diff --git a/clients/google-api-services-texttospeech/v1/2.0.0/README.md b/clients/google-api-services-texttospeech/v1/2.0.0/README.md
index 0cecfbfdf2e..b39684c1e4c 100644
--- a/clients/google-api-services-texttospeech/v1/2.0.0/README.md
+++ b/clients/google-api-services-texttospeech/v1/2.0.0/README.md
@@ -22,7 +22,7 @@ Add the following lines to your `pom.xml` file:
     <dependency>
       <groupId>com.google.apis</groupId>
       <artifactId>google-api-services-texttospeech</artifactId>
-      <version>v1-rev20251202-2.0.0</version>
+      <version>v1-rev20260123-2.0.0</version>
     </dependency>
   </dependencies>
 </project>
@@ -35,7 +35,7 @@ repositories {
   mavenCentral()
 }
 dependencies {
-  implementation 'com.google.apis:google-api-services-texttospeech:v1-rev20251202-2.0.0'
+  implementation 'com.google.apis:google-api-services-texttospeech:v1-rev20260123-2.0.0'
 }
 ```
 
diff --git a/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/Texttospeech.java b/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/Texttospeech.java
index afe5e776fce..38fd7e82c1b 100644
--- a/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/Texttospeech.java
+++ b/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/Texttospeech.java
@@ -103,7 +103,7 @@ public class Texttospeech extends com.google.api.client.googleapis.services.json
    *        {@code com.google.api.client.extensions.appengine.http.UrlFetchTransport}</li>
    *        <li>Android: {@code newCompatibleTransport} from
    *        {@code com.google.api.client.extensions.android.http.AndroidHttp}</li>
-   *        <li>Java: {@link com.google.api.client.googleapis.javanet.GoogleNetHttpTransport#newTrustedTransport()}
+   *        <li>Java: {@code com.google.api.client.http.javanet.NetHttpTransport}</li>
    *        </li>
    *        </ul>
    * @param jsonFactory JSON factory, which may be:
@@ -1307,8 +1307,7 @@ private static String chooseEndpoint(com.google.api.client.http.HttpTransport tr
      *        {@code com.google.api.client.extensions.appengine.http.UrlFetchTransport}</li>
      *        <li>Android: {@code newCompatibleTransport} from
      *        {@code com.google.api.client.extensions.android.http.AndroidHttp}</li>
-     *        <li>Java: {@link com.google.api.client.googleapis.javanet.GoogleNetHttpTransport#newTrustedTransport()}
-     *        </li>
+     *        <li>Java: {@code com.google.api.client.http.javanet.NetHttpTransport}</li>
      *        </ul>
      * @param jsonFactory JSON factory, which may be:
      *        <ul>
diff --git a/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/model/AdvancedVoiceOptions.java b/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/model/AdvancedVoiceOptions.java
index 197435e1981..effea8dbd8d 100644
--- a/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/model/AdvancedVoiceOptions.java
+++ b/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/model/AdvancedVoiceOptions.java
@@ -30,6 +30,14 @@
 @SuppressWarnings("javadoc")
 public final class AdvancedVoiceOptions extends com.google.api.client.json.GenericJson {
 
+  /**
+   * Optional. If true, textnorm will be applied to text input. This feature is enabled by default.
+   * Only applies for Gemini TTS.
+   * The value may be {@code null}.
+   */
+  @com.google.api.client.util.Key
+  private java.lang.Boolean enableTextnorm;
+
   /**
    * Only for Journey voices. If false, the synthesis is context aware and has a higher latency.
    * The value may be {@code null}.
@@ -46,6 +54,25 @@ public final class AdvancedVoiceOptions extends com.google.api.client.json.Gener
   @com.google.api.client.util.Key
   private java.lang.Boolean relaxSafetyFilters;
 
+  /**
+   * Optional. If true, textnorm will be applied to text input. This feature is enabled by default.
+   * Only applies for Gemini TTS.
+   * @return value or {@code null} for none
+   */
+  public java.lang.Boolean getEnableTextnorm() {
+    return enableTextnorm;
+  }
+
+  /**
+   * Optional. If true, textnorm will be applied to text input. This feature is enabled by default.
