The One-time codes documentation details how to enable autofill for SMS based codes. However, there is no details about how to correctly implement autofill for email based codes. I am observing the email based autofill works inconsistently when using email based OTC. In my application: There is latency of 10-15 seconds from when the email arrives to when it is available for autofill. After the autofill feature is used, the OTC email is not being deleted from the inbox automatically. Without documentation, it's unclear to me what I might be doing wrong that is causing these side effects. I found an ietf proposal for how autofill with email based codes might work, but it’s unclear if this is how Apple has implemented the feature: https://www.ietf.org/archive/id/draft-wells-origin-bound-one-time-codes-00.html#name-email Existing docs for Autofill using SMS: https://developer.apple.com/documentation/security/enabling-autofill-for-domain-bound-sms-codes

I have a binary executable which needs to be given Accessibility Permissions so it can inject keypresses and mouse moves. This was always possible up to macOS 15 - when the first keypress arrived the Accessibility Permissions window would open and allow me to add the executable. However this no longer works in macOS 26: the window still opens, I navigate to the executable file and select it but it doesn't appear in the list. No error message appears. I'm guessing that this may be due to some tightening of security in Tahoe but I need to figure out what to change with my executable to allow it to work.

Hi! We are developing an authentication plugin for macOS that integrates with the system's authentication flow. The plugin is designed to prompt the user for approval via a push notification in our app before allowing access. The plugin is added as the first mechanism in the authenticate rule, followed by the default builtin:authenticate as a fallback. When the system requests authentication (e.g., during screen unlock), our plugin successfully displays the custom UI and sends a push notification to the user's device. However, I've encountered the following issue: If the user does not approve the push notification within ~30 seconds, the system resets the screen lock (expected behavior). If the user approves the push notification within approximately 30 seconds but doesn’t start entering their password before the timeout expires, the system still resets the screen lock before they can enter their password, effectively canceling the session. What I've Tried: Attempted to imitate mouse movement after the push button was clicked to keep the session active. Created a display sleep prevention assertion using IOKit to prevent the screen from turning off. Used the caffeinate command to keep the display and system awake. Tried setting the result as allow for the authorization request and passing an empty password to prevent the display from turning off. I also checked the system logs when this issue occurred and found the following messages: ___loginwindow: -[LWScreenLock (Private) askForPasswordSecAgent] | localUser = >timeout loginwindow: -[LWScreenLock handleUnlockResult:] _block_invoke | ERROR: Unexpected _lockRequestedBy of:7 sleeping screen loginwindow: SleepDisplay | enter powerd: Process (loginwindow) is requesting display idle___ These messages suggest that the loginwindow process encounters a timeout condition, followed by the display entering sleep mode. Despite my attempts to prevent this behavior, the screen lock still resets prematurely. Questions: Is there a documented (or undocumented) system timeout for the entire authentication flow during screen unlock that I cannot override? Are there any strategies for pausing or extending the authentication timeout to allow for complex authentication flows like push notifications? Any guidance or insights would be greatly appreciated. Thank you!

