Apple Technotes (Unofficial) TN3213: Moving from Multipeer Connectivity to Network framework https://developer.apple.com/documentation/technotes/tn3213-moving-from-multipeer-connectivity-to-network-framework 2026-07-22T00:00:16.288282T12:00:00.000Z
Learn how to migrate your Multipeer Connectivity app to Network framework.
 TN3210: Optimizing your app for iPhone Mirroring https://developer.apple.com/documentation/technotes/tn3210-optimizing-your-app-for-iphone-mirroring 2026-06-08T19:00:40.575755T12:00:00.000Z
Test your app and improve compatibility with iPhone Mirroring.
 TN3211: Resolving SwiftUI source incompatibilities for State and ContentBuilder https://developer.apple.com/documentation/technotes/tn3211-resolving-swiftui-source-incompatibilities-for-state-and-contentbuilder 2026-06-08T19:00:40.575691T12:00:00.000Z
Update existing code for two foundational changes in SwiftUI built with Xcode 27.
 TN3212: Adopting gesture recognizers for Sidecar touch support https://developer.apple.com/documentation/technotes/tn3212-adopting-gesture-recognizers-for-sidecar-touch-support 2026-06-08T19:00:40.575644T12:00:00.000Z
Use gesture recognizers to handle Sidecar touch input and update your event-handling code for macOS 27.
 TN3208: Preparing your app’s launch screen to meet App Store requirements https://developer.apple.com/documentation/technotes/tn3208-preparing-your-apps-launch-screen-to-meet-app-store-requirements 2026-06-08T19:00:40.575608T12:00:00.000Z
Understand the launch screen requirement for App Store submission starting in iOS 27 and iPadOS 27.
 TN3205: Low-latency communication with RDMA over Thunderbolt https://developer.apple.com/documentation/technotes/tn3205-low-latency-communication-with-rdma-over-thunderbolt 2026-03-19T16:01:07.037175T12:00:00.000Z
Learn how to use RDMA over Thunderbolt to enable low-latency communication between clusters of Mac computers.
 TN3206: Updating Apple Pay certificates https://developer.apple.com/documentation/technotes/tn3206-updating-apple-pay-certificates 2026-03-12T15:01:28.019748T12:00:00.000Z
Learn how to create, manage, and rotate Apple Pay certificates to maintain uninterrupted payment processing.
 TN3190: USB audio device design considerations https://developer.apple.com/documentation/technotes/tn3190-usb-audio-device-design-considerations 2025-10-07T14:00:00.958270T12:00:00.000Z
Learn the best techniques for designing devices that conform to the USB Audio Device Class specifications.
 TN3193: Managing the on-device foundation model’s context window https://developer.apple.com/documentation/technotes/tn3193-managing-the-on-device-foundation-model-s-context-window 2025-10-06T20:00:01.159221T12:00:00.000Z
Learn how to budget for the context window limit of Apple’s on-device foundation model and handle the error when reaching the limit.
 TN3194: Handling account deletions and revoking tokens for Sign in with Apple https://developer.apple.com/documentation/technotes/tn3194-handling-account-deletions-and-revoking-tokens-for-sign-in-with-apple 2025-10-03T18:00:01.063110T12:00:00.000Z
Learn the best techniques for managing Sign in with Apple user sessions and responding to account deletion requests.
 TN3192: Migrating your iPad app from the deprecated UIRequiresFullScreen key https://developer.apple.com/documentation/technotes/tn3192-migrating-your-app-from-the-deprecated-uirequiresfullscreen-key 2025-09-08T21:00:00.740020T12:00:00.000Z
Support iPad multitasking and dynamic resizing while updating your app to remove the deprecated full-screen compatibility mode.
 TN3191: IMAP extensions supported by Mail for iOS, iPadOS, and visionOS https://developer.apple.com/documentation/technotes/tn3191-imap-extensions-supported-by-mail 2025-08-27T18:00:01.242005T12:00:00.000Z
Learn which extensions to the RFC 3501 IMAP protocol are supported by Mail for iOS, iPadOS, and visionOS.