+   * Only applies for Gemini TTS.
+   * @param enableTextnorm enableTextnorm or {@code null} for none
+   */
+  public AdvancedVoiceOptions setEnableTextnorm(java.lang.Boolean enableTextnorm) {
+    this.enableTextnorm = enableTextnorm;
+    return this;
+  }
+
   /**
    * Only for Journey voices. If false, the synthesis is context aware and has a higher latency.
    * @return value or {@code null} for none
diff --git a/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/model/SynthesizeSpeechRequest.java b/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/model/SynthesizeSpeechRequest.java
index 7059b37417d..f97f578833b 100644
--- a/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/model/SynthesizeSpeechRequest.java
+++ b/clients/google-api-services-texttospeech/v1/2.0.0/com/google/api/services/texttospeech/v1/model/SynthesizeSpeechRequest.java
@@ -31,7 +31,7 @@
 public final class SynthesizeSpeechRequest extends com.google.api.client.json.GenericJson {
 
   /**
-   * Advanced voice options.
+   * Optional. Advanced voice options.
    * The value may be {@code null}.
    */
   @com.google.api.client.util.Key
@@ -59,7 +59,7 @@ public final class SynthesizeSpeechRequest extends com.google.api.client.json.Ge
   private VoiceSelectionParams voice;
 
   /**
-   * Advanced voice options.
+   * Optional. Advanced voice options.
    * @return value or {@code null} for none
    */
   public AdvancedVoiceOptions getAdvancedVoiceOptions() {
@@ -67,7 +67,7 @@ public AdvancedVoiceOptions getAdvancedVoiceOptions() {
   }
 
   /**
-   * Advanced voice options.
+   * Optional. Advanced voice options.
    * @param advancedVoiceOptions advancedVoiceOptions or {@code null} for none
    */
   public SynthesizeSpeechRequest setAdvancedVoiceOptions(AdvancedVoiceOptions advancedVoiceOptions) {
diff --git a/clients/google-api-services-texttospeech/v1/2.0.0/pom.xml b/clients/google-api-services-texttospeech/v1/2.0.0/pom.xml
index af1fa4451a8..743aee6057d 100644
--- a/clients/google-api-services-texttospeech/v1/2.0.0/pom.xml
+++ b/clients/google-api-services-texttospeech/v1/2.0.0/pom.xml
@@ -8,8 +8,8 @@
 
   <groupId>com.google.apis</groupId>
   <artifactId>google-api-services-texttospeech</artifactId>
-  <version>v1-rev20251202-2.0.0</version>
-  <name>Cloud Text-to-Speech API v1-rev20251202-2.0.0</name>
+  <version>v1-rev20260123-2.0.0</version>
+  <name>Cloud Text-to-Speech API v1-rev20260123-2.0.0</name>
   <packaging>jar</packaging>
 
   <inceptionYear>2011</inceptionYear>
diff --git a/clients/google-api-services-texttospeech/v1/README.md b/clients/google-api-services-texttospeech/v1/README.md
index 0cecfbfdf2e..b39684c1e4c 100644
--- a/clients/google-api-services-texttospeech/v1/README.md
+++ b/clients/google-api-services-texttospeech/v1/README.md
@@ -22,7 +22,7 @@ Add the following lines to your `pom.xml` file:
     <dependency>
       <groupId>com.google.apis</groupId>
       <artifactId>google-api-services-texttospeech</artifactId>
-      <version>v1-rev20251202-2.0.0</version>
+      <version>v1-rev20260123-2.0.0</version>
     </dependency>
   </dependencies>
 </project>
@@ -35,7 +35,7 @@ repositories {
   mavenCentral()
 }
 dependencies {
-  implementation 'com.google.apis:google-api-services-texttospeech:v1-rev20251202-2.0.0'
+  implementation 'com.google.apis:google-api-services-texttospeech:v1-rev20260123-2.0.0'
 }
 ```
 
diff --git a/clients/google-api-services-texttospeech/v1beta1/2.0.0/README.md b/clients/google-api-services-texttospeech/v1beta1/2.0.0/README.md
index ce01b24a461..322bf5a00f8 100644
--- a/clients/google-api-services-texttospeech/v1beta1/2.0.0/README.md
+++ b/clients/google-api-services-texttospeech/v1beta1/2.0.0/README.md
@@ -22,7 +22,7 @@ Add the following lines to your `pom.xml` file:
     <dependency>
       <groupId>com.google.apis</groupId>
       <artifactId>google-api-services-texttospeech</artifactId>
-      <version>v1beta1-rev20251202-2.0.0</version>
+      <version>v1beta1-rev20260123-2.0.0</version>
     </dependency>
   </dependencies>
 </project>
@@ -35,7 +35,7 @@ repositories {
   mavenCentral()
 }
 dependencies {
-  implementation 'com.google.apis:google-api-services-texttospeech:v1beta1-rev20251202-2.0.0'
+  implementation 'com.google.apis:google-api-services-texttospeech:v1beta1-rev20260123-2.0.0'
 }
 ```
 
diff --git a/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/Texttospeech.java b/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/Texttospeech.java
index 5c514d32a06..8551d45fc66 100644
--- a/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/Texttospeech.java
+++ b/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/Texttospeech.java
@@ -103,7 +103,7 @@ public class Texttospeech extends com.google.api.client.googleapis.services.json
    *        {@code com.google.api.client.extensions.appengine.http.UrlFetchTransport}</li>
    *        <li>Android: {@code newCompatibleTransport} from
    *        {@code com.google.api.client.extensions.android.http.AndroidHttp}</li>
-   *        <li>Java: {@link com.google.api.client.googleapis.javanet.GoogleNetHttpTransport#newTrustedTransport()}
+   *        <li>Java: {@code com.google.api.client.http.javanet.NetHttpTransport}</li>
    *        </li>
    *        </ul>
    * @param jsonFactory JSON factory, which may be:
@@ -1008,8 +1008,7 @@ private static String chooseEndpoint(com.google.api.client.http.HttpTransport tr
      *        {@code com.google.api.client.extensions.appengine.http.UrlFetchTransport}</li>
      *        <li>Android: {@code newCompatibleTransport} from
      *        {@code com.google.api.client.extensions.android.http.AndroidHttp}</li>
-     *        <li>Java: {@link com.google.api.client.googleapis.javanet.GoogleNetHttpTransport#newTrustedTransport()}
-     *        </li>
+     *        <li>Java: {@code com.google.api.client.http.javanet.NetHttpTransport}</li>
      *        </ul>
      * @param jsonFactory JSON factory, which may be:
      *        <ul>
diff --git a/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/model/AdvancedVoiceOptions.java b/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/model/AdvancedVoiceOptions.java
index 70a0068c0e3..71dc750e719 100644
--- a/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/model/AdvancedVoiceOptions.java
+++ b/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/model/AdvancedVoiceOptions.java
@@ -30,6 +30,14 @@
 @SuppressWarnings("javadoc")
 public final class AdvancedVoiceOptions extends com.google.api.client.json.GenericJson {
 
+  /**
+   * Optional. If true, textnorm will be applied to text input. This feature is enabled by default.
+   * Only applies for Gemini TTS.
+   * The value may be {@code null}.
+   */
+  @com.google.api.client.util.Key
+  private java.lang.Boolean enableTextnorm;
+
   /**
    * Only for Journey voices. If false, the synthesis is context aware and has a higher latency.
    * The value may be {@code null}.
@@ -46,6 +54,25 @@ public final class AdvancedVoiceOptions extends com.google.api.client.json.Gener
   @com.google.api.client.util.Key
   private java.lang.Boolean relaxSafetyFilters;
 
+  /**
+   * Optional. If true, textnorm will be applied to text input. This feature is enabled by default.
+   * Only applies for Gemini TTS.
+   * @return value or {@code null} for none
+   */
+  public java.lang.Boolean getEnableTextnorm() {
+    return enableTextnorm;
+  }
+
+  /**
+   * Optional. If true, textnorm will be applied to text input. This feature is enabled by default.