Summary I am investigating a change in macOS 26.1 (Tahoe) where plain (non-bundled) executables that request screen recording access no longer appear under: System Settings → Privacy & Security → Screen & System Audio Recording This behavior differs from macOS Sequoia, where these executables did appear in the list and could be managed through the UI. Tahoe still prompts for permission and still allows the executable to capture the screen once permission is granted, but the executable never shows up in the UI list. This breaks user expectations and removes UI-based permission management. To confirm the behavior, I created a small reproduction project with both: a plain executable, and an identical executable packaged inside an .app bundle. Only the bundled version appears in System Settings. Observed Behaviour 1. Plain Executable (from my reproduction project) When running a plain executable that captures the screen: macOS displays the normal screen-recording permission prompt. Before granting permission: screenshots show only the desktop background. After granting permission: screenshots capture the full display. The executable does not appear under “Screen & System Audio Recording”. Even when permission is granted manually (e.g., dragging the executable into the pane), the executable still does not appear, which prevents the user from modifying or revoking the permission through the UI. If the executable is launched from inside another app (e.g., VS Code, Terminal), the parent app appears in the list instead, not the executable itself. 2. Bundled App Version (from the reproduction project) I packaged the same code into a simple .app bundle (ScreenCaptureApp.app). When running the app: The same permission prompt appears. Pre-permission screenshots show the desktop background. Post-permission screenshots capture the full display. The app does appear under “Screen & System Audio Recording”. This bundle uses the same underlying executable — the only difference is packaging. Hypothesis macOS 26.1 (Tahoe) appears to require app bundles for an item to be shown in the Screen Recording privacy UI. Plain executables: still request and receive permission, still function correctly after permission is granted, but do not appear in the System Settings list. This may be an intentional change, undocumented behavior, or a regression. Reproduction Project The reproduction project includes: screen_capture.go A simple Go program that captures screenshots in a loop. screen_capture_executable Plain executable built from the Go source. ScreenCaptureApp.app/ App bundle containing the same executable. build.sh Builds both the plain executable and the app bundle. Permission reset and TCC testing scripts. The project demonstrates the behavior consistently. Steps to Reproduce Plain Executable Build: ./build.sh Reset screen capture permissions: sudo tccutil reset ScreenCapture Run: ./screen_capture_executable Before granting: screenshots show desktop only. Grant permission when prompted. After granting: full screenshots. Executable does not appear in “Screen & System Audio Recording”. Bundled App Build (if not already built): ./build.sh Reset permissions (optional): sudo tccutil reset ScreenCapture Run: open ScreenCaptureApp.app Before granting: screenshots show desktop. After granting: full screenshots. App bundle appears in the System Settings list. Additional Check I also tested launching the plain executable as a child process of another executable, similar to how some software architectures work. Result: Permission prompt appears Permission can be granted Executable still does not appear in the UI, even though TCC tracks it internally → consistent with the plain-executable behaviour. This reinforces that only app bundles are listed. Questions for Apple Is the removal of plain executables from “Screen & System Audio Recording” an intentional change in macOS Tahoe? If so, does Apple now require all screen-recording capable binaries to be packaged as .app bundles for the UI to display them? Is there a supported method for making a plain executable (launched by a parent process) appear in the list? If this is not intentional, what is the recommended path for reporting this as a regression? Files Unfortunately, I have discovered the zip file that contains my reproduction project can't be directly uploaded here. Here is a Google Drive link instead: https://drive.google.com/file/d/1sXsr3Q0g6_UzlOIL54P5wbS7yBkpMJ7A/view?usp=sharing Thank you for taking the time to review this. Any insight into whether this change is intentional or a regression would be very helpful.

