Rename ChatThreadId to ConversationId

src/Libraries/Microsoft.Extensions.AI.Abstractions/ChatCompletion/ChatOptions.cs

@@ -9,8 +9,8 @@ namespace Microsoft.Extensions.AI;
 /// <summary>Represents the options for a chat request.</summary>
 public class ChatOptions
 {
-    /// <summary>Gets or sets an optional identifier used to associate a request with an existing chat thread.</summary>
-    public string? ChatThreadId { get; set; }
+    /// <summary>Gets or sets an optional identifier used to associate a request with an existing conversation.</summary>
+    public string? ConversationId { get; set; }
 
     /// <summary>Gets or sets the temperature for generating chat responses.</summary>
     /// <remarks>
@@ -105,7 +105,7 @@ public virtual ChatOptions Clone()
     {
         ChatOptions options = new()
         {
-            ChatThreadId = ChatThreadId,
+            ConversationId = ConversationId,
             Temperature = Temperature,
             MaxOutputTokens = MaxOutputTokens,
             TopP = TopP,

src/Libraries/Microsoft.Extensions.AI.Abstractions/ChatCompletion/ChatResponse.cs

@@ -63,15 +63,17 @@ public IList<ChatMessage> Messages
     /// <summary>Gets or sets the ID of the chat response.</summary>
     public string? ResponseId { get; set; }
 
-    /// <summary>Gets or sets the chat thread ID associated with this chat response.</summary>
+    /// <summary>Gets or sets an identifier for the state of the conversation.</summary>
     /// <remarks>
-    /// Some <see cref="IChatClient"/> implementations are capable of storing the state for a chat thread, such that
+    /// Some <see cref="IChatClient"/> implementations are capable of storing the state for a conversation, such that
     /// the input messages supplied to <see cref="IChatClient.GetResponseAsync"/> need only be the additional messages beyond
     /// what's already stored. If this property is non-<see langword="null"/>, it represents an identifier for that state,
-    /// and it should be used in a subsequent <see cref="ChatOptions.ChatThreadId"/> instead of supplying the same messages
-    /// (and this <see cref="ChatResponse"/>'s message) as part of the <c>messages</c> parameter.
+    /// and it should be used in a subsequent <see cref="ChatOptions.ConversationId"/> instead of supplying the same messages
+    /// (and this <see cref="ChatResponse"/>'s message) as part of the <c>messages</c> parameter. Note that the value may
+    /// or may not differ on every response, depending on whether the underlying provider uses a fixed ID for each conversation
+    /// or updates it for each message.
     /// </remarks>
-    public string? ChatThreadId { get; set; }
+    public string? ConversationId { get; set; }
 
     /// <summary>Gets or sets the model ID used in the creation of the chat response.</summary>
     public string? ModelId { get; set; }
@@ -127,7 +129,7 @@ public ChatResponseUpdate[] ToChatResponseUpdates()
             ChatMessage message = _messages![i];
             updates[i] = new ChatResponseUpdate
             {
-                ChatThreadId = ChatThreadId,
+                ConversationId = ConversationId,
 
                 AdditionalProperties = message.AdditionalProperties,
                 AuthorName = message.AuthorName,

src/Libraries/Microsoft.Extensions.AI.Abstractions/ChatCompletion/ChatResponseExtensions.cs

@@ -320,9 +320,9 @@ private static void ProcessUpdate(ChatResponseUpdate update, ChatResponse respon
             response.ResponseId = update.ResponseId;
         }
 
-        if (update.ChatThreadId is not null)
+        if (update.ConversationId is not null)
         {
-            response.ChatThreadId = update.ChatThreadId;
+            response.ConversationId = update.ConversationId;
         }
 
         if (update.CreatedAt is not null)

src/Libraries/Microsoft.Extensions.AI.Abstractions/ChatCompletion/ChatResponseUpdate.cs

@@ -116,15 +116,16 @@ public IList<AIContent> Contents
     /// </remarks>
     public string? MessageId { get; set; }
 
-    /// <summary>Gets or sets the chat thread ID associated with the chat response of which this update is a part.</summary>
+    /// <summary>Gets or sets an identifier for the state of the conversation of which this update is a part.</summary>
     /// <remarks>
-    /// Some <see cref="IChatClient"/> implementations are capable of storing the state for a chat thread, such that
+    /// Some <see cref="IChatClient"/> implementations are capable of storing the state for a conversation, such that
     /// the input messages supplied to <see cref="IChatClient.GetStreamingResponseAsync"/> need only be the additional messages beyond
     /// what's already stored. If this property is non-<see langword="null"/>, it represents an identifier for that state,
-    /// and it should be used in a subsequent <see cref="ChatOptions.ChatThreadId"/> instead of supplying the same messages
-    /// (and this streaming message) as part of the <c>messages</c> parameter.
+    /// and it should be used in a subsequent <see cref="ChatOptions.ConversationId"/> instead of supplying the same messages
+    /// (and this streaming message) as part of the <c>messages</c> parameter. Note that the value may or may not differ on every
+    /// response, depending on whether the underlying provider uses a fixed ID for each conversation or updates it for each message.
     /// </remarks>
-    public string? ChatThreadId { get; set; }
+    public string? ConversationId { get; set; }
 
