.NET: [BREAKING] Rename AgentThread to AgentSession

dotnet/samples/A2AClientServer/A2AClient/Program.cs

@@ -42,7 +42,7 @@ private static async Task HandleCommandsAsync(CancellationToken cancellationToke
         // Create the Host agent
         var hostAgent = new HostClientAgent(loggerFactory);
         await hostAgent.InitializeAgentAsync(modelId, apiKey, agentUrls!.Split(";"));
-        AgentThread thread = await hostAgent.Agent!.GetNewThreadAsync(cancellationToken);
+        AgentSession session = await hostAgent.Agent!.GetNewSessionAsync(cancellationToken);
         try
         {
             while (true)
@@ -61,7 +61,7 @@ private static async Task HandleCommandsAsync(CancellationToken cancellationToke
                     break;
                 }
 
-                var agentResponse = await hostAgent.Agent!.RunAsync(message, thread, cancellationToken: cancellationToken);
+                var agentResponse = await hostAgent.Agent!.RunAsync(message, session, cancellationToken: cancellationToken);
                 foreach (var chatMessage in agentResponse.Messages)
                 {
                     Console.ForegroundColor = ConsoleColor.Cyan;

dotnet/samples/AGUIClientServer/AGUIClient/Program.cs

@@ -88,7 +88,7 @@ private static async Task HandleCommandsAsync(CancellationToken cancellationToke
             description: "AG-UI Client Agent",
             tools: [changeBackground, readClientClimateSensors]);
 
-        AgentThread thread = await agent.GetNewThreadAsync(cancellationToken);
+        AgentSession session = await agent.GetNewSessionAsync(cancellationToken);
         List<ChatMessage> messages = [new(ChatRole.System, "You are a helpful assistant.")];
         try
         {
@@ -112,23 +112,23 @@ private static async Task HandleCommandsAsync(CancellationToken cancellationToke
 
                 // Call RunStreamingAsync to get streaming updates
                 bool isFirstUpdate = true;
-                string? threadId = null;
+                string? sessionId = null;
                 var updates = new List<ChatResponseUpdate>();
-                await foreach (AgentResponseUpdate update in agent.RunStreamingAsync(messages, thread, cancellationToken: cancellationToken))
+                await foreach (AgentResponseUpdate update in agent.RunStreamingAsync(messages, session, cancellationToken: cancellationToken))
                 {
                     // Use AsChatResponseUpdate to access ChatResponseUpdate properties
                     ChatResponseUpdate chatUpdate = update.AsChatResponseUpdate();
                     updates.Add(chatUpdate);
                     if (chatUpdate.ConversationId != null)
                     {
-                        threadId = chatUpdate.ConversationId;
+                        sessionId = chatUpdate.ConversationId;
                     }
 
                     // Display run started information from the first update
-                    if (isFirstUpdate && threadId != null && update.ResponseId != null)
+                    if (isFirstUpdate && sessionId != null && update.ResponseId != null)
                     {
                         Console.ForegroundColor = ConsoleColor.Yellow;
-                        Console.WriteLine($"\n[Run Started - Thread: {threadId}, Run: {update.ResponseId}]");
+                        Console.WriteLine($"\n[Run Started - Session: {sessionId}, Run: {update.ResponseId}]");
                         Console.ResetColor();
                         isFirstUpdate = false;
                     }
@@ -177,7 +177,7 @@ private static async Task HandleCommandsAsync(CancellationToken cancellationToke
                     var lastUpdate = updates[^1];
                     Console.ForegroundColor = ConsoleColor.Yellow;
                     Console.WriteLine();
-                    Console.WriteLine($"[Run Ended - Thread: {threadId}, Run: {lastUpdate.ResponseId}]");
+                    Console.WriteLine($"[Run Ended - Session: {sessionId}, Run: {lastUpdate.ResponseId}]");
                     Console.ResetColor();
                 }
                 messages.Clear();

dotnet/samples/AGUIClientServer/AGUIDojoServer/AgenticUI/AgenticUIAgent.cs

@@ -19,21 +19,21 @@ public AgenticUIAgent(AIAgent innerAgent, JsonSerializerOptions jsonSerializerOp
         this._jsonSerializerOptions = jsonSerializerOptions;
     }
 
