| description | Microsoft 365 Agents SDK for .NET. Build multichannel agents for Teams/M365/Copilot Studio with ASP.NET Core hosting, AgentApplication routing, and MSAL-based auth. Triggers: "Microsoft 365 Agents SDK", "Microsoft.Agents", "AddAgentApplicationOptions", "AgentApplication", "AddAgentAspNetAuthentication", "Copilot Studio client", "IAgentHttpAdapter".
|
| name | m365-agents-dotnet |
| package | Microsoft.Agents.Hosting.AspNetCore, Microsoft.Agents.Authentication.Msal, Microsoft.Agents.CopilotStudio.Client |
| source_file | SKILL.md |
| title | Microsoft 365 Agents SDK (.NET) |
Microsoft 365 Agents SDK (.NET)
Overview
Build enterprise agents for Microsoft 365, Teams, and Copilot Studio using the Microsoft.Agents SDK with ASP.NET Core hosting, agent routing, and MSAL-based authentication.
Before implementation
- Use the microsoft-docs MCP to verify the latest APIs for AddAgent, AgentApplication, and authentication options.
- Confirm package versions in NuGet for the Microsoft.Agents.* packages you plan to use.
Installation
dotnet add package Microsoft.Agents.Hosting.AspNetCore
dotnet add package Microsoft.Agents.Authentication.Msal
dotnet add package Microsoft.Agents.Storage
dotnet add package Microsoft.Agents.CopilotStudio.Client
dotnet add package Microsoft.Identity.Client.Extensions.Msal
Configuration (appsettings.json)
{
"TokenValidation": {
"Enabled": true,
"Audiences": [
"{{ClientId}}"
],
"TenantId": "{{TenantId}}"
},
"AgentApplication": {
"StartTypingTimer": false,
"RemoveRecipientMention": false,
"NormalizeMentions": false
},
"Connections": {
"ServiceConnection": {
"Settings": {
"AuthType": "ClientSecret",
"ClientId": "{{ClientId}}",
"ClientSecret": "{{ClientSecret}}",
"AuthorityEndpoint": "https://login.microsoftonline.com/{{TenantId}}",
"Scopes": [
"https://api.botframework.com/.default"
]
}
}
},
"ConnectionsMap": [
{
"ServiceUrl": "*",
"Connection": "ServiceConnection"
}
],
"CopilotStudioClientSettings": {
"DirectConnectUrl": "",
"EnvironmentId": "",
"SchemaName": "",
"TenantId": "",
"AppClientId": "",
"AppClientSecret": ""
}
}
Core Workflow: ASP.NET Core agent host
using Microsoft.Agents.Builder;
using Microsoft.Agents.Hosting.AspNetCore;
using Microsoft.Agents.Storage;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddHttpClient();
builder.AddAgentApplicationOptions();
builder.AddAgent<MyAgent>();
builder.Services.AddSingleton<IStorage, MemoryStorage>();
builder.Services.AddControllers();
builder.Services.AddAgentAspNetAuthentication(builder.Configuration);
WebApplication app = builder.Build();
app.UseAuthentication();
app.UseAuthorization();
app.MapGet("/", () => "Microsoft Agents SDK Sample");
var incomingRoute = app.MapPost("/api/messages",
async (HttpRequest request, HttpResponse response, IAgentHttpAdapter adapter, IAgent agent, CancellationToken ct) =>
{
await adapter.ProcessAsync(request, response, agent, ct);
});
if (!app.Environment.IsDevelopment())
{
incomingRoute.RequireAuthorization();
}
else
{
app.Urls.Add("http://localhost:3978");
}
app.Run();
AgentApplication routing
using Microsoft.Agents.Builder;
using Microsoft.Agents.Builder.App;
using Microsoft.Agents.Builder.State;
using Microsoft.Agents.Core.Models;
using System;
using System.Threading;
using System.Threading.Tasks;
public sealed class MyAgent : AgentApplication
{
public MyAgent(AgentApplicationOptions options) : base(options)
{
OnConversationUpdate(ConversationUpdateEvents.MembersAdded, WelcomeAsync);
OnActivity(ActivityTypes.Message, OnMessageAsync, rank: RouteRank.Last);
OnTurnError(OnTurnErrorAsync);
}
private static async Task WelcomeAsync(ITurnContext turnContext, ITurnState turnState, CancellationToken ct)
{
foreach (ChannelAccount member in turnContext.Activity.MembersAdded)
