Hi, I'm stuck distributing a custom FoundationModels adapter as an Apple-hosted managed asset pack via TestFlight. Everything looks correctly configured end to end but the download just never starts and the statusUpdates sequence is silent. Here's my configuration: App Info.plist: <key>BAHasManagedAssetPacks</key><true/> <key>BAUsesAppleHosting</key><true/> <key>BAAppGroupID</key><string>group.com.fiuto.shared</string> Entitlement com.apple.developer.foundation-model-adapter on both the app and the asset downloader extension. The asset downloader extension uses StoreDownloaderExtension , returning SystemLanguageModel.Adapter.isCompatible(assetPack) from shouldDownload , and the app group on app and asset download extension is the same. I have exported the adapter with toolkit 26.0.0, obtaining: adapterIdentifier = fmadapter-FiutoAdapter-1234567 I have packaged the asset pack using xcrun ba-package and uploaded it to App Store Connect via Transporter, and I get the "ready for internal and external testing" state on App Store Connect, and I have uploaded my app build on TestFlight after the asset pack was marked as ready. I used this code: let adapter = try SystemLanguageModel.Adapter(name: "FiutoAdapter") let ids = SystemLanguageModel.Adapter.compatibleAdapterIdentifiers(name: "FiutoAdapter") // ids == ["fmadapter-FiutoAdapter-1234567"] for await status in AssetPackManager.shared.statusUpdates(forAssetPackWithID: ids.first!) { } I expect the download to start and the stream to yield first .began, then .downloading(progress) and .finished. Actually, compatibleAdapterIdentifiers returns the correct ID, the stream is correctly acquired but i get zero events, so no .began/.downloading/.failed/.finished. Important things: I don't get any error in Console as well; I tested this as an internal tester on TestFlight Tested on iPhone 16 Pro, running iOS 26.3.1 - more than 50GB of free space Apple Intelligence is enabled and set in Italian Background downloads are enabled. I've already checked if the adapter identifier matches regex fmadapter-\w+-\w+ , i tried to reinstall the build, rebooting the device, reupload the asset pack, and also checked that the foundation models adapter entitlement is present on both targets. Is there a known way to diagnose why statusUpdates is silent (no log subsystem seems to show why) in this exact configuration? Is there maybe any delay between asset pack approval on App Store Connect and availability to TestFlight internal testers that I do not know of? I've checked other threads for applicable solutions and I've found that this is similar to the symptom reported in this thread: https://developer.apple.com/forums/thread/805140 / (FB20865802) and also i'm internal tester and on stable iOS 26.3.1, so the limitations from this thread: https://developer.apple.com/forums/thread/793565 shouldn't apply. Thanks

I have an iOS app, "Spatial Agents" which ran great in 26.3. It creates dashboards around a topic. It can also decompose a topic into sub-topics, and explore those. All based on web articles and web article headlines. In iOS 26.4 almost every topic - even "MIT Innovation" are rejected with an apology of "I apologize I can not fulfill this request". I've tried softening all my prompts, and I can get only really benign very simple topics to respond, but not anything with any significance. It ran great on lots of topics in 26.3. My published App, is now useless, and all my users are unhappy. HELP!

Hi, I'm trying to add FoundationModels to an older project but always get the following error: "Unable to resolve 'dependency' 'FoundationModels' import FoundationModels" The error comes and goes while its compiling and then doesn't run the app. I have my target set to 26.0 (and can't go any higher) and am using Xcode 26 (17E192). Is anyone else having this issue? Thanks, Dan Uff

Hello! After the 26.4 update I get a huge number of LanguageModelSession.GenerationError.refusal errors when using guided generation Generables for inexplicable reasons. Such errors also occur, if I want to cast a response to boolean by using 'generating: Bool.self'. The explanation generated on the grounds of the error always looks like this: Response(userPrompt: "", duration: 0.230917542, promptTokenCount: Optional(66), responseTokenCount: Optional(11), feedbackAttachment: nil, content: "I apologize, but I cannot fulfill this request.", rawContent: "I apologize, but I cannot fulfill this request.", transcriptEntries: ArraySlice([])) All the prompts and Generables I use are definitely not profane. Before 26.4 such errors on the same prompts and Generables never occurred. The 26.4 update rendered those features unusable to me. Is this a known bug or what am I doing wrong?

