diff --git a/server/src/db.rs b/server/src/db.rs
index 9b61018701..300c8de6d5 100644
--- a/server/src/db.rs
+++ b/server/src/db.rs
@@ -21,6 +21,12 @@ pub struct Signup {
     pub about: String,
 }
 
+#[derive(Debug, FromRow, Serialize)]
+pub struct Channel {
+    id: i32,
+    pub name: String,
+}
+
 #[derive(Debug, FromRow)]
 pub struct ChannelMessage {
     id: i32,
@@ -158,6 +164,7 @@ impl Db {
 
     // orgs
 
+    #[cfg(test)]
     pub async fn create_org(&self, name: &str, slug: &str) -> Result<OrgId> {
         let query = "
             INSERT INTO orgs (name, slug)
@@ -172,6 +179,7 @@ impl Db {
             .map(OrgId)
     }
 
+    #[cfg(test)]
     pub async fn add_org_member(&self, org_id: OrgId, user_id: UserId) -> Result<()> {
         let query = "
             INSERT INTO org_memberships (org_id, user_id)
@@ -187,6 +195,7 @@ impl Db {
 
     // channels
 
+    #[cfg(test)]
     pub async fn create_org_channel(&self, org_id: OrgId, name: &str) -> Result<ChannelId> {
         let query = "
             INSERT INTO channels (owner_id, owner_is_user, name)
@@ -201,6 +210,42 @@ impl Db {
             .map(ChannelId)
     }
 
+    pub async fn get_channels_for_user(&self, user_id: UserId) -> Result<Vec<Channel>> {
+        let query = "
+            SELECT
+                channels.id, channels.name
+            FROM
+                channel_memberships, channels
+            WHERE
+                channel_memberships.user_id = $1 AND
+                channel_memberships.channel_id = channels.id
+        ";
+        sqlx::query_as(query)
+            .bind(user_id.0)
+            .fetch_all(&self.0)
+            .await
+    }
+
+    pub async fn can_user_access_channel(
+        &self,
+        user_id: UserId,
+        channel_id: ChannelId,
+    ) -> Result<bool> {
+        let query = "
+            SELECT id
+            FROM channel_memberships
+            WHERE user_id = $1 AND channel_id = $2
+            LIMIT 1
+        ";
+        sqlx::query_scalar::<_, i32>(query)
+            .bind(user_id.0)
+            .bind(channel_id.0)
+            .fetch_optional(&self.0)
+            .await
+            .map(|e| e.is_some())
+    }
+
+    #[cfg(test)]
     pub async fn add_channel_member(
         &self,
         channel_id: ChannelId,
@@ -269,6 +314,12 @@ impl std::ops::Deref for Db {
     }
 }
 
+impl Channel {
+    pub fn id(&self) -> ChannelId {
+        ChannelId(self.id)
+    }
+}
+
 impl User {
     pub fn id(&self) -> UserId {
         UserId(self.id)
diff --git a/server/src/rpc.rs b/server/src/rpc.rs
index cd229a3c67..f1ebf605a2 100644
--- a/server/src/rpc.rs
+++ b/server/src/rpc.rs
@@ -1,6 +1,6 @@
 use super::{
     auth::{self, PeerExt as _},
-    db::UserId,
+    db::{ChannelId, UserId},
     AppState,
 };
 use anyhow::anyhow;
@@ -39,7 +39,7 @@ pub struct State {
 }
 
 struct ConnectionState {
-    _user_id: UserId,
+    user_id: UserId,
     worktrees: HashSet<u64>,
 }
 
@@ -70,11 +70,11 @@ impl WorktreeState {
 
 impl State {
     // Add a new connection associated with a given user.
-    pub fn add_connection(&mut self, connection_id: ConnectionId, _user_id: UserId) {
+    pub fn add_connection(&mut self, connection_id: ConnectionId, user_id: UserId) {
         self.connections.insert(
             connection_id,
             ConnectionState {
-                _user_id,
+                user_id,
                 worktrees: Default::default(),
             },
         );
@@ -130,6 +130,14 @@ impl State {
         }
     }
 