     /// <summary>Gets or sets a timestamp for the response update.</summary>
     public DateTimeOffset? CreatedAt { get; set; }

src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIResponseChatClient.cs

@@ -87,6 +87,7 @@ public async Task<ChatResponse> GetResponseAsync(
         ChatResponse response = new()
         {
             ResponseId = openAIResponse.Id,
+            ConversationId = openAIResponse.Id,
             CreatedAt = openAIResponse.CreatedAt,
             FinishReason = ToFinishReason(openAIResponse.IncompleteStatusDetails?.Reason),
             Messages = [new(ChatRole.Assistant, [])],
@@ -176,6 +177,7 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
                         Contents = ToUsageDetails(completedUpdate.Response) is { } usage ? [new UsageContent(usage)] : [],
                         CreatedAt = createdAt,
                         ResponseId = responseId,
+                        ConversationId = responseId,
                         FinishReason =
                             ToFinishReason(completedUpdate.Response?.IncompleteStatusDetails?.Reason) ??
                             (functionCallInfos is not null ? ChatFinishReason.ToolCalls : ChatFinishReason.Stop),
@@ -213,6 +215,7 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
                         MessageId = lastMessageId,
                         ModelId = modelId,
                         ResponseId = responseId,
+                        ConversationId = responseId,
                     };
                     break;
 
@@ -246,6 +249,7 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
                             MessageId = lastMessageId,
                             ModelId = modelId,
                             ResponseId = responseId,
+                            ConversationId = responseId,
                         };
                     }
 
@@ -259,6 +263,7 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
                         MessageId = lastMessageId,
                         ModelId = modelId,
                         ResponseId = responseId,
+                        ConversationId = responseId,
                         Contents =
                         [
                             new ErrorContent(errorUpdate.Message)
@@ -304,7 +309,7 @@ private static ResponseCreationOptions ToOpenAIResponseCreationOptions(ChatOptio
         {
             // Handle strongly-typed properties.
             result.MaxOutputTokenCount = options.MaxOutputTokens;
-            result.PreviousResponseId = options.ChatThreadId;
+            result.PreviousResponseId = options.ConversationId;
             result.TopP = options.TopP;
             result.Temperature = options.Temperature;
 

src/Libraries/Microsoft.Extensions.AI/ChatCompletion/CachingChatClient.cs

@@ -105,10 +105,10 @@ public override async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseA
             if (await ReadCacheStreamingAsync(cacheKey, cancellationToken) is { } existingChunks)
             {
                 // Yield all of the cached items.
-                string? chatThreadId = null;
+                string? conversationId = null;
                 foreach (var chunk in existingChunks)
                 {
-                    chatThreadId ??= chunk.ChatThreadId;
+                    conversationId ??= chunk.ConversationId;
                     yield return chunk;
                 }
             }

src/Libraries/Microsoft.Extensions.AI/ChatCompletion/ChatResponse{T}.cs

@@ -39,7 +39,7 @@ public ChatResponse(ChatResponse response, JsonSerializerOptions serializerOptio
     {
         _serializerOptions = Throw.IfNull(serializerOptions);
         AdditionalProperties = response.AdditionalProperties;
-        ChatThreadId = response.ChatThreadId;
+        ConversationId = response.ConversationId;
         CreatedAt = response.CreatedAt;
         FinishReason = response.FinishReason;
         ModelId = response.ModelId;

src/Libraries/Microsoft.Extensions.AI/ChatCompletion/FunctionInvokingChatClient.cs

@@ -224,7 +224,7 @@ public override async Task<ChatResponse> GetResponseAsync(
         List<ChatMessage>? responseMessages = null; // tracked list of messages, across multiple turns, to be used for the final response
         UsageDetails? totalUsage = null; // tracked usage across all turns, to be used for the final response
         List<FunctionCallContent>? functionCallContents = null; // function call contents that need responding to in the current turn
-        bool lastIterationHadThreadId = false; // whether the last iteration's response had a ChatThreadId set
+        bool lastIterationHadConversationId = false; // whether the last iteration's response had a ConversationId set
         int consecutiveErrorCount = 0;
 
         for (int iteration = 0; ; iteration++)
@@ -274,7 +274,7 @@ public override async Task<ChatResponse> GetResponseAsync(
             }
 
