Background Assets

RSS for tag

Schedule background downloads of large assets during app installation, when the app updates, and periodically while the app remains on-device.

Posts under Background Assets tag

35 Posts

Post

Replies

Boosts

Views

Activity

Apple-Hosted Asset Pack Support in App Review
Does the App Review process have access to Apple-Hosted Asset Packs during review? My app uses Asset Packs to offer a library of data to the end-user (with a workaround, if unavailable), but I am frequently seeing the workaround screen in App Review with errors I haven't seen elsewhere. The latest error I encountered (via the App Review team's feedback) was: "A server with the specified hostname could not be found." thrown from (to my belief) AssetPackManager.shared.ensureLocalAvailability. This is unexpected to me, as both this code as well as the asset packs have already been released and are working reliably in production. Has anyone else experienced these issues?
0
0
36
23h
Background Assets: Second and subsequent download cancellations fail (iOS 26.0–26.3 RC)
Summary I'm using Background Assets to download Apple-hosted Asset Packs(downloadPolicy = onDemand). The first download cancellation succeeds, but on the second and subsequent downloads, progress.cancel() fails to work and the download completes to the end. Environment iOS 26.0 – 26.3 RC (all produce the same result) Xcode Version 26.2 (17C52) Using Apple-hosted Asset Packs Steps to Reproduce Start downloading an Asset Pack Call progress.cancel() during download → Succeeds Start downloading the same Asset Pack again Call progress.cancel() during download → Fails (download completes to the end) Observed Error Logs After 1st cancellation: A download with the ID "X-XXXXXXXX-XXX" failed: Error Domain=NSURLErrorDomain Code=-999 "cancelled" ↑ This is expected (cancellation succeeded) The fact that version 0 of the asset pack with the ID "X-XXXXXX-XXX" finished being downloaded couldn't be reported: Error Domain=NSCocoaErrorDomain Code=3851 "Property list invalid for format: 200 (property lists cannot contain objects of type 'CFError')" ↑ Problem: Unable to serialize CFError to plist 2nd cancellation attempt: The download with the ID "X-XXXXXX-XXX" couldn't be canceled: Error Domain=BAErrorDomain Code=113 "The requested download operation failed because the download object did not exist." ↑ The download object we're trying to cancel supposedly doesn't exist Implementation Code // Cancel implementation func cancel(tag: String) async { let statusUpdates = AssetPackManager.shared.statusUpdates(forAssetPackWithID: tag) for await statusUpdate in statusUpdates { if case .downloading(_, let progress) = statusUpdate, progress.isCancellable { progress.cancel() } } } Analysis It appears that when the first cancellation occurs, the system internally tries to save the cancellation state to a plist, but fails to serialize the CFError object. This seems to cause an inconsistent internal state, preventing the system from correctly recognizing the download object on subsequent downloads. Questions Is there a workaround? Is there a planned fix for a future iOS version?
1
0
64
4d
Archiving Asset Pack for App B caused archive for App A Asset Pack
Hello, I've just been unfortunate enough to discover a critical issue. I have two apps using Asset Packs, and I believe both apps had an Asset Pack with the same identifier. In App Store Connect for App B, I archived this Asset Pack. However, the Asset Pack has been archived for both Apps. This shouldn't happen.
2
0
140
1w
Read, Write, and Consuming Files / URLs
Hello, I have an asset pack that I'm use to periodically distribute a sqlite database thats being used to an NSPersistentStore. Because the database is over a few GBs, and the files in an AssetPack are not mutable, I have to stream the database into a temporary file, then replace my NSPersistentStore. This requires that the user has 3x the storage available of the database, and permanently uses twice to storage needed. I'd like: To be able to mark a URL/File to be accessible for read/write access To be able to mark a file / URL as consumed when it's no needed. So that it can be cleared from the user storage while still maintaining an active subscription to the asset pack for updates. Thank you
4
0
219
1w
Asset Pack Limit
I have a total of 100 asset packs associated with my app but I have archived 5 of them. Unfortunately I am now unable to upload any more asset packs (the reported error is "backgroundAsset limit reached -- This app has already reached the maximum number of active backgroundAssets. Maximum allowed is 100.") I assumed that archiving asset packs would make them inactive (and thus not count against the limit). This seems to not be the case and I'm not sure how I can upload new asset packs.
