Hi, I'm looking for the best way to use MLX models, particularly those I've fine-tuned, within a React Native application on iOS devices. Is there a recommended integration path or specific API for bridging MLX's capabilities to React Native for deployment on iPhones and iPads?
General
RSS for tagExplore the power of machine learning within apps. Discuss integrating machine learning features, share best practices, and explore the possibilities for your app.
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Activity
During testing the “Bringing advanced speech-to-text capabilities to your app” sample app demonstrating the use of iOS 26 SpeechAnalyzer, I noticed that the language model for the English locale was presumably already downloaded. Upon checking the documentation of AssetInventory, I found out that indeed, the language model can be preinstalled on the system.
Can someone from the dev team share more info about what assets are preinstalled by the system? For example, can we safely assume that the English language model will almost certainly be already preinstalled by the OS if the phone has the English locale?
At WWDC25 we launched a new type of Lab event for the developer community - Group Labs. A Group Lab is a panel Q&A designed for a large audience of developers. Group Labs are a unique opportunity for the community to submit questions directly to a panel of Apple engineers and designers. Here are the highlights from the WWDC25 Group Lab for Machine Learning and AI Frameworks.
What are you most excited about in the Foundation Models framework?
The Foundation Models framework provides access to an on-device Large Language Model (LLM), enabling entirely on-device processing for intelligent features. This allows you to build features such as personalized search suggestions and dynamic NPC generation in games. The combination of guided generation and streaming capabilities is particularly exciting for creating delightful animations and features with reliable output. The seamless integration with SwiftUI and the new design material Liquid Glass is also a major advantage.
When should I still bring my own LLM via CoreML?
It's generally recommended to first explore Apple's built-in system models and APIs, including the Foundation Models framework, as they are highly optimized for Apple devices and cover a wide range of use cases. However, Core ML is still valuable if you need more control or choice over the specific model being deployed, such as customizing existing system models or augmenting prompts. Core ML provides the tools to get these models on-device, but you are responsible for model distribution and updates.
Should I migrate PyTorch code to MLX?
MLX is an open-source, general-purpose machine learning framework designed for Apple Silicon from the ground up. It offers a familiar API, similar to PyTorch, and supports C, C++, Python, and Swift. MLX emphasizes unified memory, a key feature of Apple Silicon hardware, which can improve performance. It's recommended to try MLX and see if its programming model and features better suit your application's needs. MLX shines when working with state-of-the-art, larger models.
Can I test Foundation Models in Xcode simulator or device?
Yes, you can use the Xcode simulator to test Foundation Models use cases. However, your Mac must be running macOS Tahoe. You can test on a physical iPhone running iOS 18 by connecting it to your Mac and running Playgrounds or live previews directly on the device.
Which on-device models will be supported? any open source models?
The Foundation Models framework currently supports Apple's first-party models only. This allows for platform-wide optimizations, improving battery life and reducing latency. While Core ML can be used to integrate open-source models, it's generally recommended to first explore the built-in system models and APIs provided by Apple, including those in the Vision, Natural Language, and Speech frameworks, as they are highly optimized for Apple devices. For frontier models, MLX can run very large models.
How often will the Foundational Model be updated? How do we test for stability when the model is updated?
The Foundation Model will be updated in sync with operating system updates. You can test your app against new model versions during the beta period by downloading the beta OS and running your app. It is highly recommended to create an "eval set" of golden prompts and responses to evaluate the performance of your features as the model changes or as you tweak your prompts. Report any unsatisfactory or satisfactory cases using Feedback Assistant.
Which on-device model/API can I use to extract text data from images such as: nutrition labels, ingredient lists, cashier receipts, etc? Thank you.
The Vision framework offers the RecognizeDocumentRequest which is specifically designed for these use cases. It not only recognizes text in images but also provides the structure of the document, such as rows in a receipt or the layout of a nutrition label. It can also identify data like phone numbers, addresses, and prices.
What is the context window for the model? What are max tokens in and max tokens out?
The context window for the Foundation Model is 4,096 tokens. The split between input and output tokens is flexible. For example, if you input 4,000 tokens, you'll have 96 tokens remaining for the output. The API takes in text, converting it to tokens under the hood. When estimating token count, a good rule of thumb is 3-4 characters per token for languages like English, and 1 character per token for languages like Japanese or Chinese. Handle potential errors gracefully by asking for shorter prompts or starting a new session if the token limit is exceeded.
Is there a rate limit for Foundation Models API that is limited by power or temperature condition on the iPhone?
