axiom-foundation-models-ref

Document the on-device Foundation Models API for iOS, macOS, and iPadOS.

1|Updated Feb 8, 2026
One-click install
npx skills add https://github.com/foxtrottwist/ClaudeAgentConfig --skill axiom-foundation-models-ref
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: axiom-foundation-models-ref
Source: https://github.com/foxtrottwist/ClaudeAgentConfig/tree/main/xcode-agent/skills/axiom-foundation-models-ref
Command: npx skills add https://github.com/foxtrottwist/ClaudeAgentConfig --skill axiom-foundation-models-ref

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This reference provides a complete on-device Foundation Models API guide and WWDC 2025 code examples for LanguageModelSession, @Generable, Tool protocol, streaming, and dynamic schemas to accelerate building offline AI features.

Core Features & Use Cases

  • Comprehensive API reference for LanguageModelSession, SystemLanguageModel, @Generable, and Tool protocol
  • Guidance on streaming, dynamic schemas, constrained decoding, and performance profiling
  • Real WWDC 2025 code examples to accelerate production-ready implementations across iOS, macOS, and iPadOS

Quick Start

Initialize a LanguageModelSession and experiment with respond(to:generating:) to generate a typed result using @Generable.

Frequently Asked Questions about axiom-foundation-models-ref

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I generate structured outputs from on-device foundation models in iOS?▼

To generate structured outputs from on-device foundation models, initialize a LanguageModelSession and use the respond(to:generating:) method with the @Generable macro to produce typed results directly within your iOS app.

What is the Tool protocol used for in Apple's Foundation Models API?▼

The Tool protocol in the Foundation Models API defines structured interfaces that allow a LanguageModelSession to interact with external functions, enabling on-device models to execute specific actions and fetch dynamic data during generation.

Does the Foundation Models API support constrained decoding and dynamic schemas for on-device AI?▼

Yes, the Foundation Models API supports constrained decoding and dynamic schemas, allowing developers to enforce specific output structures and adapt generation logic dynamically during a LanguageModelSession on iOS and macOS.

How do I stream responses from an on-device language model session?▼

You can stream responses from a LanguageModelSession by utilizing the built-in streaming capabilities provided by the Foundation Models API, which delivers generated tokens incrementally for real-time UI updates in iOS applications.

What are the performance considerations when using Generable types with on-device AI?▼

Performance considerations for Generable types include profiling schema complexity and managing constrained decoding overhead, ensuring the on-device LanguageModelSession maintains responsive generation times across iOS, macOS, and iPadOS deployments.

Can I use SystemLanguageModel to check on-device foundation model availability before starting a session?▼

Yes, SystemLanguageModel provides the interface to verify on-device foundation model availability and capabilities, ensuring your iOS app safely initializes a LanguageModelSession only when the underlying generable hardware and software support are present.