 TN3189: Managing Mail background traffic load https://developer.apple.com/documentation/technotes/tn3189-managing-mail-background-traffic-load 2025-05-09T14:00:00.845500T12:00:00.000Z
Identify iOS Mail background traffic and manage its impact on your IMAP server.
 TN3187: Migrating to the UIKit scene-based life cycle https://developer.apple.com/documentation/technotes/tn3187-migrating-to-the-uikit-scene-based-life-cycle 2025-05-05T17:00:00.913158T12:00:00.000Z
Update your app to receive scene-based life-cycle events and manage your user interface using scene objects and methods.
 TN3186: Troubleshooting In-App Purchases availability in the sandbox https://developer.apple.com/documentation/technotes/tn3186-troubleshooting-in-app-purchases-availability-in-the-sandbox 2025-04-29T20:00:00.562791T12:00:00.000Z
Identify common configurations that make your In-App Purchases unavailable in the sandbox environment.
 TN3185: Troubleshooting In-App Purchases availability in Xcode https://developer.apple.com/documentation/technotes/tn3185-troubleshooting-in-app-purchases-availability-in-xcode 2025-04-29T20:00:00.562732T12:00:00.000Z
Inspect your active StoreKit configuration file for unexpected configurations.
 TN3188: Troubleshooting In-App Purchases availability in the App Store https://developer.apple.com/documentation/technotes/tn3188-troubleshooting-in-app-purchases-availability-in-the-app-store 2025-04-29T20:00:00.562463T12:00:00.000Z
Verify your In-App Purchases are approved and available for sale in the App Store.
 TN3183: Adding required reason API entries to your privacy manifest https://developer.apple.com/documentation/technotes/tn3183-adding-required-reason-api-entries-to-your-privacy-manifest 2024-12-17T13:00:01.028082T12:00:00.000Z
Declare the APIs that can potentially fingerprint devices in your app or third-party SDK in a privacy manifest.
 TN3184: Adding data collection details to your privacy manifest https://developer.apple.com/documentation/technotes/tn3184-adding-data-collection-details-to-your-privacy-manifest 2024-12-17T13:00:01.027837T12:00:00.000Z
Declare the data your app or third-party SDK collects in a privacy manifest.
 TN3182: Adding privacy tracking keys to your privacy manifest https://developer.apple.com/documentation/technotes/tn3182-adding-privacy-tracking-keys-to-your-privacy-manifest 2024-12-17T13:00:01.027695T12:00:00.000Z
Declare the tracking domains you use in your app or third-party SDK in a privacy manifest.
 TN3180: Reverting to App Store Server Notifications V1 https://developer.apple.com/documentation/technotes/tn3180-reverting-app-store-server-notifications-v1 2024-11-12T13:00:00.837621T12:00:00.000Z
Migrate from version 2 to version 1 of App Store Server Notifications using the Modify an App endpoint.
 TN3181: Debugging an invalid privacy manifest https://developer.apple.com/documentation/technotes/tn3181-debugging-invalid-privacy-manifest 2024-11-12T13:00:00.837562T12:00:00.000Z
Identify common configurations that cause unsuccessful privacy manifest validation with the App Store.
 TN3179: Understanding local network privacy https://developer.apple.com/documentation/technotes/tn3179-understanding-local-network-privacy 2024-10-31T14:00:00.571276T12:00:00.000Z
Learn how local network privacy affects your software.
 TN3178: Checking for and resolving build UUID problems https://developer.apple.com/documentation/technotes/tn3178-checking-for-and-resolving-build-uuid-problems 2024-10-08T14:00:00.786167T12:00:00.000Z
Ensure that every Mach-O image has a UUID, and that every distinct Mach-O image has its own unique UUID.
 TN3177: Understanding alternate audio track groups in movie files https://developer.apple.com/documentation/technotes/tn3177-understanding-alternate-audio-track-groups-in-movie-files 2024-09-26T23:00:00.773342T12:00:00.000Z
Learn how alternate groups collect audio tracks, and how to choose which audio track to use in your app.
 TN3176: Troubleshooting Apple Pay payment processing issues https://developer.apple.com/documentation/technotes/tn3176-troubleshooting-apple-pay-payment-processing-issues 2024-06-25T15:00:01.036339T12:00:00.000Z
Diagnose errors that occur when processing Apple Pay payments, identify common causes, and explore potential solutions.
