fix: support LiteLLM Responses streaming

MeetingAssistant/Summary/FunctionInvocationGuard.cs

@@ -0,0 +1,26 @@
+using System.Text.Json.Nodes;
+using Microsoft.Extensions.AI;
+
+namespace MeetingAssistant.Summary;
+
+internal static class FunctionInvocationGuard
+{
+    public static ValueTask<object?> InvokeAsync(
+        FunctionInvocationContext context,
+        CancellationToken cancellationToken)
+    {
+        if (context.CallContent.Exception is not null)
+        {
+            return ValueTask.FromResult<object?>(new JsonObject
+            {
+                ["error"] = new JsonObject
+                {
+                    ["code"] = "invalid_tool_arguments",
+                    ["message"] = "Tool arguments must be a valid JSON object."
+                }
+            });
+        }
+
+        return context.Function.InvokeAsync(context.Arguments, cancellationToken);
+    }
+}

MeetingAssistant/Summary/LiteLlmResponsesChatClient.cs

@@ -1,20 +1,28 @@
 using System.Net.Http.Headers;
+using System.ClientModel;
+using System.ClientModel.Primitives;
 using System.Text;
 using System.Text.Json;
 using System.Text.Json.Nodes;
 using Microsoft.Agents.AI.Compaction;
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.Logging;
+using OpenAI;
+using OpenAI.Responses;
 
 namespace MeetingAssistant.Summary;
 
 #pragma warning disable MAAI001
+#pragma warning disable OPENAI001
 public sealed class LiteLlmResponsesChatClient : IChatClient
 {
     private static readonly JsonSerializerOptions JsonOptions = new(JsonSerializerDefaults.Web);
 
     private readonly HttpClient httpClient;
+    private readonly ResponsesClient responsesClient;
+    private readonly AsyncLocal<string?> requestInitiator = new();
     private readonly string model;
+    private readonly bool useStreaming;
     private readonly bool enableThinking;
     private readonly string reasoningEffort;
     private readonly int reconnectionAttempts;
@@ -37,7 +45,8 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
         ILogger? logger = null,
         bool firstRequestIsUser = true,
         Action? retrying = null,
-        Action<string>? reasoningSummaryChanged = null)
+        Action<string>? reasoningSummaryChanged = null,
+        bool useStreaming = true)
         : this(
             new HttpClient { BaseAddress = NormalizeEndpoint(endpoint) },
             apiKey,
@@ -50,7 +59,8 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
             logger,
             firstRequestIsUser,
             retrying,
-            reasoningSummaryChanged)
+            reasoningSummaryChanged,
+            useStreaming)
     {
     }
 
@@ -66,11 +76,14 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
         ILogger? logger = null,
         bool firstRequestIsUser = true,
         Action? retrying = null,
-        Action<string>? reasoningSummaryChanged = null)
+        Action<string>? reasoningSummaryChanged = null,
+        bool useStreaming = true)
     {
         this.httpClient = httpClient;
         this.httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);
+        responsesClient = CreateResponsesClient(httpClient, apiKey, requestInitiator);
         this.model = model;
+        this.useStreaming = useStreaming;
         this.enableThinking = enableThinking;
         this.reasoningEffort = reasoningEffort;
         this.reconnectionAttempts = Math.Max(0, reconnectionAttempts);
@@ -87,20 +100,50 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
         httpClient.Dispose();
     }
 