+   * Only applies for Gemini TTS.
+   * @param enableTextnorm enableTextnorm or {@code null} for none
+   */
+  public AdvancedVoiceOptions setEnableTextnorm(java.lang.Boolean enableTextnorm) {
+    this.enableTextnorm = enableTextnorm;
+    return this;
+  }
+
   /**
    * Only for Journey voices. If false, the synthesis is context aware and has a higher latency.
    * @return value or {@code null} for none
diff --git a/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/model/SynthesizeSpeechRequest.java b/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/model/SynthesizeSpeechRequest.java
index 9c4b7aff26b..2aed8c01b1f 100644
--- a/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/model/SynthesizeSpeechRequest.java
+++ b/clients/google-api-services-texttospeech/v1beta1/2.0.0/com/google/api/services/texttospeech/v1beta1/model/SynthesizeSpeechRequest.java
@@ -31,7 +31,7 @@
 public final class SynthesizeSpeechRequest extends com.google.api.client.json.GenericJson {
 
   /**
-   * Advanced voice options.
+   * Optional. Advanced voice options.
    * The value may be {@code null}.
    */
   @com.google.api.client.util.Key
@@ -66,7 +66,7 @@ public final class SynthesizeSpeechRequest extends com.google.api.client.json.Ge
   private VoiceSelectionParams voice;
 
   /**
-   * Advanced voice options.
+   * Optional. Advanced voice options.
    * @return value or {@code null} for none
    */
   public AdvancedVoiceOptions getAdvancedVoiceOptions() {
@@ -74,7 +74,7 @@ public AdvancedVoiceOptions getAdvancedVoiceOptions() {
   }
 
   /**
-   * Advanced voice options.
+   * Optional. Advanced voice options.
    * @param advancedVoiceOptions advancedVoiceOptions or {@code null} for none
    */
   public SynthesizeSpeechRequest setAdvancedVoiceOptions(AdvancedVoiceOptions advancedVoiceOptions) {
diff --git a/clients/google-api-services-texttospeech/v1beta1/2.0.0/pom.xml b/clients/google-api-services-texttospeech/v1beta1/2.0.0/pom.xml
index 9f633774660..1d39dca4e64 100644
--- a/clients/google-api-services-texttospeech/v1beta1/2.0.0/pom.xml
+++ b/clients/google-api-services-texttospeech/v1beta1/2.0.0/pom.xml
@@ -8,8 +8,8 @@
 
   <groupId>com.google.apis</groupId>
   <artifactId>google-api-services-texttospeech</artifactId>
-  <version>v1beta1-rev20251202-2.0.0</version>
-  <name>Cloud Text-to-Speech API v1beta1-rev20251202-2.0.0</name>
+  <version>v1beta1-rev20260123-2.0.0</version>
+  <name>Cloud Text-to-Speech API v1beta1-rev20260123-2.0.0</name>
   <packaging>jar</packaging>
 
   <inceptionYear>2011</inceptionYear>
diff --git a/clients/google-api-services-texttospeech/v1beta1/README.md b/clients/google-api-services-texttospeech/v1beta1/README.md
index ce01b24a461..322bf5a00f8 100644
--- a/clients/google-api-services-texttospeech/v1beta1/README.md
+++ b/clients/google-api-services-texttospeech/v1beta1/README.md
@@ -22,7 +22,7 @@ Add the following lines to your `pom.xml` file:
     <dependency>
       <groupId>com.google.apis</groupId>
       <artifactId>google-api-services-texttospeech</artifactId>
-      <version>v1beta1-rev20251202-2.0.0</version>
+      <version>v1beta1-rev20260123-2.0.0</version>
     </dependency>
   </dependencies>
 </project>
@@ -35,7 +35,7 @@ repositories {
   mavenCentral()
 }
 dependencies {
-  implementation 'com.google.apis:google-api-services-texttospeech:v1beta1-rev20251202-2.0.0'
+  implementation 'com.google.apis:google-api-services-texttospeech:v1beta1-rev20260123-2.0.0'
 }
 ```