             // Prepare the history for the next iteration.
-            FixupHistories(originalMessages, ref messages, ref augmentedHistory, response, responseMessages, ref lastIterationHadThreadId);
+            FixupHistories(originalMessages, ref messages, ref augmentedHistory, response, responseMessages, ref lastIterationHadConversationId);
 
             // Add the responses from the function calls into the augmented history and also into the tracked
             // list of response messages.
@@ -287,7 +287,7 @@ public override async Task<ChatResponse> GetResponseAsync(
                 break;
             }
 
-            UpdateOptionsForNextIteration(ref options!, response.ChatThreadId);
+            UpdateOptionsForNextIteration(ref options!, response.ConversationId);
         }
 
         Debug.Assert(responseMessages is not null, "Expected to only be here if we have response messages.");
@@ -318,7 +318,7 @@ public override async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseA
         List<ChatMessage>? augmentedHistory = null; // the actual history of messages sent on turns other than the first
         List<FunctionCallContent>? functionCallContents = null; // function call contents that need responding to in the current turn
         List<ChatMessage>? responseMessages = null; // tracked list of messages, across multiple turns, to be used in fallback cases to reconstitute history
-        bool lastIterationHadThreadId = false; // whether the last iteration's response had a ChatThreadId set
+        bool lastIterationHadConversationId = false; // whether the last iteration's response had a ConversationId set
         List<ChatResponseUpdate> updates = []; // updates from the current response
         int consecutiveErrorCount = 0;
 
@@ -368,7 +368,7 @@ public override async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseA
             (responseMessages ??= []).AddRange(response.Messages);
 
             // Prepare the history for the next iteration.
-            FixupHistories(originalMessages, ref messages, ref augmentedHistory, response, responseMessages, ref lastIterationHadThreadId);
+            FixupHistories(originalMessages, ref messages, ref augmentedHistory, response, responseMessages, ref lastIterationHadConversationId);
 
             // Process all of the functions, adding their results into the history.
             var modeAndMessages = await ProcessFunctionCallsAsync(augmentedHistory, options, functionCallContents, iteration, consecutiveErrorCount, cancellationToken);
@@ -390,7 +390,7 @@ public override async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseA
                 {
                     AdditionalProperties = message.AdditionalProperties,
                     AuthorName = message.AuthorName,
-                    ChatThreadId = response.ChatThreadId,
+                    ConversationId = response.ConversationId,
                     CreatedAt = DateTimeOffset.UtcNow,
                     Contents = message.Contents,
                     RawRepresentation = message.RawRepresentation,
@@ -408,7 +408,7 @@ public override async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseA
                 break;
             }
 
-            UpdateOptionsForNextIteration(ref options, response.ChatThreadId);
+            UpdateOptionsForNextIteration(ref options, response.ConversationId);
         }
 
         AddUsageTags(activity, totalUsage);
@@ -437,18 +437,18 @@ private static void AddUsageTags(Activity? activity, UsageDetails? usage)
     /// <param name="augmentedHistory">The augmented history containing all the messages to be sent.</param>
     /// <param name="response">The most recent response being handled.</param>
     /// <param name="allTurnsResponseMessages">A list of all response messages received up until this point.</param>
-    /// <param name="lastIterationHadThreadId">Whether the previous iteration's response had a thread id.</param>
+    /// <param name="lastIterationHadConversationId">Whether the previous iteration's response had a conversation id.</param>
     private static void FixupHistories(
         IEnumerable<ChatMessage> originalMessages,
         ref IEnumerable<ChatMessage> messages,
         [NotNull] ref List<ChatMessage>? augmentedHistory,
         ChatResponse response,
         List<ChatMessage> allTurnsResponseMessages,
-        ref bool lastIterationHadThreadId)
+        ref bool lastIterationHadConversationId)
     {
         // We're now going to need to augment the history with function result contents.
         // That means we need a separate list to store the augmented history.
-        if (response.ChatThreadId is not null)
+        if (response.ConversationId is not null)
         {
             // The response indicates the inner client is tracking the history, so we don't want to send
             // anything we've already sent or received.
@@ -461,9 +461,9 @@ private static void FixupHistories(
                 augmentedHistory = [];
             }
 
-            lastIterationHadThreadId = true;
+            lastIterationHadConversationId = true;
         }
-        else if (lastIterationHadThreadId)
+        else if (lastIterationHadConversationId)
         {
             // In the very rare case where the inner client returned a response with a thread ID but then
             // returned a subsequent response without one, we want to reconstitue the full history. To do that,
@@ -474,7 +474,7 @@ private static void FixupHistories(
             augmentedHistory.AddRange(originalMessages);
             augmentedHistory.AddRange(allTurnsResponseMessages);
 