After installing iOS 26.4 the Foundation Models instruction following and tool calling capabilities have been degraded significantly. The model is not usable anymore. Examples: This works: "Is the car plugged in?" This does not work: "Tell me if the car is plugged in" Anything with the work "frunk" (front trunk) triggers Guardrail Violation. Phrases like "Lock Pride" also trigger Guardrail Violation (Pride is the name of the car). Tool calling only works half the time for really obvious things.

I keep getting the error “An unsupported language or locale was used.” Is there any documentation that specifies the accepted languages or locales in Foundation model?

We get two error message in Xcode debug. apple.model.catalog we get 1 time at startup, and the nw_protocol_instance_set_output_handler Not calling remove_input_handler on 0x152ac3c00:udp we get on sartup and some time during running of the app. I have tested cutoff repos WS eg. But nothing helpss, thats for the nw_protocol. We have a fondationmodel in a repo but we check if it is available if not we do not touch it. Please help me? nw_protocol_instance_set_output_handler Not calling remove_input_handler on 0x152ac3c00:udp com.apple.modelcatalog.catalog sync: connection error during call: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.modelcatalog.catalog was invalidated: Connection init failed at lookup with error 159 - Sandbox restriction." UserInfo={NSDebugDescription=The connection to service named com.apple.modelcatalog.catalog was invalidated: Connection init failed at lookup with error 159 - Sandbox restriction.} reached max num connection attempts: 1 The function we have in the repo is this: public actor FoundationRepo: JobDescriptionChecker, SubskillSuggester { private var session: LanguageModelSession? private let isEnabled: Bool private let shouldUseLocalFoundation: Bool private let baseURLString = "https://xx.xx.xxx/xx" private let http: HTTPPac public init(http: HTTPPac, isEnabled: Bool = true) { self.http = http self.isEnabled = isEnabled self.session = nil guard isEnabled else { self.shouldUseLocalFoundation = false return } let model = SystemLanguageModel.default guard model.supportsLocale() else { self.shouldUseLocalFoundation = false return } switch model.availability { case .available: self.shouldUseLocalFoundation = true case .unavailable(.deviceNotEligible), .unavailable(.appleIntelligenceNotEnabled), .unavailable(.modelNotReady): self.shouldUseLocalFoundation = false @unknown default: self.shouldUseLocalFoundation = false } } So here we decide if we are going to use iPhone ML or my backend-remote?

When doing some exploratory research into using Apple Intelligence in our aviation-focused application, I noticed that there were several times that key phases would be marked as inappropriate. I tried to stifle these using prompts and rules but couldn't get it to take hold. I was encouraged by an Apple employee to go ahead and post this so that the AI team can use the feedback. There were several terms that triggered this warning, but the two that were most prominent were: 'Tailwind' 'JFK' or 'KJFK' (NY airport ICAO/IATA codes)