+    internal static LiteLlmResponsesChatClient Create(
+        AgentOptions options,
+        string apiKey,
+        LiteLlmResponsesCompactionOptions? compactionOptions,
+        ILogger? logger,
+        bool firstRequestIsUser,
+        Action? retrying = null,
+        Action<string>? reasoningSummaryChanged = null)
+    {
+        return new LiteLlmResponsesChatClient(
+            new Uri(options.Endpoint),
+            apiKey,
+            options.Model,
+            options.EnableThinking,
+            options.ReasoningEffort switch
+            {
+                ReasoningEffortOption.None => "none",
+                ReasoningEffortOption.Low => "low",
+                ReasoningEffortOption.High => "high",
+                ReasoningEffortOption.ExtraHigh => "xhigh",
+                _ => "medium"
+            },
+            options.ReconnectionAttempts,
+            options.ReconnectionDelay,
+            compactionOptions,
+            logger,
+            firstRequestIsUser,
+            retrying,
+            reasoningSummaryChanged,
+            options.UseStreaming);
+    }
+
     public async Task<ChatResponse> GetResponseAsync(
         IEnumerable<ChatMessage> messages,
         ChatOptions? options = null,
         CancellationToken cancellationToken = default)
     {
         var payload = await CreateCompactedPayloadAsync(messages.ToList(), options, cancellationToken).ConfigureAwait(false);
-        var responseJson = await PostWithRetryAsync(payload, cancellationToken).ConfigureAwait(false);
-
-        var response = ParseResponseJson(responseJson, out var reasoningSummaries);
-        ReportVisibleReasoningSummaries(reasoningSummaries);
-        LogResponseDiagnostics(responseJson, response);
-        ThrowIfResponseHasNoContent(responseJson, response);
-        LogResponseUsage(response.Usage);
-        return response;
+        var result = await PostWithRetryAsync(payload, cancellationToken).ConfigureAwait(false);
+        ReportVisibleReasoningSummaries(result.ReasoningSummaries);
+        LogResponseDiagnostics(result.Response);
+        ThrowIfResponseHasNoContent(result.Response);
+        LogResponseUsage(result.Response.Usage);
+        return result.Response;
     }
 
     public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
@@ -127,79 +170,14 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
             : null;
     }
 
-    public static ChatResponse ParseResponseJson(string responseJson)
+    private static IReadOnlyList<string> ExtractVisibleReasoningSummaries(ChatResponse response)
     {
-        return ParseResponseJson(responseJson, out _);
-    }
-
-    private static ChatResponse ParseResponseJson(
-        string responseJson,
-        out IReadOnlyList<string> reasoningSummaries)
-    {
-        using var document = JsonDocument.Parse(responseJson);
-        var root = document.RootElement;
-        var contents = new List<AIContent>();
-        reasoningSummaries = ExtractVisibleReasoningSummaries(root);
-
-        if (root.TryGetProperty("output", out var output) && output.ValueKind == JsonValueKind.Array)
-        {
-            foreach (var item in output.EnumerateArray())
-            {
-                var type = GetString(item, "type");
-                if (type == "message")
-                {
-                    AddMessageContent(contents, item);
-                }
-                else if (type == "function_call")
-                {
-                    contents.Add(new FunctionCallContent(
-                        GetRequiredString(item, "call_id"),
-                        GetRequiredString(item, "name"),
-                        ParseArguments(GetString(item, "arguments"))));
-                }
-            }
-        }
-
-        var message = new ChatMessage
-        {
-            Role = ChatRole.Assistant,
-            Contents = contents
-        };
-
-        return new ChatResponse(message)
-        {
-            ResponseId = GetString(root, "id"),
-            ModelId = GetString(root, "model"),
-            CreatedAt = GetUnixTimestamp(root, "created_at"),
-            Usage = ParseUsage(root),
-            RawRepresentation = responseJson
-        };
-    }
-
-    internal static IReadOnlyList<string> ExtractVisibleReasoningSummaries(string responseJson)
-    {
-        using var document = JsonDocument.Parse(responseJson);
-        return ExtractVisibleReasoningSummaries(document.RootElement);
-    }
-
-    private static IReadOnlyList<string> ExtractVisibleReasoningSummaries(JsonElement root)
-    {
-        var summaries = new List<string>();
-
-        if (!root.TryGetProperty("output", out var output) || output.ValueKind != JsonValueKind.Array)
-        {
-            return summaries;
-        }
-
-        foreach (var item in output.EnumerateArray())
-        {
-            if (GetString(item, "type") == "reasoning")
-            {
-                AddVisibleReasoningSummaryText(summaries, item);
-            }
-        }
-
-        return summaries;
+        return response.Messages
+            .SelectMany(message => message.Contents)
+            .OfType<TextReasoningContent>()
+            .Select(content => content.Text)
+            .Where(text => !string.IsNullOrWhiteSpace(text))
+            .ToArray();
     }
 
