diff --git a/packages/accessmanagement/NEXT_CHANGELOG.md b/packages/accessmanagement/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/accessmanagement/NEXT_CHANGELOG.md
+++ b/packages/accessmanagement/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/accessmanagement/src/v1/model.ts b/packages/accessmanagement/src/v1/model.ts
index 7357d490c..728241b74 100644
--- a/packages/accessmanagement/src/v1/model.ts
+++ b/packages/accessmanagement/src/v1/model.ts
@@ -36,7 +36,7 @@ export type PermissionLevel =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const RequestAuthzIdentity = {
-  REQUEST_AUTHZ_IDENTITY_UNSPECIFIED: 'REQUEST_AUTHZ_IDENTITY_UNSPECIFIED',
+  REQUEST_AUTHZ_IDENTITY_UNSPECIFIED: '',
   REQUEST_AUTHZ_IDENTITY_USER_CONTEXT: 'REQUEST_AUTHZ_IDENTITY_USER_CONTEXT',
   REQUEST_AUTHZ_IDENTITY_SERVICE_IDENTITY:
     'REQUEST_AUTHZ_IDENTITY_SERVICE_IDENTITY',
diff --git a/packages/apps/NEXT_CHANGELOG.md b/packages/apps/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/apps/NEXT_CHANGELOG.md
+++ b/packages/apps/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/apps/src/v1/model.ts b/packages/apps/src/v1/model.ts
index c705d9db5..4c385f80a 100644
--- a/packages/apps/src/v1/model.ts
+++ b/packages/apps/src/v1/model.ts
@@ -523,7 +523,7 @@ export type ErrorCode =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SpaceUpdateState = {
-  SPACE_UPDATE_STATE_UNSPECIFIED: 'SPACE_UPDATE_STATE_UNSPECIFIED',
+  SPACE_UPDATE_STATE_UNSPECIFIED: '',
   NOT_UPDATED: 'NOT_UPDATED',
   IN_PROGRESS: 'IN_PROGRESS',
   SUCCEEDED: 'SUCCEEDED',
@@ -535,7 +535,7 @@ export type SpaceUpdateState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AppDeployment_Mode = {
-  MODE_UNSPECIFIED: 'MODE_UNSPECIFIED',
+  MODE_UNSPECIFIED: '',
   SNAPSHOT: 'SNAPSHOT',
   AUTO_SYNC: 'AUTO_SYNC',
 } as const;
@@ -546,7 +546,7 @@ export type AppDeployment_Mode =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AppDeployment_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   SUCCEEDED: 'SUCCEEDED',
   FAILED: 'FAILED',
   IN_PROGRESS: 'IN_PROGRESS',
@@ -766,7 +766,7 @@ export type AppResourceUcSecurable_UcSecurableType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AppUpdate_UpdateStatus_UpdateState = {
-  UPDATE_STATE_UNSPECIFIED: 'UPDATE_STATE_UNSPECIFIED',
+  UPDATE_STATE_UNSPECIFIED: '',
   NOT_UPDATED: 'NOT_UPDATED',
   IN_PROGRESS: 'IN_PROGRESS',
   SUCCEEDED: 'SUCCEEDED',
@@ -779,7 +779,7 @@ export type AppUpdate_UpdateStatus_UpdateState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ApplicationStatus_ApplicationState = {
-  APPLICATION_STATE_UNSPECIFIED: 'APPLICATION_STATE_UNSPECIFIED',
+  APPLICATION_STATE_UNSPECIFIED: '',
   DEPLOYING: 'DEPLOYING',
   RUNNING: 'RUNNING',
   CRASHED: 'CRASHED',
@@ -792,7 +792,7 @@ export type ApplicationStatus_ApplicationState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ComputeStatus_ComputeState = {
-  COMPUTE_STATE_UNSPECIFIED: 'COMPUTE_STATE_UNSPECIFIED',
+  COMPUTE_STATE_UNSPECIFIED: '',
   ERROR: 'ERROR',
   DELETING: 'DELETING',
   STARTING: 'STARTING',
@@ -808,7 +808,7 @@ export type ComputeStatus_ComputeState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SpaceStatus_SpaceState = {
-  SPACE_STATE_UNSPECIFIED: 'SPACE_STATE_UNSPECIFIED',
+  SPACE_STATE_UNSPECIFIED: '',
   SPACE_CREATING: 'SPACE_CREATING',
   SPACE_ACTIVE: 'SPACE_ACTIVE',
   SPACE_ERROR: 'SPACE_ERROR',
diff --git a/packages/budgetpolicy/NEXT_CHANGELOG.md b/packages/budgetpolicy/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/budgetpolicy/NEXT_CHANGELOG.md
+++ b/packages/budgetpolicy/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/budgetpolicy/src/v1/model.ts b/packages/budgetpolicy/src/v1/model.ts
index 9ce4408aa..1d93f5d15 100644
--- a/packages/budgetpolicy/src/v1/model.ts
+++ b/packages/budgetpolicy/src/v1/model.ts
@@ -5,7 +5,7 @@ import {z} from 'zod';
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SortSpec_Field = {
   /** If unspecified, the server will decide the default field to sort on. */
-  FIELD_UNSPECIFIED: 'FIELD_UNSPECIFIED',
+  FIELD_UNSPECIFIED: '',
   /** Sort by policy name. */
   POLICY_NAME: 'POLICY_NAME',
 } as const;
diff --git a/packages/cleanrooms/NEXT_CHANGELOG.md b/packages/cleanrooms/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/cleanrooms/NEXT_CHANGELOG.md
+++ b/packages/cleanrooms/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/cleanrooms/src/v1/model.ts b/packages/cleanrooms/src/v1/model.ts
index 3c7a4e2c9..4bd05b58a 100644
--- a/packages/cleanrooms/src/v1/model.ts
+++ b/packages/cleanrooms/src/v1/model.ts
@@ -8,7 +8,7 @@ import {z} from 'zod';
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomTaskRunLifeCycleState = {
-  RUN_LIFE_CYCLE_STATE_UNSPECIFIED: 'RUN_LIFE_CYCLE_STATE_UNSPECIFIED',
+  RUN_LIFE_CYCLE_STATE_UNSPECIFIED: '',
   PENDING: 'PENDING',
   RUNNING: 'RUNNING',
   TERMINATING: 'TERMINATING',
@@ -29,7 +29,7 @@ export type CleanRoomTaskRunLifeCycleState =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomTaskRunResultState = {
-  RUN_RESULT_STATE_UNSPECIFIED: 'RUN_RESULT_STATE_UNSPECIFIED',
+  RUN_RESULT_STATE_UNSPECIFIED: '',
   SUCCESS: 'SUCCESS',
   FAILED: 'FAILED',
   TIMEDOUT: 'TIMEDOUT',
@@ -50,7 +50,7 @@ export type CleanRoomTaskRunResultState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomTaskType = {
-  CLEAN_ROOM_TASK_TYPE_UNSPECIFIED: 'CLEAN_ROOM_TASK_TYPE_UNSPECIFIED',
+  CLEAN_ROOM_TASK_TYPE_UNSPECIFIED: '',
   NOTEBOOK: 'NOTEBOOK',
   JAR: 'JAR',
 } as const;
@@ -93,7 +93,7 @@ export type ColumnTypeName =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ComplianceStandard = {
   /** Sentinel value, should not be used in prod */
-  COMPLIANCE_STANDARD_UNSPECIFIED: 'COMPLIANCE_STANDARD_UNSPECIFIED',
+  COMPLIANCE_STANDARD_UNSPECIFIED: '',
   /**
    * For customers who buy Enhanced Security Compliance (ESC) product
    * but don't belong to any standards.
@@ -154,7 +154,7 @@ export type CleanRoom_AccessRestricted =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoom_Status_Enum = {
-  ENUM_UNSPECIFIED: 'ENUM_UNSPECIFIED',
+  ENUM_UNSPECIFIED: '',
   ACTIVE: 'ACTIVE',
   PROVISIONING: 'PROVISIONING',
   DELETED: 'DELETED',
@@ -167,7 +167,7 @@ export type CleanRoom_Status_Enum =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomAsset_AssetType = {
-  ASSET_TYPE_UNSPECIFIED: 'ASSET_TYPE_UNSPECIFIED',
+  ASSET_TYPE_UNSPECIFIED: '',
   TABLE: 'TABLE',
   NOTEBOOK_FILE: 'NOTEBOOK_FILE',
   VOLUME: 'VOLUME',
@@ -182,7 +182,7 @@ export type CleanRoomAsset_AssetType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomAsset_Status_Enum = {
-  ENUM_UNSPECIFIED: 'ENUM_UNSPECIFIED',
+  ENUM_UNSPECIFIED: '',
   ACTIVE: 'ACTIVE',
   PERMISSION_DENIED: 'PERMISSION_DENIED',
   PENDING: 'PENDING',
@@ -194,7 +194,7 @@ export type CleanRoomAsset_Status_Enum =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomAutoApprovalRule_AuthorScope = {
-  AUTHOR_SCOPE_UNSPECIFIED: 'AUTHOR_SCOPE_UNSPECIFIED',
+  AUTHOR_SCOPE_UNSPECIFIED: '',
   ANY_AUTHOR: 'ANY_AUTHOR',
 } as const;
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Proto-style nested enum name.
@@ -204,8 +204,7 @@ export type CleanRoomAutoApprovalRule_AuthorScope =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomJarAnalysisReview_JarAnalysisReviewState = {
-  JAR_ANALYSIS_REVIEW_STATE_UNSPECIFIED:
-    'JAR_ANALYSIS_REVIEW_STATE_UNSPECIFIED',
+  JAR_ANALYSIS_REVIEW_STATE_UNSPECIFIED: '',
   APPROVED: 'APPROVED',
   REJECTED: 'REJECTED',
   PENDING: 'PENDING',
@@ -217,8 +216,7 @@ export type CleanRoomJarAnalysisReview_JarAnalysisReviewState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomJarAnalysisReview_JarAnalysisReviewSubReason = {
-  JAR_ANALYSIS_REVIEW_SUB_REASON_UNSPECIFIED:
-    'JAR_ANALYSIS_REVIEW_SUB_REASON_UNSPECIFIED',
+  JAR_ANALYSIS_REVIEW_SUB_REASON_UNSPECIFIED: '',
   AUTO_APPROVED: 'AUTO_APPROVED',
 } as const;
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Proto-style nested enum name.
@@ -228,7 +226,7 @@ export type CleanRoomJarAnalysisReview_JarAnalysisReviewSubReason =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomNotebookReview_NotebookReviewState = {
-  NOTEBOOK_REVIEW_STATE_UNSPECIFIED: 'NOTEBOOK_REVIEW_STATE_UNSPECIFIED',
+  NOTEBOOK_REVIEW_STATE_UNSPECIFIED: '',
   APPROVED: 'APPROVED',
   REJECTED: 'REJECTED',
   PENDING: 'PENDING',
@@ -240,8 +238,7 @@ export type CleanRoomNotebookReview_NotebookReviewState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomNotebookReview_NotebookReviewSubReason = {
-  NOTEBOOK_REVIEW_SUB_REASON_UNSPECIFIED:
-    'NOTEBOOK_REVIEW_SUB_REASON_UNSPECIFIED',
+  NOTEBOOK_REVIEW_SUB_REASON_UNSPECIFIED: '',
   BACKFILLED: 'BACKFILLED',
   AUTO_APPROVED: 'AUTO_APPROVED',
 } as const;
@@ -252,7 +249,7 @@ export type CleanRoomNotebookReview_NotebookReviewSubReason =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomOutputCatalog_OutputCatalogStatus = {
-  OUTPUT_CATALOG_STATUS_UNSPECIFIED: 'OUTPUT_CATALOG_STATUS_UNSPECIFIED',
+  OUTPUT_CATALOG_STATUS_UNSPECIFIED: '',
   /** The clean room is not eligible for output catalog. */
   NOT_ELIGIBLE: 'NOT_ELIGIBLE',
   /** The output catalog of the clean room is not yet created. */
@@ -274,8 +271,7 @@ export type CleanRoomOutputCatalog_OutputCatalogStatus =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_InternetAccessPolicy_InternetDestination_InternetDestinationFilteringProtocol =
   {
-    INTERNET_DESTINATION_FILTERING_PROTOCOL_UNSPECIFIED:
-      'INTERNET_DESTINATION_FILTERING_PROTOCOL_UNSPECIFIED',
+    INTERNET_DESTINATION_FILTERING_PROTOCOL_UNSPECIFIED: '',
     TCP: 'TCP',
   } as const;
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Proto-style nested enum name.
@@ -287,8 +283,7 @@ export type EgressNetworkPolicy_InternetAccessPolicy_InternetDestination_Interne
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_InternetAccessPolicy_InternetDestination_InternetDestinationType =
   {
-    INTERNET_DESTINATION_TYPE_UNSPECIFIED:
-      'INTERNET_DESTINATION_TYPE_UNSPECIFIED',
+    INTERNET_DESTINATION_TYPE_UNSPECIFIED: '',
     FQDN: 'FQDN',
   } as const;
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Proto-style nested enum name.
