diff --git a/lib/cluster-adapter.ts b/lib/cluster-adapter.ts
index c2e2161..b9df678 100644
--- a/lib/cluster-adapter.ts
+++ b/lib/cluster-adapter.ts
@@ -1,4 +1,9 @@
-import { Adapter, BroadcastOptions, Room } from "./index";
+import {
+  Adapter,
+  type BroadcastFlags,
+  type BroadcastOptions,
+  type Room,
+} from "./index";
 import { debug as debugModule } from "debug";
 import { randomBytes } from "crypto";
 
@@ -10,6 +15,10 @@ function randomId() {
   return randomBytes(8).toString("hex");
 }
 
+type DistributiveOmit<T, K extends keyof any> = T extends any
+  ? Omit<T, K>
+  : never;
+
 export interface ClusterAdapterOptions {
   /**
    * The number of ms between two heartbeats.
@@ -38,11 +47,50 @@ export enum MessageType {
   BROADCAST_ACK,
 }
 
-export interface ClusterMessage {
+export type ClusterMessage = {
   uid: string;
-  type: MessageType;
-  data?: Record<string, unknown>;
-}
+  nsp: string;
+} & (
+  | {
+      type: MessageType.INITIAL_HEARTBEAT | MessageType.HEARTBEAT;
+    }
+  | {
+      type: MessageType.BROADCAST;
+      data: {
+        opts: { rooms: string[]; except: string[]; flags: BroadcastFlags };
+        packet: unknown;
+        requestId?: string;
+      };
+    }
+  | {
+      type: MessageType.SOCKETS_JOIN | MessageType.SOCKETS_LEAVE;
+      data: {
+        opts: { rooms: string[]; except: string[]; flags: BroadcastFlags };
+        rooms: string[];
+      };
+    }
+  | {
+      type: MessageType.DISCONNECT_SOCKETS;
+      data: {
+        opts: { rooms: string[]; except: string[]; flags: BroadcastFlags };
+        close?: boolean;
+      };
+    }
+  | {
+      type: MessageType.FETCH_SOCKETS;
+      data: {
+        opts: { rooms: string[]; except: string[]; flags: BroadcastFlags };
+        requestId: string;
+      };
+    }
+  | {
+      type: MessageType.SERVER_SIDE_EMIT;
+      data: {
+        requestId?: string;
+        packet: unknown;
+      };
+    }
+);
 
 interface ClusterRequest {
   type: MessageType;
@@ -53,13 +101,39 @@ interface ClusterRequest {
   responses: any[];
 }
 
-interface ClusterResponse {
-  type: MessageType;
-  data: {
-    requestId: string;
-    [key: string]: unknown;
-  };
-}
+export type ClusterResponse = {
+  uid: string;
+  nsp: string;
+} & (
+  | {
+      type: MessageType.FETCH_SOCKETS_RESPONSE;
+      data: {
+        requestId: string;
+        sockets: unknown[];
+      };
+    }
+  | {
+      type: MessageType.SERVER_SIDE_EMIT_RESPONSE;
+      data: {
+        requestId: string;
+        packet: unknown;
+      };
+    }
+  | {
+      type: MessageType.BROADCAST_CLIENT_COUNT;
+      data: {
+        requestId: string;
+        clientCount: number;
+      };
+    }
+  | {
+      type: MessageType.BROADCAST_ACK;
+      data: {
+        requestId: string;
+        packet: unknown;
+      };
+    }
+);
 
 interface ClusterAckRequest {
   clientCountCallback: (clientCount: number) => void;
@@ -85,7 +159,7 @@ function decodeOptions(opts): BroadcastOptions {
 /**
  * A cluster-ready adapter. Any extending class must:
  *
- * - implement {@link ClusterAdapter#publishMessage} and {@link ClusterAdapter#publishResponse}
+ * - implement {@link ClusterAdapter#doPublish} and {@link ClusterAdapter#doPublishResponse}
  * - call {@link ClusterAdapter#onMessage} and {@link ClusterAdapter#onResponse}
  */
 export abstract class ClusterAdapter extends Adapter {
@@ -125,7 +199,7 @@ export abstract class ClusterAdapter extends Adapter {
               this.publishResponse(message.uid, {
                 type: MessageType.BROADCAST_CLIENT_COUNT,
                 data: {
-                  requestId: message.data.requestId as string,
+                  requestId: message.data.requestId,
                   clientCount,
                 },
               });
@@ -135,7 +209,7 @@ export abstract class ClusterAdapter extends Adapter {
               this.publishResponse(message.uid, {
                 type: MessageType.BROADCAST_ACK,
                 data: {
-                  requestId: message.data.requestId as string,
+                  requestId: message.data.requestId,
                   packet: arg,
                 },
               });
@@ -153,23 +227,17 @@ export abstract class ClusterAdapter extends Adapter {
       }
 