     private void ReportVisibleReasoningSummaries(IReadOnlyList<string> summaries)
@@ -407,7 +385,9 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
         return payload;
     }
 
-    private async Task<string> PostWithRetryAsync(JsonObject payload, CancellationToken cancellationToken)
+    private async Task<ResponsesChatResult> PostWithRetryAsync(
+        JsonObject payload,
+        CancellationToken cancellationToken)
     {
         var payloadJson = payload.ToJsonString(JsonOptions);
         Exception? lastException = null;
@@ -418,26 +398,36 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
             {
                 var initiator = NextInitiator();
                 LogRequestDiagnostics(payload, initiator, attempt);
-                using var request = CreateJsonRequest(
-                    "responses",
-                    payloadJson,
-                    initiator);
-                using var response = await httpClient.SendAsync(request, cancellationToken).ConfigureAwait(false);
-                var responseJson = await response.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);
 
-                if (response.IsSuccessStatusCode)
+                var createOptions = ModelReaderWriter.Read<CreateResponseOptions>(
+                        BinaryData.FromString(payloadJson),
+                        ModelReaderWriterOptions.Json)
+                    ?? throw new InvalidOperationException("Unable to create OpenAI Responses request options.");
+                createOptions.StreamingEnabled = useStreaming;
+
+                var previousInitiator = requestInitiator.Value;
+                requestInitiator.Value = initiator;
+                try
                 {
-                    return responseJson;
+                    return useStreaming
+                        ? await GetStreamingResponseAsync(createOptions, cancellationToken).ConfigureAwait(false)
+                        : CreateNonStreamingResult((await responsesClient
+                                .CreateResponseAsync(createOptions, cancellationToken)
+                                .ConfigureAwait(false))
+                            .Value
+                            .AsChatResponse(createOptions));
                 }
-
-                var exception = new InvalidOperationException(
-                    $"LiteLLM Responses request failed with {(int)response.StatusCode} {response.ReasonPhrase}: {responseJson}");
-                if (!IsRetryableStatusCode((int)response.StatusCode) || attempt == reconnectionAttempts)
+                finally
                 {
-                    throw exception;
+                    requestInitiator.Value = previousInitiator;
                 }
-
-                lastException = exception;
+            }
+            catch (ClientResultException exception)
+                when (!IsRetryableStatusCode(exception.Status) || attempt == reconnectionAttempts)
+            {
+                throw new InvalidOperationException(
+                    $"LiteLLM Responses request failed with {exception.Status}: {exception.Message}",
+                    exception);
             }
             catch (Exception exception) when (IsRetryableException(exception) && attempt < reconnectionAttempts)
             {
@@ -451,6 +441,48 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
         throw lastException ?? new InvalidOperationException("LiteLLM Responses request failed.");
     }
 
