DTS regularly receives questions about how to preserve keychain items across an App ID change, and so I thought I’d post a comprehensive answer here for the benefit of all. If you have any questions or comments, please start a new thread here on the forums. Put it in the Privacy & Security > General subtopic and tag it with Security. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" App ID Prefix Change and Keychain Access The list of keychain access groups your app can access is determined by three entitlements. For the details, see Sharing Access to Keychain Items Among a Collection of Apps. If your app changes its App ID prefix, this list changes and you’re likely to lose access to existing keychain items. This situation crops up under two circumstances: When you migrate your app from using a unique App ID prefix to using your Team ID as its App ID prefix. When you transfer your app to another team. In both cases you have to plan carefully for this change. If you only learn about the problem after you’ve made the change, consider undoing the change to give you time to come up with a plan before continuing. Note On macOS, the information in this post only applies to the data protection keychain. For more information about the subtleties of the keychain on macOS, see On Mac Keychains. For more about App ID prefix changes, see Technote 2311 Managing Multiple App ID Prefixes and QA1726 Resolving the Potential Loss of Keychain Access warning. Migrate From a Unique App ID Prefix to Your Team ID Historically each app was assigned its own App ID prefix. This is no longer the case. Best practice is for apps to use their Team ID as their App ID prefix. This enables multiple neat features, including keychain item sharing and pasteboard sharing. If you have an app that uses a unique App ID prefix, consider migrating it to use your Team ID. This is a good thing in general, as long as you manage the migration process carefully. Your app’s keychain access group list is built from three entitlements: keychain-access-groups — For more on this, see Keychain Access Groups Entitlement. application-identifier (com.apple.application-identifier on macOS) com.apple.security.application-groups — For more on this, see App Groups Entitlement. Keycahin access groups from the third bullet are call app group identified keychain access groups, or AGI keychain access groups for short. IMPORTANT A macOS app can only use an AGI keychain access group if all of its entitlement claims are validated by a provisioning profile. See App Groups: macOS vs iOS: Working Towards Harmony for more about this concept. Keychain access groups from the first two bullets depend on the App ID prefix. If that changes, you lose access to any keychain items in those groups. WARNING Think carefully before using the keychain to store secrets that are the only way to access irreplaceable user data. While the keychain is very reliable, there are situations where a keychain item can be lost and it’s bad if it takes the user’s data with it. In some cases losing access to keychain items is not a big deal. For example, if your app uses the keychain to manage a single login credential, losing that is likely to be acceptable. The user can recover by logging in again. In other cases losing access to keychain items is unacceptable. For example, your app might manage access to dozens of different servers, each with unique login credentials. Your users will be grumpy if you require them to log in to all those servers again. In such situations you must carefully plan your migration. The key thing to understand is that an app group is tied to your team, not your App ID prefix, and thus your app retains access to AGI keychain access groups across an App ID prefix change. This suggests the following approach: Release a version of your app that moves keychain items from other keychain access groups to an AGI keychain access group. Give your users time to update to this new version, run it, and so move their keychain items. When you’re confident that the bulk of your users have done this, change your App ID prefix. The approach has one obvious caveat: It’s hard to judge how long to wait at step 2. Transfer Your App to Another Team Historically there was no supported way to maintain access to keychain items across an app transfer. That’s no longer the case, but you must still plan the transfer carefully. The overall approach is: Identify an app group ID to transfer. This could be an existing app group ID, but in many cases you’ll want to register a new app group ID solely for this purpose. Use the old team (the transferor) to release a version of your app that moves keychain items from other keychain access groups to the AGI keychain access group for this app group ID. Give your users time to update to this new version, run it, and so move their keychain items. When you’re confident that the bulk of your users have done this, initiate the app transfer. Once that’s complete, transfer the app group ID you selected in step 1. See App Store Connect Help > Transfer an app > Overview of app transfer > Apps using App Groups. Publish an update to your app from the new team (the transferee). When a user installs this version, it will have access to your app group, and hence your keychain items. WARNING Once you transfer the app group, the old team won’t be able to publish a new version of any app that uses this app group. That makes step 1 in the process critical. If you have an existing app group that’s used solely by the app being transferred — for example, an app group that you use to share state between the app and its app extensions — then choosing that app group ID makes sense. On the other hand, choosing the ID of an app group that’s share between this app and some unrelated app, one that’s not being transferred, would be bad, because any updates to that other app will lose access to the app group. There are some other significant caveats: The process doesn’t work for Mac apps because Mac apps that have ever used an app group can’t be transferred. See App Store Connect Help > Transfer an app > App transfer criteria. If and when that changes, you’ll need to choose an iOS-style app group ID for your AGI keychain access group. For more about the difference between iOS- and macOS-style app group IDs, see App Groups: macOS vs iOS: Working Towards Harmony. The current transfer process of app groups exposes a small window where some other team can ‘steal’ your app group ID. We have a bug on file to improve that process (r. 171616887). The process works best when transferring between two teams that are both under the control of the same entity. If that’s not the case, take steps to ensure that the old team transfers the app group in step 5. When you submit the app from the new team (step 6), App Store Connect will warn you about a potential loss of keychain access. That warning is talking about keychain items in normal keychain access groups. Items in an AGI keychain access group will still be accessible as long as you transfer the app group. Alternative Approaches for App Transfer In addition to the technique described in the previous section, there are a some alternative approaches you should at consider: Do nothing Do not transfer your app Get creative Do Nothing In this case the user loses all the secrets that your app stored in the keychain. This may be acceptable for certain apps. For example, if your app uses the keychain to manage a single login credential, losing that is likely to be acceptable. The user can recover by logging in again. Do Not Transfer Another option is to not transfer your app. Instead, ship a new version of the app from the new team and have the old app recommend that the user upgrade. There are a number of advantages to this approach. The first is that there’s absolutely no risk of losing any user data. The two apps are completely independent. The second advantage is that the user can install both apps on their device at the same time. This opens up a variety of potential migration paths. For example, you might ship an update to the old app with an export feature that saves the user’s state, including their secrets, to a suitably encrypted file, and then match that with an import facility on the new app. Finally, this approach offers flexible timing. The user can complete their migration at their leisure. However, there are a bunch of clouds to go with these silver linings: Your users might never migrate to the new app. If this is a paid app, or an app with in-app purchase, the user will have to buy things again. You lose the original app’s history, ratings, reviews, and so on. Get Creative Finally, you could attempt something creative. For example, you might: Publish a new version of the app that supports exporting the user’s state, including the secrets. Tell your users to do this, with a deadline. Transfer the app and then, when the deadline expires, publish the new version with an import feature. Frankly, this isn’t very practical. The problem is with step 2: There’s no good way to get all your users to do the export, and if they don’t do it before the deadline there’s no way to do it after. Test Before You Ship Once you have a new version of your app, with the new App ID prefix, it’s time to test. To run a day-to-day test: On a test device, install the existing version of the app from the App Store. Use the app to generate keychain items as a normal user would. For example, if you store login credentials in the keychain, use the app to save such a credential. In Xcode, run the new version of your app. Check that the keychain items you created in step 2 still work. After you upload this new version to App Store Connect, use TestFlight to run an internal test: On a test device, install the existing version of the app from the App Store. Use the app to generate keychain items as a normal user. For example, if you store login credentials in the keychain, use the app to save such a credential. Use TestFlight to update the app to your new version. Check that the keychain items you created in step 2 still work. Do this before you release the app to your beta testers and then again before releasing it to customers. WARNING These TestFlight test are your last chance to ensure that everything works. If you detect an error at this stage, you still have a chance to fix it. Revision History 2026-04-07 Added the Test Before You Ship section. 2026-03-31 Rewrote the Transfer Your App to Another Team section to describe a new approach for preserving access to keychain items across app transfers. Moved the previous discussion into a new Alternative Approaches for App Transfer section. Clarified that a macOS program can now use an app group as a keychain access group as long as its entitlements are validated. Made numerous editorial changes. 2022-05-17 First posted.

