I've been unable to successfully get a webpage to send a message to a Safari web extension, no matter what I try doing. I've added the following to my manifest.json file, and it's running manifest v3 { "externally_connectable": { "matches": [ "*://mywebsite.com/*", "*://localhost:3000/*" ] } } My web page executes the following code snippet. I've tried this both while running my site locally (on localhost) and pushed to production. let safariExtensionId = "co.companyname.productname.Extension (ABCD1234)" browser.runtime.sendMessage(safariExtensionId, { greeting: "hello"}, function(response) { console.log("Received response from background page"); console.log(response.farewell); } ); In the Safari web extension's background.js file, I've added the following onMessageExternal listener: browser.runtime.onMessageExternal.addListener((message, sender, sendResponse) => { console.log("Received message from the sender."); console.log(message.greeting); sendResponse({ farewell: "Goodbye!" }); }); This is directly copied from the instructions in this WWDC video: https://developer.apple.com/documentation/safariservices/messaging-between-a-webpage-and-your-safari-web-extension It's also extremely difficult to debug what's happening since the extensions service working frequently does not appear in the Web Extension Background Content menu Is there something I'm doing wrong, or a bug I'm not aware of?

Hello - we have a Mac application that uses a browser extension and the web extension JS APIs to communicate with Safari. As of macOS 15.4 / Safari 18.4 the tab OnAttached and tab onDetached events are no longer received. After some testing we verified that the events were working properly as of macOS 15.3 / Safari 18.3 but appear to have been broken in macOS 15.4. Note a similar issue was reported previously for Safari 17.6 and was fixed in macOS 15.0 (FB14324177). We have made a TestFlight version of our app (Tabby) available to simplify debugging via https://testflight.apple.com/join/Va8Zdv9d. To reproduce the issue: Install the Tabby TestFlight build on macOS 15.4 or 15.4.1 Open Safari, go to Safari settings and select the Extensions tab Enable the Tabby extension and grant permissions to all windows all the time Open a Safari window with at least 3 tabs Note the open window and tabs displayed in Tabby In Safari, perform a tab detach by dragging a tab out of the window Expected behavior Within Safari the detached tab should now be in it’s own window, and via the onDetached event Tabby should update to show the tab in it’s own window AND removed from the original window. Observed Safari fails to send the onDetached event and Tabby will continue to display the detached tab in its original window in addition to the new window. You can also use the repro steps above to observe the onDetached event being received or not by Tabby in the Safari developer console. The same steps but re-attaching the tab to the original window can be used to observe the onAttached event being received or not. We’ve attached two screen recordings to the Feedback ID below, one showing the events working on macOS 15.3, and one showing the events failing to be received on macOS 15.4.1. Note it also fails on macOS 15.4. FEEDBACK ID: FB17367977

Hi! I'm working on a web extension for Safari and I need to send messages from the containing application to JavaScript. For this I use the method class func dispatchMessage( withName messageName: String, toExtensionWithIdentifier identifier: String, userInfo: [String : Any]? = nil ) async throws of the SFSafariApplication class. If the site is opened in Safari in normal mode, everything works as expected. However, if the site is "docked", the messages are not transmitted to this "Web App". Is it possible to somehow link the container application to the docked website so that messages from the application are received by this "Web App"? That you.

We have an existing Safari App Extension distributed outside the App Store (self-distributed). Recently, we converted another browser extension to a Safari Web Extension and used the same bundle ID as the original application to avoid any change on the CX side. After distributing this updated app, we noticed that the Safari extension was disabled on users' machines, and users are now required to manually re-enable it in Safari's preferences. Is this the expected behavior and is there way to avoid this for future updates ?

When our Safari Web Extension makes a api request from its background script (registered via "scripts" in manifest.json, e.g., "background": { "scripts": ["js/background.bundle.js"] }) to our authenticated API endpoint (https://api-domain/user), the Cookie header is not included in the request. This occurs only when the extension is running within a non-default Safari User Profile. This causes our API to treat the user as unauthenticated. The exact same extension code, manifest, and API call work correctly (Cookie header is present and user is authenticated) when the extension is running in the Default Safari User Profile.

