core-ml
Core ML, Create ML, Vision framework, Natural Language framework, on-device ML integration. Use when user wants image classification, text analysis, object detection, sound classification, model optimization, or custom model integration. Covers Core ML vs Foundation Models decision.
By rshankras · 370 installs
npx skills add rshankras/claude-code-apple-skills --skill core-ml
Source repository · Upstream listing
Core ML Skills
Combined advisory, generator, and workflow skill for integrating machine learning into Apple platform apps. Covers Core ML model integration, Vision framework image analysis, NaturalLanguage framework text processing, Create ML training, and on device model optimization.
When This Skill Activates
Use this skill when the user:
Wants to add ML capabilities to their app
Needs to integrate a Core ML model (.mlmodel) into an Xcode project
Wants to use the Vision framework for image analysis (faces, text recognition, body pose, object detection)
Wants to use the NaturalLanguage framework for text processing (sentiment, entities, language detection)
Needs to train a custom model with Create ML
Wants to optimize a model for on device use (quantization, pruning, palettization)
Needs to choose between Core ML and Foundation Models (Apple Intelligence)
Asks about image classification, object detection, sound classification, or tabular data prediction
Wants real time camera + ML processing
Decision Guide: Core ML vs Foundation Models
Before generating code, determine which framework is appropriate.
Use Foundation Models (Apple Intelligence) When:
You need general purpose text generation, summarization, or conversational AI
Target is iOS 26+ / macOS 26+ (Foundation Models requires Apple Silicon + latest OS)
The task is open ended language understanding or generation
You want @Generable structured output from natural language
See apple intelligence/foundation models/ skill for implementation
Use Core ML When:
You need specialized ML: image classification, object detection, sound classification, custom regression/classification
You have a trained model (.mlmodel, .mlpackage) or plan to train one
You need broad device support (iOS 14+ / macOS 11+)
The task requires domain specific predictions (medical imaging, product recognition, custom NLP)
Performance critical inference on Neural Engine or GPU
Use Vision Framework When (No Custom Model Needed):
Image classification using Apple's built in models
Face detection and facial landmark analysis
Text recognition (OCR) with VNRecognizeTextRequest
Body and hand pose detection
Barcode and QR code scanning
Image similarity and saliency detection
Horizon detection, rectangle detection
Use NaturalLanguage Framework When (No Custom Model Needed):
Sentiment analysis on text
Language identification
Tokenization (word, sentence, paragraph boundaries)
Named entity recognition (people, places, organizations)
Word and sentence embeddings for similarity comparison
Lemmatization and part of speech tagging
Pre Generation Checks
1. Project Context Detection
[ ] Check deployment target (Core ML requires iOS 11+ / macOS 10.13+; Vision requires iOS 11+; NaturalLanguage requires iOS 12+)
[ ] Check for existing ML code or models
[ ] Identify project structure and source file locations
[ ] Determine if SwiftUI or UIKit/AppKit
2. Conflict Detection
Search for existing ML integration:
If found, ask user:
Extend existing ML setup?
Replace with new implementation?
Add additional model/capability?
Configuration Questions
Ask user via AskUserQuestion:
1. What ML capability do you need?
Image classification (identify objects in photos)
Object detection (locate objects with bounding boxes)
Text analysis (sentiment, entities, language)
Custom Core ML model integration
Vision framework (OCR, faces, poses)
Sound classification
Tabular data prediction
2. Do you have a trained model, or need to train one?
I have a .mlmodel / .mlpackage file
I want to train with Create ML
I want to use Apple's built in models (Vision / NaturalLanguage)