 TN3175: Diagnosing issues with displaying the Apple Pay button on your website https://developer.apple.com/documentation/technotes/tn3175-diagnosing-issues-with-displaying-the-apple-pay-button-on-your-website 2024-06-25T15:00:01.036261T12:00:00.000Z
Diagnose common errors received while displaying the Apple Pay button on your website by identifying the underlying causes, and explore potential solutions.
 TN3174: Diagnosing issues with the Apple Pay payment sheet on your website https://developer.apple.com/documentation/technotes/tn3174-diagnosing-issues-with-the-apple-pay-payment-sheet-on-your-website 2024-06-25T14:00:00.970162T12:00:00.000Z
Diagnose errors received while presenting the Apple Pay payment sheet on your website by identifying the underlying causes of common errors and explore their potential solutions.
 TN3156: Create rich previews for Messages https://developer.apple.com/documentation/technotes/tn3156-create-rich-previews-for-messages 2024-06-11T15:00:00.923652T12:00:00.000Z
Learn best practices for creating rich text and image previews for display in the Messages app.
 TN3173: Troubleshooting issues with your Apple Pay merchant identifier configuration https://developer.apple.com/documentation/technotes/tn3173-troubleshooting-issues-with-your-apple-pay-merchant-id-configuration 2024-06-11T15:00:00.923599T12:00:00.000Z
Diagnose errors due to invalid Apple Pay merchant identifier configurations by identifying the underlying causes of common errors and explore their potential solutions.
 TN3168: Making your App Clip available in the App Store https://developer.apple.com/documentation/technotes/tn3168-making-your-app-clip-available-app-store 2024-06-04T15:00:00.934174T12:00:00.000Z
Learn how to configure your App Clip to prevent it from being unavailable in the App Store.
 TN3124: Debugging coordinate space issues https://developer.apple.com/documentation/technotes/tn3124-debugging-coordinate-transformations 2024-03-26T14:00:01.038737T12:00:00.000Z
Learn techniques to help debug any coordinate space issue.
 TN3165: Packet Filter is not API https://developer.apple.com/documentation/technotes/tn3165-packet-filter-is-not-api 2024-02-28T18:00:00.727704T12:00:00.000Z
Plan your migration from Packet Filter to Network Extension.
 TN3158: Resolving Xcode 15 device connection issues https://developer.apple.com/documentation/technotes/tn3158-resolving-xcode-15-device-connection-issues 2024-02-28T18:00:00.727525T12:00:00.000Z
Identify software preventing Xcode 15 from connecting to Apple devices, and modify your configuration to allow these connections.
 TN3162: Understanding CloudKit throttles https://developer.apple.com/documentation/technotes/tn3162-understanding-cloudkit-throttles 2024-02-20T12:00:00.709855T12:00:00.000Z
Learn how to identify and handle CloudKit throttles.
 TN3164: Debugging the synchronization of NSPersistentCloudKitContainer https://developer.apple.com/documentation/technotes/tn3164-debugging-the-synchronization-of-nspersistentcloudkitcontainer 2024-02-20T12:00:00.709640T12:00:00.000Z
Identify and resolve synchronization issues when working with NSPersistentCloudKitContainer.
 TN3163: Understanding the synchronization of NSPersistentCloudKitContainer https://developer.apple.com/documentation/technotes/tn3163-understanding-the-synchronization-of-nspersistentcloudkitcontainer 2024-02-20T12:00:00.709551T12:00:00.000Z
Explore the details inside the synchronization of NSPersistentCloudKitContainer by capturing and analyzing a sysdiagnose.
 TN3161: Inside Code Signing: Certificates https://developer.apple.com/documentation/technotes/tn3161-inside-code-signing-certificates 2024-02-06T12:00:00.665262T12:00:00.000Z
Learn how code signing uses certificates to identify code authors.