Yes, there are rate limits, particularly when your app is in the background. A budget is allocated for background app usage, but exceeding it will result in rate-limiting errors. In the foreground, there is no rate limit unless the device is under heavy load (e.g., camera open, game mode). The system dynamically balances performance, battery life, and thermal conditions, which can affect the token throughput. Use appropriate quality of service settings for your tasks (e.g., background priority for background work) to help the system manage resources effectively.
Do the foundation models support languages other than English?
Yes, the on-device Foundation Model is multilingual and supports all languages supported by Apple Intelligence. To get the model to output in a specific language, prompt it with instructions indicating the user's preferred language using the locale API (e.g., "The user's preferred language is en-US"). Putting the instructions in English, but then putting the user prompt in the desired output language is a recommended practice.
Are larger server-based models available through Foundation Models?
No, the Foundation Models API currently only provides access to the on-device Large Language Model at the core of Apple Intelligence. It does not support server-side models. On-device models are preferred for privacy and for performance reasons.
Is it possible to run Retrieval-Augmented Generation (RAG) using the Foundation Models framework?
Yes, it is possible to run RAG on-device, but the Foundation Models framework does not include a built-in embedding model. You'll need to use a separate database to store vectors and implement nearest neighbor or cosine distance searches. The Natural Language framework offers simple word and sentence embeddings that can be used. Consider using a combination of Foundation Models and Core ML, using Core ML for your embedding model.
Topic:
Machine Learning & AI
SubTopic:
General
Does CoreML object detection only support AABB (Axis-Aligned Bounding Boxes) or also OBB (Oriented Bounded Boxes)? If not, any way to do it using Apple frameworks?
Topic:
Machine Learning & AI
SubTopic:
General
In WWDC25 Metal 4 released quite excited new features for machine learning optimization, but as we all know the pytorch based on metal shader performance (mps) is the one of most important tools for Mac machine learning area.but on mps introduced website we cannot see any support information for metal4.
Hey Devs,
I'm trying to create my own Real Time Text detection like this Apple project. https://developer.apple.com/documentation/vision/extracting-phone-numbers-from-text-in-images
I want to use the new iOS18 RecognizeTextRequest instead of the old VNRecognizeTextRequest in my SwiftUI project.
This is my delegate code with the camera setup. I removed region of interest for debugging but I'm trying to scan English words in books. The idea is to get one word in the ROI in the future. But I can't even get proper words so testing without ROI incase my math is wrong.
@Observable
class CameraManager: NSObject, AVCapturePhotoCaptureDelegate
...
override init() {
super.init()
setUpVisionRequest()
}
private func setUpVisionRequest() {
textRequest = RecognizeTextRequest(.revision3)
}
...
func setup() -> Bool {
captureSession.beginConfiguration()
guard
let captureDevice = AVCaptureDevice.default(
.builtInWideAngleCamera, for: .video, position: .back)
else {
return false
}
self.captureDevice = captureDevice
guard let deviceInput = try? AVCaptureDeviceInput(device: captureDevice)
else {
return false
}
/// Check whether the session can add input.
guard captureSession.canAddInput(deviceInput) else {
print("Unable to add device input to the capture session.")
return false
}
/// Add the input and output to session
captureSession.addInput(deviceInput)
/// Configure the video data output
videoDataOutput.setSampleBufferDelegate(
self, queue: videoDataOutputQueue)
if captureSession.canAddOutput(videoDataOutput) {
captureSession.addOutput(videoDataOutput)
videoDataOutput.connection(with: .video)?
.preferredVideoStabilizationMode = .off
} else {
return false
}
// Set zoom and autofocus to help focus on very small text
do {
try captureDevice.lockForConfiguration()
captureDevice.videoZoomFactor = 2
captureDevice.autoFocusRangeRestriction = .near
captureDevice.unlockForConfiguration()
} catch {
print("Could not set zoom level due to error: \(error)")
return false
}
captureSession.commitConfiguration()
// potential issue with background vs dispatchqueue ??