@@ -300,7 +295,7 @@ export type EgressNetworkPolicy_InternetAccessPolicy_InternetDestination_Interne
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_InternetAccessPolicy_LogOnlyMode_LogOnlyModeType =
   {
-    LOG_ONLY_MODE_TYPE_UNSPECIFIED: 'LOG_ONLY_MODE_TYPE_UNSPECIFIED',
+    LOG_ONLY_MODE_TYPE_UNSPECIFIED: '',
     ALL_SERVICES: 'ALL_SERVICES',
     SELECTED_SERVICES: 'SELECTED_SERVICES',
   } as const;
@@ -314,7 +309,7 @@ export type EgressNetworkPolicy_InternetAccessPolicy_LogOnlyMode_LogOnlyModeType
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_InternetAccessPolicy_LogOnlyMode_WorkloadType =
   {
-    WORKLOAD_TYPE_UNSPECIFIED: 'WORKLOAD_TYPE_UNSPECIFIED',
+    WORKLOAD_TYPE_UNSPECIFIED: '',
     DBSQL: 'DBSQL',
     ML_SERVING: 'ML_SERVING',
   } as const;
@@ -332,7 +327,7 @@ export type EgressNetworkPolicy_InternetAccessPolicy_LogOnlyMode_WorkloadType =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_InternetAccessPolicy_RestrictionMode = {
-  RESTRICTION_MODE_UNSPECIFIED: 'RESTRICTION_MODE_UNSPECIFIED',
+  RESTRICTION_MODE_UNSPECIFIED: '',
   FULL_ACCESS: 'FULL_ACCESS',
   PRIVATE_ACCESS_ONLY: 'PRIVATE_ACCESS_ONLY',
   RESTRICTED_ACCESS: 'RESTRICTED_ACCESS',
@@ -345,8 +340,7 @@ export type EgressNetworkPolicy_InternetAccessPolicy_RestrictionMode =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_InternetAccessPolicy_StorageDestination_StorageDestinationType =
   {
-    STORAGE_DESTINATION_TYPE_UNSPECIFIED:
-      'STORAGE_DESTINATION_TYPE_UNSPECIFIED',
+    STORAGE_DESTINATION_TYPE_UNSPECIFIED: '',
     AWS_S3: 'AWS_S3',
     CLOUDFLARE_R2: 'CLOUDFLARE_R2',
     AZURE_STORAGE: 'AZURE_STORAGE',
diff --git a/packages/clusters/NEXT_CHANGELOG.md b/packages/clusters/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/clusters/NEXT_CHANGELOG.md
+++ b/packages/clusters/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/clusters/src/v2/model.ts b/packages/clusters/src/v2/model.ts
index a53ff1e8f..c49aa9441 100644
--- a/packages/clusters/src/v2/model.ts
+++ b/packages/clusters/src/v2/model.ts
@@ -68,7 +68,7 @@ export type CloudProviderNodeStatus =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ComputeKind = {
-  COMPUTE_KIND_UNSPECIFIED: 'COMPUTE_KIND_UNSPECIFIED',
+  COMPUTE_KIND_UNSPECIFIED: '',
   CLASSIC_PREVIEW: 'CLASSIC_PREVIEW',
 } as const;
 export type ComputeKind =
@@ -83,8 +83,7 @@ export type ComputeKind =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ConfidentialComputeType = {
-  CONFIDENTIAL_COMPUTE_TYPE_UNSPECIFIED:
-    'CONFIDENTIAL_COMPUTE_TYPE_UNSPECIFIED',
+  CONFIDENTIAL_COMPUTE_TYPE_UNSPECIFIED: '',
   CONFIDENTIAL_COMPUTE_TYPE_NONE: 'CONFIDENTIAL_COMPUTE_TYPE_NONE',
   SEV_SNP: 'SEV_SNP',
 } as const;
@@ -974,7 +973,7 @@ export type ClusterState_ClusterState =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EnforcePolicyComplianceForClusterRequest_EnforceMode = {
   /** Default value. This value is unused. */
-  ENFORCE_MODE_UNSPECIFIED: 'ENFORCE_MODE_UNSPECIFIED',
+  ENFORCE_MODE_UNSPECIFIED: '',
   /**
    * If the cluster is in the TERMINATED state, edit the cluster immediately.
    * If the cluster is in the RUNNING state, edit and restart the cluster.
@@ -997,7 +996,7 @@ export type EnforcePolicyComplianceForClusterRequest_EnforceMode =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EnforcePolicyComplianceForClusterResponse_EnforceResult = {
   /** Default value. This value is unused. */
-  ENFORCE_RESULT_UNSPECIFIED: 'ENFORCE_RESULT_UNSPECIFIED',
+  ENFORCE_RESULT_UNSPECIFIED: '',
   /** No changes were made to the cluster. */
   NO_CHANGES: 'NO_CHANGES',
   /** Changes were applied to the cluster. */
@@ -1044,7 +1043,7 @@ export type InitScriptExecutionDetails_InitScriptExecutionStatus =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PendingEnforcement_EnforcementStatus = {
   /** Default value. This value is unused. */
-  ENFORCEMENT_STATUS_UNSPECIFIED: 'ENFORCEMENT_STATUS_UNSPECIFIED',
+  ENFORCEMENT_STATUS_UNSPECIFIED: '',
   /**
    * The pending enforcement will be attempted on the next cluster terminate or
    * restart.
diff --git a/packages/commandexecution/NEXT_CHANGELOG.md b/packages/commandexecution/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/commandexecution/NEXT_CHANGELOG.md
+++ b/packages/commandexecution/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/commandexecution/src/v2/model.ts b/packages/commandexecution/src/v2/model.ts
index 6b8ae91d2..128c55502 100644
--- a/packages/commandexecution/src/v2/model.ts
+++ b/packages/commandexecution/src/v2/model.ts
@@ -20,7 +20,7 @@ const jsonObjectSchema: z.ZodType<JsonObject> = z.record(
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CommandStatus = {
-  COMMAND_STATUS_UNSPECIFIED: 'COMMAND_STATUS_UNSPECIFIED',
+  COMMAND_STATUS_UNSPECIFIED: '',
   COMMAND_CANCELLED: 'Cancelled',
   COMMAND_CANCELLING: 'Cancelling',
   COMMAND_ERROR: 'Error',
@@ -34,7 +34,7 @@ export type CommandStatus =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ContextStatus = {
-  CONTEXT_STATUS_UNSPECIFIED: 'CONTEXT_STATUS_UNSPECIFIED',
+  CONTEXT_STATUS_UNSPECIFIED: '',
   CONTEXT_RUNNING: 'Running',
   CONTEXT_PENDING: 'Pending',
   CONTEXT_ERROR: 'Error',
@@ -45,7 +45,7 @@ export type ContextStatus =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Language = {
-  LANGUAGE_UNSPECIFIED: 'LANGUAGE_UNSPECIFIED',
+  LANGUAGE_UNSPECIFIED: '',
   PYTHON: 'python',
   SCALA: 'scala',
   SQL: 'sql',
@@ -55,7 +55,7 @@ export type Language = (typeof Language)[keyof typeof Language] | (string & {});
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ResultType = {
-  RESULT_TYPE_UNSPECIFIED: 'RESULT_TYPE_UNSPECIFIED',
+  RESULT_TYPE_UNSPECIFIED: '',
   ERROR_RESULT: 'error',
   IMAGE_RESULT: 'image',
   IMAGES_RESULT: 'images',
diff --git a/packages/customllms/NEXT_CHANGELOG.md b/packages/customllms/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/customllms/NEXT_CHANGELOG.md
+++ b/packages/customllms/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/customllms/src/v1/model.ts b/packages/customllms/src/v1/model.ts
index ffac99e13..53a4ff5f7 100644
--- a/packages/customllms/src/v1/model.ts
+++ b/packages/customllms/src/v1/model.ts
@@ -8,7 +8,7 @@ import {z} from 'zod';
 /** States of Custom LLM optimization lifecycle. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   CREATED: 'CREATED',
   RUNNING: 'RUNNING',
   COMPLETED: 'COMPLETED',
diff --git a/packages/database/NEXT_CHANGELOG.md b/packages/database/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/database/NEXT_CHANGELOG.md
+++ b/packages/database/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/database/src/v1/model.ts b/packages/database/src/v1/model.ts
index bff146412..ea174339b 100644
--- a/packages/database/src/v1/model.ts
+++ b/packages/database/src/v1/model.ts
@@ -8,7 +8,7 @@ import {z} from 'zod';
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ProvisioningPhase = {
   /** The default phase. It should not be reported by any synced tables. */
-  PROVISIONING_PHASE_UNSPECIFIED: 'PROVISIONING_PHASE_UNSPECIFIED',
+  PROVISIONING_PHASE_UNSPECIFIED: '',
   /** Ingestion phase of the synced table. This is when the synced table is ingesting data from the delta table. */
   PROVISIONING_PHASE_MAIN: 'PROVISIONING_PHASE_MAIN',
   /** Index scan phase of the synced table. This is when the synced table is creating indexes on the ingested data. */
@@ -22,8 +22,7 @@ export type ProvisioningPhase =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SyncedTableSchedulingPolicy = {
-  SYNCED_TABLE_SCHEDULING_POLICY_UNSPECIFIED:
-    'SYNCED_TABLE_SCHEDULING_POLICY_UNSPECIFIED',
+  SYNCED_TABLE_SCHEDULING_POLICY_UNSPECIFIED: '',
   /**
    * Pipeline runs continuously after generating the initial data.
    * Requires the source table to have Change Data Feed (CDF) enabled.
@@ -49,7 +48,7 @@ export type SyncedTableSchedulingPolicy =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SyncedTableState = {
   /** The default state. It should not be reported by any synced tables. */
-  SYNCED_TABLE_STATE_UNSPECIFIED: 'SYNCED_TABLE_STATE_UNSPECIFIED',
+  SYNCED_TABLE_STATE_UNSPECIFIED: '',
   /**
    * The synced table has just been created and resources are being provisioned. This is also the
    * catch-all state if there is not a more suitable state to report for the synced table.
@@ -107,7 +106,7 @@ export type SyncedTableState =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const DatabaseInstance_State = {
   /** Default value, not used */
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   /** The instance is being brought online. */
   STARTING: 'STARTING',
   /** The instance is active and ready to use. */
@@ -129,7 +128,7 @@ export type DatabaseInstance_State =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const DatabaseInstanceRole_IdentityType = {
   /** Default value, not used */
-  IDENTITY_TYPE_UNSPECIFIED: 'IDENTITY_TYPE_UNSPECIFIED',
+  IDENTITY_TYPE_UNSPECIFIED: '',
   /** A role without a Databricks identity. */
   PG_ONLY: 'PG_ONLY',
   /** A user in a Databricks workspace. */
@@ -148,7 +147,7 @@ export type DatabaseInstanceRole_IdentityType =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const DatabaseInstanceRole_MembershipRole = {
   /** Indicates that the DatabaseInstanceRole is not a member of any standard, managed roles. */
-  MEMBERSHIP_ROLE_UNSPECIFIED: 'MEMBERSHIP_ROLE_UNSPECIFIED',
+  MEMBERSHIP_ROLE_UNSPECIFIED: '',
   /** Indicates membership in DATABRICKS_SUPERUSER, the highest set of privileges exposed to customers. */
   DATABRICKS_SUPERUSER: 'DATABRICKS_SUPERUSER',
 } as const;
@@ -159,7 +158,7 @@ export type DatabaseInstanceRole_MembershipRole =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ProvisioningInfo_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   PROVISIONING: 'PROVISIONING',
   ACTIVE: 'ACTIVE',
   FAILED: 'FAILED',
@@ -175,7 +174,7 @@ export type ProvisioningInfo_State =
 /** Might add WRITE in the future */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const RequestedClaims_PermissionSet = {
-  PERMISSION_SET_UNSPECIFIED: 'PERMISSION_SET_UNSPECIFIED',
+  PERMISSION_SET_UNSPECIFIED: '',
   READ_ONLY: 'READ_ONLY',
 } as const;
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Proto-style nested enum name.
@@ -187,7 +186,7 @@ export type RequestedClaims_PermissionSet =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SyncedTableSpec_PgSpecificType = {
   /** Default value. Indicates that no type override was selected. */
-  PG_SPECIFIC_TYPE_UNSPECIFIED: 'PG_SPECIFIC_TYPE_UNSPECIFIED',
+  PG_SPECIFIC_TYPE_UNSPECIFIED: '',
   /** Maps the column to the pgvector vector type. */
   PG_SPECIFIC_TYPE_VECTOR: 'PG_SPECIFIC_TYPE_VECTOR',
 } as const;
diff --git a/packages/dataclassification/NEXT_CHANGELOG.md b/packages/dataclassification/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/dataclassification/NEXT_CHANGELOG.md
+++ b/packages/dataclassification/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/dataclassification/src/v1/model.ts b/packages/dataclassification/src/v1/model.ts
index 9d51f0c9b..f1d07af74 100644
--- a/packages/dataclassification/src/v1/model.ts
+++ b/packages/dataclassification/src/v1/model.ts
@@ -7,7 +7,7 @@ import {z} from 'zod';
 /** Auto-tagging mode. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AutoTaggingConfig_AutoTaggingMode = {
-  AUTO_TAGGING_MODE_UNSPECIFIED: 'AUTO_TAGGING_MODE_UNSPECIFIED',
+  AUTO_TAGGING_MODE_UNSPECIFIED: '',
   AUTO_TAGGING_DISABLED: 'AUTO_TAGGING_DISABLED',
   AUTO_TAGGING_ENABLED: 'AUTO_TAGGING_ENABLED',
 } as const;
diff --git a/packages/dataquality/NEXT_CHANGELOG.md b/packages/dataquality/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/dataquality/NEXT_CHANGELOG.md
+++ b/packages/dataquality/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/dataquality/src/v1/model.ts b/packages/dataquality/src/v1/model.ts
index 0b3f27125..a74812cd2 100644
--- a/packages/dataquality/src/v1/model.ts
+++ b/packages/dataquality/src/v1/model.ts
@@ -7,7 +7,7 @@ import {z} from 'zod';
 /** The granularity for aggregating data into time windows based on their timestamp. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AggregationGranularity = {
-  AGGREGATION_GRANULARITY_UNSPECIFIED: 'AGGREGATION_GRANULARITY_UNSPECIFIED',
+  AGGREGATION_GRANULARITY_UNSPECIFIED: '',
   /** 5 minutes. */
   AGGREGATION_GRANULARITY_5_MINUTES: 'AGGREGATION_GRANULARITY_5_MINUTES',
   /** 30 minutes. */
@@ -36,8 +36,7 @@ export type AggregationGranularity =
 /** The data quality monitoring workflow cron schedule pause status. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CronSchedulePauseStatus = {
-  CRON_SCHEDULE_PAUSE_STATUS_UNSPECIFIED:
-    'CRON_SCHEDULE_PAUSE_STATUS_UNSPECIFIED',
+  CRON_SCHEDULE_PAUSE_STATUS_UNSPECIFIED: '',
   /** The cron schedule is not paused. */
   CRON_SCHEDULE_PAUSE_STATUS_UNPAUSED: 'CRON_SCHEDULE_PAUSE_STATUS_UNPAUSED',
   /** The cron schedule is paused. */
@@ -50,8 +49,7 @@ export type CronSchedulePauseStatus =
 /** The custom metric type. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const DataProfilingCustomMetricType = {
-  DATA_PROFILING_CUSTOM_METRIC_TYPE_UNSPECIFIED:
-    'DATA_PROFILING_CUSTOM_METRIC_TYPE_UNSPECIFIED',
+  DATA_PROFILING_CUSTOM_METRIC_TYPE_UNSPECIFIED: '',
   /** Only depend on the existing columns in the table. */
   DATA_PROFILING_CUSTOM_METRIC_TYPE_AGGREGATE:
     'DATA_PROFILING_CUSTOM_METRIC_TYPE_AGGREGATE',
@@ -69,7 +67,7 @@ export type DataProfilingCustomMetricType =
 /** The status of the data profiling monitor. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const DataProfilingStatus = {
-  DATA_PROFILING_STATUS_UNSPECIFIED: 'DATA_PROFILING_STATUS_UNSPECIFIED',
+  DATA_PROFILING_STATUS_UNSPECIFIED: '',
   DATA_PROFILING_STATUS_ACTIVE: 'DATA_PROFILING_STATUS_ACTIVE',
   DATA_PROFILING_STATUS_PENDING: 'DATA_PROFILING_STATUS_PENDING',
   DATA_PROFILING_STATUS_DELETE_PENDING: 'DATA_PROFILING_STATUS_DELETE_PENDING',
@@ -83,7 +81,7 @@ export type DataProfilingStatus =
 /** Inference problem type the model aims to solve. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const InferenceProblemType = {
-  INFERENCE_PROBLEM_TYPE_UNSPECIFIED: 'INFERENCE_PROBLEM_TYPE_UNSPECIFIED',
+  INFERENCE_PROBLEM_TYPE_UNSPECIFIED: '',
   /** Classification inference problem. */
   INFERENCE_PROBLEM_TYPE_CLASSIFICATION:
     'INFERENCE_PROBLEM_TYPE_CLASSIFICATION',
diff --git a/packages/disasterrecovery/NEXT_CHANGELOG.md b/packages/disasterrecovery/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/disasterrecovery/NEXT_CHANGELOG.md
+++ b/packages/disasterrecovery/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/disasterrecovery/src/v1/model.ts b/packages/disasterrecovery/src/v1/model.ts
index a08c94cec..7052caafd 100644
--- a/packages/disasterrecovery/src/v1/model.ts
+++ b/packages/disasterrecovery/src/v1/model.ts
@@ -8,7 +8,7 @@ import {z} from 'zod';
 /** The type of failover to perform. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const FailoverFailoverGroupRequest_FailoverType = {
-  FAILOVER_TYPE_UNSPECIFIED: 'FAILOVER_TYPE_UNSPECIFIED',
+  FAILOVER_TYPE_UNSPECIFIED: '',
   FORCED: 'FORCED',
 } as const;
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Proto-style nested enum name.
