In 2018, Apple staff noted that Safari App Extensions had no direct API to communicate with the containing app, and suggested app groups or opening a custom URL scheme as workarounds. On iOS Safari Web Extensions, app groups work for persistence, but opening the containing app from the native extension/background flow does not appear reliable. iOS launch policy seems to require a direct user gesture, and I have not found a documented way for the extension flow to reliably continue into the containing app. Is there a supported iOS architecture for completing an extension-initiated workflow in the containing app, or is the intended model to persist data and require the user to manually open the app? My current architecture is: JavaScript in the Safari Web Extension extracts article content from the page. The native Extension Handler receives that content via native messaging. The Extension Handler writes an encoded request into the App Group container. The containing app watches the App Group container using DispatchSource.makeFileSystemObjectSource and processes new requests. This works on macOS. It also works on iOS when the containing app is already running. The problem is that on iOS, if the containing app is not already running, there is no app process to observe the filesystem event or process the request. I have tried treating the Extension Handler as the place to do more work, but in practice it seems suited only for short-lived relay/persistence work. It is not a reliable place for my app’s main processing pipeline, which includes rendering article content and uploading it to a third-party service. My app is a Safari-native “read later” style tool that uploads simplified articles to the reMarkable Cloud. The containing app contains most of the functionality: SwiftUI UI, WebKit/WebPage rendering, account/cloud logic, and upload orchestration. The Safari extension captures the article, but the app needs to run to complete the user-visible workflow. From a user’s perspective, tapping the Safari extension toolbar button is the action that initiates the workflow. Is there any supported way for that user-initiated extension action to launch or wake the containing iOS app so it can process pending App Group requests? Or should Safari Web Extensions on iOS be designed only to persist work and then ask the user to manually open the containing app? If manual app launch is the intended model, it would be helpful for the documentation to state this explicitly. The current tripartite model strongly suggests that the JavaScript extension, native handler, and containing app can collaborate as parts of one workflow, but on iOS the containing app appears to be available only out-of-band unless already running.