Merge pull request #49 from michel/feat/watch-user

feat: watch and unwatch users (WatchUser 5 / UnwatchUser 6)

soulseek-rs-lib/src/actor/server_actor.rs

@@ -18,6 +18,7 @@ use crate::message::server::ReloggedHandler;
 use crate::message::server::SayChatroomHandler;
 use crate::message::server::UserJoinedRoomHandler;
 use crate::message::server::UserLeftRoomHandler;
+use crate::message::server::WatchUserHandler;
 use crate::message::server::WishListIntervalHandler;
 use crate::message::server::{
     GetUserStatsHandler, GetUserStatusHandler, RoomListHandler,
@@ -202,6 +203,17 @@ pub enum ServerMessage {
         status: u32,
         privileged: bool,
     },
+    /// A `WatchUser` (code 5) reply: the initial snapshot for a user we just
+    /// started watching. The stats are absent when the server does not know
+    /// the username.
+    WatchedUserReceived {
+        username: String,
+        exists: bool,
+        status: Option<u32>,
+        average_speed: Option<u32>,
+        shared_files: Option<u32>,
+        shared_folders: Option<u32>,
+    },
     /// A `GetUserStats` (code 36) reply.
     UserStatsReceived {
         username: String,
@@ -359,6 +371,7 @@ impl ServerActor {
         handlers.register_handler(ReloggedHandler);
         handlers.register_handler(RoomListHandler);
         handlers.register_handler(GetUserStatusHandler);
+        handlers.register_handler(WatchUserHandler);
         handlers.register_handler(GetUserStatsHandler);
         handlers.register_handler(JoinRoomHandler);
         handlers.register_handler(LeaveRoomHandler);
@@ -464,6 +477,23 @@ impl ServerActor {
                     privileged,
                 });
             }
+            ServerMessage::WatchedUserReceived {
+                username,
+                exists,
+                status,
+                average_speed,
+                shared_files,
+                shared_folders,
+            } => {
+                self.forward_to_client(ClientOperation::WatchedUserReceived {
+                    username,
+                    exists,
+                    status,
+                    average_speed,
+                    shared_files,
+                    shared_folders,
+                });
+            }
             ServerMessage::UserStatsReceived {
                 username,
                 average_speed,

soulseek-rs-lib/src/client/mod.rs

@@ -245,6 +245,15 @@ pub enum ClientOperation {
         shared_files: u32,
         shared_folders: u32,
     },
+    /// The server answered `WatchUser` for a user we started watching.
+    WatchedUserReceived {
+        username: String,
+        exists: bool,
+        status: Option<u32>,
+        average_speed: Option<u32>,
+        shared_files: Option<u32>,
+        shared_folders: Option<u32>,
+    },
     PeerConnected(String),
     /// A search distributed to us by the server; reply if our shares match.
     IncomingSearch {
@@ -328,6 +337,10 @@ pub struct ClientContext {
     /// What the server has told us about other users, merged across the
     /// separate status and statistics replies.
     user_info: HashMap<String, UserInfo>,
+    /// Users we asked the server to watch (code 5), so it keeps pushing their
+    /// status changes. Kept so a UI can render the watch list and so an
+    /// unwatch can be rejected for someone we never watched.
+    watched_users: HashSet<String>,
     /// Seconds the server wants between wishlist searches (code 104), once it
     /// has told us.
     wishlist_interval: Option<u32>,
@@ -416,6 +429,7 @@ impl ClientContext {
             room_events: Vec::new(),
             room_members: HashMap::new(),
             user_info: HashMap::new(),
+            watched_users: HashSet::new(),
             wishlist_interval: None,
             privileged_users: HashSet::new(),
             own_privileges: None,
@@ -503,6 +517,69 @@ impl ClientContext {
         });
     }
 
+    /// Record that we are now watching `username`.
+    pub fn add_watched_user(&mut self, username: &str) {
+        self.watched_users.insert(username.to_string());
+    }
+
+    /// Forget a watch, dropping any snapshot we held for that user so a later
+    /// re-watch reports a fresh answer rather than a stale one.
+    pub fn remove_watched_user(&mut self, username: &str) {
+        self.watched_users.remove(username);
+        self.user_info.remove(username);
+    }
+
+    /// Everyone we are currently watching, sorted by name.
+    #[must_use]
+    pub fn watched_users(&self) -> Vec<String> {
+        let mut users: Vec<String> =
+            self.watched_users.iter().cloned().collect();
+        users.sort();
+        users
+    }
+
+    /// Record the initial snapshot from a `WatchUser` reply. A username the
+    /// server does not know carries no stats and is dropped from the watch
+    /// list, since the server will never push anything for it.
+    pub fn apply_watched_user(
+        &mut self,
+        username: String,
+        exists: bool,
+        status: Option<u32>,
+        average_speed: Option<u32>,
+        shared_files: Option<u32>,
+        shared_folders: Option<u32>,
+    ) {
+        if !exists {
+            self.watched_users.remove(&username);
+            return;
+        }
+        if let Some(status) = status {
+            let entry = self
+                .user_info
+                .entry(username.clone())
+                .or_insert_with(|| UserInfo::pending(username.clone()));
+            // The watch reply carries no privileged flag, so keep whatever a
+            // previous GetUserStatus told us rather than asserting `false`.
+            let privileged =
+                entry.presence.as_ref().is_some_and(|p| p.privileged);
+            entry.presence = Some(UserPresence {
+                status: UserStatus::from_code(status),
+                privileged,
+            });
+        }
+        if let (Some(average_speed), Some(shared_files), Some(shared_folders)) =
+            (average_speed, shared_files, shared_folders)
+        {
+            self.apply_user_stats(
+                username,
+                average_speed,
+                shared_files,
+                shared_folders,
+            );
+        }
+    }
+
     /// What the server has said about `username` so far.
     #[must_use]
     pub fn user_info(&self, username: &str) -> Option<UserInfo> {