4
0
202
2w
Listing files of a background asset
Is there a way to enumerate all files within a folder of an asset pack or just all files in general? My application is using the Apple demo code to load a file from an Apple hosted asset pack: let descriptor = try AssetPackManager.shared.descriptor(for: "NAV/NavData.db3") defer { try descriptor.close() } if let path = path(for: descriptor) { self.database = try Database(path: path) } As my "Navigation Data" is updated each month with an updated asset pack I would like to have the name of the .db3 file reflect the current data cycle (e.g. NAV2601.db3, NAV2602.db3, ...) Ideally I would like to iterate over all files within the NAV folder of the current asset pack and pick the most recent one. Unfortunately, neither the AssetPackManager nor the AssetPack object seem to include an API for this. It would be cool to have something like: let files = try AssetPackManager.shared.files(for: "NAV/") for file in files { //Check and load }
3
0
367
3w
Essential Background Assets prevent immediate installation feedback
Hello, I have an app with a few essential asset packs currently totaling to ~8GB. I've noticed that when trying to install the app fresh from TestFlight, there is a significant delay between tapping install and the app appearing on the device in the loading state. The delay is long enough where it's hard to tell what's happening, or if the installation has failed. This also appears to be an issue in App Review, as I've had my app rejected twice due to the app not loading on the reviewers device. The reason they gave is UIRequiredDeviceCapabilities is blocking the installation, but UIRequiredDeviceCapabilities is empty. Note: I'm not looking for App Store review help, simply sharing the extent of the issue. Thank you
2
0
258
3w
TestFlight Call To Action With Essential Download
Hello, I was just installing an app from TestFlight that has an Essential Asset Pack that's a few GBs in size. It appears the Call To Action inside of TestFlight doesn't take into consideration the Background Asset download status before it changes from Installing to Open. I can't test if this is also the case for apps on the App Store, but I'd expect that it is.
3
1
330
3w
ITMS-90555: On-Demand Resources exceed 30GB after App Thinning – Need clarification on variant size calculation
Hello, I am encountering the following error when uploading a build to App Store Connect: ITMS-90555: Thinned app size is too large – Your on-demand resources in the universal variant are 30 GB, which exceeds the maximum allowable size. After app thinning, the total size of your on-demand resource asset packs in any variant must be less than 30 GB. Our application includes a large amount of font resources delivered via ODR. Before making structural changes, I need clarification because the documentation does not fully explain how ODR size calculations work per variant. Environment Xcode: (latest stable) Distribution method: App Store submission ODR total size before thinning: approximately (28 GB) Build processing fails immediately with the ITMS-90555 error Questions How exactly does App Thinning compute the size of ODR asset packs per variant? Is ODR size evaluated: Per device-specific variant, Or is the “universal variant” treated as an additional variant that must independently stay under 30GB? The documentation mentions a 30GB limit per variant, but the universal variant error message is ambiguous. If device-specific variants are below 30GB but only the “universal variant” exceeds it, is the build still rejected? In our case: iPhone-only variants appear to be below the limit, But the universal variant exceeds 30GB due to aggregated resources. Is this expected behavior? Best practices for managing very large ODR sets (e.g., fonts) Fonts are small individually, but thousands of them produce very large ODR groups. Is there recommended guidance from Apple for: Structuring ODR bundles to avoid the universal variant exceeding the limit Segmenting ODR by device class / feature sets Any alternative packaging strategies Are there tools or logs that reveal how App Store Connect decides variant groupings and ODR size? At the moment, the failure only shows the ITMS-90555 error without further detail. Case-ID for DTS reference DTS advised submitting this question here. Case-ID: 17273913 Any clarification from Apple engineers or community members who have navigated ODR size limits would be greatly appreciated. Thank you very much!