3. Performance requirements?
Real time (camera feed, < 33ms per prediction)
Interactive (user initiated, < 500ms acceptable)
Background processing (batch, latency not critical)
Core ML Model Integration
Adding a Model to Xcode
1. Drag .mlmodel or .mlpackage into Xcode project navigator
2. Xcode auto generates a Swift class with the model name
3. The generated class provides type safe input/output interfaces
4. Xcode compiles to .mlmodelc at build time (optimized for device)
Loading Models
Making Predictions
Create ML Training Overview
Image Classification
Minimum : 10 images per category; Recommended : 40+ per category
Organize images in folders named by category
Supports JPEG, PNG, HEIC formats
Data augmentation applied automatically (rotation, flip, crop)
Transfer learning from Apple's base models
Text Classification
Training data: text samples with labels (CSV or JSON)
Use cases: sentiment analysis, spam detection, topic classification, intent recognition
Minimum 10 samples per class; 100+ recommended for accuracy
Tabular Classification / Regression
Structured data in CSV or JSON
Automatic feature engineering
Supports: Boosted Tree, Random Forest, Linear Regression, Decision Tree
Sound Classification
Audio files organized by category
Environmental sounds, speech detection, music genre
Minimum 10 samples per category at 15+ seconds each
Object Detection
Images with bounding box annotations (JSON format)
Outputs bounding boxes + class labels + confidence
Minimum 30 annotated images per class; 300+ recommended
Training Approach
Xcode Create ML App : Visual interface, drag and drop, no code required
CreateML Framework : Programmatic training in Swift Playgrounds or macOS apps
coremltools (Python) : Convert models from TensorFlow, PyTorch, ONNX to Core ML format
Vision Framework Capabilities
Capability Request Class Custom Model Needed?
Image classification VNClassifyImageRequest No (built in)
Object detection VNDetectObjectsRequest (custom model) Yes
Face detection VNDetectFaceRectanglesRequest No
Face landmarks VNDetectFaceLandmarksRequest No
Text recognition (OCR) VNRecognizeTextRequest No
Body pose VNDetectHumanBodyPoseRequest No
Hand pose VNDetectHumanHandPoseRequest No
Barcode detection VNDetectBarcodesRequest No
Image saliency VNGenerateAttentionBasedSaliencyImageRequest No
Horizon detection VNDetectHorizonRequest No
Rectangle detection VNDetectRectanglesRequest No
Image similarity VNGenerateImageFeaturePrintRequest No
Vision Request Pipeline
NaturalLanguage Framework
Sentiment Analysis
Language Detection
Tokenization
Named Entity Recognition
Model Optimization
Quantization (coremltools Python)
Reduces model size by lowering numerical precision:
Float32 to Float16 : ~50% size reduction, minimal accuracy loss
Float16 to Int8 : ~50% further reduction, test accuracy carefully
Palettization
Reduces unique weight values using k means clustering:
Pruning
Removes near zero weights (sparse model):
Optimization Guidelines
Always benchmark accuracy after optimization
Start with Float16 (safest, best effort to reward ratio)
Test on target device (Neural Engine behavior differs from GPU)
Profile with Xcode Instruments Core ML Performance
Performance Patterns
Compute Unit Selection
Async Prediction for UI Responsiveness
Batch Processing
Compile Model at Install Time
Generation Process
Step 1: Determine Capability
Based on user's answer to configuration questions, select the appropriate template(s) from templates.md .
Step 2: Generate Core Files
Capability Files Generated
Any Core ML MLModelManager.swift
Image classification ImageClassifier.swift
Text analysis TextAnalyzer.swift
Vision requests VisionService.swift
Custom model ModelConfig.swift + model specific predictor
Camera + ML CameraMLPipeline.swift
Step 3: Determine File Location
Check project structure:
If Sources/ exists Sources/ML/
If App/Services/ exists App/Services/ML/
If App/ exists App/ML/
Otherwise ML/
Output Format
After generation, provide:
Files Created
Integration Steps
1. Add .mlmodel file to Xcode project (if using custom model)
2. Import the generated ML service files
3. Initialize the service in your app's dependency injection
4. Call prediction methods from your views/view models
5. Handle errors and display results
Testing
Use known test inputs with expected outputs
Verify confidence thresholds
Profile prediction latency on target device
Test graceful degradation when model unavailable
References
patterns.md — Architecture patterns, model manager, Vision pipeline, camera + ML, testing
templates.md — Production ready Swift code templates for all ML capabilities
Apple Docs: [Core ML Documentation](https://developer.apple.com/documentation/coreml)
Apple Docs: [Vision Documentation](https://developer.apple.com/documentation/vision)
Apple Docs: [NaturalLanguage Documentation](https://developer.apple.com/documentation/naturallanguage)
Apple Docs: [Create ML Documentation](https://developer.apple.com/documentation/createml)