With the new ios 26 update, certain numbers will be filtered into other inboxes within imessage. What numbers are classified as "known", and will not be moved into these filters. Do they need to be a contact in your phone, or if a business texts you how will that be filtered?

Hi, I am in need of your help with publishing my game. I got the following explanation for the negative review of my app/game. Issue Description One or more purpose strings in the app do not sufficiently explain the use of protected resources. Purpose strings must clearly and completely describe the app's use of data and, in most cases, provide an example of how the data will be used. Next Steps Update the local network information purpose string to explain how the app will use the requested information and provide a specific example of how the data will be used. See the attached screenshot. Resources Purpose strings must clearly describe how an app uses the ability, data, or resource. The following are hypothetical examples of unclear purpose strings that would not pass review: "App would like to access your Contacts" "App needs microphone access" See examples of helpful, informative purpose strings. The problem is that they say my app asks to allow my app to find devices on local networks. And that this needs more explanation in the purpose strings. Totally valid to ask, but the problem is my app doesn't need local access to devices, and there shouldn't be code that asks this?? FYI the game is build with Unity. Would love some help on how to turn this off so that my app can get published.

Hi, We're in the process of implementing Apple's App Integrity, but am getting stalled due to missing documents. Can anyone assist with this? We've been following https://developer.apple.com/documentation/devicecheck/validating-apps-that-connect-to-your-server to make the necessary updates, but have come up short with where the document references decoding the Attestation Object. Can we get more information here and how the decoding process work?

Hi everyone, I'm integrating Apple's DeviceCheck API into my app and have run into a strange issue that I can't find documented anywhere. The Problem When I call Apple's DeviceCheck query endpoint (POST https://api.devicecheck.apple.com/v1/query_two_bits), the response occasionally returns a last_update_time value that is in the future — ahead of the current server time. Example response: { "bit0": true, "bit1": false, "last_update_time": "2026-05" // future month, not yet reached } What I've Checked My server's system clock is correctly synced via NTP The JWT token I generate uses the current timestamp for the iat field This doesn't happen on every device — only on some specific devices The issue is reproducible on the same device across multiple calls Questions Is last_update_time sourced from the device's local clock at the time update_two_bits was called? Or is it stamped server-side by Apple? Could a device with an incorrectly set system clock (set to the future) cause Apple's servers to record a future last_update_time? Is there a recommended way to validate or sanitize last_update_time on the server side to handle this edge case? Has anyone else encountered this behavior? Any known workarounds? Any insight would be greatly appreciated. Thanks!

Can a macOS Platform SSO extension reliably identify the original app behind a Safari or ASWebAuthenticationSession-mediated request, or does ASAuthorizationProviderExtensionAuthorizationRequest only expose the immediate caller such as Safari ? We are seeing: callerBundleIdentifier = com.apple.Safari callerTeamIdentifier = Apple audit-token-based validation also resolves to Safari So the question is whether this is the expected trust model, and if so, what Apple-recommended mechanism should be used to restrict SSO participation to approved apps when the flow is browser-mediated.

