.NET: Add agent hosting package and update sample (#296)

* Add agent hosting package and update sample * Review feedback and cleanup * Include the narrator * wip * wip * Remove workaround for empty state writes. * Handle changes to AgentThread. * One more. * Fix. --------- Co-authored-by: Aditya Mandaleeka <adityam@microsoft.com>
2026-06-16 21:04:09 +08:00 · 2025-08-06 21:26:36 +00:00
parent 8dcc8533a6
commit e7441ee29e
86 changed files with 4388 additions and 1229 deletions
@@ -0,0 +1,145 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Text.Json;
+using Microsoft.AspNetCore.Http.Features;
+using Microsoft.Extensions.AI.Agents.Hosting;
+using Microsoft.Extensions.AI.Agents.Runtime;
+
+namespace AgentWebChat.AgentHost;
+
+internal static class HttpActorProcessor
+{
+    public static async Task<IResult> GetResponseAsync(
+        string actorType,
+        string actorKey,
+        string messageId,
+        bool? blocking,
+        bool? streaming,
+        HttpContext context,
+        IActorClient actorClient,
+        CancellationToken cancellationToken)
+    {
+        var actorId = new ActorId(actorType, actorKey);
+
+        var responseHandle = await actorClient.GetResponseAsync(actorId, messageId, cancellationToken);
+
+        if (responseHandle.TryGetResponse(out var response))
+        {
+            return GetResult(response);
+        }
+
+        if (streaming == true)
+        {
+            return new ActorUpdateStreamingResult(responseHandle);
+        }
+
+        if (blocking == true)
+        {
+            response = await responseHandle.GetResponseAsync(cancellationToken);
+            return GetResult(response);
+        }
+
+        return Results.Ok(new ActorResponse
+        {
+            ActorId = actorId,
+            MessageId = messageId,
+            Status = RequestStatus.Pending,
+            Data = JsonDocument.Parse("{}").RootElement
+        });
+    }
+
+    public static async Task<IResult> SendRequestAsync(
+        string actorType,
+        string actorKey,
+        string messageId,
+        bool? blocking,
+        bool? streaming,
+        ActorRequest request,
+        IActorClient actorClient,
+        CancellationToken cancellationToken)
+    {
+        var responseHandle = await actorClient.SendRequestAsync(request, cancellationToken);
+        if (responseHandle.TryGetResponse(out var response))
+        {
+            return GetResult(response);
+        }
+
+        if (streaming == true)
+        {
+            return new ActorUpdateStreamingResult(responseHandle);
+        }
+
+        if (blocking == true)
+        {
+            response = await responseHandle.GetResponseAsync(cancellationToken);
+            return GetResult(response);
+        }
+
+        return Results.Accepted();
+    }
+
+    private static IResult GetResult(ActorResponse response)
+    {
+        if (response.Status == RequestStatus.NotFound)
+        {
+            return Results.NotFound();
+        }
+
+        return Results.Ok(response);
+    }
+
+    public static async Task<IResult> CancelRequestAsync(
+        string actorType,
+        string actorKey,
+        string messageId,
+        IActorClient actorClient,
+        CancellationToken cancellationToken)
+    {
+        var actorId = new ActorId(actorType, actorKey);
+        var responseHandle = await actorClient.GetResponseAsync(actorId, messageId, cancellationToken);
+
+        if (responseHandle.TryGetResponse(out var response))
+        {
+            if (response.Status is RequestStatus.NotFound)
+            {
+                return Results.NotFound();
+            }
+            else if (response.Status is RequestStatus.Completed or RequestStatus.Failed)
+            {
+                return Results.Conflict("The request has already completed and cannot be cancelled.");
+            }
+        }
+
+        await responseHandle.CancelAsync(cancellationToken);
+        return Results.NoContent();
+    }
+
+    private sealed class ActorUpdateStreamingResult(
+        ActorResponseHandle responseHandle) : IResult
+    {
+        public async Task ExecuteAsync(HttpContext httpContext)
+        {
+            var cancellationToken = httpContext.RequestAborted;
+            var response = httpContext.Response;
+            response.Headers.ContentType = "text/event-stream";
+            response.Headers.CacheControl = "no-cache,no-store";
+            response.Headers.Connection = "keep-alive";
+
+            // Make sure we disable all response buffering for SSE.
+            response.Headers.ContentEncoding = "identity";
+            httpContext.Features.GetRequiredFeature<IHttpResponseBodyFeature>().DisableBuffering();
+            await response.Body.FlushAsync(cancellationToken);
+
+            var updateTypeInfo = AgentHostingJsonUtilities.DefaultOptions.GetTypeInfo(typeof(ActorRequestUpdate));
+
+            await foreach (var update in responseHandle.WatchUpdatesAsync(cancellationToken).ConfigureAwait(false))
+            {
+                var eventData = JsonSerializer.Serialize(update, updateTypeInfo);
+                var eventText = $"data: {eventData}\n\n";
+
+                await response.WriteAsync(eventText, cancellationToken);
+                await response.Body.FlushAsync(cancellationToken);
+            }
+        }
+    }
+}