+    fn user_id_for_connection(&self, connection_id: ConnectionId) -> tide::Result<UserId> {
+        Ok(self
+            .connections
+            .get(&connection_id)
+            .ok_or_else(|| anyhow!("unknown connection"))?
+            .user_id)
+    }
+
     fn read_worktree(
         &self,
         worktree_id: u64,
@@ -254,6 +262,8 @@ pub fn add_rpc_routes(router: &mut Router, state: &Arc<AppState>, rpc: &Arc<Peer
     on_message(router, rpc, state, update_buffer);
     on_message(router, rpc, state, buffer_saved);
     on_message(router, rpc, state, save_buffer);
+    on_message(router, rpc, state, get_channels);
+    on_message(router, rpc, state, join_channel);
 }
 
 pub fn add_routes(app: &mut tide::Server<Arc<AppState>>, rpc: &Arc<Peer>) {
@@ -600,6 +610,54 @@ async fn buffer_saved(
     broadcast_in_worktree(request.payload.worktree_id, request, rpc, state).await
 }
 
+async fn get_channels(
+    request: TypedEnvelope<proto::GetChannels>,
+    rpc: &Arc<Peer>,
+    state: &Arc<AppState>,
+) -> tide::Result<()> {
+    let user_id = state
+        .rpc
+        .read()
+        .await
+        .user_id_for_connection(request.sender_id)?;
+    let channels = state.db.get_channels_for_user(user_id).await?;
+    rpc.respond(
+        request.receipt(),
+        proto::GetChannelsResponse {
+            channels: channels
+                .into_iter()
+                .map(|chan| proto::Channel {
+                    id: chan.id().0 as u64,
+                    name: chan.name,
+                })
+                .collect(),
+        },
+    )
+    .await?;
+    Ok(())
+}
+
+async fn join_channel(
+    request: TypedEnvelope<proto::JoinChannel>,
+    rpc: &Arc<Peer>,
+    state: &Arc<AppState>,
+) -> tide::Result<()> {
+    let user_id = state
+        .rpc
+        .read()
+        .await
+        .user_id_for_connection(request.sender_id)?;
+    if !state
+        .db
+        .can_user_access_channel(user_id, ChannelId(request.payload.channel_id as i32))
+        .await?
+    {
+        Err(anyhow!("access denied"))?;
+    }
+
+    Ok(())
+}
+
 async fn broadcast_in_worktree<T: proto::EnvelopedMessage>(
     worktree_id: u64,
     request: TypedEnvelope<T>,
diff --git a/server/src/tests.rs b/server/src/tests.rs
index d0257e9f41..653e2ae59a 100644
--- a/server/src/tests.rs
+++ b/server/src/tests.rs
@@ -1,5 +1,7 @@
 use crate::{
-    auth, db, github,
+    auth,
+    db::{self, UserId},
+    github,
     rpc::{self, add_rpc_routes},
     AppState, Config,
 };
@@ -31,8 +33,8 @@ async fn test_share_worktree(mut cx_a: TestAppContext, mut cx_b: TestAppContext)
 
     // Connect to a server as 2 clients.
     let mut server = TestServer::start().await;
-    let client_a = server.create_client(&mut cx_a, "user_a").await;
-    let client_b = server.create_client(&mut cx_b, "user_b").await;
+    let (_, client_a) = server.create_client(&mut cx_a, "user_a").await;
+    let (_, client_b) = server.create_client(&mut cx_b, "user_b").await;
 
     cx_a.foreground().forbid_parking();
 
@@ -138,9 +140,9 @@ async fn test_propagate_saves_and_fs_changes_in_shared_worktree(
 
     // Connect to a server as 3 clients.
     let mut server = TestServer::start().await;
-    let client_a = server.create_client(&mut cx_a, "user_a").await;
-    let client_b = server.create_client(&mut cx_b, "user_b").await;
-    let client_c = server.create_client(&mut cx_c, "user_c").await;
+    let (_, client_a) = server.create_client(&mut cx_a, "user_a").await;
+    let (_, client_b) = server.create_client(&mut cx_b, "user_b").await;
+    let (_, client_c) = server.create_client(&mut cx_c, "user_c").await;
 
     cx_a.foreground().forbid_parking();
 
@@ -280,8 +282,8 @@ async fn test_buffer_conflict_after_save(mut cx_a: TestAppContext, mut cx_b: Tes
 
     // Connect to a server as 2 clients.
     let mut server = TestServer::start().await;
-    let client_a = server.create_client(&mut cx_a, "user_a").await;
-    let client_b = server.create_client(&mut cx_b, "user_b").await;
+    let (_, client_a) = server.create_client(&mut cx_a, "user_a").await;
+    let (_, client_b) = server.create_client(&mut cx_b, "user_b").await;
 
     cx_a.foreground().forbid_parking();
 
