Merge W22 shared music listening: release 0.6.0

Personal playlist + per-person timeline-synced shared listening with
gapless prefetch and per-source volume; standalone playlist card in the
3-column layout. Wire bump to gossip v5 (breaking). Version 0.5.1 -> 0.6.0.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,21 @@
 
 All notable changes to PeerSpeak are documented here.
 
+## [0.6.0] — 2026-06-28
+
+### Added
+- **Shared music listening (W22).** A new **Playlist** panel lets you build a personal queue of local audio files and play them on a dedicated music player — Browse to add tracks, play/pause, previous/next, seek, per-track reorder, remove, and a local volume slider, all persisted across sessions. `.pls` and `.m3u` playlists can be imported (remote and non-audio entries are skipped).
+- **Tune in to a friend's music.** Flip **"Let others tune in"** and peers see your current track under the **Public** tab; one click on **Listen** streams it to them. Playback is **timeline-synced** — play, pause, skip, and seek mirror across everyone with no drift — and the next track is **prefetched for gapless** transitions. Each listener gets an independent **per-source volume**, so music sits under voice at whatever level they like; voice chat stays fully audible throughout.
+- **Standalone Playlist card in the 3-Column layout.** The playlist now lives in its own card stacked under the chat, with a draggable divider to resize it and its own scrollbar when space is tight. The other layouts keep the playlist in the Controls panel.
+
+### Security
+- Shared-music metadata is treated as untrusted: the broadcast track name is sanitized and its size is cap-checked at gossip ingest, fetched bytes are confirmed to be audio before decoding, and only a small descriptor ever rides gossip — track bytes move point-to-point over the existing files plane, one fetch in flight at a time.
+
+### Changed
+- **Wire protocol bump (gossip v5).** Shared listening adds presence fields, so **0.6.0 peers cannot share a swarm with 0.5.x peers** — everyone in a room must update together.
+
+[0.6.0]: https://gitbutter.xyz/mollusk/peerspeak/releases/tag/v0.6.0
+
 ## [0.5.1] — 2026-06-27
 
 ### Added

Cargo.lock

@@ -4871,7 +4871,7 @@ checksum = "35fb2e5f958ec131621fdd531e9fc186ed768cbe395337403ae56c17a74c68ec"
 
 [[package]]
 name = "peerspeak"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
  "anyhow",
  "async-trait",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "peerspeak"
-version = "0.5.1"
+version = "0.6.0"
 edition = "2024"
 description = "Decentralized peer-to-peer voice chat (Rust/iroh/PipeWire/Opus/iced)"
 # Application crate, not a crates.io library — refuse `cargo publish` and let

src/bin/test_net.rs

@@ -65,6 +65,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         sharing: None,
         avatar: Default::default(),
         game: None,
+        music: None,
     };
     room_a.join(&ticket_str, state_a, vec![]).await?;
     println!("Node A joined topic.");
@@ -85,6 +86,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         sharing: None,
         avatar: Default::default(),
         game: None,
+        music: None,
     };
     room_b.join(&ticket_str, state_b, vec![]).await?;
     println!("Node B joined topic.");