+    private async Task<ResponsesChatResult> GetStreamingResponseAsync(
+        CreateResponseOptions createOptions,
+        CancellationToken cancellationToken)
+    {
+        var updates = new List<ChatResponseUpdate>();
+        var reasoningSummaries = new Dictionary<(string ItemId, int SummaryIndex), StringBuilder>();
+        await foreach (var update in responsesClient
+                           .CreateResponseStreamingAsync(createOptions, cancellationToken)
+                           .AsChatResponseUpdatesAsync(createOptions, cancellationToken)
+                           .ConfigureAwait(false))
+        {
+            updates.Add(update);
+            var reasoningUpdate = update.RawRepresentation
+                as StreamingResponseReasoningSummaryTextDeltaUpdate;
+            if (reasoningUpdate is null)
+            {
+                continue;
+            }
+
+            var key = (reasoningUpdate.ItemId, reasoningUpdate.SummaryIndex);
+            if (!reasoningSummaries.TryGetValue(key, out var summary))
+            {
+                summary = new StringBuilder();
+                reasoningSummaries[key] = summary;
+            }
+
+            summary.Append(reasoningUpdate.Delta);
+        }
+
+        return new ResponsesChatResult(
+            updates.ToChatResponse(),
+            reasoningSummaries.Values
+                .Select(summary => summary.ToString())
+                .Where(summary => !string.IsNullOrWhiteSpace(summary))
+                .ToArray());
+    }
+
+    private static ResponsesChatResult CreateNonStreamingResult(ChatResponse response)
+    {
+        return new ResponsesChatResult(response, ExtractVisibleReasoningSummaries(response));
+    }
+
     private HttpRequestMessage CreateJsonRequest(
         string requestUri,
         string payloadJson,
@@ -489,7 +521,9 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
 
     private static bool IsRetryableException(Exception exception)
     {
-        return exception is HttpRequestException or TaskCanceledException;
+        return exception is ClientResultException clientException
+                && IsRetryableStatusCode(clientException.Status)
+            || exception is HttpRequestException or TaskCanceledException;
     }
 
     private void LogContextWindow(int estimatedTokens, bool compacted, string source)
@@ -561,18 +595,18 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
             instructionsPreview);
     }
 
-    private void LogResponseDiagnostics(string responseJson, ChatResponse response)
+    private void LogResponseDiagnostics(ChatResponse response)
     {
         if (logger is null)
         {
             return;
         }
 
-        var outputTypes = GetOutputItemTypes(responseJson);
         var parsedTypes = response.Messages
             .SelectMany(message => message.Contents)
             .Select(content => content.GetType().Name)
             .ToArray();
+        var outputTypes = GetOutputItemTypes(response);
         var functionCalls = response.Messages
             .SelectMany(message => message.Contents)
             .OfType<FunctionCallContent>()
@@ -590,40 +624,29 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
         if (parsedTypes.Length == 0)
         {
             logger.LogWarning(
-                "LiteLLM Responses response contained no parseable message text or function calls. Raw response preview: {ResponsePreview}",
-                Truncate(responseJson, maxLength: 6000));
+                "LiteLLM Responses response contained no parseable message text or function calls.");
         }
     }
 
-    private static void ThrowIfResponseHasNoContent(string responseJson, ChatResponse response)
+    private static void ThrowIfResponseHasNoContent(ChatResponse response)
     {
         if (response.Messages.SelectMany(message => message.Contents).Any())
         {
             return;
         }
 
-        var outputTypes = GetOutputItemTypes(responseJson);
+        var outputTypes = GetOutputItemTypes(response);
         throw new InvalidOperationException(
             "LiteLLM Responses returned no parseable message text or function calls. " +
             $"ResponseId={response.ResponseId ?? "<none>"}, outputTypes=[{string.Join(", ", outputTypes)}].");
     }
 
-    private static string[] GetOutputItemTypes(string responseJson)
+    private static string[] GetOutputItemTypes(ChatResponse response)
     {
-        try
-        {
-            using var document = JsonDocument.Parse(responseJson);
-            return document.RootElement.TryGetProperty("output", out var output) && output.ValueKind == JsonValueKind.Array
-                ? output
-                    .EnumerateArray()
-                    .Select(item => GetString(item, "type") ?? item.ValueKind.ToString())
-                    .ToArray()
-                : [];
-        }
-        catch (JsonException)
-        {
-            return ["<invalid-json>"];
-        }
+        return response.Messages
+            .SelectMany(message => message.Contents)
+            .Select(content => content.RawRepresentation?.GetType().Name ?? content.GetType().Name)
+            .ToArray();
     }
 
