Fixed invite logic to be lightweight

.gitignore

@@ -2,3 +2,4 @@
 /nul
 /.claude
 /media
+/federation

Cargo.toml

@@ -1,18 +1,24 @@
 [package]
 name = "furumusic"
-version = "0.4.2"
+version = "0.9.8"
 edition = "2024"
 description = "Reusable web-app boilerplate: auth, OIDC/SSO, admin panel, user management, i18n, PostgreSQL"
 
 [dependencies]
-cot = { version = "0.6.0", features = ["postgres", "json", "openapi", "swagger-ui"] }
+# default-features off: cot's defaults include the sqlite backend, whose old
+# libsqlite3-sys collides with music-dht's rusqlite (one native sqlite3 per
+# binary). This server only ever talks PostgreSQL.
+cot = { version = "0.6.0", default-features = false, features = ["postgres", "json", "openapi", "swagger-ui"] }
 schemars = { version = "0.9", features = ["derive"] }
 serde = { version = "1", features = ["derive"] }
 openidconnect = "4.0"
 reqwest = { version = "0.12", default-features = false, features = ["rustls-tls", "json"] }
 tokio = { version = "1", features = ["sync", "fs", "io-util"] }
+async-stream = "0.3"
+bytes = "1"
 tower = "0.5"
 base64 = "0.22"
+blake3 = "1"
 serde_json = "1"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
@@ -28,5 +34,9 @@ anyhow = "1.0"
 tokio-cron-scheduler = "0.15"
 croner = "3"
 async-trait = "0.1"
+postcard = { version = "1", features = ["alloc"] }
 uuid = "1"
 librqbit = { version = "8.1.1", features = ["disable-upload"] }
+# P2P federation: publishes the library into a shared DHT and serves audio /
+# catalogs to furumi peers (TUI clients) over the frid stack.
+music-dht = "0.3"

src/admin/mod.rs

@@ -415,6 +415,38 @@ impl App for AdminApp {
                 }),
                 "admin_v2_settings_probe",
             ),
+            Route::with_handler_and_name(
+                "/v2/api/federation",
+                get(move |session: Session, db: Database| async move {
+                    v2::federation_status(session, db).await
+                }),
+                "admin_v2_federation_status",
+            ),
+            Route::with_handler_and_name(
+                "/v2/api/federation/sync",
+                cot::router::method::post(move |session: Session, db: Database| async move {
+                    v2::federation_sync(session, db).await
+                }),
+                "admin_v2_federation_sync",
+            ),
+            Route::with_handler_and_name(
+                "/v2/api/federation/ticket",
+                get(move |session: Session, db: Database| async move {
+                    v2::federation_ticket(session, db).await
+                }),
+                "admin_v2_federation_ticket",
+            ),
+            Route::with_handler_and_name(
+                "/v2/api/federation/connect",
+                cot::router::method::post(
+                    move |session: Session,
+                          db: Database,
+                          json: Json<v2::FederationConnectRequest>| async move {
+                        v2::federation_connect(session, db, json).await
+                    },
+                ),
+                "admin_v2_federation_connect",
+            ),
             Route::with_handler_and_name(
                 "/v2/api/jobs/{name}/toggle",
                 cot::router::method::post({
@@ -555,6 +587,32 @@ impl App for AdminApp {
                 },
                 "admin_v2_library_item_detail",
             ),
+            Route::with_handler_and_name(
+                "/v2/api/library/tracks/search",
+                {
+                    let pool = Arc::clone(&pool);
+                    let pool_config = Arc::clone(&pool_config);
+                    get(move |session: Session,
+                              db: Database,
+                              query: UrlQuery<v2::TrackSearchQuery>| {
+                        let pool = Arc::clone(&pool);
+                        let pool_config = Arc::clone(&pool_config);
+                        async move {
+                            let pg_pool = pool
+                                .get_or_init(|| async {
+                                    sqlx::postgres::PgPoolOptions::new()
+                                        .max_connections(5)
+                                        .connect(&pool_config.database_url)
+                                        .await
+                                        .expect("admin pool")
+                                })
+                                .await;
+                            v2::track_search(session, db, pg_pool, query.0).await
+                        }
+                    })
+                },
+                "admin_v2_library_tracks_search",
+            ),
             Route::with_handler_and_name(
                 "/v2/api/library/item/image",
                 {

src/admin/v2.rs

@@ -110,6 +110,7 @@ pub(super) struct UpdateLibraryItemRequest {
     #[serde(default, deserialize_with = "deserialize_optional_stringish")]
     disc_number: Option<String>,
     artist_ids: Option<Vec<i64>>,
+    release_tracks: Option<Vec<ReleaseTrackUpdateRequest>>,
 }
 
 #[derive(Debug, Deserialize)]
@@ -118,6 +119,21 @@ pub(super) struct LibraryItemDetailQuery {
     id: i64,
 }
 
+#[derive(Debug, Deserialize)]
+pub(super) struct TrackSearchQuery {
+    search: Option<String>,
+    limit: Option<i64>,
+}
+
+#[derive(Debug, Deserialize)]
+struct ReleaseTrackUpdateRequest {
+    id: i64,
+    #[serde(default, deserialize_with = "deserialize_optional_stringish")]
+    track_number: Option<String>,
+    #[serde(default, deserialize_with = "deserialize_optional_stringish")]
+    disc_number: Option<String>,
+}
+
 #[derive(Debug, Deserialize)]
 pub(super) struct SetLibraryImageRequest {
     kind: String,
@@ -432,6 +448,12 @@ struct AdminSettingsValues {
     agent_confidence_threshold: String,
     agent_context_limit: String,
     agent_concurrency: String,
+    #[serde(default)]
+    federation_enabled: bool,
+    #[serde(default)]
+    federation_network_id: String,
+    #[serde(default)]
+    federation_save_on_listen: bool,
 }
 
 #[derive(Debug, Clone, Serialize, JsonSchema)]
@@ -456,6 +478,9 @@ struct AdminSettingsSources {
     agent_confidence_threshold: &'static str,
     agent_context_limit: &'static str,
     agent_concurrency: &'static str,
+    federation_enabled: &'static str,
+    federation_network_id: &'static str,
+    federation_save_on_listen: &'static str,
 }
 
 #[derive(Debug, Deserialize)]
@@ -480,6 +505,12 @@ pub(super) struct UpdateSettingsRequest {
     agent_confidence_threshold: String,
     agent_context_limit: String,
     agent_concurrency: String,
+    #[serde(default)]
+    federation_enabled: bool,
+    #[serde(default)]
+    federation_network_id: String,
+    #[serde(default)]
+    federation_save_on_listen: bool,
 }
 
 #[derive(Debug, Serialize, JsonSchema)]
@@ -538,6 +569,7 @@ struct LibraryItemDetailDto {
     selected_artist_ids: Vec<i64>,
     artists: Vec<ArtistOptionDto>,
     releases: Vec<ReleaseOptionDto>,
+    release_tracks: Vec<ReleaseTrackDto>,
     available_covers: Vec<AvailableCoverDto>,
     metadata_tags: Vec<MetadataTagDto>,
 }
@@ -555,6 +587,19 @@ struct ReleaseOptionDto {
     subtitle: String,
 }
 
+#[derive(Debug, Serialize, JsonSchema)]
+struct ReleaseTrackDto {
+    id: i64,
+    title: String,
+    artists: String,
+    release_id: Option<i64>,
+    release_title: Option<String>,
+    track_number: Option<i32>,
+    disc_number: Option<i32>,
+    duration_seconds: f64,
+    is_hidden: bool,
+}
+
 #[derive(Debug, Serialize, JsonSchema)]
 struct AvailableCoverDto {
     media_file_id: i64,
@@ -651,6 +696,19 @@ struct LibraryItemRow {
     updated_at: Option<String>,
 }
 
+#[derive(Debug, sqlx::FromRow)]
+struct ReleaseTrackRow {
+    id: i64,
+    title: String,
+    artists: String,
+    release_id: Option<i64>,
+    release_title: Option<String>,
+    track_number: Option<i32>,
+    disc_number: Option<i32>,
+    duration_seconds: f64,
+    is_hidden: bool,
+}
+
 pub async fn page(admin: AuthenticatedUser, i18n: I18n) -> cot::Result<Html> {
     let template = AdminV2Template {
         t: i18n.t,
@@ -935,6 +993,15 @@ pub async fn update_settings(
             "agent_concurrency",
             body.agent_concurrency.trim().to_string(),
         ),
+        ("federation_enabled", body.federation_enabled.to_string()),
+        (
+            "federation_network_id",
+            body.federation_network_id.trim().to_string(),
+        ),
+        (
+            "federation_save_on_listen",
+            body.federation_save_on_listen.to_string(),
+        ),
     ];
     for (key, value) in fields {
         let mut entry = ConfigEntry::new(key.to_string(), value);
@@ -943,9 +1010,78 @@ pub async fn update_settings(
             .await
             .map_err(|e| cot::Error::internal(e.to_string()))?;
     }
+    // Federation applies on the fly: (re)start or stop the node to match
+    // the freshly saved settings — no server restart involved.
+    let (fresh, _) = AppConfig::load_with_db(&db).await;
+    tokio::spawn(async move {
+        crate::federation::handle().apply(&fresh).await;
+    });
     Json(serde_json::json!({ "ok": true })).into_response()
 }
 
+// ---------------------------------------------------------------------------
+// Federation (status + manual controls)
+// ---------------------------------------------------------------------------
+
+pub async fn federation_status(
+    session: Session,
+    db: Database,
+) -> cot::Result<cot::response::Response> {
+    if let Err(response) = require_admin_json(&session, &db).await {
+        return Ok(response);
+    }
+    Json(crate::federation::handle().status().await).into_response()
+}
+
+pub async fn federation_sync(
+    session: Session,
+    db: Database,
+) -> cot::Result<cot::response::Response> {
+    if let Err(response) = require_admin_json(&session, &db).await {
+        return Ok(response);
+    }
+    let fed = crate::federation::handle();
+    if let Err(err) = fed.sync_now().await {
+        return Ok(json_error(
+            StatusCode::BAD_REQUEST,
+            &format!("sync failed: {err:#}"),
+        ));
+    }
+    Json(fed.status().await).into_response()
+}
+
+pub async fn federation_ticket(
+    session: Session,
+    db: Database,
+) -> cot::Result<cot::response::Response> {
+    if let Err(response) = require_admin_json(&session, &db).await {
+        return Ok(response);
+    }
+    match crate::federation::handle().ticket().await {
+        Ok(ticket) => Json(serde_json::json!({ "ticket": ticket })).into_response(),
+        Err(err) => Ok(json_error(StatusCode::BAD_REQUEST, &format!("{err:#}"))),
+    }
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FederationConnectRequest {
+    ticket: String,
+}
+
+pub async fn federation_connect(
+    session: Session,
+    db: Database,
+    Json(body): Json<FederationConnectRequest>,
+) -> cot::Result<cot::response::Response> {
+    if let Err(response) = require_admin_json(&session, &db).await {
+        return Ok(response);
+    }
+    match crate::federation::handle().connect(&body.ticket).await {
+        Ok(peer) => Json(serde_json::json!({ "connected": peer })).into_response(),
+        Err(err) => Ok(json_error(StatusCode::BAD_REQUEST, &format!("{err:#}"))),
+    }
+}
+
 pub async fn settings_probe(
     session: Session,
     db: Database,
@@ -1014,6 +1150,9 @@ fn settings_dto(config: AppConfig, sources: ConfigSources) -> AdminSettingsDto {
             agent_confidence_threshold: config.agent_confidence_threshold.to_string(),
             agent_context_limit: config.agent_context_limit.to_string(),
             agent_concurrency: config.agent_concurrency.to_string(),
+            federation_enabled: config.federation_enabled,
+            federation_network_id: config.federation_network_id,
+            federation_save_on_listen: config.federation_save_on_listen,
         },
         sources: AdminSettingsSources {
             auth_password_enabled: sources.auth_password_enabled.code(),
@@ -1036,6 +1175,9 @@ fn settings_dto(config: AppConfig, sources: ConfigSources) -> AdminSettingsDto {
             agent_confidence_threshold: sources.agent_confidence_threshold.code(),
             agent_context_limit: sources.agent_context_limit.code(),
             agent_concurrency: sources.agent_concurrency.code(),
+            federation_enabled: sources.federation_enabled.code(),
+            federation_network_id: sources.federation_network_id.code(),
+            federation_save_on_listen: sources.federation_save_on_listen.code(),
         },
     }
 }
@@ -1289,6 +1431,21 @@ pub async fn library_item_detail(
         return Ok(response);
     }
     let kind = normalize_library_kind(Some(query.kind.as_str()));
+    if kind == "releases" && query.id == 0 {
+        let item = LibraryItemDto {
+            id: 0,
+            kind: kind.clone(),
+            title: String::new(),
+            subtitle: String::new(),
+            is_hidden: Some(false),
+            tags: Vec::new(),
+            updated_at: None,
+        };
+        let detail = load_library_item_detail(pool, &kind, item)
+            .await
+            .map_err(|e| cot::Error::internal(e.to_string()))?;
+        return Json(detail).into_response();
+    }
     let Some(item) = fetch_library_item(pool, &kind, query.id)
         .await
         .map_err(|e| cot::Error::internal(e.to_string()))?
@@ -1301,6 +1458,25 @@ pub async fn library_item_detail(
     Json(detail).into_response()
 }
 
+pub async fn track_search(
+    session: Session,
+    db: Database,
+    pool: &PgPool,
+    query: TrackSearchQuery,
+) -> cot::Result<cot::response::Response> {
+    if let Err(response) = require_admin_json(&session, &db).await {
+        return Ok(response);
+    }
+
+    let Some(search) = clean_search(query.search.as_deref()) else {
+        return Json(Vec::<ReleaseTrackDto>::new()).into_response();
+    };
+    let tracks = search_tracks(pool, &search, query.limit.unwrap_or(16).clamp(1, 40))
+        .await
+        .map_err(|e| cot::Error::internal(e.to_string()))?;
+    Json(tracks).into_response()
+}
+
 pub async fn update_library_item(
     session: Session,
     db: Database,
@@ -1318,6 +1494,19 @@ pub async fn update_library_item(
     }
 
     let now = now_string();
+    if kind == "releases" && body.id == 0 {
+        let release_id = create_release_library_item(pool, &body, title, &now)
+            .await
+            .map_err(|e| cot::Error::internal(e.to_string()))?;
+        let Some(item) = fetch_library_item(pool, &kind, release_id)
+            .await
+            .map_err(|e| cot::Error::internal(e.to_string()))?
+        else {
+            return Ok(json_error(StatusCode::NOT_FOUND, "library item not found"));
+        };
+        return Json(item).into_response();
+    }
+
     let affected = match kind.as_str() {
         "artists" => {
             sqlx::query(
@@ -1421,22 +1610,9 @@ pub async fn update_library_item(
             let mut seen_artist_ids = HashSet::new();
             artist_ids.retain(|id| *id > 0 && seen_artist_ids.insert(*id));
             if kind == "releases" {
-                sqlx::query("DELETE FROM furumusic__release_artist WHERE release_id = $1")
-                    .bind(body.id)
-                    .execute(pool)
+                set_release_artists(pool, body.id, &artist_ids)
                     .await
                     .map_err(|e| cot::Error::internal(e.to_string()))?;
-                for (position, artist_id) in artist_ids.iter().enumerate() {
-                    sqlx::query(
-                        "INSERT INTO furumusic__release_artist (release_id, artist_id, position) VALUES ($1, $2, $3)",
-                    )
-                    .bind(body.id)
-                    .bind(*artist_id)
-                    .bind(position as i32)
-                    .execute(pool)
-                    .await
-                    .map_err(|e| cot::Error::internal(e.to_string()))?;
-                }
             } else {
                 sqlx::query(
                     "DELETE FROM furumusic__track_artist WHERE track_id = $1 AND role = 'main'",
@@ -1460,6 +1636,14 @@ pub async fn update_library_item(
         }
     }
 
+    if kind == "releases" {
+        if let Some(release_tracks) = body.release_tracks.as_deref() {
+            update_release_tracks(pool, body.id, release_tracks, &now)
+                .await
+                .map_err(|e| cot::Error::internal(e.to_string()))?;
+        }
+    }
+
     let Some(item) = fetch_library_item(pool, &kind, body.id)
         .await
         .map_err(|e| cot::Error::internal(e.to_string()))?
@@ -2647,13 +2831,13 @@ async fn fetch_library_item(
         "tracks" => {
             sqlx::query_as::<_, LibraryItemRow>(
                 "SELECT t.id, t.title::text AS title, \
-                        CONCAT(r.title::text, COALESCE(' / #' || t.track_number::text, '')) AS subtitle, \
+                        CONCAT(COALESCE(r.title::text, 'No release'), COALESCE(' / #' || t.track_number::text, '')) AS subtitle, \
                         t.is_hidden, COUNT(DISTINCT ta.artist_id)::bigint AS primary_count, \
                         COUNT(DISTINCT ph.id)::bigint AS secondary_count, \
                         COUNT(DISTINCT pt.playlist_id)::bigint AS tertiary_count, \
                         t.updated_at::text AS updated_at \
                  FROM furumusic__track t \
-                 JOIN furumusic__release r ON r.id = t.release_id \
+                 LEFT JOIN furumusic__release r ON r.id = t.release_id \
                  LEFT JOIN furumusic__track_artist ta ON ta.track_id = t.id \
                  LEFT JOIN furumusic__play_history ph ON ph.track_id = t.id \
                  LEFT JOIN furumusic__playlist_track pt ON pt.track_id = t.id \
@@ -2704,6 +2888,7 @@ async fn load_library_item_detail(
         selected_artist_ids: Vec::new(),
         artists: Vec::new(),
         releases: Vec::new(),
+        release_tracks: Vec::new(),
         available_covers: Vec::new(),
         metadata_tags: load_metadata_tags(pool, kind, item.id).await?,
         item,
@@ -2744,16 +2929,22 @@ async fn load_library_item_detail(
             .map(|row| row.id)
             .collect();
             detail.artists = load_artist_options(pool).await?;
+            if detail.item.id > 0 {
+                detail.release_tracks = load_release_tracks(pool, detail.item.id).await?;
+            }
         }
         "tracks" => {
-            let row: Option<(i64, Option<i32>, Option<i32>, Option<i32>)> = sqlx::query_as(
-                "SELECT release_id, track_number, disc_number, year FROM furumusic__track WHERE id = $1",
+            let row: Option<(Option<i64>, Option<i32>, Option<i32>, Option<i32>)> = sqlx::query_as(
+                "SELECT r.id AS release_id, t.track_number, t.disc_number, t.year \
+                 FROM furumusic__track t \
+                 LEFT JOIN furumusic__release r ON r.id = t.release_id \
+                 WHERE t.id = $1",
             )
             .bind(detail.item.id)
             .fetch_optional(pool)
             .await?;
             if let Some((release_id, track_number, disc_number, year)) = row {
-                detail.release_id = Some(release_id);
+                detail.release_id = release_id;
                 detail.track_number = track_number;
                 detail.disc_number = disc_number;
                 detail.year = year;
@@ -2901,6 +3092,210 @@ async fn load_release_options(pool: &PgPool) -> anyhow::Result<Vec<ReleaseOption
         .collect())
 }
 