       case MessageType.SOCKETS_JOIN:
-        super.addSockets(
-          decodeOptions(message.data.opts),
-          message.data.rooms as string[]
-        );
+        super.addSockets(decodeOptions(message.data.opts), message.data.rooms);
         break;
 
       case MessageType.SOCKETS_LEAVE:
-        super.delSockets(
-          decodeOptions(message.data.opts),
-          message.data.rooms as string[]
-        );
+        super.delSockets(decodeOptions(message.data.opts), message.data.rooms);
         break;
 
       case MessageType.DISCONNECT_SOCKETS:
         super.disconnectSockets(
           decodeOptions(message.data.opts),
-          message.data.close as boolean
+          message.data.close
         );
         break;
 
@@ -182,7 +250,7 @@ export abstract class ClusterAdapter extends Adapter {
         this.publishResponse(message.uid, {
           type: MessageType.FETCH_SOCKETS_RESPONSE,
           data: {
-            requestId: message.data.requestId as string,
+            requestId: message.data.requestId,
             sockets: localSockets.map((socket) => {
               // remove sessionStore from handshake, as it may contain circular references
               const { sessionStore, ...handshake } = socket.handshake;
@@ -216,7 +284,7 @@ export abstract class ClusterAdapter extends Adapter {
           this.publishResponse(message.uid, {
             type: MessageType.SERVER_SIDE_EMIT_RESPONSE,
             data: {
-              requestId: message.data.requestId as string,
+              requestId: message.data.requestId,
               packet: arg,
             },
           });
@@ -247,7 +315,7 @@ export abstract class ClusterAdapter extends Adapter {
       case MessageType.BROADCAST_CLIENT_COUNT: {
         this.ackRequests
           .get(requestId)
-          ?.clientCountCallback(response.data.clientCount as number);
+          ?.clientCountCallback(response.data.clientCount);
         break;
       }
 
@@ -264,7 +332,7 @@ export abstract class ClusterAdapter extends Adapter {
         }
 
         request.current++;
-        (response.data.sockets as any[]).forEach((socket) =>
+        response.data.sockets.forEach((socket) =>
           request.responses.push(socket)
         );
 
@@ -295,6 +363,7 @@ export abstract class ClusterAdapter extends Adapter {
       }
 
       default:
+        // @ts-ignore
         debug("unknown response type: %s", response.type);
     }
   }
@@ -537,11 +606,10 @@ export abstract class ClusterAdapter extends Adapter {
     });
   }
 
-  protected publish(message: Omit<ClusterMessage, "uid">) {
-    return this.publishMessage({
-      uid: this.uid,
-      ...message,
-    });
+  protected publish(message: DistributiveOmit<ClusterMessage, "nsp" | "uid">) {
+    (message as ClusterMessage).uid = this.uid;
+    (message as ClusterMessage).nsp = this.nsp.name;
+    return this.doPublish(message as ClusterMessage);
   }
 
   /**
@@ -551,7 +619,16 @@ export abstract class ClusterAdapter extends Adapter {
    * @protected
    * @return an offset, if applicable
    */
-  protected abstract publishMessage(message: ClusterMessage): Promise<string>;
+  protected abstract doPublish(message: ClusterMessage): Promise<string>;
+
+  protected publishResponse(
+    requesterUid: string,
+    response: Omit<ClusterResponse, "nsp" | "uid">
+  ) {
+    (response as ClusterResponse).uid = this.uid;
+    (response as ClusterResponse).nsp = this.nsp.name;
+    return this.doPublishResponse(requesterUid, response as ClusterResponse);
+  }
 
   /**
    * Send a response to the given member of the cluster.
@@ -560,7 +637,7 @@ export abstract class ClusterAdapter extends Adapter {
    * @param response
    * @protected
    */
-  protected abstract publishResponse(
+  protected abstract doPublishResponse(
     requesterUid: string,
     response: ClusterResponse
   );
@@ -640,7 +717,7 @@ export abstract class ClusterAdapterWithHeartbeat extends ClusterAdapter {
     return Promise.resolve(1 + this.nodesMap.size);
   }
 
-  override publish(message: Omit<ClusterMessage, "uid">) {
+  override publish(message: DistributiveOmit<ClusterMessage, "nsp" | "uid">) {
     this.scheduleHeartbeat();
 
     return super.publish(message);