diff --git a/src/v1/dataset_service_client.ts b/src/v1/dataset_service_client.ts
index bfaec5e2..df358eb8 100644
--- a/src/v1/dataset_service_client.ts
+++ b/src/v1/dataset_service_client.ts
@@ -427,7 +427,7 @@ export class DatasetServiceClient {
   // -- Service calls --
   // -------------------
   getDataset(
-    request: protos.google.cloud.aiplatform.v1.IGetDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetDatasetRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -473,7 +473,7 @@ export class DatasetServiceClient {
    * const [response] = await client.getDataset(request);
    */
   getDataset(
-    request: protos.google.cloud.aiplatform.v1.IGetDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetDatasetRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -514,7 +514,7 @@ export class DatasetServiceClient {
     return this.innerApiCalls.getDataset(request, options, callback);
   }
   updateDataset(
-    request: protos.google.cloud.aiplatform.v1.IUpdateDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUpdateDatasetRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -570,7 +570,7 @@ export class DatasetServiceClient {
    * const [response] = await client.updateDataset(request);
    */
   updateDataset(
-    request: protos.google.cloud.aiplatform.v1.IUpdateDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUpdateDatasetRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -613,7 +613,7 @@ export class DatasetServiceClient {
     return this.innerApiCalls.updateDataset(request, options, callback);
   }
   getAnnotationSpec(
-    request: protos.google.cloud.aiplatform.v1.IGetAnnotationSpecRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetAnnotationSpecRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -665,7 +665,7 @@ export class DatasetServiceClient {
    * const [response] = await client.getAnnotationSpec(request);
    */
   getAnnotationSpec(
-    request: protos.google.cloud.aiplatform.v1.IGetAnnotationSpecRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetAnnotationSpecRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -709,7 +709,7 @@ export class DatasetServiceClient {
   }
 
   createDataset(
-    request: protos.google.cloud.aiplatform.v1.ICreateDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateDatasetRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -768,7 +768,7 @@ export class DatasetServiceClient {
    * const [response] = await operation.promise();
    */
   createDataset(
-    request: protos.google.cloud.aiplatform.v1.ICreateDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateDatasetRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -853,7 +853,7 @@ export class DatasetServiceClient {
     >;
   }
   deleteDataset(
-    request: protos.google.cloud.aiplatform.v1.IDeleteDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteDatasetRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -911,7 +911,7 @@ export class DatasetServiceClient {
    * const [response] = await operation.promise();
    */
   deleteDataset(
-    request: protos.google.cloud.aiplatform.v1.IDeleteDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteDatasetRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -996,7 +996,7 @@ export class DatasetServiceClient {
     >;
   }
   importData(
-    request: protos.google.cloud.aiplatform.v1.IImportDataRequest,
+    request?: protos.google.cloud.aiplatform.v1.IImportDataRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1057,7 +1057,7 @@ export class DatasetServiceClient {
    * const [response] = await operation.promise();
    */
   importData(
-    request: protos.google.cloud.aiplatform.v1.IImportDataRequest,
+    request?: protos.google.cloud.aiplatform.v1.IImportDataRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1142,7 +1142,7 @@ export class DatasetServiceClient {
     >;
   }
   exportData(
-    request: protos.google.cloud.aiplatform.v1.IExportDataRequest,
+    request?: protos.google.cloud.aiplatform.v1.IExportDataRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1202,7 +1202,7 @@ export class DatasetServiceClient {
    * const [response] = await operation.promise();
    */
   exportData(
-    request: protos.google.cloud.aiplatform.v1.IExportDataRequest,
+    request?: protos.google.cloud.aiplatform.v1.IExportDataRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1287,7 +1287,7 @@ export class DatasetServiceClient {
     >;
   }
   listDatasets(
-    request: protos.google.cloud.aiplatform.v1.IListDatasetsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListDatasetsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1366,7 +1366,7 @@ export class DatasetServiceClient {
    *   for more details and examples.
    */
   listDatasets(
-    request: protos.google.cloud.aiplatform.v1.IListDatasetsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListDatasetsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -1550,7 +1550,7 @@ export class DatasetServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1.IDataset>;
   }
   listDataItems(
-    request: protos.google.cloud.aiplatform.v1.IListDataItemsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListDataItemsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1614,7 +1614,7 @@ export class DatasetServiceClient {
    *   for more details and examples.
    */
   listDataItems(
-    request: protos.google.cloud.aiplatform.v1.IListDataItemsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListDataItemsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -1768,7 +1768,7 @@ export class DatasetServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1.IDataItem>;
   }
   listAnnotations(
-    request: protos.google.cloud.aiplatform.v1.IListAnnotationsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListAnnotationsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1832,7 +1832,7 @@ export class DatasetServiceClient {
    *   for more details and examples.
    */
   listAnnotations(
-    request: protos.google.cloud.aiplatform.v1.IListAnnotationsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListAnnotationsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1/endpoint_service_client.ts b/src/v1/endpoint_service_client.ts
index 7a19c83a..550f43b2 100644
--- a/src/v1/endpoint_service_client.ts
+++ b/src/v1/endpoint_service_client.ts
@@ -414,7 +414,7 @@ export class EndpointServiceClient {
   // -- Service calls --
   // -------------------
   getEndpoint(
-    request: protos.google.cloud.aiplatform.v1.IGetEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -460,7 +460,7 @@ export class EndpointServiceClient {
    * const [response] = await client.getEndpoint(request);
    */
   getEndpoint(
-    request: protos.google.cloud.aiplatform.v1.IGetEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -501,7 +501,7 @@ export class EndpointServiceClient {
     return this.innerApiCalls.getEndpoint(request, options, callback);
   }
   updateEndpoint(
-    request: protos.google.cloud.aiplatform.v1.IUpdateEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUpdateEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -551,7 +551,7 @@ export class EndpointServiceClient {
    * const [response] = await client.updateEndpoint(request);
    */
   updateEndpoint(
-    request: protos.google.cloud.aiplatform.v1.IUpdateEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUpdateEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -595,7 +595,7 @@ export class EndpointServiceClient {
   }
 
   createEndpoint(
-    request: protos.google.cloud.aiplatform.v1.ICreateEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -654,7 +654,7 @@ export class EndpointServiceClient {
    * const [response] = await operation.promise();
    */
   createEndpoint(
-    request: protos.google.cloud.aiplatform.v1.ICreateEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -739,7 +739,7 @@ export class EndpointServiceClient {
     >;
   }
   deleteEndpoint(
-    request: protos.google.cloud.aiplatform.v1.IDeleteEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -797,7 +797,7 @@ export class EndpointServiceClient {
    * const [response] = await operation.promise();
    */
   deleteEndpoint(
-    request: protos.google.cloud.aiplatform.v1.IDeleteEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -882,7 +882,7 @@ export class EndpointServiceClient {
     >;
   }
   deployModel(
-    request: protos.google.cloud.aiplatform.v1.IDeployModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeployModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -957,7 +957,7 @@ export class EndpointServiceClient {
    * const [response] = await operation.promise();
    */
   deployModel(
-    request: protos.google.cloud.aiplatform.v1.IDeployModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeployModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1042,7 +1042,7 @@ export class EndpointServiceClient {
     >;
   }
   undeployModel(
-    request: protos.google.cloud.aiplatform.v1.IUndeployModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUndeployModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1111,7 +1111,7 @@ export class EndpointServiceClient {
    * const [response] = await operation.promise();
    */
   undeployModel(
-    request: protos.google.cloud.aiplatform.v1.IUndeployModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUndeployModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1196,7 +1196,7 @@ export class EndpointServiceClient {
     >;
   }
   listEndpoints(
-    request: protos.google.cloud.aiplatform.v1.IListEndpointsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListEndpointsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1282,7 +1282,7 @@ export class EndpointServiceClient {
    *   for more details and examples.
    */
   listEndpoints(
-    request: protos.google.cloud.aiplatform.v1.IListEndpointsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListEndpointsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1/job_service_client.ts b/src/v1/job_service_client.ts
index 94d4c6cf..3a80adaf 100644
--- a/src/v1/job_service_client.ts
+++ b/src/v1/job_service_client.ts
@@ -453,7 +453,7 @@ export class JobServiceClient {
   // -- Service calls --
   // -------------------
   createCustomJob(
-    request: protos.google.cloud.aiplatform.v1.ICreateCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateCustomJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -505,7 +505,7 @@ export class JobServiceClient {
    * const [response] = await client.createCustomJob(request);
    */
   createCustomJob(
-    request: protos.google.cloud.aiplatform.v1.ICreateCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateCustomJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -548,7 +548,7 @@ export class JobServiceClient {
     return this.innerApiCalls.createCustomJob(request, options, callback);
   }
   getCustomJob(
-    request: protos.google.cloud.aiplatform.v1.IGetCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetCustomJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -594,7 +594,7 @@ export class JobServiceClient {
    * const [response] = await client.getCustomJob(request);
    */
   getCustomJob(
-    request: protos.google.cloud.aiplatform.v1.IGetCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetCustomJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -635,7 +635,7 @@ export class JobServiceClient {
     return this.innerApiCalls.getCustomJob(request, options, callback);
   }
   cancelCustomJob(
-    request: protos.google.cloud.aiplatform.v1.ICancelCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICancelCustomJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -694,7 +694,7 @@ export class JobServiceClient {
    * const [response] = await client.cancelCustomJob(request);
    */
   cancelCustomJob(
-    request: protos.google.cloud.aiplatform.v1.ICancelCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICancelCustomJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -737,7 +737,7 @@ export class JobServiceClient {
     return this.innerApiCalls.cancelCustomJob(request, options, callback);
   }
   createDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1.ICreateDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateDataLabelingJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -791,7 +791,7 @@ export class JobServiceClient {
    * const [response] = await client.createDataLabelingJob(request);
    */
   createDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1.ICreateDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateDataLabelingJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -837,7 +837,7 @@ export class JobServiceClient {
     return this.innerApiCalls.createDataLabelingJob(request, options, callback);
   }
   getDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1.IGetDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetDataLabelingJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -887,7 +887,7 @@ export class JobServiceClient {
    * const [response] = await client.getDataLabelingJob(request);
    */
   getDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1.IGetDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetDataLabelingJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -930,7 +930,7 @@ export class JobServiceClient {
     return this.innerApiCalls.getDataLabelingJob(request, options, callback);
   }
   cancelDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1.ICancelDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICancelDataLabelingJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -983,7 +983,7 @@ export class JobServiceClient {
    * const [response] = await client.cancelDataLabelingJob(request);
    */
   cancelDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1.ICancelDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICancelDataLabelingJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1029,7 +1029,7 @@ export class JobServiceClient {
     return this.innerApiCalls.cancelDataLabelingJob(request, options, callback);
   }
   createHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1.ICreateHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateHyperparameterTuningJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1083,7 +1083,7 @@ export class JobServiceClient {
    * const [response] = await client.createHyperparameterTuningJob(request);
    */
   createHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1.ICreateHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateHyperparameterTuningJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1133,7 +1133,7 @@ export class JobServiceClient {
     );
   }
   getHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1.IGetHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetHyperparameterTuningJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1186,7 +1186,7 @@ export class JobServiceClient {
    * const [response] = await client.getHyperparameterTuningJob(request);
    */
   getHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1.IGetHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetHyperparameterTuningJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1236,7 +1236,7 @@ export class JobServiceClient {
     );
   }
   cancelHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1.ICancelHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICancelHyperparameterTuningJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1298,7 +1298,7 @@ export class JobServiceClient {
    * const [response] = await client.cancelHyperparameterTuningJob(request);
    */
   cancelHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1.ICancelHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICancelHyperparameterTuningJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1348,7 +1348,7 @@ export class JobServiceClient {
     );
   }
   createBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1.ICreateBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateBatchPredictionJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1403,7 +1403,7 @@ export class JobServiceClient {
    * const [response] = await client.createBatchPredictionJob(request);
    */
   createBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1.ICreateBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateBatchPredictionJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1453,7 +1453,7 @@ export class JobServiceClient {
     );
   }
   getBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1.IGetBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetBatchPredictionJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1506,7 +1506,7 @@ export class JobServiceClient {
    * const [response] = await client.getBatchPredictionJob(request);
    */
   getBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1.IGetBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetBatchPredictionJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1552,7 +1552,7 @@ export class JobServiceClient {
     return this.innerApiCalls.getBatchPredictionJob(request, options, callback);
   }
   cancelBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1.ICancelBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICancelBatchPredictionJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1614,7 +1614,7 @@ export class JobServiceClient {
    * const [response] = await client.cancelBatchPredictionJob(request);
    */
   cancelBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1.ICancelBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICancelBatchPredictionJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1665,7 +1665,7 @@ export class JobServiceClient {
   }
 