@@ -19,7 +19,7 @@ export type FailoverFailoverGroupRequest_FailoverType =
 /** The aggregate state of a FailoverGroup. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const FailoverGroup_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   /** FailoverGroup is being created, setup in progress. */
   CREATING: 'CREATING',
   /** FailoverGroup creation failed. */
diff --git a/packages/environments/NEXT_CHANGELOG.md b/packages/environments/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/environments/NEXT_CHANGELOG.md
+++ b/packages/environments/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/environments/src/v1/model.ts b/packages/environments/src/v1/model.ts
index 0a9b14c62..ea980cea1 100644
--- a/packages/environments/src/v1/model.ts
+++ b/packages/environments/src/v1/model.ts
@@ -8,7 +8,7 @@ import {z} from 'zod';
 /** If changed, also update estore/namespaces/defaultbaseenvironments/latest.proto */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const BaseEnvironmentType = {
-  BASE_ENVIRONMENT_TYPE_UNSPECIFIED: 'BASE_ENVIRONMENT_TYPE_UNSPECIFIED',
+  BASE_ENVIRONMENT_TYPE_UNSPECIFIED: '',
   CPU: 'CPU',
   GPU: 'GPU',
 } as const;
@@ -525,7 +525,7 @@ export type ErrorCode =
 /** Status of the environment materialization. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const WorkspaceBaseEnvironmentCache_Status = {
-  STATUS_UNSPECIFIED: 'STATUS_UNSPECIFIED',
+  STATUS_UNSPECIFIED: '',
   /** Materialized environment creation is pending. */
   PENDING: 'PENDING',
   /** Materialized environment has been successfully created. */
diff --git a/packages/experiments/NEXT_CHANGELOG.md b/packages/experiments/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/experiments/NEXT_CHANGELOG.md
+++ b/packages/experiments/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/experiments/src/v1/model.ts b/packages/experiments/src/v1/model.ts
index 51eec46b3..d3794206e 100644
--- a/packages/experiments/src/v1/model.ts
+++ b/packages/experiments/src/v1/model.ts
@@ -8,7 +8,7 @@ import {z} from 'zod';
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const LoggedModelStatus = {
-  LOGGED_MODEL_STATUS_UNSPECIFIED: 'LOGGED_MODEL_STATUS_UNSPECIFIED',
+  LOGGED_MODEL_STATUS_UNSPECIFIED: '',
   /**
    * The LoggedModel has been created, but the LoggedModel files are not
    * completely uploaded.
diff --git a/packages/features/NEXT_CHANGELOG.md b/packages/features/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/features/NEXT_CHANGELOG.md
+++ b/packages/features/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/features/src/v1/model.ts b/packages/features/src/v1/model.ts
index 6467ade58..bbaaae716 100644
--- a/packages/features/src/v1/model.ts
+++ b/packages/features/src/v1/model.ts
@@ -11,7 +11,7 @@ import {z} from 'zod';
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ScalarDataType = {
-  SCALAR_DATA_TYPE_UNSPECIFIED: 'SCALAR_DATA_TYPE_UNSPECIFIED',
+  SCALAR_DATA_TYPE_UNSPECIFIED: '',
   INTEGER: 'INTEGER',
   FLOAT: 'FLOAT',
   BOOLEAN: 'BOOLEAN',
@@ -31,7 +31,7 @@ export type ScalarDataType =
 /** Deprecated: Use the function-specific messages in AggregationFunction.function_type oneof instead. Kept for backwards compatibility. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Function_FunctionType = {
-  FUNCTION_TYPE_UNSPECIFIED: 'FUNCTION_TYPE_UNSPECIFIED',
+  FUNCTION_TYPE_UNSPECIFIED: '',
   AVG: 'AVG',
   COUNT: 'COUNT',
   SUM: 'SUM',
@@ -54,7 +54,7 @@ export type Function_FunctionType =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const MaterializedFeature_PipelineScheduleState = {
   /** Default value, not used. */
-  PIPELINE_SCHEDULE_STATE_UNSPECIFIED: 'PIPELINE_SCHEDULE_STATE_UNSPECIFIED',
+  PIPELINE_SCHEDULE_STATE_UNSPECIFIED: '',
   /** Pipeline was configured to run once then stop. */
   SNAPSHOT: 'SNAPSHOT',
   /** Pipeline is actively running and computing features. */
@@ -70,7 +70,7 @@ export type MaterializedFeature_PipelineScheduleState =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const StreamingMode_StreamingModeType = {
   /** Default value, not used. */
-  STREAMING_MODE_TYPE_UNSPECIFIED: 'STREAMING_MODE_TYPE_UNSPECIFIED',
+  STREAMING_MODE_TYPE_UNSPECIFIED: '',
   /**
    * Real-time mode. Ultra-low-latency trigger intended for operational workloads
    * that need responses in milliseconds or sub-second latency.
diff --git a/packages/featurestore/NEXT_CHANGELOG.md b/packages/featurestore/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/featurestore/NEXT_CHANGELOG.md
+++ b/packages/featurestore/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/featurestore/src/v1/model.ts b/packages/featurestore/src/v1/model.ts
index f2bf0fdf7..85828f20f 100644
--- a/packages/featurestore/src/v1/model.ts
+++ b/packages/featurestore/src/v1/model.ts
@@ -8,7 +8,7 @@ import {z} from 'zod';
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const OnlineStore_State = {
   /** Default value, not used */
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   /** The online store is being brought online. */
   STARTING: 'STARTING',
   /** The online store is active and ready to use. */
@@ -29,7 +29,7 @@ export type OnlineStore_State =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PublishSpec_PublishMode = {
-  PUBLISH_MODE_UNSPECIFIED: 'PUBLISH_MODE_UNSPECIFIED',
+  PUBLISH_MODE_UNSPECIFIED: '',
   /**
    * Pipeline runs continuously after syncing the initial data.
    * Requires the source table to have Change Data Feed (CDF) enabled.
diff --git a/packages/genie/NEXT_CHANGELOG.md b/packages/genie/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/genie/NEXT_CHANGELOG.md
+++ b/packages/genie/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/genie/src/v1/model.ts b/packages/genie/src/v1/model.ts
index d3771e8b8..7948cb0e5 100644
--- a/packages/genie/src/v1/model.ts
+++ b/packages/genie/src/v1/model.ts
@@ -541,7 +541,7 @@ export type ErrorCode =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EvaluationStatusType = {
-  EVALUATION_STATUS_TYPE_UNSPECIFIED: 'EVALUATION_STATUS_TYPE_UNSPECIFIED',
+  EVALUATION_STATUS_TYPE_UNSPECIFIED: '',
   RUNNING: 'RUNNING',
   DONE: 'DONE',
   NOT_STARTED: 'NOT_STARTED',
@@ -555,7 +555,7 @@ export type EvaluationStatusType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Format = {
-  FORMAT_UNSPECIFIED: 'FORMAT_UNSPECIFIED',
+  FORMAT_UNSPECIFIED: '',
   JSON_ARRAY: 'JSON_ARRAY',
   ARROW_STREAM: 'ARROW_STREAM',
   CSV: 'CSV',
@@ -564,7 +564,7 @@ export type Format = (typeof Format)[keyof typeof Format] | (string & {});
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const GenieEvalAssessment = {
-  GENIE_EVAL_ASSESSMENT_UNSPECIFIED: 'GENIE_EVAL_ASSESSMENT_UNSPECIFIED',
+  GENIE_EVAL_ASSESSMENT_UNSPECIFIED: '',
   GOOD: 'GOOD',
   BAD: 'BAD',
   NEEDS_REVIEW: 'NEEDS_REVIEW',
@@ -575,7 +575,7 @@ export type GenieEvalAssessment =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const GenieEvalResponseType = {
-  GENIE_EVAL_RESPONSE_TYPE_UNSPECIFIED: 'GENIE_EVAL_RESPONSE_TYPE_UNSPECIFIED',
+  GENIE_EVAL_RESPONSE_TYPE_UNSPECIFIED: '',
   TEXT: 'TEXT',
   SQL: 'SQL',
 } as const;
@@ -586,7 +586,7 @@ export type GenieEvalResponseType =
 /** Feedback rating for Genie messages */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const GenieFeedbackRating = {
-  GENIE_FEEDBACK_RATING_UNSPECIFIED: 'GENIE_FEEDBACK_RATING_UNSPECIFIED',
+  GENIE_FEEDBACK_RATING_UNSPECIFIED: '',
   POSITIVE: 'POSITIVE',
   NEGATIVE: 'NEGATIVE',
   NONE: 'NONE',
@@ -614,7 +614,7 @@ export type NullValue =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ScoreReason = {
-  SCORE_REASON_UNSPECIFIED: 'SCORE_REASON_UNSPECIFIED',
+  SCORE_REASON_UNSPECIFIED: '',
   EMPTY_RESULT: 'EMPTY_RESULT',
   RESULT_MISSING_ROWS: 'RESULT_MISSING_ROWS',
   RESULT_EXTRA_ROWS: 'RESULT_EXTRA_ROWS',
@@ -657,7 +657,7 @@ export type ScoreReason =
 /** Purpose/intent of a text attachment */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const TextAttachmentPurpose = {
-  TEXT_ATTACHMENT_PURPOSE_UNSPECIFIED: 'TEXT_ATTACHMENT_PURPOSE_UNSPECIFIED',
+  TEXT_ATTACHMENT_PURPOSE_UNSPECIFIED: '',
   FOLLOW_UP_QUESTION: 'FOLLOW_UP_QUESTION',
 } as const;
 export type TextAttachmentPurpose =
@@ -678,7 +678,7 @@ export type TextAttachmentPurpose =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ThoughtType = {
-  THOUGHT_TYPE_UNSPECIFIED: 'THOUGHT_TYPE_UNSPECIFIED',
+  THOUGHT_TYPE_UNSPECIFIED: '',
   /** A high-level description of how the question was interpreted. */
   THOUGHT_TYPE_DESCRIPTION: 'THOUGHT_TYPE_DESCRIPTION',
   /** How ambiguous parts of the question were resolved. */
@@ -696,7 +696,7 @@ export type ThoughtType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const MessageError_Type = {
-  TYPE_UNSPECIFIED: 'TYPE_UNSPECIFIED',
+  TYPE_UNSPECIFIED: '',
   UNEXPECTED_REPLY_PROCESS_EXCEPTION: 'UNEXPECTED_REPLY_PROCESS_EXCEPTION',
   GENERIC_CHAT_COMPLETION_EXCEPTION: 'GENERIC_CHAT_COMPLETION_EXCEPTION',
   /** TokenCounter estimates were off and OpenAi responds with an error due to the token limit. */
@@ -826,7 +826,7 @@ export type MessageStatus_MessageStatus =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const StatementStatus_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   PENDING: 'PENDING',
   RUNNING: 'RUNNING',
   SUCCEEDED: 'SUCCEEDED',
diff --git a/packages/jobs/NEXT_CHANGELOG.md b/packages/jobs/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/jobs/NEXT_CHANGELOG.md
+++ b/packages/jobs/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/jobs/src/v2/model.ts b/packages/jobs/src/v2/model.ts
index 3165678bf..47cac16bf 100644
--- a/packages/jobs/src/v2/model.ts
+++ b/packages/jobs/src/v2/model.ts
@@ -65,7 +65,7 @@ export type AzureAvailability =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ComputeKind = {
-  COMPUTE_KIND_UNSPECIFIED: 'COMPUTE_KIND_UNSPECIFIED',
+  COMPUTE_KIND_UNSPECIFIED: '',
   CLASSIC_PREVIEW: 'CLASSIC_PREVIEW',
 } as const;
 export type ComputeKind =
@@ -80,8 +80,7 @@ export type ComputeKind =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ConfidentialComputeType = {
-  CONFIDENTIAL_COMPUTE_TYPE_UNSPECIFIED:
-    'CONFIDENTIAL_COMPUTE_TYPE_UNSPECIFIED',
+  CONFIDENTIAL_COMPUTE_TYPE_UNSPECIFIED: '',
   CONFIDENTIAL_COMPUTE_TYPE_NONE: 'CONFIDENTIAL_COMPUTE_TYPE_NONE',
   SEV_SNP: 'SEV_SNP',
 } as const;
@@ -154,7 +153,7 @@ export type DataSecurityMode =
 /** Response enumeration from calling the dbt platform API, for inclusion in output */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const DbtPlatformRunStatus = {
-  DBT_PLATFORM_RUN_STATUS_UNSPECIFIED: 'DBT_PLATFORM_RUN_STATUS_UNSPECIFIED',
+  DBT_PLATFORM_RUN_STATUS_UNSPECIFIED: '',
   QUEUED: 'QUEUED',
   STARTING: 'STARTING',
   RUNNING: 'RUNNING',
@@ -344,8 +343,7 @@ export type Source = (typeof Source)[keyof typeof Source] | (string & {});
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SqlConditionTriggerMode = {
-  SQL_CONDITION_TRIGGER_MODE_UNSPECIFIED:
-    'SQL_CONDITION_TRIGGER_MODE_UNSPECIFIED',
+  SQL_CONDITION_TRIGGER_MODE_UNSPECIFIED: '',
   QUERY_RETURNS_ROWS: 'QUERY_RETURNS_ROWS',
   RESULT_VALUE_CHANGES: 'RESULT_VALUE_CHANGES',
 } as const;
@@ -471,7 +469,7 @@ export type AccessControlRequest_JobPermission =
 /** Same alert evaluation state as in redash-v2/api/proto/alertsv2/alerts.proto */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AlertEvaluationState_AlertEvaluationState = {
-  ALERT_EVALUATION_STATE_UNSPECIFIED: 'ALERT_EVALUATION_STATE_UNSPECIFIED',