+async fn create_release_library_item(
+    pool: &PgPool,
+    body: &UpdateLibraryItemRequest,
+    title: &str,
+    now: &str,
+) -> anyhow::Result<i64> {
+    let release_type = body
+        .release_type
+        .as_deref()
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .unwrap_or("album");
+    let year = body
+        .year
+        .as_deref()
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .and_then(|value| value.parse::<i32>().ok());
+    let release_id: i64 = sqlx::query_scalar(
+        "INSERT INTO furumusic__release \
+           (title, title_sort, release_type, year, cover_file_id, total_tracks, total_discs, is_hidden, model_name, created_at, updated_at) \
+         VALUES ($1, $2, $3, $4, NULL, NULL, NULL, $5, NULL, $6, $6) \
+         RETURNING id",
+    )
+    .bind(title)
+    .bind(normalize_name(title))
+    .bind(release_type)
+    .bind(year)
+    .bind(body.hidden)
+    .bind(now)
+    .fetch_one(pool)
+    .await?;
+
+    if let Some(artist_ids) = body.artist_ids.as_deref() {
+        set_release_artists(pool, release_id, artist_ids).await?;
+    }
+    if let Some(release_tracks) = body.release_tracks.as_deref() {
+        update_release_tracks(pool, release_id, release_tracks, now).await?;
+    }
+
+    Ok(release_id)
+}
+
+async fn set_release_artists(
+    pool: &PgPool,
+    release_id: i64,
+    artist_ids: &[i64],
+) -> anyhow::Result<()> {
+    sqlx::query("DELETE FROM furumusic__release_artist WHERE release_id = $1")
+        .bind(release_id)
+        .execute(pool)
+        .await?;
+
+    let mut seen_artist_ids = HashSet::new();
+    let unique_artist_ids = artist_ids
+        .iter()
+        .copied()
+        .filter(|id| *id > 0 && seen_artist_ids.insert(*id))
+        .collect::<Vec<_>>();
+
+    for (position, artist_id) in unique_artist_ids.iter().enumerate() {
+        sqlx::query(
+            "INSERT INTO furumusic__release_artist (release_id, artist_id, position) VALUES ($1, $2, $3)",
+        )
+        .bind(release_id)
+        .bind(*artist_id)
+        .bind(position as i32)
+        .execute(pool)
+        .await?;
+    }
+
+    Ok(())
+}
+
+async fn load_release_tracks(
+    pool: &PgPool,
+    release_id: i64,
+) -> anyhow::Result<Vec<ReleaseTrackDto>> {
+    let rows = sqlx::query_as::<_, ReleaseTrackRow>(
+        "SELECT t.id, t.title::text AS title, \
+                COALESCE(NULLIF(STRING_AGG(DISTINCT a.name::text, ', '), ''), 'Unknown artist') AS artists, \
+                NULLIF(t.release_id, 0) AS release_id, r.title::text AS release_title, \
+                t.track_number, t.disc_number, t.duration_seconds, t.is_hidden \
+         FROM furumusic__track t \
+         LEFT JOIN furumusic__release r ON r.id = t.release_id \
+         LEFT JOIN furumusic__track_artist ta ON ta.track_id = t.id AND ta.role = 'main' \
+         LEFT JOIN furumusic__artist a ON a.id = ta.artist_id \
+         WHERE t.release_id = $1 \
+         GROUP BY t.id, r.id, r.title \
+         ORDER BY t.disc_number NULLS FIRST, t.track_number NULLS LAST, t.title ASC, t.id ASC",
+    )
+    .bind(release_id)
+    .fetch_all(pool)
+    .await?;
+    Ok(rows.into_iter().map(release_track_dto).collect())
+}
+
+async fn search_tracks(
+    pool: &PgPool,
+    search: &str,
+    limit: i64,
+) -> anyhow::Result<Vec<ReleaseTrackDto>> {
+    let pattern = format!("%{search}%");
+    let starts_with = format!("{search}%");
+    let rows = sqlx::query_as::<_, ReleaseTrackRow>(
+        "SELECT t.id, t.title::text AS title, \
+                COALESCE(NULLIF(STRING_AGG(DISTINCT a.name::text, ', '), ''), 'Unknown artist') AS artists, \
+                NULLIF(t.release_id, 0) AS release_id, r.title::text AS release_title, \
+                t.track_number, t.disc_number, t.duration_seconds, t.is_hidden \
+         FROM furumusic__track t \
+         LEFT JOIN furumusic__release r ON r.id = t.release_id \
+         LEFT JOIN furumusic__track_artist ta ON ta.track_id = t.id AND ta.role = 'main' \
+         LEFT JOIN furumusic__artist a ON a.id = ta.artist_id \
+         WHERE t.title ILIKE $1 OR COALESCE(r.title::text, '') ILIKE $1 OR COALESCE(a.name::text, '') ILIKE $1 \
+         GROUP BY t.id, r.id, r.title \
+         ORDER BY CASE \
+                    WHEN LOWER(t.title::text) = LOWER($2) THEN 0 \
+                    WHEN t.title ILIKE $3 THEN 1 \
+                    ELSE 2 \
+                  END, \
+                  t.title_sort ASC, t.id ASC \
+         LIMIT $4",
+    )
+    .bind(pattern)
+    .bind(search)
+    .bind(starts_with)
+    .bind(limit)
+    .fetch_all(pool)
+    .await?;
+    Ok(rows.into_iter().map(release_track_dto).collect())
+}
+
+async fn update_release_tracks(
+    pool: &PgPool,
+    release_id: i64,
+    tracks: &[ReleaseTrackUpdateRequest],
+    now: &str,
+) -> anyhow::Result<()> {
+    let mut seen_ids = HashSet::new();
+    let selected = tracks
+        .iter()
+        .filter(|track| track.id > 0 && seen_ids.insert(track.id))
+        .collect::<Vec<_>>();
+    let selected_ids = selected.iter().map(|track| track.id).collect::<Vec<_>>();
+
+    let mut tx = pool.begin().await?;
+    if selected_ids.is_empty() {
+        sqlx::query(
+            "UPDATE furumusic__track \
+             SET release_id = 0, updated_at = $2 \
+             WHERE release_id = $1",
+        )
+        .bind(release_id)
+        .bind(now)
+        .execute(&mut *tx)
+        .await?;
+    } else {
+        sqlx::query(
+            "UPDATE furumusic__track \
+             SET release_id = 0, updated_at = $2 \
+             WHERE release_id = $1 AND id <> ALL($3)",
+        )
+        .bind(release_id)
+        .bind(now)
+        .bind(&selected_ids)
+        .execute(&mut *tx)
+        .await?;
+    }
+
+    for track in selected {
+        let track_number = parse_optional_admin_i32(track.track_number.as_deref(), 1, 9999);
+        let disc_number = parse_optional_admin_i32(track.disc_number.as_deref(), 1, 999);
+        sqlx::query(
+            "UPDATE furumusic__track \
+             SET release_id = $1, track_number = $2, disc_number = $3, updated_at = $4 \
+             WHERE id = $5",
+        )
+        .bind(release_id)
+        .bind(track_number)
+        .bind(disc_number)
+        .bind(now)
+        .bind(track.id)
+        .execute(&mut *tx)
+        .await?;
+    }
+
+    tx.commit().await?;
+    Ok(())
+}
+
+fn release_track_dto(row: ReleaseTrackRow) -> ReleaseTrackDto {
+    ReleaseTrackDto {
+        id: row.id,
+        title: row.title,
+        artists: row.artists,
+        release_id: row.release_id,
+        release_title: row.release_title,
+        track_number: row.track_number,
+        disc_number: row.disc_number,
+        duration_seconds: row.duration_seconds,
+        is_hidden: row.is_hidden,
+    }
+}
+
 async fn artist_available_covers(
     pool: &PgPool,
     artist_id: i64,
@@ -2943,7 +3338,7 @@ async fn library_ids_by_filter(
         "tracks" => QueryBuilder::<Postgres>::new(
             "SELECT DISTINCT t.id \
              FROM furumusic__track t \
-             JOIN furumusic__release r ON r.id = t.release_id \
+             LEFT JOIN furumusic__release r ON r.id = t.release_id \
              LEFT JOIN furumusic__track_artist ta ON ta.track_id = t.id \
              LEFT JOIN furumusic__artist a ON a.id = ta.artist_id WHERE 1=1",
         ),
@@ -3182,7 +3577,7 @@ async fn count_library(
         "tracks" => QueryBuilder::<Postgres>::new(
             "SELECT COUNT(DISTINCT t.id) AS count \
              FROM furumusic__track t \
-             JOIN furumusic__release r ON r.id = t.release_id \
+             LEFT JOIN furumusic__release r ON r.id = t.release_id \
              LEFT JOIN furumusic__track_artist ta ON ta.track_id = t.id \
              LEFT JOIN furumusic__artist a ON a.id = ta.artist_id WHERE 1=1",
         ),
@@ -3319,13 +3714,13 @@ async fn load_track_items(
 ) -> anyhow::Result<Vec<LibraryItemRow>> {
     let mut qb = QueryBuilder::<Postgres>::new(
         "SELECT t.id, t.title::text AS title, \
-                CONCAT(r.title::text, COALESCE(' / #' || t.track_number::text, '')) AS subtitle, \
+                CONCAT(COALESCE(r.title::text, 'No release'), COALESCE(' / #' || t.track_number::text, '')) AS subtitle, \
                 t.is_hidden, COUNT(DISTINCT ta.artist_id)::bigint AS primary_count, \
                 COUNT(DISTINCT ph.id)::bigint AS secondary_count, \
                 COUNT(DISTINCT pt.playlist_id)::bigint AS tertiary_count, \
                 t.updated_at::text AS updated_at \
          FROM furumusic__track t \
-         JOIN furumusic__release r ON r.id = t.release_id \
+         LEFT JOIN furumusic__release r ON r.id = t.release_id \
          LEFT JOIN furumusic__track_artist ta ON ta.track_id = t.id \
          LEFT JOIN furumusic__artist a ON a.id = ta.artist_id \
          LEFT JOIN furumusic__play_history ph ON ph.track_id = t.id \
@@ -3341,7 +3736,7 @@ async fn load_track_items(
         qb.push_bind(pattern);
         qb.push(")");
     }
-    qb.push(" GROUP BY t.id, r.title ORDER BY r.title ASC, t.disc_number NULLS FIRST, t.track_number NULLS FIRST, t.title ASC LIMIT ");
+    qb.push(" GROUP BY t.id, r.title ORDER BY COALESCE(r.title::text, '') ASC, t.disc_number NULLS FIRST, t.track_number NULLS FIRST, t.title ASC LIMIT ");
     qb.push_bind(limit);
     qb.push(" OFFSET ");
     qb.push_bind(offset);

src/config.rs

@@ -135,6 +135,9 @@ pub struct ConfigSources {
     pub agent_concurrency: ConfigSource,
     pub lastfm_api_key: ConfigSource,
     pub lastfm_shared_secret: ConfigSource,
+    pub federation_enabled: ConfigSource,
+    pub federation_network_id: ConfigSource,
+    pub federation_save_on_listen: ConfigSource,
 }
 
 impl Default for ConfigSources {
@@ -162,6 +165,9 @@ impl Default for ConfigSources {
             agent_concurrency: ConfigSource::Default,
             lastfm_api_key: ConfigSource::Default,
             lastfm_shared_secret: ConfigSource::Default,
+            federation_enabled: ConfigSource::Default,
+            federation_network_id: ConfigSource::Default,
+            federation_save_on_listen: ConfigSource::Default,
         }
     }
 }
@@ -270,6 +276,15 @@ pub struct AppConfig {
     pub lastfm_api_key: String,
     /// Last.fm shared secret for authenticated scrobbling calls.
     pub lastfm_shared_secret: String,
+    /// Whether this server participates in the furumi federation (publishes
+    /// its library into the shared DHT and serves audio to peers).
+    pub federation_enabled: bool,
+    /// Federation network id — the shared secret every peer of the network
+    /// uses to find the others.
+    pub federation_network_id: String,
+    /// Whether a federated track requested for playback is imported into the
+    /// shared local library. This is a server-wide administrator policy.
+    pub federation_save_on_listen: bool,
 }
 
 impl Default for AppConfig {
@@ -297,6 +312,9 @@ impl Default for AppConfig {
             agent_concurrency: 2,
             lastfm_api_key: String::new(),
             lastfm_shared_secret: String::new(),
+            federation_enabled: false,
+            federation_network_id: String::new(),
+            federation_save_on_listen: false,
         }
     }
 }
@@ -325,6 +343,9 @@ impl_env_overrides!(
     agent_concurrency,
     lastfm_api_key,
     lastfm_shared_secret,
+    federation_enabled,
+    federation_network_id,
+    federation_save_on_listen,
 );
 
 impl AppConfig {
@@ -452,6 +473,9 @@ impl AppConfig {
         apply_db_field!(agent_concurrency);
         apply_db_field!(lastfm_api_key);
         apply_db_field!(lastfm_shared_secret);
+        apply_db_field!(federation_enabled);
+        apply_db_field!(federation_network_id);
+        apply_db_field!(federation_save_on_listen);
     }
 }
 

src/federation/capabilities.rs

@@ -0,0 +1,66 @@
+//! Informational publication of the protocol versions exposed by this peer.
+
+use std::time::Duration;
+
+use anyhow::Result;
+use music_dht::StreamAcceptor;
+use music_dht::capabilities::{
+    CAPABILITIES_PROTOCOL_VERSION, CapabilityManifest, CapabilityMessage, JAM_ID, read_message,
+    write_message,
+};
+
+use super::serve::AUDIO_PROTOCOL_VERSION;
+
+fn local_manifest() -> CapabilityManifest {
+    CapabilityManifest::frid("furumusic", env!("CARGO_PKG_VERSION"))
+        // The web server does not expose federation Jam yet.
+        .without_protocol(JAM_ID)
+        .with_protocol("audio", AUDIO_PROTOCOL_VERSION)
+}
+
+pub async fn serve(mut acceptor: StreamAcceptor) {
+    while let Some(stream) = acceptor.accept().await {
+        tokio::spawn(async move {
+            if let Err(error) = serve_one(stream).await {
+                tracing::debug!("capability stream failed: {error:#}");
+            }
+        });
+    }
+}
+
+async fn serve_one(mut stream: music_dht::ByteStream) -> Result<()> {
+    let response = match read_message(&mut stream).await? {
+        CapabilityMessage::Get {
+            version: CAPABILITIES_PROTOCOL_VERSION,
+        } => CapabilityMessage::Manifest {
+            manifest: local_manifest(),
+        },
+        CapabilityMessage::Get { version } => CapabilityMessage::Error {
+            message: format!("unsupported capability protocol {version}"),
+        },
+        _ => CapabilityMessage::Error {
+            message: "expected capability request".to_string(),
+        },
+    };
+    write_message(&mut stream, &response).await?;
+    stream.send.finish()?;
+    let _ = tokio::time::timeout(Duration::from_secs(2), stream.send.stopped()).await;
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn manifest_describes_only_supported_player_protocols() {
+        let manifest = local_manifest();
+        assert_eq!(manifest.application, "furumusic");
+        assert_eq!(
+            manifest.protocols.get("audio"),
+            Some(&AUDIO_PROTOCOL_VERSION)
+        );
+        assert!(!manifest.protocols.contains_key(JAM_ID));
+        manifest.validate().unwrap();
+    }
+}

src/federation/client.rs

@@ -0,0 +1,536 @@
+//! Receiving side of music federation.
+//!
+//! User-facing identity is content-addressed. An `(owner, item_id)` pair is
+//! only a source locator and several locators may resolve the same track.
+
+use std::collections::HashMap;
+
+use anyhow::{Context, Result};
+use music_dht::{ItemKind, LibraryItem, normalize_content_id};
+use serde::Serialize;
+use serde_json::{Value, json};
+use sqlx::Row as _;
+use tokio::io::AsyncReadExt;
+
+use super::{Federation, now_iso};
+
+const MAX_CATALOG_BYTES: u64 = 4 * 1024 * 1024;
+
+#[derive(Debug, Clone, Serialize)]
+pub struct TrackKeyDto {
+    pub content_id: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ArtistKeyDto {
+    pub normalized_name: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ArtistRefDto {
+    pub key: ArtistKeyDto,
+    pub name: String,
+    pub local_id: Option<i64>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ReleaseKeyDto {
+    pub normalized_title: String,
+    pub primary_artists: Vec<String>,
+    pub release_type: Option<String>,
+    pub year: Option<i32>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ReleaseRefDto {
+    pub key: ReleaseKeyDto,
+    pub local_id: Option<i64>,
+    pub title: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct FederationSourceDto {
+    pub owner: String,
+    pub item_id: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct LocalAvailabilityDto {
+    pub track_id: i64,
+    pub stream_url: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct TrackMetadataDto {
+    pub title: String,
+    pub artists: Vec<ArtistRefDto>,
+    pub featured_artists: Vec<ArtistRefDto>,
+    pub release: Option<ReleaseRefDto>,
+    pub year: Option<i32>,
+    pub duration_seconds: Option<f64>,
+    pub track_number: Option<i32>,
+    pub disc_number: Option<i32>,
+    pub cover_url: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct TrackAvailabilityDto {
+    pub state: &'static str,
+    pub local: Option<LocalAvailabilityDto>,
+    pub federation: Vec<FederationSourceDto>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct TrackDto {
+    pub key: TrackKeyDto,
+    pub metadata: TrackMetadataDto,
+    pub availability: TrackAvailabilityDto,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct SearchEvent {
+    pub search_id: String,
+    pub sequence: u64,
+    pub kind: &'static str,
+    pub peer: Option<String>,
+    pub entity_key: Value,
+    pub entity: Value,
+}
+
+impl Federation {
+    pub fn stream_artist_catalogs(
+        self: &std::sync::Arc<Self>,
+        name: String,
+    ) -> tokio::sync::mpsc::UnboundedReceiver<Result<(String, music_dht::catalog::CatalogArtist)>>
+    {
+        let (sender, receiver) = tokio::sync::mpsc::unbounded_channel();
+        let federation = std::sync::Arc::clone(self);
+        tokio::spawn(async move {
+            let result = async {
+                let service = federation.service().await?;
+                let normalized = music_dht::normalize_name(&name);
+                let outcome = service
+                    .search_network(&name)
+                    .await
+                    .map_err(|err| anyhow::anyhow!("federated artist search failed: {err}"))?;
+                let owners: std::collections::HashSet<_> = outcome
+                    .network_results
+                    .iter()
+                    .filter(|item| {
+                        (item.kind == ItemKind::Artist && item.normalized_name == normalized)
+                            || item
+                                .artist_names
+                                .iter()
+                                .chain(&item.featured_artist_names)
+                                .any(|artist| music_dht::normalize_name(artist) == normalized)
+                    })
+                    .map(|item| item.owner)
+                    .collect();
+                for owner in owners {
+                    let service = std::sync::Arc::clone(&service);
+                    let sender = sender.clone();
+                    let name = name.clone();
+                    tokio::spawn(async move {
+                        let result = tokio::time::timeout(
+                            std::time::Duration::from_secs(8),
+                            fetch_artist_catalog(&service, owner, &name),
+                        )
+                        .await
+                        .map_err(|_| anyhow::anyhow!("catalog request timed out"))
+                        .and_then(|result| result)
+                        .map(|artist| (owner.to_string(), artist));
+                        let _ = sender.send(result);
+                    });
+                }
+                Ok::<(), anyhow::Error>(())
+            }
+            .await;
+            if let Err(err) = result {
+                let _ = sender.send(Err(err));
+            }
+        });
+        receiver
+    }
+
+    /// Performs one bounded DHT search and returns entity upserts. The HTTP
+    /// layer streams each upsert independently; catalog fan-out can append
+    /// events to the same contract without changing the browser model.
+    pub async fn search_events(&self, search_id: &str, query: &str) -> Result<Vec<SearchEvent>> {
+        let query = query.trim();
+        anyhow::ensure!(!query.is_empty(), "search query is empty");
+        anyhow::ensure!(query.chars().count() <= 200, "search query is too long");
+
+        let started = std::time::Instant::now();
+        let service = self.service().await?;
+        tracing::info!(
+            search_id,
+            query,
+            connected_peers = service.connected_peers().len(),
+            known_contacts = service.known_peers().len(),
+            "federated search started"
+        );
+        let own = service.endpoint_id();
+        let result = tokio::time::timeout(
+            std::time::Duration::from_secs(20),
+            service.search_network(query),
+        )
+        .await
+        .map_err(|_| anyhow::anyhow!("federated search timed out after 20 seconds"))?
+        .map_err(|err| anyhow::anyhow!("federated search failed: {err}"))?;
+        tracing::info!(
+            search_id,
+            query,
+            local_results = result.local_results.len(),
+            network_results = result.network_results.len(),
+            queried_nodes = result.queried_nodes,
+            elapsed_ms = started.elapsed().as_millis() as u64,
+            "federated DHT search finished"
+        );
+        let all_items: Vec<LibraryItem> = result
+            .local_results
+            .into_iter()
+            .chain(result.network_results)
+            .collect();
+
+        let pool = self.pool().await?;
+        let mut by_content: HashMap<String, TrackDto> = HashMap::new();
+        for item in all_items.iter().filter(|item| item.kind == ItemKind::Track) {
+            let Some(content_id) = item.content_id.as_deref().and_then(normalize_content_id) else {
+                // A globally usable track reference must be verifiable.
+                continue;
+            };
+            let local = local_availability(&pool, &content_id).await?;
+            let source = FederationSourceDto {
+                owner: item.owner.to_string(),
+                item_id: hex(item.id.as_bytes()),
+            };
+            let entry = by_content.entry(content_id.clone()).or_insert_with(|| {
+                track_from_item(content_id.clone(), item, local, item.owner == own)
+            });
+            if !entry.availability.federation.iter().any(|candidate| {
+                candidate.owner == source.owner && candidate.item_id == source.item_id
+            }) {
+                entry.availability.federation.push(source);
+            }
+            if entry.availability.local.is_some() {
+                entry.availability.state = "local";
+            }
+        }
+
+        let mut tracks: Vec<_> = by_content.into_values().collect();
+        tracks.sort_by(|left, right| {
+            left.metadata
+                .title
+                .to_lowercase()
+                .cmp(&right.metadata.title.to_lowercase())
+        });
+
+        let mut events = Vec::with_capacity(all_items.len());
+        for (index, track) in tracks.into_iter().enumerate() {
+            persist_track_ref(&pool, &track).await?;
+            let peer = track
+                .availability
+                .federation
+                .first()
+                .map(|source| source.owner.clone());
+            events.push(SearchEvent {
+                search_id: search_id.to_owned(),
+                sequence: index as u64 + 1,
+                kind: "federation.track",
+                peer,
+                entity_key: serde_json::to_value(&track.key)?,
+                entity: serde_json::to_value(track)?,
+            });
+        }
+        let mut artist_peers: HashMap<String, (String, Vec<String>)> = HashMap::new();
+        let mut releases: HashMap<String, Value> = HashMap::new();
+        for item in &all_items {
+            match item.kind {
+                ItemKind::Artist => {
+                    let key = music_dht::normalize_name(&item.name);
+                    let entry = artist_peers
+                        .entry(key)
+                        .or_insert_with(|| (item.name.clone(), Vec::new()));
+                    let owner = item.owner.to_string();
+                    if !entry.1.contains(&owner) {
+                        entry.1.push(owner);
+                    }
+                }
+                ItemKind::Release => {
+                    let artist_keys: Vec<String> = item
+                        .artist_names
+                        .iter()
+                        .map(|name| music_dht::normalize_name(name))
+                        .collect();
+                    let normalized_title = music_dht::normalize_name(&item.name);
+                    let cover_url = all_items
+                        .iter()
+                        .find(|track| {
+                            track.kind == ItemKind::Track
+                                && track.release_title.as_deref().is_some_and(|title| {
+                                    music_dht::normalize_name(title) == normalized_title
+                                })
+                                && track.year == item.year
+                        })
+                        .map(|track| {
+                            format!(
+                                "/api/player/federation/tracks/artwork?owner={}&item_id={}",
+                                track.owner,
+                                hex(track.id.as_bytes())
+                            )
+                        });
+                    let key = format!(
+                        "{}|{}|{}",
+                        normalized_title,
+                        artist_keys.join(","),
+                        item.year.map_or_else(String::new, |year| year.to_string())
+                    );
+                    releases.entry(key.clone()).or_insert_with(|| {
+                        json!({
+                            "key": {
+                                "normalized_title": music_dht::normalize_name(&item.name),
+                                "primary_artists": artist_keys,
+                                "release_type": null,
+                                "year": item.year,
+                            },
+                            "title": item.name,
+                            "artists": item.artist_names,
+                            "year": item.year,
+                            "cover_url": cover_url,
+                            "sources": [{
+                                "owner": item.owner.to_string(),
+                                "item_id": hex(item.id.as_bytes()),
+                            }],
+                        })
+                    });
+                }
+                ItemKind::Track => {}
+            }
+        }
+        for (key, (name, peers)) in artist_peers {
+            let sequence = events.len() as u64 + 1;
+            events.push(SearchEvent {
+                search_id: search_id.to_owned(),
+                sequence,
+                kind: "federation.artist",
+                peer: peers.first().cloned(),
+                entity_key: json!({ "normalized_name": key }),
+                entity: json!({
+                    "key": { "normalized_name": key },
+                    "name": name,
+                    "image_url": null,
+                    "peers": peers,
+                }),
+            });
+        }
+        for (key, release) in releases {
+            let sequence = events.len() as u64 + 1;
+            events.push(SearchEvent {
+                search_id: search_id.to_owned(),
+                sequence,
+                kind: "federation.release",
+                peer: None,
+                entity_key: json!({ "composite": key }),
+                entity: release,
+            });
+        }
+        tracing::info!(
+            search_id,
+            query,
+            events = events.len(),
+            elapsed_ms = started.elapsed().as_millis() as u64,
+            "federated search response ready"
+        );
+        Ok(events)
+    }
+}
+
+async fn fetch_artist_catalog(
+    service: &music_dht::MusicDhtService,
+    owner: music_dht::EndpointId,
+    artist: &str,
+) -> Result<music_dht::catalog::CatalogArtist> {
+    let mut stream = service
+        .open_stream(owner, super::CATALOG_ALPN)
+        .await
+        .map_err(|err| anyhow::anyhow!("cannot reach catalog peer: {err}"))?;
+    let mut request = serde_json::to_vec(&music_dht::catalog::CatalogRequest {
+        artist: artist.to_owned(),
+        want: Some("catalog".to_owned()),
+        ..Default::default()
+    })?;
+    request.push(b'\n');
+    stream.send.write_all(&request).await?;
+    stream.send.finish()?;
+    let mut payload = Vec::new();
+    stream
+        .recv
+        .take(MAX_CATALOG_BYTES + 1)
+        .read_to_end(&mut payload)
+        .await?;
+    anyhow::ensure!(
+        payload.len() as u64 <= MAX_CATALOG_BYTES,
+        "catalog response is too large"
+    );
+    let response: music_dht::catalog::CatalogResponse =
+        serde_json::from_slice(&payload).context("invalid catalog response")?;
+    anyhow::ensure!(
+        response.ok,
+        "peer refused catalog: {}",
+        response.error.unwrap_or_else(|| "unknown error".to_owned())
+    );
+    response.artist.context("peer returned no artist catalog")
+}
+
+fn track_from_item(
+    content_id: String,
+    item: &LibraryItem,
+    local: Option<LocalAvailabilityDto>,
+    own: bool,
+) -> TrackDto {
+    let owner = item.owner.to_string();
+    let item_id = hex(item.id.as_bytes());
+    let artists = artist_refs(&item.artist_names);
+    let featured_artists = artist_refs(&item.featured_artist_names);
+    let release = item.release_title.as_ref().map(|title| ReleaseRefDto {
+        key: ReleaseKeyDto {
+            normalized_title: music_dht::normalize_name(title),
+            primary_artists: item
+                .artist_names
+                .iter()
+                .map(|artist| music_dht::normalize_name(artist))
+                .collect(),
+            release_type: None,
+            year: item.year,
+        },
+        local_id: None,
+        title: title.clone(),
+    });
+    let state = if local.is_some() || own {
+        "local"
+    } else {
+        "federated"
+    };
+    TrackDto {
+        key: TrackKeyDto { content_id },
+        metadata: TrackMetadataDto {
+            title: item.name.clone(),
+            artists,
+            featured_artists,
+            release,
+            year: item.year,
+            duration_seconds: item.duration_seconds,
+            track_number: item.track_number,
+            disc_number: item.disc_number,
+            cover_url: Some(format!(
+                "/api/player/federation/tracks/artwork?owner={owner}&item_id={item_id}"
+            )),
+        },
+        availability: TrackAvailabilityDto {
+            state,
+            local,
+            federation: vec![FederationSourceDto { owner, item_id }],
+        },
+    }
+}
+
+fn artist_refs(names: &[String]) -> Vec<ArtistRefDto> {
+    names
+        .iter()
+        .map(|name| ArtistRefDto {
+            key: ArtistKeyDto {
+                normalized_name: music_dht::normalize_name(name),
+            },
+            name: name.clone(),
+            local_id: None,
+        })
+        .collect()
+}
+
+async fn local_availability(
+    pool: &sqlx::PgPool,
+    content_id: &str,
+) -> Result<Option<LocalAvailabilityDto>> {
+    let row = sqlx::query(
+        "SELECT t.id
+           FROM furumusic__federation_content_id_cache c
+           JOIN furumusic__track t ON t.audio_file_id = c.media_file_id
+          WHERE c.content_id = $1 AND t.is_hidden = false
+          LIMIT 1",
+    )
+    .bind(content_id)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| {
+        let track_id: i64 = row.get(0);
+        LocalAvailabilityDto {
+            track_id,
+            stream_url: format!("/api/player/stream/{track_id}"),
+        }
+    }))
+}
+
+async fn persist_track_ref(pool: &sqlx::PgPool, track: &TrackDto) -> Result<()> {
+    let metadata = serde_json::to_value(&track.metadata)?;
+    let local_id = track
+        .availability
+        .local
+        .as_ref()
+        .map(|local| local.track_id);
+    let row = sqlx::query(
+        "INSERT INTO furumusic__track_ref
+            (content_id, local_track_id, title, release_title, year,
+             duration_seconds, metadata_json, metadata_authority, created_at, updated_at)
+         VALUES ($1, $2, $3, $4, $5, $6, $7, 'federation', $8, $8)
+         ON CONFLICT (content_id) DO UPDATE SET
+            local_track_id = COALESCE(furumusic__track_ref.local_track_id, EXCLUDED.local_track_id),
+            title = EXCLUDED.title,
+            release_title = EXCLUDED.release_title,
+            year = EXCLUDED.year,
+            duration_seconds = EXCLUDED.duration_seconds,
+            metadata_json = EXCLUDED.metadata_json,
+            updated_at = EXCLUDED.updated_at
+         RETURNING id",
+    )
+    .bind(&track.key.content_id)
+    .bind(local_id)
+    .bind(&track.metadata.title)
+    .bind(
+        track
+            .metadata
+            .release
+            .as_ref()
+            .map(|release| &release.title),
+    )
+    .bind(track.metadata.year)
+    .bind(track.metadata.duration_seconds)
+    .bind(metadata)
+    .bind(now_iso())
+    .fetch_one(pool)
+    .await
+    .context("persisting content-addressed track reference failed")?;
+    let track_ref_id: i64 = row.get(0);
+    for source in &track.availability.federation {
+        sqlx::query(
+            "INSERT INTO furumusic__federation_track_source
+                (track_ref_id, owner_peer_id, item_id, last_seen_ms, metadata_json)
+             VALUES ($1, $2, $3, $4, $5)
+             ON CONFLICT (owner_peer_id, item_id) DO UPDATE SET
+                track_ref_id = EXCLUDED.track_ref_id,
+                last_seen_ms = EXCLUDED.last_seen_ms,
+                metadata_json = EXCLUDED.metadata_json",
+        )
+        .bind(track_ref_id)
+        .bind(&source.owner)
+        .bind(&source.item_id)
+        .bind(chrono::Utc::now().timestamp_millis())
+        .bind(json!({ "track": track.metadata }))
+        .execute(pool)
+        .await?;
+    }
+    Ok(())
+}
+
+fn hex(bytes: &[u8]) -> String {
+    bytes.iter().map(|byte| format!("{byte:02x}")).collect()
+}