2
0
237
Jan ’26
Can not re-upload an Asset Pack that's been archived?
Hello, I'm trying to upload an asset pack that has the same identifier as an asset pack that I've archived. I understand this isn't likely a common scenario, but I'd expect that uploading an archived Asset Pack to become un-archived. Reverting to the next newest version available for the Asset Pack. Further, this restriction is not clear that you won't be able to reuse the assetPackID on the archive asset pack alert Archive Asset Pack? Are you sure you want to archive "[NAME]" asset pack? All versions of this asset will no longer be accessible by your app. Errors: Failed to create a new background asset pack version for '[NAME]'. (-19243) operation not allowed (409) Cannot create version for an archived background asset. (ID: 2cc6499a-83fa-4bbb-bc1f-0bb67d2a873d) httpBody: { "errors" : [ { "id" : "2cc6499a-83fa-4bbb-bc1f-0bb67d2a873d", "status" : "409", "code" : "STATE_ERROR.ARCHIVED_BACKGROUND_ASSET", "title" : "operation not allowed", "detail" : "Cannot create version for an archived background asset." } ]
3
0
290
Dec ’25
Are Assets Packs actually downloaded in the background?
Hello, I have a question about when are asset packs actually updated? For Essential Asset Packs, this only during the keys included in the pack? As in, only when the app is installed for firstInstallation. And only when there's an app update for subsequentUpdate? For On Demand Asset Packs, is this only when AssetPackManager.shared.checkForUpdates() is called? Also, are any asset packs ever actually updated in the background? For example, if an On Demand Asset Pack has an update pushed, can the device automatically fetch and download the pack overnight? Or is updating limited to only when the app is active?
2
0
217
Dec ’25
Can multiple Apps in the same App Group share Asset Packs?
Hello, I have an Asset Pack that's a database. I need to use it in 2 apps. I'm curious at the expected functionality of cross app Asset Pack distribution as I've seen conflicting behavior. (1) Each app is required to have its own unique Background Assets Target. (2) Uploading the asset pack requires the App ID to be included. (3) I'm able to access the Asset Pack of App #1 inside of App #2 by using AssetPackManager.shared.ensureLocalAvailability(of:) with local testing (Not TestFlight) This is a technical question as originally I planned to duplicate the upload of the Asset Pack to both individual apps.
1
0
101
Dec ’25
Background Assets testing in Xcode
Can anyone please confirm that Apple-hosted Background Assets still will NOT work unless the app is: Installed from TestFlight, or Installed from the App Store Is it true Xcode-installed builds—Debug or Release—do not receive the App Store’s Background Asset metadata and cannot access the background asset packs? I am getting the error when running the app in Xcode: The asset pack with the ID “VALIDPACKNAME” couldn’t be looked up: No asset pack with the ID “VALIDPACKNAME” was found.
1
0
143
Dec ’25
Some questions about how to use the Background Assets capability on iOS
Regarding the Background Assets capability on iOS: In the install scenario, resources defined as the "install" type are incorporated into the App Store download progress. Do resources of the "update" type in the update scenario also get incorporated into the App Store download progress in the same way? If an exception occurs during the download of install-type resources and the download cannot proceed further, will the system no longer actively block users from launching the app and instead enable the launch button? Currently, if a user has enabled automatic updates on their device, after the app is updated and released on the App Store, will the Background Assets download start immediately once the automatic update completes? Or does Background Assets have its own built-in scheduling logic that prevents it from running concurrently with the automatic update?
1
0
125
Dec ’25
Persistent font registration crashes when fonts are delivered via Apple-Hosted Background Assets