+  ALERT_EVALUATION_STATE_UNSPECIFIED: '',
   UNKNOWN: 'UNKNOWN',
   TRIGGERED: 'TRIGGERED',
   OK: 'OK',
@@ -488,7 +486,7 @@ export type AlertEvaluationState_AlertEvaluationState =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomTaskRunLifeCycleState_CleanRoomTaskRunLifeCycleState = {
-  RUN_LIFE_CYCLE_STATE_UNSPECIFIED: 'RUN_LIFE_CYCLE_STATE_UNSPECIFIED',
+  RUN_LIFE_CYCLE_STATE_UNSPECIFIED: '',
   PENDING: 'PENDING',
   RUNNING: 'RUNNING',
   TERMINATING: 'TERMINATING',
@@ -510,7 +508,7 @@ export type CleanRoomTaskRunLifeCycleState_CleanRoomTaskRunLifeCycleState =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CleanRoomTaskRunResultState_CleanRoomTaskRunResultState = {
-  RUN_RESULT_STATE_UNSPECIFIED: 'RUN_RESULT_STATE_UNSPECIFIED',
+  RUN_RESULT_STATE_UNSPECIFIED: '',
   SUCCESS: 'SUCCESS',
   FAILED: 'FAILED',
   TIMEDOUT: 'TIMEDOUT',
@@ -603,7 +601,7 @@ export type JobSource_DirtyState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ModelTriggerConfiguration_ModelTriggerCondition = {
-  CONDITION_UNSPECIFIED: 'CONDITION_UNSPECIFIED',
+  CONDITION_UNSPECIFIED: '',
   MODEL_CREATED: 'MODEL_CREATED',
   MODEL_VERSION_READY: 'MODEL_VERSION_READY',
   MODEL_ALIAS_SET: 'MODEL_ALIAS_SET',
@@ -620,7 +618,7 @@ export type ModelTriggerConfiguration_ModelTriggerCondition =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PerformanceTarget_PerformanceTarget = {
-  PERFORMANCE_TARGET_UNSPECIFIED: 'PERFORMANCE_TARGET_UNSPECIFIED',
+  PERFORMANCE_TARGET_UNSPECIFIED: '',
   PERFORMANCE_OPTIMIZED: 'PERFORMANCE_OPTIMIZED',
   STANDARD: 'STANDARD',
 } as const;
@@ -631,7 +629,7 @@ export type PerformanceTarget_PerformanceTarget =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PeriodicTriggerConfiguration_TimeUnit = {
-  TIME_UNIT_UNSPECIFIED: 'TIME_UNIT_UNSPECIFIED',
+  TIME_UNIT_UNSPECIFIED: '',
   HOURS: 'HOURS',
   DAYS: 'DAYS',
   WEEKS: 'WEEKS',
diff --git a/packages/knowledgeassistants/NEXT_CHANGELOG.md b/packages/knowledgeassistants/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/knowledgeassistants/NEXT_CHANGELOG.md
+++ b/packages/knowledgeassistants/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/knowledgeassistants/src/v1/model.ts b/packages/knowledgeassistants/src/v1/model.ts
index 837573691..3df207660 100644
--- a/packages/knowledgeassistants/src/v1/model.ts
+++ b/packages/knowledgeassistants/src/v1/model.ts
@@ -7,7 +7,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const KnowledgeAssistant_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   CREATING: 'CREATING',
   ACTIVE: 'ACTIVE',
   FAILED: 'FAILED',
@@ -19,7 +19,7 @@ export type KnowledgeAssistant_State =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const KnowledgeSource_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   UPDATING: 'UPDATING',
   UPDATED: 'UPDATED',
   FAILED_UPDATE: 'FAILED_UPDATE',
diff --git a/packages/marketplaces/NEXT_CHANGELOG.md b/packages/marketplaces/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/marketplaces/NEXT_CHANGELOG.md
+++ b/packages/marketplaces/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/marketplaces/src/v1/model.ts b/packages/marketplaces/src/v1/model.ts
index bb33435ef..1cc605934 100644
--- a/packages/marketplaces/src/v1/model.ts
+++ b/packages/marketplaces/src/v1/model.ts
@@ -4,7 +4,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AssetType = {
-  ASSET_TYPE_UNSPECIFIED: 'ASSET_TYPE_UNSPECIFIED',
+  ASSET_TYPE_UNSPECIFIED: '',
   ASSET_TYPE_GIT_REPO: 'ASSET_TYPE_GIT_REPO',
   ASSET_TYPE_DATA_TABLE: 'ASSET_TYPE_DATA_TABLE',
   ASSET_TYPE_MODEL: 'ASSET_TYPE_MODEL',
@@ -156,7 +156,7 @@ export type ListingStatus =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ListingTagType = {
-  LISTING_TAG_TYPE_UNSPECIFIED: 'LISTING_TAG_TYPE_UNSPECIFIED',
+  LISTING_TAG_TYPE_UNSPECIFIED: '',
   LISTING_TAG_TYPE_LANGUAGE: 'LISTING_TAG_TYPE_LANGUAGE',
   LISTING_TAG_TYPE_TASK: 'LISTING_TAG_TYPE_TASK',
 } as const;
diff --git a/packages/modelserving/NEXT_CHANGELOG.md b/packages/modelserving/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/modelserving/NEXT_CHANGELOG.md
+++ b/packages/modelserving/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/modelserving/src/v1/model.ts b/packages/modelserving/src/v1/model.ts
index 264deddbe..b0fbddaf7 100644
--- a/packages/modelserving/src/v1/model.ts
+++ b/packages/modelserving/src/v1/model.ts
@@ -4,7 +4,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Behavior = {
-  BEHAVIOR_UNSPECIFIED: 'BEHAVIOR_UNSPECIFIED',
+  BEHAVIOR_UNSPECIFIED: '',
   NONE: 'NONE',
   BLOCK: 'BLOCK',
   MASK: 'MASK',
@@ -37,7 +37,7 @@ export type ServingEndpointDetailedPermissionLevel =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ExternalFunctionRequest_HttpMethod = {
-  HTTP_METHOD_UNSPECIFIED: 'HTTP_METHOD_UNSPECIFIED',
+  HTTP_METHOD_UNSPECIFIED: '',
   GET: 'GET',
   POST: 'POST',
   PUT: 'PUT',
@@ -51,7 +51,7 @@ export type ExternalFunctionRequest_HttpMethod =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const InferenceEndpointState_ConfigUpdateState = {
-  CONFIG_UPDATE_STATE_UNSPECIFIED: 'CONFIG_UPDATE_STATE_UNSPECIFIED',
+  CONFIG_UPDATE_STATE_UNSPECIFIED: '',
   NOT_UPDATING: 'NOT_UPDATING',
   IN_PROGRESS: 'IN_PROGRESS',
   UPDATE_FAILED: 'UPDATE_FAILED',
@@ -64,7 +64,7 @@ export type InferenceEndpointState_ConfigUpdateState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const InferenceEndpointState_ReadyState = {
-  READY_STATE_UNSPECIFIED: 'READY_STATE_UNSPECIFIED',
+  READY_STATE_UNSPECIFIED: '',
   READY: 'READY',
   NOT_READY: 'NOT_READY',
 } as const;
diff --git a/packages/modelservingquery/NEXT_CHANGELOG.md b/packages/modelservingquery/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/modelservingquery/NEXT_CHANGELOG.md
+++ b/packages/modelservingquery/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/modelservingquery/src/v1/model.ts b/packages/modelservingquery/src/v1/model.ts
index b9c6df169..93821bc83 100644
--- a/packages/modelservingquery/src/v1/model.ts
+++ b/packages/modelservingquery/src/v1/model.ts
@@ -17,7 +17,7 @@ const jsonValueSchema: z.ZodType<JsonValue> = z.lazy(() =>
 /** The role of the message. One of [system, user, assistant]. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ChatMessageRole = {
-  CHAT_MESSAGE_ROLE_UNSPECIFIED: 'CHAT_MESSAGE_ROLE_UNSPECIFIED',
+  CHAT_MESSAGE_ROLE_UNSPECIFIED: '',
   SYSTEM: 'system',
   USER: 'user',
   ASSISTANT: 'assistant',
@@ -29,8 +29,7 @@ export type ChatMessageRole =
 /** This will always be 'embedding'. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EmbeddingsV1ResponseEmbeddingElementObject = {
-  EMBEDDINGS_V1_RESPONSE_EMBEDDING_ELEMENT_OBJECT_UNSPECIFIED:
-    'EMBEDDINGS_V1_RESPONSE_EMBEDDING_ELEMENT_OBJECT_UNSPECIFIED',
+  EMBEDDINGS_V1_RESPONSE_EMBEDDING_ELEMENT_OBJECT_UNSPECIFIED: '',
   EMBEDDING: 'embedding',
 } as const;
 export type EmbeddingsV1ResponseEmbeddingElementObject =
@@ -43,8 +42,7 @@ export type EmbeddingsV1ResponseEmbeddingElementObject =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const QueryEndpointResponseObject = {
-  QUERY_ENDPOINT_RESPONSE_OBJECT_UNSPECIFIED:
-    'QUERY_ENDPOINT_RESPONSE_OBJECT_UNSPECIFIED',
+  QUERY_ENDPOINT_RESPONSE_OBJECT_UNSPECIFIED: '',
   TEXT_COMPLETION: 'text_completion',
   CHAT_COMPLETION: 'chat.completion',
   LIST: 'list',
diff --git a/packages/networking/NEXT_CHANGELOG.md b/packages/networking/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/networking/NEXT_CHANGELOG.md
+++ b/packages/networking/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/networking/src/v1/model.ts b/packages/networking/src/v1/model.ts
index 4d382cff4..e9ac5a65e 100644
--- a/packages/networking/src/v1/model.ts
+++ b/packages/networking/src/v1/model.ts
@@ -12,7 +12,7 @@ import {z} from 'zod';
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressResourceType = {
-  EGRESS_RESOURCE_TYPE_UNSPECIFIED: 'EGRESS_RESOURCE_TYPE_UNSPECIFIED',
+  EGRESS_RESOURCE_TYPE_UNSPECIFIED: '',
   AZURE_BLOB_STORAGE: 'AZURE_BLOB_STORAGE',
 } as const;
 export type EgressResourceType =
@@ -105,8 +105,7 @@ export type AccountIpAccessListType_IpAccessListType =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_NetworkAccessPolicy_InternetDestination_InternetDestinationType =
   {
-    INTERNET_DESTINATION_TYPE_UNSPECIFIED:
-      'INTERNET_DESTINATION_TYPE_UNSPECIFIED',
+    INTERNET_DESTINATION_TYPE_UNSPECIFIED: '',
     /** This is defined as `FQDN` in settings-policy/api/proto/messages.proto. Translation is done in accounts-lake-net-manager/src/util/NetworkPolicySettingUtil.scala. */
     DNS_NAME: 'DNS_NAME',
   } as const;
@@ -120,8 +119,7 @@ export type EgressNetworkPolicy_NetworkAccessPolicy_InternetDestination_Internet
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_NetworkAccessPolicy_PolicyEnforcement_DryRunModeProductFilter =
   {
-    DRY_RUN_MODE_PRODUCT_FILTER_UNSPECIFIED:
-      'DRY_RUN_MODE_PRODUCT_FILTER_UNSPECIFIED',
+    DRY_RUN_MODE_PRODUCT_FILTER_UNSPECIFIED: '',
     /** SQL Warehouse product */
     DBSQL: 'DBSQL',
     /** Machine Learning serving product */
@@ -136,7 +134,7 @@ export type EgressNetworkPolicy_NetworkAccessPolicy_PolicyEnforcement_DryRunMode
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_NetworkAccessPolicy_PolicyEnforcement_EnforcementMode =
   {
-    ENFORCEMENT_MODE_UNSPECIFIED: 'ENFORCEMENT_MODE_UNSPECIFIED',
+    ENFORCEMENT_MODE_UNSPECIFIED: '',
     /** Blocks traffic that violates network policy. This is the default mode. */
     ENFORCED: 'ENFORCED',
     /** Logs violations without blocking traffic. Useful for testing policies before enforcement. */
@@ -156,7 +154,7 @@ export type EgressNetworkPolicy_NetworkAccessPolicy_PolicyEnforcement_Enforcemen
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_NetworkAccessPolicy_RestrictionMode = {
-  RESTRICTION_MODE_UNSPECIFIED: 'RESTRICTION_MODE_UNSPECIFIED',
+  RESTRICTION_MODE_UNSPECIFIED: '',
   FULL_ACCESS: 'FULL_ACCESS',
   RESTRICTED_ACCESS: 'RESTRICTED_ACCESS',
 } as const;
@@ -168,8 +166,7 @@ export type EgressNetworkPolicy_NetworkAccessPolicy_RestrictionMode =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EgressNetworkPolicy_NetworkAccessPolicy_StorageDestination_StorageDestinationType =
   {
-    STORAGE_DESTINATION_TYPE_UNSPECIFIED:
-      'STORAGE_DESTINATION_TYPE_UNSPECIFIED',
+    STORAGE_DESTINATION_TYPE_UNSPECIFIED: '',
     /**
      * AWS_S3 can be used both for direct AWS S3 access and for cross-cloud access from Azure and GCP
      * When used in an Azure/GCP context, this indicates cross-cloud access from Azure/GCP to the specified S3 bucket
@@ -213,7 +210,7 @@ export type IngressNetworkPolicy_ApiScopeQualifier =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const IngressNetworkPolicy_Authentication_IdentityType = {
-  IDENTITY_TYPE_UNSPECIFIED: 'IDENTITY_TYPE_UNSPECIFIED',
+  IDENTITY_TYPE_UNSPECIFIED: '',
   IDENTITY_TYPE_ALL_USERS: 'IDENTITY_TYPE_ALL_USERS',
   IDENTITY_TYPE_ALL_SERVICE_PRINCIPALS: 'IDENTITY_TYPE_ALL_SERVICE_PRINCIPALS',
   IDENTITY_TYPE_SELECTED_IDENTITIES: 'IDENTITY_TYPE_SELECTED_IDENTITIES',
@@ -225,7 +222,7 @@ export type IngressNetworkPolicy_Authentication_IdentityType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const IngressNetworkPolicy_AuthenticationIdentity_PrincipalType = {
-  PRINCIPAL_TYPE_UNSPECIFIED: 'PRINCIPAL_TYPE_UNSPECIFIED',
+  PRINCIPAL_TYPE_UNSPECIFIED: '',
   PRINCIPAL_TYPE_USER: 'PRINCIPAL_TYPE_USER',
   PRINCIPAL_TYPE_SERVICE_PRINCIPAL: 'PRINCIPAL_TYPE_SERVICE_PRINCIPAL',