src/federation/mod.rs

@@ -0,0 +1,999 @@
+//! P2P federation for the furumusic server.
+//!
+//! When enabled in the admin settings, the server becomes a regular peer of
+//! the furumi federation: it publishes its whole visible library (artists,
+//! releases, tracks — names and small metadata, never files) into the
+//! shared DHT and serves audio, track metadata, cover art and per-artist
+//! catalogs to other peers (TUI clients) over the same wire protocols the
+//! clients speak among themselves. Serve-only: the server does not search
+//! or download from other peers.
+//!
+//! Settings are the regular admin config entries (`federation_enabled`,
+//! `federation_network_id`, `federation_save_on_listen`) and apply on the fly — saving the settings
+//! starts, stops or re-joins the node without a server restart.
+
+mod capabilities;
+pub mod client;
+pub mod devices;
+mod receive;
+mod serve;
+mod storage;
+
+use std::collections::{HashMap, HashSet, VecDeque};
+use std::path::PathBuf;
+use std::sync::{Arc, OnceLock};
+use std::time::Duration;
+
+use anyhow::{Context, Result};
+use music_dht::capabilities::CAPABILITIES_ALPN;
+use music_dht::{
+    ByteStream, ByteStreamConnectionStats, ItemKind, ItemSpec, MusicDhtConfig, MusicDhtService,
+    NetworkId, PeerTicket, PublishStats, RendezvousConfig, SyncStats,
+};
+use serde_json::{Value, json};
+use sqlx::PgPool;
+use sqlx::Row as _;
+
+use crate::config::AppConfig;
+use storage::PostgresFederationStorage;
+
+pub use serve::{AUDIO_ALPN, CATALOG_ALPN};
+
+/// How often the published library is re-synchronized with the database.
+const SYNC_INTERVAL: Duration = Duration::from_secs(60);
+const TRANSPORT_SAMPLE_LIMIT: usize = 16;
+
+struct Running {
+    service: Arc<MusicDhtService>,
+    network_name: String,
+    tasks: Vec<tokio::task::JoinHandle<()>>,
+}
+
+struct ContentHashJob {
+    media_file_id: i64,
+    sha256_hash: String,
+    file_path: String,
+}
+
+#[derive(Clone)]
+struct CachedArtwork {
+    bytes: Vec<u8>,
+    mime: String,
+    fetched_at: std::time::Instant,
+}
+
+#[derive(Debug, Clone)]
+struct TransportSample {
+    at: String,
+    protocol: &'static str,
+    direction: &'static str,
+    phase: &'static str,
+    peer_id: String,
+    selected_path: String,
+    open_paths: usize,
+    direct_paths: usize,
+    relay_paths: usize,
+    custom_paths: usize,
+    selected_rtt_ms: Option<u64>,
+    selected_tx_bytes: u64,
+    selected_rx_bytes: u64,
+    total_tx_bytes: u64,
+    total_rx_bytes: u64,
+    lost_packets: u64,
+    lost_bytes: u64,
+}
+
+impl TransportSample {
+    fn from_stats(
+        protocol: &'static str,
+        direction: &'static str,
+        phase: &'static str,
+        stats: ByteStreamConnectionStats,
+    ) -> Self {
+        Self {
+            at: now_iso(),
+            protocol,
+            direction,
+            phase,
+            peer_id: stats.peer_id.to_string(),
+            selected_path: stats.selected_path.as_str().to_string(),
+            open_paths: stats.open_paths,
+            direct_paths: stats.direct_paths,
+            relay_paths: stats.relay_paths,
+            custom_paths: stats.custom_paths,
+            selected_rtt_ms: stats
+                .selected_rtt
+                .map(|duration| duration.as_millis() as u64),
+            selected_tx_bytes: stats.selected_tx_bytes,
+            selected_rx_bytes: stats.selected_rx_bytes,
+            total_tx_bytes: stats.total_tx_bytes,
+            total_rx_bytes: stats.total_rx_bytes,
+            lost_packets: stats.lost_packets,
+            lost_bytes: stats.lost_bytes,
+        }
+    }
+}
+
+#[derive(Debug, Default)]
+struct TransportStatsState {
+    total_samples: u64,
+    direct_samples: u64,
+    relay_samples: u64,
+    custom_samples: u64,
+    unknown_samples: u64,
+    audio_samples: u64,
+    catalog_samples: u64,
+    sync_samples: u64,
+    last: VecDeque<TransportSample>,
+}
+
+#[derive(Debug, Default)]
+pub struct TransportStats {
+    inner: std::sync::Mutex<TransportStatsState>,
+}
+
+impl TransportStats {
+    fn reset(&self) {
+        *lock(&self.inner) = TransportStatsState::default();
+    }
+
+    fn record(
+        &self,
+        protocol: &'static str,
+        direction: &'static str,
+        phase: &'static str,
+        stats: ByteStreamConnectionStats,
+    ) {
+        let sample = TransportSample::from_stats(protocol, direction, phase, stats);
+        let mut state = lock(&self.inner);
+        state.total_samples += 1;
+        match sample.selected_path.as_str() {
+            "direct" => state.direct_samples += 1,
+            "relay" => state.relay_samples += 1,
+            "custom" => state.custom_samples += 1,
+            _ => state.unknown_samples += 1,
+        }
+        match protocol {
+            "audio" => state.audio_samples += 1,
+            "catalog" => state.catalog_samples += 1,
+            "device-sync" => state.sync_samples += 1,
+            _ => {}
+        }
+        state.last.push_front(sample);
+        while state.last.len() > TRANSPORT_SAMPLE_LIMIT {
+            state.last.pop_back();
+        }
+    }
+
+    fn snapshot(&self) -> Value {
+        let state = lock(&self.inner);
+        let latest = state.last.front();
+        json!({
+            "total_samples": state.total_samples,
+            "direct_samples": state.direct_samples,
+            "relay_samples": state.relay_samples,
+            "custom_samples": state.custom_samples,
+            "unknown_samples": state.unknown_samples,
+            "audio_samples": state.audio_samples,
+            "catalog_samples": state.catalog_samples,
+            "sync_samples": state.sync_samples,
+            "last_path": latest.map(|sample| sample.selected_path.clone()),
+            "last_rtt_ms": latest.and_then(|sample| sample.selected_rtt_ms),
+            "last_peer": latest.map(|sample| sample.peer_id.clone()),
+            "last": state.last.iter().map(|sample| json!({
+                "at": sample.at,
+                "protocol": sample.protocol,
+                "direction": sample.direction,
+                "phase": sample.phase,
+                "peer_id": sample.peer_id,
+                "selected_path": sample.selected_path,
+                "open_paths": sample.open_paths,
+                "direct_paths": sample.direct_paths,
+                "relay_paths": sample.relay_paths,
+                "custom_paths": sample.custom_paths,
+                "selected_rtt_ms": sample.selected_rtt_ms,
+                "selected_tx_bytes": sample.selected_tx_bytes,
+                "selected_rx_bytes": sample.selected_rx_bytes,
+                "total_tx_bytes": sample.total_tx_bytes,
+                "total_rx_bytes": sample.total_rx_bytes,
+                "lost_packets": sample.lost_packets,
+                "lost_bytes": sample.lost_bytes,
+            })).collect::<Vec<_>>(),
+        })
+    }
+}
+
+pub fn record_stream_transport(
+    stats: &Arc<TransportStats>,
+    protocol: &'static str,
+    direction: &'static str,
+    phase: &'static str,
+    stream: &ByteStream,
+) {
+    stats.record(protocol, direction, phase, stream.connection_stats());
+}
+
+pub struct Federation {
+    /// Transport data directory; server-side DHT state and identity live in PostgreSQL.
+    data_dir: PathBuf,
+    database_url: std::sync::Mutex<String>,
+    storage_dir: std::sync::Mutex<String>,
+    save_on_listen: std::sync::atomic::AtomicBool,
+    content_cache: std::sync::Mutex<HashMap<i64, (String, String)>>,
+    content_pending: std::sync::Mutex<HashSet<i64>>,
+    prepared_cache: std::sync::Mutex<HashMap<String, (PathBuf, String)>>,
+    artwork_cache: std::sync::Mutex<HashMap<String, CachedArtwork>>,
+    download_locks: std::sync::Mutex<HashMap<String, Arc<tokio::sync::Mutex<()>>>>,
+    pool: tokio::sync::OnceCell<PgPool>,
+    running: tokio::sync::Mutex<Option<Running>>,
+    last_sync: std::sync::Mutex<Option<String>>,
+    last_error: std::sync::Mutex<Option<String>>,
+    transport_stats: Arc<TransportStats>,
+}
+
+fn now_iso() -> String {
+    chrono::Utc::now().format("%Y-%m-%dT%H:%M:%SZ").to_string()
+}
+
+fn lock<T>(mutex: &std::sync::Mutex<T>) -> std::sync::MutexGuard<'_, T> {
+    mutex
+        .lock()
+        .unwrap_or_else(std::sync::PoisonError::into_inner)
+}
+
+/// The process-wide federation handle.
+pub fn handle() -> Arc<Federation> {
+    static HANDLE: OnceLock<Arc<Federation>> = OnceLock::new();
+    Arc::clone(HANDLE.get_or_init(|| {
+        Arc::new(Federation {
+            data_dir: PathBuf::from(crate::media_paths::resolve_config_path("federation")),
+            database_url: std::sync::Mutex::new(String::new()),
+            storage_dir: std::sync::Mutex::new(String::new()),
+            save_on_listen: std::sync::atomic::AtomicBool::new(false),
+            content_cache: std::sync::Mutex::new(Default::default()),
+            content_pending: std::sync::Mutex::new(Default::default()),
+            prepared_cache: std::sync::Mutex::new(Default::default()),
+            artwork_cache: std::sync::Mutex::new(Default::default()),
+            download_locks: std::sync::Mutex::new(Default::default()),
+            pool: tokio::sync::OnceCell::new(),
+            running: tokio::sync::Mutex::new(None),
+            last_sync: std::sync::Mutex::new(None),
+            last_error: std::sync::Mutex::new(None),
+            transport_stats: Arc::new(TransportStats::default()),
+        })
+    }))
+}
+
+impl Federation {
+    fn set_error(&self, message: Option<String>) {
+        *lock(&self.last_error) = message;
+    }
+
+    async fn pool(&self) -> Result<PgPool> {
+        let url = lock(&self.database_url).clone();
+        anyhow::ensure!(!url.is_empty(), "database is not configured");
+        let pool = self
+            .pool
+            .get_or_try_init(|| async {
+                sqlx::postgres::PgPoolOptions::new()
+                    .max_connections(4)
+                    .connect(&url)
+                    .await
+            })
+            .await?;
+        Ok(pool.clone())
+    }
+
+    /// Starts the node at boot when federation was left enabled. The
+    /// settings live in the config KV table, so this waits for the database
+    /// and resolves the same default → DB → env precedence the config uses.
+    pub async fn boot(self: &Arc<Self>, config: &AppConfig) {
+        *lock(&self.database_url) = config.database_url.clone();
+        if config.database_url.is_empty() {
+            return;
+        }
+        let pool = match self.pool().await {
+            Ok(pool) => pool,
+            Err(err) => {
+                tracing::warn!("federation boot: database unavailable: {err:#}");
+                return;
+            }
+        };
+        // `config` carries defaults + env; overlay the DB rows for fields
+        // that have no env override (env > DB > default).
+        let mut effective = config.clone();
+        let rows = sqlx::query(
+            "SELECT key, value FROM furumusic__config_entry
+             WHERE key IN ('federation_enabled', 'federation_network_id',
+                           'federation_save_on_listen', 'agent_storage_dir')",
+        )
+        .fetch_all(&pool)
+        .await
+        .unwrap_or_default();
+        for row in rows {
+            let key: String = row.get(0);
+            let value: String = row.get(1);
+            let env_key = format!("FURU_{}", key.to_ascii_uppercase());
+            if std::env::var(&env_key).is_ok() {
+                continue;
+            }
+            match key.as_str() {
+                "federation_enabled" => {
+                    if let Ok(parsed) = value.parse() {
+                        effective.federation_enabled = parsed;
+                    }
+                }
+                "federation_network_id" => effective.federation_network_id = value,
+                "federation_save_on_listen" => {
+                    if let Ok(parsed) = value.parse() {
+                        effective.federation_save_on_listen = parsed;
+                    }
+                }
+                "agent_storage_dir" => {
+                    effective.agent_storage_dir = crate::media_paths::resolve_config_path(&value);
+                }
+                _ => {}
+            }
+        }
+        self.apply(&effective).await;
+    }
+
+    /// Applies the effective configuration: starts, stops or re-joins the
+    /// node. Called at boot and every time the admin settings are saved.
+    pub async fn apply(self: &Arc<Self>, config: &AppConfig) {
+        *lock(&self.database_url) = config.database_url.clone();
+        *lock(&self.storage_dir) = config.agent_storage_dir.clone();
+        self.save_on_listen.store(
+            config.federation_save_on_listen,
+            std::sync::atomic::Ordering::Relaxed,
+        );
+        let network = config.federation_network_id.trim().to_string();
+        if config.federation_enabled && !network.is_empty() {
+            if let Err(err) = self.start(network, config.agent_storage_dir.clone()).await {
+                tracing::error!("federation start failed: {err:#}");
+                self.set_error(Some(format!("start failed: {err}")));
+            }
+        } else {
+            self.stop().await;
+        }
+    }
+
+    /// Starts the DHT node. Idempotent per network name; a node on another
+    /// network is stopped and re-joined.
+    async fn start(self: &Arc<Self>, network_name: String, storage_dir: String) -> Result<()> {
+        let pool = self.pool().await?;
+        let mut guard = self.running.lock().await;
+        if let Some(running) = guard.as_ref() {
+            if running.network_name == network_name {
+                return Ok(());
+            }
+            stop_running(guard.take()).await;
+        }
+
+        let dht_storage = Arc::new(PostgresFederationStorage::new(pool.clone()).await?);
+        let secret_key = dht_storage.load_or_create_secret_key().await?;
+        self.transport_stats.reset();
+
+        let config = MusicDhtConfig::builder()
+            .data_dir(&self.data_dir)
+            .network_id(NetworkId::from_name(&network_name))
+            // Peers of the network find each other knowing only its name.
+            .rendezvous(RendezvousConfig::default())
+            .stream_protocol(AUDIO_ALPN)
+            .stream_protocol(CATALOG_ALPN)
+            .stream_protocol(devices::SYNC_ALPN)
+            .schema_independent_stream_protocol(CAPABILITIES_ALPN)
+            .build()
+            .map_err(|err| anyhow::anyhow!("invalid federation config: {err}"))?;
+        let (service, mut events) =
+            MusicDhtService::start_with_storage_and_secret_key(config, dht_storage, secret_key)
+                .await
+                .map_err(|err| anyhow::anyhow!("failed to start the DHT node: {err}"))?;
+        let service = Arc::new(service);
+        tracing::info!(
+            endpoint_id = %service.endpoint_id(),
+            network = %network_name,
+            "federation started"
+        );
+
+        // Drain DHT events into the log; the channel is bounded.
+        let event_task = tokio::spawn(async move {
+            while let Some(event) = events.recv().await {
+                tracing::debug!("federation event: {event:?}");
+            }
+        });
+        // Keep the published library in sync with the database.
+        let sync_self = Arc::clone(self);
+        let sync_service = Arc::clone(&service);
+        let sync_task = tokio::spawn(async move {
+            let mut interval = tokio::time::interval(SYNC_INTERVAL);
+            loop {
+                interval.tick().await;
+                let _ = sync_self.sync_once(&sync_service).await;
+            }
+        });
+        // Serve audio and catalog requests from other peers.
+        let audio_acceptor = service
+            .stream_acceptor(AUDIO_ALPN)
+            .map_err(|err| anyhow::anyhow!("failed to take the audio acceptor: {err}"))?;
+        let audio_task = tokio::spawn(serve::serve_audio(
+            audio_acceptor,
+            pool.clone(),
+            storage_dir.clone(),
+            service.endpoint_id(),
+            Arc::clone(&self.transport_stats),
+        ));
+        let catalog_acceptor = service
+            .stream_acceptor(CATALOG_ALPN)
+            .map_err(|err| anyhow::anyhow!("failed to take the catalog acceptor: {err}"))?;
+        let catalog_task = tokio::spawn(serve::serve_catalog(
+            catalog_acceptor,
+            pool.clone(),
+            storage_dir,
+            service.endpoint_id(),
+            Arc::clone(&self.transport_stats),
+        ));
+        let device_acceptor = service
+            .stream_acceptor(devices::SYNC_ALPN)
+            .map_err(|err| anyhow::anyhow!("failed to take the device-sync acceptor: {err}"))?;
+        let device_hub = crate::player::PlayerDeviceHub::shared();
+        let device_task = tokio::spawn(devices::serve_peers(
+            device_acceptor,
+            pool.clone(),
+            Arc::clone(&service),
+            Arc::clone(&device_hub),
+            Arc::clone(&self.transport_stats),
+        ));
+        let device_sync_task = tokio::spawn(devices::sync_loop(
+            pool,
+            Arc::clone(&service),
+            device_hub,
+            Arc::clone(&self.transport_stats),
+        ));
+        let capabilities_acceptor = service
+            .stream_acceptor(CAPABILITIES_ALPN)
+            .map_err(|err| anyhow::anyhow!("failed to take the capabilities acceptor: {err}"))?;
+        let capabilities_task = tokio::spawn(capabilities::serve(capabilities_acceptor));
+
+        *guard = Some(Running {
+            service,
+            network_name,
+            tasks: vec![
+                event_task,
+                sync_task,
+                audio_task,
+                catalog_task,
+                device_task,
+                device_sync_task,
+                capabilities_task,
+            ],
+        });
+        self.set_error(None);
+        drop(guard);
+        // Publish right away instead of waiting for the first timer tick.
+        self.spawn_sync_soon().await;
+        Ok(())
+    }
+
+    async fn stop(&self) {
+        let mut guard = self.running.lock().await;
+        stop_running(guard.take()).await;
+    }
+
+    async fn service(&self) -> Result<Arc<MusicDhtService>> {
+        self.running
+            .lock()
+            .await
+            .as_ref()
+            .map(|running| Arc::clone(&running.service))
