El Bruno

⚠️ This blog post was created with the help of AI tools. Yes, I used a bit of magic from language models to organize my thoughts and automate the boring parts, but the geeky fun and the 🤖 in C# are 100% mine.

Hi!

If you are building local AI apps in C#, you quickly hit a practical gap:

• Foundry Local SDK is great for local/on-device inference.
• Microsoft.Extensions.AI and Microsoft Agent Framework expect an IChatClient.
• There is no first-party Foundry Local -> IChatClient bridge yet.

That is exactly why I created this library

• Nuget: https://www.nuget.org/packages/ElBruno.MAF.FoundryLocal.Adapter
• Repo: https://github.com/elbruno/ElBruno.MAF.FoundryLocal/
• Sample: ElBruno.MAF.FoundryLocal/src/ElBruno.MAF.FoundryLocal.Console at main · elbruno/ElBruno.MAF.FoundryLocal

Why I created this

I wanted a clean, non-REST, in-process integration where:

1. Foundry Local stays local and private.
2. My app code uses standard MEAI abstractions (IChatClient).
3. The same IChatClient can be reused by Microsoft Agent Framework.

So the library provides a thin adapter:

Foundry Local SDK -> FoundryLocalChatClientAdapter -> IChatClient

This lets you write provider-agnostic app code while still running local inference.

Minimal usage

Install:

dotnet add package ElBruno.MAF.FoundryLocal.Adapter
dotnet add package Microsoft.Extensions.Hosting
dotnet add package Microsoft.Agents.AI

Use the wrapper as IChatClient:

using ElBruno.MAF.FoundryLocal;
using Microsoft.Extensions.AI;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

var builder = Host.CreateApplicationBuilder(args);

builder.Services.Configure<FoundryLocalOptions>(o =>
{
    o.ModelAlias = "qwen2.5-0.5b";
    o.DownloadIfMissing = true;
    o.UnloadOnExit = true;
});

builder.Services.Configure<ChatRuntimeOptions>(_ => { });
builder.Services.AddSingleton<FoundryLocalModelLifecycleService>();
builder.Services.AddSingleton<IChatClient, FoundryLocalChatClientAdapter>();

using var host = builder.Build();
var chatClient = host.Services.GetRequiredService<IChatClient>();

var response = await chatClient.GetResponseAsync(
[
    new(ChatRole.User, "Explain local-first AI in one paragraph.")
]);

Console.WriteLine(response.Text);

Reuse the same wrapper with Microsoft Agent Framework:

using Microsoft.Agents.AI;

var agent = new ChatClientAgent(
    chatClient: chatClient,
    instructions: "You are a concise local assistant.",
    name: "LocalFoundryAgent",
    description: "Foundry Local + IChatClient adapter",
    tools: null,
    loggerFactory: null,
    services: null);

var agentResponse = await agent.RunAsync(
    "Give me 3 bullet points about local AI in .NET.",
    session: null,
    options: null);

Console.WriteLine(agentResponse);

What this gives you

• Local inference through Foundry Local SDK
• No local REST server required
• Standard MEAI IChatClient programming model
• Easy path to Agent Framework agents

In short: local model runtime + standard .NET AI abstractions + minimal glue code.