src/config.rs

@@ -126,6 +126,10 @@ fn default_chat_height() -> f32 {
     180.0
 }
 
+fn default_threecol_playlist_height() -> f32 {
+    220.0
+}
+
 fn default_controls_width() -> f32 {
     280.0
 }
@@ -160,6 +164,16 @@ pub struct AppConfig {
     /// level shared by every uploaded clip so the slider sticks across plays.
     #[serde(default = "default_volume")]
     pub clip_volume: f32,
+    /// W22 music: the user's personal playlist as local file PATHS (not bytes).
+    /// Loaded into memory at startup; missing files are skipped/marked on play.
+    #[serde(default)]
+    pub music_playlist: Vec<String>,
+    /// W22 music: local playback gain for the dedicated music player (1.0 = unity).
+    #[serde(default = "default_volume")]
+    pub music_volume: f32,
+    /// W22 music: opt-in shared listening broadcast toggle. Local preference.
+    #[serde(default)]
+    pub music_broadcast: bool,
     /// When true, `clip_volume` governs every clip. When false, each clip keeps
     /// its own (in-memory) level and the universal slider is inactive.
     #[serde(default = "default_true")]
@@ -182,6 +196,11 @@ pub struct AppConfig {
     pub participants_width: f32,
     #[serde(default = "default_chat_height")]
     pub chat_height: f32,
+    /// Height (px) of the standalone Playlist card stacked under Chat in the
+    /// 3-column layout. Resized via its own horizontal divider; re-clamped to the
+    /// window on load/resize. Only used by `RoomLayout::ThreeColumn`.
+    #[serde(default = "default_threecol_playlist_height")]
+    pub threecol_playlist_height: f32,
     /// Controls panel width for the 3-column layout (px).
     #[serde(default = "default_controls_width")]
     pub controls_width: f32,
@@ -287,6 +306,11 @@ pub struct AppConfig {
     /// string. Local preference only; never sent to peers. Absent entry = unity.
     #[serde(default)]
     pub peer_volume: HashMap<String, f32>,
+    /// Per-source music listen volume/gain (`1.0` = unity), keyed by peer node id
+    /// string. Local preference only; never sent to peers. Absent entry falls
+    /// back to `music_volume`.
+    #[serde(default)]
+    pub music_source_volume: HashMap<String, f32>,
     /// Per-peer listener-side noise-gate threshold (normalized RMS, `0.0` = off),
     /// keyed by peer node id string. Local preference only; never sent to peers.
     /// Absent entry = gate disabled (pass-through).
@@ -321,6 +345,9 @@ impl Default for AppConfig {
             input_volume: 1.0,
             output_volume: 1.0,
             clip_volume: 1.0,
+            music_playlist: Vec::new(),
+            music_volume: 1.0,
+            music_broadcast: false,
             clip_volume_universal: true,
             network_mode: NetworkMode::default(),
             presence_mode: crate::presence::PresenceMode::default(),
@@ -328,6 +355,7 @@ impl Default for AppConfig {
             notifications_enabled: true,
             participants_width: default_participants_width(),
             chat_height: default_chat_height(),
+            threecol_playlist_height: default_threecol_playlist_height(),
             controls_width: default_controls_width(),
             chat_drawer_width: default_chat_drawer_width(),
             room_layout: RoomLayout::default(),
@@ -360,6 +388,7 @@ impl Default for AppConfig {
             peer_eq: HashMap::new(),
             peer_pan: HashMap::new(),
             peer_volume: HashMap::new(),
+            music_source_volume: HashMap::new(),
             peer_gate: HashMap::new(),
             hotkeys: crate::hotkeys::HotkeyMap::default(),
             window_width: default_window_width(),
@@ -516,6 +545,7 @@ mod tests {
         assert!(deserialized.peer_eq.is_empty());
         assert!(deserialized.peer_pan.is_empty());
         assert!(deserialized.peer_volume.is_empty());
+        assert!(deserialized.music_source_volume.is_empty());
         assert!(deserialized.peer_gate.is_empty());
         assert_eq!(
             crate::hotkeys::format_binding(
@@ -668,6 +698,9 @@ mod tests {
         assert_eq!(def.input_volume, 1.0);
         assert_eq!(def.output_volume, 1.0);
         assert_eq!(def.clip_volume, 1.0);
+        assert!(def.music_playlist.is_empty());
+        assert_eq!(def.music_volume, 1.0);
+        assert!(!def.music_broadcast);
         assert!(def.clip_volume_universal);
 
         // Missing in JSON → unity (serde default).
@@ -676,6 +709,9 @@ mod tests {
         assert_eq!(cfg_missing.input_volume, 1.0);
         assert_eq!(cfg_missing.output_volume, 1.0);
         assert_eq!(cfg_missing.clip_volume, 1.0);
+        assert!(cfg_missing.music_playlist.is_empty());
+        assert_eq!(cfg_missing.music_volume, 1.0);
+        assert!(!cfg_missing.music_broadcast);
         // Configs predating the toggle default to universal mode.
         assert!(cfg_missing.clip_volume_universal);
 