+            .context("federation is not running")
+    }
+
+    async fn spawn_sync_soon(self: &Arc<Self>) {
+        if let Ok(service) = self.service().await {
+            let fed = Arc::clone(self);
+            tokio::spawn(async move {
+                let _ = fed.sync_once(&service).await;
+            });
+        }
+    }
+
+    pub async fn sync_now(self: &Arc<Self>) -> Result<()> {
+        let service = self.service().await?;
+        let sync_stats = self.sync_once(&service).await?;
+        let publish_stats = match service.republish().await {
+            Ok(stats) => stats,
+            Err(err) => {
+                tracing::warn!("federation republish failed: {err}");
+                self.set_error(Some(format!("republish failed: {err}")));
+                anyhow::bail!("republish failed: {err}");
+            }
+        };
+        self.record_publish_success(sync_stats, publish_stats);
+        Ok(())
+    }
+
+    async fn sync_once(self: &Arc<Self>, service: &MusicDhtService) -> Result<SyncStats> {
+        let specs = match self.collect_specs().await {
+            Ok(specs) => specs,
+            Err(err) => {
+                tracing::warn!("federation sync: library read failed: {err:#}");
+                self.set_error(Some(format!("library read failed: {err}")));
+                anyhow::bail!("library read failed: {err}");
+            }
+        };
+        match service.sync_library(specs).await {
+            Ok(stats) => {
+                self.record_sync_success(stats);
+                if stats.failed > 0 {
+                    self.set_error(Some(format!(
+                        "{} item(s) failed to publish in the last sync",
+                        stats.failed
+                    )));
+                } else {
+                    self.set_error(None);
+                }
+                Ok(stats)
+            }
+            Err(err) => {
+                tracing::warn!("federation sync failed: {err}");
+                self.set_error(Some(format!("sync failed: {err}")));
+                Err(anyhow::anyhow!("sync failed: {err}"))
+            }
+        }
+    }
+
+    fn record_sync_success(&self, stats: SyncStats) {
+        *lock(&self.last_sync) = Some(format!(
+            "{} (+{} ~{} −{}, unchanged {}, failed {})",
+            now_iso(),
+            stats.added,
+            stats.updated,
+            stats.removed,
+            stats.unchanged,
+            stats.failed
+        ));
+    }
+
+    fn record_publish_success(&self, sync_stats: SyncStats, publish_stats: PublishStats) {
+        *lock(&self.last_sync) = Some(format!(
+            "{} (+{} ~{} −{}, unchanged {}, failed {}; republished {} records, {} keys, remote nodes {})",
+            now_iso(),
+            sync_stats.added,
+            sync_stats.updated,
+            sync_stats.removed,
+            sync_stats.unchanged,
+            sync_stats.failed,
+            publish_stats.records,
+            publish_stats.keys,
+            publish_stats.remote_nodes,
+        ));
+        self.set_error(None);
+    }
+
+    /// Everything the regular player shows, as DHT item specs: non-hidden
+    /// artists, releases and tracks (a track also hides with its release).
+    async fn collect_specs(self: &Arc<Self>) -> Result<Vec<ItemSpec>> {
+        let pool = self.pool().await?;
+        let mut specs = Vec::new();
+
+        let artists = sqlx::query("SELECT id, name FROM furumusic__artist WHERE is_hidden = false")
+            .fetch_all(&pool)
+            .await?;
+        for row in &artists {
+            let id: i64 = row.get(0);
+            specs.push(ItemSpec {
+                local_key: format!("artist:{id}"),
+                kind: ItemKind::Artist,
+                name: row.get(1),
+                artist_names: Vec::new(),
+                featured_artist_names: Vec::new(),
+                year: None,
+                release_type: None,
+                release_title: None,
+                track_number: None,
+                disc_number: None,
+                duration_seconds: None,
+                content_id: None,
+            });
+        }
+
+        let release_artists = sqlx::query(
+            "SELECT ra.release_id, a.name FROM furumusic__release_artist ra
+             JOIN furumusic__artist a ON a.id = ra.artist_id
+             ORDER BY ra.release_id, ra.position",
+        )
+        .fetch_all(&pool)
+        .await?;
+        let mut artists_of_release: std::collections::HashMap<i64, Vec<String>> =
+            Default::default();
+        for row in &release_artists {
+            artists_of_release
+                .entry(row.get(0))
+                .or_default()
+                .push(row.get(1));
+        }
+        let releases = sqlx::query(
+            "SELECT id, title, year, release_type FROM furumusic__release
+             WHERE is_hidden = false",
+        )
+        .fetch_all(&pool)
+        .await?;
+        for row in &releases {
+            let id: i64 = row.get(0);
+            specs.push(ItemSpec {
+                local_key: format!("release:{id}"),
+                kind: ItemKind::Release,
+                name: row.get(1),
+                artist_names: artists_of_release.remove(&id).unwrap_or_default(),
+                featured_artist_names: Vec::new(),
+                year: row.get(2),
+                release_type: row.get(3),
+                release_title: None,
+                track_number: None,
+                disc_number: None,
+                duration_seconds: None,
+                content_id: None,
+            });
+        }
+
+        let track_artists = sqlx::query(
+            "SELECT ta.track_id, a.name, ta.role FROM furumusic__track_artist ta
+             JOIN furumusic__artist a ON a.id = ta.artist_id
+             WHERE ta.role IN ('main', 'featuring')
+             ORDER BY ta.track_id,
+                      CASE ta.role WHEN 'main' THEN 0 ELSE 1 END,
+                      ta.position",
+        )
+        .fetch_all(&pool)
+        .await?;
+        let mut artists_of_track: std::collections::HashMap<i64, Vec<String>> = Default::default();
+        let mut featured_of_track: std::collections::HashMap<i64, Vec<String>> = Default::default();
+        for row in &track_artists {
+            let id: i64 = row.get(0);
+            let name: String = row.get(1);
+            if row.get::<String, _>(2) == "featuring" {
+                featured_of_track.entry(id).or_default().push(name);
+            } else {
+                artists_of_track.entry(id).or_default().push(name);
+            }
+        }
+        let tracks = sqlx::query(
+            "SELECT t.id, t.title, COALESCE(t.year, r.year), t.duration_seconds,
+                    r.title, r.release_type, t.track_number, t.disc_number,
+                    t.audio_file_id, m.file_path, m.sha256_hash, c.content_id
+             FROM furumusic__track t
+             JOIN furumusic__release r ON r.id = t.release_id
+             JOIN furumusic__media_file m ON m.id = t.audio_file_id
+             LEFT JOIN furumusic__federation_content_id_cache c
+                    ON c.media_file_id = m.id AND c.sha256_hash = m.sha256_hash
+             WHERE t.is_hidden = false AND r.is_hidden = false",
+        )
+        .fetch_all(&pool)
+        .await?;
+        let storage_dir = lock(&self.storage_dir).clone();
+        let mut content_hash_jobs = Vec::new();
+        for row in &tracks {
+            let id: i64 = row.get(0);
+            let duration: f64 = row.get(3);
+            let media_file_id: i64 = row.get(8);
+            let file_path: String = row.get(9);
+            let sha256_hash: String = row.get(10);
+            let cached_content_id: Option<String> = row.get(11);
+            let content_id = cached_content_id
+                .or_else(|| self.cached_content_id_for_media(media_file_id, &sha256_hash));
+            if content_id.is_none()
+                && !storage_dir.trim().is_empty()
+                && self.mark_content_hash_pending(media_file_id)
+            {
+                content_hash_jobs.push(ContentHashJob {
+                    media_file_id,
+                    sha256_hash,
+                    file_path,
+                });
+            }
+            specs.push(ItemSpec {
+                local_key: format!("track:{id}"),
+                kind: ItemKind::Track,
+                name: row.get(1),
+                artist_names: artists_of_track.remove(&id).unwrap_or_default(),
+                featured_artist_names: featured_of_track.remove(&id).unwrap_or_default(),
+                year: row.get(2),
+                release_type: row.get(5),
+                release_title: Some(row.get(4)),
+                track_number: row.get(6),
+                disc_number: row.get(7),
+                duration_seconds: (duration > 0.0).then_some(duration),
+                content_id,
+            });
+        }
+        self.spawn_content_warmer(pool.clone(), storage_dir, content_hash_jobs);
+
+        Ok(specs)
+    }
+
+    fn cached_content_id_for_media(&self, media_file_id: i64, sha256_hash: &str) -> Option<String> {
+        if let Some((cached_hash, content_id)) = lock(&self.content_cache).get(&media_file_id)
+            && cached_hash == sha256_hash
+        {
+            return Some(content_id.clone());
+        }
+        None
+    }
+
+    fn mark_content_hash_pending(&self, media_file_id: i64) -> bool {
+        lock(&self.content_pending).insert(media_file_id)
+    }
+
+    fn spawn_content_warmer(
+        self: &Arc<Self>,
+        pool: PgPool,
+        storage_dir: String,
+        jobs: Vec<ContentHashJob>,
+    ) {
+        if jobs.is_empty() {
+            return;
+        }
+        let fed = Arc::clone(self);
+        tokio::spawn(async move {
+            let total = jobs.len();
+            let mut stored = 0usize;
+            for job in jobs {
+                let job_storage_dir = storage_dir.clone();
+                let job_file_path = job.file_path.clone();
+                let content_id = tokio::task::spawn_blocking(move || {
+                    audio_content_id(&job_storage_dir, &job_file_path)
+                })
+                .await
+                .ok()
+                .flatten();
+                lock(&fed.content_pending).remove(&job.media_file_id);
+                if let Some(content_id) = content_id {
+                    lock(&fed.content_cache).insert(
+                        job.media_file_id,
+                        (job.sha256_hash.clone(), content_id.clone()),
+                    );
+                    if let Err(err) =
+                        persist_content_id(&pool, job.media_file_id, &job.sha256_hash, &content_id)
+                            .await
+                    {
+                        tracing::warn!(
+                            media_file_id = job.media_file_id,
+                            "federation content-id cache write failed: {err:#}"
+                        );
+                    } else {
+                        stored += 1;
+                    }
+                }
+            }
+            tracing::info!(total, stored, "federation content-id cache warm finished");
+        });
+    }
+
+    /// Live status for the admin page.
+    pub async fn status(&self) -> Value {
+        let guard = self.running.lock().await;
+        let node = match guard.as_ref() {
+            Some(running) => {
+                let service = &running.service;
+                let published = service
+                    .list_local_items()
+                    .await
+                    .map(|items| items.len())
+                    .unwrap_or(0);
+                let peers: Vec<String> = service
+                    .connected_peers()
+                    .iter()
+                    .map(|p| p.to_string())
+                    .collect();
+                json!({
+                    "running": true,
+                    "network": running.network_name,
+                    "endpoint_id": service.endpoint_id().to_string(),
+                    "connected_peers": peers,
+                    "known_contacts": service.known_peers().len(),
+                    "published_items": published,
+                    "transport": self.transport_stats.snapshot(),
+                })
+            }
+            None => json!({ "running": false }),
+        };
+        json!({
+            "node": node,
+            "last_sync": lock(&self.last_sync).clone(),
+            "last_error": lock(&self.last_error).clone(),
+        })
+    }
+
+    pub async fn ticket(&self) -> Result<String> {
+        let service = self.service().await?;
+        let ticket = service
+            .ticket()
+            .await
+            .map_err(|err| anyhow::anyhow!("cannot create a ticket: {err}"))?;
+        Ok(ticket.to_string())
+    }
+
+    pub async fn connect(&self, ticket: &str) -> Result<String> {
+        let service = self.service().await?;
+        let ticket: PeerTicket = ticket
+            .trim()
+            .parse()
+            .map_err(|err| anyhow::anyhow!("malformed ticket: {err}"))?;
+        let peer = service
+            .connect(ticket)
+            .await
+            .map_err(|err| anyhow::anyhow!("connect failed: {err}"))?;
+        Ok(peer.to_string())
+    }
+
+    pub async fn fed_device_status(
+        &self,
+        user_id: i64,
+        user_name: &str,
+    ) -> Result<devices::FedDeviceStatus> {
+        let pool = self.pool().await?;
+        devices::status(&pool, user_id, user_name).await
+    }
+
+    pub async fn fed_device_invite(&self, user_id: i64, user_name: &str) -> Result<String> {
+        let service = self.service().await?;
+        let pool = self.pool().await?;
+        devices::create_invite(&pool, service, user_id, user_name).await
+    }
+
+    pub async fn fed_device_connect(
+        &self,
+        user_id: i64,
+        user_name: &str,
+        invite: &str,
+    ) -> Result<String> {
+        let network_id = devices::invite_network_id(invite)?;
+        {
+            let guard = self.running.lock().await;
+            let Some(running) = guard.as_ref() else {
+                anyhow::bail!("federation is not running");
+            };
+            let expected = NetworkId::from_name(&running.network_name);
+            anyhow::ensure!(
+                network_id == expected,
+                "device invite belongs to a different federation network"
+            );
+        }
+        let service = self.service().await?;
+        let pool = self.pool().await?;
+        devices::connect_invite(
+            &pool,
+            service,
+            crate::player::PlayerDeviceHub::shared(),
+            Arc::clone(&self.transport_stats),
+            user_id,
+            user_name,
+            invite,
+        )
+        .await
+    }
+
+    pub async fn fed_device_answer_pairing(
+        &self,
+        user_id: i64,
+        request_id: &str,
+        accept: bool,
+        use_requester_group: bool,
+    ) -> Result<()> {
+        let pool = self.pool().await?;
+        devices::answer_pairing(&pool, user_id, request_id, accept, use_requester_group).await
+    }
+
+    pub async fn fed_device_revoke(&self, user_id: i64, device_id: &str) -> Result<()> {
+        let pool = self.pool().await?;
+        devices::revoke_device(&pool, user_id, device_id).await
+    }
+
+    pub async fn fed_device_sync_now(&self, user_id: i64) -> Result<()> {
+        let service = self.service().await?;
+        let pool = self.pool().await?;
+        devices::sync_once(
+            &pool,
+            service,
+            crate::player::PlayerDeviceHub::shared(),
+            Arc::clone(&self.transport_stats),
+            user_id,
+        )
+        .await
+    }
+
+    pub async fn fed_device_web_command(
+        &self,
+        user_id: i64,
+        target_device_id: &str,
+        command: &str,
+        payload: serde_json::Value,
+        current_state: Option<serde_json::Value>,
+    ) -> Result<serde_json::Value> {
+        let pool = self.pool().await?;
+        devices::record_web_playback_command(
+            &pool,
+            user_id,
+            target_device_id,
+            command,
+            payload,
+            current_state,
+        )
+        .await
+    }
+
+    pub async fn fed_device_web_active_transfer(
+        &self,
+        user_id: i64,
+        target_device_id: &str,
+        previous_device_id: Option<&str>,
+        state: serde_json::Value,
+    ) -> Result<()> {
+        let pool = self.pool().await?;
+        devices::record_web_active_transfer(
+            &pool,
+            user_id,
+            target_device_id,
+            previous_device_id,
+            state,
+        )
+        .await
+    }
+
+    pub async fn fed_device_web_active_takeover(
+        &self,
+        user_id: i64,
+        previous_device_id: &str,
+        state: serde_json::Value,
+    ) -> Result<()> {
+        let pool = self.pool().await?;
+        devices::record_web_active_takeover(&pool, user_id, previous_device_id, state).await
+    }
+}
+
+async fn persist_content_id(
+    pool: &PgPool,
+    media_file_id: i64,
+    sha256_hash: &str,
+    content_id: &str,
+) -> Result<()> {
+    sqlx::query(
+        "INSERT INTO furumusic__federation_content_id_cache
+         (media_file_id, sha256_hash, content_id, updated_at)
+         VALUES ($1, $2, $3, $4)
+         ON CONFLICT (media_file_id) DO UPDATE SET
+            sha256_hash = EXCLUDED.sha256_hash,
+            content_id = EXCLUDED.content_id,
+            updated_at = EXCLUDED.updated_at",
+    )
+    .bind(media_file_id)
+    .bind(sha256_hash)
+    .bind(content_id)
+    .bind(now_iso())
+    .execute(pool)
+    .await?;
+    Ok(())
+}
+
+fn audio_content_id(storage_dir: &str, file_path: &str) -> Option<String> {
+    if storage_dir.trim().is_empty() {
+        return None;
+    }
+    let path = crate::media_paths::resolve_media_file_path(storage_dir, file_path);
+    let mut file = std::fs::File::open(path).ok()?;
+    let mut hasher = blake3::Hasher::new();
+    std::io::copy(&mut file, &mut hasher).ok()?;
+    Some(format!("b3:{}", hasher.finalize().to_hex()))
+}
+
+async fn stop_running(running: Option<Running>) {
+    let Some(running) = running else { return };
+    for task in &running.tasks {
+        task.abort();
+    }
+    if let Err(err) = running.service.shutdown().await {
+        tracing::warn!("federation node shutdown reported an error: {err}");
+    }
+    tracing::info!("federation stopped");
+}