   deleteCustomJob(
-    request: protos.google.cloud.aiplatform.v1.IDeleteCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteCustomJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1723,7 +1723,7 @@ export class JobServiceClient {
    * const [response] = await operation.promise();
    */
   deleteCustomJob(
-    request: protos.google.cloud.aiplatform.v1.IDeleteCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteCustomJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1808,7 +1808,7 @@ export class JobServiceClient {
     >;
   }
   deleteDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1.IDeleteDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteDataLabelingJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1866,7 +1866,7 @@ export class JobServiceClient {
    * const [response] = await operation.promise();
    */
   deleteDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1.IDeleteDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteDataLabelingJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1951,7 +1951,7 @@ export class JobServiceClient {
     >;
   }
   deleteHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1.IDeleteHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteHyperparameterTuningJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2009,7 +2009,7 @@ export class JobServiceClient {
    * const [response] = await operation.promise();
    */
   deleteHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1.IDeleteHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteHyperparameterTuningJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2098,7 +2098,7 @@ export class JobServiceClient {
     >;
   }
   deleteBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1.IDeleteBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteBatchPredictionJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2157,7 +2157,7 @@ export class JobServiceClient {
    * const [response] = await operation.promise();
    */
   deleteBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1.IDeleteBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteBatchPredictionJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2246,7 +2246,7 @@ export class JobServiceClient {
     >;
   }
   listCustomJobs(
-    request: protos.google.cloud.aiplatform.v1.IListCustomJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListCustomJobsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2325,7 +2325,7 @@ export class JobServiceClient {
    *   for more details and examples.
    */
   listCustomJobs(
-    request: protos.google.cloud.aiplatform.v1.IListCustomJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListCustomJobsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -2509,7 +2509,7 @@ export class JobServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1.ICustomJob>;
   }
   listDataLabelingJobs(
-    request: protos.google.cloud.aiplatform.v1.IListDataLabelingJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListDataLabelingJobsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2592,7 +2592,7 @@ export class JobServiceClient {
    *   for more details and examples.
    */
   listDataLabelingJobs(
-    request: protos.google.cloud.aiplatform.v1.IListDataLabelingJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListDataLabelingJobsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -2784,7 +2784,7 @@ export class JobServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1.IDataLabelingJob>;
   }
   listHyperparameterTuningJobs(
-    request: protos.google.cloud.aiplatform.v1.IListHyperparameterTuningJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListHyperparameterTuningJobsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2863,7 +2863,7 @@ export class JobServiceClient {
    *   for more details and examples.
    */
   listHyperparameterTuningJobs(
-    request: protos.google.cloud.aiplatform.v1.IListHyperparameterTuningJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListHyperparameterTuningJobsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3051,7 +3051,7 @@ export class JobServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1.IHyperparameterTuningJob>;
   }
   listBatchPredictionJobs(
-    request: protos.google.cloud.aiplatform.v1.IListBatchPredictionJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListBatchPredictionJobsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3132,7 +3132,7 @@ export class JobServiceClient {
    *   for more details and examples.
    */
   listBatchPredictionJobs(
-    request: protos.google.cloud.aiplatform.v1.IListBatchPredictionJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListBatchPredictionJobsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1/migration_service_client.ts b/src/v1/migration_service_client.ts
index 6579bce9..1cd4a231 100644
--- a/src/v1/migration_service_client.ts
+++ b/src/v1/migration_service_client.ts
@@ -381,7 +381,7 @@ export class MigrationServiceClient {
   // -------------------
 
   batchMigrateResources(
-    request: protos.google.cloud.aiplatform.v1.IBatchMigrateResourcesRequest,
+    request?: protos.google.cloud.aiplatform.v1.IBatchMigrateResourcesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -443,7 +443,7 @@ export class MigrationServiceClient {
    * const [response] = await operation.promise();
    */
   batchMigrateResources(
-    request: protos.google.cloud.aiplatform.v1.IBatchMigrateResourcesRequest,
+    request?: protos.google.cloud.aiplatform.v1.IBatchMigrateResourcesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -528,7 +528,7 @@ export class MigrationServiceClient {
     >;
   }
   searchMigratableResources(
-    request: protos.google.cloud.aiplatform.v1.ISearchMigratableResourcesRequest,
+    request?: protos.google.cloud.aiplatform.v1.ISearchMigratableResourcesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -603,7 +603,7 @@ export class MigrationServiceClient {
    *   for more details and examples.
    */
   searchMigratableResources(
-    request: protos.google.cloud.aiplatform.v1.ISearchMigratableResourcesRequest,
+    request?: protos.google.cloud.aiplatform.v1.ISearchMigratableResourcesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1/model_service_client.ts b/src/v1/model_service_client.ts
index 2f2c91bb..7141188b 100644
--- a/src/v1/model_service_client.ts
+++ b/src/v1/model_service_client.ts
@@ -417,7 +417,7 @@ export class ModelServiceClient {
   // -- Service calls --
   // -------------------
   getModel(
-    request: protos.google.cloud.aiplatform.v1.IGetModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -462,7 +462,7 @@ export class ModelServiceClient {
    * const [response] = await client.getModel(request);
    */
   getModel(
-    request: protos.google.cloud.aiplatform.v1.IGetModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -501,7 +501,7 @@ export class ModelServiceClient {
     return this.innerApiCalls.getModel(request, options, callback);
   }
   updateModel(
-    request: protos.google.cloud.aiplatform.v1.IUpdateModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUpdateModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -548,7 +548,7 @@ export class ModelServiceClient {
    * const [response] = await client.updateModel(request);
    */
   updateModel(
-    request: protos.google.cloud.aiplatform.v1.IUpdateModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUpdateModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -589,7 +589,7 @@ export class ModelServiceClient {
     return this.innerApiCalls.updateModel(request, options, callback);
   }
   getModelEvaluation(
-    request: protos.google.cloud.aiplatform.v1.IGetModelEvaluationRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetModelEvaluationRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -639,7 +639,7 @@ export class ModelServiceClient {
    * const [response] = await client.getModelEvaluation(request);
    */
   getModelEvaluation(
-    request: protos.google.cloud.aiplatform.v1.IGetModelEvaluationRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetModelEvaluationRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -682,7 +682,7 @@ export class ModelServiceClient {
     return this.innerApiCalls.getModelEvaluation(request, options, callback);
   }
   getModelEvaluationSlice(
-    request: protos.google.cloud.aiplatform.v1.IGetModelEvaluationSliceRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetModelEvaluationSliceRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -735,7 +735,7 @@ export class ModelServiceClient {
    * const [response] = await client.getModelEvaluationSlice(request);
    */
   getModelEvaluationSlice(
-    request: protos.google.cloud.aiplatform.v1.IGetModelEvaluationSliceRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetModelEvaluationSliceRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -786,7 +786,7 @@ export class ModelServiceClient {
   }
 
   uploadModel(
-    request: protos.google.cloud.aiplatform.v1.IUploadModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUploadModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -845,7 +845,7 @@ export class ModelServiceClient {
    * const [response] = await operation.promise();
    */
   uploadModel(
-    request: protos.google.cloud.aiplatform.v1.IUploadModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUploadModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -930,7 +930,7 @@ export class ModelServiceClient {
     >;
   }
   deleteModel(
-    request: protos.google.cloud.aiplatform.v1.IDeleteModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -989,7 +989,7 @@ export class ModelServiceClient {
    * const [response] = await operation.promise();
    */
   deleteModel(
-    request: protos.google.cloud.aiplatform.v1.IDeleteModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1074,7 +1074,7 @@ export class ModelServiceClient {
     >;
   }
   exportModel(
-    request: protos.google.cloud.aiplatform.v1.IExportModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IExportModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1135,7 +1135,7 @@ export class ModelServiceClient {
    * const [response] = await operation.promise();
    */
   exportModel(
-    request: protos.google.cloud.aiplatform.v1.IExportModelRequest,
+    request?: protos.google.cloud.aiplatform.v1.IExportModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1220,7 +1220,7 @@ export class ModelServiceClient {
     >;
   }
   listModels(
-    request: protos.google.cloud.aiplatform.v1.IListModelsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListModelsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1302,7 +1302,7 @@ export class ModelServiceClient {
    *   for more details and examples.
    */
   listModels(
-    request: protos.google.cloud.aiplatform.v1.IListModelsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListModelsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -1498,7 +1498,7 @@ export class ModelServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1.IModel>;
   }
   listModelEvaluations(
-    request: protos.google.cloud.aiplatform.v1.IListModelEvaluationsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListModelEvaluationsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1561,7 +1561,7 @@ export class ModelServiceClient {
    *   for more details and examples.
    */
   listModelEvaluations(
-    request: protos.google.cloud.aiplatform.v1.IListModelEvaluationsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListModelEvaluationsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -1713,7 +1713,7 @@ export class ModelServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1.IModelEvaluation>;
   }
   listModelEvaluationSlices(
-    request: protos.google.cloud.aiplatform.v1.IListModelEvaluationSlicesRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListModelEvaluationSlicesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1779,7 +1779,7 @@ export class ModelServiceClient {
    *   for more details and examples.
    */
   listModelEvaluationSlices(
-    request: protos.google.cloud.aiplatform.v1.IListModelEvaluationSlicesRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListModelEvaluationSlicesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1/pipeline_service_client.ts b/src/v1/pipeline_service_client.ts
index dca201f6..8934451b 100644
--- a/src/v1/pipeline_service_client.ts
+++ b/src/v1/pipeline_service_client.ts
@@ -386,7 +386,7 @@ export class PipelineServiceClient {
   // -- Service calls --
   // -------------------
   createTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1.ICreateTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateTrainingPipelineRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -441,7 +441,7 @@ export class PipelineServiceClient {
    * const [response] = await client.createTrainingPipeline(request);
    */
   createTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1.ICreateTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateTrainingPipelineRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -491,7 +491,7 @@ export class PipelineServiceClient {
     );
   }
   getTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1.IGetTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetTrainingPipelineRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -541,7 +541,7 @@ export class PipelineServiceClient {
    * const [response] = await client.getTrainingPipeline(request);
    */
   getTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1.IGetTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetTrainingPipelineRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -584,7 +584,7 @@ export class PipelineServiceClient {
     return this.innerApiCalls.getTrainingPipeline(request, options, callback);
   }
   cancelTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1.ICancelTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICancelTrainingPipelineRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -646,7 +646,7 @@ export class PipelineServiceClient {
    * const [response] = await client.cancelTrainingPipeline(request);
    */
   cancelTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1.ICancelTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICancelTrainingPipelineRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -697,7 +697,7 @@ export class PipelineServiceClient {
   }
 
   deleteTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1.IDeleteTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteTrainingPipelineRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -755,7 +755,7 @@ export class PipelineServiceClient {
    * const [response] = await operation.promise();
    */
   deleteTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1.IDeleteTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteTrainingPipelineRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -844,7 +844,7 @@ export class PipelineServiceClient {
     >;
   }
   listTrainingPipelines(
-    request: protos.google.cloud.aiplatform.v1.IListTrainingPipelinesRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListTrainingPipelinesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -922,7 +922,7 @@ export class PipelineServiceClient {
    *   for more details and examples.
    */
   listTrainingPipelines(
-    request: protos.google.cloud.aiplatform.v1.IListTrainingPipelinesRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListTrainingPipelinesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1/prediction_service_client.ts b/src/v1/prediction_service_client.ts
index dfa9eeb9..85160271 100644
--- a/src/v1/prediction_service_client.ts
+++ b/src/v1/prediction_service_client.ts
@@ -319,7 +319,7 @@ export class PredictionServiceClient {
   // -- Service calls --
   // -------------------
   predict(
-    request: protos.google.cloud.aiplatform.v1.IPredictRequest,
+    request?: protos.google.cloud.aiplatform.v1.IPredictRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -380,7 +380,7 @@ export class PredictionServiceClient {
    * const [response] = await client.predict(request);
    */
   predict(
-    request: protos.google.cloud.aiplatform.v1.IPredictRequest,
+    request?: protos.google.cloud.aiplatform.v1.IPredictRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
diff --git a/src/v1/specialist_pool_service_client.ts b/src/v1/specialist_pool_service_client.ts
index 16323dbc..407125ff 100644
--- a/src/v1/specialist_pool_service_client.ts
+++ b/src/v1/specialist_pool_service_client.ts
@@ -409,7 +409,7 @@ export class SpecialistPoolServiceClient {
   // -- Service calls --
   // -------------------
   getSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1.IGetSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetSpecialistPoolRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -459,7 +459,7 @@ export class SpecialistPoolServiceClient {
    * const [response] = await client.getSpecialistPool(request);
    */
   getSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1.IGetSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1.IGetSpecialistPoolRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -503,7 +503,7 @@ export class SpecialistPoolServiceClient {
   }
 
   createSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1.ICreateSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateSpecialistPoolRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -562,7 +562,7 @@ export class SpecialistPoolServiceClient {
    * const [response] = await operation.promise();
    */
   createSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1.ICreateSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1.ICreateSpecialistPoolRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -647,7 +647,7 @@ export class SpecialistPoolServiceClient {
     >;
   }
   deleteSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1.IDeleteSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteSpecialistPoolRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -708,7 +708,7 @@ export class SpecialistPoolServiceClient {
    * const [response] = await operation.promise();
    */
   deleteSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1.IDeleteSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1.IDeleteSpecialistPoolRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -793,7 +793,7 @@ export class SpecialistPoolServiceClient {
     >;
   }
   updateSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1.IUpdateSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUpdateSpecialistPoolRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -851,7 +851,7 @@ export class SpecialistPoolServiceClient {
    * const [response] = await operation.promise();
    */
   updateSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1.IUpdateSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1.IUpdateSpecialistPoolRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -936,7 +936,7 @@ export class SpecialistPoolServiceClient {
     >;
   }
   listSpecialistPools(
-    request: protos.google.cloud.aiplatform.v1.IListSpecialistPoolsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListSpecialistPoolsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -997,7 +997,7 @@ export class SpecialistPoolServiceClient {
    *   for more details and examples.
    */
   listSpecialistPools(
-    request: protos.google.cloud.aiplatform.v1.IListSpecialistPoolsRequest,
+    request?: protos.google.cloud.aiplatform.v1.IListSpecialistPoolsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/dataset_service_client.ts b/src/v1beta1/dataset_service_client.ts
index 431284d4..8e182c78 100644
--- a/src/v1beta1/dataset_service_client.ts
+++ b/src/v1beta1/dataset_service_client.ts
@@ -479,7 +479,7 @@ export class DatasetServiceClient {
   // -- Service calls --
   // -------------------
   getDataset(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetDatasetRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -529,7 +529,7 @@ export class DatasetServiceClient {
    * const [response] = await client.getDataset(request);
    */
   getDataset(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetDatasetRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -572,7 +572,7 @@ export class DatasetServiceClient {
     return this.innerApiCalls.getDataset(request, options, callback);
   }
   updateDataset(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateDatasetRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -628,7 +628,7 @@ export class DatasetServiceClient {
    * const [response] = await client.updateDataset(request);
    */
   updateDataset(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateDatasetRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -671,7 +671,7 @@ export class DatasetServiceClient {
     return this.innerApiCalls.updateDataset(request, options, callback);
   }
   getAnnotationSpec(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetAnnotationSpecRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetAnnotationSpecRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -726,7 +726,7 @@ export class DatasetServiceClient {
    * const [response] = await client.getAnnotationSpec(request);
    */
   getAnnotationSpec(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetAnnotationSpecRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetAnnotationSpecRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -773,7 +773,7 @@ export class DatasetServiceClient {
   }
 
   createDataset(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateDatasetRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -832,7 +832,7 @@ export class DatasetServiceClient {
    * const [response] = await operation.promise();
    */
   createDataset(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateDatasetRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -917,7 +917,7 @@ export class DatasetServiceClient {
     >;
   }
   deleteDataset(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteDatasetRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -975,7 +975,7 @@ export class DatasetServiceClient {
    * const [response] = await operation.promise();
    */
   deleteDataset(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteDatasetRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteDatasetRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1060,7 +1060,7 @@ export class DatasetServiceClient {
     >;
   }
   importData(
-    request: protos.google.cloud.aiplatform.v1beta1.IImportDataRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IImportDataRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1121,7 +1121,7 @@ export class DatasetServiceClient {
    * const [response] = await operation.promise();
    */
   importData(
-    request: protos.google.cloud.aiplatform.v1beta1.IImportDataRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IImportDataRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1206,7 +1206,7 @@ export class DatasetServiceClient {
     >;
   }
   exportData(
-    request: protos.google.cloud.aiplatform.v1beta1.IExportDataRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IExportDataRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1266,7 +1266,7 @@ export class DatasetServiceClient {
    * const [response] = await operation.promise();
    */
   exportData(
-    request: protos.google.cloud.aiplatform.v1beta1.IExportDataRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IExportDataRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1351,7 +1351,7 @@ export class DatasetServiceClient {
     >;
   }
   listDatasets(
-    request: protos.google.cloud.aiplatform.v1beta1.IListDatasetsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListDatasetsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1430,7 +1430,7 @@ export class DatasetServiceClient {
    *   for more details and examples.
    */
   listDatasets(
-    request: protos.google.cloud.aiplatform.v1beta1.IListDatasetsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListDatasetsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -1614,7 +1614,7 @@ export class DatasetServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IDataset>;
   }
   listDataItems(
-    request: protos.google.cloud.aiplatform.v1beta1.IListDataItemsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListDataItemsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1678,7 +1678,7 @@ export class DatasetServiceClient {
    *   for more details and examples.
    */
   listDataItems(
-    request: protos.google.cloud.aiplatform.v1beta1.IListDataItemsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListDataItemsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -1832,7 +1832,7 @@ export class DatasetServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IDataItem>;
   }
   listAnnotations(
-    request: protos.google.cloud.aiplatform.v1beta1.IListAnnotationsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListAnnotationsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1896,7 +1896,7 @@ export class DatasetServiceClient {
    *   for more details and examples.
    */
   listAnnotations(
-    request: protos.google.cloud.aiplatform.v1beta1.IListAnnotationsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListAnnotationsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/endpoint_service_client.ts b/src/v1beta1/endpoint_service_client.ts
index 4e533fc0..62c76872 100644
--- a/src/v1beta1/endpoint_service_client.ts
+++ b/src/v1beta1/endpoint_service_client.ts
@@ -466,7 +466,7 @@ export class EndpointServiceClient {
   // -- Service calls --
   // -------------------
   getEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -516,7 +516,7 @@ export class EndpointServiceClient {
    * const [response] = await client.getEndpoint(request);
    */
   getEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -559,7 +559,7 @@ export class EndpointServiceClient {
     return this.innerApiCalls.getEndpoint(request, options, callback);
   }
   updateEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -609,7 +609,7 @@ export class EndpointServiceClient {
    * const [response] = await client.updateEndpoint(request);
    */
   updateEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -653,7 +653,7 @@ export class EndpointServiceClient {
   }
 
   createEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -712,7 +712,7 @@ export class EndpointServiceClient {
    * const [response] = await operation.promise();
    */
   createEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -797,7 +797,7 @@ export class EndpointServiceClient {
     >;
   }
   deleteEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -855,7 +855,7 @@ export class EndpointServiceClient {
    * const [response] = await operation.promise();
    */
   deleteEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -940,7 +940,7 @@ export class EndpointServiceClient {
     >;
   }
   deployModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeployModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeployModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1015,7 +1015,7 @@ export class EndpointServiceClient {
    * const [response] = await operation.promise();
    */
   deployModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeployModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeployModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1100,7 +1100,7 @@ export class EndpointServiceClient {
     >;
   }
   undeployModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IUndeployModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUndeployModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1169,7 +1169,7 @@ export class EndpointServiceClient {
    * const [response] = await operation.promise();
    */
   undeployModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IUndeployModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUndeployModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1254,7 +1254,7 @@ export class EndpointServiceClient {
     >;
   }
   listEndpoints(
-    request: protos.google.cloud.aiplatform.v1beta1.IListEndpointsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListEndpointsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1331,7 +1331,7 @@ export class EndpointServiceClient {
    *   for more details and examples.
    */
   listEndpoints(
-    request: protos.google.cloud.aiplatform.v1beta1.IListEndpointsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListEndpointsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/featurestore_online_serving_service_client.ts b/src/v1beta1/featurestore_online_serving_service_client.ts
index 3b6c2f0c..4eec36ac 100644
--- a/src/v1beta1/featurestore_online_serving_service_client.ts
+++ b/src/v1beta1/featurestore_online_serving_service_client.ts
@@ -384,7 +384,7 @@ export class FeaturestoreOnlineServingServiceClient {
   // -- Service calls --
   // -------------------
   readFeatureValues(
-    request: protos.google.cloud.aiplatform.v1beta1.IReadFeatureValuesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IReadFeatureValuesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -447,7 +447,7 @@ export class FeaturestoreOnlineServingServiceClient {
    * const [response] = await client.readFeatureValues(request);
    */
   readFeatureValues(
-    request: protos.google.cloud.aiplatform.v1beta1.IReadFeatureValuesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IReadFeatureValuesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
diff --git a/src/v1beta1/featurestore_service_client.ts b/src/v1beta1/featurestore_service_client.ts
index 65e37652..c9ffe5e0 100644
--- a/src/v1beta1/featurestore_service_client.ts
+++ b/src/v1beta1/featurestore_service_client.ts
@@ -580,7 +580,7 @@ export class FeaturestoreServiceClient {
   // -- Service calls --
   // -------------------
   getFeaturestore(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetFeaturestoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetFeaturestoreRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -631,7 +631,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await client.getFeaturestore(request);
    */
   getFeaturestore(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetFeaturestoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetFeaturestoreRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -677,7 +677,7 @@ export class FeaturestoreServiceClient {
     return this.innerApiCalls.getFeaturestore(request, options, callback);
   }
   getEntityType(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetEntityTypeRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetEntityTypeRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -727,7 +727,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await client.getEntityType(request);
    */
   getEntityType(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetEntityTypeRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetEntityTypeRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -770,7 +770,7 @@ export class FeaturestoreServiceClient {
     return this.innerApiCalls.getEntityType(request, options, callback);
   }
   updateEntityType(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateEntityTypeRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateEntityTypeRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -839,7 +839,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await client.updateEntityType(request);
    */
   updateEntityType(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateEntityTypeRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateEntityTypeRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -885,7 +885,7 @@ export class FeaturestoreServiceClient {
     return this.innerApiCalls.updateEntityType(request, options, callback);
   }
   getFeature(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetFeatureRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetFeatureRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -935,7 +935,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await client.getFeature(request);
    */
   getFeature(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetFeatureRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetFeatureRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -978,7 +978,7 @@ export class FeaturestoreServiceClient {
     return this.innerApiCalls.getFeature(request, options, callback);
   }
   updateFeature(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateFeatureRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateFeatureRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1044,7 +1044,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await client.updateFeature(request);
    */
   updateFeature(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateFeatureRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateFeatureRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1088,7 +1088,7 @@ export class FeaturestoreServiceClient {
   }
 