Task(priority: .background) {
captureSession.startRunning()
}
return true
}
}
// Issue here ???
extension CameraManager: AVCaptureVideoDataOutputSampleBufferDelegate {
func captureOutput(
_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer,
from connection: AVCaptureConnection
) {
guard let pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else { return }
Task {
textRequest.recognitionLevel = .fast
textRequest.recognitionLanguages = [Locale.Language(identifier: "en-US")]
do {
let observations = try await textRequest.perform(on: pixelBuffer)
for observation in observations {
let recognizedText = observation.topCandidates(1).first
print("recognized text \(recognizedText)")
}
} catch {
print("Recognition error: \(error.localizedDescription)")
}
}
}
}
The results I get look like this ( full page of English from a any book)
recognized text Optional(RecognizedText(string: e bnUI W4, confidence: 0.5))
recognized text Optional(RecognizedText(string: ?'U, confidence: 0.3))
recognized text Optional(RecognizedText(string: traQt4, confidence: 0.3))
recognized text Optional(RecognizedText(string: li, confidence: 0.3))
recognized text Optional(RecognizedText(string: 15,1,#, confidence: 0.3))
recognized text Optional(RecognizedText(string: jllÈ, confidence: 0.3))
recognized text Optional(RecognizedText(string: vtrll, confidence: 0.3))
recognized text Optional(RecognizedText(string: 5,1,: 11, confidence: 0.5))
recognized text Optional(RecognizedText(string: 1141, confidence: 0.3))
recognized text Optional(RecognizedText(string: jllll ljiiilij41, confidence: 0.3))
recognized text Optional(RecognizedText(string: 2f4, confidence: 0.3))
recognized text Optional(RecognizedText(string: ktril, confidence: 0.3))
recognized text Optional(RecognizedText(string: ¥LLI, confidence: 0.3))
recognized text Optional(RecognizedText(string: 11[Itl,, confidence: 0.3))
recognized text Optional(RecognizedText(string: 'rtlÈ131, confidence: 0.3))
Even with ROI set to a specific rectangle Normalized to Vision, I get the same results with single characters returning gibberish.
Any help would be amazing thank you.
Am I using the buffer right ?
Am I using the new perform(on: CVPixelBuffer) right ?
Maybe I didn't set up my camera properly? I can provide code
Environment
MacOC 26
Xcode Version 26.0 beta 7 (17A5305k)
simulator: iPhone 16 pro
iOS: iOS 26
Problem
NLContextualEmbedding.load() fails with the following error
In simulator
Failed to load embedding from MIL representation: filesystem error: in create_directories: Permission denied ["/var/db/com.apple.naturallanguaged/com.apple.e5rt.e5bundlecache"]
filesystem error: in create_directories: Permission denied ["/var/db/com.apple.naturallanguaged/com.apple.e5rt.e5bundlecache"]
Failed to load embedding model 'mul_Latn' - '5C45D94E-BAB4-4927-94B6-8B5745C46289'
assetRequestFailed(Optional(Error Domain=NLNaturalLanguageErrorDomain Code=7 "Embedding model requires compilation" UserInfo={NSLocalizedDescription=Embedding model requires compilation}))
in #Playground
I'm new to this embedding model. Not sure if it's caused by my code or environment.
Code snippet
import Foundation
import NaturalLanguage
import Playgrounds
#Playground {
// Prefer initializing by script for broader coverage; returns NLContextualEmbedding?
guard let embeddingModel = NLContextualEmbedding(script: .latin) else {
print("Failed to create NLContextualEmbedding")
return
}
print(embeddingModel.hasAvailableAssets)
do {
try embeddingModel.load()
print("Model loaded")
} catch {
print("Failed to load model: \(error)")
}
}
Hi, recently i tried to fine-tune Gemma-2-2b mlx model on my macbook (24 GB UMA). The code started running, after few seconds i saw swap size reaching 50GB and ram around 23 GB and then it stopped. I ran the Gemma-2-2b (cuda) on colab, it ran and occupied 27 GB on A100 gpu and worked fine. Here i didn't experienced swap issue.
Now my question is if my UMA was more than 27 GB, i also would not have experienced swap disk issue.
Thanks.
Topic:
Machine Learning & AI
SubTopic:
General
I have used mlx_lm.lora to fine tune a mistral-7b-v0.3-4bit model with my data. I fused the mistral model with my adapters and upload the fused model to my directory on huggingface. I was able to use mlx_lm.generate to use the fused model in Terminal. However, I don't know how to load the model in Swift. I've used
Imports
import SwiftUI
import MLX
import MLXLMCommon
import MLXLLM
let modelFactory = LLMModelFactory.shared
let configuration = ModelConfiguration(
id: "pharmpk/pk-mistral-7b-v0.3-4bit"
)
// Load the model off the main actor, then assign on the main actor
let loaded = try await modelFactory.loadContainer(configuration: configuration)
{ progress in
print("Downloading progress: \(progress.fractionCompleted * 100)%")
}
await MainActor.run {
self.model = loaded
}
I'm getting an error
runModel error: downloadError("A server with the specified hostname could not be found.")