     private static string Truncate(string value, int maxLength)
@@ -649,10 +672,19 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
 
         if (!string.IsNullOrWhiteSpace(text))
         {
+            var isAssistant = role == ChatRole.Assistant.Value;
             input.Add(new JsonObject
             {
-                ["role"] = role == ChatRole.Assistant.Value ? "assistant" : "user",
-                ["content"] = text
+                ["type"] = "message",
+                ["role"] = isAssistant ? "assistant" : "user",
+                ["content"] = new JsonArray
+                {
+                    new JsonObject
+                    {
+                        ["type"] = isAssistant ? "output_text" : "input_text",
+                        ["text"] = text
+                    }
+                }
             });
         }
 
@@ -665,7 +697,7 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
                     ["type"] = "function_call",
                     ["call_id"] = call.CallId,
                     ["name"] = call.Name,
-                    ["arguments"] = JsonSerializer.Serialize(call.Arguments, JsonOptions)
+                    ["arguments"] = SerializeFunctionArguments(call)
                 });
             }
             else if (content is FunctionResultContent result)
@@ -702,110 +734,15 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
         return result;
     }
 
-    private static void AddMessageContent(List<AIContent> contents, JsonElement item)
+    private static string SerializeFunctionArguments(FunctionCallContent call)
     {
-        if (!item.TryGetProperty("content", out var messageContent) || messageContent.ValueKind != JsonValueKind.Array)
+        if (call.RawRepresentation is FunctionCallResponseItem responseItem
+            && responseItem.FunctionArguments is not null)
         {
-            return;
+            return responseItem.FunctionArguments.ToString();
         }
 
-        foreach (var content in messageContent.EnumerateArray())
-        {
-            if (GetString(content, "type") == "output_text")
-            {
-                var text = GetString(content, "text");
-                if (!string.IsNullOrEmpty(text))
-                {
-                    contents.Add(new TextContent(text));
-                }
-            }
-        }
-    }
-
-    private static void AddVisibleReasoningSummaryText(List<string> summaries, JsonElement item)
-    {
-        AddVisibleReasoningSummaryText(summaries, item, "summary");
-        AddVisibleReasoningSummaryText(summaries, item, "content");
-    }
-
-    private static void AddVisibleReasoningSummaryText(
-        List<string> summaries,
-        JsonElement item,
-        string propertyName)
-    {
-        if (!item.TryGetProperty(propertyName, out var property))
-        {
-            return;
-        }
-
-        if (property.ValueKind == JsonValueKind.String)
-        {
-            AddNonEmpty(summaries, property.GetString());
-            return;
-        }
-
-        if (property.ValueKind != JsonValueKind.Array)
-        {
-            return;
-        }
-
-        foreach (var summaryItem in property.EnumerateArray())
-        {
-            if (summaryItem.ValueKind == JsonValueKind.String)
-            {
-                AddNonEmpty(summaries, summaryItem.GetString());
-            }
-            else if (summaryItem.ValueKind == JsonValueKind.Object)
-            {
-                if (propertyName == "content" && !IsSummaryContent(summaryItem))
-                {
-                    continue;
-                }
-
-                AddNonEmpty(summaries, GetString(summaryItem, "text"));
-            }
-        }
-    }
-
-    private static bool IsSummaryContent(JsonElement item)
-    {
-        var type = GetString(item, "type");
-        return !string.IsNullOrWhiteSpace(type)
-            && type.Contains("summary", StringComparison.OrdinalIgnoreCase);
-    }
-
-    private static void AddNonEmpty(List<string> values, string? value)
-    {
-        if (!string.IsNullOrWhiteSpace(value))
-        {
-            values.Add(value.Trim());
-        }
-    }
-
-    private static Dictionary<string, object?> ParseArguments(string? arguments)
-    {
-        if (string.IsNullOrWhiteSpace(arguments))
-        {
-            return [];
-        }
-
-        using var document = JsonDocument.Parse(arguments);
-        return document.RootElement.EnumerateObject()
-            .ToDictionary(property => property.Name, property => ConvertJsonValue(property.Value));
-    }
-
-    private static object? ConvertJsonValue(JsonElement element)
-    {
-        return element.ValueKind switch
-        {
-            JsonValueKind.String => element.GetString(),
-            JsonValueKind.Number when element.TryGetInt64(out var integer) => integer,
-            JsonValueKind.Number when element.TryGetDouble(out var number) => number,
-            JsonValueKind.True => true,
-            JsonValueKind.False => false,
-            JsonValueKind.Null => null,
-            _ => JsonSerializer.Deserialize<object>(element.GetRawText(), JsonOptions)
-        };
+        return JsonSerializer.Serialize(call.Arguments, JsonOptions);
     }
 