src/federation/serve.rs

@@ -0,0 +1,775 @@
+//! Serve side of the federation wire protocols (audio + catalog), backed by
+//! the PostgreSQL library and the media storage directory. Wire compatible
+//! with the furumi TUI client and any other furumi peer.
+
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+use anyhow::Result;
+pub use music_dht::catalog::CATALOG_ALPN;
+use music_dht::catalog::{
+    CatalogArtist, CatalogArtistPreview, CatalogImageHeader as ImageHeader, CatalogRelease,
+    CatalogRequest, CatalogResponse, CatalogTrack,
+};
+use music_dht::{ByteStream, EndpointId, ItemId, ItemKind, StreamAcceptor, normalize_name};
+use serde::{Deserialize, Serialize};
+use sqlx::PgPool;
+use sqlx::Row as _;
+use tokio::io::{AsyncRead, AsyncReadExt, AsyncSeekExt, AsyncWriteExt};
+
+use super::{TransportStats, record_stream_transport};
+
+/// ALPN of the peer-to-peer audio streaming protocol.
+pub const AUDIO_ALPN: &[u8] = b"furumi-fd/audio/1";
+/// Version of the peer-to-peer audio streaming protocol.
+pub const AUDIO_PROTOCOL_VERSION: u16 = 1;
+
+/// Maximum size of a JSON protocol line (request or response header).
+const MAX_PROTOCOL_LINE: usize = 4096;
+/// Images above this size are skipped rather than transferred.
+const MAX_IMAGE_BYTES: u64 = 16 * 1024 * 1024;
+
+// ---------------------------------------------------------------------------
+// Wire shapes (shared with the furumi TUI client)
+// ---------------------------------------------------------------------------
+
+#[derive(Debug, Deserialize)]
+struct AudioRequest {
+    item_id: String,
+    #[serde(default)]
+    offset: u64,
+    #[serde(default)]
+    want_cover: bool,
+}
+
+#[derive(Debug, Default, Serialize)]
+struct AudioResponseHeader {
+    ok: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    error: Option<String>,
+    mime_type: String,
+    total_size: u64,
+    offset: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    metadata: Option<TrackMetadata>,
+    cover_size: u64,
+    cover_mime: String,
+    artist_image_size: u64,
+    artist_image_mime: String,
+}
+
+#[derive(Debug, Clone, Default, Serialize)]
+struct TrackMetadata {
+    title: String,
+    artists: Vec<String>,
+    featured_artists: Vec<String>,
+    album_artists: Vec<String>,
+    release_title: String,
+    release_type: Option<String>,
+    year: Option<i32>,
+    track_number: Option<i32>,
+    disc_number: Option<i32>,
+}
+
+// ---------------------------------------------------------------------------
+// Framing helpers
+// ---------------------------------------------------------------------------
+
+fn hex_encode(bytes: &[u8]) -> String {
+    bytes.iter().map(|b| format!("{b:02x}")).collect()
+}
+
+fn hex_decode_item_id(value: &str) -> Option<ItemId> {
+    if value.len() != 64 {
+        return None;
+    }
+    let mut bytes = [0u8; 32];
+    for (i, byte) in bytes.iter_mut().enumerate() {
+        *byte = u8::from_str_radix(&value[i * 2..i * 2 + 2], 16).ok()?;
+    }
+    Some(ItemId::from_bytes(bytes))
+}
+
+async fn read_line<R: AsyncRead + Unpin>(reader: &mut R) -> Result<Vec<u8>> {
+    let mut line = Vec::new();
+    let mut byte = [0u8; 1];
+    loop {
+        let n = reader.read(&mut byte).await?;
+        if n == 0 {
+            anyhow::bail!("stream ended before the protocol line was complete");
+        }
+        if byte[0] == b'\n' {
+            return Ok(line);
+        }
+        line.push(byte[0]);
+        if line.len() > MAX_PROTOCOL_LINE {
+            anyhow::bail!("protocol line exceeds {MAX_PROTOCOL_LINE} bytes");
+        }
+    }
+}
+
+async fn write_line<W: AsyncWriteExt + Unpin>(
+    writer: &mut W,
+    value: &impl Serialize,
+) -> Result<()> {
+    let mut line = serde_json::to_vec(value)?;
+    line.push(b'\n');
+    writer.write_all(&line).await?;
+    Ok(())
+}
+
+fn item_id_of(own: &EndpointId, track_id: i64) -> String {
+    hex_encode(ItemId::derive(own, ItemKind::Track, &format!("track:{track_id}")).as_bytes())
+}
+
+fn resolve_media_path(storage_dir: &str, file_path: &str) -> PathBuf {
+    crate::media_paths::resolve_media_file_path(storage_dir, file_path)
+}
+
+fn guess_mime(path: &Path) -> &'static str {
+    match path
+        .extension()
+        .and_then(|e| e.to_str())
+        .unwrap_or_default()
+        .to_ascii_lowercase()
+        .as_str()
+    {
+        "mp3" => "audio/mpeg",
+        "flac" => "audio/flac",
+        "ogg" | "oga" => "audio/ogg",
+        "opus" => "audio/opus",
+        "wav" => "audio/wav",
+        "m4a" | "mp4" | "alac" => "audio/mp4",
+        "aac" => "audio/aac",
+        "aiff" | "aif" => "audio/aiff",
+        _ => "application/octet-stream",
+    }
+}
+
+/// Reads an image media file from disk, bounded by [`MAX_IMAGE_BYTES`].
+async fn read_image(
+    storage_dir: &str,
+    media: Option<(String, String)>,
+) -> Option<(Vec<u8>, String)> {
+    let (file_path, mime) = media?;
+    let path = resolve_media_path(storage_dir, &file_path);
+    let size = tokio::fs::metadata(&path).await.ok()?.len();
+    if size == 0 || size > MAX_IMAGE_BYTES {
+        return None;
+    }
+    let bytes = tokio::fs::read(&path).await.ok()?;
+    let mime = if mime.trim().is_empty() {
+        "image/jpeg".to_string()
+    } else {
+        mime
+    };
+    Some((bytes, mime))
+}
+
+// ---------------------------------------------------------------------------
+// Library lookups (PostgreSQL)
+// ---------------------------------------------------------------------------
+
+/// Finds the visible track whose derived DHT item id matches `item_id`.
+async fn resolve_track_id(pool: &PgPool, own: &EndpointId, item_id: ItemId) -> Result<Option<i64>> {
+    let rows = sqlx::query(
+        "SELECT t.id FROM furumusic__track t
+         JOIN furumusic__release r ON r.id = t.release_id
+         WHERE t.is_hidden = false AND r.is_hidden = false",
+    )
+    .fetch_all(pool)
+    .await?;
+    for row in rows {
+        let track_id: i64 = row.get(0);
+        if ItemId::derive(own, ItemKind::Track, &format!("track:{track_id}")) == item_id {
+            return Ok(Some(track_id));
+        }
+    }
+    Ok(None)
+}
+
+/// (file_path, mime_type) of the track's audio media file.
+async fn track_audio_file(pool: &PgPool, track_id: i64) -> Result<Option<(String, String)>> {
+    let row = sqlx::query(
+        "SELECT m.file_path, m.mime_type FROM furumusic__track t
+         JOIN furumusic__media_file m ON m.id = t.audio_file_id
+         WHERE t.id = $1",
+    )
+    .bind(track_id)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| (row.get(0), row.get(1))))
+}
+
+/// Track cover (falling back to the release cover) as (file_path, mime).
+async fn track_cover_file(pool: &PgPool, track_id: i64) -> Result<Option<(String, String)>> {
+    let row = sqlx::query(
+        "SELECT m.file_path, m.mime_type FROM furumusic__track t
+         JOIN furumusic__release r ON r.id = t.release_id
+         JOIN furumusic__media_file m ON m.id = COALESCE(t.cover_file_id, r.cover_file_id)
+         WHERE t.id = $1",
+    )
+    .bind(track_id)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| (row.get(0), row.get(1))))
+}
+
+/// The main artist's image of a track as (file_path, mime).
+async fn track_artist_image_file(pool: &PgPool, track_id: i64) -> Result<Option<(String, String)>> {
+    let row = sqlx::query(
+        "SELECT m.file_path, m.mime_type FROM furumusic__track_artist ta
+         JOIN furumusic__artist a ON a.id = ta.artist_id
+         JOIN furumusic__media_file m ON m.id = a.image_file_id
+         WHERE ta.track_id = $1 AND ta.role = 'main'
+         ORDER BY ta.position LIMIT 1",
+    )
+    .bind(track_id)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| (row.get(0), row.get(1))))
+}
+
+async fn track_catalog_artist_names(
+    pool: &PgPool,
+    track_id: i64,
+) -> Result<(Vec<String>, Vec<String>)> {
+    let mut artists = Vec::new();
+    let mut featured = Vec::new();
+    let rows = sqlx::query(
+        "SELECT a.name, ta.role FROM furumusic__track_artist ta
+         JOIN furumusic__artist a ON a.id = ta.artist_id
+         WHERE ta.track_id = $1 ORDER BY ta.position",
+    )
+    .bind(track_id)
+    .fetch_all(pool)
+    .await?;
+    for row in rows {
+        let name: String = row.get(0);
+        match row.get::<String, _>(1).as_str() {
+            "featuring" => featured.push(name),
+            "main" => artists.push(name),
+            _ => {}
+        }
+    }
+    Ok((artists, featured))
+}
+
+async fn track_metadata(pool: &PgPool, track_id: i64) -> Result<Option<TrackMetadata>> {
+    let Some(track) = sqlx::query(
+        "SELECT t.title, t.track_number, t.disc_number, COALESCE(t.year, r.year),
+                t.release_id, r.title, r.release_type
+         FROM furumusic__track t
+         JOIN furumusic__release r ON r.id = t.release_id
+         WHERE t.id = $1",
+    )
+    .bind(track_id)
+    .fetch_optional(pool)
+    .await?
+    else {
+        return Ok(None);
+    };
+    let release_id: i64 = track.get(4);
+
+    let mut artists = Vec::new();
+    let mut featured = Vec::new();
+    let artist_rows = sqlx::query(
+        "SELECT a.name, ta.role FROM furumusic__track_artist ta
+         JOIN furumusic__artist a ON a.id = ta.artist_id
+         WHERE ta.track_id = $1 ORDER BY ta.position",
+    )
+    .bind(track_id)
+    .fetch_all(pool)
+    .await?;
+    for row in artist_rows {
+        let name: String = row.get(0);
+        match row.get::<String, _>(1).as_str() {
+            "featuring" => featured.push(name),
+            "main" => artists.push(name),
+            _ => {}
+        }
+    }
+    let album_artists: Vec<String> = sqlx::query(
+        "SELECT a.name FROM furumusic__release_artist ra
+         JOIN furumusic__artist a ON a.id = ra.artist_id
+         WHERE ra.release_id = $1 ORDER BY ra.position",
+    )
+    .bind(release_id)
+    .fetch_all(pool)
+    .await?
+    .into_iter()
+    .map(|row| row.get(0))
+    .collect();
+
+    Ok(Some(TrackMetadata {
+        title: track.get(0),
+        artists,
+        featured_artists: featured,
+        album_artists,
+        release_title: track.get(5),
+        release_type: Some(track.get(6)),
+        year: track.get(3),
+        track_number: track.get(1),
+        disc_number: track.get(2),
+    }))
+}
+
+// ---------------------------------------------------------------------------
+// Audio protocol
+// ---------------------------------------------------------------------------
+
+/// Runs the audio accept loop until the acceptor closes. Every visible
+/// track of the library is streamable by every peer of the network.
+pub async fn serve_audio(
+    mut acceptor: StreamAcceptor,
+    pool: PgPool,
+    storage_dir: String,
+    own: EndpointId,
+    transport_stats: Arc<TransportStats>,
+) {
+    while let Some(stream) = acceptor.accept().await {
+        let pool = pool.clone();
+        let storage_dir = storage_dir.clone();
+        let transport_stats = Arc::clone(&transport_stats);
+        tokio::spawn(async move {
+            let peer = stream.peer_id;
+            if let Err(err) = serve_audio_one(stream, pool, storage_dir, own, transport_stats).await
+            {
+                tracing::warn!(peer = %peer, "federation audio stream failed: {err:#}");
+            }
+        });
+    }
+}
+
+async fn serve_audio_one(
+    mut stream: ByteStream,
+    pool: PgPool,
+    storage_dir: String,
+    own: EndpointId,
+    transport_stats: Arc<TransportStats>,
+) -> Result<()> {
+    record_stream_transport(&transport_stats, "audio", "inbound", "open", &stream);
+    let request: AudioRequest = serde_json::from_slice(&read_line(&mut stream.recv).await?)?;
+    tracing::info!(
+        peer = %stream.peer_id,
+        item = %request.item_id,
+        offset = request.offset,
+        "federation peer requested audio"
+    );
+
+    let track_id = match hex_decode_item_id(&request.item_id) {
+        Some(item_id) => match resolve_track_id(&pool, &own, item_id).await {
+            Ok(Some(track_id)) => track_id,
+            Ok(None) => return refuse_audio(stream, "track not found in the library").await,
+            Err(err) => {
+                return refuse_audio(stream, &format!("library lookup failed: {err:#}")).await;
+            }
+        },
+        None => return refuse_audio(stream, "malformed item_id").await,
+    };
+
+    let Some((file_path, mime_type)) = track_audio_file(&pool, track_id).await? else {
+        return refuse_audio(stream, "audio file record is missing").await;
+    };
+    let path = resolve_media_path(&storage_dir, &file_path);
+    let mut file = match tokio::fs::File::open(&path).await {
+        Ok(file) => file,
+        Err(err) => {
+            return refuse_audio(stream, &format!("audio file is not readable: {err}")).await;
+        }
+    };
+    let total_size = file.metadata().await?.len();
+    let offset = request.offset.min(total_size);
+    if offset > 0 {
+        file.seek(std::io::SeekFrom::Start(offset)).await?;
+    }
+
+    let metadata = match track_metadata(&pool, track_id).await {
+        Ok(metadata) => metadata,
+        Err(err) => {
+            tracing::warn!(track_id, "federation metadata lookup failed: {err:#}");
+            None
+        }
+    };
+    let (cover, artist_image) = if request.want_cover {
+        (
+            read_image(
+                &storage_dir,
+                track_cover_file(&pool, track_id).await.ok().flatten(),
+            )
+            .await,
+            read_image(
+                &storage_dir,
+                track_artist_image_file(&pool, track_id)
+                    .await
+                    .ok()
+                    .flatten(),
+            )
+            .await,
+        )
+    } else {
+        (None, None)
+    };
+
+    let mime_type = if mime_type.trim().is_empty() {
+        guess_mime(&path).to_string()
+    } else {
+        mime_type
+    };
+    write_line(
+        &mut stream.send,
+        &AudioResponseHeader {
+            ok: true,
+            error: None,
+            mime_type,
+            total_size,
+            offset,
+            metadata,
+            cover_size: cover.as_ref().map_or(0, |(bytes, _)| bytes.len() as u64),
+            cover_mime: cover
+                .as_ref()
+                .map(|(_, mime)| mime.clone())
+                .unwrap_or_default(),
+            artist_image_size: artist_image
+                .as_ref()
+                .map_or(0, |(bytes, _)| bytes.len() as u64),
+            artist_image_mime: artist_image
+                .as_ref()
+                .map(|(_, mime)| mime.clone())
+                .unwrap_or_default(),
+        },
+    )
+    .await?;
+    if let Some((bytes, _)) = &cover {
+        stream.send.write_all(bytes).await?;
+    }
+    if let Some((bytes, _)) = &artist_image {
+        stream.send.write_all(bytes).await?;
+    }
+    tokio::io::copy(&mut file, &mut stream.send).await?;
+    stream.send.finish()?;
+    // Wait until the peer read everything before dropping the stream,
+    // otherwise the tail of the file is lost.
+    let _ = stream.send.stopped().await;
+    record_stream_transport(&transport_stats, "audio", "inbound", "done", &stream);
+    Ok(())
+}
+
+async fn refuse_audio(mut stream: ByteStream, message: &str) -> Result<()> {
+    write_line(
+        &mut stream.send,
+        &AudioResponseHeader {
+            ok: false,
+            error: Some(message.to_string()),
+            ..AudioResponseHeader::default()
+        },
+    )
+    .await?;
+    stream.send.finish()?;
+    let _ = stream.send.stopped().await;
+    anyhow::bail!("refused audio request: {message}");
+}
+
+// ---------------------------------------------------------------------------
+// Catalog protocol
+// ---------------------------------------------------------------------------
+
+/// Runs the catalog accept loop until the acceptor closes.
+pub async fn serve_catalog(
+    mut acceptor: StreamAcceptor,
+    pool: PgPool,
+    storage_dir: String,
+    own: EndpointId,
+    transport_stats: Arc<TransportStats>,
+) {
+    while let Some(stream) = acceptor.accept().await {
+        let pool = pool.clone();
+        let storage_dir = storage_dir.clone();
+        let transport_stats = Arc::clone(&transport_stats);
+        tokio::spawn(async move {
+            let peer = stream.peer_id;
+            if let Err(err) =
+                serve_catalog_one(stream, pool, storage_dir, own, transport_stats).await
+            {
+                tracing::warn!(peer = %peer, "federation catalog request failed: {err:#}");
+            }
+        });
+    }
+}
+
+async fn serve_catalog_one(
+    mut stream: ByteStream,
+    pool: PgPool,
+    storage_dir: String,
+    own: EndpointId,
+    transport_stats: Arc<TransportStats>,
+) -> Result<()> {
+    record_stream_transport(&transport_stats, "catalog", "inbound", "open", &stream);
+    let request: CatalogRequest = serde_json::from_slice(&read_line(&mut stream.recv).await?)?;
+    tracing::info!(
+        peer = %stream.peer_id,
+        artist = %request.artist,
+        want = request.want.as_deref().unwrap_or("catalog"),
+        "federation peer requested a catalog"
+    );
+
+    match request.want.as_deref() {
+        None | Some("catalog") => {
+            let response = match build_catalog(&pool, &own, &request.artist).await {
+                Ok(response) => response,
+                Err(err) => CatalogResponse {
+                    ok: false,
+                    error: Some(format!("catalog lookup failed: {err:#}")),
+                    ..CatalogResponse::default()
+                },
+            };
+            stream
+                .send
+                .write_all(&serde_json::to_vec(&response)?)
+                .await?;
+        }
+        Some("artists") => {
+            let cursor = request.cursor.clone();
+            let limit = request.limit.unwrap_or(64).clamp(1, 200);
+            let response = match build_artist_slice(&pool, cursor, limit).await {
+                Ok(response) => response,
+                Err(err) => CatalogResponse {
+                    ok: false,
+                    error: Some(format!("artist slice lookup failed: {err:#}")),
+                    ..CatalogResponse::default()
+                },
+            };
+            stream
+                .send
+                .write_all(&serde_json::to_vec(&response)?)
+                .await?;
+        }
+        Some(want @ ("artist_image" | "release_cover")) => {
+            let media = if want == "release_cover" {
+                release_cover_by_names(
+                    &pool,
+                    &request.artist,
+                    request.release.as_deref().unwrap_or_default(),
+                )
+                .await?
+            } else {
+                artist_image_by_name(&pool, &request.artist).await?
+            };
+            let image = read_image(&storage_dir, media).await;
+            let header = match &image {
+                Some((bytes, mime)) => ImageHeader {
+                    ok: true,
+                    error: None,
+                    mime_type: mime.clone(),
+                    size: bytes.len() as u64,
+                },
+                None => ImageHeader {
+                    ok: false,
+                    error: Some("no image".to_string()),
+                    ..ImageHeader::default()
+                },
+            };
+            write_line(&mut stream.send, &header).await?;
+            if let Some((bytes, _)) = &image {
+                stream.send.write_all(bytes).await?;
+            }
+        }
+        Some(other) => {
+            let response = CatalogResponse {
+                ok: false,
+                error: Some(format!("unknown request kind '{other}'")),
+                ..CatalogResponse::default()
+            };
+            stream
+                .send
+                .write_all(&serde_json::to_vec(&response)?)
+                .await?;
+        }
+    }
+    stream.send.finish()?;
+    let _ = stream.send.stopped().await;
+    record_stream_transport(&transport_stats, "catalog", "inbound", "done", &stream);
+    Ok(())
+}
+
+async fn build_catalog(pool: &PgPool, own: &EndpointId, artist: &str) -> Result<CatalogResponse> {
+    let Some(artist_row) = sqlx::query(
+        "SELECT id, name FROM furumusic__artist
+         WHERE LOWER(name) = LOWER($1) AND is_hidden = false
+         LIMIT 1",
+    )
+    .bind(artist)
+    .fetch_optional(pool)
+    .await?
+    else {
+        return Ok(CatalogResponse {
+            ok: false,
+            error: Some("artist not found in the library".to_string()),
+            ..CatalogResponse::default()
+        });
+    };
+    let artist_id: i64 = artist_row.get(0);
+
+    let release_rows = sqlx::query(
+        "SELECT r.id, r.title, r.release_type, r.year
+         FROM furumusic__release r
+         JOIN furumusic__release_artist ra ON ra.release_id = r.id
+         WHERE ra.artist_id = $1 AND r.is_hidden = false
+         ORDER BY r.year NULLS LAST, r.title",
+    )
+    .bind(artist_id)
+    .fetch_all(pool)
+    .await?;
+    let mut releases = Vec::new();
+    for release_row in release_rows {
+        let release_id: i64 = release_row.get(0);
+        let track_rows = sqlx::query(
+            "SELECT t.id, t.title, t.track_number, t.disc_number, t.duration_seconds,
+                    c.content_id
+             FROM furumusic__track t
+             JOIN furumusic__media_file m ON m.id = t.audio_file_id
+             LEFT JOIN furumusic__federation_content_id_cache c
+                    ON c.media_file_id = m.id AND c.sha256_hash = m.sha256_hash
+             WHERE t.release_id = $1 AND t.is_hidden = false
+             ORDER BY t.disc_number NULLS FIRST, t.track_number NULLS LAST, t.title",
+        )
+        .bind(release_id)
+        .fetch_all(pool)
+        .await?;
+        let mut tracks = Vec::with_capacity(track_rows.len());
+        for row in track_rows {
+            let track_id: i64 = row.get(0);
+            let duration: f64 = row.get(4);
+            let (artists, featured_artists) = track_catalog_artist_names(pool, track_id).await?;
+            tracks.push(CatalogTrack {
+                title: row.get(1),
+                artists,
+                featured_artists,
+                track_number: row.get(2),
+                disc_number: row.get(3),
+                duration_seconds: (duration > 0.0).then_some(duration),
+                content_id: row.get(5),
+                item_id: item_id_of(own, track_id),
+            });
+        }
+        releases.push(CatalogRelease {
+            title: release_row.get(1),
+            release_type: release_row.get(2),
+            year: release_row.get(3),
+            tracks,
+        });
+    }
+
+    Ok(CatalogResponse {
+        ok: true,
+        artist: Some(CatalogArtist {
+            name: artist_row.get(1),
+            releases,
+            appears_on: Vec::new(),
+        }),
+        ..CatalogResponse::default()
+    })
+}
+
+async fn build_artist_slice(
+    pool: &PgPool,
+    cursor: Option<String>,
+    limit: usize,
+) -> Result<CatalogResponse> {
+    let offset = cursor
+        .as_deref()
+        .and_then(|value| value.parse::<i64>().ok())
+        .unwrap_or(0)
+        .max(0);
+    let rows = sqlx::query(
+        r#"SELECT a.name::text AS name,
+                  mf.file_path::text AS image_path,
+                  COALESCE(s.release_count, 0)::bigint AS release_count,
+                  COALESCE(s.track_count, 0)::bigint AS track_count
+           FROM furumusic__artist a
+           LEFT JOIN furumusic__media_file mf ON mf.id = a.image_file_id
+           LEFT JOIN (
+               SELECT appearance.artist_id,
+                      COUNT(DISTINCT appearance.release_id) FILTER (WHERE appearance.is_primary_release_artist) AS release_count,
+                      COUNT(DISTINCT appearance.track_id) AS track_count
+                 FROM (
+                        SELECT ta.artist_id,
+                               t.id AS track_id,
+                               r.id AS release_id,
+                               primary_release.artist_id IS NOT NULL AS is_primary_release_artist
+                          FROM furumusic__track_artist ta
+                          JOIN furumusic__track t ON t.id = ta.track_id AND t.is_hidden = false
+                          JOIN furumusic__release r ON r.id = t.release_id AND r.is_hidden = false
+                          LEFT JOIN furumusic__release_artist primary_release
+                            ON primary_release.release_id = r.id
+                           AND primary_release.artist_id = ta.artist_id
+                           AND primary_release.position = 0
+                      ) appearance
+                GROUP BY appearance.artist_id
+           ) s ON s.artist_id = a.id
+           WHERE a.is_hidden = false
+             AND COALESCE(s.track_count, 0) > 0
+           ORDER BY (COALESCE(s.release_count, 0) > 0) DESC,
+                    COALESCE(s.release_count, 0) DESC,
+                    COALESCE(s.track_count, 0) DESC,
+                    a.name_sort
+           LIMIT $1 OFFSET $2"#,
+    )
+    .bind(limit as i64 + 1)
+    .bind(offset)
+    .fetch_all(pool)
+    .await?;
+
+    let mut artists = Vec::with_capacity(rows.len().min(limit));
+    let has_more = rows.len() > limit;
+    for row in rows.into_iter().take(limit) {
+        let name: String = row.get(0);
+        artists.push(CatalogArtistPreview {
+            artist_key: normalize_name(&name),
+            name,
+            image_path: row.get(1),
+            release_count: row.get(2),
+            track_count: row.get(3),
+        });
+    }
+    let next_cursor = has_more.then(|| (offset + artists.len() as i64).to_string());
+    Ok(CatalogResponse {
+        ok: true,
+        artists,
+        next_cursor,
+        ..CatalogResponse::default()
+    })
+}
+
+async fn artist_image_by_name(pool: &PgPool, artist: &str) -> Result<Option<(String, String)>> {
+    let row = sqlx::query(
+        "SELECT m.file_path, m.mime_type FROM furumusic__artist a
+         JOIN furumusic__media_file m ON m.id = a.image_file_id
+         WHERE LOWER(a.name) = LOWER($1) AND a.is_hidden = false
+         LIMIT 1",
+    )
+    .bind(artist)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| (row.get(0), row.get(1))))
+}
+
+async fn release_cover_by_names(
+    pool: &PgPool,
+    artist: &str,
+    release: &str,
+) -> Result<Option<(String, String)>> {
+    let row = sqlx::query(
+        "SELECT m.file_path, m.mime_type FROM furumusic__release r
+         JOIN furumusic__release_artist ra ON ra.release_id = r.id
+         JOIN furumusic__artist a ON a.id = ra.artist_id
+         JOIN furumusic__media_file m ON m.id = r.cover_file_id
+         WHERE LOWER(a.name) = LOWER($1) AND LOWER(r.title) = LOWER($2)
+         LIMIT 1",
+    )
+    .bind(artist)
+    .bind(release)
+    .fetch_optional(pool)
+    .await?;
+    Ok(row.map(|row| (row.get(0), row.get(1))))
+}