 } as const;
@@ -281,8 +278,7 @@ export type IngressNetworkPolicy_PublicAccess_RestrictionMode =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const NccPrivateEndpointRule_PrivateLinkConnectionState = {
-  PRIVATE_LINK_CONNECTION_STATE_UNSPECIFIED:
-    'PRIVATE_LINK_CONNECTION_STATE_UNSPECIFIED',
+  PRIVATE_LINK_CONNECTION_STATE_UNSPECIFIED: '',
   /** The endpoint has been approved and is ready to use in your serverless compute resources. */
   ESTABLISHED: 'ESTABLISHED',
   /** Connection was rejected by the private link resource owner. */
@@ -309,8 +305,7 @@ export type NccPrivateEndpointRule_PrivateLinkConnectionState =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const NetworkConnectivityConfigAwsPrivateEndpointRule_PrivateLinkConnectionState =
   {
-    PRIVATE_LINK_CONNECTION_STATE_UNSPECIFIED:
-      'PRIVATE_LINK_CONNECTION_STATE_UNSPECIFIED',
+    PRIVATE_LINK_CONNECTION_STATE_UNSPECIFIED: '',
     /** The endpoint has been approved and is ready to use in your serverless compute resources. */
     ESTABLISHED: 'ESTABLISHED',
     /** Connection was rejected by the private link resource owner. */
@@ -338,8 +333,7 @@ export type NetworkConnectivityConfigAwsPrivateEndpointRule_PrivateLinkConnectio
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const NetworkConnectivityConfigAzurePrivateEndpointRule_PrivateLinkConnectionState =
   {
-    PRIVATE_LINK_CONNECTION_STATE_UNSPECIFIED:
-      'PRIVATE_LINK_CONNECTION_STATE_UNSPECIFIED',
+    PRIVATE_LINK_CONNECTION_STATE_UNSPECIFIED: '',
     /** The endpoint has been created and pending approval. */
     INIT: 'INIT',
     /** The endpoint has been approved and is ready to use in your serverless compute resources. */
diff --git a/packages/pipelines/NEXT_CHANGELOG.md b/packages/pipelines/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/pipelines/NEXT_CHANGELOG.md
+++ b/packages/pipelines/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/pipelines/src/v2/model.ts b/packages/pipelines/src/v2/model.ts
index 07d5fee63..0b4078228 100644
--- a/packages/pipelines/src/v2/model.ts
+++ b/packages/pipelines/src/v2/model.ts
@@ -19,7 +19,7 @@ export type CloneMode =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ConnectorType = {
-  CONNECTOR_TYPE_UNSPECIFIED: 'CONNECTOR_TYPE_UNSPECIFIED',
+  CONNECTOR_TYPE_UNSPECIFIED: '',
   /**
    * If connector_type = CDC and ingestion_gateway_id is provided then we use Ingestion Gateway pipeline with
    * Cdc Managed Ingestion Pipeline for ingestion, if connector_type = CDC and connection_name is provided
@@ -38,7 +38,7 @@ export type ConnectorType =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const DayOfWeek = {
-  DAY_OF_WEEK_UNSPECIFIED: 'DAY_OF_WEEK_UNSPECIFIED',
+  DAY_OF_WEEK_UNSPECIFIED: '',
   MONDAY: 'MONDAY',
   TUESDAY: 'TUESDAY',
   WEDNESDAY: 'WEDNESDAY',
@@ -78,7 +78,7 @@ export type EventLevel =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const IngestionSourceType = {
-  INGESTION_SOURCE_TYPE_UNSPECIFIED: 'INGESTION_SOURCE_TYPE_UNSPECIFIED',
+  INGESTION_SOURCE_TYPE_UNSPECIFIED: '',
   MYSQL: 'MYSQL',
   POSTGRESQL: 'POSTGRESQL',
   SQLSERVER: 'SQLSERVER',
@@ -118,7 +118,7 @@ export type MaturityLevel =
 /** Attachment behavior mode for Outlook ingestion */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const OutlookAttachmentMode = {
-  OUTLOOK_ATTACHMENT_MODE_UNSPECIFIED: 'OUTLOOK_ATTACHMENT_MODE_UNSPECIFIED',
+  OUTLOOK_ATTACHMENT_MODE_UNSPECIFIED: '',
   /** Ingest all attachments (both inline and non-inline) */
   ALL: 'ALL',
   /** Ingest only non-inline attachments (recommended to avoid corporate signature images) */
@@ -135,7 +135,7 @@ export type OutlookAttachmentMode =
 /** Body format for Outlook email content */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const OutlookBodyFormat = {
-  OUTLOOK_BODY_FORMAT_UNSPECIFIED: 'OUTLOOK_BODY_FORMAT_UNSPECIFIED',
+  OUTLOOK_BODY_FORMAT_UNSPECIFIED: '',
   TEXT_HTML: 'TEXT_HTML',
   TEXT_PLAIN: 'TEXT_PLAIN',
 } as const;
@@ -216,7 +216,7 @@ export type PipelinesGcpAvailability =
 /** Enum representing the publishing mode of a pipeline. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PublishingMode = {
-  PUBLISHING_MODE_UNSPECIFIED: 'PUBLISHING_MODE_UNSPECIFIED',
+  PUBLISHING_MODE_UNSPECIFIED: '',
   LEGACY_PUBLISHING_MODE: 'LEGACY_PUBLISHING_MODE',
   DEFAULT_PUBLISHING_MODE: 'DEFAULT_PUBLISHING_MODE',
 } as const;
@@ -278,7 +278,7 @@ export type UpdateState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const FileIngestionOptions_FileFormat = {
-  FILE_FORMAT_UNSPECIFIED: 'FILE_FORMAT_UNSPECIFIED',
+  FILE_FORMAT_UNSPECIFIED: '',
   BINARYFILE: 'BINARYFILE',
   JSON: 'JSON',
   CSV: 'CSV',
@@ -296,7 +296,7 @@ export type FileIngestionOptions_FileFormat =
 /** Based on https://docs.databricks.com/aws/en/ingestion/cloud-object-storage/auto-loader/schema#how-does-auto-loader-schema-evolution-work */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const FileIngestionOptions_SchemaEvolutionMode = {
-  SCHEMA_EVOLUTION_MODE_UNSPECIFIED: 'SCHEMA_EVOLUTION_MODE_UNSPECIFIED',
+  SCHEMA_EVOLUTION_MODE_UNSPECIFIED: '',
   ADD_NEW_COLUMNS_WITH_TYPE_WIDENING: 'ADD_NEW_COLUMNS_WITH_TYPE_WIDENING',
   ADD_NEW_COLUMNS: 'ADD_NEW_COLUMNS',
   RESCUE: 'RESCUE',
@@ -310,7 +310,7 @@ export type FileIngestionOptions_SchemaEvolutionMode =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const GoogleDriveOptions_GoogleDriveEntityType = {
-  GOOGLE_DRIVE_ENTITY_TYPE_UNSPECIFIED: 'GOOGLE_DRIVE_ENTITY_TYPE_UNSPECIFIED',
+  GOOGLE_DRIVE_ENTITY_TYPE_UNSPECIFIED: '',
   FILE: 'FILE',
   FILE_METADATA: 'FILE_METADATA',
   PERMISSION: 'PERMISSION',
@@ -350,7 +350,7 @@ export type PipelineState_PipelineState =
 /** The SCD type to use to ingest the table. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ScdType_ScdType = {
-  SCD_TYPE_UNSPECIFIED: 'SCD_TYPE_UNSPECIFIED',
+  SCD_TYPE_UNSPECIFIED: '',
   SCD_TYPE_1: 'SCD_TYPE_1',
   SCD_TYPE_2: 'SCD_TYPE_2',
   /**
@@ -366,7 +366,7 @@ export type ScdType_ScdType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SharepointOptions_SharepointEntityType = {
-  SHAREPOINT_ENTITY_TYPE_UNSPECIFIED: 'SHAREPOINT_ENTITY_TYPE_UNSPECIFIED',
+  SHAREPOINT_ENTITY_TYPE_UNSPECIFIED: '',
   FILE: 'FILE',
   FILE_METADATA: 'FILE_METADATA',
   PERMISSION: 'PERMISSION',
@@ -380,7 +380,7 @@ export type SharepointOptions_SharepointEntityType =
 /** Data level for TikTok Ads report aggregation. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const TikTokAdsOptions_TikTokDataLevel = {
-  TIK_TOK_DATA_LEVEL_UNSPECIFIED: 'TIK_TOK_DATA_LEVEL_UNSPECIFIED',
+  TIK_TOK_DATA_LEVEL_UNSPECIFIED: '',
   AUCTION_ADVERTISER: 'AUCTION_ADVERTISER',
   AUCTION_CAMPAIGN: 'AUCTION_CAMPAIGN',
   AUCTION_ADGROUP: 'AUCTION_ADGROUP',
@@ -394,7 +394,7 @@ export type TikTokAdsOptions_TikTokDataLevel =
 /** Report type for TikTok Ads API. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const TikTokAdsOptions_TikTokReportType = {
-  TIK_TOK_REPORT_TYPE_UNSPECIFIED: 'TIK_TOK_REPORT_TYPE_UNSPECIFIED',
+  TIK_TOK_REPORT_TYPE_UNSPECIFIED: '',
   BASIC: 'BASIC',
   AUDIENCE: 'AUDIENCE',
   PLAYABLE_AD: 'PLAYABLE_AD',
@@ -409,7 +409,7 @@ export type TikTokAdsOptions_TikTokReportType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Transformer_Format = {
-  FORMAT_UNSPECIFIED: 'FORMAT_UNSPECIFIED',
+  FORMAT_UNSPECIFIED: '',
   STRING: 'STRING',
   JSON: 'JSON',
 } as const;
diff --git a/packages/postgres/NEXT_CHANGELOG.md b/packages/postgres/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/postgres/NEXT_CHANGELOG.md
+++ b/packages/postgres/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/postgres/src/v1/model.ts b/packages/postgres/src/v1/model.ts
index 395b61b99..bd9608705 100644
--- a/packages/postgres/src/v1/model.ts
+++ b/packages/postgres/src/v1/model.ts
@@ -9,7 +9,7 @@ import {z} from 'zod';
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CdfState = {
   /** Default value. Returned when the replication state is unknown or not set. */
-  CDF_STATE_UNSPECIFIED: 'CDF_STATE_UNSPECIFIED',
+  CDF_STATE_UNSPECIFIED: '',
   /**
    * Taking the initial snapshot: the table's existing rows are being written
    * to the Delta table.
@@ -35,7 +35,7 @@ export type CdfState = (typeof CdfState)[keyof typeof CdfState] | (string & {});
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EndpointType = {
   /** Default value, not used */
-  ENDPOINT_TYPE_UNSPECIFIED: 'ENDPOINT_TYPE_UNSPECIFIED',
+  ENDPOINT_TYPE_UNSPECIFIED: '',
   ENDPOINT_TYPE_READ_WRITE: 'ENDPOINT_TYPE_READ_WRITE',
   ENDPOINT_TYPE_READ_ONLY: 'ENDPOINT_TYPE_READ_ONLY',
 } as const;
@@ -558,7 +558,7 @@ export type ErrorCode =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const OpenApiMode = {
   /** Unspecified; the server applies its default mode. */
-  OPEN_API_MODE_UNSPECIFIED: 'OPEN_API_MODE_UNSPECIFIED',
+  OPEN_API_MODE_UNSPECIFIED: '',
   /** Generate OpenAPI output ignoring the privileges of the requesting role. */
   OPEN_API_MODE_IGNORE_PRIVILEGES: 'OPEN_API_MODE_IGNORE_PRIVILEGES',
   /** Disable the OpenAPI documentation endpoint entirely. */
@@ -572,7 +572,7 @@ export type OpenApiMode =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ProvisioningPhase = {
   /** The default phase. It should not be reported by any synced tables. */
-  PROVISIONING_PHASE_UNSPECIFIED: 'PROVISIONING_PHASE_UNSPECIFIED',
+  PROVISIONING_PHASE_UNSPECIFIED: '',
   /** Ingestion phase of the synced table. This is when the synced table is ingesting data from the delta table. */
   PROVISIONING_PHASE_MAIN: 'PROVISIONING_PHASE_MAIN',
   /** Index scan phase of the synced table. This is when the synced table is creating indexes on the ingested data. */
@@ -588,7 +588,7 @@ export type ProvisioningPhase =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SyncedTableState = {
   /** The default state. It should not be reported by any synced tables. */
-  SYNCED_TABLE_STATE_UNSPECIFIED: 'SYNCED_TABLE_STATE_UNSPECIFIED',
+  SYNCED_TABLE_STATE_UNSPECIFIED: '',
   /**
    * The synced table has just been created and resources are being provisioned. This is also the
    * catch-all state if there is not a more suitable state to report for the synced table.
@@ -647,7 +647,7 @@ export type SyncedTableState =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const BranchStatus_State = {
   /** Default value, not used. */
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   /** The branch is being created but is not yet available for querying. */
   INIT: 'INIT',
   /** The branch is being imported and is not yet available for querying. */
@@ -670,7 +670,7 @@ export type BranchStatus_State =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EndpointStatus_State = {
   /** Default value, not used */
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   INIT: 'INIT',
   ACTIVE: 'ACTIVE',
   IDLE: 'IDLE',
@@ -683,7 +683,7 @@ export type EndpointStatus_State =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ProvisioningInfo_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   PROVISIONING: 'PROVISIONING',
   ACTIVE: 'ACTIVE',
   FAILED: 'FAILED',
@@ -698,7 +698,7 @@ export type ProvisioningInfo_State =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const RequestedClaims_PermissionSet = {
-  PERMISSION_SET_UNSPECIFIED: 'PERMISSION_SET_UNSPECIFIED',
+  PERMISSION_SET_UNSPECIFIED: '',
   READ_ONLY: 'READ_ONLY',
 } as const;
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Proto-style nested enum name.
