Merge branch 'main' into feat/durable_task

dotnet/src/Microsoft.Agents.AI.A2A/A2AAgent.cs

@@ -127,6 +127,7 @@ public sealed class A2AAgent : AIAgent
             {
                 AgentId = this.Id,
                 ResponseId = message.MessageId,
+                FinishReason = ChatFinishReason.Stop,
                 RawRepresentation = message,
                 Messages = [message.ToChatMessage()],
                 AdditionalProperties = message.Metadata?.ToAdditionalProperties(),
@@ -141,6 +142,7 @@ public sealed class A2AAgent : AIAgent
             {
                 AgentId = this.Id,
                 ResponseId = agentTask.Id,
+                FinishReason = MapTaskStateToFinishReason(agentTask.Status.State),
                 RawRepresentation = agentTask,
                 Messages = agentTask.ToChatMessages() ?? [],
                 ContinuationToken = CreateContinuationToken(agentTask.Id, agentTask.Status.State),
@@ -328,6 +330,7 @@ public sealed class A2AAgent : AIAgent
         {
             AgentId = this.Id,
             ResponseId = message.MessageId,
+            FinishReason = ChatFinishReason.Stop,
             RawRepresentation = message,
             Role = ChatRole.Assistant,
             MessageId = message.MessageId,
@@ -342,6 +345,7 @@ public sealed class A2AAgent : AIAgent
         {
             AgentId = this.Id,
             ResponseId = task.Id,
+            FinishReason = MapTaskStateToFinishReason(task.Status.State),
             RawRepresentation = task,
             Role = ChatRole.Assistant,
             Contents = task.ToAIContents(),
@@ -365,7 +369,16 @@ public sealed class A2AAgent : AIAgent
             responseUpdate.Contents = artifactUpdateEvent.Artifact.ToAIContents();
             responseUpdate.RawRepresentation = artifactUpdateEvent;
         }
+        else if (taskUpdateEvent is TaskStatusUpdateEvent statusUpdateEvent)
+        {
+            responseUpdate.FinishReason = MapTaskStateToFinishReason(statusUpdateEvent.Status.State);
+        }
 
         return responseUpdate;
     }
+
+    private static ChatFinishReason? MapTaskStateToFinishReason(TaskState state)
+    {
+        return state == TaskState.Completed ? ChatFinishReason.Stop : null;
+    }
 }

dotnet/src/Microsoft.Agents.AI.Abstractions/AgentResponse.cs

@@ -61,6 +61,7 @@ public class AgentResponse
 
         this.AdditionalProperties = response.AdditionalProperties;
         this.CreatedAt = response.CreatedAt;
+        this.FinishReason = response.FinishReason;
         this.Messages = response.Messages;
         this.RawRepresentation = response;
         this.ResponseId = response.ResponseId;
@@ -84,6 +85,7 @@ public class AgentResponse
 
         this.AdditionalProperties = response.AdditionalProperties;
         this.CreatedAt = response.CreatedAt;
+        this.FinishReason = response.FinishReason;
         this.Messages = response.Messages;
         this.RawRepresentation = response;
         this.ResponseId = response.ResponseId;
@@ -190,6 +192,21 @@ public class AgentResponse
     /// </remarks>
     public DateTimeOffset? CreatedAt { get; set; }
 
+    /// <summary>
+    /// Gets or sets the reason for the agent response finishing.
+    /// </summary>
+    /// <value>
+    /// A <see cref="ChatFinishReason"/> value indicating why the response finished (e.g., stop, length, content filter, tool calls),
+    /// or <see langword="null"/> if the finish reason is not available.
+    /// </value>
+    /// <remarks>
+    /// <para>
+    /// This property is particularly useful for detecting non-normal completions, such as content filtering
+    /// or token limit truncation, which may require special handling by the caller.
+    /// </para>
+    /// </remarks>
+    public ChatFinishReason? FinishReason { get; set; }
+
     /// <summary>
     /// Gets or sets the resource usage information for generating this response.
     /// </summary>
@@ -276,6 +293,7 @@ public class AgentResponse
                 RawRepresentation = message.RawRepresentation,
                 Role = message.Role,
 
+                FinishReason = this.FinishReason,
                 AgentId = this.AgentId,
                 ResponseId = this.ResponseId,
                 MessageId = message.MessageId,

dotnet/src/Microsoft.Agents.AI.Abstractions/AgentResponseExtensions.cs

@@ -38,6 +38,7 @@ public static class AgentResponseExtensions
             {
                 AdditionalProperties = response.AdditionalProperties,
                 CreatedAt = response.CreatedAt,
+                FinishReason = response.FinishReason,
                 Messages = response.Messages,
                 RawRepresentation = response,
                 ResponseId = response.ResponseId,
@@ -71,6 +72,7 @@ public static class AgentResponseExtensions
                 AuthorName = responseUpdate.AuthorName,
                 Contents = responseUpdate.Contents,
                 CreatedAt = responseUpdate.CreatedAt,
+                FinishReason = responseUpdate.FinishReason,
                 MessageId = responseUpdate.MessageId,
                 RawRepresentation = responseUpdate,
                 ResponseId = responseUpdate.ResponseId,