I'm trying to use ASWebAuthenticationSession on macOS but there is a weird crash and I have no idea what to do. It looks like there is a main thread check in a framework code that I have no control over. Any help would be appreciated. Thank you in advance. The stack of crashed thread has no symbols, even for supposedly my code in OAuthClient.authenticate. macOS 15.4.1 (24E263) Xcode Version 16.3 (16E140) Thread 11: EXC_BREAKPOINT (code=1, subcode=0x10039bb04) Thread 12 Queue : com.apple.NSXPCConnection.m-user.com.apple.SafariLaunchAgent (serial) #0 0x0000000100b17b04 in _dispatch_assert_queue_fail () #1 0x0000000100b52834 in dispatch_assert_queue$V2.cold.1 () #2 0x0000000100b17a88 in dispatch_assert_queue () #3 0x000000027db5f3e8 in swift_task_isCurrentExecutorWithFlagsImpl () #4 0x00000001022c7754 in closure #1 in closure #1 in OAuthClient.authenticate() () #5 0x00000001022d0c98 in thunk for @escaping @callee_guaranteed (@in_guaranteed URL?, @guaranteed Error?) -> () () #6 0x00000001c7215a34 in __102-[ASWebAuthenticationSession initWithURL:callback:usingEphemeralSession:jitEnabled:completionHandler:]_block_invoke () #7 0x00000001c72163d0 in -[ASWebAuthenticationSession _endSessionWithCallbackURL:error:] () #8 0x00000001c7215fc0 in __43-[ASWebAuthenticationSession _startDryRun:]_block_invoke_2 () #9 0x0000000194e315f4 in __invoking___ () #10 0x0000000194e31484 in -[NSInvocation invoke] () #11 0x00000001960fd644 in __NSXPCCONNECTION_IS_CALLING_OUT_TO_REPLY_BLOCK__ () #12 0x00000001960fbe40 in -[NSXPCConnection _decodeAndInvokeReplyBlockWithEvent:sequence:replyInfo:] () #13 0x00000001960fb798 in __88-[NSXPCConnection _sendInvocation:orArguments:count:methodSignature:selector:withProxy:]_block_invoke_3 () #14 0x0000000194a6ef18 in _xpc_connection_reply_callout () #15 0x0000000194a6ee08 in _xpc_connection_call_reply_async () #16 0x0000000100b3130c in _dispatch_client_callout3_a () #17 0x0000000100b362f8 in _dispatch_mach_msg_async_reply_invoke () #18 0x0000000100b1d3a8 in _dispatch_lane_serial_drain () #19 0x0000000100b1e46c in _dispatch_lane_invoke () #20 0x0000000100b2bfbc in _dispatch_root_queue_drain_deferred_wlh () #21 0x0000000100b2b414 in _dispatch_workloop_worker_thread () #22 0x0000000100c0379c in _pthread_wqthread () My code: @MainActor func authenticate() async throws { let authURL = api.authorizationURL( scopes: scopes, state: state, redirectURI: redirectURI ) let authorizationCodeURL: URL = try await withUnsafeThrowingContinuation { c in let session = ASWebAuthenticationSession(url: authURL, callback: .customScheme(redirectScheme)) { url, error in guard let url = url else { c.resume(throwing: error ?? Error.unknownError("Failed to get authorization code")) return } c.resume(returning: url) } session.presentationContextProvider = presentationContextProvider session.start() } let authorizationCode = try codeFromAuthorizationURL(authorizationCodeURL) (storedAccessToken, storedRefreshToken) = try await getTokens(authorizationCode: authorizationCode) } Here is disassembly of the crashed function. libdispatch.dylib`_dispatch_assert_queue_fail: 0x10067fa8c <+0>: pacibsp 0x10067fa90 <+4>: sub sp, sp, #0x50 0x10067fa94 <+8>: stp x20, x19, [sp, #0x30] 0x10067fa98 <+12>: stp x29, x30, [sp, #0x40] 0x10067fa9c <+16>: add x29, sp, #0x40 0x10067faa0 <+20>: adrp x8, 71 0x10067faa4 <+24>: add x8, x8, #0x951 ; "not " 0x10067faa8 <+28>: adrp x9, 70 0x10067faac <+32>: add x9, x9, #0x16b ; "" 0x10067fab0 <+36>: stur xzr, [x29, #-0x18] 0x10067fab4 <+40>: cmp w1, #0x0 0x10067fab8 <+44>: csel x8, x9, x8, ne 0x10067fabc <+48>: ldr x10, [x0, #0x48] 0x10067fac0 <+52>: cmp x10, #0x0 0x10067fac4 <+56>: csel x9, x9, x10, eq 0x10067fac8 <+60>: stp x9, x0, [sp, #0x10] 0x10067facc <+64>: adrp x9, 71 0x10067fad0 <+68>: add x9, x9, #0x920 ; "BUG IN CLIENT OF LIBDISPATCH: Assertion failed: " 0x10067fad4 <+72>: stp x9, x8, [sp] 0x10067fad8 <+76>: adrp x1, 71 0x10067fadc <+80>: add x1, x1, #0x8eb ; "%sBlock was %sexpected to execute on queue [%s (%p)]" 0x10067fae0 <+84>: sub x0, x29, #0x18 0x10067fae4 <+88>: bl 0x1006c258c ; symbol stub for: asprintf 0x10067fae8 <+92>: ldur x19, [x29, #-0x18] 0x10067faec <+96>: str x19, [sp] 0x10067faf0 <+100>: adrp x0, 71 0x10067faf4 <+104>: add x0, x0, #0x956 ; "%s" 0x10067faf8 <+108>: bl 0x1006b7b64 ; _dispatch_log 0x10067fafc <+112>: adrp x8, 108 0x10067fb00 <+116>: str x19, [x8, #0x2a8] -> 0x10067fb04 <+120>: brk #0x1

Steps to reproduce: register a passkey on device A authenticate on device A, using the prf extension and a constant salt. Note the prf output go to device B. wait for iCloud sync authenticate on device B using the prf extension and the same constant salt. Note the prf output The prf outputs are different. Note: Repeat the authentication on each device. The prf output is identical for a given device, which seems to point towards the inclusion of a device specific component in the prf derivation. In my scenario, I need the prf output to be the same regardless of the device since I use it as the recovery key for my app data. Could you confirm that this is the expected behavior or not? Thanks,

Hello, When using ASWebAuthenticationSession with an HTTPS callback URL (Universal Link), I receive the following error: Authorization error: The operation couldn't be completed. Application with identifier jp.xxxx.yyyy.dev is not associated with domain xxxx-example.go.link. Using HTTPS callbacks requires Associated Domains using the webcredentials service type for xxxx-example.go.link. I checked Apple’s official documentation but couldn’t find any clear statement that webcredentials is required when using HTTPS callbacks in ASWebAuthenticationSession. What I’d like to confirm: Is webcredentials officially required when using HTTPS as a callback URL with ASWebAuthenticationSession? If so, is there any official documentation or technical note that states this requirement? Environment iOS 18.6.2 Xcode 16.4 Any clarification or official references would be greatly appreciated. Thank you.