There does not appear to be any way to use or create iCloud passkeys with a Safari Web Extension, either using the navigator.credentials API in an extension origin webpage such as the popover, or using the AuthenticationServices framework in the SafariWebExtensionHandler. I've setup an associated domain for my plugin, and I know it works for the host application. But I get errors trying to do so in the web extension target. createCredentialRegistrationRequests results in the following error: Domain=com.apple.AuthenticationServices.AuthorizationError Code=1004 "Application with identifier <ID> is not associated with domain <RPID> The other problem, assuming the entitlement works correctly for the web extension, is that there is no NSWindow to use as the presentation target from the SafariWebExtensionHandler. Trying to use the navigator.credentials.create JS API (which is the preferred method, frankly, in a web extension) results in the following error: NotAllowedError: The request is not allowed by the user agent or the platform in the current context, possibly because the user denied permission. Chrome has a great solution for this that I believe should be adopted by Safari. If an extension has host permissions for a relying party it wants to claim, or if it has an associated domain entitlement for it, webauthn operations should be allowed.

updateDynamic rules is blocking ads on my device with iOS 17.4, but on my iOS 18 device the same code is not blocking ads. Is this a known issue?

Hello, According to the documentation: If you provide your extension in macOS and don’t want to use the Mac App Store for distribution, you can sign and notarize your extension’s app with a Developer ID to distribute it outside the Mac App Store. However, I found this to be untrue in practice. Even after signing and notarising the Safari extension correctly, it is not possible to enable it in Safari without turning on "allow unsigned extension". This makes it impossible to distribute your Developer ID–signed and notarized extension outside the Mac App Store. I would like to distribute my web extension directly to employees in my organization using MDM without having each user manually enable "allow unsigned extension" for it to work. Any way to make it work? The documentation is quite confusing in this aspect, it says "Safari only supports signed extensions" but my extension is rejected even if notarised and signed.

使用direct distribution进行分发时，safari web extension 在safari setting 中显示没有权限读取、修改或传输任何网页的内容。 但是我在看公证日志显示插件是正常的公证的 这导致safari extension 无法使用。 公证日志 https://www.coupert.com/img/2025-04-10/notarization-log.json

Safari Extension Error: “Non-persistent background content cannot listen to webRequest events.” after macOS 15.4 / Safari 18.4 Update We’re seeing the following error in the Safari Extensions tab after updating to macOS 15.4 and Safari 18.4: “Non-persistent background content cannot listen to webRequest events.” This error did not appear prior to the update, and we haven’t found any official documentation stating that webRequest API is no longer supported in Safari. In our extension (Manifest V3), we are using the webRequest.onHeadersReceived callback to intercept response headers and read updated cookies. While the functionality itself still works as expected. we’re able to access the response headers and this error is now shown in the Extension settings page. We are not seeing this issue in other browsers (Chrome, Firefox) using the same Manifest V3 setup. Is there any plan to deprecate webRequest support in Manifest V3 for Safari? We’d appreciate any clarification or guidance on how to handle this going forward.

I'm building a macOS Google Chrome extension. I need to be able to send messages from the Chrome extension to the macOS app What's the set up flow? I've heard about native messaging, but I struggle to implement it. I've heard about XPC, but not sure JS can send messages to a macOS XPC service.

We’re encountering an issue when trying to add non-standard headers to outgoing requests using Declarative Net Request (DNR) rules in our Safari Web Extension. Tested on macOS 15.4 with Safari 18.4. Specifically, when attempting to add a custom header such as "X-Custom-Header" using a DNR rule, the header does not appear in the request. We are able to add standard headers like "Authorization" and "Cookie" to the request successfully using the same method. This behavior suggests that Safari may be filtering or blocking non-standard headers when set via DNR rules, unlike other browsers. In Chrome and Firefox, the same rule adds the "X-Custom-Header" header without any issue. We are looking for assistance in fixing these issues and having our Safari Extension function the same as it does in Firefox and Chrome.

We’re seeing an issue in our Safari Web Extension where not all cookies from the Set-Cookie response header are accessible. We are using macOS 15.4 and Safari 18.4. In the webRequest.onHeadersReceived callback, the Set-Cookie header returned by Safari only includes some of the cookies set by the server. If multiple Set-Cookie headers are present, we seem to receive only a partial list, some cookies are missing entirely. In Chrome and Firefox, the same callback provides all cookies set by the server without issue. We are looking for assistance in fixing these issues and having our Safari Extension function the same as it does in Firefox and Chrome.

When a DNR rule is set for a specific URL and the request receives a server-side redirect (e.g., 302) to a different URL that does not match the urlFilter, the rule still seems to apply to the redirected request. We are using macOS 15.4 and Safari 18.4. For example, consider two sequential calls: call1 and call2. call1 triggers a 302 redirect to call2. A DNR rule is created to add a "Cookie" header to call1 based on its URL. Unexpectedly, the same cookie is also added to call2, even though call2's URL does not match the rule's urlFilter. This results in the Set-Cookie response from call1 being ignored, and call2 receiving the manually set cookie instead—leading to incorrect behavior. This issue doesn't occur in Chrome or Firefox, where the rule is not applied to the redirected request if the URL no longer matches. We are looking for assistance in fixing these issues and having our Safari Extension function the same as it does in Firefox and Chrome.

