diff --git a/protobuf/README.md b/protobuf/README.md
index f6c9cc4c..81deb0b9 100644
--- a/protobuf/README.md
+++ b/protobuf/README.md
@@ -36,15 +36,6 @@ From within the Azure Functions language worker repo:
     -	`git commit -m "Updated subtree from https://github.com/azure/azure-functions-language-worker-protobuf. Tag: <tag-name>. Commit: <commit hash>"`
     -	`git push`
 
-## Releasing a Language Worker Protobuf version
-
-1.	Draft a release in the GitHub UI
-    -   Be sure to include details of the release
-2.	Create a release version, following semantic versioning guidelines ([semver.org](https://semver.org/))
-3.	Tag the version with the pattern: `v<M>.<m>.<p>-protofile` (example: `v1.1.0-protofile`)
-4.	Merge `dev` to `main`
-5.	Run the release you'd created
-
 ## Consuming FunctionRPC.proto
 *Note: Update versionNumber before running following commands*
 
diff --git a/protobuf/src/proto/FunctionRpc.proto b/protobuf/src/proto/FunctionRpc.proto
index 72f5069a..12809828 100644
--- a/protobuf/src/proto/FunctionRpc.proto
+++ b/protobuf/src/proto/FunctionRpc.proto
@@ -32,6 +32,9 @@ message StreamingMessage {
     WorkerInitRequest worker_init_request = 17;
     // Worker responds after initializing with its capabilities & status
     WorkerInitResponse worker_init_response = 16;
+    
+    // Worker periodically sends empty heartbeat message to host
+    WorkerHeartbeat worker_heartbeat = 15;
 
     // Host sends terminate message to worker.
     // Worker terminates if it can, otherwise host terminates after a grace period
@@ -117,13 +120,35 @@ message WorkerInitRequest {
 
 // Worker responds with the result of initializing itself
 message WorkerInitResponse {
-  // Version of worker
+  // NOT USED
+  // TODO: Remove from protobuf during next breaking change release
   string worker_version = 1;
+
   // A map of worker supported features/capabilities
   map<string, string> capabilities = 2;
 
   // Status of the response
   StatusResult result = 3;
+
+  // Worker metadata captured for telemetry purposes
+  WorkerMetadata worker_metadata = 4;
+}
+
+message WorkerMetadata {
+  // The runtime/stack name
+  string runtime_name = 1;
+
+  // The version of the runtime/stack
+  string runtime_version = 2;
+
+  // The version of the worker
+  string worker_version = 3;
+
+  // The worker bitness/architecture
+  string worker_bitness = 4;
+
+  // Optional additional custom properties
+  map<string, string> custom_properties = 5;
 }
 
 // Used by the host to determine success/failure/cancellation
@@ -134,6 +159,7 @@ message StatusResult {
     Success = 1;
     Cancelled = 2;
   }
+
   // Status for the given result
   Status status = 4;
 
@@ -147,6 +173,10 @@ message StatusResult {
   repeated RpcLog logs = 3;
 }
 
+// NOT USED
+// TODO: Remove from protobuf during next breaking change release
+message WorkerHeartbeat {}
+
 // Warning before killing the process after grace_period
 // Worker self terminates ..no response on this
 message WorkerTerminate {
@@ -291,6 +321,11 @@ message RpcFunctionMetadata {
 
   // A flag indicating if managed dependency is enabled or not
   bool managed_dependency_enabled = 14;
+
+  // Properties for function metadata
+  // They're usually specific to a worker and largely passed along to the controller API for use
+  // outside the host
+   map<string,string> Properties = 16;
 }
 
 // Host tells worker it is ready to receive metadata
@@ -549,11 +584,11 @@ message RpcException {
 
   // Worker specifies whether exception is a user exception, 
   // for purpose of application insights logging. Defaults to false. 
-  optional bool is_user_exception = 4;
+  bool is_user_exception = 4;
 
   // Type of exception. If it's a user exception, the type is passed along to app insights.
   // Otherwise, it's ignored for now.
-  optional string type = 5; 
+  string type = 5; 
 }
 
 // Http cookie type. Note that only name and value are used for Http requests