Recursive and Self-Referential Data Structures Combining recursive and self-referential data structures with frameworks like Accelerate, SwiftMacros, and utilizing SwiftUI hooks can offer significant benefits in terms of performance, maintainability, and expressiveness. Here is how Apple Intelligence breaks it down. Benefits: Natural Representation of Complex Data: Recursive structures, such as trees and graphs, are ideal for representing hierarchical or interconnected data, like file systems, social networks, and DOM trees. Simplified Algorithms: Many algorithms, such as traversals, sorting, and searching, are more straightforward and elegant when implemented using recursion. Dynamic Memory Management: Self-referential structures can dynamically grow and shrink, making them suitable for applications with unpredictable data sizes. Challenges: Performance Overhead: Recursive algorithms can lead to stack overflow if not properly optimized (e.g., using tail recursion). Self-referential structures can introduce memory management challenges, such as retain cycles. Accelerate Framework Benefits: High-Performance Computation: Accelerate provides optimized libraries for numerical and scientific computing, including linear algebra, FFT, and image processing. It can significantly speed up computations, especially for large datasets, by leveraging multi-core processors and GPU acceleration. Parallel Processing: Accelerate automatically parallelizes operations, making it easier to take advantage of modern hardware capabilities. Integration with Recursive Data: Matrix and Vector Operations: Use Accelerate for operations on matrices and vectors, which are common in recursive algorithms like those used in machine learning and physics simulations. FFT and Convolutions: Accelerate's FFT functions can be used in recursive algorithms for signal processing and image analysis. SwiftMacros Benefits: Code Generation and Transformation: SwiftMacros allow you to generate and transform code at compile time, enabling the creation of DSLs, boilerplate reduction, and optimization. Improved Compile-Time Checks: Macros can perform complex compile-time checks, ensuring code correctness and reducing runtime errors. Integration with Recursive Data: DSL for Data Structures: Create a DSL using SwiftMacros to define recursive data structures concisely and safely. Optimization: Use macros to generate optimized code for recursive algorithms, such as memoization or iterative transformations. SwiftUI Hooks Benefits: State Management: Hooks like @State, @Binding, and @Effect simplify state management in SwiftUI, making it easier to handle dynamic data. Side Effects: @Effect allows you to perform side effects in a declarative manner, integrating seamlessly with asynchronous operations. Reusable Logic: Custom hooks enable the reuse of stateful logic across multiple views, promoting code maintainability. Integration with Recursive Data: Dynamic Data Binding: Use SwiftUI's data binding to manage the state of recursive data structures, ensuring that UI updates reflect changes in the underlying data. Efficient Rendering: SwiftUI's diffing algorithm efficiently updates the UI only for the parts of the recursive structure that have changed, improving performance. Asynchronous Data Loading: Combine @Effect with recursive data structures to fetch and process data asynchronously, such as loading a tree structure from a remote server. Example: Combining All Components Imagine you're building an app that visualizes a hierarchical file system using a recursive tree structure. Here's how you might combine these components: Define the Recursive Data Structure: Use SwiftMacros to create a DSL for defining tree nodes. @macro struct TreeNode { var value: T var children: [TreeNode] } Optimize with Accelerate: Use Accelerate for operations like computing the size of the tree or performing transformations on node values. func computeTreeSize(_ node: TreeNode) -> Int { return node.children.reduce(1) { $0 + computeTreeSize($1) } } Manage State with SwiftUI Hooks: Use SwiftUI hooks to load and display the tree structure dynamically. struct FileSystemView: View { @State private var rootNode: TreeNode = loadTree() var body: some View { TreeView(node: rootNode) } private func loadTree() -> TreeNode<String> { // Load or generate the tree structure } } struct TreeView: View { let node: TreeNode var body: some View { List(node.children, id: \.value) { Text($0.value) TreeView(node: $0) } } } Perform Side Effects with @Effect: Use @Effect to fetch data asynchronously and update the tree structure. struct FileSystemView: View { @State private var rootNode: TreeNode = TreeNode(value: "/") @Effect private var loadTreeEffect: () -> Void = { // Fetch data from a server or database } var body: some View { TreeView(node: rootNode) .onAppear { loadTreeEffect() } } } By combining recursive data structures with Accelerate, SwiftMacros, and SwiftUI hooks, you can create powerful, efficient, and maintainable applications that handle complex data with ease.

Reading all the docs(1) I was under the impression that handling this error is well managed... Until I hit it and found out that the recommended handling options hide a crucial fact: in the catch block you can not do anything?! It's too late - everything is lost, no way to recover... All the docs mislead me that I can apply the Transcript trick in the catch block until I realised, that there is nothing there !!! This article here(2) enlightened me on the handling of this problem, but I must say (and the author as well) - this is a hack! So my questions: is there really no way to handle this exception properly? if not, can we have the most important information - the count of the context exposed through the official API (at least the known ones)? https://developer.apple.com/documentation/Technotes/tn3193-managing-the-on-device-foundation-model-s-context-window#Handle-the-exceeding-context-window-size-error-elegantly https://zats.io/blog/making-the-most-of-apple-foundation-models-context-window/

The deployment target for my app was set to iOS 18.1 originally, but now that I'm using Foundational Models framework, it has been set to iOS 26.0. Is this ok?