soulseek-rs-lib/src/client/operations.rs

@@ -473,6 +473,26 @@ impl Client {
                             error!("[client] UserStatsReceived write: {}", e);
                         }
                     },
+                    ClientOperation::WatchedUserReceived {
+                        username,
+                        exists,
+                        status,
+                        average_speed,
+                        shared_files,
+                        shared_folders,
+                    } => match client_context.write_safe() {
+                        Ok(mut ctx) => ctx.apply_watched_user(
+                            username,
+                            exists,
+                            status,
+                            average_speed,
+                            shared_files,
+                            shared_folders,
+                        ),
+                        Err(e) => {
+                            error!("[client] WatchedUserReceived write: {}", e);
+                        }
+                    },
                     ClientOperation::RoomEvent(event) => {
                         match client_context.write_safe() {
                             Ok(mut ctx) => ctx.apply_room_event(event),

soulseek-rs-lib/src/client/rooms.rs

@@ -138,6 +138,46 @@ impl Client {
         }
     }
 
+    /// Ask the server to watch `username` (code 5).
+    ///
+    /// The server replies with that user's current status and share
+    /// statistics — readable with [`Client::user_info`] — and then keeps
+    /// pushing their status changes until [`Client::unwatch_user`]. Watching
+    /// a user the server does not know is answered with a "does not exist"
+    /// flag, and that user is dropped from [`Client::watched_users`].
+    ///
+    /// # Errors
+    /// Returns [`SoulseekRs::NotConnected`] if the client is not connected.
+    pub fn watch_user(&self, username: &str) -> Result<()> {
+        use crate::message::server::MessageFactory;
+        self.send_server_message(MessageFactory::build_watch_user(username))?;
+        self.context.write_safe()?.add_watched_user(username);
+        Ok(())
+    }
+
+    /// Stop watching `username` (code 6) and drop what we knew about them.
+    ///
+    /// # Errors
+    /// Returns [`SoulseekRs::NotConnected`] if the client is not connected.
+    pub fn unwatch_user(&self, username: &str) -> Result<()> {
+        use crate::message::server::MessageFactory;
+        self.send_server_message(MessageFactory::build_unwatch_user(username))?;
+        self.context.write_safe()?.remove_watched_user(username);
+        Ok(())
+    }
+
+    /// Everyone this client is currently watching, sorted by name.
+    #[must_use]
+    pub fn watched_users(&self) -> Vec<String> {
+        match self.context.read_safe() {
+            Ok(ctx) => ctx.watched_users(),
+            Err(e) => {
+                error!("[client] watched_users: {}", e);
+                Vec::new()
+            }
+        }
+    }
+
     /// Who is currently in `room`, sorted by name.
     ///
     /// The roster is built from the membership the server sends when

soulseek-rs-lib/src/client/tests.rs

@@ -622,3 +622,83 @@ fn a_replayed_transfer_response_does_not_start_a_second_transfer() {
         "a replayed TransferResponse must not dial the peer again"
     );
 }
+
+#[test]
+fn a_watch_reply_fills_both_halves_of_the_snapshot() {
+    let mut context = ClientContext::new();
+    context.add_watched_user("alice");
+    context.apply_watched_user(
+        "alice".to_string(),
+        true,
+        Some(2),
+        Some(1024),
+        Some(20),
+        Some(3),
+    );
+
+    let info = context.user_info("alice").expect("a snapshot");
+    assert!(info.is_complete(), "a watch reply carries status and stats");
+    assert_eq!(info.stats.map(|s| s.average_speed), Some(1024));
+    assert_eq!(context.watched_users(), vec!["alice".to_string()]);
+}
+
+#[test]
+fn a_watch_reply_keeps_a_privileged_flag_it_cannot_carry() {
+    // WatchUser has no privileged field, so it must not overwrite what
+    // GetUserStatus already told us with a fabricated `false`.
+    let mut context = ClientContext::new();
+    context.apply_user_status("bob".to_string(), 1, true);
+    context.apply_watched_user(
+        "bob".to_string(),
+        true,
+        Some(2),
+        Some(1),
+        Some(2),
+        Some(3),
+    );
+
+    let info = context.user_info("bob").expect("a snapshot");
+    assert_eq!(info.presence.map(|p| p.privileged), Some(true));
+}
+
+#[test]
+fn watching_an_unknown_user_drops_them_from_the_list() {
+    // The server will never push status for a name it does not know, so
+    // keeping it in the watch list would show a permanently blank row.
+    let mut context = ClientContext::new();
+    context.add_watched_user("ghost");
+    context.apply_watched_user(
+        "ghost".to_string(),
+        false,
+        None,
+        None,
+        None,
+        None,
+    );
+
+    assert!(context.watched_users().is_empty());
+    assert!(context.user_info("ghost").is_none());
+}
+
+#[test]
+fn unwatching_forgets_the_users_snapshot() {
+    let mut context = ClientContext::new();
+    context.add_watched_user("alice");
+    context.apply_user_status("alice".to_string(), 2, false);
+
+    context.remove_watched_user("alice");
+    assert!(context.watched_users().is_empty());
+    assert!(
+        context.user_info("alice").is_none(),
+        "a later re-watch must report a fresh answer"
+    );
+}
+
+#[test]
+fn watched_users_are_listed_in_a_stable_order() {
+    let mut context = ClientContext::new();
+    context.add_watched_user("carol");
+    context.add_watched_user("alice");
+    context.add_watched_user("bob");
+    assert_eq!(context.watched_users(), vec!["alice", "bob", "carol"]);
+}