src/federation/storage.rs

@@ -0,0 +1,349 @@
+use std::str::FromStr;
+
+use async_trait::async_trait;
+use music_dht::{
+    DhtKey, EndpointId, LibraryItem, MAX_RECORDS_PER_RESPONSE, MusicDhtError, MusicDhtStorage,
+    NodeContact, NodeId, SecretKey, StoreDecision, StoredRecord, decide_store,
+};
+use sqlx::{PgPool, Row as _};
+
+const IDENTITY_NAME: &str = "default";
+
+const SCHEMA: &[&str] = &[
+    "CREATE TABLE IF NOT EXISTS furumusic__federation_identity (
+        name        TEXT PRIMARY KEY,
+        secret_key  BYTEA NOT NULL,
+        created_at  TEXT NOT NULL,
+        updated_at  TEXT NOT NULL
+    )",
+    "CREATE TABLE IF NOT EXISTS furumusic__federation_local_item (
+        id              BYTEA PRIMARY KEY,
+        normalized_name TEXT NOT NULL,
+        revision        BIGINT NOT NULL,
+        deleted         BOOLEAN NOT NULL DEFAULT false,
+        updated_at_ms   BIGINT NOT NULL,
+        payload         BYTEA NOT NULL
+    )",
+    "CREATE INDEX IF NOT EXISTS idx_furumusic_federation_local_item_normalized_name
+        ON furumusic__federation_local_item(normalized_name)",
+    "CREATE TABLE IF NOT EXISTS furumusic__federation_dht_record (
+        dht_key          BYTEA NOT NULL,
+        item_id          BYTEA NOT NULL,
+        owner_peer_id    TEXT NOT NULL,
+        payload          BYTEA NOT NULL,
+        revision         BIGINT NOT NULL,
+        deleted          BOOLEAN NOT NULL,
+        expires_at_ms    BIGINT NOT NULL,
+        PRIMARY KEY (dht_key, item_id, owner_peer_id)
+    )",
+    "CREATE INDEX IF NOT EXISTS idx_furumusic_federation_dht_record_expires_at
+        ON furumusic__federation_dht_record(expires_at_ms)",
+    "CREATE TABLE IF NOT EXISTS furumusic__federation_known_peer (
+        peer_id       TEXT PRIMARY KEY,
+        node_id       BYTEA NOT NULL,
+        ticket        TEXT NOT NULL,
+        last_seen_ms  BIGINT NOT NULL
+    )",
+    "CREATE TABLE IF NOT EXISTS furumusic__federation_content_id_cache (
+        media_file_id  BIGINT PRIMARY KEY,
+        sha256_hash    TEXT NOT NULL,
+        content_id     TEXT NOT NULL,
+        updated_at     TEXT NOT NULL
+    )",
+    "CREATE INDEX IF NOT EXISTS idx_furumusic_federation_content_id_cache_content_id
+        ON furumusic__federation_content_id_cache(content_id)",
+];
+
+#[derive(Debug, Clone)]
+pub struct PostgresFederationStorage {
+    pool: PgPool,
+}
+
+impl PostgresFederationStorage {
+    pub async fn new(pool: PgPool) -> music_dht::Result<Self> {
+        let storage = Self { pool };
+        storage.ensure_schema().await?;
+        Ok(storage)
+    }
+
+    pub async fn load_or_create_secret_key(&self) -> music_dht::Result<SecretKey> {
+        if let Some(bytes) = sqlx::query_scalar::<_, Vec<u8>>(
+            "SELECT secret_key FROM furumusic__federation_identity WHERE name = $1",
+        )
+        .bind(IDENTITY_NAME)
+        .fetch_optional(&self.pool)
+        .await
+        .map_err(db_error)?
+        {
+            return secret_from_bytes(bytes);
+        }
+
+        let key = SecretKey::generate();
+        let key_bytes = key.to_bytes();
+        let now = now_iso();
+        let inserted = sqlx::query(
+            "INSERT INTO furumusic__federation_identity
+             (name, secret_key, created_at, updated_at)
+             VALUES ($1, $2, $3, $4)
+             ON CONFLICT (name) DO NOTHING",
+        )
+        .bind(IDENTITY_NAME)
+        .bind(key_bytes.as_slice())
+        .bind(&now)
+        .bind(&now)
+        .execute(&self.pool)
+        .await
+        .map_err(db_error)?
+        .rows_affected();
+        if inserted == 1 {
+            return Ok(key);
+        }
+
+        let bytes = sqlx::query_scalar::<_, Vec<u8>>(
+            "SELECT secret_key FROM furumusic__federation_identity WHERE name = $1",
+        )
+        .bind(IDENTITY_NAME)
+        .fetch_one(&self.pool)
+        .await
+        .map_err(db_error)?;
+        secret_from_bytes(bytes)
+    }
+
+    async fn ensure_schema(&self) -> music_dht::Result<()> {
+        for sql in SCHEMA {
+            sqlx::query(sql)
+                .execute(&self.pool)
+                .await
+                .map_err(db_error)?;
+        }
+        Ok(())
+    }
+}
+
+#[async_trait]
+impl MusicDhtStorage for PostgresFederationStorage {
+    async fn upsert_local_item(&self, item: &LibraryItem) -> music_dht::Result<()> {
+        let payload = postcard::to_stdvec(item).map_err(db_error)?;
+        sqlx::query(
+            "INSERT INTO furumusic__federation_local_item
+             (id, normalized_name, revision, deleted, updated_at_ms, payload)
+             VALUES ($1, $2, $3, $4, $5, $6)
+             ON CONFLICT (id) DO UPDATE SET
+                normalized_name = EXCLUDED.normalized_name,
+                revision = EXCLUDED.revision,
+                deleted = EXCLUDED.deleted,
+                updated_at_ms = EXCLUDED.updated_at_ms,
+                payload = EXCLUDED.payload",
+        )
+        .bind(item.id.as_bytes().as_slice())
+        .bind(&item.normalized_name)
+        .bind(item.revision as i64)
+        .bind(item.deleted)
+        .bind(item.updated_at_ms as i64)
+        .bind(payload)
+        .execute(&self.pool)
+        .await
+        .map_err(db_error)?;
+        Ok(())
+    }
+
+    async fn list_local_items(&self, include_deleted: bool) -> music_dht::Result<Vec<LibraryItem>> {
+        let rows = sqlx::query(
+            "SELECT payload
+             FROM furumusic__federation_local_item
+             WHERE $1 OR deleted = false
+             ORDER BY normalized_name",
+        )
+        .bind(include_deleted)
+        .fetch_all(&self.pool)
+        .await
+        .map_err(db_error)?;
+        Ok(rows
+            .into_iter()
+            .filter_map(|row| postcard::from_bytes::<LibraryItem>(&row.get::<Vec<u8>, _>(0)).ok())
+            .collect())
+    }
+
+    async fn store_dht_record(&self, key: DhtKey, record: StoredRecord) -> music_dht::Result<bool> {
+        let mut conn = self.pool.acquire().await.map_err(db_error)?;
+        store_record_in_conn(&mut conn, &key, &record).await
+    }
+
+    async fn store_dht_records(
+        &self,
+        entries: Vec<(DhtKey, StoredRecord)>,
+    ) -> music_dht::Result<Vec<bool>> {
+        let mut tx = self.pool.begin().await.map_err(db_error)?;
+        let mut stored = Vec::with_capacity(entries.len());
+        for (key, record) in &entries {
+            stored.push(store_record_in_conn(&mut tx, key, record).await?);
+        }
+        tx.commit().await.map_err(db_error)?;
+        Ok(stored)
+    }
+
+    async fn dht_records_by_key(
+        &self,
+        key: DhtKey,
+        now_ms: u64,
+    ) -> music_dht::Result<Vec<StoredRecord>> {
+        let rows = sqlx::query(
+            "SELECT payload
+             FROM furumusic__federation_dht_record
+             WHERE dht_key = $1 AND expires_at_ms > $2
+             ORDER BY expires_at_ms DESC, item_id
+             LIMIT $3",
+        )
+        .bind(key.as_bytes().as_slice())
+        .bind(now_ms as i64)
+        .bind(MAX_RECORDS_PER_RESPONSE as i64)
+        .fetch_all(&self.pool)
+        .await
+        .map_err(db_error)?;
+        Ok(rows
+            .into_iter()
+            .filter_map(|row| postcard::from_bytes::<StoredRecord>(&row.get::<Vec<u8>, _>(0)).ok())
+            .collect())
+    }
+
+    async fn delete_expired_records(&self, now_ms: u64) -> music_dht::Result<usize> {
+        let result =
+            sqlx::query("DELETE FROM furumusic__federation_dht_record WHERE expires_at_ms <= $1")
+                .bind(now_ms as i64)
+                .execute(&self.pool)
+                .await
+                .map_err(db_error)?;
+        Ok(result.rows_affected() as usize)
+    }
+
+    async fn upsert_known_peer(&self, contact: &NodeContact) -> music_dht::Result<()> {
+        sqlx::query(
+            "INSERT INTO furumusic__federation_known_peer
+             (peer_id, node_id, ticket, last_seen_ms)
+             VALUES ($1, $2, $3, $4)
+             ON CONFLICT (peer_id) DO UPDATE SET
+                node_id = EXCLUDED.node_id,
+                ticket = EXCLUDED.ticket,
+                last_seen_ms = EXCLUDED.last_seen_ms",
+        )
+        .bind(contact.peer_id.to_string())
+        .bind(contact.node_id.as_bytes().as_slice())
+        .bind(&contact.ticket)
+        .bind(contact.last_seen_ms as i64)
+        .execute(&self.pool)
+        .await
+        .map_err(db_error)?;
+        Ok(())
+    }
+
+    async fn delete_known_peer(&self, peer_id: EndpointId) -> music_dht::Result<()> {
+        sqlx::query("DELETE FROM furumusic__federation_known_peer WHERE peer_id = $1")
+            .bind(peer_id.to_string())
+            .execute(&self.pool)
+            .await
+            .map_err(db_error)?;
+        Ok(())
+    }
+
+    async fn load_known_peers(&self) -> music_dht::Result<Vec<NodeContact>> {
+        let rows = sqlx::query(
+            "SELECT peer_id, node_id, ticket, last_seen_ms
+             FROM furumusic__federation_known_peer",
+        )
+        .fetch_all(&self.pool)
+        .await
+        .map_err(db_error)?;
+        let mut contacts = Vec::new();
+        for row in rows {
+            let peer_id: String = row.get(0);
+            let node_id: Vec<u8> = row.get(1);
+            let ticket: String = row.get(2);
+            let last_seen_ms: i64 = row.get(3);
+            let Ok(peer_id) = EndpointId::from_str(&peer_id) else {
+                continue;
+            };
+            let Ok(node_id) = <[u8; 32]>::try_from(node_id.as_slice()) else {
+                continue;
+            };
+            contacts.push(NodeContact {
+                node_id: NodeId::from_bytes(node_id),
+                peer_id,
+                ticket,
+                last_seen_ms: last_seen_ms as u64,
+            });
+        }
+        Ok(contacts)
+    }
+}
+
+fn now_iso() -> String {
+    chrono::Utc::now().format("%Y-%m-%dT%H:%M:%SZ").to_string()
+}
+
+fn secret_from_bytes(bytes: Vec<u8>) -> music_dht::Result<SecretKey> {
+    let bytes: [u8; 32] = bytes
+        .as_slice()
+        .try_into()
+        .map_err(|_| MusicDhtError::Database("stored federation identity is corrupted".into()))?;
+    Ok(SecretKey::from_bytes(&bytes))
+}
+
+/// Applies one validated record following the revision/tombstone rules.
+/// Returns `true` if the record was written or refreshed. Runs against a
+/// pooled connection or an open transaction.
+async fn store_record_in_conn(
+    conn: &mut sqlx::PgConnection,
+    key: &DhtKey,
+    record: &StoredRecord,
+) -> music_dht::Result<bool> {
+    let existing = sqlx::query(
+        "SELECT revision, deleted, expires_at_ms
+         FROM furumusic__federation_dht_record
+         WHERE dht_key = $1 AND item_id = $2 AND owner_peer_id = $3",
+    )
+    .bind(key.as_bytes().as_slice())
+    .bind(record.item.id.as_bytes().as_slice())
+    .bind(record.item.owner.to_string())
+    .fetch_optional(&mut *conn)
+    .await
+    .map_err(db_error)?
+    .map(|row| {
+        (
+            row.get::<i64, _>(0) as u64,
+            row.get::<bool, _>(1),
+            row.get::<i64, _>(2) as u64,
+        )
+    });
+
+    match decide_store(existing, record) {
+        StoreDecision::Ignore => return Ok(false),
+        StoreDecision::Write | StoreDecision::RefreshExpiry(_) => {}
+    }
+
+    let payload = postcard::to_stdvec(record).map_err(db_error)?;
+    sqlx::query(
+        "INSERT INTO furumusic__federation_dht_record
+         (dht_key, item_id, owner_peer_id, payload, revision, deleted, expires_at_ms)
+         VALUES ($1, $2, $3, $4, $5, $6, $7)
+         ON CONFLICT (dht_key, item_id, owner_peer_id) DO UPDATE SET
+            payload = EXCLUDED.payload,
+            revision = EXCLUDED.revision,
+            deleted = EXCLUDED.deleted,
+            expires_at_ms = EXCLUDED.expires_at_ms",
+    )
+    .bind(key.as_bytes().as_slice())
+    .bind(record.item.id.as_bytes().as_slice())
+    .bind(record.item.owner.to_string())
+    .bind(payload)
+    .bind(record.item.revision as i64)
+    .bind(record.item.deleted)
+    .bind(record.expires_at_ms as i64)
+    .execute(&mut *conn)
+    .await
+    .map_err(db_error)?;
+    Ok(true)
+}
+
+fn db_error(err: impl std::fmt::Display) -> MusicDhtError {
+    MusicDhtError::Database(err.to_string())
+}

src/i18n/phrases.rs

@@ -309,6 +309,7 @@ translations! {
     player_cancel:           "Cancel"                          , "Отмена";
     player_create:           "Create"                          , "Создать";
     player_save:             "Save"                            , "Сохранить";
+    player_done:             "Done"                            , "Готово";
     player_delete:           "Delete"                          , "Удалить";
     player_delete_playlist_confirm: "Delete this playlist?"     , "Удалить этот плейлист?";
     player_rename:           "Rename"                          , "Переименовать";
@@ -373,6 +374,7 @@ translations! {
     player_repeat:           "Repeat"                          , "Повтор";
     player_volume:           "Volume"                          , "Громкость";
     player_appears_on:       "Appears on"                      , "Участвует в";
+    player_top_tracks:       "Popular tracks"                  , "Популярные треки";
     player_albums:           "Albums"                          , "Альбомы";
     player_eps:              "EPs"                             , "EP";
     player_singles:          "Singles"                         , "Синглы";

src/jobs/inbox_discover.rs

@@ -12,6 +12,21 @@ const AUDIO_EXTENSIONS: &[&str] = &[
     "mp3", "flac", "ogg", "opus", "aac", "m4a", "wav", "ape", "wv", "wma", "tta", "aiff", "aif",
 ];
 
+/// How long a `failed` review must stay untouched before discover
+/// automatically requeues it (instead of creating a new row per attempt).
+const FAILED_RETRY_COOLDOWN_SECS: i64 = 3600;
+
+/// Leftover files that are safe to purge from inbox folders that no longer
+/// contain any audio (covers, playlists, rip logs and similar sidecar files).
+const JUNK_EXTENSIONS: &[&str] = &[
+    "jpg", "jpeg", "png", "gif", "webp", "bmp", "m3u", "m3u8", "cue", "log", "txt", "nfo", "sfv",
+    "md5", "accurip", "url", "ini", "pdf",
+];
+const JUNK_FILENAMES: &[&str] = &[".ds_store", "thumbs.db", "desktop.ini"];
+
+/// Junk younger than this is kept — an upload might still be in progress.
+const JUNK_MIN_AGE: std::time::Duration = std::time::Duration::from_secs(24 * 3600);
+
 pub struct InboxDiscoverJob;
 
 #[async_trait::async_trait]
@@ -76,6 +91,10 @@ impl Job for InboxDiscoverJob {
         let mut audio_files = Vec::new();
         collect_audio_files(inbox, &mut audio_files).await?;
 
+        // Purge leftover junk (covers, playlists, logs) from subtrees that no
+        // longer contain audio, so processed uploads don't linger forever.
+        cleanup_inbox_junk(inbox, JUNK_MIN_AGE).await;
+
         log.info(&format!("Found {} audio files in inbox", audio_files.len()));
         if audio_files.is_empty() {
             return Ok(());
@@ -87,6 +106,7 @@ impl Job for InboxDiscoverJob {
         let mut discovered = 0u64;
         let mut skipped_hash = 0u64;
         let mut skipped_existing = 0u64;
+        let mut requeued = 0u64;
 
         for (_folder, files) in &groups {
             for file_path in files {
@@ -94,13 +114,34 @@ impl Job for InboxDiscoverJob {
                     crate::media_paths::path_for_root(&config.agent_inbox_dir, file_path)
                         .unwrap_or_else(|| file_path.to_string_lossy().to_string());
 