@@ -709,7 +709,7 @@ export type RequestedClaims_PermissionSet =
 /** How the role is authenticated when connecting to Postgres. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Role_AuthMethod = {
-  AUTH_METHOD_UNSPECIFIED: 'AUTH_METHOD_UNSPECIFIED',
+  AUTH_METHOD_UNSPECIFIED: '',
   /** NO_LOGIN means this role cannot be used for interactive access */
   NO_LOGIN: 'NO_LOGIN',
   /** PG_PASSWORD_SCRAM_SHA_256 is a password-based authentication */
@@ -732,7 +732,7 @@ export type Role_AuthMethod =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Role_IdentityType = {
   /** Default value, not used */
-  IDENTITY_TYPE_UNSPECIFIED: 'IDENTITY_TYPE_UNSPECIFIED',
+  IDENTITY_TYPE_UNSPECIFIED: '',
   /** A user in a <Databricks> workspace. */
   USER: 'USER',
   /** A service principal in a <Databricks> workspace. */
@@ -749,7 +749,7 @@ export type Role_IdentityType =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Role_MembershipRole = {
   /** Indicates that the DatabaseInstanceRole is not a member of any standard, managed roles. */
-  MEMBERSHIP_ROLE_UNSPECIFIED: 'MEMBERSHIP_ROLE_UNSPECIFIED',
+  MEMBERSHIP_ROLE_UNSPECIFIED: '',
   /** Indicates membership in DATABRICKS_SUPERUSER, the highest set of privileges exposed to customers. */
   DATABRICKS_SUPERUSER: 'DATABRICKS_SUPERUSER',
 } as const;
@@ -762,7 +762,7 @@ export type Role_MembershipRole =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SyncedTable_SyncedTableSpec_PgSpecificType = {
   /** Default value. Indicates that no type override was selected. */
-  PG_SPECIFIC_TYPE_UNSPECIFIED: 'PG_SPECIFIC_TYPE_UNSPECIFIED',
+  PG_SPECIFIC_TYPE_UNSPECIFIED: '',
   /** Maps the column to the pgvector vector type. */
   PG_SPECIFIC_TYPE_VECTOR: 'PG_SPECIFIC_TYPE_VECTOR',
 } as const;
@@ -774,8 +774,7 @@ export type SyncedTable_SyncedTableSpec_PgSpecificType =
 /** Scheduling policy of the synced table's underlying pipeline. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SyncedTable_SyncedTableSpec_SyncedTableSchedulingPolicy = {
-  SYNCED_TABLE_SCHEDULING_POLICY_UNSPECIFIED:
-    'SYNCED_TABLE_SCHEDULING_POLICY_UNSPECIFIED',
+  SYNCED_TABLE_SCHEDULING_POLICY_UNSPECIFIED: '',
   /**
    * Pipeline runs continuously after generating the initial data.
    * Requires the source table to have Change Data Feed (CDF) enabled.
diff --git a/packages/queryhistory/NEXT_CHANGELOG.md b/packages/queryhistory/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/queryhistory/NEXT_CHANGELOG.md
+++ b/packages/queryhistory/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/queryhistory/src/v1/model.ts b/packages/queryhistory/src/v1/model.ts
index 246bb444b..376c55594 100644
--- a/packages/queryhistory/src/v1/model.ts
+++ b/packages/queryhistory/src/v1/model.ts
@@ -4,7 +4,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ChannelName = {
-  CHANNEL_NAME_UNSPECIFIED: 'CHANNEL_NAME_UNSPECIFIED',
+  CHANNEL_NAME_UNSPECIFIED: '',
   CHANNEL_NAME_PREVIEW: 'CHANNEL_NAME_PREVIEW',
   CHANNEL_NAME_CURRENT: 'CHANNEL_NAME_CURRENT',
   CHANNEL_NAME_PREVIOUS: 'CHANNEL_NAME_PREVIOUS',
diff --git a/packages/scim/NEXT_CHANGELOG.md b/packages/scim/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/scim/NEXT_CHANGELOG.md
+++ b/packages/scim/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/scim/src/v1/model.ts b/packages/scim/src/v1/model.ts
index 3d5b235d9..eb74231bf 100644
--- a/packages/scim/src/v1/model.ts
+++ b/packages/scim/src/v1/model.ts
@@ -16,7 +16,7 @@ const jsonValueSchema: z.ZodType<JsonValue> = z.lazy(() =>
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const GetSortOrder = {
-  GET_SORT_ORDER_UNSPECIFIED: 'GET_SORT_ORDER_UNSPECIFIED',
+  GET_SORT_ORDER_UNSPECIFIED: '',
   ASCENDING: 'ascending',
   DESCENDING: 'descending',
 } as const;
@@ -26,7 +26,7 @@ export type GetSortOrder =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const GroupSchema = {
-  GROUP_SCHEMA_UNSPECIFIED: 'GROUP_SCHEMA_UNSPECIFIED',
+  GROUP_SCHEMA_UNSPECIFIED: '',
   URN_IETF_PARAMS_SCIM_SCHEMAS_CORE_2_0_GROUP:
     'urn:ietf:params:scim:schemas:core:2.0:Group',
 } as const;
@@ -36,7 +36,7 @@ export type GroupSchema =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ListResponseSchema = {
-  LIST_RESPONSE_SCHEMA_UNSPECIFIED: 'LIST_RESPONSE_SCHEMA_UNSPECIFIED',
+  LIST_RESPONSE_SCHEMA_UNSPECIFIED: '',
   URN_IETF_PARAMS_SCIM_API_MESSAGES_2_0_LIST_RESPONSE:
     'urn:ietf:params:scim:api:messages:2.0:ListResponse',
 } as const;
@@ -47,7 +47,7 @@ export type ListResponseSchema =
 /** Type of patch operation. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PatchOp = {
-  PATCH_OP_UNSPECIFIED: 'PATCH_OP_UNSPECIFIED',
+  PATCH_OP_UNSPECIFIED: '',
   ADD: 'add',
   REMOVE: 'remove',
   REPLACE: 'replace',
@@ -56,7 +56,7 @@ export type PatchOp = (typeof PatchOp)[keyof typeof PatchOp] | (string & {});
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PatchSchema = {
-  PATCH_SCHEMA_UNSPECIFIED: 'PATCH_SCHEMA_UNSPECIFIED',
+  PATCH_SCHEMA_UNSPECIFIED: '',
   URN_IETF_PARAMS_SCIM_API_MESSAGES_2_0_PATCH_OP:
     'urn:ietf:params:scim:api:messages:2.0:PatchOp',
 } as const;
@@ -66,7 +66,7 @@ export type PatchSchema =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ServicePrincipalSchema = {
-  SERVICE_PRINCIPAL_SCHEMA_UNSPECIFIED: 'SERVICE_PRINCIPAL_SCHEMA_UNSPECIFIED',
+  SERVICE_PRINCIPAL_SCHEMA_UNSPECIFIED: '',
   URN_IETF_PARAMS_SCIM_SCHEMAS_CORE_2_0_SERVICE_PRINCIPAL:
     'urn:ietf:params:scim:schemas:core:2.0:ServicePrincipal',
 } as const;
@@ -76,7 +76,7 @@ export type ServicePrincipalSchema =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const UserSchema = {
-  USER_SCHEMA_UNSPECIFIED: 'USER_SCHEMA_UNSPECIFIED',
+  USER_SCHEMA_UNSPECIFIED: '',
   URN_IETF_PARAMS_SCIM_SCHEMAS_CORE_2_0_USER:
     'urn:ietf:params:scim:schemas:core:2.0:User',
   URN_IETF_PARAMS_SCIM_SCHEMAS_EXTENSION_WORKSPACE_2_0_USER:
@@ -88,7 +88,7 @@ export type UserSchema =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AccountGetSortOrder_GetSortOrder = {
-  GET_SORT_ORDER_UNSPECIFIED: 'GET_SORT_ORDER_UNSPECIFIED',
+  GET_SORT_ORDER_UNSPECIFIED: '',
   ASCENDING: 'ascending',
   DESCENDING: 'descending',
 } as const;
@@ -99,7 +99,7 @@ export type AccountGetSortOrder_GetSortOrder =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AccountListSort_Order = {
-  ORDER_UNSPECIFIED: 'ORDER_UNSPECIFIED',
+  ORDER_UNSPECIFIED: '',
   ASCENDING: 'ascending',
   DESCENDING: 'descending',
 } as const;
@@ -111,7 +111,7 @@ export type AccountListSort_Order =
 /** Type of patch operation. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AccountPatchOp_PatchOp = {
-  PATCH_OP_UNSPECIFIED: 'PATCH_OP_UNSPECIFIED',
+  PATCH_OP_UNSPECIFIED: '',
   ADD: 'add',
   REMOVE: 'remove',
   REPLACE: 'replace',
@@ -123,7 +123,7 @@ export type AccountPatchOp_PatchOp =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AccountPatchSchema_PatchSchema = {
-  PATCH_SCHEMA_UNSPECIFIED: 'PATCH_SCHEMA_UNSPECIFIED',
+  PATCH_SCHEMA_UNSPECIFIED: '',
   URN_IETF_PARAMS_SCIM_API_MESSAGES_2_0_PATCH_OP:
     'urn:ietf:params:scim:api:messages:2.0:PatchOp',
 } as const;
@@ -134,7 +134,7 @@ export type AccountPatchSchema_PatchSchema =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ListSort_Order = {
-  ORDER_UNSPECIFIED: 'ORDER_UNSPECIFIED',
+  ORDER_UNSPECIFIED: '',
   ASCENDING: 'ascending',
   DESCENDING: 'descending',
 } as const;
@@ -146,7 +146,7 @@ export type ListSort_Order =
 /** Permission level */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PasswordPermission_Level = {
-  LEVEL_UNSPECIFIED: 'LEVEL_UNSPECIFIED',
+  LEVEL_UNSPECIFIED: '',
   CAN_USE: 'CAN_USE',
 } as const;
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Proto-style nested enum name.
diff --git a/packages/settings/NEXT_CHANGELOG.md b/packages/settings/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/settings/NEXT_CHANGELOG.md
+++ b/packages/settings/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/settings/src/v2/model.ts b/packages/settings/src/v2/model.ts
index 26ca8b2e9..f7c933dd2 100644
--- a/packages/settings/src/v2/model.ts
+++ b/packages/settings/src/v2/model.ts
@@ -11,7 +11,7 @@ import {z} from 'zod';
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PreviewPhase = {
   /** Default value. Indicates the preview phase is unknown or the setting is not a feature preview. */
-  PREVIEW_PHASE_UNSPECIFIED: 'PREVIEW_PHASE_UNSPECIFIED',
+  PREVIEW_PHASE_UNSPECIFIED: '',
   /** The feature is in private preview, available only to specifically enrolled customers. */
   PRIVATE_PREVIEW: 'PRIVATE_PREVIEW',
   /**
@@ -32,7 +32,7 @@ export type PreviewPhase =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AibiDashboardEmbeddingAccessPolicy_AccessPolicyType = {
-  ACCESS_POLICY_TYPE_UNSPECIFIED: 'ACCESS_POLICY_TYPE_UNSPECIFIED',
+  ACCESS_POLICY_TYPE_UNSPECIFIED: '',
   ALLOW_ALL_DOMAINS: 'ALLOW_ALL_DOMAINS',
   ALLOW_APPROVED_DOMAINS: 'ALLOW_APPROVED_DOMAINS',
   DENY_ALL_DOMAINS: 'DENY_ALL_DOMAINS',
@@ -44,7 +44,7 @@ export type AibiDashboardEmbeddingAccessPolicy_AccessPolicyType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ClusterAutoRestartMessage_MaintenanceWindow_DayOfWeek = {
-  DAY_OF_WEEK_UNSPECIFIED: 'DAY_OF_WEEK_UNSPECIFIED',
+  DAY_OF_WEEK_UNSPECIFIED: '',
   MONDAY: 'MONDAY',
   TUESDAY: 'TUESDAY',
   WEDNESDAY: 'WEDNESDAY',
@@ -60,7 +60,7 @@ export type ClusterAutoRestartMessage_MaintenanceWindow_DayOfWeek =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ClusterAutoRestartMessage_MaintenanceWindow_WeekDayFrequency = {
-  WEEK_DAY_FREQUENCY_UNSPECIFIED: 'WEEK_DAY_FREQUENCY_UNSPECIFIED',
+  WEEK_DAY_FREQUENCY_UNSPECIFIED: '',
   FIRST_OF_MONTH: 'FIRST_OF_MONTH',
   SECOND_OF_MONTH: 'SECOND_OF_MONTH',
   THIRD_OF_MONTH: 'THIRD_OF_MONTH',
@@ -76,7 +76,7 @@ export type ClusterAutoRestartMessage_MaintenanceWindow_WeekDayFrequency =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const CollaborationPlatformConnectivityMessage_Connectivity = {
-  CONNECTIVITY_UNSPECIFIED: 'CONNECTIVITY_UNSPECIFIED',
+  CONNECTIVITY_UNSPECIFIED: '',
   ALLOW_ALL: 'ALLOW_ALL',
   ALLOW_TEAMS: 'ALLOW_TEAMS',
   ALLOW_SLACK: 'ALLOW_SLACK',
@@ -93,8 +93,7 @@ export type CollaborationPlatformConnectivityMessage_Connectivity =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PersonalComputeMessage_PersonalComputeMessageEnum = {
-  PERSONAL_COMPUTE_MESSAGE_ENUM_UNSPECIFIED:
-    'PERSONAL_COMPUTE_MESSAGE_ENUM_UNSPECIFIED',
+  PERSONAL_COMPUTE_MESSAGE_ENUM_UNSPECIFIED: '',
   ON: 'ON',
   DELEGATE: 'DELEGATE',
 } as const;
@@ -106,7 +105,7 @@ export type PersonalComputeMessage_PersonalComputeMessageEnum =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const RestrictWorkspaceAdminsMessage_Status = {
   /** Default value for proto enum */
-  STATUS_UNSPECIFIED: 'STATUS_UNSPECIFIED',
+  STATUS_UNSPECIFIED: '',
   /**
    * Default value for existing workspaces
    * Allows WS admins to create OBO tokens for all SPs in the workspace without explicit permissions.