soulseek-rs-lib/src/message/server/message_factory.rs

@@ -152,6 +152,20 @@ impl MessageFactory {
             .clone()
     }
 
+    /// Watch `username` (server code 5): the server replies with their
+    /// current status and share statistics, then pushes every later status
+    /// change as a `GetUserStatus` (code 7) until we unwatch them.
+    #[must_use]
+    pub fn build_watch_user(username: &str) -> Message {
+        Message::new().write_int32(5).write_string(username).clone()
+    }
+
+    /// Stop watching `username` (server code 6). The server sends no reply.
+    #[must_use]
+    pub fn build_unwatch_user(username: &str) -> Message {
+        Message::new().write_int32(6).write_string(username).clone()
+    }
+
     /// Ask the server (code 64) for the list of public chat rooms.
     #[must_use]
     pub fn build_room_list_request() -> Message {
@@ -424,3 +438,17 @@ fn test_build_file_search_message() {
     .to_vec();
     assert_eq!(expect, message.get_data());
 }
+
+#[test]
+fn test_build_watch_user() {
+    let message = MessageFactory::build_watch_user("bob");
+    let expect: Vec<u8> = [5, 0, 0, 0, 3, 0, 0, 0, b'b', b'o', b'b'].to_vec();
+    assert_eq!(expect, message.get_data());
+}
+
+#[test]
+fn test_build_unwatch_user() {
+    let message = MessageFactory::build_unwatch_user("bob");
+    let expect: Vec<u8> = [6, 0, 0, 0, 3, 0, 0, 0, b'b', b'o', b'b'].to_vec();
+    assert_eq!(expect, message.get_data());
+}

soulseek-rs-lib/src/message/server/mod.rs

@@ -16,6 +16,7 @@ mod say_chatroom;
 mod user_info;
 mod user_joined_room;
 mod user_left_room;
+mod watch_user;
 mod wish_list_interval;
 
 pub use connect_to_peer::ConnectToPeerHandler;
@@ -36,4 +37,5 @@ pub use say_chatroom::SayChatroomHandler;
 pub use user_info::{GetUserStatsHandler, GetUserStatusHandler};
 pub use user_joined_room::UserJoinedRoomHandler;
 pub use user_left_room::UserLeftRoomHandler;
+pub use watch_user::WatchUserHandler;
 pub use wish_list_interval::WishListIntervalHandler;