@@ -684,6 +720,9 @@ mod tests {
             input_volume: 1.5,
             output_volume: 0.25,
             clip_volume: 0.7,
+            music_playlist: vec!["/tmp/song.ogg".to_string()],
+            music_volume: 0.6,
+            music_broadcast: true,
             clip_volume_universal: false,
             ..AppConfig::default()
         };
@@ -692,6 +731,9 @@ mod tests {
         assert_eq!(round_tripped.input_volume, 1.5);
         assert_eq!(round_tripped.output_volume, 0.25);
         assert_eq!(round_tripped.clip_volume, 0.7);
+        assert_eq!(round_tripped.music_playlist, vec!["/tmp/song.ogg".to_string()]);
+        assert_eq!(round_tripped.music_volume, 0.6);
+        assert!(round_tripped.music_broadcast);
         assert!(!round_tripped.clip_volume_universal);
     }
 

src/core/messages.rs

@@ -61,6 +61,17 @@ pub enum CoreCommand {
     /// (used for on-demand file/chip downloads; images are auto-fetched on
     /// receipt). Replies with `AttachmentReady`/`AttachmentFailed`.
     FetchAttachment { from: EndpointId, attachment: crate::files::ChatAttachment },
+    /// Register `data` as fetchable under `id` for room members (the current
+    /// broadcast track). Called once per track when broadcasting.
+    ServeMusicTrack { id: crate::files::AttachmentId, data: std::sync::Arc<Vec<u8>> },
+    /// Drop a music blob that is no longer current-or-next.
+    ForgetMusicTrack(crate::files::AttachmentId),
+    /// Set (or clear) our broadcast music timeline and re-announce presence.
+    SetMusicPresence(Option<crate::network::MusicPresence>),
+    /// Fetch a source peer's current track bytes after tuning into them.
+    FetchMusic { from: EndpointId, id: crate::files::AttachmentId, size: u64 },
+    /// Fetch a source peer's advertised next track bytes before it becomes current.
+    PrefetchMusic { from: EndpointId, id: crate::files::AttachmentId, size: u64 },
     /// Set the pixelpass binary location (config override, empty = use `$PATH`).
     /// Sent at startup so screen-share can resolve the binary.
     SetPixelpassPath(Option<String>),
@@ -163,6 +174,22 @@ pub fn delivery_class(cmd: &CoreCommand) -> DeliveryClass {
             from: _,
             attachment: _,
         }
+        | CoreCommand::ServeMusicTrack {
+            id: _,
+            data: _,
+        }
+        | CoreCommand::ForgetMusicTrack(_)
+        | CoreCommand::SetMusicPresence(_)
+        | CoreCommand::FetchMusic {
+            from: _,
+            id: _,
+            size: _,
+        }
+        | CoreCommand::PrefetchMusic {
+            from: _,
+            id: _,
+            size: _,
+        }
         | CoreCommand::SetPixelpassPath(_)
         | CoreCommand::ListAudioApps
         | CoreCommand::StartScreenShare { audio_app: _ }
@@ -221,6 +248,12 @@ pub enum UiEvent {
     AttachmentReady { from: EndpointId, id: crate::files::AttachmentId, data: Vec<u8> },
     /// An attachment fetch failed (sender gone, too large, decode error, etc.).
     AttachmentFailed { from: EndpointId, id: crate::files::AttachmentId, error: String },
+    /// A tuned-in source's track bytes arrived; play them in the music sink.
+    MusicReady { from: EndpointId, id: crate::files::AttachmentId, data: Vec<u8> },
+    /// A tuned-in source's next-track bytes arrived; cache them for a gapless swap.
+    MusicPrefetched { from: EndpointId, id: crate::files::AttachmentId, data: Vec<u8> },
+    /// A music-track fetch failed (source gone, too large, etc.).
+    MusicFetchFailed { from: EndpointId, id: crate::files::AttachmentId, error: String },
     /// The apps currently producing audio, for the screen-share audio picker
     /// (A23). Sorted, deduplicated `application.name`s; empty when nothing is
     /// playing or enumeration isn't available. `app_audio_supported` reports