-                // Skip if a PendingReview already exists for this path
-                match PendingReview::exists_for_path(&ctx.db, &input_path_str).await {
-                    Ok(true) => {
-                        skipped_existing += 1;
+                // One review row per path: any existing row blocks creating a
+                // new one. A stale "failed" row is requeued in place instead,
+                // so retries don't multiply rows. "rejected" stays rejected.
+                match PendingReview::latest_for_path(&ctx.pool, &input_path_str).await {
+                    Ok(None) => {}
+                    Ok(Some((id, status, updated_at))) => {
+                        if status == "failed" {
+                            let stale = chrono::DateTime::parse_from_rfc3339(&updated_at)
+                                .map(|t| {
+                                    chrono::Utc::now().signed_duration_since(t).num_seconds()
+                                        >= FAILED_RETRY_COOLDOWN_SECS
+                                })
+                                .unwrap_or(true);
+                            if stale {
+                                match PendingReview::requeue_by_ids(&ctx.db, &[id]).await {
+                                    Ok(()) => requeued += 1,
+                                    Err(e) => log.warn(&format!(
+                                        "Failed to requeue review {id} for {input_path_str}: {e}"
+                                    )),
+                                }
+                            } else {
+                                skipped_existing += 1;
+                            }
+                        } else {
+                            skipped_existing += 1;
+                        }
                         continue;
                     }
-                    Ok(false) => {}
                     Err(e) => {
                         log.warn(&format!(
                             "Error checking existing review for {}: {e}",
@@ -215,8 +256,8 @@ impl Job for InboxDiscoverJob {
         }
 
         log.info(&format!(
-            "Discovered {} new files, skipped {} (hash known), skipped {} (already queued)",
-            discovered, skipped_hash, skipped_existing
+            "Discovered {} new files, requeued {} failed, skipped {} (hash known), skipped {} (already tracked)",
+            discovered, requeued, skipped_hash, skipped_existing
         ));
         crate::metrics::record_agent_discover_files(
             audio_files.len() as u64,
@@ -227,7 +268,7 @@ impl Job for InboxDiscoverJob {
 
         // Trigger inbox_process in background if new files were discovered
         // and no orchestrator is already running
-        if discovered > 0 {
+        if discovered + requeued > 0 {
             if crate::jobs::inbox_process::is_orchestrator_running() {
                 log.info(
                     "New files discovered but inbox_process already running, it will pick them up",
@@ -299,3 +340,75 @@ pub fn is_audio_file(name: &str) -> bool {
     let ext = name.rsplit('.').next().unwrap_or("").to_lowercase();
     AUDIO_EXTENSIONS.contains(&ext.as_str())
 }
+
+fn is_junk_file(name: &str) -> bool {
+    let lower = name.to_lowercase();
+    // macOS AppleDouble sidecars ("._track.mp3") and well-known junk names
+    if lower.starts_with("._") || JUNK_FILENAMES.contains(&lower.as_str()) {
+        return true;
+    }
+    let ext = lower.rsplit('.').next().unwrap_or("");
+    JUNK_EXTENSIONS.contains(&ext)
+}
+
+/// Remove leftover sidecar files (covers, playlists, rip logs) from inbox
+/// subtrees that no longer contain any audio, then prune emptied directories.
+///
+/// Junk younger than `min_age` is kept in case an upload is still in
+/// progress, and unknown file types are never touched. Returns `true` when
+/// `dir` still contains something worth keeping (so the caller must not
+/// remove it).
+async fn cleanup_inbox_junk(dir: &Path, min_age: std::time::Duration) -> bool {
+    let mut entries = match tokio::fs::read_dir(dir).await {
+        Ok(e) => e,
+        Err(_) => return true,
+    };
+
+    let mut has_audio = false;
+    let mut keep_other = false;
+    let mut junk: Vec<PathBuf> = Vec::new();
+
+    while let Ok(Some(entry)) = entries.next_entry().await {
+        let name = entry.file_name().to_string_lossy().into_owned();
+        let ft = match entry.file_type().await {
+            Ok(ft) => ft,
+            Err(_) => {
+                keep_other = true;
+                continue;
+            }
+        };
+        if ft.is_dir() {
+            if Box::pin(cleanup_inbox_junk(&entry.path(), min_age)).await {
+                keep_other = true;
+            } else {
+                let _ = tokio::fs::remove_dir(&entry.path()).await;
+            }
+        } else if !name.starts_with('.') && is_audio_file(&name) {
+            // dotfiles are invisible to discovery, so they don't count as audio
+            has_audio = true;
+        } else if is_junk_file(&name) {
+            junk.push(entry.path());
+        } else {
+            keep_other = true;
+        }
+    }
+
+    if has_audio {
+        return true;
+    }
+
+    let mut junk_left = false;
+    for path in junk {
+        let old_enough = tokio::fs::metadata(&path)
+            .await
+            .ok()
+            .and_then(|m| m.modified().ok())
+            .and_then(|t| t.elapsed().ok())
+            .is_some_and(|age| age >= min_age);
+        if !old_enough || tokio::fs::remove_file(&path).await.is_err() {
+            junk_left = true;
+        }
+    }
+
+    keep_other || junk_left
+}

src/jobs/inbox_process.rs

@@ -12,6 +12,11 @@ static ORCHESTRATOR_RUNNING: AtomicBool = AtomicBool::new(false);
 /// PostgreSQL advisory locks use a 64-bit key; this is an arbitrary unique value.
 const ORCHESTRATOR_ADVISORY_LOCK_ID: i64 = 0x4655_5255_4D55_5349; // "FURUMUSI" in hex
 
+/// Maximum number of files sent to the LLM in a single batch call.
+/// Folders with more files are processed in chunks of this size, otherwise
+/// the model's completion window overflows and the JSON response is cut off.
+const MAX_LLM_BATCH_FILES: usize = 20;
+
 /// Check if an orchestrator is currently running (used by inbox_discover to avoid redundant triggers).
 pub fn is_orchestrator_running() -> bool {
     ORCHESTRATOR_RUNNING.load(Ordering::SeqCst)
@@ -214,14 +219,25 @@ impl Job for InboxProcessJob {
                     folder_rel, file_count,
                 ));
 
-                let (ok, fail) =
-                    process_folder_batch(&ctx.db, &config, &ctx.pool, &folder_rel, reviews, log)
-                        .await;
+                // Large folders are split into chunks: a single LLM call for
+                // 100+ files overflows the completion window and the whole
+                // batch fails with a truncated-JSON parse error.
+                for chunk in reviews.chunks(MAX_LLM_BATCH_FILES) {
+                    let (ok, fail) = process_folder_batch(
+                        &ctx.db,
+                        &config,
+                        &ctx.pool,
+                        &folder_rel,
+                        chunk.to_vec(),
+                        log,
+                    )
+                    .await;
 
-                total_ok += ok;
-                total_fail += fail;
+                    total_ok += ok;
+                    total_fail += fail;
+                }
                 log.info(&format!(
-                    "Folder done: {ok} ok, {fail} err. Total so far: {total_ok} ok, {total_fail} err"
+                    "Folder done. Total so far: {total_ok} ok, {total_fail} err"
                 ));
             }
         }
@@ -344,6 +360,7 @@ async fn process_folder_batch(
     log.info("Phase 1: extracting metadata...");
     let mut prepared: Vec<PreparedFile> = Vec::with_capacity(file_count);
     let mut failed_reviews: Vec<PendingReview> = Vec::new();
+    let mut merged_count = 0u64;
 
     for mut review in reviews {
         let stored_input_path = review.input_path_str().to_owned();
@@ -355,9 +372,6 @@ async fn process_folder_batch(
             .unwrap_or("unknown")
             .to_owned();
 
-        // Set status → processing
-        let _ = review.set_processing(db).await;
-
         // Parse context_json
         let mut context: serde_json::Value = review
             .context_json
@@ -365,6 +379,42 @@ async fn process_folder_batch(
             .and_then(|s| serde_json::from_str(s).ok())
             .unwrap_or_default();
 
+        // Resolve duplicates and missing sources before any expensive work.
+        let sha = context
+            .get("sha256")
+            .and_then(|v| v.as_str())
+            .unwrap_or("")
+            .to_owned();
+        let file_exists = file_path.exists();
+        if !sha.is_empty()
+            && crate::agent::rag::file_hash_exists(pool, &sha)
+                .await
+                .unwrap_or(false)
+        {
+            // Identical content is already in the library — drop the inbox
+            // copy (same as mover::Merged) and close the review.
+            if file_exists {
+                let _ = tokio::fs::remove_file(&file_path).await;
+            }
+            let _ = PendingReview::delete_by_ids(db, &[review.id_val()]).await;
+            log.info(&format!(
+                "{filename}: content already in library (sha256 match) — merged duplicate"
+            ));
+            crate::metrics::record_agent_file_processed("ok", "merged_duplicate");
+            merged_count += 1;
+            continue;
+        }
+        if !file_exists {
+            let msg = format!("{filename}: source file missing: {stored_input_path}");
+            log.error(&msg);
+            let _ = review.set_failed(db, &msg).await;
+            failed_reviews.push(review);
+            continue;
+        }
+
+        // Set status → processing
+        let _ = review.set_processing(db).await;
+
         // Extract metadata (with 60s timeout)
         let path_for_meta = file_path.to_path_buf();
         let metadata_start = std::time::Instant::now();
@@ -444,15 +494,16 @@ async fn process_folder_batch(
     }
 
     log.info(&format!(
-        "Phase 1 done: {} prepared, {} failed metadata",
+        "Phase 1 done: {} prepared, {} merged duplicates, {} failed",
         prepared.len(),
+        merged_count,
         failed_reviews.len(),
     ));
 
     if prepared.is_empty() {
         let duration_ms = batch_start.elapsed().as_millis() as i64;
         let _ = run.set_completed(db, duration_ms, &log.output()).await;
-        return (0, failed_reviews.len() as u64);
+        return (merged_count, failed_reviews.len() as u64);
     }
 
     // Phase 2: RAG lookup (collect unique artist/album queries from all files)
@@ -648,16 +699,17 @@ async fn process_folder_batch(
             let err_msg = format!("Batch LLM call failed: {e}");
             log.error(&err_msg);
             // Mark all files as failed
+            let prepared_count = prepared.len() as u64;
             for mut p in prepared {
                 let _ = p.review.set_failed(db, &err_msg).await;
                 crate::metrics::record_agent_file_processed("failed", "failed");
             }
-            let total_fail_count = failed_reviews.len() as u64 + file_count as u64;
+            let total_fail_count = failed_reviews.len() as u64 + prepared_count;
             let duration_ms = batch_start.elapsed().as_millis() as i64;
             let _ = run
                 .set_failed(db, duration_ms, &log.output(), &err_msg)
                 .await;
-            return (0, total_fail_count);
+            return (merged_count, total_fail_count);
         }
     };
 
@@ -681,7 +733,7 @@ async fn process_folder_batch(
     let completion_per_file = batch_result.completion_tokens / prepared.len().max(1) as u64;
     let duration_per_file = batch_result.duration_ms as i64 / prepared.len().max(1) as i64;
 
-    let mut ok_count = 0u64;
+    let mut ok_count = merged_count;
     let mut fail_count = failed_reviews.len() as u64;
 
     for mut p in prepared {

src/lastfm.rs

@@ -447,17 +447,17 @@ async fn fetch_pending_scrobbles(
                   o.duration_seconds,
                   o.attempt_count,
                   a.session_key::text AS session_key,
-                  t.title::text AS title,
-                  r.title::text AS album_title,
+                  COALESCE(o.track_title, t.title::text) AS title,
+                  COALESCE(o.album_title, r.title::text) AS album_title,
                   t.track_number,
-                  (
+                  COALESCE(o.artist_name, (
                     SELECT ar.name::text
                       FROM furumusic__track_artist ta
                       JOIN furumusic__artist ar ON ar.id = ta.artist_id
                      WHERE ta.track_id = t.id AND ta.role <> 'featuring'
                      ORDER BY ta.position
                      LIMIT 1
-                  ) AS artist_name,
+                  )) AS artist_name,
                   (
                     SELECT ar.name::text
                       FROM furumusic__release_artist ra
@@ -468,7 +468,7 @@ async fn fetch_pending_scrobbles(
                   ) AS album_artist_name
              FROM furumusic__lastfm_scrobble_outbox o
              JOIN furumusic__lastfm_account a ON a.user_id = o.user_id
-             JOIN furumusic__track t ON t.id = o.track_id
+             LEFT JOIN furumusic__track t ON t.id = o.track_id
              LEFT JOIN furumusic__release r ON r.id = t.release_id
             WHERE o.user_id = $1
               AND o.status IN ('pending', 'retry')

src/main.rs

@@ -3,6 +3,7 @@ mod agent;
 mod api;
 mod auth;
 mod config;
+mod federation;
 mod i18n;
 mod jobs;
 mod lastfm;
@@ -559,6 +560,13 @@ impl Project for FuruProject {
                 .await;
         });
 
+        // Join the federation at boot when it was left enabled (the settings
+        // live in the config KV table; changes apply live from the admin).
+        let fed_config = Arc::clone(&self.app_config);
+        tokio::spawn(async move {
+            federation::handle().boot(&fed_config).await;
+        });
+
         apps.register(cot::session::db::SessionApp::new());
         apps.register_with_views(
             FuruApp {

src/metrics.rs

@@ -883,6 +883,7 @@ const KNOWN_HTTP_ROUTES: &[&str] = &[
     "/api/player/lastfm/now-playing",
     "/api/player/lastfm/scrobble",
     "/api/player/agent-queue",
+    "/api/player/offline/manifest",
     "/api/player/torrents",
     "/api/player/torrents/session/{id}",
     "/api/player/torrents/preview",

src/music/mod.rs

@@ -1951,6 +1951,531 @@ pub mod db_migrations {
             &[Operation::custom(create_playlist_share_links).build()];
     }
 
+    #[cot::db::migrations::migration_op]
+    async fn create_fed_device_sync(ctx: migrations::MigrationContext<'_>) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__federation_content_id_cache (
+                    media_file_id BIGINT PRIMARY KEY,
+                    sha256_hash TEXT NOT NULL,
+                    content_id TEXT NOT NULL,
+                    updated_at TEXT NOT NULL
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_furumusic_federation_content_id_cache_content_id
+                   ON furumusic__federation_content_id_cache (content_id)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_device_identity (
+                    user_id BIGINT PRIMARY KEY,
+                    device_id TEXT NOT NULL UNIQUE,
+                    group_id TEXT NOT NULL,
+                    device_name TEXT NOT NULL,
+                    local_seq BIGINT NOT NULL DEFAULT 0,
+                    last_hlc_ms BIGINT NOT NULL DEFAULT 0,
+                    local_seeded_at_ms BIGINT NOT NULL DEFAULT 0,
+                    last_sync TEXT,
+                    last_error TEXT
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_device (
+                    user_id BIGINT NOT NULL,
+                    device_id TEXT NOT NULL,
+                    name TEXT NOT NULL DEFAULT '',
+                    client_version TEXT NOT NULL DEFAULT '',
+                    protocol_version INTEGER NOT NULL DEFAULT 1,
+                    endpoint_id TEXT NOT NULL DEFAULT '',
+                    endpoint_ticket TEXT NOT NULL DEFAULT '',
+                    trusted_at_ms BIGINT,
+                    last_seen_ms BIGINT,
+                    revoked_at_ms BIGINT,
+                    revoked_by TEXT,
+                    revoke_cutoff_seq BIGINT,
+                    PRIMARY KEY (user_id, device_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX IF NOT EXISTS idx_fed_device_single_user
+                   ON furumusic__fed_device (device_id)
+                 WHERE trusted_at_ms IS NOT NULL",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_device_invite (
+                    invite_id TEXT PRIMARY KEY,
+                    user_id BIGINT NOT NULL,
+                    secret_hash TEXT NOT NULL,
+                    expires_at_ms BIGINT NOT NULL,
+                    created_at_ms BIGINT NOT NULL,
+                    used_at_ms BIGINT
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_pending_pairing (
+                    request_id TEXT PRIMARY KEY,
+                    user_id BIGINT NOT NULL,
+                    device_id TEXT NOT NULL,
+                    name TEXT NOT NULL,
+                    client_version TEXT NOT NULL,
+                    endpoint_id TEXT NOT NULL,
+                    endpoint_ticket TEXT NOT NULL,
+                    invite_id TEXT NOT NULL,
+                    created_at_ms BIGINT NOT NULL,
+                    answered_at_ms BIGINT,
+                    status TEXT NOT NULL,
+                    requester_group_id TEXT,
+                    requester_group_active_devices BIGINT NOT NULL DEFAULT 1,
+                    requester_group_devices_json TEXT NOT NULL DEFAULT '[]',
+                    use_requester_group BOOLEAN NOT NULL DEFAULT false
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_fed_pending_pairing_user_status
+                   ON furumusic__fed_pending_pairing (user_id, status, created_at_ms DESC)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_sync_ops (
+                    user_id BIGINT NOT NULL,
+                    op_id TEXT NOT NULL,
+                    origin_device_id TEXT NOT NULL,
+                    seq BIGINT NOT NULL,
+                    kind TEXT NOT NULL,
+                    payload_json JSONB NOT NULL,
+                    hlc_ms BIGINT NOT NULL,
+                    received_at_ms BIGINT NOT NULL,
+                    tombstone BOOLEAN NOT NULL DEFAULT false,
+                    PRIMARY KEY (user_id, op_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_fed_sync_ops_origin_seq
+                   ON furumusic__fed_sync_ops (user_id, origin_device_id, seq)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_fed_sync_ops_tombstone
+                   ON furumusic__fed_sync_ops (user_id, tombstone)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_sync_vector (
+                    user_id BIGINT NOT NULL,
+                    device_id TEXT NOT NULL,
+                    max_seq BIGINT NOT NULL,
+                    PRIMARY KEY (user_id, device_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_peer_ack (
+                    user_id BIGINT NOT NULL,
+                    peer_device_id TEXT NOT NULL,
+                    origin_device_id TEXT NOT NULL,
+                    max_seq BIGINT NOT NULL,
+                    updated_at_ms BIGINT NOT NULL,
+                    PRIMARY KEY (user_id, peer_device_id, origin_device_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_state_like (
+                    user_id BIGINT NOT NULL,
+                    content_id TEXT NOT NULL,
+                    liked BOOLEAN NOT NULL,
+                    hlc_ms BIGINT NOT NULL,
+                    op_id TEXT NOT NULL,
+                    local_track_id BIGINT,
+                    fed_json JSONB,
+                    PRIMARY KEY (user_id, content_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_state_playlist (
+                    user_id BIGINT NOT NULL,
+                    playlist_id TEXT NOT NULL,
+                    local_playlist_id BIGINT,
+                    title TEXT NOT NULL,
+                    deleted BOOLEAN NOT NULL DEFAULT false,
+                    hlc_ms BIGINT NOT NULL,
+                    op_id TEXT NOT NULL,
+                    PRIMARY KEY (user_id, playlist_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX IF NOT EXISTS idx_fed_state_playlist_local
+                   ON furumusic__fed_state_playlist (user_id, local_playlist_id)
+                 WHERE local_playlist_id IS NOT NULL",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_state_playlist_item (
+                    user_id BIGINT NOT NULL,
+                    playlist_id TEXT NOT NULL,
+                    content_id TEXT NOT NULL,
+                    present BOOLEAN NOT NULL DEFAULT true,
+                    position BIGINT NOT NULL DEFAULT 0,
+                    hlc_ms BIGINT NOT NULL,
+                    op_id TEXT NOT NULL,
+                    local_track_id BIGINT,
+                    fed_json JSONB,
+                    PRIMARY KEY (user_id, playlist_id, content_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_fed_state_playlist_item_playlist
+                   ON furumusic__fed_state_playlist_item
+                      (user_id, playlist_id, present, position)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__fed_playback_applied (
+                    user_id BIGINT NOT NULL,
+                    op_id TEXT NOT NULL,
+                    applied_at_ms BIGINT NOT NULL,
+                    PRIMARY KEY (user_id, op_id)
+                )",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0038CreateFedDeviceSync;
+
+    impl migrations::Migration for M0038CreateFedDeviceSync {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0038_create_fed_device_sync";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0037_create_playlist_share_links",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_fed_device_sync).build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn ensure_federation_content_id_cache(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__federation_content_id_cache (
+                    media_file_id BIGINT PRIMARY KEY,
+                    sha256_hash TEXT NOT NULL,
+                    content_id TEXT NOT NULL,
+                    updated_at TEXT NOT NULL
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_furumusic_federation_content_id_cache_content_id
+                   ON furumusic__federation_content_id_cache (content_id)",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0039EnsureFederationContentIdCache;
+
+    impl migrations::Migration for M0039EnsureFederationContentIdCache {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0039_ensure_federation_content_id_cache";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0038_create_fed_device_sync",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(ensure_federation_content_id_cache).build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn create_content_addressed_music_refs(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        // A track reference is durable user-facing identity. `local_track_id`
+        // is availability, not identity: it may become non-NULL after a
+        // federated track is materialized without changing likes/playlists.
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__track_ref (
+                    id BIGSERIAL PRIMARY KEY,
+                    content_id TEXT NOT NULL UNIQUE,
+                    local_track_id BIGINT UNIQUE,
+                    title TEXT NOT NULL,
+                    release_title TEXT,
+                    year INTEGER,
+                    duration_seconds DOUBLE PRECISION,
+                    metadata_json JSONB NOT NULL DEFAULT '{}'::jsonb,
+                    metadata_authority TEXT NOT NULL DEFAULT 'local',
+                    created_at TEXT NOT NULL,
+                    updated_at TEXT NOT NULL
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_track_ref_local_track
+                   ON furumusic__track_ref (local_track_id)
+                 WHERE local_track_id IS NOT NULL",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__federation_track_source (
+                    track_ref_id BIGINT NOT NULL REFERENCES furumusic__track_ref(id)
+                        ON DELETE CASCADE,
+                    owner_peer_id TEXT NOT NULL,
+                    item_id TEXT NOT NULL,
+                    last_seen_ms BIGINT NOT NULL,
+                    metadata_json JSONB NOT NULL DEFAULT '{}'::jsonb,
+                    PRIMARY KEY (owner_peer_id, item_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_federation_track_source_ref
+                   ON furumusic__federation_track_source (track_ref_id, last_seen_ms DESC)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "ALTER TABLE furumusic__user_liked_track
+                   ADD COLUMN IF NOT EXISTS track_ref_id BIGINT
+                       REFERENCES furumusic__track_ref(id)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX IF NOT EXISTS idx_user_liked_track_ref_uniq
+                   ON furumusic__user_liked_track (user_id, track_ref_id)
+                 WHERE track_ref_id IS NOT NULL",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "ALTER TABLE furumusic__playlist_track
+                   ADD COLUMN IF NOT EXISTS track_ref_id BIGINT
+                       REFERENCES furumusic__track_ref(id)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_playlist_track_ref
+                   ON furumusic__playlist_track (track_ref_id)
+                 WHERE track_ref_id IS NOT NULL",
+            )
+            .await?;
+        // History deliberately remains local-track based. Only the web
+        // player's existing playback report records history and triggers
+        // Last.fm scrobbling.
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0040CreateContentAddressedMusicRefs;
+
+    impl migrations::Migration for M0040CreateContentAddressedMusicRefs {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0040_create_content_addressed_music_refs";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0039_ensure_federation_content_id_cache",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_content_addressed_music_refs).build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn create_synced_listen_history(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE TABLE IF NOT EXISTS furumusic__listen_event (
+                    user_id BIGINT NOT NULL,
+                    listen_id TEXT NOT NULL,
+                    content_id TEXT NOT NULL,
+                    local_track_id BIGINT,
+                    origin_device_id TEXT NOT NULL,
+                    started_at_ms BIGINT NOT NULL,
+                    listened_ms BIGINT NOT NULL,
+                    track_duration_ms BIGINT,
+                    ended_reason TEXT NOT NULL,
+                    qualified BOOLEAN NOT NULL,
+                    metadata_json JSONB NOT NULL,
+                    created_at TEXT NOT NULL,
+                    PRIMARY KEY (user_id, listen_id)
+                )",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_listen_event_user_time
+                   ON furumusic__listen_event (user_id, started_at_ms DESC, listen_id)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX IF NOT EXISTS idx_listen_event_content
+                   ON furumusic__listen_event (user_id, content_id)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "INSERT INTO furumusic__listen_event
+                    (user_id, listen_id, content_id, local_track_id,
+                     origin_device_id, started_at_ms, listened_ms,
+                     track_duration_ms, ended_reason, qualified,
+                     metadata_json, created_at)
+                 SELECT ph.user_id,
+                        'legacy-web:' || ph.id::text,
+                        tr.content_id,
+                        ph.track_id,
+                        ident.device_id,
+                        (EXTRACT(EPOCH FROM ph.played_at::timestamptz) * 1000)::bigint,
+                        COALESCE(ph.duration_listened, 0)::bigint * 1000,
+                        (t.duration_seconds * 1000)::bigint,
+                        CASE WHEN ph.completed THEN '\"finished\"' ELSE '\"unknown\"' END,
+                        ph.completed,
+                        jsonb_build_object(
+                            'title', t.title::text,
+                            'artist_names', COALESCE((
+                                SELECT jsonb_agg(a.name::text ORDER BY ta.position)
+                                  FROM furumusic__track_artist ta
+                                  JOIN furumusic__artist a ON a.id = ta.artist_id
+                                 WHERE ta.track_id = t.id
+                                   AND ta.role <> 'featuring'
+                            ), '[]'::jsonb),
+                            'featured_artist_names', COALESCE((
+                                SELECT jsonb_agg(a.name::text ORDER BY ta.position)
+                                  FROM furumusic__track_artist ta
+                                  JOIN furumusic__artist a ON a.id = ta.artist_id
+                                 WHERE ta.track_id = t.id
+                                   AND ta.role = 'featuring'
+                            ), '[]'::jsonb),
+                            'release_title', r.title::text
+                        ),
+                        ph.played_at::text
+                   FROM furumusic__play_history ph
+                   JOIN furumusic__track t ON t.id = ph.track_id
+                   JOIN furumusic__track_ref tr ON tr.local_track_id = ph.track_id
+                   JOIN furumusic__fed_device_identity ident
+                     ON ident.user_id = ph.user_id
+                   LEFT JOIN furumusic__release r ON r.id = t.release_id
+                 ON CONFLICT (user_id, listen_id) DO NOTHING",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "ALTER TABLE furumusic__lastfm_scrobble_outbox
+                   ALTER COLUMN track_id DROP NOT NULL",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "ALTER TABLE furumusic__lastfm_scrobble_outbox
+                   ADD COLUMN IF NOT EXISTS track_title TEXT,
+                   ADD COLUMN IF NOT EXISTS artist_name TEXT,
+                   ADD COLUMN IF NOT EXISTS album_title TEXT",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0041CreateSyncedListenHistory;
+
+    impl migrations::Migration for M0041CreateSyncedListenHistory {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0041_create_synced_listen_history";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0040_create_content_addressed_music_refs",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_synced_listen_history).build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn repair_legacy_listen_qualification(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "UPDATE furumusic__listen_event le
+                    SET qualified = (
+                        ph.completed
+                        OR (
+                            COALESCE(ph.duration_listened, 0) >= 5
+                            AND COALESCE(t.duration_seconds, 0) > 0
+                            AND COALESCE(ph.duration_listened, 0) >= LEAST(
+                                COALESCE(t.duration_seconds, 0) / 2.0,
+                                240.0
+                            )
+                        )
+                    )
+                   FROM furumusic__play_history ph
+                   JOIN furumusic__track t ON t.id = ph.track_id
+                  WHERE le.user_id = ph.user_id
+                    AND le.listen_id = 'legacy-web:' || ph.id::text",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0042RepairLegacyListenQualification;
+
+    impl migrations::Migration for M0042RepairLegacyListenQualification {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0042_repair_legacy_listen_qualification";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0041_create_synced_listen_history",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(repair_legacy_listen_qualification).build()];
+    }
+
     pub const MIGRATIONS: &[&SyncDynMigration] = &[
         &M0006CreateMediaFile,
         &M0007CreateArtist,
@@ -1979,5 +2504,10 @@ pub mod db_migrations {
         &M0035CreateEntityGenreTags,
         &M0036CreateExternalMetadataIds,
         &M0037CreatePlaylistShareLinks,
+        &M0038CreateFedDeviceSync,
+        &M0039EnsureFederationContentIdCache,
+        &M0040CreateContentAddressedMusicRefs,
+        &M0041CreateSyncedListenHistory,
+        &M0042RepairLegacyListenQualification,
     ];
 }