     private static string ResultToString(object? result)
@@ -818,57 +755,12 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
         };
     }
 
-    private static UsageDetails? ParseUsage(JsonElement root)
-    {
-        if (!root.TryGetProperty("usage", out var usage) || usage.ValueKind != JsonValueKind.Object)
-        {
-            return null;
-        }
-
-        var inputTokens = GetInt(usage, "input_tokens") ?? GetInt(usage, "prompt_tokens");
-        var outputTokens = GetInt(usage, "output_tokens") ?? GetInt(usage, "completion_tokens");
-        var totalTokens = GetInt(usage, "total_tokens");
-        return new UsageDetails
-        {
-            InputTokenCount = inputTokens,
-            OutputTokenCount = outputTokens,
-            TotalTokenCount = totalTokens
-        };
-    }
-
     private static int EstimateTokens(JsonObject payload)
     {
         var json = payload.ToJsonString(JsonOptions);
         return Math.Max(1, (int)Math.Ceiling(json.Length / 4.0));
     }
 
-    private static int? GetInt(JsonElement element, string propertyName)
-    {
-        return element.TryGetProperty(propertyName, out var property) && property.TryGetInt32(out var value)
-            ? value
-            : null;
-    }
-
-    private static string GetRequiredString(JsonElement element, string propertyName)
-    {
-        return GetString(element, propertyName)
-            ?? throw new InvalidOperationException($"LiteLLM response item did not include '{propertyName}'.");
-    }
-
-    private static string? GetString(JsonElement element, string propertyName)
-    {
-        return element.TryGetProperty(propertyName, out var property) && property.ValueKind == JsonValueKind.String
-            ? property.GetString()
-            : null;
-    }
-
-    private static DateTimeOffset? GetUnixTimestamp(JsonElement element, string propertyName)
-    {
-        return element.TryGetProperty(propertyName, out var property) && property.TryGetInt64(out var value)
-            ? DateTimeOffset.FromUnixTimeSeconds(value)
-            : null;
-    }
-
     private static Uri NormalizeEndpoint(Uri endpoint)
     {
         var value = endpoint.ToString().TrimEnd('/');
@@ -884,5 +776,60 @@ public sealed class LiteLlmResponsesChatClient : IChatClient
     {
         return value.TrimStart('/');
     }
+
+    private static ResponsesClient CreateResponsesClient(
+        HttpClient httpClient,
+        string apiKey,
+        AsyncLocal<string?> requestInitiator)
+    {
+        var options = new OpenAIClientOptions
+        {
+            Endpoint = httpClient.BaseAddress
+                ?? throw new InvalidOperationException("LiteLLM HTTP client requires a base address."),
+            Transport = new HttpClientPipelineTransport(httpClient),
+            RetryPolicy = new ClientRetryPolicy(0)
+        };
+        options.AddPolicy(
+            new InitiatorHeaderPolicy(requestInitiator),
+            PipelinePosition.PerCall);
+
+        return new ResponsesClient(
+            new ApiKeyCredential(apiKey),
+            options);
+    }
+
+    private sealed record ResponsesChatResult(
+        ChatResponse Response,
+        IReadOnlyList<string> ReasoningSummaries);
+
+    private sealed class InitiatorHeaderPolicy(AsyncLocal<string?> requestInitiator) : PipelinePolicy
+    {
+        public override void Process(
+            PipelineMessage message,
+            IReadOnlyList<PipelinePolicy> pipeline,
+            int currentIndex)
+        {
+            SetHeader(message);
+            ProcessNext(message, pipeline, currentIndex);
+        }
+
+        public override ValueTask ProcessAsync(
+            PipelineMessage message,
+            IReadOnlyList<PipelinePolicy> pipeline,
+            int currentIndex)
+        {
+            SetHeader(message);
+            return ProcessNextAsync(message, pipeline, currentIndex);
+        }
+
+        private void SetHeader(PipelineMessage message)
+        {
+            if (!string.IsNullOrWhiteSpace(requestInitiator.Value))
+            {
+                message.Request.Headers.Set("X-Initiator", requestInitiator.Value);
+            }
+        }
+    }
 }
+#pragma warning restore OPENAI001
 #pragma warning restore MAAI001