 TN3159: Migrating Sign in with Apple users for an app transfer https://developer.apple.com/documentation/technotes/tn3159-migrating-sign-in-with-apple-users-for-an-app-transfer 2024-01-09T16:00:00.791260T12:00:00.000Z
Migrate existing Sign in with Apple user identifiers and private email relay addresses by exchanging transfer identifiers from one developer team to another with the user migration info endpoint.
 TN3157: Updating your watchOS project for SwiftUI and WidgetKit https://developer.apple.com/documentation/technotes/tn3157-updating-your-watchos-project-for-swiftui-and-widgetkit 2023-11-07T15:00:01.013841T12:00:00.000Z
Update your watchOS app project to adopt SwiftUI, WidgetKit, and other modern features.
 TN3155: Debugging universal links https://developer.apple.com/documentation/technotes/tn3155-debugging-universal-links 2023-09-06T03:00:01.788745T12:00:00.000Z
Investigate why your universal links are opening in a web browser instead of your app.
 TN3154: Adopting SwiftUI navigation split view https://developer.apple.com/documentation/technotes/tn3154-adopting-swiftui-navigation-split-view 2023-08-29T19:00:01.038532T12:00:00.000Z
Use navigation split view to enable two and three column navigation in your SwiftUI app while maintaining compatibility with earlier OS versions.
 TN3151: Choosing the right networking API https://developer.apple.com/documentation/technotes/tn3151-choosing-the-right-networking-api 2023-06-06T13:00:01.000886T12:00:00.000Z
Learn which networking API is best for you.
 TN3152: Migrating to the latest Calendar access levels https://developer.apple.com/documentation/technotes/tn3152-migrating-to-the-latest-calendar-access-levels 2023-06-06T13:00:01.000787T12:00:00.000Z
Follow these guidelines to update your app to use the new Calendar access levels.
 TN3153: Adopting API changes for EventKit in iOS 17, macOS 14, and watchOS 10 https://developer.apple.com/documentation/technotes/tn3153-adopting-api-changes-for-eventkit-in-ios-macos-and-watchos 2023-06-06T13:00:01.000757T12:00:00.000Z
Test your existing apps against EventKit API latest changes.
 TN3149: Fetching Contacts change history events https://developer.apple.com/documentation/technotes/tn3149-fetching-change-history-events 2023-06-06T13:00:01.000724T12:00:00.000Z
Learn how to fetch and process the most recent changes to the Contacts database.
 TN3138: Handling App Store receipt signing certificate changes https://developer.apple.com/documentation/technotes/tn3138-handling-app-store-receipt-signing-certificate-changes 2023-05-26T14:00:00.932526T12:00:00.000Z
Ensure that your app’s local receipt validation is compatible with intermediate certificates that require using the SHA-256 algorithm.
 TN3150: Getting ready for dataless files https://developer.apple.com/documentation/technotes/tn3150-getting-ready-for-data-less-files 2023-05-10T00:00:01.163410T12:00:00.000Z
Understand dataless files and how to minimize the performance impact as the system materializes them.
 TN3147: Migrating to the latest notarization tool https://developer.apple.com/documentation/technotes/tn3147-migrating-to-the-latest-notarization-tool 2023-04-12T01:17:40.463191T12:00:00.000Z
Migrate your notarization workflows to notarytool from the deprecated altool.
 TN3145: HDR video metadata https://developer.apple.com/documentation/technotes/tn3145-hdr-video-metadata 2023-03-08T13:00:00.676797T12:00:00.000Z
Learn about the usage and requirements of “Ambient Viewing Environment” metadata with HLG and / or Dolby Vision™ Profile 8.4 playback.
 TN3136: AVAudioConverter - performing sample rate conversions https://developer.apple.com/documentation/technotes/tn3136-avaudioconverter-performing-sample-rate-conversions 2023-01-11T15:00:00.823810T12:00:00.000Z
Use AVAudioConverter to perform sample rate conversions between PCM audio buffers.
 TN3133: Packaging a Metal renderer https://developer.apple.com/documentation/technotes/tn3133-packaging-a-renderer 2022-11-09T01:00:01.345905T12:00:00.000Z
Distribute a Metal renderer in a Swift package.
