Getting Started

Requirements

• macOS 26 (Tahoe) or later, Apple Silicon
• Apple Intelligence enabled in System Settings
• Node.js 20+

Installation

npm install tsfm-sdk

A prebuilt libFoundationModels.dylib is bundled with the package — Xcode is not required. If your machine needs a different build, see Building from Source.

Quick Start

import { SystemLanguageModel, LanguageModelSession } from "tsfm-sdk";

const model = new SystemLanguageModel();
const { available } = await model.waitUntilAvailable();
if (!available) process.exit(1);

const session = new LanguageModelSession({
  instructions: "You are a concise assistant.",
});

const reply = await session.respond("What is the capital of France?");
console.log(reply); // "The capital of France is Paris."

session.dispose();
model.dispose();

Key Concepts

1. Model — SystemLanguageModel represents the on-device model. Check availability before creating sessions.
2. Session — LanguageModelSession maintains conversation state. All generation methods go through a session.
3. Dispose — Native resources must be released by calling dispose() when you're done.

What's Next

• Model Configuration — Use cases, guardrails, availability
• Sessions — Creating and using sessions
• Streaming — Token-by-token response streaming
• Structured Output — Typed generation with schemas
• Tools — Function calling
• Error Handling — Error types and recovery

Building from Source

If you need to rebuild the native library:

git clone https://github.com/codybrom/tsfm.git
cd tsfm
npm run build

This requires Xcode 26+ to compile the Swift bridge.