My Mac app and its Safari web extension share an app group, and I want to notify the web extension native process when the app makes a change to the app group NSUserDefaults, but I can't find a good way to do this. According to the documentation, "You can use key-value observing to register observers for specific keys of interest in order to be notified of all updates, regardless of whether changes are made within or outside the current process." In my testing, however, this doesn't work in the web extension process. I'm using NSUserDefaults addObserver forKeyPath, but observeValueForKeyPath never gets called. I've also tried NSDistributedNotificationCenter, but the web extension process doesn't receive the notifications sent by the main app. Are either of these supposed to work? If not, are there any alternatives?

iOS 18.4 introduces the new WKWebExtension API to support extensions in WKWebView. However, for extensions that have migrated to Manifest V3 and use an extension service worker as the background script, it's currently not possible to inspect them through Safari. This is only thing I can see, I don't know how to inspect the details of the "background.js" I'm wondering—has this changed? Is it now possible to inspect extension service workers?

This browser extension is a doc reading enhancer for the Apple Developer website. It supports i18n translation, hover link previews, and bilingual display. Currently, it supports four languages: ja-JP, ko-KR, zh-CN, and zh-TW. It works with Swift/SwiftUI/Foundation modules now, and it's expected to support Swift Test, Swift Charts, UIKit, Swift Playground, and XCode modules by the end of this month. For more info, check out: https://appledocs.dev. You can also visit https://appledocs.dev/progress to see translation progress and vote. Note: It's only works on Chrome、Edge(In review)、Firefox(In review) Screenshot:

Safari Version 14.0.1 (16610.2.11.51.8) I am porting a Chrome/Firefox/Edge extension to Safari Web Extension. Mostly, the process was painless, I am, however, seeing quite different behavior in the tab ids generated by Safari compared to Chrome, Firefox, and Edge. My extension has callbacks for each of these browser.webNavigation events: browser.webNavigation.onBeforeNavigate browser.webNavigation.onCommitted browser.webNavigation.onDOMContentLoaded In each of these I rely on the tab id for various future tab targeting operations. When opening a new tab, the details object passed to each of these callbacks has a non-zero tabId on Chrome, Firefox, and Edge. However, in Safari, the tabId is always zero. To debug, I added one more callback: browser.webNavigation.onCompleted At this point Safari finally has a non-zero tabId in the details param. Needless to say this is causing some consternation with achieving the same outcomes as tab tracking on Chrome, Firefox, and Edge. It's like Safari is treating new tabs as "non tabs" until navigation completes. You can even see it when trying to get the tab by tabId=0: browser.tabs.get(tabId) // tabId=0 here &#9;.then(tab => { &#9;&#9;// tab is undefined &#9;}); Seems like this might be a bug. I can't imagine why the behavior is so different from other browsers. Any ideas on how to work around?

I am trying to build and run a Safari Web Extension from Xcode and I have enabled "Allow unsigned extensions" in Safari settings. However, I see the below pop up: And, if click on the "Quit and Open Safari Extensions Preferences..." button, the project stops running on Xcode and nothing happens. What can be the issue? The extension works and runs fine if I get it from the Mac App Store and this only happens when running from Xcode. I even tried completely uninstalling the mac app store version and still facing the same issue.

I'm trying to load a Safari Extension onto my physical iPhone 15 running iOS 18.4 but am seeing the following message: "iOS 18.4 is not installed." When I click the Get button I see that the download has failed with the following error message. I tried updating my laptop to Sequoia and I also deleted and re-installed Xcode but that didn't fix it. Any thoughts? Download failed. Domain: DVTDownloadableErrorDomain Code: 41 User Info: { DVTErrorCreationDateKey = "2025-04-08 06:00:22 +0000"; } -- Download failed. Domain: DVTDownloadableErrorDomain Code: 41 -- Failed fetching catalog for assetType (com.apple.MobileAsset.iOSSimulatorRuntime), serverParameters ({ RequestedBuild = 22E238; }) Domain: DVTDownloadsUtilitiesErrorDomain Code: -1 -- Download failed due to a bad URL. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime) Domain: com.apple.MobileAssetError.Download Code: 49 User Info: { checkConfiguration = 1; } -- System Information macOS Version 15.4 (Build 24E248) Xcode 16.3 (23785) (Build 16E140) Timestamp: 2025-04-07T23:00:22-07:00