-    protected override Task<AgentResponse> RunCoreAsync(IEnumerable<ChatMessage> messages, AgentThread? thread = null, AgentRunOptions? options = null, CancellationToken cancellationToken = default)
+    protected override Task<AgentResponse> RunCoreAsync(IEnumerable<ChatMessage> messages, AgentSession? session = null, AgentRunOptions? options = null, CancellationToken cancellationToken = default)
     {
-        return this.RunCoreStreamingAsync(messages, thread, options, cancellationToken).ToAgentResponseAsync(cancellationToken);
+        return this.RunCoreStreamingAsync(messages, session, options, cancellationToken).ToAgentResponseAsync(cancellationToken);
     }
 
     protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingAsync(
         IEnumerable<ChatMessage> messages,
-        AgentThread? thread = null,
+        AgentSession? session = null,
         AgentRunOptions? options = null,
         [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
         // Track function calls that should trigger state events
         var trackedFunctionCalls = new Dictionary<string, FunctionCallContent>();
 
-        await foreach (var update in this.InnerAgent.RunStreamingAsync(messages, thread, options, cancellationToken).ConfigureAwait(false))
+        await foreach (var update in this.InnerAgent.RunStreamingAsync(messages, session, options, cancellationToken).ConfigureAwait(false))
         {
             // Process contents: track function calls and emit state events for results
             List<AIContent> stateEventsToEmit = new();

dotnet/samples/AGUIClientServer/AGUIDojoServer/PredictiveStateUpdates/PredictiveStateUpdatesAgent.cs

@@ -20,21 +20,21 @@ public PredictiveStateUpdatesAgent(AIAgent innerAgent, JsonSerializerOptions jso
         this._jsonSerializerOptions = jsonSerializerOptions;
     }
 
-    protected override Task<AgentResponse> RunCoreAsync(IEnumerable<ChatMessage> messages, AgentThread? thread = null, AgentRunOptions? options = null, CancellationToken cancellationToken = default)
+    protected override Task<AgentResponse> RunCoreAsync(IEnumerable<ChatMessage> messages, AgentSession? session = null, AgentRunOptions? options = null, CancellationToken cancellationToken = default)
     {
-        return this.RunCoreStreamingAsync(messages, thread, options, cancellationToken).ToAgentResponseAsync(cancellationToken);
+        return this.RunCoreStreamingAsync(messages, session, options, cancellationToken).ToAgentResponseAsync(cancellationToken);
     }
 
     protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingAsync(
         IEnumerable<ChatMessage> messages,
-        AgentThread? thread = null,
+        AgentSession? session = null,
         AgentRunOptions? options = null,
         [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
         // Track the last emitted document state to avoid duplicates
         string? lastEmittedDocument = null;
 
-        await foreach (var update in this.InnerAgent.RunStreamingAsync(messages, thread, options, cancellationToken).ConfigureAwait(false))
+        await foreach (var update in this.InnerAgent.RunStreamingAsync(messages, session, options, cancellationToken).ConfigureAwait(false))
         {
             // Check if we're seeing a write_document tool call and emit predictive state
             bool hasToolCall = false;

dotnet/samples/AGUIClientServer/AGUIDojoServer/SharedState/SharedStateAgent.cs

@@ -19,21 +19,21 @@ public SharedStateAgent(AIAgent innerAgent, JsonSerializerOptions jsonSerializer
         this._jsonSerializerOptions = jsonSerializerOptions;
     }
 