While I was submitting a new feedback today for an iPhone/iPad storage issue, I saw a new log called “iOS storage log”. I could find no reference to this when I searched online. It made me wonder if it was new and if it contained personal data? Most of us only have one device, with all our personal data. Therefore, I’d appreciate any input on what personal data these logs contain.

hello, My organization has an outlook add-in that requires auth into our platform. As Microsoft forces Auth on MacOS to use WKWebView https://learn.microsoft.com/en-us/office/dev/add-ins/concepts/browsers-used-by-office-web-add-ins, we are running into a situation that we cannot use passkeys as an auth method as we are unable to trigger WebAuthN flows. We’ve raised this in Microsoft side but they have deferred to Apple given WKWebView is Safari based. This is a big blocker for us to achieve a full passwordless future. Has anyone come across this situation? Thank you.

Our proposed solution to identify an app user when opening a website operated by app developer is: Apps sends a request to backed with app users auth header Backend fetches a generated authenticated url from website backend, based on users auth header App opens it in browser The browser journey is self contained within domain of the business. Would this interaction require an ATT request given that the users identity cannot be tracked back to the app user ? Thanks

I regularly see folks confused by the difference in behaviour of app groups between macOS and iOS. There have been substantial changes in this space recently. While much of this is now covered in the official docs (r. 92322409), I’ve updated this post to go into all the gory details. If you have questions or comments, start a new thread with the details. Put it in the App & System Services > Core OS topic area and tag it with Code Signing and Entitlements. Oh, and if your question is about app group containers, also include Files and Storage. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" App Groups: macOS vs iOS: Working Towards Harmony There are two styles of app group ID: iOS-style app group IDs start with group., for example, group.eskimo1.test. macOS-style app group IDs start with your Team ID, for example, SKMME9E2Y8.eskimo1.test. This difference has been the source of numerous weird problems over the years. Starting in Feb 2025, iOS-style app group IDs are fully supported on macOS for all product types [1]. If you’re writing new code that uses app groups, use an iOS-style app group ID. If you have existing code that uses a macOS-style app group ID, consider how you might transition to the iOS style. IMPORTANT The Feb 2025 changes aren’t tied to an OS release but rather to a Developer website update. For more on this, see Feb 2025 Changes, below. [1] If your product is a standalone executable, like a daemon or agent, wrap it in an app-like structure, as explained in Signing a daemon with a restricted entitlement. iOS-Style App Group IDs An iOS-style app group ID has the following features: It starts with the group. prefix, for example, group.eskimo1.test. You allocate it on the Developer website. This assigns the app group ID to your team. You then claim access to it by listing it in the App Groups entitlement (com.apple.security.application-groups) entitlement. That claim must be authorised by a provisioning profile [1]. The Developer website will only let you include your team’s app group IDs in your profile. For more background on provisioning profiles, see TN3125 Inside Code Signing: Provisioning Profiles. iOS-style app group IDs originated on iOS with iOS 3.0. They’ve always been supported on iOS’s child platforms (iPadOS, tvOS, visionOS, and watchOS). On the Mac: They’ve been supported by Mac Catalyst since that technology was introduced. Likewise for iOS Apps on Mac. Starting in Feb 2025, they’re supported for other Mac products. [1] Strictly speaking macOS does not require that, but if your claim is not authorised by a profile then you might run into other problems. See Entitlements-Validated Flag, below. macOS-Style App Group IDs A macOS-style app group ID has the following features: It should start with your Team ID [1], for example, SKMME9E2Y8.eskimo1.test. It can’t be explicitly allocated on the Developer website. Code that isn’t sandboxed doesn’t need to claim the app group ID in the App Groups entitlement. [2] To use an app group, claim the app group ID in the App Groups entitlement. The App Groups entitlement is not restricted on macOS, meaning that this claim doesn’t need to be authorised by a provisioning profile [3]. However, if you claim an app group ID that’s not authorised in some way, you might run into problems. More on that later in this post. If you submit an app to the Mac App Store, the submission process checks that your app group IDs make sense, that is, they either start with your Team ID (macOS style) or are assigned to your team (iOS style). [1] This is “should” because, historically, macOS has not actually required it. However, that’s now changing, with things like app group container protection. [2] This was true prior to macOS 15. It may still technically be true in macOS 15 and later, but the most important thing, access to the app group container, requires the entitlement because of app group container protection. [3] Technically it’s a validation-required entitlement, something that we’ll come back to in the Entitlements-Validated Flag section. Feb 2025 Changes On 21 Feb 2025 we rolled out a change to the Developer website that completes the support for iOS-style app group IDs on the Mac. Specifically, it’s now possible to create a Mac provisioning profile that authorises the use of an iOS-style app group ID. Note This change doesn’t affect Mac Catalyst or iOS Apps on Mac, which have always been able to use iOS-style app group IDs on the Mac. Prior to this change it was possible to use an iOS-style app group ID on the Mac but that might result in some weird behaviour. Later sections of this post describe some of those problems. Of course, that information is now only of