@@ -359,8 +361,8 @@ async fn test_editing_while_guest_opens_buffer(mut cx_a: TestAppContext, mut cx_
 
     // Connect to a server as 2 clients.
     let mut server = TestServer::start().await;
-    let client_a = server.create_client(&mut cx_a, "user_a").await;
-    let client_b = server.create_client(&mut cx_b, "user_b").await;
+    let (_, client_a) = server.create_client(&mut cx_a, "user_a").await;
+    let (_, client_b) = server.create_client(&mut cx_b, "user_b").await;
 
     cx_a.foreground().forbid_parking();
 
@@ -420,8 +422,8 @@ async fn test_peer_disconnection(mut cx_a: TestAppContext, cx_b: TestAppContext)
 
     // Connect to a server as 2 clients.
     let mut server = TestServer::start().await;
-    let client_a = server.create_client(&mut cx_a, "user_a").await;
-    let client_b = server.create_client(&mut cx_a, "user_b").await;
+    let (_, client_a) = server.create_client(&mut cx_a, "user_a").await;
+    let (_, client_b) = server.create_client(&mut cx_a, "user_b").await;
 
     cx_a.foreground().forbid_parking();
 
@@ -474,6 +476,36 @@ async fn test_peer_disconnection(mut cx_a: TestAppContext, cx_b: TestAppContext)
         .await;
 }
 
+#[gpui::test]
+async fn test_basic_chat(mut cx_a: TestAppContext, cx_b: TestAppContext) {
+    let lang_registry = Arc::new(LanguageRegistry::new());
+
+    // Connect to a server as 2 clients.
+    let mut server = TestServer::start().await;
+    let (user_id_a, client_a) = server.create_client(&mut cx_a, "user_a").await;
+    let (user_id_b, client_b) = server.create_client(&mut cx_a, "user_b").await;
+
+    // Create a channel that includes these 2 users and 1 other user.
+    let db = &server.app_state.db;
+    let user_id_c = db.create_user("user_c", false).await.unwrap();
+    let org_id = db.create_org("Test Org", "test-org").await.unwrap();
+    let channel_id = db.create_org_channel(org_id, "test-channel").await.unwrap();
+    db.add_channel_member(channel_id, user_id_a, false)
+        .await
+        .unwrap();
+    db.add_channel_member(channel_id, user_id_b, false)
+        .await
+        .unwrap();
+    db.add_channel_member(channel_id, user_id_c, false)
+        .await
+        .unwrap();
+    db.create_channel_message(channel_id, user_id_c, "first message!")
+        .await
+        .unwrap();
+
+    // let chatroom_a = ChatRoom::
+}
+
 struct TestServer {
     peer: Arc<Peer>,
     app_state: Arc<AppState>,
@@ -497,7 +529,7 @@ impl TestServer {
         }
     }
 
-    async fn create_client(&mut self, cx: &mut TestAppContext, name: &str) -> Client {
+    async fn create_client(&mut self, cx: &mut TestAppContext, name: &str) -> (UserId, Client) {
         let user_id = self.app_state.db.create_user(name, false).await.unwrap();
         let lang_registry = Arc::new(LanguageRegistry::new());
         let client = Client::new(lang_registry.clone());
@@ -520,7 +552,7 @@ impl TestServer {
             .await
             .unwrap();
 
-        client
+        (user_id, client)
     }
 
     async fn build_app_state(db_name: &str) -> Arc<AppState> {
diff --git a/zrpc/src/proto.rs b/zrpc/src/proto.rs
index bb082c1783..77390cbb17 100644
--- a/zrpc/src/proto.rs
+++ b/zrpc/src/proto.rs
@@ -79,6 +79,11 @@ message!(UpdateBuffer);
 request_message!(SaveBuffer, BufferSaved);
 message!(AddPeer);
 message!(RemovePeer);
+request_message!(GetChannels, GetChannelsResponse);
+request_message!(JoinChannel, JoinChannelResponse);
+request_message!(GetUsers, GetUsersResponse);
+message!(SendChannelMessage);
+message!(ChannelMessageSent);
 
 /// A stream of protobuf messages.
 pub struct MessageStream<S> {