{
if (member.Id != turnContext.Activity.Recipient.Id)
{
await turnContext.SendActivityAsync(
MessageFactory.Text("Welcome to the agent."),
ct);
}
}
}
private static async Task OnMessageAsync(ITurnContext turnContext, ITurnState turnState, CancellationToken ct)
{
await turnContext.SendActivityAsync(
MessageFactory.Text($"You said: {turnContext.Activity.Text}"),
ct);
}
private static async Task OnTurnErrorAsync(
ITurnContext turnContext,
ITurnState turnState,
Exception exception,
CancellationToken ct)
{
await turnState.Conversation.DeleteStateAsync(turnContext, ct);
var endOfConversation = Activity.CreateEndOfConversationActivity();
endOfConversation.Code = EndOfConversationCodes.Error;
endOfConversation.Text = exception.Message;
await turnContext.SendActivityAsync(endOfConversation, ct);
}
}
Copilot Studio direct-to-engine client
DelegatingHandler for token acquisition (interactive flow)
using System.Net.Http.Headers;
using Microsoft.Agents.CopilotStudio.Client;
using Microsoft.Identity.Client;
internal sealed class AddTokenHandler : DelegatingHandler
{
private readonly SampleConnectionSettings _settings;
public AddTokenHandler(SampleConnectionSettings settings) : base(new HttpClientHandler())
{
_settings = settings;
}
protected override async Task<HttpResponseMessage> SendAsync(
HttpRequestMessage request,
CancellationToken cancellationToken)
{
if (request.Headers.Authorization is null)
{
string[] scopes = [CopilotClient.ScopeFromSettings(_settings)];
IPublicClientApplication app = PublicClientApplicationBuilder
.Create(_settings.AppClientId)
.WithAuthority(AadAuthorityAudience.AzureAdMyOrg)
.WithTenantId(_settings.TenantId)
.WithRedirectUri("http://localhost")
.Build();
AuthenticationResult authResponse;
try
{
var account = (await app.GetAccountsAsync()).FirstOrDefault();
authResponse = await app.AcquireTokenSilent(scopes, account).ExecuteAsync(cancellationToken);
}
catch (MsalUiRequiredException)
{
authResponse = await app.AcquireTokenInteractive(scopes).ExecuteAsync(cancellationToken);
}
request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", authResponse.AccessToken);
}
return await base.SendAsync(request, cancellationToken);
}
}
Console host with CopilotClient
using Microsoft.Agents.CopilotStudio.Client;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
HostApplicationBuilder builder = Host.CreateApplicationBuilder(args);
var settings = new SampleConnectionSettings(
builder.Configuration.GetSection("CopilotStudioClientSettings"));
builder.Services.AddHttpClient("mcs").ConfigurePrimaryHttpMessageHandler(() =>
{
return new AddTokenHandler(settings);
});
builder.Services
.AddSingleton(settings)
.AddTransient<CopilotClient>(sp =>
{
var logger = sp.GetRequiredService<ILoggerFactory>().CreateLogger<CopilotClient>();
return new CopilotClient(settings, sp.GetRequiredService<IHttpClientFactory>(), logger, "mcs");
});
IHost host = builder.Build();
var client = host.Services.GetRequiredService<CopilotClient>();
await foreach (var activity in client.StartConversationAsync(emitStartConversationEvent: true))
{
Console.WriteLine(activity.Type);
}
await foreach (var activity in client.AskQuestionAsync("Hello!", null))
{
Console.WriteLine(activity.Type);
}
Best Practices
- Use AgentApplication subclasses to centralize routing and error handling.
- Use MemoryStorage only for development; use persisted storage in production.
- Enable TokenValidation in production and require authorization on /api/messages.
- Keep auth secrets in configuration providers (Key Vault, managed identity, env vars).
- Reuse HttpClient from IHttpClientFactory and cache MSAL tokens.
- Prefer async handlers and pass CancellationToken to SDK calls.
Reference Files
Reference Links
