foundation-models-server

A lightweight OpenAI-compatible HTTP server that wraps Apple's Foundation Models framework, enabling Jan to use on-device Apple Intelligence models on macOS 26+.

Requirements

• macOS 26 (Tahoe) or later
• Apple Silicon Mac with Apple Intelligence enabled
• Xcode 26 or later

Building

swift build -c release

The binary will be at .build/release/foundation-models-server.

Usage

# Check availability
foundation-models-server --check

# Start server on default port
foundation-models-server --port 8080

# Start server with API key
foundation-models-server --port 8080 --api-key <key>

API

The server exposes an OpenAI-compatible API:

• GET /health — health check
• GET /v1/models — lists the apple/on-device model
• POST /v1/chat/completions — chat completions (streaming and non-streaming)

The model ID is always apple/on-device.