fix(dotnet/connectors/openai): deduplicate top-level JSON keys when using ExtraBody

dotnet/src/Connectors/Connectors.OpenAI.UnitTests/Services/OpenAIChatCompletionExtraBodyTests.cs

@@ -1,7 +1,8 @@
-// Copyright (c) Microsoft. All rights reserved.
+// Copyright (c) Microsoft. All rights reserved.
 
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Net;
 using System.Net.Http;
 using System.Text;
@@ -206,6 +207,52 @@ public async Task ExtraBodyNullValueEmitsJsonNullAsync()
     }
 
     [Fact]
+    public async Task ExtraBodyToolsDoesNotEmitDuplicateToolsKeyInRequestBodyAsync()
+    {
+        // Arrange
+        var service = new OpenAIChatCompletionService("gpt-4o", apiKey: "NOKEY", httpClient: this._httpClient);
+        var settings = new OpenAIPromptExecutionSettings
+        {
+            ExtraBody = new Dictionary<string, object?>
+            {
+                ["tools"] = new[] { new { type = "web_search" } },
+            },
+        };
+
+        // Act
+        await service.GetChatMessageContentsAsync(this._chatHistory, settings);
+
+        // Assert
+        var jsonString = Encoding.UTF8.GetString(this._messageHandlerStub.RequestContent!);
+        int toolsKeyCount = System.Text.RegularExpressions.Regex.Matches(jsonString, "\"tools\"\\s*:").Count;
+        Assert.Equal(1, toolsKeyCount);
+    }
+
+    [Fact]
+    public async Task ExtraBodyDoesNotEmitDuplicateTopLevelKeysInRequestBodyAsync()
+    {
+        // Arrange
+        var service = new OpenAIChatCompletionService("gpt-4o", apiKey: "NOKEY", httpClient: this._httpClient);
+        var settings = new OpenAIPromptExecutionSettings
+        {
+            Temperature = 0.7,
+            ExtraBody = new Dictionary<string, object?>
+            {
+                ["temperature"] = 0.5,
+            },
+        };
+
+        // Act
+        await service.GetChatMessageContentsAsync(this._chatHistory, settings);
+
+        // Assert
+        var jsonString = Encoding.UTF8.GetString(this._messageHandlerStub.RequestContent!);
+        int tempKeyCount = System.Text.RegularExpressions.Regex.Matches(jsonString, "\"temperature\"\\s*:").Count;
+        Assert.Equal(1, tempKeyCount);
+    }
+
+    [Fact]
+
     public void FromExecutionSettingsRoundTripPreservesExtraBody()
     {
         // Arrange - deserializing through the base type (e.g. via PromptTemplateConfig) should preserve extra_body.

dotnet/src/Connectors/Connectors.OpenAI/Core/ClientCore.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft. All rights reserved.
+// Copyright (c) Microsoft. All rights reserved.
 
 using System;
 using System.ClientModel;
@@ -202,6 +202,7 @@ internal static OpenAIClientOptions GetOpenAIClientOptions(HttpClient? httpClien
         options.Endpoint ??= endpoint ?? httpClient?.BaseAddress;
 
         options.AddPolicy(CreateRequestHeaderPolicy(HttpHeaderConstant.Names.SemanticKernelVersion, HttpHeaderConstant.Values.GetAssemblyVersion(typeof(ClientCore))), PipelinePosition.PerCall);
+        options.AddPolicy(DeduplicateJsonKeysPipelinePolicy.Instance, PipelinePosition.PerCall);
 
         if (orgId is not null)
         {
@@ -270,4 +271,104 @@ protected static GenericActionPipelinePolicy CreateRequestHeaderPolicy(string he
             }
         });
     }
+
+    private sealed class DeduplicateJsonKeysPipelinePolicy : PipelinePolicy
+    {
+        public static DeduplicateJsonKeysPipelinePolicy Instance { get; } = new();
+
+        public override void Process(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex)
+        {
+            SanitizeMessageContent(message);
+            ProcessNext(message, pipeline, currentIndex);
+        }
+
+        public override async ValueTask ProcessAsync(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex)
+        {
+            SanitizeMessageContent(message);
+            await ProcessNextAsync(message, pipeline, currentIndex).ConfigureAwait(false);
+        }
+
+        private static void SanitizeMessageContent(PipelineMessage message)
+        {
+#pragma warning disable CA1031 // Do not let sanitization failures break request pipeline
+            try
+            {
+                if (message.Request.Content is null)
+                {
+                    return;
+                }
+
+                using var memoryStream = new System.IO.MemoryStream();
+                message.Request.Content.WriteTo(memoryStream, default);
+                byte[] bytes = memoryStream.ToArray();
+                if (bytes.Length == 0)
+                {
+                    return;
+                }
+
+                string rawJson = System.Text.Encoding.UTF8.GetString(bytes).TrimStart('\uFEFF', ' ', '\t', '\r', '\n');
+                if (!rawJson.StartsWith('{'))
+                {
+                    return;
+                }
+
+                string cleanJson = DeduplicateTopLevelJsonKeys(rawJson);
+                if (!string.Equals(rawJson, cleanJson, StringComparison.Ordinal))
+                {
+                    message.Request.Content = System.ClientModel.BinaryContent.Create(BinaryData.FromString(cleanJson));
+                }
+            }
+            catch
+            {
+                return;
+            }
+#pragma warning restore CA1031
+        }
+
+        private static string DeduplicateTopLevelJsonKeys(string rawJson)
+        {
+#pragma warning disable CA1031 // Catch all exceptions to prevent request pipeline failure
+            try
+            {
+                using var doc = System.Text.Json.JsonDocument.Parse(rawJson);
+                var root = doc.RootElement;
+                if (root.ValueKind != System.Text.Json.JsonValueKind.Object)
+                {
+                    return rawJson;
+                }
+
+                var dictionary = new Dictionary<string, System.Text.Json.JsonElement>(StringComparer.Ordinal);
+                bool hadDuplicates = false;
+                foreach (var prop in root.EnumerateObject())
+                {
+                    hadDuplicates |= dictionary.ContainsKey(prop.Name);
+                    dictionary[prop.Name] = prop.Value.Clone();
+                }
+
+                if (!hadDuplicates)
+                {
+                    return rawJson;
+                }
+
+                using var stream = new System.IO.MemoryStream();
+                using (var writer = new System.Text.Json.Utf8JsonWriter(stream))
+                {
+                    writer.WriteStartObject();
+                    foreach (var kvp in dictionary)
+                    {
+                        writer.WritePropertyName(kvp.Key);
+                        kvp.Value.WriteTo(writer);
+                    }
+                    writer.WriteEndObject();
+                }
+
+                return System.Text.Encoding.UTF8.GetString(stream.ToArray());
+            }
+            catch
+            {
+                return rawJson;
+            }
+#pragma warning restore CA1031
+        }
+    }
 }