feat: Add voice activity detection signal.

PiperOrigin-RevId: 842366448

Author: MarkDaoust

Google.GenAI/LiveConverters.cs

@@ -619,6 +619,11 @@ internal JsonNode LiveClientSetupToMldev(JsonNode fromObject, JsonObject parentO
                               Common.GetValueByPath(fromObject, new string[] { "proactivity" }));
       }
 
+      if (!Common.IsZero(Common.GetValueByPath(fromObject, new string[] { "explicitVadSignal" }))) {
+        throw new NotSupportedException(
+            "explicitVadSignal parameter is not supported in Gemini API.");
+      }
+
       return toObject;
     }
 
@@ -691,6 +696,12 @@ internal JsonNode LiveClientSetupToVertex(JsonNode fromObject, JsonObject parent
                               Common.GetValueByPath(fromObject, new string[] { "proactivity" }));
       }
 
+      if (Common.GetValueByPath(fromObject, new string[] { "explicitVadSignal" }) != null) {
+        Common.SetValueByPath(
+            toObject, new string[] { "explicitVadSignal" },
+            Common.GetValueByPath(fromObject, new string[] { "explicitVadSignal" }));
+      }
+
       return toObject;
     }
 
@@ -819,6 +830,11 @@ internal JsonNode LiveConnectConfigToMldev(JsonNode fromObject, JsonObject paren
                               Common.GetValueByPath(fromObject, new string[] { "proactivity" }));
       }
 
+      if (!Common.IsZero(Common.GetValueByPath(fromObject, new string[] { "explicitVadSignal" }))) {
+        throw new NotSupportedException(
+            "explicitVadSignal parameter is not supported in Gemini API.");
+      }
+
       return toObject;
     }
 
@@ -946,6 +962,12 @@ internal JsonNode LiveConnectConfigToVertex(JsonNode fromObject, JsonObject pare
                               Common.GetValueByPath(fromObject, new string[] { "proactivity" }));
       }
 
+      if (Common.GetValueByPath(fromObject, new string[] { "explicitVadSignal" }) != null) {
+        Common.SetValueByPath(
+            parentObject, new string[] { "setup", "explicitVadSignal" },
+            Common.GetValueByPath(fromObject, new string[] { "explicitVadSignal" }));
+      }
+
       return toObject;
     }
 
@@ -1135,6 +1157,13 @@ internal JsonNode LiveServerMessageFromVertex(JsonNode fromObject, JsonObject pa
             Common.GetValueByPath(fromObject, new string[] { "sessionResumptionUpdate" }));
       }
 
+      if (Common.GetValueByPath(fromObject, new string[] { "voiceActivityDetectionSignal" }) !=
+          null) {
+        Common.SetValueByPath(
+            toObject, new string[] { "voiceActivityDetectionSignal" },
+            Common.GetValueByPath(fromObject, new string[] { "voiceActivityDetectionSignal" }));
+      }
+
       return toObject;
     }
 

Google.GenAI/types/LiveClientSetup.cs

@@ -131,6 +131,17 @@ public ProactivityConfig
             get; set;
           }
 
+    /// <summary>
+    /// Configures the explicit VAD signal. If enabled, the client will send vad_signal to indicate
+    /// the start and end of speech. This allows the server to process the audio more efficiently.
+    /// </summary>
+    [JsonPropertyName("explicitVadSignal")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+    public bool
+        ? ExplicitVadSignal {
+            get; set;
+          }
+
     /// <summary>
     /// Deserializes a JSON string to a LiveClientSetup object.
     /// </summary>

Google.GenAI/types/LiveConnectConfig.cs

@@ -241,6 +241,17 @@ public ProactivityConfig
             get; set;
           }
 
+    /// <summary>
+    /// Configures the explicit VAD signal. If enabled, the client will send vad_signal to indicate
+    /// the start and end of speech. This allows the server to process the audio more efficiently.
+    /// </summary>
+    [JsonPropertyName("explicitVadSignal")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+    public bool
+        ? ExplicitVadSignal {
+            get; set;
+          }
+
     /// <summary>
     /// Deserializes a JSON string to a LiveConnectConfig object.
     /// </summary>

Google.GenAI/types/LiveServerMessage.cs

@@ -96,6 +96,16 @@ public LiveServerSessionResumptionUpdate
             get; set;
           }
 
+    /// <summary>
+    /// Voice activity detection signal.
+    /// </summary>
+    [JsonPropertyName("voiceActivityDetectionSignal")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+    public VoiceActivityDetectionSignal
+        ? VoiceActivityDetectionSignal {
+            get; set;
+          }
+
     /// <summary>
     /// Deserializes a JSON string to a LiveServerMessage object.
     /// </summary>

Google.GenAI/types/VadSignalType.cs

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Auto-generated code. Do not edit.
+
+using System.Text.Json.Serialization;
+
+namespace Google.GenAI.Types {
+  /// <summary>
+  /// The type of the VAD signal.
+  /// </summary>
+  [JsonConverter(typeof(JsonStringEnumConverter))]
+  public enum VadSignalType {
+    /// <summary>
+    /// The default is VAD_SIGNAL_TYPE_UNSPECIFIED.
+    /// </summary>
+    [JsonPropertyName("VAD_SIGNAL_TYPE_UNSPECIFIED")] VAD_SIGNAL_TYPE_UNSPECIFIED,
+
+    /// <summary>
+    /// Start of sentence signal.
+    /// </summary>
+    [JsonPropertyName("VAD_SIGNAL_TYPE_SOS")] VAD_SIGNAL_TYPE_SOS,
+
+    /// <summary>
+    /// End of sentence signal.
+    /// </summary>
+    [JsonPropertyName("VAD_SIGNAL_TYPE_EOS")] VAD_SIGNAL_TYPE_EOS
+  }
+}

Google.GenAI/types/VoiceActivityDetectionSignal.cs

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Auto-generated code. Do not edit.
+
+using System;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Google.GenAI.Serialization;
+
+namespace Google.GenAI.Types {
+
+  public record VoiceActivityDetectionSignal {
+    /// <summary>
+    /// The type of the VAD signal.
+    /// </summary>
+    [JsonPropertyName("vadSignalType")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+    public VadSignalType ? VadSignalType { get; set; }
+
+    /// <summary>
+    /// Deserializes a JSON string to a VoiceActivityDetectionSignal object.
+    /// </summary>
+    /// <param name="jsonString">The JSON string to deserialize.</param>
+    /// <param name="options">Optional JsonSerializerOptions.</param>
+    /// <returns>The deserialized VoiceActivityDetectionSignal object, or null if deserialization
+    /// fails.</returns>
+    public static VoiceActivityDetectionSignal
+        ? FromJson(string jsonString, JsonSerializerOptions? options = null) {
+      try {
+        return JsonSerializer.Deserialize<VoiceActivityDetectionSignal>(jsonString, options);
+      } catch (JsonException e) {
+        Console.Error.WriteLine($"Error deserializing JSON: {e.ToString()}");
+        return null;
+      }
+    }
+  }
+}