Community.Microsoft.Extensions.AI.CoreML

Use Apple Intelligence on-device models directly from .NET — through the familiar IChatClient interface.

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What is it?

Community.Microsoft.Extensions.AI.CoreML is an open-source IChatClient implementation that talks directly to Apple's on-device Foundation Models (Apple Intelligence) from .NET — no MAUI workload, no local HTTP server, no cloud calls.

The same IChatClient you already use with OpenAI, Azure OpenAI, or Ollama now works against the private, on-device model that ships with every Apple Silicon Mac running macOS 26+.

Why use it?

• 🆓 Free — no API costs, no rate limits
• 🔒 Private — prompts and responses never leave the device
• ⚡ Fast — no network hop
• ✈️ Offline — works without internet
• 🪶 Lightweight — a single NuGet package that bundles a small native bridge dylib; no MAUI required

What's inside?

flowchart LR
    App[".NET app<br/>IChatClient"] -->|Microsoft.Extensions.AI| Client["AppleIntelligenceChatClient"]
    Client -->|P/Invoke| Dylib["libAppleIntelligenceBridge.dylib<br/>Swift / C bridge"]
    Dylib -->|Swift API| FM["Apple Foundation Models<br/>LanguageModelSession"]

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Supports plain completions, streaming, multi-turn conversations, and tool / function calling (compatible with Microsoft.Agents.AI).

For a deeper look at the design, see docs/architecture.md.

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How to install

Requirements

Requirement	Version
macOS	26.0 or later
Architecture	Apple Silicon (M1 or later)
Apple Intelligence	Enabled in System Settings → Apple Intelligence & Siri
.NET	10.0 or later

The package ships the pre-built native bridge dylib for osx-arm64. Other platforms throw PlatformNotSupportedException at construction.

Add the package:

dotnet add package Community.Microsoft.Extensions.AI.CoreML --prerelease

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How to use it

1. Basic completion

using Community.Microsoft.Extensions.AI.CoreML;
using Microsoft.Extensions.AI;

IChatClient client = new AppleIntelligenceChatClient();

var response = await client.GetResponseAsync(
    "Summarise the key ideas of stoicism in three bullet points.");

Console.WriteLine(response.Text);

2. Streaming

await foreach (var update in client.GetStreamingResponseAsync("Tell me a short story."))
{
    Console.Write(update.Text);
}

3. Multi-turn conversation

var history = new List<ChatMessage>
{
    new(ChatRole.System, "You are a concise assistant."),
    new(ChatRole.User,   "What is the capital of Belgium?"),
};

var reply = await client.GetResponseAsync(history);
history.AddRange(reply.Messages);

history.Add(new ChatMessage(ChatRole.User, "And of France?"));
var follow = await client.GetResponseAsync(history);
Console.WriteLine(follow.Text);

4. Dependency injection

using Community.Microsoft.Extensions.AI.CoreML;

services
    .AddAppleIntelligenceChatClient()
    .UseFunctionInvocation();   // any IChatClient middleware works here

Then inject IChatClient anywhere:

public class ChatService(IChatClient client)
{
    public Task<ChatResponse> AskAsync(string prompt) =>
        client.GetResponseAsync(prompt);
}

5. Tool / function calling

Works out of the box with Microsoft.Agents.AI:

using Microsoft.Agents.AI;
using Microsoft.Extensions.AI;

string GetWeather(string location) => $"It is cloudy in {location} with a high of 15°C.";

var agent = new AppleIntelligenceChatClient()
    .AsAIAgent(
        name: "WeatherAgent",
        instructions: "You are a helpful weather assistant.",
        tools: [AIFunctionFactory.Create(GetWeather, "GetWeather", "Get the weather for a given location.")]);

var reply = await agent.RunAsync("What's the weather in New York?");
Console.WriteLine(reply.Messages.Last().Text);
// → "It is cloudy in New York with a high of 15°C."

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Leave feedback

This project is brand new and community-driven — your feedback genuinely shapes where it goes next.

• 🐛 Found a bug? → Open an issue
• 💡 Have an idea or feature request? → Open an issue
• 💬 Want to discuss usage, share what you built, or ask a question? → Start a discussion
• ⭐ Like the project? → A GitHub star is the easiest way to tell us it's useful

When reporting a bug, please include:

• macOS version (sw_vers -productVersion)
• .NET SDK version (dotnet --version)
• A minimal repro (a few lines of code + the exception or unexpected output)

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License

MIT — © Community Contributors