src/core/mod.rs

@@ -865,6 +865,52 @@ fn spawn_attachment_fetch(
     });
 }
 
+fn spawn_music_fetch(
+    transport: Arc<IrohTransport>,
+    ui_tx: mpsc::Sender<UiEvent>,
+    from: EndpointId,
+    id: crate::files::AttachmentId,
+    size: u64,
+) {
+    tokio::spawn(async move {
+        match transport.fetch_blob(from, id, size).await {
+            Ok(data) => {
+                let _ = ui_tx
+                    .send(UiEvent::MusicReady { from, id, data })
+                    .await;
+            }
+            Err(e) => {
+                let _ = ui_tx
+                    .send(UiEvent::MusicFetchFailed { from, id, error: e.to_string() })
+                    .await;
+            }
+        }
+    });
+}
+
+fn spawn_music_prefetch(
+    transport: Arc<IrohTransport>,
+    ui_tx: mpsc::Sender<UiEvent>,
+    from: EndpointId,
+    id: crate::files::AttachmentId,
+    size: u64,
+) {
+    tokio::spawn(async move {
+        match transport.fetch_blob(from, id, size).await {
+            Ok(data) => {
+                let _ = ui_tx
+                    .send(UiEvent::MusicPrefetched { from, id, data })
+                    .await;
+            }
+            Err(e) => {
+                let _ = ui_tx
+                    .send(UiEvent::MusicFetchFailed { from, id, error: e.to_string() })
+                    .await;
+            }
+        }
+    });
+}
+
 /// Finalize and clear the active recording, if any, emitting `RecordingStopped`.
 /// No-op when not recording. Called on stop, room leave, and room switch so a
 /// recording is always closed cleanly (its WAV size fields patched).
@@ -1036,6 +1082,7 @@ async fn run_core_loop(
         name: "Anonymous".to_string(),
         avatar: crate::avatar::Avatar::default(),
         game: None,
+        music: None,
     };
     // Game detection (W17/W18): a background worker polls Steam state + the process
     // list and publishes the debounced running game on a watch channel. Detection
@@ -2665,6 +2712,54 @@ async fn run_core_loop(
                 }
             }
 
+            CoreCommand::ServeMusicTrack { id, data } => {
+                if let Some(session) = &active_session {
+                    session.transport.serve_attachment(id, data);
+                }
+            }
+
+            CoreCommand::ForgetMusicTrack(id) => {
+                if let Some(session) = &active_session {
+                    session.transport.forget_attachment(id);
+                }
+            }
+
+            CoreCommand::SetMusicPresence(music) => {
+                presence.music = music;
+                if let Some(session) = &active_session {
+                    let self_state = presence.to_state(
+                        is_muted.load(Ordering::Relaxed),
+                        net.endpoint.addr(),
+                        current_sharing.clone(),
+                    );
+                    let _ = session.room_state.update_self_state(self_state).await;
+                }
+            }
+
+            CoreCommand::FetchMusic { from, id, size } => {
+                if let Some(session) = &active_session {
+                    spawn_music_fetch(
+                        session.transport.clone(),
+                        ui_tx.clone(),
+                        from,
+                        id,
+                        size,
+                    );
+                }
+            }
+
+            CoreCommand::PrefetchMusic { from, id, size } => {
+                if let Some(session) = &active_session {
+                    spawn_music_prefetch(
+                        session.transport.clone(),
+                        ui_tx.clone(),
+                        from,
+                        id,
+                        size,
+                    );
+                }
+            }
+
             CoreCommand::SetPixelpassPath(path) => {
                 pixelpass_override = path.filter(|p| !p.trim().is_empty());
             }

src/lib.rs

@@ -20,6 +20,7 @@ pub mod recents;
 pub mod discovery;
 pub mod hotkeys;
 pub mod files;
+pub mod playlist;
 pub mod game;
 pub mod widget;
 

src/network/gossip.rs

@@ -645,6 +645,29 @@ impl RoomState for IrohGossipState {
                                             let cleaned = crate::sanitize::sanitize_game_label(&g);
                                             (!cleaned.is_empty()).then_some(cleaned)
                                         });
+                                        // Music presence is untrusted peer data:
+                                        // the track name is display text (sanitize
+                                        // + cap like the game label) and the size
+                                        // bounds a future fetch (reject anything
+                                        // outside the attachment cap).
+                                        state.music = state.music.and_then(|mut m| {
+                                            let name = crate::sanitize::sanitize_game_label(&m.name);
+                                            if name.is_empty() || !crate::files::size_within_cap(m.size) {
+                                                return None;
+                                            }
+                                            m.name = name;
+                                            if m.next_id.is_some() {
+                                                let ok = m
+                                                    .next_size
+                                                    .map(crate::files::size_within_cap)
+                                                    .unwrap_or(false);
+                                                if !ok {
+                                                    m.next_id = None;
+                                                    m.next_size = None;
+                                                }
+                                            }
+                                            Some(m)
+                                        });
                                         // Bound an insider's advertised address set
                                         // before we retain it / hand it to the dialer
                                         // (Tier C F-01).
@@ -959,6 +982,7 @@ mod tests {
             sharing: None,
             avatar: crate::avatar::Avatar::default(),
             game: None,
+            music: None,
         }
     }
 

src/network/iroh_impl.rs

@@ -594,17 +594,21 @@ impl IrohTransport {
         self.shared.served_files.lock().unwrap().insert(id, bytes);
     }
 