MeetingAssistant/Summary/OpenAiMeetingSummaryAgentPipeline.cs

@@ -63,32 +63,24 @@ public sealed class OpenAiMeetingSummaryAgentPipeline : IMeetingSummaryPipeline
             meetingWorkflowEngine);
         var tools = CreateTools(meetingTools);
         var instructions = await instructionBuilder.BuildAsync(artifacts, options, cancellationToken);
-        using var compactionSummaryClient = new LiteLlmResponsesChatClient(
-            new Uri(agentOptions.Endpoint),
+        using var compactionSummaryClient = LiteLlmResponsesChatClient.Create(
+            agentOptions,
             key,
-            agentOptions.Model,
-            agentOptions.EnableThinking,
-            ToReasoningEffortValue(agentOptions.ReasoningEffort),
-            agentOptions.ReconnectionAttempts,
-            agentOptions.ReconnectionDelay,
             compactionOptions: null,
             logger,
             firstRequestIsUser: false);
         var compactionOptions = CreateCompactionOptions(agentOptions, compactionSummaryClient);
-        using var chatClient = new LiteLlmResponsesChatClient(
-            new Uri(agentOptions.Endpoint),
+        using var chatClient = LiteLlmResponsesChatClient.Create(
+            agentOptions,
             key,
-            agentOptions.Model,
-            agentOptions.EnableThinking,
-            ToReasoningEffortValue(agentOptions.ReasoningEffort),
-            agentOptions.ReconnectionAttempts,
-            agentOptions.ReconnectionDelay,
             compactionOptions,
             logger,
             firstRequestIsUser: false);
         var agent = chatClient
             .AsBuilder()
-            .UseFunctionInvocation()
+            .UseFunctionInvocation(
+                loggerFactory,
+                client => client.FunctionInvoker = FunctionInvocationGuard.InvokeAsync)
             .Build()
             .AsAIAgent(
                 instructions,
@@ -312,18 +304,6 @@ public sealed class OpenAiMeetingSummaryAgentPipeline : IMeetingSummaryPipeline
         return new PipelineCompactionStrategy(strategies);
     }
 
-    private static string ToReasoningEffortValue(ReasoningEffortOption effort)
-    {
-        return effort switch
-        {
-            ReasoningEffortOption.None => "none",
-            ReasoningEffortOption.Low => "low",
-            ReasoningEffortOption.High => "high",
-            ReasoningEffortOption.ExtraHigh => "xhigh",
-            _ => "medium"
-        };
-    }
-
     private static ReasoningEffort ToReasoningEffort(ReasoningEffortOption effort)
     {
         return effort switch