-    protected override Task<AgentResponse> RunCoreAsync(IEnumerable<ChatMessage> messages, AgentThread? thread = null, AgentRunOptions? options = null, CancellationToken cancellationToken = default)
+    protected override Task<AgentResponse> RunCoreAsync(IEnumerable<ChatMessage> messages, AgentSession? session = null, AgentRunOptions? options = null, CancellationToken cancellationToken = default)
     {
-        return this.RunCoreStreamingAsync(messages, thread, options, cancellationToken).ToAgentResponseAsync(cancellationToken);
+        return this.RunCoreStreamingAsync(messages, session, options, cancellationToken).ToAgentResponseAsync(cancellationToken);
     }
 
     protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingAsync(
         IEnumerable<ChatMessage> messages,
-        AgentThread? thread = null,
+        AgentSession? session = null,
         AgentRunOptions? options = null,
         [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
         if (options is not ChatClientAgentRunOptions { ChatOptions.AdditionalProperties: { } properties } chatRunOptions ||
             !properties.TryGetValue("ag_ui_state", out JsonElement state))
         {
-            await foreach (var update in this.InnerAgent.RunStreamingAsync(messages, thread, options, cancellationToken).ConfigureAwait(false))
+            await foreach (var update in this.InnerAgent.RunStreamingAsync(messages, session, options, cancellationToken).ConfigureAwait(false))
             {
                 yield return update;
             }
@@ -64,7 +64,7 @@ protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingA
         var firstRunMessages = messages.Append(stateUpdateMessage);
 
         var allUpdates = new List<AgentResponseUpdate>();
-        await foreach (var update in this.InnerAgent.RunStreamingAsync(firstRunMessages, thread, firstRunOptions, cancellationToken).ConfigureAwait(false))
+        await foreach (var update in this.InnerAgent.RunStreamingAsync(firstRunMessages, session, firstRunOptions, cancellationToken).ConfigureAwait(false))
         {
             allUpdates.Add(update);
 
@@ -98,7 +98,7 @@ protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingA
                 ChatRole.System,
                 [new TextContent("Please provide a concise summary of the state changes in at most two sentences.")]));
 
-        await foreach (var update in this.InnerAgent.RunStreamingAsync(secondRunMessages, thread, options, cancellationToken).ConfigureAwait(false))
+        await foreach (var update in this.InnerAgent.RunStreamingAsync(secondRunMessages, session, options, cancellationToken).ConfigureAwait(false))
         {
             yield return update;
         }

dotnet/samples/AgentWebChat/AgentWebChat.AgentHost/Program.cs

@@ -36,7 +36,7 @@
     chatClientServiceKey: "chat-model")
     .WithAITool(new CustomAITool())
     .WithAITool(new CustomFunctionTool())
-    .WithInMemoryThreadStore();
+    .WithInMemorySessionStore();
 
 var knightsKnavesAgentBuilder = builder.AddAIAgent("knights-and-knaves", (sp, key) =>
 {

dotnet/samples/AgentWebChat/AgentWebChat.Web/A2AAgentClient.cs

@@ -28,13 +28,13 @@ public A2AAgentClient(ILogger logger, Uri baseUri)
     public override async IAsyncEnumerable<AgentResponseUpdate> RunStreamingAsync(
         string agentName,
         IList<ChatMessage> messages,
-        string? threadId = null,
+        string? sessionId = null,
         [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
         this._logger.LogInformation("Running agent {AgentName} with {MessageCount} messages via A2A", agentName, messages.Count);
 
         var (a2aClient, _) = this.ResolveClient(agentName);
-        var contextId = threadId ?? Guid.NewGuid().ToString("N");
+        var contextId = sessionId ?? Guid.NewGuid().ToString("N");
 
         // Convert and send messages via A2A without try-catch in yield method
         var results = new List<AgentResponseUpdate>();