soulseek-rs-lib/src/message/server/watch_user.rs

@@ -0,0 +1,146 @@
+//! `WatchUser` (code 5): subscribe to a user's status and share statistics.
+//!
+//! Watching is how a client keeps a buddy list current. After a `WatchUser`
+//! request the server answers on the same code with the user's current
+//! presence and stats, and from then on pushes every later change as an
+//! ordinary `GetUserStatus` (code 7). `UnwatchUser` (code 6) cancels the
+//! subscription and has no reply.
+//!
+//! Note on codes: the protocol has no `AddUserList`/`WatchedUserAdded`
+//! /`WatchedUserRemoved` messages — 141/142/143 are `EnableRoomInvitations`,
+//! `ChangePassword` and `AddRoomOperator`. Watching is 5/6, per the reference
+//! protocol documentation.
+
+use crate::actor::server_actor::ServerMessage;
+use crate::message::{Message, MessageHandler};
+use std::sync::mpsc::Sender;
+
+/// Receives the `WatchUser` reply (code 5): `username`, `exists`, and — when
+/// the user exists — status plus the same share statistics `GetUserStats`
+/// carries.
+pub struct WatchUserHandler;
+
+impl MessageHandler<ServerMessage> for WatchUserHandler {
+    fn get_code(&self) -> u8 {
+        5
+    }
+
+    fn handle(&self, message: &mut Message, sender: Sender<ServerMessage>) {
+        let username = message.read_string();
+        let exists = message.read_bool();
+        let watched = if exists {
+            let status = message.read_int32();
+            let average_speed = message.read_int32();
+            // Two obsolete 32-bit fields, exactly as GetUserStats (36)
+            // carries them -- not one 64-bit value. The byte count is the
+            // same either way, but reading them as the server writes them
+            // keeps this handler and its sibling honest.
+            let _upload_number = message.read_int32(); // obsolete, always 0
+            let _unknown = message.read_int32(); // obsolete, always 0
+            let shared_files = message.read_int32();
+            let shared_folders = message.read_int32();
+            ServerMessage::WatchedUserReceived {
+                username,
+                exists,
+                status: Some(status),
+                average_speed: Some(average_speed),
+                shared_files: Some(shared_files),
+                shared_folders: Some(shared_folders),
+            }
+        } else {
+            // An unknown username: the server stops after the flag, so there
+            // is nothing further to read and nothing to record.
+            ServerMessage::WatchedUserReceived {
+                username,
+                exists,
+                status: None,
+                average_speed: None,
+                shared_files: None,
+                shared_folders: None,
+            }
+        };
+        let _ = sender.send(watched);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::message::framed;
+
+    #[test]
+    fn existing_user_carries_status_and_stats() {
+        let (tx, rx) = std::sync::mpsc::channel();
+        let mut message = framed(|m| {
+            m.write_string("alice")
+                .write_int8(1) // exists
+                .write_int32(2) // status: online
+                .write_int32(1024) // average speed
+                .write_int32(0) // obsolete upload number
+                .write_int32(0) // obsolete unknown
+                .write_int32(4321) // shared files
+                .write_int32(77); // shared folders
+        });
+
+        WatchUserHandler.handle(&mut message, tx);
+        match rx.try_recv() {
+            Ok(ServerMessage::WatchedUserReceived {
+                username,
+                exists,
+                status,
+                average_speed,
+                shared_files,
+                shared_folders,
+            }) => {
+                assert_eq!(username, "alice");
+                assert!(exists);
+                assert_eq!(status, Some(2));
+                assert_eq!(average_speed, Some(1024));
+                assert_eq!(shared_files, Some(4321));
+                assert_eq!(shared_folders, Some(77));
+            }
+            other => panic!("unexpected: {other:?}"),
+        }
+    }
+
+    #[test]
+    fn unknown_user_reports_absence_without_stats() {
+        let (tx, rx) = std::sync::mpsc::channel();
+        let mut message = framed(|m| {
+            m.write_string("ghost").write_int8(0);
+        });
+
+        WatchUserHandler.handle(&mut message, tx);
+        match rx.try_recv() {
+            Ok(ServerMessage::WatchedUserReceived {
+                username,
+                exists,
+                status,
+                shared_files,
+                ..
+            }) => {
+                assert_eq!(username, "ghost");
+                assert!(!exists);
+                assert_eq!(status, None);
+                assert_eq!(shared_files, None);
+            }
+            other => panic!("unexpected: {other:?}"),
+        }
+    }
+
+    #[test]
+    fn truncated_payload_does_not_panic() {
+        // exists = 1 but the stats were cut off: the bounds-checked readers
+        // must yield zeros rather than panicking on a hostile frame.
+        let (tx, rx) = std::sync::mpsc::channel();
+        let mut message = framed(|m| {
+            m.write_string("alice").write_int8(1).write_int32(2);
+        });
+
+        WatchUserHandler.handle(&mut message, tx);
+        assert!(matches!(
+            rx.try_recv(),
+            Ok(ServerMessage::WatchedUserReceived { .. })
+        ));
+    }
+}

soulseek-rs-lib/tests/e2e.rs

@@ -2622,3 +2622,101 @@ fn a_peer_that_hangs_up_its_control_connection_still_delivers_the_file() {
 
     let _ = std::fs::remove_dir_all(&download_dir);
 }
+
+#[test]
+fn watching_a_user_returns_their_status_and_share_counts() {
+    let server = server_or_skip!();
+
+    // A subject with a known share, so the watch reply's statistics are
+    // checkable rather than merely present.
+    let share_dir = unique_download_dir().join("watch_share");
+    std::fs::create_dir_all(share_dir.join("album")).unwrap();
+    for name in ["one.flac", "two.flac"] {
+        std::fs::write(share_dir.join("album").join(name), b"xxxx").unwrap();
+    }
+    let mut subject = Client::with_settings(ClientSettings {
+        shared_directories: vec![share_dir.display().to_string()],
+        ..server.settings("e2e_watch_subject", "pw")
+    });
+    subject.connect().expect("subject connect");
+    assert!(subject.login().expect("subject login"));
+
+    let mut watcher =
+        Client::with_settings(server.settings("e2e_watch_watcher", "pw"));
+    watcher.connect().expect("watcher connect");
+    assert!(watcher.login().expect("watcher login"));
+
+    // Let the subject's share counts reach the server before watching, so
+    // the reply describes a user it already knows the statistics for.
+    std::thread::sleep(Duration::from_millis(750));
+
+    watcher
+        .watch_user("e2e_watch_subject")
+        .expect("watch the subject");
+    assert_eq!(
+        watcher.watched_users(),
+        vec!["e2e_watch_subject".to_string()]
+    );
+
+    // One reply carries both halves, unlike the two GetUserStatus and
+    // GetUserStats answers request_user_info waits on.
+    let deadline = Instant::now() + Duration::from_secs(15);
+    let mut info = None;
+    while Instant::now() < deadline {
+        match watcher.user_info("e2e_watch_subject") {
+            Some(found) if found.is_complete() => {
+                info = Some(found);
+                break;
+            }
+            _ => std::thread::sleep(Duration::from_millis(100)),
+        }
+    }
+    let info = info.expect("the watch reply should carry status and stats");
+
+    let presence = info.presence.expect("presence should have arrived");
+    assert!(
+        presence.status.is_reachable(),
+        "a logged-in user should not read as offline, got {}",
+        presence.status
+    );
+    let stats = info.stats.expect("stats should have arrived");
+    assert_eq!(
+        stats.shared_files, 2,
+        "the file count must survive the obsolete fields ahead of it"
+    );
+    assert_eq!(stats.shared_folders, 1);
+
+    // Unwatching drops the user and what we knew about them, so a later
+    // re-watch reports a fresh answer rather than this stale one.
+    watcher
+        .unwatch_user("e2e_watch_subject")
+        .expect("unwatch the subject");
+    assert!(watcher.watched_users().is_empty());
+    assert!(watcher.user_info("e2e_watch_subject").is_none());
+}
+
+#[test]
+fn watching_a_user_the_server_does_not_know_reports_their_absence() {
+    let server = server_or_skip!();
+
+    let mut watcher =
+        Client::with_settings(server.settings("e2e_watch_ghost_asker", "pw"));
+    watcher.connect().expect("watcher connect");
+    assert!(watcher.login().expect("watcher login"));
+
+    watcher
+        .watch_user("e2e_watch_nobody_here")
+        .expect("watch an unknown user");
+
+    // The server answers that it has no such user; the watch is dropped
+    // rather than left showing a permanently blank row.
+    let deadline = Instant::now() + Duration::from_secs(10);
+    while Instant::now() < deadline && !watcher.watched_users().is_empty() {
+        std::thread::sleep(Duration::from_millis(100));
+    }
+    assert!(
+        watcher.watched_users().is_empty(),
+        "a username the server does not know must not stay watched"
+    );
+    assert!(watcher.user_info("e2e_watch_nobody_here").is_none());
+}