-            lastIterationHadThreadId = false;
+            lastIterationHadConversationId = false;
         }
         else
         {
@@ -486,7 +486,7 @@ private static void FixupHistories(
             // Now add the most recent response messages.
             augmentedHistory.AddMessages(response);
 
-            lastIterationHadThreadId = false;
+            lastIterationHadConversationId = false;
         }
 
         // Use the augmented history as the new set of messages to send.
@@ -525,22 +525,22 @@ private static bool CopyFunctionCalls(
         return any;
     }
 
-    private static void UpdateOptionsForNextIteration(ref ChatOptions options, string? chatThreadId)
+    private static void UpdateOptionsForNextIteration(ref ChatOptions options, string? conversationId)
     {
         if (options.ToolMode is RequiredChatToolMode)
         {
             // We have to reset the tool mode to be non-required after the first iteration,
             // as otherwise we'll be in an infinite loop.
             options = options.Clone();
             options.ToolMode = null;
-            options.ChatThreadId = chatThreadId;
+            options.ConversationId = conversationId;
         }
-        else if (options.ChatThreadId != chatThreadId)
+        else if (options.ConversationId != conversationId)
         {
             // As with the other modes, ensure we've propagated the chat thread ID to the options.
             // We only need to clone the options if we're actually mutating it.
             options = options.Clone();
-            options.ChatThreadId = chatThreadId;
+            options.ConversationId = conversationId;
         }
     }
 

test/Libraries/Microsoft.Extensions.AI.Abstractions.Tests/ChatCompletion/ChatOptionsTests.cs

@@ -13,7 +13,7 @@ public class ChatOptionsTests
     public void Constructor_Parameterless_PropsDefaulted()
     {
         ChatOptions options = new();
-        Assert.Null(options.ChatThreadId);
+        Assert.Null(options.ConversationId);
         Assert.Null(options.Temperature);
         Assert.Null(options.MaxOutputTokens);
         Assert.Null(options.TopP);
@@ -29,7 +29,7 @@ public void Constructor_Parameterless_PropsDefaulted()
         Assert.Null(options.AdditionalProperties);
 
         ChatOptions clone = options.Clone();
-        Assert.Null(options.ChatThreadId);
+        Assert.Null(options.ConversationId);
         Assert.Null(clone.Temperature);
         Assert.Null(clone.MaxOutputTokens);
         Assert.Null(clone.TopP);
@@ -67,7 +67,7 @@ public void Properties_Roundtrip()
             ["key"] = "value",
         };
 
-        options.ChatThreadId = "12345";
+        options.ConversationId = "12345";
         options.Temperature = 0.1f;
         options.MaxOutputTokens = 2;
         options.TopP = 0.3f;
@@ -82,7 +82,7 @@ public void Properties_Roundtrip()
         options.Tools = tools;
         options.AdditionalProperties = additionalProps;
 
-        Assert.Equal("12345", options.ChatThreadId);
+        Assert.Equal("12345", options.ConversationId);
         Assert.Equal(0.1f, options.Temperature);
         Assert.Equal(2, options.MaxOutputTokens);
         Assert.Equal(0.3f, options.TopP);
@@ -98,7 +98,7 @@ public void Properties_Roundtrip()
         Assert.Same(additionalProps, options.AdditionalProperties);
 
         ChatOptions clone = options.Clone();
-        Assert.Equal("12345", options.ChatThreadId);
+        Assert.Equal("12345", options.ConversationId);
         Assert.Equal(0.1f, clone.Temperature);
         Assert.Equal(2, clone.MaxOutputTokens);
         Assert.Equal(0.3f, clone.TopP);
@@ -130,7 +130,7 @@ public void JsonSerialization_Roundtrips()
             ["key"] = "value",
         };
 
-        options.ChatThreadId = "12345";
+        options.ConversationId = "12345";
         options.Temperature = 0.1f;
         options.MaxOutputTokens = 2;
         options.TopP = 0.3f;
@@ -154,7 +154,7 @@ public void JsonSerialization_Roundtrips()
         ChatOptions? deserialized = JsonSerializer.Deserialize(json, TestJsonSerializerContext.Default.ChatOptions);
         Assert.NotNull(deserialized);
 
-        Assert.Equal("12345", deserialized.ChatThreadId);
+        Assert.Equal("12345", deserialized.ConversationId);
         Assert.Equal(0.1f, deserialized.Temperature);
         Assert.Equal(2, deserialized.MaxOutputTokens);
         Assert.Equal(0.3f, deserialized.TopP);