] invalidated because the client process (pid 2599) either cancelled the connection or exited com.apple.sx default 14:13:25.814027+0400 sysextd client connection (pid 2599) invalidated It appears that something within my app process is cancelling the XPC connection to sysextd, but I'm certainly not calling it from within my code. Presumably something within the OSSystemExtension* APIs are cancelling the connection but I don't know why. It seems to be happening very quickly (within a few hundred ms) after sending the request, and before sysextd can reply. What could cause this connection to be canceled?

Hi everyone, I’m encountering a crash in my app and need help understanding what’s causing it and how to resolve it. As stated in the crash report, the issue is caused by exceeding the system-wide per-process port limit. Can you tell me how to locate and identify why this is happening? Below are the full report of the crash log: crash.log Summary of Crash: ------------------------------------- Translated Report (Full Report Below) ------------------------------------- Incident Identifier: B509FF2B-C8D8-4E9F-B664-E24464CFD5F8 CrashReporter Key: b390cfe931a83efde49bd8b523023a275b55ef64 Hardware Model: iPhone14,2 Process: MyApp [22515] Path: /private/var/containers/Bundle/Application/F73212A7-4CB9-485A-A8B7-8114F4E9A9AB/MyApp.app/MyApp Identifier: com.beeasy.app.id.enterprise Version: 3.41.38-ID-MySDKMemory-12261114 (3.41.38-ID-MySDKMemory-12261114) Code Type: ARM-64 (Native) Role: Foreground Parent Process: launchd [1] Coalition: com.beeasy.app.id.enterprise [515] Date/Time: 2024-12-29 01:29:48.3023 +0800 Launch Time: 2024-12-26 16:38:36.7895 +0800 OS Version: iPhone OS 16.6.1 (20G81) Release Type: User Baseband Version: 2.80.01 Report Version: 104 Exception Type: EXC_RESOURCE (SIGKILL) Exception Codes: 0x000000000001c1d6, 0x0000000000000000 Termination Reason: PORT_SPACE 14123288431433990614 (Limit 115158 ports) Exceeded system-wide per-process Port Limit Triggered by Thread: 64 Thread 64 name: AURemoteIO::IOThread Thread 64 Crashed: 0 libsystem_kernel.dylib 0x20ce5eca4 mach_msg2_trap + 8 1 libsystem_kernel.dylib 0x20ce71b74 mach_msg2_internal + 80 2 libsystem_kernel.dylib 0x20ce71e4c mach_msg_overwrite + 540 3 libsystem_kernel.dylib 0x20ce5f1e8 mach_msg + 24 4 libEmbeddedSystemAUs.dylib 0x238bb2148 void* caulk::thread_proxy<std::__1::tuple<caulk::thread::attributes, AURemoteIO::IOThread::IOThread(AURemoteIO&, caulk::thread::attributes const&, caulk::mach::os_workgroup_managed const&)::'lambda'(), std::__1::tuple<>>>(void*) + 556 5 libsystem_pthread.dylib 0x22dcda6b8 _pthread_start + 148 6 libsystem_pthread.dylib 0x22dcd9b88 thread_start + 8

Hello, My team has developed a DNS proxy for macOS. We have this set up with a system extension that interacts with the OS, and an always-running daemon that does all the heavy lifting. Communication between the two is DNS request and response packet traffic. With this architecture what are best practices for how the system extension communicates with a daemon? We tried making the daemon a socket server, but the system extension could not connect to it. We tried using XPC but it did not work and we could not understand the errors that were returned. So what is the best way to do this sort of thing?

Hi, My iphone 12 has been restarting unexpectedly, and often followed by wifi, bluetooth, and airdrop grayed out. I had to force restart/shutdown several times to turn it on again. Found this analytics after crash. Please help if somebody know what this means: ExcUserFault_CategoriesService-2024-12-23-064503.ips

I'm try to monitor all processes by ES client. But I found the process name is different from the Activity Monitor displayed. As shown in the picture below, there are ShareSheetUI(Pages) and ShareSheetUI(Finder) processes in Activity Monitor, but I can only get the same name ShareSheetUI, I thought of many ways to display the name in parentheses, but nothing worked, so there is a way to display the process name like Activity Monitor?

I'm developing a file access control system. In order to protect the file content copied out, I'm finding a way to deny user copy file content to other files. I know there are data transmission between the copied application and pboard service by XPC. But I don't know how to interrupt the data transmission. Or I can do something to stop the copied data send to the Clipboard. So is there any way to prevent the contents of a file being copied?