soulseek-rs/docs/openrpc.json

@@ -1216,6 +1216,21 @@
           "shared_folders"
         ],
         "type": "object"
+      },
+      "Watched": {
+        "description": "Everyone this session is watching, sorted by name.",
+        "properties": {
+          "users": {
+            "items": {
+              "type": "string"
+            },
+            "type": "array"
+          }
+        },
+        "required": [
+          "users"
+        ],
+        "type": "object"
       }
     }
   },
@@ -1875,6 +1890,58 @@
       },
       "summary": "What the server has said about a user so far."
     },
+    {
+      "name": "user.watch",
+      "paramStructure": "by-name",
+      "params": [
+        {
+          "name": "username",
+          "required": true,
+          "schema": {
+            "type": "string"
+          }
+        }
+      ],
+      "result": {
+        "name": "result",
+        "schema": {
+          "$ref": "#/components/schemas/Ack"
+        }
+      },
+      "summary": "Watch a user, so the server keeps pushing their status."
+    },
+    {
+      "name": "user.unwatch",
+      "paramStructure": "by-name",
+      "params": [
+        {
+          "name": "username",
+          "required": true,
+          "schema": {
+            "type": "string"
+          }
+        }
+      ],
+      "result": {
+        "name": "result",
+        "schema": {
+          "$ref": "#/components/schemas/Ack"
+        }
+      },
+      "summary": "Stop watching a user."
+    },
+    {
+      "name": "user.watched",
+      "paramStructure": "by-name",
+      "params": [],
+      "result": {
+        "name": "result",
+        "schema": {
+          "$ref": "#/components/schemas/Watched"
+        }
+      },
+      "summary": "Everyone this session is watching."
+    },
     {
       "name": "shares.status",
       "paramStructure": "by-name",

soulseek-rs/src/SKILL.md

@@ -133,6 +133,13 @@ wishlist later rather than repeating the same search.
 be `null` when the server has not answered that half — `null` means unknown,
 not offline.
 
+**`watch add <user>`** / **`watch remove <user>`** — prints nothing; exit 0 is
+the confirmation. **`watch list`** — one object per watched user: `user`,
+`status`. A watch lasts only as long as the session holding it, so these are
+worth using against a running daemon (`--daemon`), where the connection stays
+up and keeps receiving the server's status pushes. A one-shot run's watch ends
+with the run.
+
 **`whoami`** — one object: `user`, `server`, `listening`, `listen_port`,
 `shared_folders`, `shared_files`, `download_dir`, `privilege_seconds`. The
 cheapest way to prove the credentials and connection work.

soulseek-rs/src/api.rs

@@ -140,6 +140,12 @@ pub trait SessionApi: Send + Sync {
     fn request_user_info(&self, username: &str) -> Result<()>;
     fn user_info(&self, username: &str) -> Option<UserInfo>;
 
+    /// Ask the server to keep pushing `username`'s status until unwatched.
+    fn watch_user(&self, username: &str) -> Result<()>;
+    fn unwatch_user(&self, username: &str) -> Result<()>;
+    /// Everyone this session is watching, sorted by name.
+    fn watched_users(&self) -> Vec<String>;
+
     /// The conversation this session already knows about.
     ///
     /// Empty locally, where the TUI's own snapshot on disk is the record. A
@@ -364,6 +370,18 @@ impl SessionApi for Client {
         Self::user_info(self, username)
     }
 
+    fn watch_user(&self, username: &str) -> Result<()> {
+        Self::watch_user(self, username)
+    }
+
+    fn unwatch_user(&self, username: &str) -> Result<()> {
+        Self::unwatch_user(self, username)
+    }
+
+    fn watched_users(&self) -> Vec<String> {
+        Self::watched_users(self)
+    }
+
     fn shared_counts(&self) -> (u32, u32) {
         Self::shared_counts(self)
     }

soulseek-rs/src/cli.rs

@@ -207,6 +207,10 @@ pub enum Commands {
     /// What the server knows about another user
     User(UserArgs),
 