diff --git a/packages/sharing/NEXT_CHANGELOG.md b/packages/sharing/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/sharing/NEXT_CHANGELOG.md
+++ b/packages/sharing/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/sharing/src/v1/model.ts b/packages/sharing/src/v1/model.ts
index d63f239a4..928db52df 100644
--- a/packages/sharing/src/v1/model.ts
+++ b/packages/sharing/src/v1/model.ts
@@ -9,7 +9,7 @@ import {z} from 'zod';
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ColumnTypeName = {
-  COLUMN_TYPE_NAME_UNSPECIFIED: 'COLUMN_TYPE_NAME_UNSPECIFIED',
+  COLUMN_TYPE_NAME_UNSPECIFIED: '',
   BOOLEAN: 'BOOLEAN',
   BYTE: 'BYTE',
   SHORT: 'SHORT',
@@ -55,7 +55,7 @@ export type DeltaSharingAuthenticationType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const FunctionParameterMode = {
-  FUNCTION_PARAMETER_MODE_UNSPECIFIED: 'FUNCTION_PARAMETER_MODE_UNSPECIFIED',
+  FUNCTION_PARAMETER_MODE_UNSPECIFIED: '',
   IN: 'IN',
   OUT: 'OUT',
   INOUT: 'INOUT',
@@ -66,7 +66,7 @@ export type FunctionParameterMode =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const FunctionParameterType = {
-  FUNCTION_PARAMETER_TYPE_UNSPECIFIED: 'FUNCTION_PARAMETER_TYPE_UNSPECIFIED',
+  FUNCTION_PARAMETER_TYPE_UNSPECIFIED: '',
   PARAM: 'PARAM',
   COLUMN: 'COLUMN',
 } as const;
@@ -77,7 +77,7 @@ export type FunctionParameterType =
 /** The SecurableKind of a delta-shared object. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SharedSecurableKind = {
-  SHARED_SECURABLE_KIND_UNSPECIFIED: 'SHARED_SECURABLE_KIND_UNSPECIFIED',
+  SHARED_SECURABLE_KIND_UNSPECIFIED: '',
   FUNCTION_STANDARD: 'FUNCTION_STANDARD',
   FUNCTION_REGISTERED_MODEL: 'FUNCTION_REGISTERED_MODEL',
   FUNCTION_FEATURE_SPEC: 'FUNCTION_FEATURE_SPEC',
diff --git a/packages/statementexecution/NEXT_CHANGELOG.md b/packages/statementexecution/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/statementexecution/NEXT_CHANGELOG.md
+++ b/packages/statementexecution/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/statementexecution/src/v1/model.ts b/packages/statementexecution/src/v1/model.ts
index 53fd3bccb..0d6b79873 100644
--- a/packages/statementexecution/src/v1/model.ts
+++ b/packages/statementexecution/src/v1/model.ts
@@ -43,7 +43,7 @@ export type ColumnTypeName =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Disposition = {
-  FETCH_DISPOSITION_UNSPECIFIED: 'FETCH_DISPOSITION_UNSPECIFIED',
+  FETCH_DISPOSITION_UNSPECIFIED: '',
   INLINE: 'INLINE',
   EXTERNAL_LINKS: 'EXTERNAL_LINKS',
 } as const;
@@ -53,7 +53,7 @@ export type Disposition =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Format = {
-  FORMAT_UNSPECIFIED: 'FORMAT_UNSPECIFIED',
+  FORMAT_UNSPECIFIED: '',
   JSON_ARRAY: 'JSON_ARRAY',
   ARROW_STREAM: 'ARROW_STREAM',
   CSV: 'CSV',
@@ -90,7 +90,7 @@ export type ServiceErrorCode =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const TimeoutAction = {
-  TIMEOUT_ACTION_UNSPECIFIED: 'TIMEOUT_ACTION_UNSPECIFIED',
+  TIMEOUT_ACTION_UNSPECIFIED: '',
   CONTINUE: 'CONTINUE',
   CANCEL: 'CANCEL',
 } as const;
@@ -100,7 +100,7 @@ export type TimeoutAction =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const StatementStatus_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   PENDING: 'PENDING',
   RUNNING: 'RUNNING',
   SUCCEEDED: 'SUCCEEDED',
diff --git a/packages/tokenmanagement/NEXT_CHANGELOG.md b/packages/tokenmanagement/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/tokenmanagement/NEXT_CHANGELOG.md
+++ b/packages/tokenmanagement/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/tokenmanagement/src/v1/model.ts b/packages/tokenmanagement/src/v1/model.ts
index 3813d4863..9c58b0472 100644
--- a/packages/tokenmanagement/src/v1/model.ts
+++ b/packages/tokenmanagement/src/v1/model.ts
@@ -12,7 +12,7 @@ import {z} from 'zod';
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AutoscopeState = {
-  AUTOSCOPE_STATE_UNSPECIFIED: 'AUTOSCOPE_STATE_UNSPECIFIED',
+  AUTOSCOPE_STATE_UNSPECIFIED: '',
   AUTOSCOPE_STATE_DISABLED: 'AUTOSCOPE_STATE_DISABLED',
   AUTOSCOPE_STATE_RUNNING: 'AUTOSCOPE_STATE_RUNNING',
   AUTOSCOPE_STATE_COMPLETED: 'AUTOSCOPE_STATE_COMPLETED',
diff --git a/packages/tokens/NEXT_CHANGELOG.md b/packages/tokens/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/tokens/NEXT_CHANGELOG.md
+++ b/packages/tokens/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/tokens/src/v1/model.ts b/packages/tokens/src/v1/model.ts
index 6a6965066..7f3badb7d 100644
--- a/packages/tokens/src/v1/model.ts
+++ b/packages/tokens/src/v1/model.ts
@@ -12,7 +12,7 @@ import {z} from 'zod';
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const AutoscopeState = {
-  AUTOSCOPE_STATE_UNSPECIFIED: 'AUTOSCOPE_STATE_UNSPECIFIED',
+  AUTOSCOPE_STATE_UNSPECIFIED: '',
   AUTOSCOPE_STATE_DISABLED: 'AUTOSCOPE_STATE_DISABLED',
   AUTOSCOPE_STATE_RUNNING: 'AUTOSCOPE_STATE_RUNNING',
   AUTOSCOPE_STATE_COMPLETED: 'AUTOSCOPE_STATE_COMPLETED',
diff --git a/packages/uc/abacpolicies/NEXT_CHANGELOG.md b/packages/uc/abacpolicies/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/abacpolicies/NEXT_CHANGELOG.md
+++ b/packages/uc/abacpolicies/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/abacpolicies/src/v1/model.ts b/packages/uc/abacpolicies/src/v1/model.ts
index eb366abe5..adbf480f3 100644
--- a/packages/uc/abacpolicies/src/v1/model.ts
+++ b/packages/uc/abacpolicies/src/v1/model.ts
@@ -7,7 +7,7 @@ import {z} from 'zod';
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PolicyType = {
   /** For detecting field not being set to a supported value */
-  POLICY_TYPE_UNSPECIFIED: 'POLICY_TYPE_UNSPECIFIED',
+  POLICY_TYPE_UNSPECIFIED: '',
   POLICY_TYPE_ROW_FILTER: 'POLICY_TYPE_ROW_FILTER',
   POLICY_TYPE_COLUMN_MASK: 'POLICY_TYPE_COLUMN_MASK',
 } as const;
diff --git a/packages/uc/artifactallowlists/NEXT_CHANGELOG.md b/packages/uc/artifactallowlists/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/artifactallowlists/NEXT_CHANGELOG.md
+++ b/packages/uc/artifactallowlists/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/artifactallowlists/src/v1/model.ts b/packages/uc/artifactallowlists/src/v1/model.ts
index 13ca59cfc..df152ada7 100644
--- a/packages/uc/artifactallowlists/src/v1/model.ts
+++ b/packages/uc/artifactallowlists/src/v1/model.ts
@@ -5,7 +5,7 @@ import {z} from 'zod';
 /** The artifact type */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ArtifactType = {
-  ARTIFACT_TYPE_UNSPECIFIED: 'ARTIFACT_TYPE_UNSPECIFIED',
+  ARTIFACT_TYPE_UNSPECIFIED: '',
   INIT_SCRIPT: 'INIT_SCRIPT',
   LIBRARY_JAR: 'LIBRARY_JAR',
   LIBRARY_MAVEN: 'LIBRARY_MAVEN',
@@ -18,7 +18,7 @@ export type ArtifactType =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ArtifactMatcher_MatchType = {
   /** In the future, we will add EXACT_MATCH, WILDCARDS, and more types */
-  MATCH_TYPE_UNSPECIFIED: 'MATCH_TYPE_UNSPECIFIED',
+  MATCH_TYPE_UNSPECIFIED: '',
   PREFIX_MATCH: 'PREFIX_MATCH',
 } as const;
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Proto-style nested enum name.
diff --git a/packages/uc/catalogs/NEXT_CHANGELOG.md b/packages/uc/catalogs/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/catalogs/NEXT_CHANGELOG.md
+++ b/packages/uc/catalogs/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/catalogs/src/v1/model.ts b/packages/uc/catalogs/src/v1/model.ts
index 62ac1cd96..7a0ea7a27 100644
--- a/packages/uc/catalogs/src/v1/model.ts
+++ b/packages/uc/catalogs/src/v1/model.ts
@@ -53,7 +53,7 @@ export type SecurableType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ProvisioningInfo_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   PROVISIONING: 'PROVISIONING',
   ACTIVE: 'ACTIVE',
   FAILED: 'FAILED',
diff --git a/packages/uc/connections/NEXT_CHANGELOG.md b/packages/uc/connections/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/connections/NEXT_CHANGELOG.md
+++ b/packages/uc/connections/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/connections/src/v1/model.ts b/packages/uc/connections/src/v1/model.ts
index 0488bbb21..7ebcc9a44 100644
--- a/packages/uc/connections/src/v1/model.ts
+++ b/packages/uc/connections/src/v1/model.ts
@@ -89,7 +89,7 @@ export type SecurableType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ProvisioningInfo_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   PROVISIONING: 'PROVISIONING',
   ACTIVE: 'ACTIVE',
   FAILED: 'FAILED',
diff --git a/packages/uc/credentials/NEXT_CHANGELOG.md b/packages/uc/credentials/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/credentials/NEXT_CHANGELOG.md
+++ b/packages/uc/credentials/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/credentials/src/v1/model.ts b/packages/uc/credentials/src/v1/model.ts
index 30341e48d..1d01ffe70 100644
--- a/packages/uc/credentials/src/v1/model.ts
+++ b/packages/uc/credentials/src/v1/model.ts
@@ -4,7 +4,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const IsolationMode = {
-  ISOLATION_MODE_UNSPECIFIED: 'ISOLATION_MODE_UNSPECIFIED',
+  ISOLATION_MODE_UNSPECIFIED: '',
   ISOLATION_MODE_OPEN: 'ISOLATION_MODE_OPEN',
   ISOLATION_MODE_ISOLATED: 'ISOLATION_MODE_ISOLATED',
 } as const;
diff --git a/packages/uc/entitytagassignments/NEXT_CHANGELOG.md b/packages/uc/entitytagassignments/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/entitytagassignments/NEXT_CHANGELOG.md
+++ b/packages/uc/entitytagassignments/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/entitytagassignments/src/v1/model.ts b/packages/uc/entitytagassignments/src/v1/model.ts
index cc3bc74af..8f63b7e22 100644
--- a/packages/uc/entitytagassignments/src/v1/model.ts
+++ b/packages/uc/entitytagassignments/src/v1/model.ts
@@ -9,8 +9,7 @@ import {z} from 'zod';
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const TagAssignmentSourceType = {
   /** Includes (but not limited to) tags manually assigned by users */
-  TAG_ASSIGNMENT_SOURCE_TYPE_UNSPECIFIED:
-    'TAG_ASSIGNMENT_SOURCE_TYPE_UNSPECIFIED',
+  TAG_ASSIGNMENT_SOURCE_TYPE_UNSPECIFIED: '',
   /** Automatically assigned by Data Classification */
   TAG_ASSIGNMENT_SOURCE_TYPE_SYSTEM_DATA_CLASSIFICATION:
     'TAG_ASSIGNMENT_SOURCE_TYPE_SYSTEM_DATA_CLASSIFICATION',
diff --git a/packages/uc/externallineage/NEXT_CHANGELOG.md b/packages/uc/externallineage/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/externallineage/NEXT_CHANGELOG.md
+++ b/packages/uc/externallineage/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/externallineage/src/v1/model.ts b/packages/uc/externallineage/src/v1/model.ts
index 386702ef0..40930dd68 100644
--- a/packages/uc/externallineage/src/v1/model.ts
+++ b/packages/uc/externallineage/src/v1/model.ts
@@ -7,7 +7,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SystemType = {
-  SYSTEM_TYPE_UNSPECIFIED: 'SYSTEM_TYPE_UNSPECIFIED',
+  SYSTEM_TYPE_UNSPECIFIED: '',
   OTHER: 'OTHER',
   TABLEAU: 'TABLEAU',
   POWER_BI: 'POWER_BI',
@@ -38,7 +38,7 @@ export type SystemType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const Direction_LineageDirection = {
-  LINEAGE_DIRECTION_UNSPECIFIED: 'LINEAGE_DIRECTION_UNSPECIFIED',
+  LINEAGE_DIRECTION_UNSPECIFIED: '',
   UPSTREAM: 'UPSTREAM',
   DOWNSTREAM: 'DOWNSTREAM',
 } as const;
diff --git a/packages/uc/externallocations/NEXT_CHANGELOG.md b/packages/uc/externallocations/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/externallocations/NEXT_CHANGELOG.md
+++ b/packages/uc/externallocations/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/externallocations/src/v1/model.ts b/packages/uc/externallocations/src/v1/model.ts
index 7be0bd8fd..c8073a8f4 100644
--- a/packages/uc/externallocations/src/v1/model.ts
+++ b/packages/uc/externallocations/src/v1/model.ts
@@ -4,7 +4,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const IsolationMode = {
-  ISOLATION_MODE_UNSPECIFIED: 'ISOLATION_MODE_UNSPECIFIED',
+  ISOLATION_MODE_UNSPECIFIED: '',
   ISOLATION_MODE_OPEN: 'ISOLATION_MODE_OPEN',
   ISOLATION_MODE_ISOLATED: 'ISOLATION_MODE_ISOLATED',
 } as const;
@@ -14,7 +14,7 @@ export type IsolationMode =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SseEncryptionAlgorithm = {
-  SSE_ENCRYPTION_ALGORITHM_UNSPECIFIED: 'SSE_ENCRYPTION_ALGORITHM_UNSPECIFIED',
+  SSE_ENCRYPTION_ALGORITHM_UNSPECIFIED: '',
   AWS_SSE_S3: 'AWS_SSE_S3',
   AWS_SSE_KMS: 'AWS_SSE_KMS',
 } as const;
diff --git a/packages/uc/externalmetadata/NEXT_CHANGELOG.md b/packages/uc/externalmetadata/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/externalmetadata/NEXT_CHANGELOG.md
+++ b/packages/uc/externalmetadata/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/externalmetadata/src/v1/model.ts b/packages/uc/externalmetadata/src/v1/model.ts
index a2d3bd4cd..7ad10f499 100644
--- a/packages/uc/externalmetadata/src/v1/model.ts
+++ b/packages/uc/externalmetadata/src/v1/model.ts
@@ -7,7 +7,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SystemType = {
-  SYSTEM_TYPE_UNSPECIFIED: 'SYSTEM_TYPE_UNSPECIFIED',
+  SYSTEM_TYPE_UNSPECIFIED: '',
   OTHER: 'OTHER',
   TABLEAU: 'TABLEAU',
   POWER_BI: 'POWER_BI',
diff --git a/packages/uc/onlinetables/NEXT_CHANGELOG.md b/packages/uc/onlinetables/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/onlinetables/NEXT_CHANGELOG.md
+++ b/packages/uc/onlinetables/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/onlinetables/src/v1/model.ts b/packages/uc/onlinetables/src/v1/model.ts
index d697bbca0..f775065f1 100644
--- a/packages/uc/onlinetables/src/v1/model.ts
+++ b/packages/uc/onlinetables/src/v1/model.ts
@@ -7,7 +7,7 @@ import {z} from 'zod';
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const OnlineTableState = {
   /** The default state. It should not be reported by any online tables. */
-  ONLINE_TABLE_STATE_UNSPECIFIED: 'ONLINE_TABLE_STATE_UNSPECIFIED',
+  ONLINE_TABLE_STATE_UNSPECIFIED: '',
   /**
    * The online table has just been created and resources are being provisioned. This is also the
    * catch-all state if there is not a more suitable state to report for the online table.