when app enter background,sometimes crash at BSXPCCnx:com.apple.backboard.hid-services.xpc (BSCnx:client:BKHIDEventDeliveryManager) this is crash stack: 0 libsystem_pthread.dylib 0x3b30 pthread_mutex_lock + 12 1 ilink_live 0xbd884 (缺少 UUID 973fe6c5058c35bda98679b0c8aa0129) 2 ilink_live 0xb75fc (缺少 UUID 973fe6c5058c35bda98679b0c8aa0129) 3 libsystem_c.dylib 0x23d68 __cxa_finalize_ranges + 492 4 libsystem_c.dylib 0x23b64 exit + 32 5 BackBoardServices 0x579ec -[BKSHIDEventDeliveryManager _initForTestingWithService:] + 98 6 BoardServices 0xbae8 __31-[BSServiceConnection activate]_block_invoke.182 + 128 7 BoardServices 0x17620 __61-[BSXPCServiceConnectionEventHandler _connectionInvalidated:]_block_invoke + 196 8 BoardServices 0x8f64 BSXPCServiceConnectionExecuteCallOut + 240 9 BoardServices 0x18e5c -[BSXPCServiceConnectionEventHandler _connectionInvalidated:] + 180 10 libdispatch.dylib 0x2370 _dispatch_call_block_and_release + 32 11 libdispatch.dylib 0x40d0 _dispatch_client_callout + 20 12 libdispatch.dylib 0xb6d8 _dispatch_lane_serial_drain + 744 13 libdispatch.dylib 0xc214 _dispatch_lane_invoke + 432 14 libdispatch.dylib 0x17258 _dispatch_root_queue_drain_deferred_wlh + 288 15 libdispatch.dylib 0x16aa4 _dispatch_workloop_worker_thread + 540 16 libsystem_pthread.dylib 0x4c7c _pthread_wqthread + 288 17 libsystem_pthread.dylib 0x1488 start_wqthread + 8 when crash happened ,most of time app recieved CBManagerStateResetting and CBManagerStateUnsupported event

Hi, For one our requirement sendProviderMessage is been used to send some event/message from app to system extension, In my requirement, responseHandler in system extension would get explicitly called approximately after 1 min due to some async download file task. But observing some strange behavior that responseHandler is getting called implicitly after ~20-30 seconds even before the code hit the place where its called explicitly. And that is the only place I'm calling responseHandler. Can somebody please help about this strange behavior, Is there any implicit timeout interval associated with the responseHandler. Thanks &amp;amp; Regards, Preethi

Hello everyone, We have an iOS XCFramework that we distribute to our clients, and we're exploring ways to enhance its security. Specifically, we’d like to isolate the most sensitive code by running it in a separate process, making it harder to tamper with. During our research, we considered using XPC for iOS but found its functionality to be quite limited. We also explored App Extensions, but unfortunately, they cannot be integrated into an XCFramework. This leads us to the question: Is it possible to spawn a new process to run in parallel with the main one in iOS? If so, could you provide guidance or suggest alternative approaches to achieve this within the constraints of iOS development? Thank you in advance for your insights and advice! Best regards, Stoyan

I'm looking into a newer XPC API available starting with macOS 14. Although it's declared as a low-level API I can't figure it how to specify code signing requirement using XPCListener and XPCSession. How do I connect it with xpc_listener_set_peer_code_signing_requirement and xpc_connection_set_peer_code_signing_requirement which require xpc_listener_t and xpc_connection_t respectively? Foundation XPC is declared as a high-level API and provides easy ways to specify code signing requirements on both ends of xpc. I'm confused with all these XPC APIs and their future: Newer really high-level XPCListener and XPCSession API (in low-level framework???) Low-level xpc_listener_t & xpc_connection_t -like API. Is it being replaced by newer XPCListener and XPCSession? How is it related to High-level Foundation XPC? Are NSXPCListener and NSXPCConnection going to be deprecated and replaced by XPCListener and XPCSession??

We use as content filter in our app to monitor flows, we gather data about the flow and block flows deemed suspicious. Our content filter is activated/deactivated by a UI app but the flows are reported via XPC to a separate daemon process for analysis. As of macOS 15, we are seeing cases where flows are missing or flows are not received at all by the content filter. The behaviour is not consistent, some devices seem to receive flows normally but others don't. It appears Intel devices are much less prone to showing the problem, whereas Arm devices routinely exhibit missing flows. On macOS 14 or earlier, there is no sign of missing flows. Testing on earlier beta versions of macOS 15 did not appear to show the problem, however I can't rule out if issue was present but it wasn't spotted. Experimenting with simple examples of using a content filter (e.g. QNE2FilterMac) does not appear to reproduce the issue. Questions, What has changed between macOS 14 and 15 that could be the cause of the lack of flows? Is our approach to using an app activated content filter reporting to a daemon connected via XPC unsupported?