   createFeaturestore(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateFeaturestoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateFeaturestoreRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1156,7 +1156,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   createFeaturestore(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateFeaturestoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateFeaturestoreRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1241,7 +1241,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   updateFeaturestore(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateFeaturestoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateFeaturestoreRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1313,7 +1313,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   updateFeaturestore(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateFeaturestoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateFeaturestoreRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1398,7 +1398,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   deleteFeaturestore(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteFeaturestoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteFeaturestoreRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1461,7 +1461,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   deleteFeaturestore(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteFeaturestoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteFeaturestoreRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1546,7 +1546,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   createEntityType(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateEntityTypeRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateEntityTypeRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1614,7 +1614,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   createEntityType(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateEntityTypeRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateEntityTypeRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1699,7 +1699,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   deleteEntityType(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteEntityTypeRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteEntityTypeRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1761,7 +1761,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   deleteEntityType(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteEntityTypeRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteEntityTypeRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1846,7 +1846,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   createFeature(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateFeatureRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateFeatureRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1914,7 +1914,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   createFeature(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateFeatureRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateFeatureRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1999,7 +1999,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   batchCreateFeatures(
-    request: protos.google.cloud.aiplatform.v1beta1.IBatchCreateFeaturesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IBatchCreateFeaturesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2062,7 +2062,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   batchCreateFeatures(
-    request: protos.google.cloud.aiplatform.v1beta1.IBatchCreateFeaturesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IBatchCreateFeaturesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2147,7 +2147,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   deleteFeature(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteFeatureRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteFeatureRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2205,7 +2205,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   deleteFeature(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteFeatureRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteFeatureRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2290,7 +2290,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   importFeatureValues(
-    request: protos.google.cloud.aiplatform.v1beta1.IImportFeatureValuesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IImportFeatureValuesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2394,7 +2394,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   importFeatureValues(
-    request: protos.google.cloud.aiplatform.v1beta1.IImportFeatureValuesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IImportFeatureValuesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2479,7 +2479,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   batchReadFeatureValues(
-    request: protos.google.cloud.aiplatform.v1beta1.IBatchReadFeatureValuesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IBatchReadFeatureValuesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2575,7 +2575,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   batchReadFeatureValues(
-    request: protos.google.cloud.aiplatform.v1beta1.IBatchReadFeatureValuesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IBatchReadFeatureValuesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2664,7 +2664,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   exportFeatureValues(
-    request: protos.google.cloud.aiplatform.v1beta1.IExportFeatureValuesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IExportFeatureValuesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2731,7 +2731,7 @@ export class FeaturestoreServiceClient {
    * const [response] = await operation.promise();
    */
   exportFeatureValues(
-    request: protos.google.cloud.aiplatform.v1beta1.IExportFeatureValuesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IExportFeatureValuesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2816,7 +2816,7 @@ export class FeaturestoreServiceClient {
     >;
   }
   listFeaturestores(
-    request: protos.google.cloud.aiplatform.v1beta1.IListFeaturestoresRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListFeaturestoresRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2912,7 +2912,7 @@ export class FeaturestoreServiceClient {
    *   for more details and examples.
    */
   listFeaturestores(
-    request: protos.google.cloud.aiplatform.v1beta1.IListFeaturestoresRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListFeaturestoresRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3130,7 +3130,7 @@ export class FeaturestoreServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IFeaturestore>;
   }
   listEntityTypes(
-    request: protos.google.cloud.aiplatform.v1beta1.IListEntityTypesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListEntityTypesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3226,7 +3226,7 @@ export class FeaturestoreServiceClient {
    *   for more details and examples.
    */
   listEntityTypes(
-    request: protos.google.cloud.aiplatform.v1beta1.IListEntityTypesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListEntityTypesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3444,7 +3444,7 @@ export class FeaturestoreServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IEntityType>;
   }
   listFeatures(
-    request: protos.google.cloud.aiplatform.v1beta1.IListFeaturesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListFeaturesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3547,7 +3547,7 @@ export class FeaturestoreServiceClient {
    *   for more details and examples.
    */
   listFeatures(
-    request: protos.google.cloud.aiplatform.v1beta1.IListFeaturesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListFeaturesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3779,7 +3779,7 @@ export class FeaturestoreServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IFeature>;
   }
   searchFeatures(
-    request: protos.google.cloud.aiplatform.v1beta1.ISearchFeaturesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ISearchFeaturesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3905,7 +3905,7 @@ export class FeaturestoreServiceClient {
    *   for more details and examples.
    */
   searchFeatures(
-    request: protos.google.cloud.aiplatform.v1beta1.ISearchFeaturesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ISearchFeaturesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/index_endpoint_service_client.ts b/src/v1beta1/index_endpoint_service_client.ts
index 78cc7d30..308ff6ce 100644
--- a/src/v1beta1/index_endpoint_service_client.ts
+++ b/src/v1beta1/index_endpoint_service_client.ts
@@ -468,7 +468,7 @@ export class IndexEndpointServiceClient {
   // -- Service calls --
   // -------------------
   getIndexEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetIndexEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetIndexEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -521,7 +521,7 @@ export class IndexEndpointServiceClient {
    * const [response] = await client.getIndexEndpoint(request);
    */
   getIndexEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetIndexEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetIndexEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -567,7 +567,7 @@ export class IndexEndpointServiceClient {
     return this.innerApiCalls.getIndexEndpoint(request, options, callback);
   }
   updateIndexEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateIndexEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateIndexEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -620,7 +620,7 @@ export class IndexEndpointServiceClient {
    * const [response] = await client.updateIndexEndpoint(request);
    */
   updateIndexEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateIndexEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateIndexEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -667,7 +667,7 @@ export class IndexEndpointServiceClient {
   }
 
   createIndexEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateIndexEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateIndexEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -726,7 +726,7 @@ export class IndexEndpointServiceClient {
    * const [response] = await operation.promise();
    */
   createIndexEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateIndexEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateIndexEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -811,7 +811,7 @@ export class IndexEndpointServiceClient {
     >;
   }
   deleteIndexEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteIndexEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteIndexEndpointRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -869,7 +869,7 @@ export class IndexEndpointServiceClient {
    * const [response] = await operation.promise();
    */
   deleteIndexEndpoint(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteIndexEndpointRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteIndexEndpointRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -954,7 +954,7 @@ export class IndexEndpointServiceClient {
     >;
   }
   deployIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeployIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeployIndexRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1016,7 +1016,7 @@ export class IndexEndpointServiceClient {
    * const [response] = await operation.promise();
    */
   deployIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeployIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeployIndexRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1101,7 +1101,7 @@ export class IndexEndpointServiceClient {
     >;
   }
   undeployIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.IUndeployIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUndeployIndexRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1162,7 +1162,7 @@ export class IndexEndpointServiceClient {
    * const [response] = await operation.promise();
    */
   undeployIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.IUndeployIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUndeployIndexRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1247,7 +1247,7 @@ export class IndexEndpointServiceClient {
     >;
   }
   listIndexEndpoints(
-    request: protos.google.cloud.aiplatform.v1beta1.IListIndexEndpointsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListIndexEndpointsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1327,7 +1327,7 @@ export class IndexEndpointServiceClient {
    *   for more details and examples.
    */
   listIndexEndpoints(
-    request: protos.google.cloud.aiplatform.v1beta1.IListIndexEndpointsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListIndexEndpointsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/index_service_client.ts b/src/v1beta1/index_service_client.ts
index ac00fa2c..434d7346 100644
--- a/src/v1beta1/index_service_client.ts
+++ b/src/v1beta1/index_service_client.ts
@@ -454,7 +454,7 @@ export class IndexServiceClient {
   // -- Service calls --
   // -------------------
   getIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetIndexRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -504,7 +504,7 @@ export class IndexServiceClient {
    * const [response] = await client.getIndex(request);
    */
   getIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetIndexRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -548,7 +548,7 @@ export class IndexServiceClient {
   }
 
   createIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateIndexRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -607,7 +607,7 @@ export class IndexServiceClient {
    * const [response] = await operation.promise();
    */
   createIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateIndexRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -692,7 +692,7 @@ export class IndexServiceClient {
     >;
   }
   updateIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateIndexRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -751,7 +751,7 @@ export class IndexServiceClient {
    * const [response] = await operation.promise();
    */
   updateIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateIndexRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -836,7 +836,7 @@ export class IndexServiceClient {
     >;
   }
   deleteIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteIndexRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -896,7 +896,7 @@ export class IndexServiceClient {
    * const [response] = await operation.promise();
    */
   deleteIndex(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteIndexRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteIndexRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -981,7 +981,7 @@ export class IndexServiceClient {
     >;
   }
   listIndexes(
-    request: protos.google.cloud.aiplatform.v1beta1.IListIndexesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListIndexesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1044,7 +1044,7 @@ export class IndexServiceClient {
    *   for more details and examples.
    */
   listIndexes(
-    request: protos.google.cloud.aiplatform.v1beta1.IListIndexesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListIndexesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/job_service_client.ts b/src/v1beta1/job_service_client.ts
index 5ee75240..0de27fd6 100644
--- a/src/v1beta1/job_service_client.ts
+++ b/src/v1beta1/job_service_client.ts
@@ -556,7 +556,7 @@ export class JobServiceClient {
   // -- Service calls --
   // -------------------
   createCustomJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateCustomJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -611,7 +611,7 @@ export class JobServiceClient {
    * const [response] = await client.createCustomJob(request);
    */
   createCustomJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateCustomJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -657,7 +657,7 @@ export class JobServiceClient {
     return this.innerApiCalls.createCustomJob(request, options, callback);
   }
   getCustomJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetCustomJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -707,7 +707,7 @@ export class JobServiceClient {
    * const [response] = await client.getCustomJob(request);
    */
   getCustomJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetCustomJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -750,7 +750,7 @@ export class JobServiceClient {
     return this.innerApiCalls.getCustomJob(request, options, callback);
   }
   cancelCustomJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelCustomJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -812,7 +812,7 @@ export class JobServiceClient {
    * const [response] = await client.cancelCustomJob(request);
    */
   cancelCustomJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelCustomJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -858,7 +858,7 @@ export class JobServiceClient {
     return this.innerApiCalls.cancelCustomJob(request, options, callback);
   }
   createDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateDataLabelingJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -912,7 +912,7 @@ export class JobServiceClient {
    * const [response] = await client.createDataLabelingJob(request);
    */
   createDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateDataLabelingJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -958,7 +958,7 @@ export class JobServiceClient {
     return this.innerApiCalls.createDataLabelingJob(request, options, callback);
   }
   getDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetDataLabelingJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1011,7 +1011,7 @@ export class JobServiceClient {
    * const [response] = await client.getDataLabelingJob(request);
    */
   getDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetDataLabelingJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1057,7 +1057,7 @@ export class JobServiceClient {
     return this.innerApiCalls.getDataLabelingJob(request, options, callback);
   }
   cancelDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelDataLabelingJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1110,7 +1110,7 @@ export class JobServiceClient {
    * const [response] = await client.cancelDataLabelingJob(request);
    */
   cancelDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelDataLabelingJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1156,7 +1156,7 @@ export class JobServiceClient {
     return this.innerApiCalls.cancelDataLabelingJob(request, options, callback);
   }
   createHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateHyperparameterTuningJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1210,7 +1210,7 @@ export class JobServiceClient {
    * const [response] = await client.createHyperparameterTuningJob(request);
    */
   createHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateHyperparameterTuningJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1260,7 +1260,7 @@ export class JobServiceClient {
     );
   }
   getHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetHyperparameterTuningJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1313,7 +1313,7 @@ export class JobServiceClient {
    * const [response] = await client.getHyperparameterTuningJob(request);
    */
   getHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetHyperparameterTuningJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1363,7 +1363,7 @@ export class JobServiceClient {
     );
   }
   cancelHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelHyperparameterTuningJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1425,7 +1425,7 @@ export class JobServiceClient {
    * const [response] = await client.cancelHyperparameterTuningJob(request);
    */
   cancelHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelHyperparameterTuningJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1475,7 +1475,7 @@ export class JobServiceClient {
     );
   }
   createBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateBatchPredictionJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1530,7 +1530,7 @@ export class JobServiceClient {
    * const [response] = await client.createBatchPredictionJob(request);
    */
   createBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateBatchPredictionJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1580,7 +1580,7 @@ export class JobServiceClient {
     );
   }
   getBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetBatchPredictionJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1633,7 +1633,7 @@ export class JobServiceClient {
    * const [response] = await client.getBatchPredictionJob(request);
    */
   getBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetBatchPredictionJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1679,7 +1679,7 @@ export class JobServiceClient {
     return this.innerApiCalls.getBatchPredictionJob(request, options, callback);
   }
   cancelBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelBatchPredictionJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1741,7 +1741,7 @@ export class JobServiceClient {
    * const [response] = await client.cancelBatchPredictionJob(request);
    */
   cancelBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelBatchPredictionJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1791,7 +1791,7 @@ export class JobServiceClient {
     );
   }
   createModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateModelDeploymentMonitoringJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1846,7 +1846,7 @@ export class JobServiceClient {
    * const [response] = await client.createModelDeploymentMonitoringJob(request);
    */
   createModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateModelDeploymentMonitoringJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1896,7 +1896,7 @@ export class JobServiceClient {
     );
   }
   getModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetModelDeploymentMonitoringJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1949,7 +1949,7 @@ export class JobServiceClient {
    * const [response] = await client.getModelDeploymentMonitoringJob(request);
    */
   getModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetModelDeploymentMonitoringJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1999,7 +1999,7 @@ export class JobServiceClient {
     );
   }
   pauseModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IPauseModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IPauseModelDeploymentMonitoringJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2054,7 +2054,7 @@ export class JobServiceClient {
    * const [response] = await client.pauseModelDeploymentMonitoringJob(request);
    */
   pauseModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IPauseModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IPauseModelDeploymentMonitoringJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2104,7 +2104,7 @@ export class JobServiceClient {
     );
   }
   resumeModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IResumeModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IResumeModelDeploymentMonitoringJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2159,7 +2159,7 @@ export class JobServiceClient {
    * const [response] = await client.resumeModelDeploymentMonitoringJob(request);
    */
   resumeModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IResumeModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IResumeModelDeploymentMonitoringJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2210,7 +2210,7 @@ export class JobServiceClient {
   }
 
   deleteCustomJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteCustomJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2268,7 +2268,7 @@ export class JobServiceClient {
    * const [response] = await operation.promise();
    */
   deleteCustomJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteCustomJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteCustomJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2353,7 +2353,7 @@ export class JobServiceClient {
     >;
   }
   deleteDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteDataLabelingJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2411,7 +2411,7 @@ export class JobServiceClient {
    * const [response] = await operation.promise();
    */
   deleteDataLabelingJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteDataLabelingJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteDataLabelingJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2496,7 +2496,7 @@ export class JobServiceClient {
     >;
   }
   deleteHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteHyperparameterTuningJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2554,7 +2554,7 @@ export class JobServiceClient {
    * const [response] = await operation.promise();
    */
   deleteHyperparameterTuningJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteHyperparameterTuningJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteHyperparameterTuningJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2643,7 +2643,7 @@ export class JobServiceClient {
     >;
   }
   deleteBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteBatchPredictionJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2702,7 +2702,7 @@ export class JobServiceClient {
    * const [response] = await operation.promise();
    */
   deleteBatchPredictionJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteBatchPredictionJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteBatchPredictionJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2791,7 +2791,7 @@ export class JobServiceClient {
     >;
   }
   updateModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateModelDeploymentMonitoringJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2850,7 +2850,7 @@ export class JobServiceClient {
    * const [response] = await operation.promise();
    */
   updateModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateModelDeploymentMonitoringJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2940,7 +2940,7 @@ export class JobServiceClient {
     >;
   }
   deleteModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteModelDeploymentMonitoringJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2998,7 +2998,7 @@ export class JobServiceClient {
    * const [response] = await operation.promise();
    */
   deleteModelDeploymentMonitoringJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteModelDeploymentMonitoringJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteModelDeploymentMonitoringJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -3087,7 +3087,7 @@ export class JobServiceClient {
     >;
   }
   listCustomJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListCustomJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListCustomJobsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3166,7 +3166,7 @@ export class JobServiceClient {
    *   for more details and examples.
    */
   listCustomJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListCustomJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListCustomJobsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3350,7 +3350,7 @@ export class JobServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.ICustomJob>;
   }
   listDataLabelingJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListDataLabelingJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListDataLabelingJobsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3433,7 +3433,7 @@ export class JobServiceClient {
    *   for more details and examples.
    */
   listDataLabelingJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListDataLabelingJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListDataLabelingJobsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3625,7 +3625,7 @@ export class JobServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IDataLabelingJob>;
   }
   listHyperparameterTuningJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListHyperparameterTuningJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListHyperparameterTuningJobsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3704,7 +3704,7 @@ export class JobServiceClient {
    *   for more details and examples.
    */
   listHyperparameterTuningJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListHyperparameterTuningJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListHyperparameterTuningJobsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3892,7 +3892,7 @@ export class JobServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IHyperparameterTuningJob>;
   }
   listBatchPredictionJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListBatchPredictionJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListBatchPredictionJobsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3973,7 +3973,7 @@ export class JobServiceClient {
    *   for more details and examples.
    */
   listBatchPredictionJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListBatchPredictionJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListBatchPredictionJobsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -4165,7 +4165,7 @@ export class JobServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IBatchPredictionJob>;
   }
   searchModelDeploymentMonitoringStatsAnomalies(
-    request: protos.google.cloud.aiplatform.v1beta1.ISearchModelDeploymentMonitoringStatsAnomaliesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ISearchModelDeploymentMonitoringStatsAnomaliesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -4240,7 +4240,7 @@ export class JobServiceClient {
    *   for more details and examples.
    */
   searchModelDeploymentMonitoringStatsAnomalies(
-    request: protos.google.cloud.aiplatform.v1beta1.ISearchModelDeploymentMonitoringStatsAnomaliesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ISearchModelDeploymentMonitoringStatsAnomaliesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -4426,7 +4426,7 @@ export class JobServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IModelMonitoringStatsAnomalies>;
   }
   listModelDeploymentMonitoringJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListModelDeploymentMonitoringJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListModelDeploymentMonitoringJobsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -4486,7 +4486,7 @@ export class JobServiceClient {
    *   for more details and examples.
    */
   listModelDeploymentMonitoringJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListModelDeploymentMonitoringJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListModelDeploymentMonitoringJobsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/metadata_service_client.ts b/src/v1beta1/metadata_service_client.ts
index e84182fb..463ecbf6 100644
--- a/src/v1beta1/metadata_service_client.ts
+++ b/src/v1beta1/metadata_service_client.ts
@@ -498,7 +498,7 @@ export class MetadataServiceClient {
   // -- Service calls --
   // -------------------
   getMetadataStore(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetMetadataStoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetMetadataStoreRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -551,7 +551,7 @@ export class MetadataServiceClient {
    * const [response] = await client.getMetadataStore(request);
    */
   getMetadataStore(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetMetadataStoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetMetadataStoreRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -597,7 +597,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.getMetadataStore(request, options, callback);
   }
   createArtifact(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateArtifactRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateArtifactRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -658,7 +658,7 @@ export class MetadataServiceClient {
    * const [response] = await client.createArtifact(request);
    */
   createArtifact(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateArtifactRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateArtifactRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -701,7 +701,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.createArtifact(request, options, callback);
   }
   getArtifact(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetArtifactRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetArtifactRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -751,7 +751,7 @@ export class MetadataServiceClient {
    * const [response] = await client.getArtifact(request);
    */
   getArtifact(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetArtifactRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetArtifactRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -794,7 +794,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.getArtifact(request, options, callback);
   }
   updateArtifact(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateArtifactRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateArtifactRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -851,7 +851,7 @@ export class MetadataServiceClient {
    * const [response] = await client.updateArtifact(request);
    */
   updateArtifact(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateArtifactRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateArtifactRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -894,7 +894,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.updateArtifact(request, options, callback);
   }
   createContext(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateContextRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateContextRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -955,7 +955,7 @@ export class MetadataServiceClient {
    * const [response] = await client.createContext(request);
    */
   createContext(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateContextRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateContextRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -998,7 +998,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.createContext(request, options, callback);
   }
   getContext(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetContextRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetContextRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1048,7 +1048,7 @@ export class MetadataServiceClient {
    * const [response] = await client.getContext(request);
    */
   getContext(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetContextRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetContextRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1091,7 +1091,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.getContext(request, options, callback);
   }
   updateContext(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateContextRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateContextRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1148,7 +1148,7 @@ export class MetadataServiceClient {
    * const [response] = await client.updateContext(request);
    */
   updateContext(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateContextRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateContextRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1191,7 +1191,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.updateContext(request, options, callback);
   }
   addContextArtifactsAndExecutions(
-    request: protos.google.cloud.aiplatform.v1beta1.IAddContextArtifactsAndExecutionsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IAddContextArtifactsAndExecutionsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1258,7 +1258,7 @@ export class MetadataServiceClient {
    * const [response] = await client.addContextArtifactsAndExecutions(request);
    */
   addContextArtifactsAndExecutions(
-    request: protos.google.cloud.aiplatform.v1beta1.IAddContextArtifactsAndExecutionsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IAddContextArtifactsAndExecutionsRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1308,7 +1308,7 @@ export class MetadataServiceClient {
     );
   }
   addContextChildren(
-    request: protos.google.cloud.aiplatform.v1beta1.IAddContextChildrenRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IAddContextChildrenRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1368,7 +1368,7 @@ export class MetadataServiceClient {
    * const [response] = await client.addContextChildren(request);
    */
   addContextChildren(
-    request: protos.google.cloud.aiplatform.v1beta1.IAddContextChildrenRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IAddContextChildrenRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1414,7 +1414,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.addContextChildren(request, options, callback);
   }
   queryContextLineageSubgraph(
-    request: protos.google.cloud.aiplatform.v1beta1.IQueryContextLineageSubgraphRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IQueryContextLineageSubgraphRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1473,7 +1473,7 @@ export class MetadataServiceClient {
    * const [response] = await client.queryContextLineageSubgraph(request);
    */
   queryContextLineageSubgraph(
-    request: protos.google.cloud.aiplatform.v1beta1.IQueryContextLineageSubgraphRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IQueryContextLineageSubgraphRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1523,7 +1523,7 @@ export class MetadataServiceClient {
     );
   }
   createExecution(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateExecutionRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateExecutionRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1588,7 +1588,7 @@ export class MetadataServiceClient {
    * const [response] = await client.createExecution(request);
    */
   createExecution(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateExecutionRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateExecutionRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1634,7 +1634,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.createExecution(request, options, callback);
   }
   getExecution(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetExecutionRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetExecutionRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1684,7 +1684,7 @@ export class MetadataServiceClient {
    * const [response] = await client.getExecution(request);
    */
   getExecution(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetExecutionRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetExecutionRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1727,7 +1727,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.getExecution(request, options, callback);
   }
   updateExecution(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateExecutionRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateExecutionRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1787,7 +1787,7 @@ export class MetadataServiceClient {
    * const [response] = await client.updateExecution(request);
    */
   updateExecution(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateExecutionRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateExecutionRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1833,7 +1833,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.updateExecution(request, options, callback);
   }
   addExecutionEvents(
-    request: protos.google.cloud.aiplatform.v1beta1.IAddExecutionEventsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IAddExecutionEventsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1892,7 +1892,7 @@ export class MetadataServiceClient {
    * const [response] = await client.addExecutionEvents(request);
    */
   addExecutionEvents(
-    request: protos.google.cloud.aiplatform.v1beta1.IAddExecutionEventsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IAddExecutionEventsRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1938,7 +1938,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.addExecutionEvents(request, options, callback);
   }
   queryExecutionInputsAndOutputs(
-    request: protos.google.cloud.aiplatform.v1beta1.IQueryExecutionInputsAndOutputsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IQueryExecutionInputsAndOutputsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1994,7 +1994,7 @@ export class MetadataServiceClient {
    * const [response] = await client.queryExecutionInputsAndOutputs(request);
    */
   queryExecutionInputsAndOutputs(
-    request: protos.google.cloud.aiplatform.v1beta1.IQueryExecutionInputsAndOutputsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IQueryExecutionInputsAndOutputsRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2044,7 +2044,7 @@ export class MetadataServiceClient {
     );
   }
   createMetadataSchema(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateMetadataSchemaRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateMetadataSchemaRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2109,7 +2109,7 @@ export class MetadataServiceClient {
    * const [response] = await client.createMetadataSchema(request);
    */
   createMetadataSchema(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateMetadataSchemaRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateMetadataSchemaRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2155,7 +2155,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.createMetadataSchema(request, options, callback);
   }
   getMetadataSchema(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetMetadataSchemaRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetMetadataSchemaRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2208,7 +2208,7 @@ export class MetadataServiceClient {
    * const [response] = await client.getMetadataSchema(request);
    */
   getMetadataSchema(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetMetadataSchemaRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetMetadataSchemaRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2254,7 +2254,7 @@ export class MetadataServiceClient {
     return this.innerApiCalls.getMetadataSchema(request, options, callback);
   }
   queryArtifactLineageSubgraph(
-    request: protos.google.cloud.aiplatform.v1beta1.IQueryArtifactLineageSubgraphRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IQueryArtifactLineageSubgraphRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2341,7 +2341,7 @@ export class MetadataServiceClient {
    * const [response] = await client.queryArtifactLineageSubgraph(request);
    */
   queryArtifactLineageSubgraph(
-    request: protos.google.cloud.aiplatform.v1beta1.IQueryArtifactLineageSubgraphRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IQueryArtifactLineageSubgraphRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2392,7 +2392,7 @@ export class MetadataServiceClient {
   }
 