dotnet/src/Microsoft.Agents.AI.Abstractions/AgentResponseUpdate.cs

@@ -70,6 +70,7 @@ public class AgentResponseUpdate
         this.AuthorName = chatResponseUpdate.AuthorName;
         this.Contents = chatResponseUpdate.Contents;
         this.CreatedAt = chatResponseUpdate.CreatedAt;
+        this.FinishReason = chatResponseUpdate.FinishReason;
         this.MessageId = chatResponseUpdate.MessageId;
         this.RawRepresentation = chatResponseUpdate;
         this.ResponseId = chatResponseUpdate.ResponseId;
@@ -153,6 +154,15 @@ public class AgentResponseUpdate
     /// </remarks>
     public ResponseContinuationToken? ContinuationToken { get; set; }
 
+    /// <summary>
+    /// Gets or sets the reason for the agent response finishing.
+    /// </summary>
+    /// <value>
+    /// A <see cref="ChatFinishReason"/> value indicating why the response finished (e.g., stop, length, content filter, tool calls),
+    /// or <see langword="null"/> if the finish reason is not available or not yet determined (mid-stream).
+    /// </value>
+    public ChatFinishReason? FinishReason { get; set; }
+
     /// <inheritdoc/>
     public override string ToString() => this.Text;
 

dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/ChatCompletions/AIAgentChatCompletionsProcessor.cs

@@ -72,9 +72,7 @@ internal static class AIAgentChatCompletionsProcessor
 
             await foreach (var agentResponseUpdate in agent.RunStreamingAsync(chatMessages, options: options, cancellationToken: cancellationToken).WithCancellation(cancellationToken))
             {
-                var finishReason = (agentResponseUpdate.RawRepresentation is ChatResponseUpdate { FinishReason: not null } chatResponseUpdate)
-                    ? chatResponseUpdate.FinishReason.ToString()
-                    : "stop";
+                var finishReason = agentResponseUpdate.FinishReason?.ToString() ?? "stop";
 
                 var choiceChunks = new List<ChatCompletionChoiceChunk>();
                 CompletionUsage? usageDetails = null;

dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/ChatCompletions/AgentResponseExtensions.cs

@@ -34,9 +34,7 @@ internal static class AgentResponseExtensions
         var chatCompletionChoices = new List<ChatCompletionChoice>();
         var index = 0;
 
-        var finishReason = (agentResponse.RawRepresentation is ChatResponse { FinishReason: not null } chatResponse)
-            ? chatResponse.FinishReason.ToString()
-            : "stop"; // "stop" is a natural stop point; returning this by-default
+        var finishReason = agentResponse.FinishReason?.ToString() ?? ChatFinishReason.Stop.Value; // "stop" is a natural stop point; returning this by-default
 
         foreach (var message in agentResponse.Messages)
         {

dotnet/src/Microsoft.Agents.AI.Workflows/MessageMerger.cs

@@ -124,6 +124,7 @@ internal sealed class MessageMerger
         List<ChatMessage> messages = [];
         Dictionary<string, AgentResponse> responses = [];
         HashSet<string> agentIds = [];
+        HashSet<ChatFinishReason> finishReasons = [];
 
         foreach (string responseId in this._mergeStates.Keys)
         {
@@ -156,6 +157,11 @@ internal sealed class MessageMerger
                 createdTimes.Add(response.CreatedAt.Value);
             }
 
+            if (response.FinishReason.HasValue)
+            {
+                finishReasons.Add(response.FinishReason.Value);
+            }
+
             usage = MergeUsage(usage, response.Usage);
             additionalProperties = MergeProperties(additionalProperties, response.AdditionalProperties);
         }
@@ -182,6 +188,7 @@ internal sealed class MessageMerger
             AgentId = primaryAgentId
                    ?? primaryAgentName
                    ?? (agentIds.Count == 1 ? agentIds.First() : null),
+            FinishReason = finishReasons.Count == 1 ? finishReasons.First() : null,
             CreatedAt = DateTimeOffset.UtcNow,
             Usage = usage,
             AdditionalProperties = additionalProperties
@@ -207,6 +214,7 @@ internal sealed class MessageMerger
                 AgentId = incoming.AgentId ?? current.AgentId,
                 AdditionalProperties = MergeProperties(current.AdditionalProperties, incoming.AdditionalProperties),
                 CreatedAt = incoming.CreatedAt ?? current.CreatedAt,
+                FinishReason = incoming.FinishReason ?? current.FinishReason,
                 Messages = current.Messages.Concat(incoming.Messages).ToList(),
                 ResponseId = current.ResponseId,
                 RawRepresentation = rawRepresentation,