From 249a43c0e9963c00e13b12bb1b817e064dbd674e Mon Sep 17 00:00:00 2001 From: Jacob Alber Date: Thu, 19 Mar 2026 16:16:09 +0000 Subject: [PATCH] refactor: Remove instance-shared current agent tracking in handoffs Because the tracker was instance-shared between the start and end executors, it would be shared between all sessions, resulting in incorrect behaviour. The corect way to do this is to keep the data in a shared executor scope, which is per-session. --- .../AgentWorkflowBuilder.cs | 4 +-- .../HandoffsCurrentAgentTracker.cs | 9 ------ .../Specialized/HandoffsEndExecutor.cs | 10 +++++-- .../Specialized/HandoffsStartExecutor.cs | 28 +++++++++++++++++-- .../Sample/12_HandOff_HostAsAgent.cs | 4 +-- 5 files changed, 37 insertions(+), 18 deletions(-) delete mode 100644 dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsCurrentAgentTracker.cs diff --git a/dotnet/src/Microsoft.Agents.AI.Workflows/AgentWorkflowBuilder.cs b/dotnet/src/Microsoft.Agents.AI.Workflows/AgentWorkflowBuilder.cs index 501c7df230..22ee1b48eb 100644 --- a/dotnet/src/Microsoft.Agents.AI.Workflows/AgentWorkflowBuilder.cs +++ b/dotnet/src/Microsoft.Agents.AI.Workflows/AgentWorkflowBuilder.cs @@ -145,7 +145,7 @@ public static partial class AgentWorkflowBuilder return builder.Build(); } - /// Creates a new using as the starting agent in the workflow. + /// Creates a new using as the starting agent in the workflow. /// The agent that will receive inputs provided to the workflow. /// The builder for creating a workflow based on handoffs. /// @@ -154,7 +154,7 @@ public static partial class AgentWorkflowBuilder /// The must be capable of understanding those provided. If the agent /// ignores the tools or is otherwise unable to advertize them to the underlying provider, handoffs will not occur. /// - public static HandoffsWorkflowBuilder CreateHandoffBuilderWith(AIAgent initialAgent) + public static HandoffWorkflowBuilder CreateHandoffBuilderWith(AIAgent initialAgent) { Throw.IfNull(initialAgent); return new(initialAgent); diff --git a/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsCurrentAgentTracker.cs b/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsCurrentAgentTracker.cs deleted file mode 100644 index 51e3fd9475..0000000000 --- a/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsCurrentAgentTracker.cs +++ /dev/null @@ -1,9 +0,0 @@ -// Copyright (c) Microsoft. All rights reserved. - -namespace Microsoft.Agents.AI.Workflows.Specialized; - -/// Tracks the current agent ID across turns when return-to-previous routing is enabled. -internal sealed class HandoffsCurrentAgentTracker -{ - public string? CurrentAgentId { get; set; } -} diff --git a/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsEndExecutor.cs b/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsEndExecutor.cs index c892112453..4a43c00a72 100644 --- a/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsEndExecutor.cs +++ b/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsEndExecutor.cs @@ -8,7 +8,7 @@ using Microsoft.Extensions.AI; namespace Microsoft.Agents.AI.Workflows.Specialized; /// Executor used at the end of a handoff workflow to raise a final completed event. -internal sealed class HandoffsEndExecutor(HandoffsCurrentAgentTracker? tracker = null) : Executor(ExecutorId, declareCrossRunShareable: true), IResettableExecutor +internal sealed class HandoffsEndExecutor(bool returnToPrevious) : Executor(ExecutorId, declareCrossRunShareable: true), IResettableExecutor { public const string ExecutorId = "HandoffEnd"; @@ -19,9 +19,13 @@ internal sealed class HandoffsEndExecutor(HandoffsCurrentAgentTracker? tracker = private async ValueTask HandleAsync(HandoffState handoff, IWorkflowContext context, CancellationToken cancellationToken) { - if (tracker is not null && handoff.CurrentAgentId is not null) + if (returnToPrevious) { - tracker.CurrentAgentId = handoff.CurrentAgentId; + await context.QueueStateUpdateAsync(HandoffConstants.CurrentAgentTrackerKey, + handoff.CurrentAgentId, + HandoffConstants.CurrentAgentTrackerScope, + cancellationToken) + .ConfigureAwait(false); } await context.YieldOutputAsync(handoff.Messages, cancellationToken).ConfigureAwait(false); diff --git a/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsStartExecutor.cs b/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsStartExecutor.cs index 119a0a778d..87c3b4566b 100644 --- a/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsStartExecutor.cs +++ b/dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffsStartExecutor.cs @@ -7,8 +7,14 @@ using Microsoft.Extensions.AI; namespace Microsoft.Agents.AI.Workflows.Specialized; +internal static class HandoffConstants +{ + internal const string CurrentAgentTrackerKey = "LastAgentId"; + internal const string CurrentAgentTrackerScope = "HandoffOrchestration"; +} + /// Executor used at the start of a handoffs workflow to accumulate messages and emit them as HandoffState upon receiving a turn token. -internal sealed class HandoffsStartExecutor(HandoffsCurrentAgentTracker? tracker = null) : ChatProtocolExecutor(ExecutorId, DefaultOptions, declareCrossRunShareable: true), IResettableExecutor +internal sealed class HandoffsStartExecutor(bool returnToPrevious) : ChatProtocolExecutor(ExecutorId, DefaultOptions, declareCrossRunShareable: true), IResettableExecutor { internal const string ExecutorId = "HandoffStart"; @@ -22,7 +28,25 @@ internal sealed class HandoffsStartExecutor(HandoffsCurrentAgentTracker? tracker base.ConfigureProtocol(protocolBuilder).SendsMessage(); protected override ValueTask TakeTurnAsync(List messages, IWorkflowContext context, bool? emitEvents, CancellationToken cancellationToken = default) - => context.SendMessageAsync(new HandoffState(new(emitEvents), null, messages, tracker?.CurrentAgentId), cancellationToken: cancellationToken); + { + if (returnToPrevious) + { + return context.InvokeWithStateAsync( + async (string? currentAgentId, IWorkflowContext context, CancellationToken cancellationToken) => + { + HandoffState handoffState = new(new(emitEvents), null, messages, currentAgentId); + await context.SendMessageAsync(handoffState, cancellationToken).ConfigureAwait(false); + + return currentAgentId; + }, + HandoffConstants.CurrentAgentTrackerKey, + HandoffConstants.CurrentAgentTrackerScope, + cancellationToken); + } + + HandoffState handoff = new(new(emitEvents), null, messages); + return context.SendMessageAsync(handoff, cancellationToken); + } public new ValueTask ResetAsync() => base.ResetAsync(); } diff --git a/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/Sample/12_HandOff_HostAsAgent.cs b/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/Sample/12_HandOff_HostAsAgent.cs index 3d88ed22ab..993a6d462b 100644 --- a/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/Sample/12_HandOff_HostAsAgent.cs +++ b/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/Sample/12_HandOff_HostAsAgent.cs @@ -20,7 +20,7 @@ internal sealed class HandoffTestEchoAgent(string id, string name, string prefix { IEnumerable? handoffs = chatClientOptions.ChatOptions .Tools? - .Where(tool => tool.Name?.StartsWith(HandoffsWorkflowBuilder.FunctionPrefix, + .Where(tool => tool.Name?.StartsWith(HandoffWorkflowBuilder.FunctionPrefix, StringComparison.OrdinalIgnoreCase) is true); if (handoffs != null) @@ -58,7 +58,7 @@ internal static class Step12EntryPoint .Select(i => new HandoffTestEchoAgent($"{EchoAgentIdPrefix}{i}", $"{EchoAgentNamePrefix}{i}", EchoPrefixForAgent(i))) .ToArray(); - return new HandoffsWorkflowBuilder(echoAgents[0]) + return new HandoffWorkflowBuilder(echoAgents[0]) .WithHandoff(echoAgents[0], echoAgents[1]) .Build(); }