diff --git a/api/yorkie/v1/yorkie.proto b/api/yorkie/v1/yorkie.proto
index 8ca20e120..285747f00 100644
--- a/api/yorkie/v1/yorkie.proto
+++ b/api/yorkie/v1/yorkie.proto
@@ -48,6 +48,7 @@ message ActivateClientResponse {
 }
 
 message DeactivateClientRequest {
+  string client_key = 2;
   string client_id = 1;
 }
 
@@ -55,6 +56,7 @@ message DeactivateClientResponse {
 }
 
 message AttachDocumentRequest {
+  string client_key = 3;
   string client_id = 1;
   ChangePack change_pack = 2;
 }
@@ -65,6 +67,7 @@ message AttachDocumentResponse {
 }
 
 message DetachDocumentRequest {
+  string client_key = 5;
   string client_id = 1;
   string document_id = 2;
   ChangePack change_pack = 3;
@@ -76,7 +79,9 @@ message DetachDocumentResponse {
 }
 
 message WatchDocumentRequest {
+  string client_key = 4;
   string client_id = 1;
+  string document_key = 3;
   string document_id = 2;
 }
 
@@ -92,6 +97,7 @@ message WatchDocumentResponse {
 }
 
 message RemoveDocumentRequest {
+  string client_key = 4;
   string client_id = 1;
   string document_id = 2;
   ChangePack change_pack = 3;
@@ -102,6 +108,7 @@ message RemoveDocumentResponse {
 }
 
 message PushPullChangesRequest {
+  string client_key = 5;
   string client_id = 1;
   string document_id = 2;
   ChangePack change_pack = 3;
@@ -113,7 +120,9 @@ message PushPullChangesResponse {
 }
 
 message BroadcastRequest {
+  string client_key = 6;
   string client_id = 1;
+  string document_key = 5;
   string document_id = 2;
   string topic = 3;
   bytes payload = 4;