+    /// Keep a daemon updated about users you care about
+    #[command(subcommand)]
+    Watch(WatchCommand),
+
     /// Confirm the credentials and connection work
     Whoami,
 
@@ -571,6 +575,26 @@ pub struct WishRunArgs {
     pub sort: SortKey,
 }
 
+/// Watching only lasts as long as the session doing it, so these are aimed at
+/// a running daemon: it stays connected and keeps receiving the status pushes.
+#[derive(Subcommand, Debug)]
+pub enum WatchCommand {
+    /// Start watching a user
+    Add {
+        /// The user to watch
+        user: String,
+    },
+
+    /// Stop watching a user
+    Remove {
+        /// The user to stop watching
+        user: String,
+    },
+
+    /// List the users being watched
+    List,
+}
+
 #[derive(Subcommand, Debug)]
 pub enum RoomCommand {
     /// List public rooms and their user counts

soulseek-rs/src/commands/mod.rs

@@ -309,6 +309,7 @@ fn dispatch(ctx: &Ctx, command: Commands) -> CliResult {
             social::message_read(ctx, listen_span(duration, follow))
         }
         Commands::User(args) => peer::user(ctx, &args),
+        Commands::Watch(command) => peer::watch(ctx, &command),
         Commands::Whoami => peer::whoami(ctx),
         // main.rs runs these itself: some need no account, the rest need the
         // config store in scope. The arms only keep the match exhaustive.

soulseek-rs/src/commands/peer.rs

@@ -1,9 +1,10 @@
 //! Being a peer on the network: `serve`, `whoami`, and `user`.
 
 use super::{Ctx, Session};
-use crate::cli::{ServeArgs, UserArgs};
+use crate::cli::{ServeArgs, UserArgs, WatchCommand};
 use crate::output::{
-    CliError, CliResult, UploadRecord, UserRecord, WhoamiRecord,
+    CliError, CliResult, UploadRecord, UserRecord, WatchedUserRecord,
+    WhoamiRecord,
 };
 use soulseek_rs::types::{UploadInfo, UploadStatus, UserInfo};
 use std::collections::HashMap;
@@ -94,6 +95,40 @@ pub fn user(ctx: &Ctx, args: &UserArgs) -> CliResult {
     Ok(())
 }
 
+/// Start or stop watching a user, or list who is being watched.
+///
+/// A watch lives in the session that made it, so `add` against a one-shot CLI
+/// run ends with that run. Pointed at a daemon it persists for that daemon's
+/// lifetime, which is the point of the command.
+pub fn watch(ctx: &Ctx, command: &WatchCommand) -> CliResult {
+    let session = Session::open(ctx)?;
+    match command {
+        WatchCommand::Add { user } => {
+            session.client.watch_user(user).map_err(|e| {
+                CliError::connection(format!("cannot watch {user}: {e}"))
+            })?;
+            ctx.out.status(&format!("watching {user}"));
+        }
+        WatchCommand::Remove { user } => {
+            session.client.unwatch_user(user).map_err(|e| {
+                CliError::connection(format!("cannot unwatch {user}: {e}"))
+            })?;
+            ctx.out.status(&format!("no longer watching {user}"));
+        }
+        WatchCommand::List => {
+            for user in session.client.watched_users() {
+                let status = session
+                    .client
+                    .user_info(&user)
+                    .and_then(|info| info.presence)
+                    .map(|p| p.status.to_string());
+                ctx.out.emit(&WatchedUserRecord { user, status });
+            }
+        }
+    }
+    Ok(())
+}
+
 /// Stay online sharing files, and — with `--wishlist` — re-run the standing
 /// searches on the interval the server sets while doing so.
 pub fn serve(

soulseek-rs/src/daemon/openrpc.rs

@@ -15,6 +15,7 @@ use super::proto::{
     Method, QueryParams, RoomEventDto, RoomRef, SayParams, SearchResults,
     Searches, Seconds, SessionLossEvent, SharesStatus, SlotsParams,
     TransferRef, UploadInfoDto, Uploads, UserMessageDto, UserRef, UserResult,
+    Watched,
 };
 use schemars::{JsonSchema, SchemaGenerator, generate::SchemaSettings};
 use serde_json::{Value, json};
@@ -51,9 +52,11 @@ fn params_schema(method: Method, generator: &mut SchemaGenerator) -> Value {
         }
         Method::RoomSay => schema_of::<SayParams>(generator),
         Method::MessageSend => schema_of::<MessageParams>(generator),
-        Method::BrowseUser | Method::UserRequest | Method::UserInfoOf => {
+        Method::BrowseUser
-            schema_of::<UserRef>(generator)
+        | Method::UserRequest
-        }
+        | Method::UserInfoOf
+        | Method::UserWatch
+        | Method::UserUnwatch => schema_of::<UserRef>(generator),
         Method::SharesSet => schema_of::<DirectoriesParams>(generator),
         // Methods that take no parameters.
         Method::DaemonStatus
@@ -68,7 +71,8 @@ fn params_schema(method: Method, generator: &mut SchemaGenerator) -> Value {
         | Method::MessageHistory
         | Method::SearchList
         | Method::SharesStatusOf
-        | Method::SharesReindex => json!({ "type": "null" }),
+        | Method::SharesReindex
+        | Method::UserWatched => json!({ "type": "null" }),
     }
 }
 