I am trying to test FoundationModels in a Swift Playground in Xcode 26.2, macOS 26.3, and am running into an issue. The following simple code generates an error: import FoundationModels @Generable struct Specifications { @Guide(description: "Search for color") var color: String } I see the following error message in the console: error: AIPlayground.playground:4:8: external macro implementation type 'FoundationModelsMacros.GenerableMacro' could not be found for macro 'Generable(description:)'; plugin for module 'FoundationModelsMacros' not found The Xcode editor does not appear to recognize the @Generable or @Guide macros, despite importing FoundationModels. What step/setting am I missing?

I have been able to train an adapter on Google's Colaboratory. I am able to start a LanguageModelSession and load it with my adapter. The problem is that after one simple prompt, the context window is 90% full. If I start the session without the adapter, the same simple prompt consumes only 1% of the context window. Has anyone encountered this? I asked Claude AI and it seems to think that my training script needs adjusting. Grok on the other hand is (wrongly, I tried) convinced that I just need to tweak some parameters of LanguageModelSession or SystemLanguageModel. Thanks for any tips.

A foundation models bug I keep running into when in the preview phase of the testing. The error never seems to occur or break the app when I am testing on the simulator or on a device but sometimes I am running into this error when in a longer session while being in preview. The error breaks the preview and crashes it and the waring on it is labeled as : "Assert in LanguageModelFeedback.swift" This is something I keep running into, where I have been using foundation models for my project

Hi, I am a new IOS developer, trying to learn to integrate the Apple Foundation Model. my set up is: Mac M1 Pro MacOS 26 Beta Version 26.0 beta 3 Apple Intelligence &amp; Siri --&gt; On here is the code, func generate() { Task { isGenerating = true output = "⏳ Thinking..." do { let session = LanguageModelSession( instructions: """ Extract time from a message. Example Q: Golfing at 6PM A: 6PM """) let response = try await session.respond(to: "Go to gym at 7PM") output = response.content } catch { output = "❌ Error:, \(error)" print(output) } isGenerating = false } and I get these errors guardrailViolation(FoundationModels.LanguageModelSession.GenerationError.Context(debugDescription: "Prompt may contain sensitive or unsafe content", underlyingErrors: [Asset com.apple.gm.safety_embedding_deny.all not found in Model Catalog])) Can you help me get through this?

Hi, I am developing an iOS application that utilizes Apple’s Foundation Models to perform certain summarization tasks. I would like to understand whether user data is transferred to Private Cloud Compute (PCC) in cases where the computation cannot be performed entirely on-device. This information is critical for our internal security and compliance reviews. I would appreciate your clarification on this matter. Thank you.

Greetings! I was trying to get a response from the LanguageModelSession but I just keep getting the following: Error getting response: Model Catalog error: Error Domain=com.apple.UnifiedAssetFramework Code=5000 "There are no underlying assets (neither atomic instance nor asset roots) for consistency token for asset set com.apple.MobileAsset.UAF.FM.Overrides" UserInfo={NSLocalizedFailureReason=There are no underlying assets (neither atomic instance nor asset roots) for consistency token for asset set com.apple.MobileAsset.UAF.FM.Overrides} This occurs both in macOS 15.5 running the new Xcode beta with an iOS 26 simulator, and also on a macOS 26 with Xcode beta. The simulators are both Pro iPhone 16s. I was wondering if anyone had any advice?

