.Net: Add responseMimeType Parameter to GeminiPromptExecutionSettings for Enhanced Output Control.

dotnet/src/Connectors/Connectors.Google.UnitTests/Core/Gemini/Clients/GeminiChatGenerationTests.cs

@@ -237,7 +237,8 @@ public async Task ShouldUsePromptExecutionSettingsAsync()
             MaxTokens = 102,
             Temperature = 0.45,
             TopP = 0.6,
-            AudioTimestamp = true
+            AudioTimestamp = true,
+            ResponseMimeType = "application/json"
         };
 
         // Act
@@ -249,6 +250,7 @@ public async Task ShouldUsePromptExecutionSettingsAsync()
         Assert.Equal(executionSettings.MaxTokens, geminiRequest.Configuration!.MaxOutputTokens);
         Assert.Equal(executionSettings.Temperature, geminiRequest.Configuration!.Temperature);
         Assert.Equal(executionSettings.AudioTimestamp, geminiRequest.Configuration!.AudioTimestamp);
+        Assert.Equal(executionSettings.ResponseMimeType, geminiRequest.Configuration!.ResponseMimeType);
         Assert.Equal(executionSettings.TopP, geminiRequest.Configuration!.TopP);
     }
 

dotnet/src/Connectors/Connectors.Google.UnitTests/Core/Gemini/GeminiRequestTests.cs

@@ -24,7 +24,8 @@ public void FromPromptItReturnsWithConfiguration()
             Temperature = 1.5,
             MaxTokens = 10,
             TopP = 0.9,
-            AudioTimestamp = true
+            AudioTimestamp = true,
+            ResponseMimeType = "application/json"
         };
 
         // Act
@@ -35,6 +36,7 @@ public void FromPromptItReturnsWithConfiguration()
         Assert.Equal(executionSettings.Temperature, request.Configuration.Temperature);
         Assert.Equal(executionSettings.MaxTokens, request.Configuration.MaxOutputTokens);
         Assert.Equal(executionSettings.AudioTimestamp, request.Configuration.AudioTimestamp);
+        Assert.Equal(executionSettings.ResponseMimeType, request.Configuration.ResponseMimeType);
         Assert.Equal(executionSettings.TopP, request.Configuration.TopP);
     }
 
@@ -87,7 +89,8 @@ public void FromChatHistoryItReturnsWithConfiguration()
             Temperature = 1.5,
             MaxTokens = 10,
             TopP = 0.9,
-            AudioTimestamp = true
+            AudioTimestamp = true,
+            ResponseMimeType = "application/json"
         };
 
         // Act
@@ -98,6 +101,7 @@ public void FromChatHistoryItReturnsWithConfiguration()
         Assert.Equal(executionSettings.Temperature, request.Configuration.Temperature);
         Assert.Equal(executionSettings.MaxTokens, request.Configuration.MaxOutputTokens);
         Assert.Equal(executionSettings.AudioTimestamp, request.Configuration.AudioTimestamp);
+        Assert.Equal(executionSettings.ResponseMimeType, request.Configuration.ResponseMimeType);
         Assert.Equal(executionSettings.TopP, request.Configuration.TopP);
     }
 

dotnet/src/Connectors/Connectors.Google.UnitTests/GeminiPromptExecutionSettingsTests.cs

@@ -27,6 +27,7 @@ public void ItCreatesGeminiExecutionSettingsWithCorrectDefaults()
         Assert.Null(executionSettings.CandidateCount);
         Assert.Null(executionSettings.SafetySettings);
         Assert.Null(executionSettings.AudioTimestamp);
+        Assert.Null(executionSettings.ResponseMimeType);
         Assert.Equal(GeminiPromptExecutionSettings.DefaultTextMaxTokens, executionSettings.MaxTokens);
     }
 
@@ -41,6 +42,7 @@ public void ItUsesExistingGeminiExecutionSettings()
             TopK = 20,
             CandidateCount = 3,
             AudioTimestamp = true,
+            ResponseMimeType = "application/json",
             StopSequences = ["foo", "bar"],
             MaxTokens = 128,
             SafetySettings =
@@ -67,7 +69,8 @@ public void ItCreatesGeminiExecutionSettingsFromExtensionDataSnakeCase()
             {
                 { "max_tokens", 1000 },
                 { "temperature", 0 },
-                { "audio_timestamp", true }
+                { "audio_timestamp", true },
+                { "response_mimetype", "application/json" }
             }
         };
 

dotnet/src/Connectors/Connectors.Google/Core/Gemini/Models/GeminiRequest.cs

@@ -248,7 +248,8 @@ private static void AddConfiguration(GeminiPromptExecutionSettings executionSett
             MaxOutputTokens = executionSettings.MaxTokens,
             StopSequences = executionSettings.StopSequences,
             CandidateCount = executionSettings.CandidateCount,
-            AudioTimestamp = executionSettings.AudioTimestamp
+            AudioTimestamp = executionSettings.AudioTimestamp,
+            ResponseMimeType = executionSettings.ResponseMimeType
         };
     }
 
@@ -287,5 +288,9 @@ internal sealed class ConfigurationElement
         [JsonPropertyName("audioTimestamp")]
         [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
         public bool? AudioTimestamp { get; set; }
+
+        [JsonPropertyName("responseMimeType")]
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+        public string? ResponseMimeType { get; set; }
     }
 }

dotnet/src/Connectors/Connectors.Google/GeminiPromptExecutionSettings.cs

@@ -24,6 +24,7 @@ public sealed class GeminiPromptExecutionSettings : PromptExecutionSettings
     private int? _candidateCount;
     private IList<string>? _stopSequences;
     private bool? _audioTimestamp;
+    private string? _responseMimeType;
     private IList<GeminiSafetySetting>? _safetySettings;
     private GeminiToolCallBehavior? _toolCallBehavior;
 
@@ -187,6 +188,24 @@ public bool? AudioTimestamp
         }
     }
 
+    /// <summary>
+    /// The output response MIME type of the generated candidate text.
+    /// The following MIME types are supported:
+    /// 1. application/json: JSON response in the candidates.
+    /// 2. text/plain (default): Plain text output.
+    /// 3. text/x.enum: For classification tasks, output an enum value as defined in the response schema.
+    /// </summary>
+    [JsonPropertyName("response_mimetype")]
+    public string? ResponseMimeType
+    {
+        get => this._responseMimeType;
+        set
+        {
+            this.ThrowIfFrozen();
+            this._responseMimeType = value;
+        }
+    }
+
     /// <inheritdoc />
     public override void Freeze()
     {
@@ -223,7 +242,8 @@ public override PromptExecutionSettings Clone()
             StopSequences = this.StopSequences is not null ? new List<string>(this.StopSequences) : null,
             SafetySettings = this.SafetySettings?.Select(setting => new GeminiSafetySetting(setting)).ToList(),
             ToolCallBehavior = this.ToolCallBehavior?.Clone(),
-            AudioTimestamp = this.AudioTimestamp
+            AudioTimestamp = this.AudioTimestamp,
+            ResponseMimeType = this.ResponseMimeType
         };
     }