diff --git a/temporal/api/workflowservice/v1/request_response.proto b/temporal/api/workflowservice/v1/request_response.proto
index 69b673c81..aba42496d 100644
--- a/temporal/api/workflowservice/v1/request_response.proto
+++ b/temporal/api/workflowservice/v1/request_response.proto
@@ -269,6 +269,8 @@ message PollWorkflowTaskQueueRequest {
     // Worker deployment options that user has set in the worker.
     // Experimental. Worker Deployments are experimental and might significantly change in the future.
     temporal.api.deployment.v1.WorkerDeploymentOptions deployment_options = 6;
+    // A unique key for this worker instance, used for tracking worker lifecycle.
+    string worker_instance_key = 7;
 }
 
 message PollWorkflowTaskQueueResponse {
@@ -440,6 +442,8 @@ message PollActivityTaskQueueRequest {
     temporal.api.common.v1.WorkerVersionCapabilities worker_version_capabilities = 5 [deprecated = true];
     // Worker deployment options that user has set in the worker.
     temporal.api.deployment.v1.WorkerDeploymentOptions deployment_options = 6;
+    // A unique key for this worker instance, used for tracking worker lifecycle.
+    string worker_instance_key = 7;
 }
 
 message PollActivityTaskQueueResponse {
@@ -999,11 +1003,17 @@ message ResetStickyTaskQueueResponse {
 
 message ShutdownWorkerRequest {
     string namespace = 1;
+    // sticky_task_queue may not always be populated. We want to ensure all workers
+    // send a shutdown request to update worker state for heartbeating, as well
+    // as cancel pending poll calls early, instead of waiting for timeouts.
     string sticky_task_queue = 2;
     string identity = 3;
     string reason = 4;
-
     temporal.api.worker.v1.WorkerHeartbeat worker_heartbeat = 5;
+    // Technically this is also sent in the WorkerHeartbeat, but
+    // since worker heartbeating can be turned off, this needs
+    // to be a separate, top-level field.
+    string worker_instance_key = 6;
 }
 
 message ShutdownWorkerResponse {
@@ -1761,6 +1771,8 @@ message PollWorkflowExecutionUpdateRequest {
     // Specifies client's intent to wait for Update results.
     // Omit to request a non-blocking poll.
     temporal.api.update.v1.WaitPolicy wait_policy = 4;
+    // A unique key for this worker instance, used for tracking worker lifecycle.
+    string worker_instance_key = 8;
 }
 
 message PollWorkflowExecutionUpdateResponse {
@@ -1799,6 +1811,8 @@ message PollNexusTaskQueueRequest {
 
     // Worker info to be sent to the server.
     repeated temporal.api.worker.v1.WorkerHeartbeat worker_heartbeat = 7;
+    // A unique key for this worker instance, used for tracking worker lifecycle.
+    string worker_instance_key = 8;
 }
 
 message PollNexusTaskQueueResponse {