@@ -88,6 +92,7 @@ fn result_schema(method: Method, generator: &mut SchemaGenerator) -> Value {
         Method::UploadList => schema_of::<Uploads>(generator),
         Method::PrivilegesOwn => schema_of::<Seconds>(generator),
         Method::RoomMembers => schema_of::<Members>(generator),
+        Method::UserWatched => schema_of::<Watched>(generator),
         Method::MessageHistory => schema_of::<Messages>(generator),
         Method::UserInfoOf => schema_of::<UserResult>(generator),
         Method::SharesStatusOf | Method::SharesSet | Method::SharesReindex => {
@@ -112,7 +117,9 @@ fn result_schema(method: Method, generator: &mut SchemaGenerator) -> Value {
         | Method::MessageSend
         | Method::BrowseUser
         | Method::SearchForget
-        | Method::UserRequest => schema_of::<Ack>(generator),
+        | Method::UserRequest
+        | Method::UserWatch
+        | Method::UserUnwatch => schema_of::<Ack>(generator),
     }
 }
 
@@ -172,6 +179,11 @@ fn summary(method: Method) -> &'static str {
         Method::RoomLeave => "Leave a chat room.",
         Method::RoomSay => "Post a message to a room.",
         Method::RoomMembers => "Who is currently in a room.",
+        Method::UserWatch => {
+            "Watch a user, so the server keeps pushing their status."
+        }
+        Method::UserUnwatch => "Stop watching a user.",
+        Method::UserWatched => "Everyone this session is watching.",
         Method::MessageSend => "Send a private message.",
         Method::MessageHistory => {
             "Private messages the daemon collected, including while nobody was attached."

soulseek-rs/src/daemon/proto/method.rs

@@ -139,6 +139,13 @@ pub struct Members {
     pub users: Vec<String>,
 }
 
+/// Everyone this session is watching, sorted by name.
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
+#[cfg_attr(test, derive(schemars::JsonSchema))]
+pub struct Watched {
+    pub users: Vec<String>,
+}
+
 /// One line of chat history. Unlike a live [`UserMessageDto`] this carries a
 /// direction, because a conversation the daemon collected includes what this
 /// account sent as well as what it received.

soulseek-rs/src/daemon/proto/mod.rs

@@ -106,6 +106,9 @@ wire_vocabulary! {
         BrowseUser => "browse.user",
         UserRequest => "user.request",
         UserInfoOf => "user.info",
+        UserWatch => "user.watch",
+        UserUnwatch => "user.unwatch",
+        UserWatched => "user.watched",
         SharesStatusOf => "shares.status",
         SharesSet => "shares.set",
         SharesReindex => "shares.reindex",

soulseek-rs/src/daemon/server/mod.rs

@@ -13,7 +13,7 @@ use super::proto::{
     MessageParams, Messages, Method, OPENRPC, PROTOCOL_VERSION, QueryParams,
     RoomRef, RpcError, SayParams, SearchResultDto, SearchResults,
     SearchSummary, Searches, Seconds, SharesStatus, SlotsParams, TransferRef,
-    UploadInfoDto, Uploads, UserInfoDto, UserRef, UserResult,
+    UploadInfoDto, Uploads, UserInfoDto, UserRef, UserResult, Watched,
 };
 use crate::api::SessionApi;
 use crate::output::Exit;
@@ -306,6 +306,24 @@ impl Daemon {
                 })
             }
 
+            Method::UserWatch => {
+                let user: UserRef = parse(params)?;
+                self.session.watch_user(&user.username).map_err(|e| {
+                    RpcError::application(Exit::Connection, e.to_string())
+                })?;
+                ok(Ack::OK)
+            }
+            Method::UserUnwatch => {
+                let user: UserRef = parse(params)?;
+                self.session.unwatch_user(&user.username).map_err(|e| {
+                    RpcError::application(Exit::Connection, e.to_string())
+                })?;
+                ok(Ack::OK)
+            }
+            Method::UserWatched => ok(Watched {
+                users: self.session.watched_users(),
+            }),
+
             Method::SharesStatusOf => ok(self.shares()),
             Method::SharesSet => {
                 let directories: DirectoriesParams = parse(params)?;
@@ -593,6 +611,49 @@ mod tests {
         );
     }
 