I'm experimenting with Foundation Models and I'm trying to understand how to define a Tool whose input argument is defined at runtime. Specifically, I want a Tool that takes a single String parameter that can only take certain values defined at runtime. I think my question is basically the same as this one: https://developer.apple.com/forums/thread/793471 However, the answer provided by the engineer doesn't actually demonstrate how to create the GenerationSchema. Trying to piece things together from the documentation that the engineer linked to, I came up with this: let citiesDefinedAtRuntime = ["London", "New York", "Paris"] let citySchema = DynamicGenerationSchema( name: "CityList", properties: [ DynamicGenerationSchema.Property( name: "city", schema: DynamicGenerationSchema( name: "city", anyOf: citiesDefinedAtRuntime ) ) ] ) let generationSchema = try GenerationSchema(root: citySchema, dependencies: []) let tools = [CityInfo(parameters: generationSchema)] let session = LanguageModelSession(tools: tools, instructions: "...") With the CityInfo Tool defined like this: struct CityInfo: Tool { let name: String = "getCityInfo" let description: String = "Get information about a city." let parameters: GenerationSchema func call(arguments: GeneratedContent) throws -> String { let cityName = try arguments.value(String.self, forProperty: "city") print("Requested info about \(cityName)") let cityInfo = getCityInfo(for: cityName) return cityInfo } func getCityInfo(for city: String) -> String { // some backend that provides the info } } This compiles and usually seems to work. However, sometimes the model will try to request info about a city that is not in citiesDefinedAtRuntime. For example, if I prompt the model with "I want to travel to Tokyo in Japan, can you tell me about this city?", the model will try to request info about Tokyo, even though this is not in the citiesDefinedAtRuntime array. My understanding is that this should not be possible – constrained generation should only allow the LLM to generate an input argument from the list of cities defined in the schema. Am I missing something here or overcomplicating things? What's the correct way to make sure the LLM can only call a Tool with an input parameter from a set of possible values defined at runtime? Many thanks!

I've created the following Foundation Models Tool, which uses the .anyOf guide to constrain the LLM's generation of suitable input arguments. When calling the tool, the model is only allowed to request one of a fixed set of sections, as defined in the sections array. struct SectionReader: Tool { let article: Article let sections: [String] let name: String = "readSection" let description: String = "Read a specific section from the article." var parameters: GenerationSchema { GenerationSchema( type: GeneratedContent.self, properties: [ GenerationSchema.Property( name: "section", description: "The article section to access.", type: String.self, guides: [.anyOf(sections)] ) ] ) } func call(arguments: GeneratedContent) async throws -> String { let requestedSectionName = try arguments.value(String.self, forProperty: "section") ... } } However, I have found that the model will sometimes call the tool with invalid (but plausible) section names, meaning that .anyOf is not actually doing its job (i.e. requestedSectionName is sometimes not a member of sections). The documentation for the .anyOf guide says, "Enforces that the string be one of the provided values." Is this a bug or have I made a mistake somewhere? Many thanks for any help you provide!

I’d like to submit a feature request regarding the availability of Foundation Models in MessageFilter extensions. Background MessageFilter extensions play a critical role in protecting users from spam, phishing, and unwanted messages. With the introduction of Foundation Models and Apple Intelligence, Apple has provided powerful on-device natural language understanding capabilities that are highly aligned with the goals of MessageFilter. However, Foundation Models are currently unavailable in MessageFilter extensions. Why Foundation Models Are a Great Fit for MessageFilter Message filtering is fundamentally a natural language classification problem. Foundation Models would significantly improve: Detection of phishing and scam messages Classification of promotional vs transactional content Understanding intent, tone, and semantic context beyond keyword matching Adaptation to evolving scam patterns without server-side processing All of this can be done fully on-device, preserving user privacy and aligning with Apple’s privacy-first design principles. Current Limitations Today, MessageFilter extensions are limited to relatively simple heuristics or lightweight models. This often results in: Higher false positives Lower recall for sophisticated scam messages Increased development complexity to compensate for limited NLP capabilities Request Could Apple consider one of the following: Allowing Foundation Models to be used directly within MessageFilter extensions Providing a constrained or optimized Foundation Model API specifically designed for MessageFilter Enabling a supported mechanism for MessageFilter extensions to delegate inference to the containing app using Foundation Models Even limited access (e.g. short text only, strict execution limits) would be extremely valuable. Closing Foundation Models have the potential to significantly raise the quality and effectiveness of message filtering on Apple platforms while maintaining strong privacy guarantees. Supporting them in MessageFilter extensions would be a major improvement for both developers and users. Thank you for your consideration and for continuing to invest in on-device intelligence.