historical interest because, if you’re using an iOS-style app group, you can and should authorise that use with a provisioning profile. We also started seeding Xcode 16.3, which has since been release. This is aware of the Developer website change, and its Signing & Capabilities editor actively encourages you to use iOS-style app groups IDs in all products. Note This Xcode behaviour is the only option for iOS and its child platforms. With Xcode 16.3, it’s now the default for macOS as well. If you have existing project, enable this behaviour using the Register App Groups build setting. Finally, we updated a number of app group documentation pages, including App Groups entitlement and Configuring app groups. Crossing the Streams In some circumstances you might need to have a single app that accesses both an iOS- and a macOS-style app group. For example: You have a macOS app. You want to migrate to an iOS-style app group ID, perhaps because you want to share an app group container with a Mac Catalyst app. But you also need to access existing content in a container identified by a macOS-style app group ID. Historically this caused problems (FB16664827) but, as of Jun 2025, this is fully supported (r. 148552377). When the Developer website generates a Mac provisioning profile for an App ID with the App Groups capability, it automatically adds TEAM_ID.* to the list of app group IDs authorised by that profile (where TEAM_ID is your Team ID). This allows the app to claim access to every iOS-style app group ID associated with the App ID and any macOS-style app group IDs for that team. This helps in two circumstances: It avoids any Mac App Store Connect submission problems, because App Store Connect can see that the app’s profile authorises its use of all the it app group IDs it claims access to. Outside of App Store — for example, when you directly distribute an app using Developer ID signing — you no longer have to rely on macOS granting implicit access to macOS-style app group IDs. Rather, such access is explicitly authorised by your profile. That ensures that your entitlements remain validated, as discussed in the Entitlements-Validated Flag, below. A Historical Interlude These different styles of app group IDs have historical roots: On iOS, third-party apps have always used provisioning profiles, and thus the App Groups entitlement is restricted just like any other entitlement. On macOS, support for app groups was introduced before macOS had general support for provisioning profiles [1], and thus the App Groups entitlement is unrestricted. The unrestricted nature of this entitlement poses two problems. The first is accidental collisions. How do you prevent folks from accidentally using an app group ID that’s in use by some other developer? On iOS this is easy: The Developer website assigns each app group ID to a specific team, which guarantees uniqueness. macOS achieved a similar result by using the Team ID as a prefix. The second problem is malicious reuse. How do you prevent a Mac app from accessing the app group containers of some other team? Again, this isn’t an issue on iOS because the App Groups entitlement is restricted. On macOS the solution was for the Mac App Store to prevent you from publishing an app that used an app group ID that’s used by another team. However, this only works for Mac App Store apps. Directly distributed apps were free to access app group containers of any other app. That was considered acceptable back when the Mac App Store was first introduced. That’s no longer the case, which is why macOS 15 introduced app group container protection. See App Group Container Protection, below. [1] I’m specifically talking about provisioning profiles for directly distributed apps, that is, apps using Developer ID signing. Entitlements-Validated Flag The fact that the App Groups entitlement is unrestricted on macOS is, when you think about it, a little odd. The purpose of entitlements is to gate access to functionality. If an entitlement isn’t restricted, it’s not much of a gate! For most unrestricted entitlements that’s not a problem. Specifically, for both the App Sandbox and Hardened Runtime entitlements, those are things you opt in to, so macOS is happy to accept the entitlement at face value. After all, if you want to cheat you can just not opt in [1]. However, this isn’t the case for the App Groups entitlement, which actually gates access to functionality. Dealing with this requires macOS to walk a fine line between security and compatibility. Part of that solution is the entitlements-validated flag. When a process runs an executable, macOS checks its entitlements. There are two categories: Restricted entitlements must be authorised by a provisioning profile. If your process runs an executable that claims a restricted entitlement that’s not authorised by a profile, the system traps. Unrestricted entitlements don’t have to be authorised by a provisioning profile; they can be used by any code at any time. However, the App Groups entitlement is a special type of unrestricted entitlement called a validation-required entitlement. If a process runs an executable that claims a validation-required entitlement and that claim is not authorised by a profile, the system allows the process to continue running but clears its entitlements-validated flag. Some subsystems gate functionality on the entitlements-validated flag. For example, the data protection keychain uses entitlements as part of its access control model, but refuses to honour those entitlements if the entitlement-validated flag has been cleared. Note If you’re curious about this flag, use the procinfo subcommand of launchctl to view it. For example: % sudo launchctl procinfo `pgrep Test20230126` … code signing info = valid … entitlements validated … If the flag has been cleared, this line will be missing from the code signing info section. Historically this was a serious problem because it prevented you from creating an app that uses both app groups and the data protection keychain [2] (r. 104859788). Fortunately that’s no longer an issue because the Developer