+    #[test]
+    fn a_watch_is_readable_back_and_survives_until_unwatched() {
+        // The three methods are only useful together: what `user.watch`
+        // records, `user.watched` must report, and `user.unwatch` must undo.
+        let daemon = daemon_with_token("t");
+        let user = |name: &str| json!({ "username": name });
+
+        daemon
+            .call(Method::UserWatch, user("alice"))
+            .expect("watch");
+        daemon.call(Method::UserWatch, user("bob")).expect("watch");
+        let watched = daemon
+            .call(Method::UserWatched, Value::Null)
+            .expect("watched");
+        assert_eq!(watched["users"], json!(["alice", "bob"]));
+
+        daemon
+            .call(Method::UserUnwatch, user("alice"))
+            .expect("unwatch");
+        let watched = daemon
+            .call(Method::UserWatched, Value::Null)
+            .expect("watched");
+        assert_eq!(
+            watched["users"],
+            json!(["bob"]),
+            "unwatching one must not clear the rest"
+        );
+    }
+
+    #[test]
+    fn watching_the_same_user_twice_lists_them_once() {
+        let daemon = daemon_with_token("t");
+        let alice = json!({ "username": "alice" });
+        daemon
+            .call(Method::UserWatch, alice.clone())
+            .expect("watch");
+        daemon.call(Method::UserWatch, alice).expect("watch");
+        let watched = daemon
+            .call(Method::UserWatched, Value::Null)
+            .expect("watched");
+        assert_eq!(watched["users"], json!(["alice"]));
+    }
+
     #[test]
     fn stop_is_recorded_so_the_daemon_can_wind_down() {
         let daemon = daemon_with_token("t");
@@ -605,11 +666,17 @@ mod tests {
 
     // A session that answers nothing: enough to exercise dispatch, parameter
     // validation, and the auth gate without a Soulseek server.
-    struct SilentSession;
+    /// A session that answers nothing, except that it remembers watches:
+    /// the watch methods are only meaningful if what one call records the
+    /// next call can read back.
+    #[derive(Default)]
+    struct SilentSession {
+        watched: Mutex<Vec<String>>,
+    }
 
     fn daemon_with_token(token: &str) -> Daemon {
         Daemon {
-            session: Arc::new(SilentSession),
+            session: Arc::new(SilentSession::default()),
             hub: Arc::new(Hub::new()),
             browses: Arc::new(PendingBrowses::default()),
             downloads: Arc::new(Mutex::new(Vec::new())),
@@ -792,6 +859,24 @@ mod tests {
         ) -> soulseek_rs::Result<()> {
             Ok(())
         }
+        fn watch_user(&self, username: &str) -> soulseek_rs::Result<()> {
+            let mut watched = self.watched.lock().expect("watch list");
+            if !watched.iter().any(|u| u == username) {
+                watched.push(username.to_string());
+                watched.sort();
+            }
+            Ok(())
+        }
+        fn unwatch_user(&self, username: &str) -> soulseek_rs::Result<()> {
+            self.watched
+                .lock()
+                .expect("watch list")
+                .retain(|u| u != username);
+            Ok(())
+        }
+        fn watched_users(&self) -> Vec<String> {
+            self.watched.lock().expect("watch list").clone()
+        }
         fn user_info(&self, _username: &str) -> Option<soulseek_rs::UserInfo> {
             None
         }

soulseek-rs/src/output.rs

@@ -383,6 +383,25 @@ impl Record for RoomMemberRecord {
     }
 }
 
+/// One user this session is watching, with whatever the server has already
+/// said about them. The status is `None` until the watch reply lands.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize)]
+pub struct WatchedUserRecord {
+    pub user: String,
+    /// `online`, `away`, or `offline`.
+    pub status: Option<String>,
+}
+
+impl Record for WatchedUserRecord {
+    fn text(&self) -> String {
+        format!(
+            "{}\t{}",
+            sanitize(&self.user),
+            self.status.clone().unwrap_or_else(|| "-".to_string())
+        )
+    }
+}
+
 /// One configured share folder.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize)]
 pub struct ShareRecord {

soulseek-rs/src/remote/mod.rs

@@ -15,7 +15,7 @@ use crate::daemon::proto::{
     Members, MessageParams, Messages, Method, PROTOCOL_VERSION, QueryParams,
     Request, Response, RoomRef, RpcError, SayParams, SearchResults, Searches,
     Seconds, SharesStatus, SlotsParams, TransferRef, Uploads, UserRef,
-    UserResult,
+    UserResult, Watched,
 };
 use mirror::Mirror;
 use serde::de::DeserializeOwned;
@@ -757,6 +757,30 @@ impl SessionApi for RemoteSession {
         )
     }
 
+    fn watch_user(&self, username: &str) -> Result<()> {
+        self.tell(
+            Method::UserWatch,
+            UserRef {
+                username: username.to_string(),
+            },
+        )
+    }
+
+    fn unwatch_user(&self, username: &str) -> Result<()> {
+        self.tell(
+            Method::UserUnwatch,
+            UserRef {
+                username: username.to_string(),
+            },
+        )
+    }
+
+    fn watched_users(&self) -> Vec<String> {
+        self.request::<_, Watched>(Method::UserWatched, ())
+            .map(|watched| watched.users)
+            .unwrap_or_default()
+    }
+
     fn user_info(&self, username: &str) -> Option<UserInfo> {
         self.request::<_, UserResult>(
             Method::UserInfoOf,

soulseek-rs/src/ui/main_tui/mod.rs

@@ -489,6 +489,15 @@ mod tests {
         ) -> soulseek_rs::Result<()> {
             Ok(())
         }
+        fn watch_user(&self, _username: &str) -> soulseek_rs::Result<()> {
+            Ok(())
+        }
+        fn unwatch_user(&self, _username: &str) -> soulseek_rs::Result<()> {
+            Ok(())
+        }
+        fn watched_users(&self) -> Vec<String> {
+            Vec::new()
+        }
         fn user_info(&self, _username: &str) -> Option<soulseek_rs::UserInfo> {
             None
         }