-    /// Fetch a chat attachment's bytes from its sender over the file plane. Dials
-    /// the sender on `FILES_ALPN` (preferring a known full address), writes the
-    /// 32-byte id, and reads the response bounded by the descriptor's declared
-    /// size (which the caller has already validated against the global cap). The
-    /// read limit means a malicious sender can't stream us more than advertised.
-    pub async fn fetch_attachment(
+    /// Drop a previously-served blob (e.g. a music track no longer current-or-next).
+    pub fn forget_attachment(&self, id: AttachmentId) {
+        self.shared.served_files.lock().unwrap().remove(&id);
+    }
+
+    /// Fetch `size` bytes stored under `id` from peer `from` over the files plane.
+    /// Shared core of `fetch_attachment` and music-track fetching: dials
+    /// `FILES_ALPN`, writes the 32-byte id, and reads bounded by `size`.
+    pub async fn fetch_blob(
         &self,
         from: EndpointId,
-        att: &ChatAttachment,
+        id: AttachmentId,
+        size: u64,
     ) -> Result<Vec<u8>, NetError> {
-        if !crate::files::size_within_cap(att.size) {
+        if !crate::files::size_within_cap(size) {
             return Err(NetError::Other("attachment size out of range".to_string()));
         }
         let addr = self.shared.addrs.lock().unwrap().get(&from).cloned();
@@ -623,13 +627,13 @@ impl IrohTransport {
             .open_bi()
             .await
             .map_err(|e| NetError::Other(format!("file fetch: open stream failed: {e}")))?;
-        send.write_all(&att.id)
+        send.write_all(&id)
             .await
             .map_err(|e| NetError::Other(format!("file fetch: request write failed: {e}")))?;
         send.finish()
             .map_err(|e| NetError::Other(format!("file fetch: request finish failed: {e}")))?;
 
-        let read = recv.read_to_end(att.size as usize);
+        let read = recv.read_to_end(size as usize);
         let bytes = tokio::time::timeout(FILE_FETCH_TIMEOUT, read)
             .await
             .map_err(|_| NetError::Other("file fetch: read timed out".to_string()))?
@@ -639,6 +643,15 @@ impl IrohTransport {
         }
         Ok(bytes)
     }
+
+    /// Fetch a chat attachment's bytes from its sender over the file plane.
+    pub async fn fetch_attachment(
+        &self,
+        from: EndpointId,
+        att: &ChatAttachment,
+    ) -> Result<Vec<u8>, NetError> {
+        self.fetch_blob(from, att.id, att.size).await
+    }
 }
 
 #[async_trait]

src/network/mod.rs

@@ -22,6 +22,38 @@ pub enum NetError {
     Other(String),
 }
 
+/// A peer's currently-broadcast music track + playback timeline (W22). Rides
+/// gossip presence so listeners can tune in, follow track changes, and keep in
+/// sync. Untrusted like `name`/`game`: the `name` is sanitized and `size` is
+/// cap-checked at gossip ingest. Bytes never ride gossip — they are fetched
+/// point-to-point over the files plane by `id`, exactly like a chat attachment.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct MusicPresence {
+    /// Files-plane handle to fetch this track's bytes (minted per track by the DJ).
+    pub id: crate::files::AttachmentId,
+    /// Sanitized display name (track filename). Untrusted; cleaned at ingest.
+    pub name: String,
+    /// Byte length, bounds the listener's fetch. Must be `<= MAX_ATTACHMENT_BYTES`.
+    pub size: u64,
+    /// True while the DJ has the track paused.
+    pub paused: bool,
+    /// Wall-clock ms (UNIX epoch) of the timeline anchor. While playing, the true
+    /// playhead is `position_ms + (now_ms - anchor_ms)`; while paused it is
+    /// frozen at `position_ms`. Re-stamped on every play/pause/seek.
+    pub anchor_ms: u64,
+    /// Playhead position (ms) at `anchor_ms`.
+    pub position_ms: u64,
+    /// Files-plane handle for the DJ's NEXT track, so listeners can prefetch it
+    /// for a gapless skip. `None` when there is no distinct next track (single
+    /// item playlist) or the DJ isn't ready. Equals a future `id` once that
+    /// track plays.
+    #[serde(default)]
+    pub next_id: Option<crate::files::AttachmentId>,
+    /// Byte length of the next track; bounds the prefetch. Cap-checked at ingest.
+    #[serde(default)]
+    pub next_size: Option<u64>,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
 pub struct PeerState {
     pub name: String,
@@ -48,6 +80,10 @@ pub struct PeerState {
     /// Defaulted so peers/configs predating the field still deserialize.
     #[serde(default)]
     pub game: Option<String>,
+    /// This peer's currently-broadcast music track and playback timeline, or
+    /// `None` when not broadcasting. Defaulted so pre-W22 peers deserialize.
+    #[serde(default)]
+    pub music: Option<MusicPresence>,
 }
 