I was experimenting with Service Management API and Xcode project from https://developer.apple.com/documentation/servicemanagement/updating-your-app-package-installer-to-use-the-new-service-management-api and faced some issues with the API. I replaced agent with XPC service and tried to re-register it. Use case is a new app package installation with a newer service binary. In order to get the running service restarted with the new binary it's required to unregister old version and register new one. Otherwise the old version would be still running after app upgrade. The problem is that register fails with "Operation not permitted" error after running unregister which seems to work fine. Experiments with some delays (500ms) between unregister and register seem to help but it's a not a good solution to work around the problem. I'm using open func unregister() async throws with description: The completion handler will be invoked after the running process has been killed if successful or will be invoked whenever an error occurs. After the completion handler has been invoked it is safe to re-register the service. Sample output with no 500ms sleep between unregister and register calls: /Library/Application\ Support/YourDeveloperName/SMAppServiceSampleCode.app/Contents/MacOS/SMAppServiceSampleCode unregister &amp;&amp; /Library/Application\ Support/YourDeveloperName/SMAppServiceSampleCode.app/Contents/MacOS/SMAppServiceSampleCode register Successfully unregistered LaunchDaemon(com.xpc.example.service.plist) Unable to register LaunchDaemon(com.xpc.example.service.plist): Error Domain=SMAppServiceErrorDomain Code=1 "Operation not permitted" UserInfo={NSLocalizedFailureReason=Operation not permitted} In fact it doesn't seem to be safe to re-register. Any explanation would much appreciated! ===================================================== Side issue #2: I tried to add a similar helper executable as in the original project with register/unregister and put it inside the same app bundle but at a different location like Contents/Helpers/ folder instead of Contents/MacOS. And it always fails with this error: Error Domain=SMAppServiceErrorDomain Code=3 "Codesigning failure loading plist: com.okta.service.osquery code: -67028" UserInfo={NSLocalizedFailureReason=Codesigning failure loading plist: com.okta.service.osquery code: -67028} When I moved the helper binary to Contents/MacOS/ folder along with the main app executable it starts working fine again. Other folders like Resources/XPCServices also don't work. Is it a hard requirement for an executable to be located inside main Contents/MacOS folder in order to be able to call SMAppService register/unregister APIs? I haven't found any documentation regarding this requirement. Thanks, Pavel

I created a macOS app, added an XPC service target, and also added a source editor extension. in The source editor extension‘s perform function. It doesn't work - (void)performCommandWithInvocation:(XCSourceEditorCommandInvocation *)invocation completionHandler:(void (^)(NSError * _Nullable nilOrError))completionHandler { self.xpcConnect = [[NSXPCConnection alloc] initWithServiceName:@"test.TestNewXPCApp.NewXPC"]; NSXPCInterface *interface = [NSXPCInterface interfaceWithProtocol:@protocol(NewXPCProtocol)]; self.xpcConnect.remoteObjectInterface = interface; [self.xpcConnect resume]; [[self.xpcConnect remoteObjectProxy] performCalculationWithNumber:@231 andNumber:@119 withReply:^(NSNumber *reply) { // We have received a response. NSLog(@"ui success%@", reply); }]; But In ViewControler.m, executing the same code , it can work. So why is it possible to connect to the XPC service from within the macOS app, but not from the source editor extension?

There does not seem to be a way to code sign a PAM module so that an XPC service can verify the signature with setCodeSigningRequirement. There should be a way to build a PAM module (dynamic Library ) so it can be code signed. Put in a bundle and code signing the bundle does not work .

When I try to launch my own Java app, I get the following error message. xpcproxy exited due to OS_REASON_CODESIGNING | Launch Constraint Violation, error info: c[5]p[1]m[1]e[0], (Constraint not matched) launch type 3, failure proc [vc: 1]: /bin/bash As far as I know, the failing process path is /bin/bash. This issue is only happening on macOS Sequoia. The Java app works without any issue on MacOS Sonoma or any previous macOS versions. I did not make any changes, including launch constraints or any other settings. After updating to macOS Sequoia, I started getting this error and can no longer launch my app. Thank you so much.

I've developed a Endpoint Security system extension, which will be installed in a container APP. I use XPC to send message from container APP to the ES client, it works fine. I have developed an Endpoint Security system extension that will be installed in a container app. I utilize XPC to send messages from the container app to the ES client, and it functions properly. However, when I attempt to send messages from the ES client to the container app, it always displays an error: 'Couldn’t communicate with a helper application.'. I have removed the sandbox capability of the container app and also employed the same app group for both the ES client and the container app. When an XPC client is connected, I use the following code in the ES client to establish two-way communication. - (BOOL)listener:(NSXPCListener *)listener shouldAcceptNewConnection:(NSXPCConnection *)newConnection { newConnection.exportedInterface = [NSXPCInterface interfaceWithProtocol:@protocol(NXFileGuardXPCProtocol)]; NXFileGuardXPCService *xpcService = [NXFileGuardXPCService sharedInstance]; newConnection.exportedObject = xpcService; // To APP container client (As remote interface) newConnection.remoteObjectInterface = [NSXPCInterface interfaceWithProtocol:@protocol(NXFileGuardXPCClientProtocol)]; [newConnection activate]; self.containerAPPConnection = newConnection; return YES; } But it always fails. How can I deal with this error?

Hello, I run into an issue on Monterey (12.7.5). I have a bundled XPC service in my application which is displaying some stuff and playin sounds via NSSound. I had a problem with playback due to service priority, so I use the trick with a reply block where I send a reply block to the service and basically just retain it and never call it. This worked fine so far, but we have users, predominantly on Monterey, who are having a problem with sound playback. It's choppy and distorted when their machine is under load (where "load" often just means playing a video on YouTube in Chrome). Is there anything else I can do to get the proper priority for my xpc service so I can avoid distorted sound? Additionally the service type is Application and RunLoopType is NSRunLoop with JoinExistingSession set to true. The QoS level of main queue is 0x21 (user interactive) and I'm calling all the NSSound APIs on main queue.