Hi everyone, I’m trying to register fonts system-wide using CTFontManagerRegisterFontURLs with the .persistent scope. The fonts are delivered through Apple-Hosted Background Assets (since On-Demand Resources are deprecated). Process-level registration works perfectly, but persistent registration triggers a system “Install Fonts” prompt, and tapping Install causes the app to crash immediately. I’m wondering if anyone has successfully used Apple-Hosted Background Assets to provide persistent, system-wide installable fonts, or if this is a current OS limitation/bug. What I Expect Fonts delivered through Apple-Hosted Background Assets should be eligible for system-wide installation Tap “Install” should install fonts into Settings → Fonts just like app-bundled or ODR fonts App should not crash Why This Matters According to: WWDC 2019: Font Management and Text Scaling Developers can build font provider apps that install fonts system-wide, using bundled or On-Demand Resources. WWDC 2025: Discover Apple-Hosted Background Assets On-Demand Resources are deprecated, and AHBAs are the modern replacement. Therefore, persistent font installation via Apple-Hosted Background Assets appears to be the intended path moving forward. Question Is this a known limitation or bug in iOS? Should .persistent font installation work with Apple-Hosted Background Assets? Do we need additional entitlement, manifest configuration, or packaging rules? Any guidance or confirmation from Apple engineers would be greatly appreciated. Additional Info I submitted a Feedback including a minimal reproducible sample project: FB21109320
3
0
275
Nov ’25
Apple-hosted managed asset pack not found on macOS
Hi all, I have set up a trivial test project to try Apple-hosted background assets following the instructions in the three articles at https://developer.apple.com/documentation/backgroundassets. When I run the local mock server with xcrun ba-serve and set the URL override in Settings as described in the "Testing asset packs locally" article, I am able to download a test pack on my iOS devices. On the Mac that I use to run the mock server, however, the same call to AssetPackManager.shared.assetPack(withID: "TestAssetPack") that works on iOS always reports The asset pack with the ID “TestAssetPack” couldn’t be looked up: No asset pack with the ID “TestAssetPack” was found. even when not running the mock server, which led me to believe that it may not be hitting it at all. In fact, the macOS app will download asset packs uploaded to App Store Connect even when running the local server and setting the xcrun ba-serve url-override to the exact same string as in Settings on iOS. My initial suspicion was that something is wrong with the URL override, so I have tried all combinations of the Mac's hostname, IP address or "localhost" (with the corresponding SSL certificates) with and without port 443, always prefixing with "https://" for the url-override. All the same. Does anyone have an idea what may be the issue here? My asset pack has the following manifest: { "assetPackID": "TestAssetPack", "downloadPolicy": { "onDemand": {} }, "fileSelectors": [ { "file": "TestAsset.txt" } ], "platforms": [ "iOS", "macOS" ] } I am running v26.1 for macOS, iOS & Xcode. Edit: Just to be clear, my assumption here is that the URL overrides (in Settings on iOS or via ba-serve on macOS) is what should cause the app to hit the mock server. Is that correct or am I missing something?
11
0
456
Nov ’25
On Demand Resources as Legacy Technology
I read on this documentation : https://developer.apple.com/help/app-store-connect/reference/app-uploads/on-demand-resources-size-limits that On Demand Resources a legacy technology. Does this mean ODR will be deprecated? If so, when will it officially take effect? Our application is planning to use it, so we need more information to support our decision.
1
0
172
Nov ’25
How are Assets removed?
Hello, I'm trying to figure out the behavior of AssetPackManager.shared.remove(assetPackWithID: ). I'm working with MapKit tiles and currently working on trying projecting them correctly which involves serving the AssetPack locally, downloading, checking alignment, and then deleting and changing. My question is that remove(assetPackWithID: ) completes successfully and the asset pack is removed. This is confirmed by trying to remove the AssetPack again which throws an error. However, the asset is still appearing on MapKit after the removal. This is a bit odd as this persists not only with force killing, but also restarting the device. Please advise on how to properly remove an AssetPack. Thank you iPhone 15 Pro Max (iOS 26.0.1) iPhone 17 Pro Max (iOS 26.0.1)
6
1
423
Nov ’25
Background Assets - Apple Hosted - iOS26
I've followed the setup process to get Apple Hosted Background Assets configured for my project. (https://developer.apple.com/documentation/backgroundassets/downloading-apple-hosted-asset-packs) But when I build and run the app I get the following error... BackgroundAssets/AssetPackManager.swift:174: Fatal error: The process lacks a team ID. I've checked the Signing->Team for both targets and they both have my Team associated. Any help or advice would be appreciated...
7
0
544
Nov ’25