   createMetadataStore(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateMetadataStoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateMetadataStoreRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2461,7 +2461,7 @@ export class MetadataServiceClient {
    * const [response] = await operation.promise();
    */
   createMetadataStore(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateMetadataStoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateMetadataStoreRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2546,7 +2546,7 @@ export class MetadataServiceClient {
     >;
   }
   deleteMetadataStore(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteMetadataStoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteMetadataStoreRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2608,7 +2608,7 @@ export class MetadataServiceClient {
    * const [response] = await operation.promise();
    */
   deleteMetadataStore(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteMetadataStoreRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteMetadataStoreRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2693,7 +2693,7 @@ export class MetadataServiceClient {
     >;
   }
   deleteContext(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteContextRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteContextRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2756,7 +2756,7 @@ export class MetadataServiceClient {
    * const [response] = await operation.promise();
    */
   deleteContext(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteContextRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteContextRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2841,7 +2841,7 @@ export class MetadataServiceClient {
     >;
   }
   listMetadataStores(
-    request: protos.google.cloud.aiplatform.v1beta1.IListMetadataStoresRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListMetadataStoresRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2906,7 +2906,7 @@ export class MetadataServiceClient {
    *   for more details and examples.
    */
   listMetadataStores(
-    request: protos.google.cloud.aiplatform.v1beta1.IListMetadataStoresRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListMetadataStoresRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3062,7 +3062,7 @@ export class MetadataServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IMetadataStore>;
   }
   listArtifacts(
-    request: protos.google.cloud.aiplatform.v1beta1.IListArtifactsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListArtifactsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3153,7 +3153,7 @@ export class MetadataServiceClient {
    *   for more details and examples.
    */
   listArtifacts(
-    request: protos.google.cloud.aiplatform.v1beta1.IListArtifactsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListArtifactsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3361,7 +3361,7 @@ export class MetadataServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IArtifact>;
   }
   listContexts(
-    request: protos.google.cloud.aiplatform.v1beta1.IListContextsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListContextsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3456,7 +3456,7 @@ export class MetadataServiceClient {
    *   for more details and examples.
    */
   listContexts(
-    request: protos.google.cloud.aiplatform.v1beta1.IListContextsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListContextsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3672,7 +3672,7 @@ export class MetadataServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IContext>;
   }
   listExecutions(
-    request: protos.google.cloud.aiplatform.v1beta1.IListExecutionsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListExecutionsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3762,7 +3762,7 @@ export class MetadataServiceClient {
    *   for more details and examples.
    */
   listExecutions(
-    request: protos.google.cloud.aiplatform.v1beta1.IListExecutionsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListExecutionsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3968,7 +3968,7 @@ export class MetadataServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IExecution>;
   }
   listMetadataSchemas(
-    request: protos.google.cloud.aiplatform.v1beta1.IListMetadataSchemasRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListMetadataSchemasRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -4035,7 +4035,7 @@ export class MetadataServiceClient {
    *   for more details and examples.
    */
   listMetadataSchemas(
-    request: protos.google.cloud.aiplatform.v1beta1.IListMetadataSchemasRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListMetadataSchemasRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/migration_service_client.ts b/src/v1beta1/migration_service_client.ts
index a18a1d95..382b2322 100644
--- a/src/v1beta1/migration_service_client.ts
+++ b/src/v1beta1/migration_service_client.ts
@@ -434,7 +434,7 @@ export class MigrationServiceClient {
   // -------------------
 
   batchMigrateResources(
-    request: protos.google.cloud.aiplatform.v1beta1.IBatchMigrateResourcesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IBatchMigrateResourcesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -496,7 +496,7 @@ export class MigrationServiceClient {
    * const [response] = await operation.promise();
    */
   batchMigrateResources(
-    request: protos.google.cloud.aiplatform.v1beta1.IBatchMigrateResourcesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IBatchMigrateResourcesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -581,7 +581,7 @@ export class MigrationServiceClient {
     >;
   }
   searchMigratableResources(
-    request: protos.google.cloud.aiplatform.v1beta1.ISearchMigratableResourcesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ISearchMigratableResourcesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -656,7 +656,7 @@ export class MigrationServiceClient {
    *   for more details and examples.
    */
   searchMigratableResources(
-    request: protos.google.cloud.aiplatform.v1beta1.ISearchMigratableResourcesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ISearchMigratableResourcesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/model_service_client.ts b/src/v1beta1/model_service_client.ts
index 57405b6b..dc58b73a 100644
--- a/src/v1beta1/model_service_client.ts
+++ b/src/v1beta1/model_service_client.ts
@@ -469,7 +469,7 @@ export class ModelServiceClient {
   // -- Service calls --
   // -------------------
   getModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -518,7 +518,7 @@ export class ModelServiceClient {
    * const [response] = await client.getModel(request);
    */
   getModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -561,7 +561,7 @@ export class ModelServiceClient {
     return this.innerApiCalls.getModel(request, options, callback);
   }
   updateModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -612,7 +612,7 @@ export class ModelServiceClient {
    * const [response] = await client.updateModel(request);
    */
   updateModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -655,7 +655,7 @@ export class ModelServiceClient {
     return this.innerApiCalls.updateModel(request, options, callback);
   }
   getModelEvaluation(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetModelEvaluationRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetModelEvaluationRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -708,7 +708,7 @@ export class ModelServiceClient {
    * const [response] = await client.getModelEvaluation(request);
    */
   getModelEvaluation(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetModelEvaluationRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetModelEvaluationRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -754,7 +754,7 @@ export class ModelServiceClient {
     return this.innerApiCalls.getModelEvaluation(request, options, callback);
   }
   getModelEvaluationSlice(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetModelEvaluationSliceRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetModelEvaluationSliceRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -807,7 +807,7 @@ export class ModelServiceClient {
    * const [response] = await client.getModelEvaluationSlice(request);
    */
   getModelEvaluationSlice(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetModelEvaluationSliceRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetModelEvaluationSliceRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -858,7 +858,7 @@ export class ModelServiceClient {
   }
 
   uploadModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IUploadModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUploadModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -917,7 +917,7 @@ export class ModelServiceClient {
    * const [response] = await operation.promise();
    */
   uploadModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IUploadModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUploadModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1002,7 +1002,7 @@ export class ModelServiceClient {
     >;
   }
   deleteModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1061,7 +1061,7 @@ export class ModelServiceClient {
    * const [response] = await operation.promise();
    */
   deleteModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1146,7 +1146,7 @@ export class ModelServiceClient {
     >;
   }
   exportModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IExportModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IExportModelRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1207,7 +1207,7 @@ export class ModelServiceClient {
    * const [response] = await operation.promise();
    */
   exportModel(
-    request: protos.google.cloud.aiplatform.v1beta1.IExportModelRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IExportModelRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1292,7 +1292,7 @@ export class ModelServiceClient {
     >;
   }
   listModels(
-    request: protos.google.cloud.aiplatform.v1beta1.IListModelsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListModelsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1369,7 +1369,7 @@ export class ModelServiceClient {
    *   for more details and examples.
    */
   listModels(
-    request: protos.google.cloud.aiplatform.v1beta1.IListModelsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListModelsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -1549,7 +1549,7 @@ export class ModelServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IModel>;
   }
   listModelEvaluations(
-    request: protos.google.cloud.aiplatform.v1beta1.IListModelEvaluationsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListModelEvaluationsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1612,7 +1612,7 @@ export class ModelServiceClient {
    *   for more details and examples.
    */
   listModelEvaluations(
-    request: protos.google.cloud.aiplatform.v1beta1.IListModelEvaluationsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListModelEvaluationsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -1764,7 +1764,7 @@ export class ModelServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IModelEvaluation>;
   }
   listModelEvaluationSlices(
-    request: protos.google.cloud.aiplatform.v1beta1.IListModelEvaluationSlicesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListModelEvaluationSlicesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1830,7 +1830,7 @@ export class ModelServiceClient {
    *   for more details and examples.
    */
   listModelEvaluationSlices(
-    request: protos.google.cloud.aiplatform.v1beta1.IListModelEvaluationSlicesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListModelEvaluationSlicesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/pipeline_service_client.ts b/src/v1beta1/pipeline_service_client.ts
index 085a3413..e8c91d3c 100644
--- a/src/v1beta1/pipeline_service_client.ts
+++ b/src/v1beta1/pipeline_service_client.ts
@@ -459,7 +459,7 @@ export class PipelineServiceClient {
   // -- Service calls --
   // -------------------
   createTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTrainingPipelineRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -514,7 +514,7 @@ export class PipelineServiceClient {
    * const [response] = await client.createTrainingPipeline(request);
    */
   createTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTrainingPipelineRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -564,7 +564,7 @@ export class PipelineServiceClient {
     );
   }
   getTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTrainingPipelineRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -617,7 +617,7 @@ export class PipelineServiceClient {
    * const [response] = await client.getTrainingPipeline(request);
    */
   getTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTrainingPipelineRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -663,7 +663,7 @@ export class PipelineServiceClient {
     return this.innerApiCalls.getTrainingPipeline(request, options, callback);
   }
   cancelTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelTrainingPipelineRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -725,7 +725,7 @@ export class PipelineServiceClient {
    * const [response] = await client.cancelTrainingPipeline(request);
    */
   cancelTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelTrainingPipelineRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -775,7 +775,7 @@ export class PipelineServiceClient {
     );
   }
   createPipelineJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreatePipelineJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreatePipelineJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -836,7 +836,7 @@ export class PipelineServiceClient {
    * const [response] = await client.createPipelineJob(request);
    */
   createPipelineJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreatePipelineJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreatePipelineJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -882,7 +882,7 @@ export class PipelineServiceClient {
     return this.innerApiCalls.createPipelineJob(request, options, callback);
   }
   getPipelineJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetPipelineJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetPipelineJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -932,7 +932,7 @@ export class PipelineServiceClient {
    * const [response] = await client.getPipelineJob(request);
    */
   getPipelineJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetPipelineJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetPipelineJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -975,7 +975,7 @@ export class PipelineServiceClient {
     return this.innerApiCalls.getPipelineJob(request, options, callback);
   }
   cancelPipelineJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelPipelineJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelPipelineJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1037,7 +1037,7 @@ export class PipelineServiceClient {
    * const [response] = await client.cancelPipelineJob(request);
    */
   cancelPipelineJob(
-    request: protos.google.cloud.aiplatform.v1beta1.ICancelPipelineJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICancelPipelineJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1084,7 +1084,7 @@ export class PipelineServiceClient {
   }
 
   deleteTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTrainingPipelineRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1142,7 +1142,7 @@ export class PipelineServiceClient {
    * const [response] = await operation.promise();
    */
   deleteTrainingPipeline(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTrainingPipelineRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTrainingPipelineRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1231,7 +1231,7 @@ export class PipelineServiceClient {
     >;
   }
   deletePipelineJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeletePipelineJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeletePipelineJobRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1289,7 +1289,7 @@ export class PipelineServiceClient {
    * const [response] = await operation.promise();
    */
   deletePipelineJob(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeletePipelineJobRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeletePipelineJobRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1374,7 +1374,7 @@ export class PipelineServiceClient {
     >;
   }
   listTrainingPipelines(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTrainingPipelinesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTrainingPipelinesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1452,7 +1452,7 @@ export class PipelineServiceClient {
    *   for more details and examples.
    */
   listTrainingPipelines(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTrainingPipelinesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTrainingPipelinesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -1634,7 +1634,7 @@ export class PipelineServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.ITrainingPipeline>;
   }
   listPipelineJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListPipelineJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListPipelineJobsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1706,7 +1706,7 @@ export class PipelineServiceClient {
    *   for more details and examples.
    */
   listPipelineJobs(
-    request: protos.google.cloud.aiplatform.v1beta1.IListPipelineJobsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListPipelineJobsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/prediction_service_client.ts b/src/v1beta1/prediction_service_client.ts
index 6a5d82ce..09fb7c94 100644
--- a/src/v1beta1/prediction_service_client.ts
+++ b/src/v1beta1/prediction_service_client.ts
@@ -372,7 +372,7 @@ export class PredictionServiceClient {
   // -- Service calls --
   // -------------------
   predict(
-    request: protos.google.cloud.aiplatform.v1beta1.IPredictRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IPredictRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -433,7 +433,7 @@ export class PredictionServiceClient {
    * const [response] = await client.predict(request);
    */
   predict(
-    request: protos.google.cloud.aiplatform.v1beta1.IPredictRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IPredictRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -474,7 +474,7 @@ export class PredictionServiceClient {
     return this.innerApiCalls.predict(request, options, callback);
   }
   explain(
-    request: protos.google.cloud.aiplatform.v1beta1.IExplainRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IExplainRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -556,7 +556,7 @@ export class PredictionServiceClient {
    * const [response] = await client.explain(request);
    */
   explain(
-    request: protos.google.cloud.aiplatform.v1beta1.IExplainRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IExplainRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
diff --git a/src/v1beta1/specialist_pool_service_client.ts b/src/v1beta1/specialist_pool_service_client.ts
index 9a3e2b77..cf5c828d 100644
--- a/src/v1beta1/specialist_pool_service_client.ts
+++ b/src/v1beta1/specialist_pool_service_client.ts
@@ -461,7 +461,7 @@ export class SpecialistPoolServiceClient {
   // -- Service calls --
   // -------------------
   getSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetSpecialistPoolRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -514,7 +514,7 @@ export class SpecialistPoolServiceClient {
    * const [response] = await client.getSpecialistPool(request);
    */
   getSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetSpecialistPoolRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -561,7 +561,7 @@ export class SpecialistPoolServiceClient {
   }
 
   createSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateSpecialistPoolRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -620,7 +620,7 @@ export class SpecialistPoolServiceClient {
    * const [response] = await operation.promise();
    */
   createSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateSpecialistPoolRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -705,7 +705,7 @@ export class SpecialistPoolServiceClient {
     >;
   }
   deleteSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteSpecialistPoolRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -766,7 +766,7 @@ export class SpecialistPoolServiceClient {
    * const [response] = await operation.promise();
    */
   deleteSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteSpecialistPoolRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -851,7 +851,7 @@ export class SpecialistPoolServiceClient {
     >;
   }
   updateSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateSpecialistPoolRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -909,7 +909,7 @@ export class SpecialistPoolServiceClient {
    * const [response] = await operation.promise();
    */
   updateSpecialistPool(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateSpecialistPoolRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateSpecialistPoolRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -994,7 +994,7 @@ export class SpecialistPoolServiceClient {
     >;
   }
   listSpecialistPools(
-    request: protos.google.cloud.aiplatform.v1beta1.IListSpecialistPoolsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListSpecialistPoolsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1055,7 +1055,7 @@ export class SpecialistPoolServiceClient {
    *   for more details and examples.
    */
   listSpecialistPools(
-    request: protos.google.cloud.aiplatform.v1beta1.IListSpecialistPoolsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListSpecialistPoolsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/tensorboard_service_client.ts b/src/v1beta1/tensorboard_service_client.ts
index 1d75a662..987a19f9 100644
--- a/src/v1beta1/tensorboard_service_client.ts
+++ b/src/v1beta1/tensorboard_service_client.ts
@@ -547,7 +547,7 @@ export class TensorboardServiceClient {
   // -- Service calls --
   // -------------------
   getTensorboard(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -597,7 +597,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.getTensorboard(request);
    */
   getTensorboard(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -640,7 +640,7 @@ export class TensorboardServiceClient {
     return this.innerApiCalls.getTensorboard(request, options, callback);
   }
   createTensorboardExperiment(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardExperimentRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardExperimentRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -701,7 +701,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.createTensorboardExperiment(request);
    */
   createTensorboardExperiment(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardExperimentRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardExperimentRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -751,7 +751,7 @@ export class TensorboardServiceClient {
     );
   }
   getTensorboardExperiment(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardExperimentRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardExperimentRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -804,7 +804,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.getTensorboardExperiment(request);
    */
   getTensorboardExperiment(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardExperimentRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardExperimentRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -854,7 +854,7 @@ export class TensorboardServiceClient {
     );
   }
   updateTensorboardExperiment(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardExperimentRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardExperimentRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -914,7 +914,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.updateTensorboardExperiment(request);
    */
   updateTensorboardExperiment(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardExperimentRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardExperimentRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -965,7 +965,7 @@ export class TensorboardServiceClient {
     );
   }
   createTensorboardRun(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardRunRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardRunRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1026,7 +1026,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.createTensorboardRun(request);
    */
   createTensorboardRun(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardRunRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardRunRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1072,7 +1072,7 @@ export class TensorboardServiceClient {
     return this.innerApiCalls.createTensorboardRun(request, options, callback);
   }
   getTensorboardRun(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardRunRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardRunRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1125,7 +1125,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.getTensorboardRun(request);
    */
   getTensorboardRun(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardRunRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardRunRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1171,7 +1171,7 @@ export class TensorboardServiceClient {
     return this.innerApiCalls.getTensorboardRun(request, options, callback);
   }
   updateTensorboardRun(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardRunRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardRunRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1231,7 +1231,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.updateTensorboardRun(request);
    */
   updateTensorboardRun(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardRunRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardRunRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1277,7 +1277,7 @@ export class TensorboardServiceClient {
     return this.innerApiCalls.updateTensorboardRun(request, options, callback);
   }
   createTensorboardTimeSeries(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardTimeSeriesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardTimeSeriesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1339,7 +1339,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.createTensorboardTimeSeries(request);
    */
   createTensorboardTimeSeries(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardTimeSeriesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardTimeSeriesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1389,7 +1389,7 @@ export class TensorboardServiceClient {
     );
   }
   getTensorboardTimeSeries(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardTimeSeriesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardTimeSeriesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1442,7 +1442,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.getTensorboardTimeSeries(request);
    */
   getTensorboardTimeSeries(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardTimeSeriesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTensorboardTimeSeriesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1492,7 +1492,7 @@ export class TensorboardServiceClient {
     );
   }
   updateTensorboardTimeSeries(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardTimeSeriesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardTimeSeriesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1553,7 +1553,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.updateTensorboardTimeSeries(request);
    */
   updateTensorboardTimeSeries(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardTimeSeriesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardTimeSeriesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1604,7 +1604,7 @@ export class TensorboardServiceClient {
     );
   }
   readTensorboardTimeSeriesData(
-    request: protos.google.cloud.aiplatform.v1beta1.IReadTensorboardTimeSeriesDataRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IReadTensorboardTimeSeriesDataRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1668,7 +1668,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.readTensorboardTimeSeriesData(request);
    */
   readTensorboardTimeSeriesData(
-    request: protos.google.cloud.aiplatform.v1beta1.IReadTensorboardTimeSeriesDataRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IReadTensorboardTimeSeriesDataRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1718,7 +1718,7 @@ export class TensorboardServiceClient {
     );
   }
   writeTensorboardRunData(
-    request: protos.google.cloud.aiplatform.v1beta1.IWriteTensorboardRunDataRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IWriteTensorboardRunDataRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1779,7 +1779,7 @@ export class TensorboardServiceClient {
    * const [response] = await client.writeTensorboardRunData(request);
    */
   writeTensorboardRunData(
-    request: protos.google.cloud.aiplatform.v1beta1.IWriteTensorboardRunDataRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IWriteTensorboardRunDataRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1872,7 +1872,7 @@ export class TensorboardServiceClient {
   }
 