dotnet/samples/AgentWebChat/AgentWebChat.Web/IAgentClient.cs

@@ -16,13 +16,13 @@ internal abstract class AgentClientBase
     /// </summary>
     /// <param name="agentName">The name of the agent to run.</param>
     /// <param name="messages">The messages to send to the agent.</param>
-    /// <param name="threadId">Optional thread identifier for conversation continuity.</param>
+    /// <param name="sessionId">Optional session identifier for conversation continuity.</param>
     /// <param name="cancellationToken">Cancellation token.</param>
     /// <returns>An asynchronous enumerable of agent response updates.</returns>
     public abstract IAsyncEnumerable<AgentResponseUpdate> RunStreamingAsync(
         string agentName,
         IList<ChatMessage> messages,
-        string? threadId = null,
+        string? sessionId = null,
         CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -34,16 +34,3 @@ public abstract IAsyncEnumerable<AgentResponseUpdate> RunStreamingAsync(
     public virtual Task<AgentCard?> GetAgentCardAsync(string agentName, CancellationToken cancellationToken = default)
         => Task.FromResult<AgentCard?>(null);
 }
-
-/// <summary>
-/// Helper class to create a thread-like wrapper for agent clients.
-/// </summary>
-public class AgentClientThread
-{
-    public string ThreadId { get; }
-
-    public AgentClientThread(string? threadId = null)
-    {
-        this.ThreadId = threadId ?? Guid.NewGuid().ToString("N");
-    }
-}

dotnet/samples/AgentWebChat/AgentWebChat.Web/OpenAIChatCompletionsAgentClient.cs

@@ -19,7 +19,7 @@ internal sealed class OpenAIChatCompletionsAgentClient(HttpClient httpClient) :
     public override async IAsyncEnumerable<AgentResponseUpdate> RunStreamingAsync(
         string agentName,
         IList<ChatMessage> messages,
-        string? threadId = null,
+        string? sessionId = null,
         [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
         OpenAIClientOptions options = new()

dotnet/samples/AgentWebChat/AgentWebChat.Web/OpenAIResponsesAgentClient.cs

@@ -18,7 +18,7 @@ internal sealed class OpenAIResponsesAgentClient(HttpClient httpClient) : AgentC
     public override async IAsyncEnumerable<AgentResponseUpdate> RunStreamingAsync(
         string agentName,
         IList<ChatMessage> messages,
-        string? threadId = null,
+        string? sessionId = null,
         [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
         OpenAIClientOptions options = new()
@@ -30,7 +30,7 @@ public override async IAsyncEnumerable<AgentResponseUpdate> RunStreamingAsync(
         var openAiClient = new ResponsesClient(model: agentName, credential: new ApiKeyCredential("dummy-key"), options: options).AsIChatClient();
         var chatOptions = new ChatOptions()
         {
-            ConversationId = threadId
+            ConversationId = sessionId
         };
 
         await foreach (var update in openAiClient.GetStreamingResponseAsync(messages, chatOptions, cancellationToken: cancellationToken))

dotnet/samples/AzureFunctions/02_AgentOrchestration_Chaining/FunctionTriggers.cs

@@ -19,15 +19,15 @@ public sealed record TextResponse(string Text);
     public static async Task<string> RunOrchestrationAsync([OrchestrationTrigger] TaskOrchestrationContext context)
     {
         DurableAIAgent writer = context.GetAgent("WriterAgent");
-        AgentThread writerThread = await writer.GetNewThreadAsync();
+        AgentSession writerSession = await writer.GetNewSessionAsync();
 
         AgentResponse<TextResponse> initial = await writer.RunAsync<TextResponse>(
             message: "Write a concise inspirational sentence about learning.",
-            thread: writerThread);
+            session: writerSession);
 
         AgentResponse<TextResponse> refined = await writer.RunAsync<TextResponse>(
             message: $"Improve this further while keeping it under 25 words: {initial.Result.Text}",
-            thread: writerThread);
+            session: writerSession);
 
         return refined.Result.Text;
     }

dotnet/samples/AzureFunctions/02_AgentOrchestration_Chaining/Program.cs

@@ -21,7 +21,7 @@
     ? new AzureOpenAIClient(new Uri(endpoint), new AzureKeyCredential(azureOpenAiKey))
     : new AzureOpenAIClient(new Uri(endpoint), new AzureCliCredential());
 
-// Single agent used by the orchestration to demonstrate sequential calls on the same thread.
+// Single agent used by the orchestration to demonstrate sequential calls on the same session.
 const string WriterName = "WriterAgent";
 const string WriterInstructions =
     """

dotnet/samples/AzureFunctions/02_AgentOrchestration_Chaining/README.md

@@ -1,11 +1,11 @@
 # Single Agent Orchestration Sample
 
-This sample demonstrates how to use the Durable Agent Framework (DAFx) to create a simple Azure Functions app that orchestrates sequential calls to a single AI agent using the same conversation thread for context continuity.
+This sample demonstrates how to use the Durable Agent Framework (DAFx) to create a simple Azure Functions app that orchestrates sequential calls to a single AI agent using the same session for context continuity.
 