I'm trying to export and re-import a P-256 private key that was originally generated via SecKeyCreateRandomKey(), but I keep running into roadblocks. The key is simply exported via SecItemExport() with format formatWrappedPKCS8, and I did set a password just to be sure. Do note that I must use the file-based keychain, as the data protection keychain requires a restricted entitlement and I'm not going to pay a yearly fee just to securely store some private keys for a personal project. The 7-day limit for unsigned/self-signed binaries isn't feasible either. Here's pretty much everything I could think of trying: Simply using SecItemImport() does import the key, but I cannot set kSecAttrLabel and more importantly: kSecAttrApplicationTag. There just isn't any way to pass these attributes upfront, so it's always imported as Imported Private Key with an empty comment. Keys don't support many attributes to begin with and I need something that's unique to my program but shared across all the relevant key entries, otherwise it's impossible to query for only my program's keys. kSecAttrLabel is already used for something else and is always unique, which really only leaves kSecAttrApplicationTag. I've already accepted that this can be changed via Keychain Access, as this attribute should end up as the entry's comment. At least, that's how it works with SecKeyCreateRandomKey() and SecItemCopyMatching(). I'm trying to get that same behaviour for imports. Running SecItemUpdate() afterwards to set these 2 attributes doesn't work either, as now the kSecAttrApplicationTag is suddenly used for the entry's label instead of the comment. Even setting kSecAttrComment (just to be certain) doesn't change the comment. I think kSecAttrApplicationTag might be a creation-time attribute only, and since SecItemImport() already created a SecKey I will never be able to set this. It likely falls back to updating the label because it needs to target something that is still mutable? Using SecItemImport() with a nil keychain (i.e. create a transient key), then persisting that with SecItemAdd() via kSecValueRef does allow me to set the 2 attributes, but now the ACL is lost. Or more precise: the ACL does seem to exist as any OS prompts do show the label I originally set for the ACL, but in Keychain Access it shows as Allow all applications to access this item. I'm looking to enable Confirm before allowing access and add my own program to the Always allow access by these applications list. Private keys outright being open to all programs is of course not acceptable, and I can indeed access them from other programs without any prompts. Changing the ACL via SecKeychainItemSetAccess() after SecItemAdd() doesn't seem to do anything. It apparently succeeds but nothing changes. I also reopened Keychain Access to make sure it's not a UI "caching" issue. Creating a transient key first, then getting the raw key via SecKeyCopyExternalRepresentation() and passing that to SecItemAdd() via kSecValueData results in The specified attribute does not exist. This error only disappears if I remove almost all of the attributes. I can pass only kSecValueData, kSecClass and kSecAttrApplicationTag, but then I get The specified item already exists in the keychain errors. I found a doc that explains what determines uniqueness, so here are the rest of the attributes I'm using for SecItemAdd(): kSecClass: not mentioned as part of the primary key but still required, otherwise you'll get One or more parameters passed to a function were not valid. kSecAttrLabel: needed for my use case and not part of the primary key either, but as I said this results in The specified attribute does not exist. kSecAttrApplicationLabel: The specified attribute does not exist. As I understand it this should be the SHA1 hash of the public key, passed as Data. Just omitting it would certainly be an option if the other attributes actually worked, but right now I'm passing it to try and construct a truly unique primary key. kSecAttrApplicationTag: The specified item already exists in the keychain. kSecAttrKeySizeInBits: The specified attribute does not exist. kSecAttrEffectiveKeySize: The specified attribute does not exist. kSecAttrKeyClass: The specified attribute does not exist. kSecAttrKeyType: The specified attribute does not exist. It looks like only kSecAttrApplicationTag is accepted, but still ignored for the primary key. Even entering something that is guaranteed to be unique still results in The specified item already exists in the keychain, so I think might actually be targeting literally any key. I decided to create a completely new keychain and import it there (which does succeed), but the key is completely broken. There's no Kind and Usage at the top of Keychain Access and the table view just below it shows symmetric key instead of private. The kSecAttrApplicationTag I'm passing is still being used as the label instead of the comment and there's no ACL. I can't even delete this key because Keychain Access complains that A missing value was detected. It seems like the key doesn't really contain anything unique for its primary key, so it will always match any existing key. Using SecKeyCreateWithData() and then using that key as the kSecValueRef for SecItemAdd() results in A required entitlement isn't present. I also have to add kSecUseDataProtectionKeychain: false to SecItemAdd() (even though that should already be the default) but then I get The specified item is no longer valid. It may have been deleted from the keychain. This occurs even if I decrypt the PKCS8 manually instead of via SecItemImport(), so it's at least not like it's detecting the transient key somehow. No combination of kSecAttrIsPermanent, kSecUseDataProtectionKeychain and kSecUseKeychain on either SecKeyCreateWithData() or SecItemAdd() changes anything. I also tried PKCS12 despite that it always expects an "identity" (key + cert), while I only have (and need) a private key. Exporting as formatPKCS12 and importing it with itemTypeAggregate (or itemTypeUnknown) does import the key, and now it's only missing the kSecAttrApplicationTag as the original label is automatically included in the PKCS12. The outItems parameter contains an empty list though, which sort of makes sense because I'm not importing a full "identity". I can at least target the key by kSecAttrLabel for SecItemUpdate(), but any attempt to update the comment once again changes the label so it's not really any better than before. SecPKCS12Import() doesn't even import anything at all, even though it does return errSecSuccess while also passing kSecImportExportKeychain explicitly. Is there literally no way?

We're experiencing crashes in our production iOS app related to Apple's DeviceCheck framework. The crash occurs in DCAnalytics internal performance tracking, affecting some specific versions of iOS 18 (18.4.1, 18.5.0). Crash Signature CoreFoundation: -[__NSDictionaryM setObject:forKeyedSubscript:] + 460 DeviceCheck: -[DCAnalytics sendPerformanceForCategory:eventType:] + 236 Observed Patterns Scenario 1 - Token Generation: Crashed: com.appQueue EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000000000010 DeviceCheck: -[DCDevice generateTokenWithCompletionHandler:] Thread: Background dispatch queue Scenario 2 - Support Check: Crashed: com.apple.main-thread EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000000000008 DeviceCheck: -[DCDevice _isSupportedReturningError:] DeviceCheck: -[DCDevice isSupported] Thread: Main thread Root Cause Analysis The DCAnalytics component within DeviceCheck attempts to insert a nil value into an NSMutableDictionary when recording performance metrics, indicating missing nil validation before dictionary operations. Reproduction Context Crashes occur during standard DeviceCheck API usage: Calling DCDevice.isSupported property Calling DCDevice.generateToken(completionHandler:) (triggered by Firebase App Check SDK) Both operations invoke internal analytics that fail with nil insertion attempts. Concurrency Considerations We've implemented sequential access guards around DeviceCheck token generation to prevent race conditions, yet crashes persist. This suggests the issue likely originates within the DeviceCheck framework's internal implementation rather than concurrent access from our application code. Note: Scenario 2 occurs through Firebase SDK's App Check integration, which internally uses DeviceCheck for attestation. Request Can Apple engineering confirm if this is a known issue with DeviceCheck's analytics subsystem? Is there a recommended workaround to disable DCAnalytics or ensure thread-safe DeviceCheck API usage? Any guidance on preventing these crashes would be appreciated.