 /// The locally-owned, "sticky" pieces of our own presence: the identity fields
@@ -70,6 +106,8 @@ pub struct SelfPresence {
     /// (see `crate::sanitize::sanitize_game_label`) before being stored here, so
     /// the outgoing announce carries a safe value.
     pub game: Option<String>,
+    /// Our current broadcast timeline, or `None` when not broadcasting / not playing.
+    pub music: Option<MusicPresence>,
 }
 
 impl SelfPresence {
@@ -89,6 +127,7 @@ impl SelfPresence {
             sharing,
             avatar: self.avatar.clone(),
             game: self.game.clone(),
+            music: self.music.clone(),
         }
     }
 }
@@ -307,6 +346,7 @@ mod tests {
             sharing: None,
             avatar: crate::avatar::Avatar::default(),
             game: None,
+            music: None,
         }
     }
 
@@ -422,6 +462,7 @@ mod tests {
             name: "Alice".to_string(),
             avatar: crate::avatar::Avatar::default(),
             game: Some("Half-Life 2".to_string()),
+            music: None,
         };
         // Volatile fields come from the call; sticky fields from the struct.
         let muted = presence.to_state(true, addr.clone(), Some("ticket".to_string()));
@@ -445,4 +486,21 @@ mod tests {
         let deserialized: PeerState = serde_json::from_str(&serialized).unwrap();
         assert_eq!(original, deserialized);
     }
+
+    #[test]
+    fn music_presence_serde_round_trip() {
+        let original = MusicPresence {
+            id: [3u8; 32],
+            name: "track.ogg".to_string(),
+            size: 1234,
+            paused: false,
+            anchor_ms: 1_700_000_000_000,
+            position_ms: 42_000,
+            next_id: None,
+            next_size: None,
+        };
+        let serialized = serde_json::to_string(&original).unwrap();
+        let deserialized: MusicPresence = serde_json::from_str(&serialized).unwrap();
+        assert_eq!(original, deserialized);
+    }
 }