 TN3137: On Mac keychain APIs and implementations https://developer.apple.com/documentation/technotes/tn3137-on-mac-keychains 2022-11-03T11:00:00.871646T12:00:00.000Z
Learn how the keychain on macOS differs from other Apple platforms.
 TN3135: Low-level networking on watchOS https://developer.apple.com/documentation/technotes/tn3135-low-level-networking-on-watchos 2022-09-27T14:00:01.039193T12:00:00.000Z
Learn about the supported use cases for low-level networking on watchOS.
 TN3128: Starting SharePlay without an existing FaceTime call https://developer.apple.com/documentation/technotes/tn3128-starting-shareplay-without-an-existing-facetime-call 2022-09-20T15:00:00.971190T12:00:00.000Z
Use the share sheet or group activity sharing controller to start SharePlay directly from your app without an existing FaceTime call.
 TN3134: Network Extension provider deployment https://developer.apple.com/documentation/technotes/tn3134-network-extension-provider-deployment 2022-09-06T20:00:00.844616T12:00:00.000Z
Explore the platforms, packaging, OS versions, and device configurations for Network Extension provider deployment.
 TN3132: Changes to EventKit and EventKitUI in iOS 16 https://developer.apple.com/documentation/technotes/tn3132-changes-eventkit-and-eventkitui-in-ios16 2022-08-16T23:06:16.238117T12:00:00.000Z
Test your apps against EventKit and EventKitUI API changes in iOS 16.
 TN3130: Changes to EventKit in macOS Ventura 13 https://developer.apple.com/documentation/technotes/tn3130-changes-to-eventkit-in-macos13-ventura 2022-08-16T23:06:16.237987T12:00:00.000Z
Test your apps against EventKit API changes in macOS Ventura 13.
 TN3129: Resolving build errors from helper tools in Xcode Cloud and other build environments https://developer.apple.com/documentation/technotes/tn3129-resolving-build-errors-from-helper-tools-in-xcode-cloud 2022-07-19T23:06:16.238042T12:00:00.000Z
Review common causes for failing Xcode Cloud builds that originate from helper tools running in a misconfigured build environment.
 TN3125: Inside Code Signing: Provisioning Profiles https://developer.apple.com/documentation/technotes/tn3125-inside-code-signing-provisioning-profiles 2022-05-03T23:06:16.238096T12:00:00.000Z
Learn how provisioning profiles enable third-party code to run on Apple platforms.
 TN3126: Inside Code Signing: Hashes https://developer.apple.com/documentation/technotes/tn3126-inside-code-signing-hashes 2022-05-03T23:06:16.238087T12:00:00.000Z
Look inside a code signature to see how it uses hashes to protect the code’s executable pages, resources, and metadata from tampering.
 TN3127: Inside Code Signing: Requirements https://developer.apple.com/documentation/technotes/tn3127-inside-code-signing-requirements 2022-05-03T23:06:16.238051T12:00:00.000Z
Explore how macOS uses code signing requirements to reason about code identity.
 TN3122: Receipt validation with the App Store fails with a non-zero error code https://developer.apple.com/documentation/technotes/tn3122-receipt-validation-with-the-app-store-fails-with-a-non-zero-error-code 2022-04-26T23:06:16.238046T12:00:00.000Z
Identify common configurations that cause unsuccessful receipt validation with the App Store.
 TN3121: Selecting a pixel format for an AVCaptureVideoDataOutput https://developer.apple.com/documentation/technotes/tn3121-selecting-a-pixel-format-for-an-avcapturevideodataoutput 2022-03-29T23:06:16.238074T12:00:00.000Z
Learn how to choose the best output pixel format for your app.
 TN3123: Refactoring your storyboard https://developer.apple.com/documentation/technotes/tn3123-refactoring-your-storyboard 2022-03-29T23:06:16.238033T12:00:00.000Z
Learn strategies and techniques for refactoring a single storyboard into multiple storyboards.
 TN3120: Expected use cases for Network Extension packet tunnel providers https://developer.apple.com/documentation/technotes/tn3120-expected-use-cases-for-network-extension-packet-tunnel-providers 2022-03-22T23:06:16.238056T12:00:00.000Z
Learn the expected use cases for Network Extension packet tunnel providers, and about use cases that are not supported.