website now lets you include the App Groups entitlement in macOS provisioning profiles. [1] From the perspective of macOS checking entitlements at runtime. There are other checks: The App Sandbox is mandatory for Mac App Store apps, but that’s checked when you upload the app to App Store Connect. Directly distributed apps must be notarised to pass Gatekeeper, and the notary service requires that all executables enable the hardened runtime. [2] See TN3137 On Mac keychain APIs and implementations for more about the data protection keychain. App Groups and the Keychain The differences described above explain a historical oddity associated with keychain access. The Sharing access to keychain items among a collection of apps article says: Application groups When you collect related apps into an application group using the App Groups entitlement, they share access to a group container, and gain the ability to message each other in certain ways. You can use app group names as keychain access group names, without adding them to the Keychain Access Groups entitlement. On iOS this makes a lot of sense: The App Groups entitlement is a restricted entitlement on iOS. The Developer website assigns each iOS-style app group ID to a specific team, which guarantees uniqueness. The required group. prefix means that these keychain access groups can’t collide with other keychain access groups, which all start with an App ID prefix (there’s also Apple-only keychain access groups that start with other prefixes, like apple). However, this didn’t work on macOS [1] because the App Groups entitlement is unrestricted there. However, with the Feb 2025 changes it should now be possible to use an iOS-style app group ID as a keychain access group on macOS. Note I say “should” because I’ve not actually tried it (-: Keep in mind that standard keychain access groups are protected the same way on all platforms, using the restricted Keychain Access Groups entitlement (keychain-access-groups). [1] Except for Mac Catalyst apps and iOS Apps on Mac. Not Entirely Unsatisfied When you launch a Mac app that uses app groups you might see this log entry: type: error time: 10:41:35.858009+0000 process: taskgated-helper subsystem: com.apple.ManagedClient category: ProvisioningProfiles message: com.example.apple-samplecode.Test92322409: Unsatisfied entitlements: com.apple.security.application-groups Note The exact format of that log entry, and the circumstances under which it’s generated, varies by platform. On macOS 13.0.1 I was able to generate it by running a sandboxed app that claims a macOS-style app group ID in the App Groups entitlement and also claims some other restricted entitlement. This looks kinda worrying and can be the source of problems. It means that the App Groups entitlement claims an entitlement that’s not authorised by a provisioning profile. On iOS this would trap, but on macOS the system allows the process to continue running. It does, however, clear the entitlements-validate flag. See Entitlements-Validated Flag for an in-depth discussion of this. The easiest way to avoid this problem is to authorise your app group ID claims with a provisioning profile. If there’s some reason you can’t do that, watch out for potential problems with: The data protection keychain — See the discussion of that in the Entitlements-Validated Flag and App Groups and the Keychain sections, both above. App group container protection — See App Group Container Protection, below. App Group Container Protection macOS 15 introduced app group container protection. To access an app group container without user intervention: Claim access to the app group by listing its ID in the App Groups entitlement. Locate the container by calling the containerURL(forSecurityApplicationGroupIdentifier:) method. Ensure that at least one of the following criteria are met: Your app is deployed via the Mac App Store (A). Or via TestFlight when running on macOS 15.1 or later (B). Or the app group ID starts with your app’s Team ID (C). Or your app’s claim to the app group is authorised by a provisioning profile embedded in the app (D) [1]. If your app doesn’t follow these rules, the system prompts the user to approve its access to the container. If granted, that consent applies only for the duration of that app instance. For more on this, see: The System Integrity Protection section of the macOS Sequoia 15 Release Notes The System Integrity Protection section of the macOS Sequoia 15.1 Release Notes WWDC 2024 Session 10123 What’s new in privacy, starting at 12:23 The above criteria mean that you rarely run into the app group authorisation prompt. If you encounter a case where that happens, feel free to start a thread here on DevForums. See the top of this post for info on the topic and tags to use. Note Prior to the Feb 2025 change, things generally worked out fine when you app was deployed but you might’ve run into problems during development. That’s no longer the case. [1] This is what allows Mac Catalyst and iOS Apps on Mac to work. Revision History 2025-08-12 Added a reference to the Register App Groups build setting. 2025-07-28 Updated the Crossing the Streams section for the Jun 2025 change. Made other minor editorial changes. 2025-04-16 Rewrote the document now that iOS-style app group IDs are fully supported on the Mac. Changed the title from App Groups: macOS vs iOS: Fight! to App Groups: macOS vs iOS: Working Towards Harmony 2025-02-25 Fixed the Xcode version number mentioned in yesterday’s update. 2025-02-24 Added a quick update about the iOS-style app group IDs on macOS issue. 2024-11-05 Further clarified app group container protection. Reworked some other sections to account for this new reality. 2024-10-29 Clarified the points in App Group Container Protection. 2024-10-23 Fleshed out the discussion of app group container protection on macOS 15. 2024-09-04 Added information about app group container protection on macOS 15. 2023-01-31 Renamed the Not Entirely Unsatisfactory section to Not Entirely Unsatisfied. Updated it to describe the real impact of that log message. 2022-12-12 First posted.

