public record class Cat(string Name);
public record class Dog(string Name);
public record class Bird(string Name);
 
public union Pet(Cat, Dog, Bird);

Pet pet = new Dog("Rex");
Console.WriteLine(pet.Value); // Dog { Name = Rex }
 
Pet pet2 = new Cat("Whiskers");
Console.WriteLine(pet2.Value); // Cat { Name = Whiskers }

string name = pet switch
{
    Dog d => d.Name,
    Cat c => c.Name,
    Bird b => b.Name,
};

Pet pet = default;
 
var description = pet switch
{
    Dog d => d.Name,
    Cat c => c.Name,
    Bird b => b.Name,
    null => "no pet",
};
// description is "no pet"

public union OneOrMore<T>(T, IEnumerable<T>)
{
    public IEnumerable<T> AsEnumerable() => Value switch
    {
        T single => [single],
        IEnumerable<T> multiple => multiple,
        null => []
    };
}

OneOrMore<string> tags = "dotnet";
OneOrMore<string> moreTags = new[] { "csharp", "unions", "preview" };
 
foreach (var tag in tags.AsEnumerable())
    Console.Write($"[{tag}] ");
// [dotnet]
 
foreach (var tag in moreTags.AsEnumerable())
    Console.Write($"[{tag}] ");
// [csharp] [unions] [preview]

namespace System.Runtime.CompilerServices
{
    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct,
        AllowMultiple = false)]
    public sealed class UnionAttribute : Attribute;
 
    public interface IUnion
    {
        object? Value { get; }
    }
}

public record class Cat(string Name);
public record class Dog(string Name);
 
public union Pet(Cat, Dog);
 
Pet pet = new Cat("Whiskers");
Console.WriteLine(pet switch
{
    Cat c => $"Cat: {c.Name}",
    Dog d => $"Dog: {d.Name}",
});

# pip install agent-framework
# Use `az login` to authenticate with Azure CLI
 
import asyncio
 
from agent_framework import Agent
from agent_framework.foundry import FoundryChatClient
from azure.identity import AzureCliCredential
 
agent = Agent(
*** client= FoundryChatClient(
**** *project_endpoint="https://your-project.services.ai.azure.com",
***** model="gpt-5.3",
* ****credential=AzureCliCredential(),
*** ),
*** name="HelloAgent",
*** instructions="You are a friendly assistant."
)
 
print(asyncio.run(agent.run("Write a haiku about shipping 1.0.")))

// dotnet add package Microsoft.Agents.AI.OpenAI --prerelease
using Microsoft.Agents.AI;
using Microsoft.Agents.AI.Foundry
using Azure.Identity;
 
// Replace the <apikey> with your OpenAI API key.
var agent = new AIProjectClient(endpoint:"https://your-project.services.ai.azure.com")
*** .GetResponsesClient("gpt-5.3")
*** .AsAIAgent(
        name: "HaikuBot", 
        instructions: "You are an upbeat assistant that writes beautifully."
    );
 
Console.WriteLine(await agent.RunAsync("Write a haiku about shipping 1.0."));

import asyncio
 
from agent_framework import Agent, Message
from agent_framework.foundry import FoundryChatClient
from agent_framework.orchestrations import SequentialBuilder
from azure.identity import AzureCliCredential
 
 
async def main() -> None:
*** # credentials read from .env
*** client = FoundryChatClient(credential=AzureCliCredential())
 
*** writer = Agent(
******* client=client,
******* instructions="You are a concise copywriter. Provide a single, punchy marketing sentence.",
******* name="writer",
*** )
 
*** reviewer = Agent(
******* client=client,
******* instructions="You are a thoughtful reviewer. Give brief feedback on the previous message.",
******* name="reviewer",
*** )
 
 
*** workflow = SequentialBuilder(participants=[writer, reviewer]).build()
*** outputs: list[list[Message]] = []
*** async for event in workflow.run("Write a tagline for Microsoft Agent Framework 1.0.", stream=True):
******* if event.type == "output":
*********** outputs.append(cast(list[Message], event.data))
*** if outputs:
******* for msg in outputs[-1]:
*********** print(f"[{msg.author_name or 'user'}]: {msg.text}")
 
if __name__ == "__main__":
*** asyncio.run(main())

var builder = DistributedApplication.CreateBuilder(args);
 
var cache = builder.AddRedis("cache");
 
var api = builder.AddNodeApp("api", "./api", "src/index.ts")
    .WithReference(cache)
    .WaitFor(cache)
    .WithHttpEndpoint(env: "PORT")
    .WithExternalHttpEndpoints();
 
builder.AddViteApp("frontend", "./frontend")
    .WithReference(api)
    .WaitFor(api);
 
builder.Build().Run();

import { createBuilder } from './.modules/aspire.js';
 
const builder = await createBuilder();
 
const cache = await builder.addRedis("cache");
 
const api = await builder
    .addNodeApp("api", "./api", "src/index.ts")
    .withReference(cache)
    .waitFor(cache)
    .withHttpEndpoint({ env: "PORT" })
    .withExternalHttpEndpoints();
 
await builder
    .addViteApp("frontend", "./frontend")
    .withReference(api)
    .waitFor(api);
 
await builder.build().run();

aspire start
aspire resource api restart
aspire wait api --status healthy --timeout 120