   createTensorboard(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1931,7 +1931,7 @@ export class TensorboardServiceClient {
    * const [response] = await operation.promise();
    */
   createTensorboard(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTensorboardRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2016,7 +2016,7 @@ export class TensorboardServiceClient {
     >;
   }
   updateTensorboard(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2081,7 +2081,7 @@ export class TensorboardServiceClient {
    * const [response] = await operation.promise();
    */
   updateTensorboard(
-    request: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IUpdateTensorboardRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2166,7 +2166,7 @@ export class TensorboardServiceClient {
     >;
   }
   deleteTensorboard(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2224,7 +2224,7 @@ export class TensorboardServiceClient {
    * const [response] = await operation.promise();
    */
   deleteTensorboard(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2309,7 +2309,7 @@ export class TensorboardServiceClient {
     >;
   }
   deleteTensorboardExperiment(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardExperimentRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardExperimentRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2367,7 +2367,7 @@ export class TensorboardServiceClient {
    * const [response] = await operation.promise();
    */
   deleteTensorboardExperiment(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardExperimentRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardExperimentRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2456,7 +2456,7 @@ export class TensorboardServiceClient {
     >;
   }
   deleteTensorboardRun(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardRunRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardRunRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2514,7 +2514,7 @@ export class TensorboardServiceClient {
    * const [response] = await operation.promise();
    */
   deleteTensorboardRun(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardRunRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardRunRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2599,7 +2599,7 @@ export class TensorboardServiceClient {
     >;
   }
   deleteTensorboardTimeSeries(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardTimeSeriesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardTimeSeriesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2657,7 +2657,7 @@ export class TensorboardServiceClient {
    * const [response] = await operation.promise();
    */
   deleteTensorboardTimeSeries(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardTimeSeriesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTensorboardTimeSeriesRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -2746,7 +2746,7 @@ export class TensorboardServiceClient {
     >;
   }
   listTensorboards(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTensorboardsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTensorboardsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2818,7 +2818,7 @@ export class TensorboardServiceClient {
    *   for more details and examples.
    */
   listTensorboards(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTensorboardsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTensorboardsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -2988,7 +2988,7 @@ export class TensorboardServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.ITensorboard>;
   }
   listTensorboardExperiments(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTensorboardExperimentsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTensorboardExperimentsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3060,7 +3060,7 @@ export class TensorboardServiceClient {
    *   for more details and examples.
    */
   listTensorboardExperiments(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTensorboardExperimentsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTensorboardExperimentsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3234,7 +3234,7 @@ export class TensorboardServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.ITensorboardExperiment>;
   }
   listTensorboardRuns(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTensorboardRunsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTensorboardRunsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3306,7 +3306,7 @@ export class TensorboardServiceClient {
    *   for more details and examples.
    */
   listTensorboardRuns(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTensorboardRunsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTensorboardRunsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3476,7 +3476,7 @@ export class TensorboardServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.ITensorboardRun>;
   }
   listTensorboardTimeSeries(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTensorboardTimeSeriesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTensorboardTimeSeriesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3548,7 +3548,7 @@ export class TensorboardServiceClient {
    *   for more details and examples.
    */
   listTensorboardTimeSeries(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTensorboardTimeSeriesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTensorboardTimeSeriesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -3722,7 +3722,7 @@ export class TensorboardServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.ITensorboardTimeSeries>;
   }
   exportTensorboardTimeSeriesData(
-    request: protos.google.cloud.aiplatform.v1beta1.IExportTensorboardTimeSeriesDataRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IExportTensorboardTimeSeriesDataRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -3794,7 +3794,7 @@ export class TensorboardServiceClient {
    *   for more details and examples.
    */
   exportTensorboardTimeSeriesData(
-    request: protos.google.cloud.aiplatform.v1beta1.IExportTensorboardTimeSeriesDataRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IExportTensorboardTimeSeriesDataRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
diff --git a/src/v1beta1/vizier_service_client.ts b/src/v1beta1/vizier_service_client.ts
index d4c973b7..c2d34f55 100644
--- a/src/v1beta1/vizier_service_client.ts
+++ b/src/v1beta1/vizier_service_client.ts
@@ -466,7 +466,7 @@ export class VizierServiceClient {
   // -- Service calls --
   // -------------------
   createStudy(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateStudyRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateStudyRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -518,7 +518,7 @@ export class VizierServiceClient {
    * const [response] = await client.createStudy(request);
    */
   createStudy(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateStudyRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateStudyRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -561,7 +561,7 @@ export class VizierServiceClient {
     return this.innerApiCalls.createStudy(request, options, callback);
   }
   getStudy(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetStudyRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetStudyRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -610,7 +610,7 @@ export class VizierServiceClient {
    * const [response] = await client.getStudy(request);
    */
   getStudy(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetStudyRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetStudyRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -653,7 +653,7 @@ export class VizierServiceClient {
     return this.innerApiCalls.getStudy(request, options, callback);
   }
   deleteStudy(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteStudyRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteStudyRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -702,7 +702,7 @@ export class VizierServiceClient {
    * const [response] = await client.deleteStudy(request);
    */
   deleteStudy(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteStudyRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteStudyRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -745,7 +745,7 @@ export class VizierServiceClient {
     return this.innerApiCalls.deleteStudy(request, options, callback);
   }
   lookupStudy(
-    request: protos.google.cloud.aiplatform.v1beta1.ILookupStudyRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ILookupStudyRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -797,7 +797,7 @@ export class VizierServiceClient {
    * const [response] = await client.lookupStudy(request);
    */
   lookupStudy(
-    request: protos.google.cloud.aiplatform.v1beta1.ILookupStudyRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ILookupStudyRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -840,7 +840,7 @@ export class VizierServiceClient {
     return this.innerApiCalls.lookupStudy(request, options, callback);
   }
   createTrial(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTrialRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTrialRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -891,7 +891,7 @@ export class VizierServiceClient {
    * const [response] = await client.createTrial(request);
    */
   createTrial(
-    request: protos.google.cloud.aiplatform.v1beta1.ICreateTrialRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICreateTrialRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -934,7 +934,7 @@ export class VizierServiceClient {
     return this.innerApiCalls.createTrial(request, options, callback);
   }
   getTrial(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTrialRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTrialRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -984,7 +984,7 @@ export class VizierServiceClient {
    * const [response] = await client.getTrial(request);
    */
   getTrial(
-    request: protos.google.cloud.aiplatform.v1beta1.IGetTrialRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IGetTrialRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1027,7 +1027,7 @@ export class VizierServiceClient {
     return this.innerApiCalls.getTrial(request, options, callback);
   }
   addTrialMeasurement(
-    request: protos.google.cloud.aiplatform.v1beta1.IAddTrialMeasurementRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IAddTrialMeasurementRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1083,7 +1083,7 @@ export class VizierServiceClient {
    * const [response] = await client.addTrialMeasurement(request);
    */
   addTrialMeasurement(
-    request: protos.google.cloud.aiplatform.v1beta1.IAddTrialMeasurementRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IAddTrialMeasurementRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1129,7 +1129,7 @@ export class VizierServiceClient {
     return this.innerApiCalls.addTrialMeasurement(request, options, callback);
   }
   completeTrial(
-    request: protos.google.cloud.aiplatform.v1beta1.ICompleteTrialRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICompleteTrialRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1189,7 +1189,7 @@ export class VizierServiceClient {
    * const [response] = await client.completeTrial(request);
    */
   completeTrial(
-    request: protos.google.cloud.aiplatform.v1beta1.ICompleteTrialRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICompleteTrialRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1232,7 +1232,7 @@ export class VizierServiceClient {
     return this.innerApiCalls.completeTrial(request, options, callback);
   }
   deleteTrial(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTrialRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTrialRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1282,7 +1282,7 @@ export class VizierServiceClient {
    * const [response] = await client.deleteTrial(request);
    */
   deleteTrial(
-    request: protos.google.cloud.aiplatform.v1beta1.IDeleteTrialRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IDeleteTrialRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1325,7 +1325,7 @@ export class VizierServiceClient {
     return this.innerApiCalls.deleteTrial(request, options, callback);
   }
   stopTrial(
-    request: protos.google.cloud.aiplatform.v1beta1.IStopTrialRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IStopTrialRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1375,7 +1375,7 @@ export class VizierServiceClient {
    * const [response] = await client.stopTrial(request);
    */
   stopTrial(
-    request: protos.google.cloud.aiplatform.v1beta1.IStopTrialRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IStopTrialRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1418,7 +1418,7 @@ export class VizierServiceClient {
     return this.innerApiCalls.stopTrial(request, options, callback);
   }
   listOptimalTrials(
-    request: protos.google.cloud.aiplatform.v1beta1.IListOptimalTrialsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListOptimalTrialsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1472,7 +1472,7 @@ export class VizierServiceClient {
    * const [response] = await client.listOptimalTrials(request);
    */
   listOptimalTrials(
-    request: protos.google.cloud.aiplatform.v1beta1.IListOptimalTrialsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListOptimalTrialsRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1519,7 +1519,7 @@ export class VizierServiceClient {
   }
 
   suggestTrials(
-    request: protos.google.cloud.aiplatform.v1beta1.ISuggestTrialsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ISuggestTrialsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1588,7 +1588,7 @@ export class VizierServiceClient {
    * const [response] = await operation.promise();
    */
   suggestTrials(
-    request: protos.google.cloud.aiplatform.v1beta1.ISuggestTrialsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ISuggestTrialsRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1673,7 +1673,7 @@ export class VizierServiceClient {
     >;
   }
   checkTrialEarlyStoppingState(
-    request: protos.google.cloud.aiplatform.v1beta1.ICheckTrialEarlyStoppingStateRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICheckTrialEarlyStoppingStateRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1734,7 +1734,7 @@ export class VizierServiceClient {
    * const [response] = await operation.promise();
    */
   checkTrialEarlyStoppingState(
-    request: protos.google.cloud.aiplatform.v1beta1.ICheckTrialEarlyStoppingStateRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.ICheckTrialEarlyStoppingStateRequest,
     optionsOrCallback?:
       | CallOptions
       | Callback<
@@ -1823,7 +1823,7 @@ export class VizierServiceClient {
     >;
   }
   listStudies(
-    request: protos.google.cloud.aiplatform.v1beta1.IListStudiesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListStudiesRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -1881,7 +1881,7 @@ export class VizierServiceClient {
    *   for more details and examples.
    */
   listStudies(
-    request: protos.google.cloud.aiplatform.v1beta1.IListStudiesRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListStudiesRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<
@@ -2023,7 +2023,7 @@ export class VizierServiceClient {
     ) as AsyncIterable<protos.google.cloud.aiplatform.v1beta1.IStudy>;
   }
   listTrials(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTrialsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTrialsRequest,
     options?: CallOptions
   ): Promise<
     [
@@ -2081,7 +2081,7 @@ export class VizierServiceClient {
    *   for more details and examples.
    */
   listTrials(
-    request: protos.google.cloud.aiplatform.v1beta1.IListTrialsRequest,
+    request?: protos.google.cloud.aiplatform.v1beta1.IListTrialsRequest,
     optionsOrCallback?:
       | CallOptions
       | PaginationCallback<