Hi everyone, I’ve been working on an experimental prototype called FaceBridge that explores whether Secure Enclave–backed biometric authorization can be delegated between macOS and iPhone using only public Apple APIs. The goal of the project was to better understand the architectural boundaries of cross-device trust and approval flows that resemble Apple’s built-in Touch ID / Continuity authorization experiences. FaceBridge implements a local authorization pipeline where: macOS generates a signed authorization request the request is delivered to a trusted nearby iPhone over BLE / Network framework the iPhone verifies sender identity Face ID approval is requested using LocalAuthentication the iPhone signs the approval response using Secure Enclave–backed keys macOS validates the response and unlocks a protected action Security properties currently implemented: • Secure Enclave–backed signing identities per device • cryptographic device pairing and trust persistence • replay protection using nonce + timestamp binding • structured authorization request/response envelopes • signed responder identity verification • trusted-device registry model • local encrypted transport over BLE and local network This is intentionally not attempting to intercept or replace system-level Touch ID dialogs (App Store installs, Keychain prompts, loginwindow, etc.), but instead explores what is possible within application-level authorization boundaries using public APIs only. The project is open source: https://github.com/wesleysfavarin/facebridge Technical architecture write-up: https://medium.com/@wesleysfavarin/facebridge I’m particularly interested in feedback around: • recommended Secure Enclave identity lifecycle patterns • best practices for cross-device trust persistence • LocalAuthentication usage in delegated approval scenarios • whether similar authorization models are expected to become more formally supported across Apple platforms in the future Thanks in advance for any guidance or suggestions.

