diff --git a/src/v3/translation_service_client.ts b/src/v3/translation_service_client.ts
index e2608cf4..a0e6ad72 100644
--- a/src/v3/translation_service_client.ts
+++ b/src/v3/translation_service_client.ts
@@ -366,7 +366,7 @@ export class TranslationServiceClient {
   // -- Service calls --
   // -------------------
   translateText(
-    request: protos.google.cloud.translation.v3.ITranslateTextRequest,
+    request?: protos.google.cloud.translation.v3.ITranslateTextRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -474,7 +474,7 @@ export class TranslationServiceClient {
    * const [response] = await client.translateText(request);
    */
   translateText(
-    request: protos.google.cloud.translation.v3.ITranslateTextRequest,
+    request?: protos.google.cloud.translation.v3.ITranslateTextRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -517,7 +517,7 @@ export class TranslationServiceClient {
     return this.innerApiCalls.translateText(request, options, callback);
   }
   detectLanguage(
-    request: protos.google.cloud.translation.v3.IDetectLanguageRequest,
+    request?: protos.google.cloud.translation.v3.IDetectLanguageRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -599,7 +599,7 @@ export class TranslationServiceClient {
    * const [response] = await client.detectLanguage(request);
    */
   detectLanguage(
-    request: protos.google.cloud.translation.v3.IDetectLanguageRequest,
+    request?: protos.google.cloud.translation.v3.IDetectLanguageRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -642,7 +642,7 @@ export class TranslationServiceClient {
     return this.innerApiCalls.detectLanguage(request, options, callback);
   }
   getSupportedLanguages(
-    request: protos.google.cloud.translation.v3.IGetSupportedLanguagesRequest,
+    request?: protos.google.cloud.translation.v3.IGetSupportedLanguagesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -724,7 +724,7 @@ export class TranslationServiceClient {
    * const [response] = await client.getSupportedLanguages(request);
    */
   getSupportedLanguages(
-    request: protos.google.cloud.translation.v3.IGetSupportedLanguagesRequest,
+    request?: protos.google.cloud.translation.v3.IGetSupportedLanguagesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -770,7 +770,7 @@ export class TranslationServiceClient {
     return this.innerApiCalls.getSupportedLanguages(request, options, callback);
   }
   getGlossary(
-    request: protos.google.cloud.translation.v3.IGetGlossaryRequest,
+    request?: protos.google.cloud.translation.v3.IGetGlossaryRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -815,7 +815,7 @@ export class TranslationServiceClient {
    * const [response] = await client.getGlossary(request);
    */
   getGlossary(
-    request: protos.google.cloud.translation.v3.IGetGlossaryRequest,
+    request?: protos.google.cloud.translation.v3.IGetGlossaryRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -857,7 +857,7 @@ export class TranslationServiceClient {
   }
 
   batchTranslateText(
-    request: protos.google.cloud.translation.v3.IBatchTranslateTextRequest,
+    request?: protos.google.cloud.translation.v3.IBatchTranslateTextRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -969,7 +969,7 @@ export class TranslationServiceClient {
    * const [response] = await operation.promise();
    */
   batchTranslateText(
-    request: protos.google.cloud.translation.v3.IBatchTranslateTextRequest,
+    request?: protos.google.cloud.translation.v3.IBatchTranslateTextRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1054,7 +1054,7 @@ export class TranslationServiceClient {
     >;
   }
   createGlossary(
-    request: protos.google.cloud.translation.v3.ICreateGlossaryRequest,
+    request?: protos.google.cloud.translation.v3.ICreateGlossaryRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1113,7 +1113,7 @@ export class TranslationServiceClient {
    * const [response] = await operation.promise();
    */
   createGlossary(
-    request: protos.google.cloud.translation.v3.ICreateGlossaryRequest,
+    request?: protos.google.cloud.translation.v3.ICreateGlossaryRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1198,7 +1198,7 @@ export class TranslationServiceClient {
     >;
   }
   deleteGlossary(
-    request: protos.google.cloud.translation.v3.IDeleteGlossaryRequest,
+    request?: protos.google.cloud.translation.v3.IDeleteGlossaryRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1256,7 +1256,7 @@ export class TranslationServiceClient {
    * const [response] = await operation.promise();
    */
   deleteGlossary(
-    request: protos.google.cloud.translation.v3.IDeleteGlossaryRequest,
+    request?: protos.google.cloud.translation.v3.IDeleteGlossaryRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1341,7 +1341,7 @@ export class TranslationServiceClient {
     >;
   }
   listGlossaries(
-    request: protos.google.cloud.translation.v3.IListGlossariesRequest,
+    request?: protos.google.cloud.translation.v3.IListGlossariesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1405,7 +1405,7 @@ export class TranslationServiceClient {
    *   for more details and examples.