src/playlist.rs

@@ -0,0 +1,114 @@
+use std::path::{Path, PathBuf};
+
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub enum PlaylistKind {
+    M3u,
+    Pls,
+}
+
+/// Classify a path by extension into a playlist kind, or None if it is not a
+/// recognized playlist file. Case-insensitive: m3u/m3u8 -> M3u, pls -> Pls.
+pub fn playlist_kind(path: &Path) -> Option<PlaylistKind> {
+    let ext = path.extension()?.to_string_lossy();
+    match ext.to_ascii_lowercase().as_str() {
+        "m3u" | "m3u8" => Some(PlaylistKind::M3u),
+        "pls" => Some(PlaylistKind::Pls),
+        _ => None,
+    }
+}
+
+/// Parse an m3u/m3u8 or pls playlist into local audio file paths. Remote entries
+/// (http/https/ftp URLs) and non-audio entries are skipped; relative paths are
+/// resolved against `base_dir` (the playlist file's parent directory). Order is
+/// preserved. Does not touch the filesystem.
+pub fn parse_playlist(contents: &str, base_dir: &Path, kind: PlaylistKind) -> Vec<PathBuf> {
+    let entries: Vec<&str> = match kind {
+        PlaylistKind::M3u => contents
+            .lines()
+            .map(str::trim)
+            .filter(|line| !line.is_empty() && !line.starts_with('#'))
+            .collect(),
+        PlaylistKind::Pls => contents
+            .lines()
+            .filter_map(|line| {
+                let (key, value) = line.split_once('=')?;
+                key.trim()
+                    .to_ascii_lowercase()
+                    .starts_with("file")
+                    .then_some(value.trim())
+            })
+            .filter(|line| !line.is_empty())
+            .collect(),
+    };
+
+    entries
+        .into_iter()
+        .filter_map(|entry| playlist_entry_path(entry, base_dir))
+        .collect()
+}
+
+fn playlist_entry_path(entry: &str, base_dir: &Path) -> Option<PathBuf> {
+    let lower = entry.to_ascii_lowercase();
+    if lower.starts_with("http://")
+        || lower.starts_with("https://")
+        || lower.starts_with("ftp://")
+    {
+        return None;
+    }
+
+    let path = Path::new(entry);
+    let resolved = if path.is_absolute() {
+        path.to_path_buf()
+    } else {
+        base_dir.join(path)
+    };
+    let file_name = resolved.file_name()?.to_string_lossy();
+    crate::files::looks_like_audio_name(&file_name).then_some(resolved)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn m3u_skips_comments_and_remote_urls() {
+        let base = Path::new("/music/lists");
+        let contents = "\
+#EXTM3U
+#EXTINF:123,Artist - Song
+tracks/song.ogg
+https://example.com/stream.mp3
+";
+        assert_eq!(
+            parse_playlist(contents, base, PlaylistKind::M3u),
+            vec![PathBuf::from("/music/lists/tracks/song.ogg")]
+        );
+    }
+
+    #[test]
+    fn pls_keeps_file_values_and_skips_non_audio() {
+        let base = Path::new("/music");
+        let contents = "\
+[playlist]
+File1=one.flac
+Title1=One
+File2=notes.txt
+File3=/var/audio/two.MP3
+";
+        assert_eq!(
+            parse_playlist(contents, base, PlaylistKind::Pls),
+            vec![
+                PathBuf::from("/music/one.flac"),
+                PathBuf::from("/var/audio/two.MP3"),
+            ]
+        );
+    }
+
+    #[test]
+    fn playlist_kind_is_case_insensitive() {
+        assert_eq!(playlist_kind(Path::new("mix.M3U")), Some(PlaylistKind::M3u));
+        assert_eq!(playlist_kind(Path::new("mix.m3u8")), Some(PlaylistKind::M3u));
+        assert_eq!(playlist_kind(Path::new("mix.PLS")), Some(PlaylistKind::Pls));
+        assert_eq!(playlist_kind(Path::new("mix.txt")), None);
+    }
+}

src/protocol.rs

@@ -32,7 +32,14 @@ pub const FRIENDS_PROTO: u32 = 1;
 /// strictly required for decoding — but per the versioning discipline a wire-shape
 /// change is isolated into its own topic + signature domain so v2 and v3 peers
 /// never share a swarm. Resync everyone, exactly like the W4 avatar bump.
-pub const GOSSIP_PROTO: u32 = 3;
+///
+/// v4 (0.6.0): `PeerState` gained an optional `music` presence field carrying a
+/// current shared-listening track descriptor and playback timeline. Bytes still
+/// ride the files plane by id; gossip carries only the descriptor/timeline.
+///
+/// v5 (0.7.0): `MusicPresence` gained optional prefetch hints for the next
+/// track so tuned-in listeners can fetch it before the DJ advances.
+pub const GOSSIP_PROTO: u32 = 5;
 /// File-transfer plane version (chat attachment request/stream shape). Bump on
 /// any change. Mirrored in [`FILES_ALPN`].
 pub const FILES_PROTO: u32 = 1;
@@ -47,7 +54,7 @@ pub const FILES_ALPN: &[u8] = b"peerspeak/files/1";
 /// ed25519 gossip signature domain: `peerspeak-gossip-v<GOSSIP_PROTO>`. Carries
 /// the gossip protocol version into every signed payload — a version mismatch
 /// fails verification (cryptographic separation between gossip versions).
-pub const GOSSIP_SIG_DOMAIN: &str = "peerspeak-gossip-v3";
+pub const GOSSIP_SIG_DOMAIN: &str = "peerspeak-gossip-v5";
 
 /// Version-namespace a room topic so peers on different gossip protocol versions
 /// derive **different subscription topics from the same ticket** and therefore

tests/gossip_rebootstrap.rs

@@ -64,6 +64,7 @@ fn state(name: &str, addr: EndpointAddr) -> PeerState {
         sharing: None,
         avatar: Default::default(),
         game: None,
+        music: None,
     }
 }