Hi all, I’m building a password manager app for iOS. The app implements an ASCredentialProviderExtension and has the entitlement com.apple.developer.authentication-services.autofill-credential-provider. From a UX perspective, I’d like to help users enable my app under: Settings → General → AutoFill & Passwords What I’ve observed: Calling UIApplication.openSettingsURLString only opens my app’s own Settings page, not the AutoFill list. Some apps (e.g. Google Authenticator) appear to redirect users directly into the AutoFill Passwords & Passkeys screen when you tap “Enable AutoFill.” 1Password goes even further: when you tap “Enable” in 1Password App, it shows a system pop-up, prompts for Face ID, and then enables 1Password as the AutoFill provider without the user ever leaving the app. Questions: Is there a public API or entitlement that allows apps to deep-link users directly to the AutoFill Passwords & Passkeys screen? Is there a supported API to programmatically request that my app be enabled as an AutoFill provider (similar to what 1Password seems to achieve)? If not, what is the recommended approach for guiding users through this flow? Thanks in advance!

Hi, After enabling the new Enhanced Security capability in Xcode 26, I’m seeing install failures on devices running < iOS 26. Deployment target: iOS 15.0 Capability: Enhanced Security (added via Signing & Capabilities tab) Building to iOS 18 device error - Unable to Install ...Please ensure sure that your app is signed by a valid provisioning profile. It works fine on iOS 26 devices. I’d like to confirm Apple’s intent here: Is this capability formally supported only on iOS 26 and later, and therefore incompatible with earlier OS versions? Or should older systems ignore the entitlement, meaning this behavior might be a bug?

QuickLookAR shares the actual USDZ model instead of the original website URL — critical copyright and data leak issue on iOS 26 Since iOS 26, QuickLookAR (or ARQuickLookPreviewItem) no longer preserves the original web URL when sharing a model. Instead of sending the link to the hosted file, the system directly shares the actual USDZ model file with the recipient. This is a critical regression and a severe breach of intellectual property protection, as it exposes proprietary 3D models that must never be distributed outside of the controlled web environment. In earlier iOS versions (tested up to iOS 18), QuickLookAR correctly handled sharing — the share sheet would send the website link where the model is hosted, not the file itself. Starting with iOS 26, this behavior has changed and completely breaks the intended secure flow for AR experiences. Our project relies on allowing users to view models in AR via QuickLook, without ever transferring the underlying 3D assets. Now, the share operation forces full file sharing, giving end users unrestricted access to the model file, which can be copied, rehosted, or reverse-engineered. This issue critically affects production environments and prevents us from deploying our AR-based solutions. Implement a standard QuickLookAR preview with a USDZ file hosted on your web server (e.g., via ARQuickLookPreviewItem). 2. Open the AR view on iOS 26. 3. Tap the Share icon from QuickLookAR. 4. Send via any messenger (Telegram, WhatsApp, etc.). 5. Observe that the actual .usdz model is sent instead of the original website URL. ⸻ Expected behavior: QuickLookAR should share only the original URL (as in iOS 17–18), not the file itself. This ensures that intellectual property and licensed 3D models remain protected and controlled by the content owner. ⸻ Actual behavior: QuickLookAR shares the entire USDZ file, leaking the model content outside of the intended environment. ⸻ Impact: • Violation of copyright and confidential data policies • Loss of control over proprietary 3D assets • Breaking change for all existing web-based AR integrations • Critical blocker for AR production deployment ⸻ Environment: • iOS 26.0 and 26.1 (tested on iPhone 14, iPhone 15) • Safari + QuickLookAR integration • Works correctly on iOS 17 / iOS 18 ⸻ Notes: This regression appears to have been introduced in the latest iOS 26 system handling of QuickLookAR sharing. Please escalate this issue to the ARKit / QuickLook engineering team as it directly affects compliance, IP protection, and usability of AR features across production applications. Additional Notes / Verification: Please test this behavior yourself using the CheckAR test model on my website: https://admixreality.com/ios26/ • If the login page appears, click “Check AR” and then “View in Your Space”. • On iOS 18 and earlier, sharing correctly sends the website URL. • On iOS 26, sharing sends the actual USDZ model file. This clearly demonstrates the regression and the security/IP issue.