Any suggestions?
Thanks, David
PS, I can load the model from the app bundle
// directory: Bundle.main.resourceURL!
but it's too big to upload for Testflight
Topic:
Machine Learning & AI
SubTopic:
General
Hi
We're on tensorflow 2.20 that has support now for python 3.13 (finally!). tensorflow-metal is still only supporting 2.18 which is over a year old.
When can we expect to see support in tensorflow-metal for tf 2.20 (or later!) ?
I bought a mac thinking I would be able to get great performance from the M processors but here I am using my CPU for my ML projects.
If it's taking so long to release it, why not open source it so the community can keep it more up to date?
cheers
Matt
Hi team,
I’m exploring the Model Context Protocol (MCP), which is used to connect LLMs/AI agents to external tools in a structured way. It's becoming a common standard for automation and agent workflows.
Before I go deeper, I want to confirm:
Does Apple currently provide any official MCP server, API surface, or SDK on iOS/macOS?
From what I see, only third-party MCP servers exist for iOS simulators/devices, and Apple’s own frameworks (Foundation Models, Apple Intelligence) don’t expose MCP endpoints.
Is there any chance Apple might introduce MCP support—or publish recommended patterns for safely integrating MCP inside apps or developer tools?
I would like to see if I can share my app's data to the MCP server to enable other third-party apps/services to integrate easily
Topic:
Machine Learning & AI
SubTopic:
General
We are developing Apple AI for overseas markets and adapting it for iPhone 17 and later models. When the system language and Siri language do not match—such as the system being in English while Siri is in Chinese—it may result in Apple AI being unusable. So, I would like to ask, how can this issue be resolved, and are there other reasons that might cause it to be unusable within the app?
It is vital for Apple to refine its OCR models to correctly distinguish between Khmer and Thai scripts. Incorrectly labeling Khmer text as Thai is more than a technical bug; it is a culturally insensitive error that impacts national identity, especially given the current geopolitical climate between Cambodia and Thailand. Implementing a more robust language-detection threshold would prevent these harmful misidentifications.
There is a significant logic flaw in the VNRecognizeTextRequest language detection when processing Khmer script. When the property automaticallyDetectsLanguage is set to true, the Vision framework frequently misidentifies Khmer characters as Thai.
While both scripts share historical roots, they are distinct languages with different alphabets. Currently, the model’s confidence threshold for distinguishing between these two scripts is too low, leading to incorrect OCR output in both developer-facing APIs and Apple’s native ecosystem (Preview, Live Text, and Photos).
import SwiftUI
import Vision
class TextExtractor {
func extractText(from data: Data, completion: @escaping (String) -> Void) {
let request = VNRecognizeTextRequest { (request, error) in
guard let observations = request.results as? [VNRecognizedTextObservation] else {
completion("No text found.")
return
}
let recognizedStrings = observations.compactMap { observation in
let str = observation.topCandidates(1).first?.string
return "{text: \(str!), confidence: \(observation.confidence)}"
}
completion(recognizedStrings.joined(separator: "\n"))
}
request.automaticallyDetectsLanguage = true // <-- This is the issue.
request.recognitionLevel = .accurate
let handler = VNImageRequestHandler(data: data, options: [:])
DispatchQueue.global(qos: .background).async {
do {
try handler.perform([request])
} catch {
completion("Failed to perform OCR: \(error.localizedDescription)")
}
}
}
}
Recognizing Khmer
Confidence Score is low for Khmer text. (The output is in Thai language with low confidence score)
Recognizing English
Confidence Score is high expected.
Recognizing Thai
Confidence Score is high as expected
Issues on Preview, Photos
Khmer text
Copied text
Kouk Pring Chroum Temple [19121 รอาสายสุกตีนานยารรีสใหิสรราภูชิตีนนสุฐตีย์ [รุก
เผือชิษาธอยกัตธ์ตายตราพาษชาณา ถวเชยาใบสราเบรถทีมูสินตราพาษชาณา ทีมูโษา เช็ก
อาษเชิษฐอารายสุกบดตพรธุรฯ ตากร"สุก"ผาตากรธกรธุกเยากสเผาพศฐตาสาย รัอรณาษ"ตีพย"
สเผาพกรกฐาภูชิสาเครๆผู:สุกรตีพาสเผาพสรอสายใผิตรรารตีพสๆ เดียอลายสุกตีน
ธาราชรติ ธิพรหณาะพูชุบละเาหLunet De Lajonquiere ผารูกรสาราพารผรผาสิตภพ ตารสิทูก ธิพิ
คุณที่นสายเระพบพเคเผาหนารเกะทรนภาษเราภุพเสารเราษทีเลิกสญาเราหรุฬารชสเกาก เรากุม
สงสอบานตรเราะากกต่ายภากายระตารุกเตียน
Recommended Solutions
1. Set a Threshold
Filter out the detected result where the threshold is less than or equal to 0.5, so that it would not output low quality text which can lead to the issue.
