diff --git a/src/libs/Google.Gemini/NextGen/Generated/Google.Gemini.NextGen.Models.PromptedVoice.g.cs b/src/libs/Google.Gemini/NextGen/Generated/Google.Gemini.NextGen.Models.PromptedVoice.g.cs
index 2b3e59970..4747508ef 100644
--- a/src/libs/Google.Gemini/NextGen/Generated/Google.Gemini.NextGen.Models.PromptedVoice.g.cs
+++ b/src/libs/Google.Gemini/NextGen/Generated/Google.Gemini.NextGen.Models.PromptedVoice.g.cs
@@ -10,6 +10,17 @@ namespace Google.Gemini.NextGen
     /// </summary>
     public sealed partial class PromptedVoice
     {
+        /// <summary>
+        /// Optional. The name or ID of an existing base voice to edit or remix.<br/>
+        /// Use the voice name for prebuilt voices (e.g., `Puck`) or the voice ID for<br/>
+        /// previously created voices (e.g., `voice_abc123`). This can be any<br/>
+        /// prompted or replicated voice that the user has access to.<br/>
+        /// When present, `input` describes relative alterations to make to the base<br/>
+        /// voice.
+        /// </summary>
+        [global::System.Text.Json.Serialization.JsonPropertyName("base_voice")]
+        public string? BaseVoice { get; set; }
+
         /// <summary>
         /// Required. The natural-language prompt describing the desired voice, e.g.<br/>
         /// "A deep, booming male voice of a massive evil ogre in his middle years."
@@ -31,12 +42,22 @@ public sealed partial class PromptedVoice
         /// Required. The natural-language prompt describing the desired voice, e.g.<br/>
         /// "A deep, booming male voice of a massive evil ogre in his middle years."
         /// </param>
+        /// <param name="baseVoice">
+        /// Optional. The name or ID of an existing base voice to edit or remix.<br/>
+        /// Use the voice name for prebuilt voices (e.g., `Puck`) or the voice ID for<br/>
+        /// previously created voices (e.g., `voice_abc123`). This can be any<br/>
+        /// prompted or replicated voice that the user has access to.<br/>
+        /// When present, `input` describes relative alterations to make to the base<br/>
+        /// voice.
+        /// </param>
 #if NET7_0_OR_GREATER
         [global::System.Diagnostics.CodeAnalysis.SetsRequiredMembers]
 #endif
         public PromptedVoice(
-            string input)
+            string input,
+            string? baseVoice)
         {
+            this.BaseVoice = baseVoice;
             this.Input = input ?? throw new global::System.ArgumentNullException(nameof(input));
         }
 
diff --git a/src/libs/Google.Gemini/nextgen.openapi.json b/src/libs/Google.Gemini/nextgen.openapi.json
index ec5f1da51..20686abc0 100644
--- a/src/libs/Google.Gemini/nextgen.openapi.json
+++ b/src/libs/Google.Gemini/nextgen.openapi.json
@@ -8528,6 +8528,10 @@
         "description": "Parameters for prompted voice generation.\nRequired in `CreateVoice` when `type` is `\"prompted\"`. Returned in\n`CreateVoice`, `GetVoice`, and `ListVoices` responses for prompted voices.",
         "type": "object",
         "properties": {
+          "base_voice": {
+            "description": "Optional. The name or ID of an existing base voice to edit or remix.\nUse the voice name for prebuilt voices (e.g., `Puck`) or the voice ID for\npreviously created voices (e.g., `voice_abc123`). This can be any\nprompted or replicated voice that the user has access to.\nWhen present, `input` describes relative alterations to make to the base\nvoice.",
+            "type": "string"
+          },
           "input": {
             "description": "Required. The natural-language prompt describing the desired voice, e.g.\n\"A deep, booming male voice of a massive evil ogre in his middle years.\"",
             "type": "string"