https://developer.apple.com/documentation/apptrackingtransparency/attrackingmanager/authorizationstatus/notdetermined Note: Discussion If you call ATTrackingManager.trackingAuthorizationStatus in macOS, the result is always ATTrackingManager.AuthorizationStatus.notDetermined. So, does macOS support getting ATT?

Trusted execution is a generic name for a Gatekeeper and other technologies that aim to protect users from malicious code. General: Forums topic: Code Signing Forums tag: Gatekeeper Developer > Signing Mac Software with Developer ID Apple Platform Security support document Safely open apps on your Mac support article Hardened Runtime document WWDC 2022 Session 10096 What’s new in privacy covers some important Gatekeeper changes in macOS 13 (starting at 04: 32), most notably app bundle protection WWDC 2023 Session 10053 What’s new in privacy covers an important change in macOS 14 (starting at 17:46), namely, app container protection WWDC 2024 Session 10123 What’s new in privacy covers an important change in macOS 15 (starting at 12:23), namely, app group container protection Updates to runtime protection in macOS Sequoia news post Testing a Notarised Product forums post Resolving Trusted Execution Problems forums post App Translocation Notes (aka Gatekeeper path randomisation) forums post Most trusted execution problems are caused by code signing or notarisation issues. See Code Signing Resources and Notarisation Resources. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

Hello I'm using Auth0 for handling auth in my app When the user wants to sign in, it will show the auth system pop-up And when the user wants to log out it shows the same pop-up My issue is how to replace the Sign In text in this pop-up to show Sign Out instead of Sign In when the user wants to sign out?

Hello, Is there any way to detect if the iOS screen is currently being shared via FaceTime or iPhone Mirroring? Our application relies on this information to help ensure that users are not accessing it from one location while physically being in another.

Our company has a micro service which sends a notification email to an iCloud account/email and the email is going to the junk folder. As we tested, the email generated from user-field.company.com goes to the Inbox, while the email from user-dev.company.com goes to the Junk folder. Is there a way to avoid sending the emails to client's Junk folder when the email is sent from a specific company domain?

We’ve identified an issue in our app where, upon clicking the "Call Customer Center" button, users are unexpectedly shown a logo and message option on a native pop-up window. However, this wasn't the case before, and it should only display a phone number to dial, which was given inside our code. This is incorrect and misleading for our users, as: We are a Canadian-based service and have no affiliation with US messaging chat. The messaging feature was never enabled or intended for our app. Our app should only initiate a phone call to our customer support center — no messages or branding from third parties should appear