 TN3106: Customizing the appearance of UINavigationBar https://developer.apple.com/documentation/technotes/tn3106-customizing-uinavigationbar-appearance 2022-03-01T23:06:16.238111T12:00:00.000Z
Adopt UINavigationBarAppearance for a navigation bar background color that’s consistent on iOS 13 through 18.
 TN3105: Customizing the UIKit status bar style https://developer.apple.com/documentation/technotes/tn3105-customizing-uistatusbar-syle 2022-03-01T23:06:16.238091T12:00:00.000Z
Configure the device’s status bar style to work well with your app’s user interface.
 TN3118: Debugging your app’s launch screen https://developer.apple.com/documentation/technotes/tn3118-debugging-your-apps-launch-screen 2022-03-01T23:06:16.238037T12:00:00.000Z
Understand why your app’s launch screen is not displayed or updated.
 TN3117: Resolving architecture build errors on Apple silicon https://developer.apple.com/documentation/technotes/tn3117-resolving-build-errors-for-apple-silicon 2022-02-22T23:06:16.238023T12:00:00.000Z
Update your app’s architecture build settings to support building macOS, iOS, watchOS, and tvOS apps on Apple silicon.
 TN3107: Resolving Sign in with Apple response errors https://developer.apple.com/documentation/technotes/tn3107-resolving-sign-in-with-apple-response-errors 2022-02-15T23:06:16.238017T12:00:00.000Z
Diagnose errors received by the Sign in with Apple client, or its server infrastructure, by identifying the underlying causes of common error codes and explore their potential solutions.
 TN3113: Testing and debugging XPC code with an anonymous listener https://developer.apple.com/documentation/technotes/tn3113-testing-xpc-code-with-an-anonymous-listener 2022-02-08T23:06:16.238121T12:00:00.000Z
Use an anonymous XPC listener to simplify your XPC testing and debugging.
 TN3103: Apple Pay on the Web troubleshooting guide https://developer.apple.com/documentation/technotes/tn3103-apple-pay-on-the-web-troubleshooting-guide 2022-02-08T23:06:16.238105T12:00:00.000Z
Troubleshooting guide for implementing Apple Pay on the Web.
 TN3108: Viewing the interface of your Swift code https://developer.apple.com/documentation/technotes/tn3108-viewing-the-interface-of-your-swift-code 2022-02-08T23:06:16.238100T12:00:00.000Z
Learn how to navigate to the interface file of a Swift implementation file.
 TN3110: Resolving generic Xcode archive issue https://developer.apple.com/documentation/technotes/tn3110-resolving-generic-xcode-archive-issue 2022-02-08T23:06:16.238082T12:00:00.000Z
Identify common configurations that cause a generic Xcode archive.
 TN3102: HTTP/3 in your app https://developer.apple.com/documentation/technotes/tn3102-http3-in-your-app 2022-02-08T23:06:16.238078T12:00:00.000Z
Get started with iOS 15’s new HTTP/3 support.
 TN3109: Resolving common archiving issues https://developer.apple.com/documentation/technotes/tn3109-resolving-common-archiving-issues 2022-02-08T23:06:16.238069T12:00:00.000Z
Handle common issues that arise while archiving apps.
 TN3104: Recording video in Apple ProRes https://developer.apple.com/documentation/technotes/tn3104-recording-video-in-apple-prores 2022-02-08T23:06:16.238064T12:00:00.000Z
Configure pieces of an AVCaptureSession to capture video in Apple ProRes.
 TN3111: iOS Wi-Fi API overview https://developer.apple.com/documentation/technotes/tn3111-ios-wifi-api-overview 2022-02-08T23:06:16.238028T12:00:00.000Z
Explore the various Wi-Fi APIs available on iOS and their expected use cases.
 TN3115: Bluetooth State Restoration app relaunch rules https://developer.apple.com/documentation/technotes/tn3115-bluetooth-state-restoration-app-relaunch-rules 2022-02-08T23:06:16.238010T12:00:00.000Z
Learn about the conditions under which an iOS app will be relaunched by Bluetooth State Restoration.