@@ -59,7 +59,7 @@ export type OnlineTableState =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ProvisioningInfo_State = {
-  STATE_UNSPECIFIED: 'STATE_UNSPECIFIED',
+  STATE_UNSPECIFIED: '',
   PROVISIONING: 'PROVISIONING',
   ACTIVE: 'ACTIVE',
   FAILED: 'FAILED',
diff --git a/packages/uc/rfa/NEXT_CHANGELOG.md b/packages/uc/rfa/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/rfa/NEXT_CHANGELOG.md
+++ b/packages/uc/rfa/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/rfa/src/v1/model.ts b/packages/uc/rfa/src/v1/model.ts
index 049aa98b3..9bbdf795d 100644
--- a/packages/uc/rfa/src/v1/model.ts
+++ b/packages/uc/rfa/src/v1/model.ts
@@ -6,7 +6,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const DestinationType = {
-  DESTINATION_TYPE_UNSPECIFIED: 'DESTINATION_TYPE_UNSPECIFIED',
+  DESTINATION_TYPE_UNSPECIFIED: '',
   EMAIL: 'EMAIL',
   SLACK: 'SLACK',
   GENERIC_WEBHOOK: 'GENERIC_WEBHOOK',
@@ -19,7 +19,7 @@ export type DestinationType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const PrincipalType = {
-  PRINCIPAL_TYPE_UNSPECIFIED: 'PRINCIPAL_TYPE_UNSPECIFIED',
+  PRINCIPAL_TYPE_UNSPECIFIED: '',
   USER_PRINCIPAL: 'USER_PRINCIPAL',
   GROUP_PRINCIPAL: 'GROUP_PRINCIPAL',
   SERVICE_PRINCIPAL: 'SERVICE_PRINCIPAL',
@@ -56,7 +56,7 @@ export type SecurableType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SpecialDestination = {
-  SPECIAL_DESTINATION_UNSPECIFIED: 'SPECIAL_DESTINATION_UNSPECIFIED',
+  SPECIAL_DESTINATION_UNSPECIFIED: '',
   SPECIAL_DESTINATION_CATALOG_OWNER: 'SPECIAL_DESTINATION_CATALOG_OWNER',
   SPECIAL_DESTINATION_EXTERNAL_LOCATION_OWNER:
     'SPECIAL_DESTINATION_EXTERNAL_LOCATION_OWNER',
diff --git a/packages/uc/tables/NEXT_CHANGELOG.md b/packages/uc/tables/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/tables/NEXT_CHANGELOG.md
+++ b/packages/uc/tables/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/tables/src/v1/model.ts b/packages/uc/tables/src/v1/model.ts
index 779cd79be..583986997 100644
--- a/packages/uc/tables/src/v1/model.ts
+++ b/packages/uc/tables/src/v1/model.ts
@@ -213,7 +213,7 @@ export type SecurableType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SseEncryptionAlgorithm = {
-  SSE_ENCRYPTION_ALGORITHM_UNSPECIFIED: 'SSE_ENCRYPTION_ALGORITHM_UNSPECIFIED',
+  SSE_ENCRYPTION_ALGORITHM_UNSPECIFIED: '',
   AWS_SSE_S3: 'AWS_SSE_S3',
   AWS_SSE_KMS: 'AWS_SSE_KMS',
 } as const;
@@ -246,7 +246,7 @@ export type TableType =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const OptionSpec_OauthStage = {
-  OAUTH_STAGE_UNSPECIFIED: 'OAUTH_STAGE_UNSPECIFIED',
+  OAUTH_STAGE_UNSPECIFIED: '',
   BEFORE_AUTHORIZATION_CODE: 'BEFORE_AUTHORIZATION_CODE',
   BEFORE_ACCESS_TOKEN: 'BEFORE_ACCESS_TOKEN',
 } as const;
@@ -263,7 +263,7 @@ export type OptionSpec_OauthStage =
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const OptionSpec_OptionType = {
-  OPTION_TYPE_UNSPECIFIED: 'OPTION_TYPE_UNSPECIFIED',
+  OPTION_TYPE_UNSPECIFIED: '',
   OPTION_BOOLEAN: 'OPTION_BOOLEAN',
   OPTION_NUMBER: 'OPTION_NUMBER',
   OPTION_BIGINT: 'OPTION_BIGINT',
diff --git a/packages/uc/volumes/NEXT_CHANGELOG.md b/packages/uc/volumes/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/volumes/NEXT_CHANGELOG.md
+++ b/packages/uc/volumes/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/volumes/src/v1/model.ts b/packages/uc/volumes/src/v1/model.ts
index 85887aee2..325bf0f1f 100644
--- a/packages/uc/volumes/src/v1/model.ts
+++ b/packages/uc/volumes/src/v1/model.ts
@@ -4,7 +4,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const SseEncryptionAlgorithm = {
-  SSE_ENCRYPTION_ALGORITHM_UNSPECIFIED: 'SSE_ENCRYPTION_ALGORITHM_UNSPECIFIED',
+  SSE_ENCRYPTION_ALGORITHM_UNSPECIFIED: '',
   AWS_SSE_S3: 'AWS_SSE_S3',
   AWS_SSE_KMS: 'AWS_SSE_KMS',
 } as const;
diff --git a/packages/uc/workspacebindings/NEXT_CHANGELOG.md b/packages/uc/workspacebindings/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/uc/workspacebindings/NEXT_CHANGELOG.md
+++ b/packages/uc/workspacebindings/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/uc/workspacebindings/src/v1/model.ts b/packages/uc/workspacebindings/src/v1/model.ts
index b1f16183f..28e57f6ee 100644
--- a/packages/uc/workspacebindings/src/v1/model.ts
+++ b/packages/uc/workspacebindings/src/v1/model.ts
@@ -5,7 +5,7 @@ import {z} from 'zod';
 /** Using `BINDING_TYPE_` prefix here to avoid conflict with `TableOperation` enum in `credentials_common.proto`. */
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const BindingType = {
-  BINDING_TYPE_UNSPECIFIED: 'BINDING_TYPE_UNSPECIFIED',
+  BINDING_TYPE_UNSPECIFIED: '',
   BINDING_TYPE_READ_WRITE: 'BINDING_TYPE_READ_WRITE',
   BINDING_TYPE_READ_ONLY: 'BINDING_TYPE_READ_ONLY',
 } as const;
diff --git a/packages/usagedashboards/NEXT_CHANGELOG.md b/packages/usagedashboards/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/usagedashboards/NEXT_CHANGELOG.md
+++ b/packages/usagedashboards/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/usagedashboards/src/v1/model.ts b/packages/usagedashboards/src/v1/model.ts
index 4d1d58dcb..62a5d08f9 100644
--- a/packages/usagedashboards/src/v1/model.ts
+++ b/packages/usagedashboards/src/v1/model.ts
@@ -4,8 +4,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const UsageDashboardMajorVersion = {
-  USAGE_DASHBOARD_MAJOR_VERSION_UNSPECIFIED:
-    'USAGE_DASHBOARD_MAJOR_VERSION_UNSPECIFIED',
+  USAGE_DASHBOARD_MAJOR_VERSION_UNSPECIFIED: '',
   USAGE_DASHBOARD_MAJOR_VERSION_1: 'USAGE_DASHBOARD_MAJOR_VERSION_1',
   USAGE_DASHBOARD_MAJOR_VERSION_2: 'USAGE_DASHBOARD_MAJOR_VERSION_2',
 } as const;
@@ -15,7 +14,7 @@ export type UsageDashboardMajorVersion =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const UsageDashboardType = {
-  USAGE_DASHBOARD_TYPE_UNSPECIFIED: 'USAGE_DASHBOARD_TYPE_UNSPECIFIED',
+  USAGE_DASHBOARD_TYPE_UNSPECIFIED: '',
   USAGE_DASHBOARD_TYPE_WORKSPACE: 'USAGE_DASHBOARD_TYPE_WORKSPACE',
   USAGE_DASHBOARD_TYPE_GLOBAL: 'USAGE_DASHBOARD_TYPE_GLOBAL',
 } as const;
diff --git a/packages/vectorsearch/NEXT_CHANGELOG.md b/packages/vectorsearch/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/vectorsearch/NEXT_CHANGELOG.md
+++ b/packages/vectorsearch/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/vectorsearch/src/v1/model.ts b/packages/vectorsearch/src/v1/model.ts
index 24ae016ef..d8230120b 100644
--- a/packages/vectorsearch/src/v1/model.ts
+++ b/packages/vectorsearch/src/v1/model.ts
@@ -57,7 +57,7 @@ export type PipelineType =
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ScalingChangeState = {
-  SCALING_CHANGE_UNSPECIFIED: 'SCALING_CHANGE_UNSPECIFIED',
+  SCALING_CHANGE_UNSPECIFIED: '',
   SCALING_CHANGE_APPLIED: 'SCALING_CHANGE_APPLIED',
   SCALING_CHANGE_IN_PROGRESS: 'SCALING_CHANGE_IN_PROGRESS',
 } as const;
diff --git a/packages/warehouses/NEXT_CHANGELOG.md b/packages/warehouses/NEXT_CHANGELOG.md
index ef75b11eb..99647e9da 100644
--- a/packages/warehouses/NEXT_CHANGELOG.md
+++ b/packages/warehouses/NEXT_CHANGELOG.md
@@ -11,3 +11,5 @@
 ### Internal Changes
 
 ### API Changes
+
+- **Breaking (beta correction):** Unspecified enum constants now equal `""` because they represent absence and must not expose a sendable sentinel wire value.
diff --git a/packages/warehouses/src/v1/model.ts b/packages/warehouses/src/v1/model.ts
index 8197c2d1b..686d2022c 100644
--- a/packages/warehouses/src/v1/model.ts
+++ b/packages/warehouses/src/v1/model.ts
@@ -6,7 +6,7 @@ import {z} from 'zod';
 
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const ChannelName = {
-  CHANNEL_NAME_UNSPECIFIED: 'CHANNEL_NAME_UNSPECIFIED',
+  CHANNEL_NAME_UNSPECIFIED: '',
   CHANNEL_NAME_PREVIEW: 'CHANNEL_NAME_PREVIEW',
   CHANNEL_NAME_CURRENT: 'CHANNEL_NAME_CURRENT',
   CHANNEL_NAME_PREVIOUS: 'CHANNEL_NAME_PREVIOUS',
@@ -20,8 +20,7 @@ export type ChannelName =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const DefaultWarehouseOverrideType = {
   /** Unspecified default warehouse override type. */
-  DEFAULT_WAREHOUSE_OVERRIDE_TYPE_UNSPECIFIED:
-    'DEFAULT_WAREHOUSE_OVERRIDE_TYPE_UNSPECIFIED',
+  DEFAULT_WAREHOUSE_OVERRIDE_TYPE_UNSPECIFIED: '',
   /** The user should remember their last-selected warehouse. */
   LAST_SELECTED: 'LAST_SELECTED',
   /** The user should use a specific warehouse. */
@@ -82,7 +81,7 @@ export const EndpointSpotInstancePolicy = {
    * This follows Google APIs:
    * https://cloud.google.com/apis/design/design_patterns#enum_default_value.
    */
-  POLICY_UNSPECIFIED: 'POLICY_UNSPECIFIED',
+  POLICY_UNSPECIFIED: '',
   /** COST_OPTIMIZED to prefer spot instance. */
   COST_OPTIMIZED: 'COST_OPTIMIZED',
   /** RELIABILITY_OPTIMIZED to prefer on demand instance. */
@@ -730,7 +729,7 @@ export type TerminationType =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const WarehouseType = {
   /** UNDOCUMENTED. Indicates no value is specified. */
-  TYPE_UNSPECIFIED: 'TYPE_UNSPECIFIED',
+  TYPE_UNSPECIFIED: '',
   /** Classic warehouse type */
   CLASSIC: 'CLASSIC',
   /** Pro warehouse type */
@@ -743,7 +742,7 @@ export type WarehouseType =
 // eslint-disable-next-line @typescript-eslint/naming-convention -- Enum-style const object.
 export const EndpointHealth_Status = {
   /** UNDOCUMENTED. Indicates no value is specified. An implementation detail. */
-  STATUS_UNSPECIFIED: 'STATUS_UNSPECIFIED',
+  STATUS_UNSPECIFIED: '',
   /** Endpoint is functioning normally and there are no known issues. */
   HEALTHY: 'HEALTHY',
   /**