    */
   listGlossaries(
-    request: protos.google.cloud.translation.v3.IListGlossariesRequest,
+    request?: protos.google.cloud.translation.v3.IListGlossariesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v3beta1/translation_service_client.ts b/src/v3beta1/translation_service_client.ts
index 1bd668fc..306547a1 100644
--- a/src/v3beta1/translation_service_client.ts
+++ b/src/v3beta1/translation_service_client.ts
@@ -384,7 +384,7 @@ export class TranslationServiceClient {
   // -- Service calls --
   // -------------------
   translateText(
-    request: protos.google.cloud.translation.v3beta1.ITranslateTextRequest,
+    request?: protos.google.cloud.translation.v3beta1.ITranslateTextRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -493,7 +493,7 @@ export class TranslationServiceClient {
    * const [response] = await client.translateText(request);
    */
   translateText(
-    request: protos.google.cloud.translation.v3beta1.ITranslateTextRequest,
+    request?: protos.google.cloud.translation.v3beta1.ITranslateTextRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -536,7 +536,7 @@ export class TranslationServiceClient {
     return this.innerApiCalls.translateText(request, options, callback);
   }
   detectLanguage(
-    request: protos.google.cloud.translation.v3beta1.IDetectLanguageRequest,
+    request?: protos.google.cloud.translation.v3beta1.IDetectLanguageRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -621,7 +621,7 @@ export class TranslationServiceClient {
    * const [response] = await client.detectLanguage(request);
    */
   detectLanguage(
-    request: protos.google.cloud.translation.v3beta1.IDetectLanguageRequest,
+    request?: protos.google.cloud.translation.v3beta1.IDetectLanguageRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -667,7 +667,7 @@ export class TranslationServiceClient {
     return this.innerApiCalls.detectLanguage(request, options, callback);
   }
   getSupportedLanguages(
-    request: protos.google.cloud.translation.v3beta1.IGetSupportedLanguagesRequest,
+    request?: protos.google.cloud.translation.v3beta1.IGetSupportedLanguagesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -749,7 +749,7 @@ export class TranslationServiceClient {
    * const [response] = await client.getSupportedLanguages(request);
    */
   getSupportedLanguages(
-    request: protos.google.cloud.translation.v3beta1.IGetSupportedLanguagesRequest,
+    request?: protos.google.cloud.translation.v3beta1.IGetSupportedLanguagesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -795,7 +795,7 @@ export class TranslationServiceClient {
     return this.innerApiCalls.getSupportedLanguages(request, options, callback);
   }
   translateDocument(
-    request: protos.google.cloud.translation.v3beta1.ITranslateDocumentRequest,
+    request?: protos.google.cloud.translation.v3beta1.ITranslateDocumentRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -904,7 +904,7 @@ export class TranslationServiceClient {
    * const [response] = await client.translateDocument(request);
    */
   translateDocument(
-    request: protos.google.cloud.translation.v3beta1.ITranslateDocumentRequest,
+    request?: protos.google.cloud.translation.v3beta1.ITranslateDocumentRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -950,7 +950,7 @@ export class TranslationServiceClient {
     return this.innerApiCalls.translateDocument(request, options, callback);
   }
   getGlossary(
-    request: protos.google.cloud.translation.v3beta1.IGetGlossaryRequest,
+    request?: protos.google.cloud.translation.v3beta1.IGetGlossaryRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -999,7 +999,7 @@ export class TranslationServiceClient {
    * const [response] = await client.getGlossary(request);
    */
   getGlossary(
-    request: protos.google.cloud.translation.v3beta1.IGetGlossaryRequest,
+    request?: protos.google.cloud.translation.v3beta1.IGetGlossaryRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1043,7 +1043,7 @@ export class TranslationServiceClient {
   }
 
   batchTranslateText(
-    request: protos.google.cloud.translation.v3beta1.IBatchTranslateTextRequest,
+    request?: protos.google.cloud.translation.v3beta1.IBatchTranslateTextRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1155,7 +1155,7 @@ export class TranslationServiceClient {
    * const [response] = await operation.promise();
    */
   batchTranslateText(
-    request: protos.google.cloud.translation.v3beta1.IBatchTranslateTextRequest,
+    request?: protos.google.cloud.translation.v3beta1.IBatchTranslateTextRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1240,7 +1240,7 @@ export class TranslationServiceClient {
     >;
   }
   batchTranslateDocument(
-    request: protos.google.cloud.translation.v3beta1.IBatchTranslateDocumentRequest,
+    request?: protos.google.cloud.translation.v3beta1.IBatchTranslateDocumentRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1345,7 +1345,7 @@ export class TranslationServiceClient {
    * const [response] = await operation.promise();
    */
   batchTranslateDocument(
-    request: protos.google.cloud.translation.v3beta1.IBatchTranslateDocumentRequest,
+    request?: protos.google.cloud.translation.v3beta1.IBatchTranslateDocumentRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1434,7 +1434,7 @@ export class TranslationServiceClient {
     >;
   }
   createGlossary(
-    request: protos.google.cloud.translation.v3beta1.ICreateGlossaryRequest,
+    request?: protos.google.cloud.translation.v3beta1.ICreateGlossaryRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1493,7 +1493,7 @@ export class TranslationServiceClient {
    * const [response] = await operation.promise();
    */
   createGlossary(
-    request: protos.google.cloud.translation.v3beta1.ICreateGlossaryRequest,
+    request?: protos.google.cloud.translation.v3beta1.ICreateGlossaryRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1578,7 +1578,7 @@ export class TranslationServiceClient {
     >;
   }
   deleteGlossary(
-    request: protos.google.cloud.translation.v3beta1.IDeleteGlossaryRequest,
+    request?: protos.google.cloud.translation.v3beta1.IDeleteGlossaryRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1636,7 +1636,7 @@ export class TranslationServiceClient {
    * const [response] = await operation.promise();
    */
   deleteGlossary(
-    request: protos.google.cloud.translation.v3beta1.IDeleteGlossaryRequest,
+    request?: protos.google.cloud.translation.v3beta1.IDeleteGlossaryRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1721,7 +1721,7 @@ export class TranslationServiceClient {
     >;
   }
   listGlossaries(
-    request: protos.google.cloud.translation.v3beta1.IListGlossariesRequest,
+    request?: protos.google.cloud.translation.v3beta1.IListGlossariesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1798,7 +1798,7 @@ export class TranslationServiceClient {
    *   for more details and examples.
    */
   listGlossaries(
-    request: protos.google.cloud.translation.v3beta1.IListGlossariesRequest,
+    request?: protos.google.cloud.translation.v3beta1.IListGlossariesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<