Hi! Is it possible to disable the option for users to 'Sign in with Another Device'? I encounter this message during the authentication process and I want to prevent it from appearing. I appreciate your help and look forward to your response.

Hello everyone, In my application, i have implemented authentication using ASWebauthenticationSession. However, when redirecting the user to a WKWebView, no cookies are shared, causing the session to be lost and requiring the user to log in again. Is there a way to share cookies between the two? If not, what would be the best approach to set up authentication that ensures SSO when switching to a WebView ? Thank you very much for your help !

From watching the video on App Attest the answer would appear to be no, but the video is a few years old so in hope, I thought I would post this question anyway. There's several scenarios where I would like a notification service extension to be able to use App Attest in communications with the back end(for example to send a receipt to the backend acknowledging receipt of the push, fetching an image from a url in the push payload, a few others). Any change App Attest can be used in by a notification service extension?

Hello Team, We’ve recently started receiving reports from our customer base (Trellix) regarding issues with Full Disk Access (FDA) for Trellix binaries on macOS devices running Tahoe 26.1 (released on November 3, 2025). The issue occurs when users attempt to add Trellix CLI binaries under FDA to grant the required permissions; the binaries fail to appear under the FDA settings, even after selection. Upon further investigation, this appears to be a macOS 26.1–specific issue and not observed in earlier versions. Similar reports have been noted across various forums, indicating that the issue affects multiple binaries, not just Trellix: Some of the discussions on the same issue I see online. https://developer.apple.com/forums/thread/806187 https://developer.apple.com/forums/thread/806156 https://forum.logik.tv/t/macos-26-1-installation-issue-wait-before-updating/13761 https://www.reddit.com/r/MacOS/comments/1os1ph3/cant_add_anything_to_privacy_security_full_disk/ I have also logged FB21009024 for the same. We would like to understand when we can expect this to be fixed, since the issue persists even in 26.2 Beta and also whether the workaround of dragging and dropping the binaries can still be suggested?

Hi everyone, I'm currently working on a native macOS app (built with SwiftUI) and I'm trying to implement Password AutoFill functionality so users can use their saved credentials from Keychain or third-party password managers. I've gone through Apple's documentation, WWDC sessions, and sample code, but I've noticed that the resources primarily focus on iOS and web implementations. There's very limited guidance specifically for macOS. I've set up: Associated Domains entitlement with the webcredentials: service The apple-app-site-association file on my server TextField with .textContentType(.username) and SecureField with .textContentType(.password) However, I'm still not seeing the expected AutoFill behavior on macOS like I would on iOS. Has anyone successfully implemented Password AutoFill on a native macOS app? Are there any macOS-specific considerations or additional steps required that differ from iOS? Any guidance, sample code, or pointers to documentation I might have missed would be greatly appreciated.

When an app is trying to access identities put in the keychain by cryptotokenkit extension, the user gets asked a permission pop-up which reads 'Token Access Request" would like access a token provided by: " with 2 options 'Don't allow' and 'OK' I accidently clicked "Don't allow" and now can't access identities put in crypto token kit. How can I reset the preference?

Why can’t sandboxed mac app store apps have full disk access available in the system settings for full disk access? I discovered mac app store apps in release mode cannot access the ai auggie command line program and other command line programs like opengrep on your system. Debug builds fine. I came up with a workaround: Since I have an ssh client built in for connecting to remote servers, why not connect to ssh on the same local machine… Ask the user for their username and password in a popup. To do this, you have to enable remote login on your mac in system settings -> sharing. In addition you must grant full disk access to cli ssh in system settings: add /usr/libexec/sshd-keygen-wrapper It all works, but I don’t see the cli program in mac settings. To remove the cli program you must run a command line program to remove all full disk access support from all apps. No way to just undo ssh. So my question is, even though I got CodeFrog all working for a mac app store release, should I not do it because it’s insecure or too complicated with the system settings? Should I instead sell the app off the store like Panic Nova? Need some advice. I have not implemented in app purchases yet. Should I just have a reality check and sell the app off the store, or try for app store approval? Bummer… Maybe I’m ahead of my time, but perhaps Apple could review the source code for apps requesting full disk access and make sure there’s nothing fraudulent in them. Then, developer tools app store apps could be in the store with the user’s assurance that nothing is happening behind the scenes that is scary. From: https://blog.greenrobot.com/2025/11/10/i-have-a-decision-to-make/ Related post: https://developer.apple.com/forums/thread/806187 I submitted a code level tech support question for this. They directed me here.

