About technotes Technotes are focused, timely documents from Apple Developer Technical Support. They explore a wide range of development topics and provide guidance for developers creating apps and accessories for all of Apple’s platforms. Learn about specific development topics through these in-depth technical articles. You can subscribe to this RSS feed to get notified when new technotes are published. We encourage you to discuss the technotes here in the forums and share your feedback via Feedback Assistant. Let us know if a technote is helpful, or what we can do to improve it. We would appreciate it if you include a Feedback Assistant (FB) number in your forums post, so we can easily track your feedback, and let you know when it’s resolved. Tagging your post When tagging your post, please add the relevant tags for the technology area it applies to. You can also add the Technotes tag, if you wish. Providing feedback To create new feedback about a specific technote (or technotes as a whole) using Feedback Assistant, use the following path: What are you seeing an issue with? Developer Tools Which area are you seeing an issue with? Developer Documentation What does the documentation issue you are reporting involve? Technotes Please provide the URL of the content you reporting an issue with: The complete URL of the technote. For example, https://developer.apple.com/documentation/technotes/tn3102-http3-in-your-app. If you wish to leave feedback on Technotes in general, use https://developer.apple.com/documentation/technotes for the URL. Then complete the remaining fields appropriately. We appreciate and look forward to your feedback.

Understand dataless files and how to minimize the performance impact as the system materializes them. View Technote TN3150 >

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. View Technote TN3519 >

Diagnose errors that occur when processing Apple Pay payments, identify common causes, and explore potential solutions. View Technote TN3176 >

Diagnose common errors received while displaying the Apple Pay button on your website by identifying the underlying causes, and explore potential solutions. View Technote TN3175 >

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. View Technote TN3174 >

Diagnose errors due to invalid Apple Pay merchant identifier configurations by identifying the underlying causes of common errors and explore their potential solutions. View Technote TN3173 >

Learn best practices for creating rich text and image previews for display in the Messages app. View Technote TN3156 >

Learn how to configure your App Clip to prevent it from being unavailable in the App Store. View Technote TN3168 >

Learn techniques to help debug any coordinate space issue. View Technote TN3124 >

Identify and resolve synchronization issues when working with NSPersistentCloudKitContainer. View Technote TN3164 >

Explore the details inside the synchronization of NSPersistentCloudKitContainer by capturing and analyzing a sysdiagnose. View Technote TN3163 >

Learn how to identify and handle CloudKit throttles. View Technote TN3162 >

Learn how code signing uses certificates to identify code authors. View Technote TN3161 >

Explore the platforms, packaging, OS versions and device configurations for Network Extension provider deployment. View Technote TN3134 >

Learn about the usage and requirements of “Ambient Viewing Environment” metadata with Dolby Vision™ Profile 8.4 playback. View Technote TN3145 >

Use navigation split view to enable two and three column navigation in your SwiftUI app while maintaining compatibility with earlier OS versions. View Technote TN3154 >

Ensure that your app’s local receipt validation is compatible with intermediate certificates that require using the SHA-256 algorithm. View Technote TN3138 >

Investigate why your universal links are opening in Safari instead of your app. View Technote TN3155 >

Learn which networking API is best for you. View Technote TN3151 >