diff --git a/Cargo.lock b/Cargo.lock
index 7ca9de0..e3b5694 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -609,6 +609,19 @@ dependencies = [
  "syn 2.0.15",
 ]
 
+[[package]]
+name = "dashmap"
+version = "5.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "907076dfda823b0b36d2a1bb5f90c96660a5bbcd7729e10727f07858f22c4edc"
+dependencies = [
+ "cfg-if",
+ "hashbrown",
+ "lock_api",
+ "once_cell",
+ "parking_lot_core",
+]
+
 [[package]]
 name = "derive_more"
 version = "0.99.17"
@@ -1793,6 +1806,7 @@ name = "mraow-server"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "dashmap",
  "futures",
  "hyper",
  "mraow-common",
@@ -1805,6 +1819,7 @@ dependencies = [
  "tower",
  "tracing",
  "tracing-subscriber",
+ "uuid",
 ]
 
 [[package]]
diff --git a/proto/chat.proto b/proto/chat.proto
index c56b1bd..c3cb475 100644
--- a/proto/chat.proto
+++ b/proto/chat.proto
@@ -34,7 +34,7 @@ message RoomAction {
 
 service Chat {
   // Rooms
-  rpc roomAction(RoomAction) returns (JoinResponse) {}
+  rpc roomAction(RoomAction) returns (RoomActionResponse) {}
 
   // Messages
   rpc sendMsg(ChatMessage) returns (google.protobuf.Empty) {}
@@ -43,4 +43,4 @@ service Chat {
   // List
   rpc listRooms(google.protobuf.Empty) returns (RoomList) {}
   rpc getAllUsers(google.protobuf.Empty) returns (UserList) {}
-}
\ No newline at end of file
+}
diff --git a/server/Cargo.toml b/server/Cargo.toml
index 321c9e3..af3c16b 100644
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -20,6 +20,8 @@ tracing = "0.1.37"
 tracing-subscriber = { version = "0.3.17", features = ["env-filter"] }
 
 mraow-common = { path = "../common" }
+uuid = { version = "1.3.2", features = ["v4"] }
+dashmap = "5.4.0"
 
 [build-dependencies]
 tonic-build = "0.9.2"
diff --git a/server/src/main.rs b/server/src/main.rs
index 1337057..fda6f5c 100644
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -2,6 +2,7 @@ mod mux;
 
 use futures::Stream;
 use hyper::Body;
+use mux::SharedMux;
 use std::{
   pin::Pin,
   task::{Context, Poll},
@@ -19,7 +20,9 @@ type ResponseStream =
   Pin<Box<dyn Stream<Item = Result<ChatMessage, Status>> + Send>>;
 
 #[derive(Default)]
-pub struct ChatImpl {}
+pub struct ChatImpl {
+  mux: SharedMux,
+}
 
 #[tonic::async_trait]
 impl Chat for ChatImpl {
@@ -41,10 +44,10 @@ impl Chat for ChatImpl {
     todo!()
   }
 
-  async fn receive_msg(
+  async fn receive_msgs(
     &self,
     request: Request<()>,
-  ) -> Result<Response<Self::receiveMsgStream>, Status> {
+  ) -> Result<Response<Self::receiveMsgsStream>, Status> {
     println!("Receive message {request:?}");
     todo!()
   }
diff --git a/server/src/mux.rs b/server/src/mux.rs
index a117078..a100dc7 100644
--- a/server/src/mux.rs
+++ b/server/src/mux.rs
@@ -1,106 +1,32 @@
 use std::{
-  collections::HashMap,
-  pin::Pin,
-  task::{Context, Poll},
+  collections::{HashMap, HashSet},
+  sync::Arc,
 };
 
 use anyhow::Result;
+use dashmap::DashMap;
 use futures::{future, Future, FutureExt, Sink, Stream};
 use tokio::{
   sync::{
     broadcast::{Receiver, Sender},
     mpsc::{self, UnboundedReceiver, UnboundedSender},
+    Mutex,
   },
   task::JoinHandle,
 };
+use uuid::Uuid;
 
-#[derive(Clone)]
-pub struct SharedMux(Mutex<Mux>);
+pub struct UserId(Uuid);
+
+#[derive(Clone, Default)]
+pub struct SharedMux(Arc<Mutex<Mux>>);
 
 /// Shared server state
+#[derive(Default)]
 pub struct Mux {
-  rooms: HashMap<String, Room>,
+  rooms: DashMap<String, Room>,
 }
 
-#[derive(Clone)]
-pub enum RoomMessage {}
-
 pub struct Room {
-  name: String,
-  tx: Sender<RoomMessage>,
-  rx: Receiver<RoomMessage>,
-}
-
-impl Room {
-  pub fn get_handle(&self) -> RoomHandle {
-    RoomHandle {
-      name: self.name.clone(),
-      tx: self.tx.clone(),
-      rx: self.tx.subscribe(),
-    }
-  }
-}
-
-pub struct RoomHandle {
-  name: String,
-  tx: Sender<RoomMessage>,
-  rx: Receiver<RoomMessage>,
-}
-
-pub enum CompositeListenerMessage {
-  Room { name: String, message: RoomMessage },
-  JoinRoom(String),
-  DropRoom(String),
-}
-
-pub struct CompositeListener {
-  current_listening_rooms: HashMap<String, RoomHandle>,
-}
-
-impl CompositeListener {}
-
-/// Create a "composite" listener that listens to multiple rooms / streams, and
-/// is able to add more streams in the middle as well
-pub fn create_listener() -> (
-  JoinHandle<()>,
-  UnboundedSender<CompositeListenerMessage>,
-  UnboundedReceiver<CompositeListenerMessage>,
-) {
-  let (tx, rx) = mpsc::unbounded_channel();
-
-  /*
-  let join_handle = tokio::spawn(async {
-    let mut currently_listening_to: HashMap<String, RoomHandle> =
-      HashMap::new();
-
-    loop {
-      // Build select targets
-      let ouais = rx.recv().boxed();
-      let mut select_targets: Vec<
-        Pin<Box<dyn Future<Output = Option<CompositeListenerMessage>>>>,
-      > = vec![ouais];
-      for (_, room_handle) in currently_listening_to.iter() {
-        select_targets.push(
-          room_handle
-            .rx
-            .recv()
-            .map(|f| {
-              f.ok().map(|m| CompositeListenerMessage::Room {
-                name: room_handle.name.clone(),
-                message: m,
-              })
-            })
-            .boxed(),
-        );
-      }
-
-      // Select
-      let result = future::select_all(select_targets).await;
-    }
-  });
-
-  (join_handle, tx, rx)
-  */
-
-  todo!()
+  members: DashSet<UserId>,
 }