Hello, Thanks for the new video on Memory Integrity Enforcement! Is the presented app's sample code available (so that we can play with it and find & fix the bug on our own, using Soft Mode)? Thanks in advance!

Hi, We are using the MSAL library to authenticate users, with SSO authentication implemented through the Microsoft Authenticator app. The problem is that once or twice a day, a prompt for forced authentication appears, indicating that silent token acquisition is failing and resulting in a requirement for forced authentication. Below are some of the logs: ================================================= 2025-08-28 11:00:05.034 [Info] [AppDelegate.swift:121] application(:didFinishLaunchingWithOptions:) > MSAL message: TID=751353 MSAL 1.8.1 iOS 18.5 [2025-08-28 10:00:05 - EC9D1457-2D70-4878-926F-553391EBC9D3] [MSAL] Silent flow finished. Result (null), error: -51115 error domain: MSIDErrorDomain 2025-08-28 11:00:05.034 [Info] [AppDelegate.swift:121] application(:didFinishLaunchingWithOptions:) > MSAL message: TID=751353 MSAL 1.8.1 iOS 18.5 [2025-08-28 10:00:05 - EC9D1457-2D70-4878-926F-553391EBC9D3] [MSAL] acquireTokenSilent returning with error: (MSALErrorDomain, -50002) Masked(not-null) ==================================================== We initially raised this issue with Microsoft, but according to them: In the app's logs, the single one failure it contains, was when the SSO extension returned the error com.apple.AuthenticationServices.AuthorizationError, -6000 during a silent call. This error code is generated by the system framework (Apple), not by our code. It indicates that the framework encountered an unexpected internal issue before or after calling the SSO extension. MSAL returning interaction_required to the client app is the most effective way to recover from this error (as you mention, after the user selects the account the app continues working as expected). Additionally, as you also mention, the interactive call is made by switching to Authenticator (not displaying a "window" without leaving Eva Lite app), which means MSAL is not able to use the SSO extension and is using the fallback to legacy authentication. The recommended next step is for the customer to request support directly from Apple as this is an issue on their side. Additionally, the customer can also try to update to the latest iOS, in case Apple has already fixed this issue. ============================================= STEPS TO REPRODUCE There is no such steps its just that this is an enterprise application which is getting used on managed devices[iPhone 14]. The device are managed using some intune policy. Platform and Version: iOS Development Environment: Xcode 15, macOS 13.6.1 Run-time Configuration: iOS 18 Please let me know if there are any solutions to resolve this problem. Thank you.

Hello everyone, I'm working on a project where I intend to use Secure Enclave-based, device-bound private keys within a Webauthn flow. I have the following question: Is it possible to generate private keys in the Secure Enclave with integrated attestation in order to reliably prove to a relying party the authenticity and uncompromised state of the key? If so, I would appreciate details on the implementation—specifically, any prerequisites, limitations, or particular API calls and configuration options that need to be considered. I look forward to any advice, best practices, or pointers to further documentation on this topic. Thank you in advance for your support! Best regards, Alex

Dear Apple Developer Support, We are currently encountering a recurring issue with the DeviceCheck API across multiple devices in our production environment. The following error is frequently returned: com.apple.devicecheck.error 0 We would like to ask the following: What are the possible underlying causes that could lead to this specific error code (0) in the DeviceCheck API? Is there any known behavior or condition where Wi-Fi network configurations (e.g., DNS filtering, proxy settings, captive portals) could result in this error? Are there known timeouts, connectivity expectations, or TLS-level requirements that the DeviceCheck API enforces which could fail silently under certain network conditions? Is this error ever triggered locally (e.g., client library-level issues) or is it always from a failed communication with Apple’s servers? Any technical clarification, documentation, or internal insight into this error code would be greatly appreciated. This would help us significantly narrow down root causes and better support our users