From 1432d0ac312990d3ebb20195b9ace5b859afe73e Mon Sep 17 00:00:00 2001
From: Chris Dai <67849861+chrisdaiii@users.noreply.github.com>
Date: Thu, 22 Jan 2026 15:36:40 +0800
Subject: [PATCH] Update AGUIEndpointRouteBuilderExtensions.cs

Extend agent dynamic creation support
---
 .../AGUIEndpointRouteBuilderExtensions.cs     | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/dotnet/src/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore/AGUIEndpointRouteBuilderExtensions.cs b/dotnet/src/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore/AGUIEndpointRouteBuilderExtensions.cs
index e20d1ab448..52b015eb52 100644
--- a/dotnet/src/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore/AGUIEndpointRouteBuilderExtensions.cs
+++ b/dotnet/src/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore/AGUIEndpointRouteBuilderExtensions.cs
@@ -80,4 +80,66 @@ public static IEndpointConventionBuilder MapAGUI(
             return new AGUIServerSentEventsResult(events, sseLogger);
         });
     }
+
+    /// <summary>
+    /// Maps an AG-UI agent endpoint.
+    /// </summary>
+    /// <param name="endpoints">The endpoint route builder.</param>
+    /// <param name="pattern">The URL pattern for the endpoint.</param>
+    /// <param name="aiAgentFactory">The factory that creates agent instance.</param>
+    /// <returns>An <see cref="IEndpointConventionBuilder"/> for the mapped endpoint.</returns>
+    public static IEndpointConventionBuilder MapAGUI(
+        this IEndpointRouteBuilder endpoints,
+        [StringSyntax("route")] string pattern,
+        Func<HttpContext, AIAgent> aiAgentFactory)
+    {
+        return endpoints.MapPost(pattern, async ([FromBody] RunAgentInput? input, HttpContext context, CancellationToken cancellationToken) =>
+        {
+            if (input is null)
+            {
+                return Results.BadRequest();
+            }
+
+            var jsonOptions = context.RequestServices.GetRequiredService<IOptions<Microsoft.AspNetCore.Http.Json.JsonOptions>>();
+            var jsonSerializerOptions = jsonOptions.Value.SerializerOptions;
+
+            var messages = input.Messages.AsChatMessages(jsonSerializerOptions);
+            var clientTools = input.Tools?.AsAITools().ToList();
+
+            // Create run options with AG-UI context in AdditionalProperties
+            var runOptions = new ChatClientAgentRunOptions
+            {
+                ChatOptions = new ChatOptions
+                {
+                    Tools = clientTools,
+                    AdditionalProperties = new AdditionalPropertiesDictionary
+                    {
+                        ["ag_ui_state"] = input.State,
+                        ["ag_ui_context"] = input.Context?.Select(c => new KeyValuePair<string, string>(c.Description, c.Value)).ToArray(),
+                        ["ag_ui_forwarded_properties"] = input.ForwardedProperties,
+                        ["ag_ui_thread_id"] = input.ThreadId,
+                        ["ag_ui_run_id"] = input.RunId
+                    }
+                }
+            };
+
+            var aiAgent = aiAgentFactory(context);
+            
+            // Run the agent and convert to AG-UI events
+            var events = aiAgent.RunStreamingAsync(
+                messages,
+                options: runOptions,
+                cancellationToken: cancellationToken)
+                .AsChatResponseUpdatesAsync()
+                .FilterServerToolsFromMixedToolInvocationsAsync(clientTools, cancellationToken)
+                .AsAGUIEventStreamAsync(
+                    input.ThreadId,
+                    input.RunId,
+                    jsonSerializerOptions,
+                    cancellationToken);
+
+            var sseLogger = context.RequestServices.GetRequiredService<ILogger<AGUIServerSentEventsResult>>();
+            return new AGUIServerSentEventsResult(events, sseLogger);
+        });
+    }
 }