 ## Key Concepts Demonstrated
 
 - Orchestrating multiple interactions with the same agent in a deterministic order
-- Using the same `AgentThread` across multiple calls to maintain conversational context
+- Using the same `AgentSession` across multiple calls to maintain conversational context
 - Durable orchestration with automatic checkpointing and resumption from failures
 - HTTP API integration for starting and monitoring orchestrations
 

dotnet/samples/AzureFunctions/04_AgentOrchestration_Conditionals/FunctionTriggers.cs

@@ -21,7 +21,7 @@ public static async Task<string> RunOrchestrationAsync([OrchestrationTrigger] Ta
 
         // Get the spam detection agent
         DurableAIAgent spamDetectionAgent = context.GetAgent("SpamDetectionAgent");
-        AgentThread spamThread = await spamDetectionAgent.GetNewThreadAsync();
+        AgentSession spamSession = await spamDetectionAgent.GetNewSessionAsync();
 
         // Step 1: Check if the email is spam
         AgentResponse<DetectionResult> spamDetectionResponse = await spamDetectionAgent.RunAsync<DetectionResult>(
@@ -31,7 +31,7 @@ public static async Task<string> RunOrchestrationAsync([OrchestrationTrigger] Ta
                 Email ID: {email.EmailId}
                 Content: {email.EmailContent}
                 """,
-            thread: spamThread);
+            session: spamSession);
         DetectionResult result = spamDetectionResponse.Result;
 
         // Step 2: Conditional logic based on spam detection result
@@ -43,7 +43,7 @@ public static async Task<string> RunOrchestrationAsync([OrchestrationTrigger] Ta
 
         // Generate and send response for legitimate email
         DurableAIAgent emailAssistantAgent = context.GetAgent("EmailAssistantAgent");
-        AgentThread emailThread = await emailAssistantAgent.GetNewThreadAsync();
+        AgentSession emailSession = await emailAssistantAgent.GetNewSessionAsync();
 
         AgentResponse<EmailResponse> emailAssistantResponse = await emailAssistantAgent.RunAsync<EmailResponse>(
             message:
@@ -53,7 +53,7 @@ public static async Task<string> RunOrchestrationAsync([OrchestrationTrigger] Ta
                     Email ID: {email.EmailId}
                     Content: {email.EmailContent}
                     """,
-            thread: emailThread);
+            session: emailSession);
 
         EmailResponse emailResponse = emailAssistantResponse.Result;
 

dotnet/samples/AzureFunctions/05_AgentOrchestration_HITL/FunctionTriggers.cs

@@ -24,15 +24,15 @@ public static async Task<object> RunOrchestrationAsync(
 
         // Get the writer agent
         DurableAIAgent writerAgent = context.GetAgent("WriterAgent");
-        AgentThread writerThread = await writerAgent.GetNewThreadAsync();
+        AgentSession writerSession = await writerAgent.GetNewSessionAsync();
 
         // Set initial status
         context.SetCustomStatus($"Starting content generation for topic: {input.Topic}");
 
         // Step 1: Generate initial content
         AgentResponse<GeneratedContent> writerResponse = await writerAgent.RunAsync<GeneratedContent>(
             message: $"Write a short article about '{input.Topic}'.",
-            thread: writerThread);
+            session: writerSession);
         GeneratedContent content = writerResponse.Result;
 
         // Human-in-the-loop iteration - we set a maximum number of attempts to avoid infinite loops
@@ -81,7 +81,7 @@ The content was rejected by a human reviewer. Please rewrite the article incorpo
 
                     Human Feedback: {humanResponse.Feedback}
                     """,
-                thread: writerThread);
+                session: writerSession);
 
             content = writerResponse.Result;
         }