For example,
let recognizedStrings = observations.compactMap { observation in
if observation.confidence <= 0.5 {
return nil
}
let str = observation.topCandidates(1).first?.string
return "{text: \(str!), confidence: \(observation.confidence)}"
}
2. Add Khmer Language Support
This issue would never happen if the model has the capability to detect and recognize image with Khmer language.
Doc2Text GitHub: https://github.com/seanghay/Doc2Text-Swift
Hi everyone😊, I want to implement facial recognition into my app. I was planning to use createML's image classification, but there seams to be a lot of hassle to implement (the JSON file etc.). Are there some other easy to implement options that don't involve advanced coding. Thanks, Oliver
Topic:
Machine Learning & AI
SubTopic:
General
We are using VNRecognizeTextRequest to detect text in documents, and we have noticed that even in some very clear and well-formatted documents, there are still instances where text blocks are missed. the live text also have the same issue.
We are building an app which can reads texts. It can read english and Japanese normal texts successfully. But in some cases, we need to read Japanese tategaki (vertically aligned texts). But in that times, the same code gives no output. So, is there any need to change any configuration to read Japanese tategaki? Or is it really possible to read Japanese tategaki using vision framework?
lazy var detectTextRequest = VNRecognizeTextRequest { request, error in
self.resStr="\n"
self.words = [:]
// Get OCR result
guard let res = request.results as? [VNRecognizedTextObservation] else { return }
// separate the words by space
let text = res.compactMap({$0.topCandidates(1).first?.string}).joined(separator: " ")
var n = 0
self.wordArr=[[]]
self.xs = 1
self.ys = 1
var hs = 0.0 // To compare the heights of the words
// To get the original axis (top most word's axis), only once
for r in res {
var word = r.topCandidates(1).first?.string
self.words[word ?? ""] = [r.topLeft.x, r.topLeft.y]
if(self.cartLabelType == 1){
if(word?.components(separatedBy: CharacterSet(charactersIn: "//")).count ?? 0>2){
self.xs = r.topLeft.x
self.ys = r.topLeft.y
}
}
}
}
}
Is there any way to stop GPU work running that is scheduled using metal?
Long shader calculations don't stop when application is stopped in Xcode and continue to take up GPU time and affect the display.
Why is this functionality not available when Swift Tasks are able to be canceled?
Topic:
Machine Learning & AI
SubTopic:
General
Hi,
One can configure the languages of a (VN)RecognizeTextRequest with either:
.automatic: language to be detected
a specific language, say Spanish
If the request is configured with .automatic and successfully detects Spanish, will the results be exactly equivalent compared to a request made with Spanish set as language?
I could not find any information about this, and this is very important for the core architecture of my app.
Thanks!
Hi everyone! 👋
I'm working on a C++ project using TensorFlow Lite and was wondering if anyone has a prebuilt TensorFlow Lite C++ library (libtensorflowlite) for macOS (Apple Silicon M1/M2) that they’d be willing to share.
I’m looking specifically for the TensorFlow Lite C++ API — something that lets me use tflite::Interpreter, tflite::FlatBufferModel, etc. Building it from source using Bazel on macOS has been quite challenging and time-consuming, so a ready-to-use .dylib or .a build along with the required headers would be incredibly helpful.
TensorFlow Lite version: v2.18.0 preferred
Target: macOS arm64 (Apple Silicon)
What I need:
libtensorflowlite.dylib or .a
Corresponding headers (ideally organized in a clean include/ folder)
If you have one available or know where I can find a reliable prebuilt version, I’d be super grateful. Thanks in advance! 🙏
The WWDC25: Explore large language models on Apple silicon with MLX video talks about using your own data to fine-tune a large language model. But the video doesn't explain what kind of data can be used. The video just shows the command to use and how to point to the data folder. Can I use PDFs, Word documents, Markdown files to train the model? Are there any code examples on GitHub that demonstrate how to do this?