src/oidc.rs

@@ -977,27 +977,54 @@ fn safe_mobile_redirect_uri(raw: Option<&str>) -> Option<String> {
     if lower.starts_with("furumi://") || lower.starts_with("furumusic://") {
         return Some(value.to_owned());
     }
+    if is_loopback_http_redirect(&lower) {
+        return Some(value.to_owned());
+    }
     None
 }
 
+/// RFC 8252 §7.3: native apps without a custom URL scheme (the CLI client)
+/// receive the callback on a loopback listener with an ephemeral port.
+fn is_loopback_http_redirect(lower: &str) -> bool {
+    let Some(rest) = lower.strip_prefix("http://") else {
+        return false;
+    };
+    let host_port = rest.split(['/', '?', '#']).next().unwrap_or("");
+    let Some((host, port)) = host_port.rsplit_once(':') else {
+        return false;
+    };
+    matches!(host, "127.0.0.1" | "localhost" | "[::1]")
+        && !port.is_empty()
+        && port.len() <= 5
+        && port.bytes().all(|b| b.is_ascii_digit())
+}
+
 fn mobile_redirect_success(app_redirect_uri: &str, code: &str) -> cot::response::Response {
     let deep_link = append_query_param(app_redirect_uri, "code", code);
+    if is_loopback_http_redirect(&app_redirect_uri.to_ascii_lowercase()) {
+        return auth::redirect(&deep_link);
+    }
     mobile_deep_link_page(
         "success",
         "Sign-in complete",
-        "Furumi should open automatically. You can close this window after the app opens.",
+        "Furumi should open automatically. If it doesn't, use the button or copy the code below.",
         None,
+        Some(code),
         &deep_link,
     )
 }
 
 fn mobile_redirect_error(app_redirect_uri: &str, error: &str) -> cot::response::Response {
     let deep_link = append_query_param(app_redirect_uri, "error", error);
+    if is_loopback_http_redirect(&app_redirect_uri.to_ascii_lowercase()) {
+        return auth::redirect(&deep_link);
+    }
     mobile_deep_link_page(
         "error",
         "Sign-in failed",
-        "Furumi should open automatically and show the sign-in error. You can close this window after the app opens.",
+        "Furumi should open automatically and show the sign-in error.",
         Some(error),
+        None,
         &deep_link,
     )
 }
@@ -1007,6 +1034,7 @@ fn mobile_deep_link_page(
     title: &str,
     message: &str,
     detail: Option<&str>,
+    code: Option<&str>,
     deep_link: &str,
 ) -> cot::response::Response {
     let state_class = html_escape(state);
@@ -1015,6 +1043,15 @@ fn mobile_deep_link_page(
     let detail_html = detail
         .map(|value| format!(r#"<p class="detail">Reason: {}</p>"#, html_escape(value)))
         .unwrap_or_default();
+    let code_html = code
+        .map(|value| {
+            format!(
+                r#"<p class="hint">Signing in from a terminal? Paste this code there:</p>
+    <input class="code" readonly value="{}" onclick="this.select()">"#,
+                html_escape(value)
+            )
+        })
+        .unwrap_or_default();
     let deep_link_html = html_escape(deep_link);
     let deep_link_js =
         serde_json::to_string(deep_link).expect("serializing URL string cannot fail");
@@ -1095,6 +1132,19 @@ fn mobile_deep_link_page(
       font-size: 13px;
       color: #89847c;
     }}
+    .code {{
+      width: 100%;
+      margin-top: 8px;
+      padding: 10px 12px;
+      box-sizing: border-box;
+      border: 1px solid #3a3c42;
+      border-radius: 8px;
+      background: #1a1c20;
+      color: #e8d8a8;
+      font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
+      font-size: 13px;
+      text-align: center;
+    }}
   </style>
 </head>
 <body>
@@ -1105,15 +1155,13 @@ fn mobile_deep_link_page(
     {detail_html}
     <a href="{deep_link_html}">Open Furumi</a>
     <p class="hint">If nothing happens, use the button above.</p>
+    {code_html}
   </main>
   <script>
     const deepLink = {deep_link_js};
     window.setTimeout(() => {{
       window.location.href = deepLink;
     }}, 100);
-    window.setTimeout(() => {{
-      window.close();
-    }}, 1800);
   </script>
 </body>
 </html>"#,
@@ -1230,4 +1278,25 @@ mod tests {
         );
         assert!(safe_mobile_redirect_uri(Some("https://example.com/callback")).is_none());
     }
+
+    #[test]
+    fn mobile_oidc_redirect_uri_allows_loopback_http() {
+        assert_eq!(
+            safe_mobile_redirect_uri(Some("http://127.0.0.1:8753/callback")).as_deref(),
+            Some("http://127.0.0.1:8753/callback")
+        );
+        assert_eq!(
+            safe_mobile_redirect_uri(Some("http://localhost:1234/callback")).as_deref(),
+            Some("http://localhost:1234/callback")
+        );
+        assert_eq!(
+            safe_mobile_redirect_uri(Some("http://[::1]:1234/callback")).as_deref(),
+            Some("http://[::1]:1234/callback")
+        );
+        // Non-loopback hosts, missing ports and https stay rejected.
+        assert!(safe_mobile_redirect_uri(Some("http://127.0.0.1/callback")).is_none());
+        assert!(safe_mobile_redirect_uri(Some("http://evil.com:80/callback")).is_none());
+        assert!(safe_mobile_redirect_uri(Some("https://127.0.0.1:80/callback")).is_none());
+        assert!(safe_mobile_redirect_uri(Some("http://127.0.0.1:notaport/x")).is_none());
+    }
 }

src/player/dto.rs

@@ -51,6 +51,7 @@ pub(super) struct ArtistRef {
 #[derive(Debug, Clone, Serialize, JsonSchema)]
 pub(super) struct TrackItem {
     pub(super) id: i64,
+    pub(super) content_id: Option<String>,
     pub(super) title: String,
     pub(super) track_number: Option<i32>,
     pub(super) disc_number: Option<i32>,
@@ -74,6 +75,15 @@ pub(super) struct TrackItem {
     pub(super) lastfm_updated_at: Option<String>,
 }
 
+#[derive(Debug, Serialize, JsonSchema)]
+pub(super) struct PlaylistTrackItem {
+    pub(super) playlist_track_id: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(super) sort_key: Option<i64>,
+    #[serde(flatten)]
+    pub(super) track: TrackItem,
+}
+
 #[derive(Debug, Serialize, JsonSchema)]
 pub(super) struct ArtistAppearanceTrack {
     pub(super) id: i64,
@@ -265,6 +275,24 @@ pub(super) struct PlayerDevicesResponse {
     pub(super) playback_state: Option<PlayerDevicePlaybackStateDto>,
 }
 
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FedDeviceConnectRequest {
+    pub(super) invite: String,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FedDevicePairingAnswerRequest {
+    pub(super) request_id: String,
+    pub(super) accept: bool,
+    #[serde(default)]
+    pub(super) use_requester_group: bool,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FedDeviceRevokeRequest {
+    pub(super) device_id: String,
+}
+
 #[derive(Debug, Serialize, JsonSchema)]
 pub(super) struct PlayerDevicePollResponse {
     pub(super) device_id: String,
@@ -286,7 +314,7 @@ pub(super) struct PlaylistDetail {
     pub(super) is_public: bool,
     pub(super) is_saved: bool,
     pub(super) kind: String,
-    pub(super) tracks: Vec<TrackItem>,
+    pub(super) tracks: Vec<PlaylistTrackItem>,
 }
 
 #[derive(Debug, Serialize, JsonSchema)]
@@ -325,6 +353,45 @@ pub(super) struct UserProfile {
     pub(super) stats: UserStats,
 }
 
+#[derive(Debug, Serialize, JsonSchema)]
+pub(super) struct OfflineManifestResponse {
+    pub(super) generated_at: String,
+    pub(super) tracks: Vec<OfflineTrackManifestItem>,
+    pub(super) playlists: Vec<OfflinePlaylistManifestItem>,
+    pub(super) liked_track_ids: Vec<i64>,
+    pub(super) followed_artist_ids: Vec<i64>,
+}
+
+#[derive(Debug, Serialize, JsonSchema)]
+pub(super) struct OfflineTrackManifestItem {
+    pub(super) id: i64,
+    pub(super) updated_at: String,
+    pub(super) stream_url: String,
+    pub(super) audio_file_id: i64,
+    pub(super) audio_hash: String,
+    pub(super) audio_size_bytes: i64,
+    pub(super) audio_mime_type: String,
+    pub(super) audio_updated_at: String,
+    pub(super) cover_file_id: Option<i64>,
+    pub(super) cover_url: Option<String>,
+    pub(super) cover_hash: Option<String>,
+    pub(super) cover_updated_at: Option<String>,
+}
+
+#[derive(Debug, Serialize, JsonSchema)]
+pub(super) struct OfflinePlaylistManifestItem {
+    pub(super) id: i64,
+    pub(super) title: String,
+    pub(super) description: Option<String>,
+    pub(super) updated_at: String,
+    pub(super) is_own: bool,
+    pub(super) owner_name: Option<String>,
+    pub(super) is_public: bool,
+    pub(super) is_saved: bool,
+    pub(super) kind: String,
+    pub(super) track_ids: Vec<i64>,
+}
+
 #[derive(Debug, Serialize, JsonSchema)]
 pub(super) struct LastfmStatus {
     pub(super) configured: bool,
@@ -474,14 +541,16 @@ pub(super) struct UserUploadReviewUpdateRequest {
 
 #[derive(Debug, Serialize, JsonSchema)]
 pub(super) struct PlayHistoryItem {
-    pub(super) id: i64,
-    pub(super) track_id: i64,
+    pub(super) id: String,
+    pub(super) track_id: Option<i64>,
     pub(super) track_title: String,
     pub(super) release_title: Option<String>,
-    pub(super) track: TrackItem,
+    pub(super) track: serde_json::Value,
     pub(super) played_at: String,
     pub(super) duration_listened: Option<i32>,
     pub(super) completed: bool,
+    pub(super) device_id: String,
+    pub(super) device_name: String,
 }
 
 #[derive(Debug, Serialize, JsonSchema)]
@@ -497,6 +566,46 @@ pub(super) struct LikeStatus {
     pub(super) liked: bool,
 }
 
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct ContentTrackMutation {
+    pub(super) content_id: String,
+    pub(super) liked: Option<bool>,
+    pub(super) playlist_id: Option<i64>,
+    pub(super) position: Option<i64>,
+    pub(super) federation: Option<serde_json::Value>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct PrepareFederatedTrackRequest {
+    pub(super) content_id: String,
+    pub(super) owner: Option<String>,
+    pub(super) item_id: Option<String>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FederationArtworkQuery {
+    pub(super) owner: String,
+    pub(super) item_id: String,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FederationArtistQuery {
+    pub(super) name: String,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FederationCatalogArtworkQuery {
+    pub(super) owner: String,
+    pub(super) artist: String,
+    pub(super) release: Option<String>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub(super) struct FederationArtworkDiscoveryQuery {
+    pub(super) artist: String,
+    pub(super) release: Option<String>,
+}
+
 #[derive(Debug, Serialize, JsonSchema)]
 pub(super) struct LikedIds {
     pub(super) track_ids: Vec<i64>,

src/player/queries.rs

@@ -3,9 +3,11 @@ use serde::Deserialize;
 #[derive(Debug, Deserialize)]
 pub(super) struct HistoryEntry {
     pub(super) track_id: i64,
+    pub(super) listen_id: Option<String>,
     pub(super) started_at: Option<i64>,
     pub(super) duration_listened: Option<i32>,
     pub(super) completed: bool,
+    pub(super) ended_reason: Option<String>,
 }
 
 #[derive(Debug, Deserialize)]
@@ -42,7 +44,13 @@ pub(super) struct AddTracksRequest {
 
 #[derive(Debug, Deserialize)]
 pub(super) struct RemoveTrackRequest {
-    pub(super) track_id: i64,
+    pub(super) track_id: Option<i64>,
+    pub(super) playlist_track_id: Option<i64>,
+}
+
+#[derive(Debug, Deserialize)]
+pub(super) struct ReorderPlaylistRequest {
+    pub(super) playlist_track_ids: Vec<i64>,
 }
 
 #[derive(Debug, Deserialize)]

src/player/rows.rs

@@ -56,6 +56,8 @@ pub(super) struct MediaFileRow {
     pub(super) file_path: String,
     pub(super) mime_type: String,
     pub(super) file_size_bytes: i64,
+    pub(super) sha256_hash: String,
+    pub(super) created_at: String,
 }
 
 #[derive(sqlx::FromRow)]
@@ -93,6 +95,7 @@ pub(super) struct PlaylistInfoRow {
 
 #[derive(sqlx::FromRow)]
 pub(super) struct PlaylistTrackRow {
+    pub(super) playlist_track_id: Option<i64>,
     pub(super) id: i64,
     pub(super) title: String,
     pub(super) track_number: Option<i32>,
@@ -251,34 +254,6 @@ pub(super) struct ReleaseUploaderRow {
     pub(super) track_count: i64,
 }
 
-#[derive(sqlx::FromRow)]
-pub(super) struct PlayHistoryTrackRow {
-    pub(super) history_id: i64,
-    pub(super) played_at: String,
-    pub(super) duration_listened: Option<i32>,
-    pub(super) completed: bool,
-    pub(super) id: i64,
-    pub(super) title: String,
-    pub(super) track_number: Option<i32>,
-    pub(super) disc_number: Option<i32>,
-    pub(super) duration_seconds: f64,
-    pub(super) cover_file_id: Option<i64>,
-    pub(super) release_cover_file_id: Option<i64>,
-    pub(super) release_id: i64,
-    pub(super) release_title: String,
-    pub(super) release_year: Option<i32>,
-    pub(super) uploader_name: String,
-    pub(super) audio_format: Option<String>,
-    pub(super) audio_bitrate: Option<i32>,
-    pub(super) audio_sample_rate: Option<i32>,
-    pub(super) audio_bit_depth: Option<i32>,
-    pub(super) file_size_bytes: Option<i64>,
-    pub(super) lastfm_listeners: Option<i64>,
-    pub(super) lastfm_playcount: Option<i64>,
-    pub(super) lastfm_rating: Option<f64>,
-    pub(super) lastfm_updated_at: Option<String>,
-}
-
 #[derive(sqlx::FromRow)]
 pub(super) struct ReleaseInfoRow {
     pub(super) id: i64,
@@ -287,3 +262,30 @@ pub(super) struct ReleaseInfoRow {
     pub(super) year: Option<i32>,
     pub(super) cover_file_id: Option<i64>,
 }
+
+#[derive(sqlx::FromRow)]
+pub(super) struct OfflineTrackManifestRow {
+    pub(super) id: i64,
+    pub(super) updated_at: String,
+    pub(super) audio_file_id: i64,
+    pub(super) audio_hash: String,
+    pub(super) audio_size_bytes: i64,
+    pub(super) audio_mime_type: String,
+    pub(super) audio_updated_at: String,
+    pub(super) cover_file_id: Option<i64>,
+    pub(super) cover_hash: Option<String>,
+    pub(super) cover_updated_at: Option<String>,
+}
+
+#[derive(sqlx::FromRow)]
+pub(super) struct OfflinePlaylistManifestRow {
+    pub(super) id: i64,
+    pub(super) title: String,
+    pub(super) description: Option<String>,
+    pub(super) updated_at: String,
+    pub(super) is_own: bool,
+    pub(super) owner_name: String,
+    pub(super) is_public: bool,
+    pub(super) is_saved: bool,
+    pub(super) track_ids: Vec<i64>,
+}

src/scheduler/mod.rs

@@ -496,14 +496,24 @@ impl PendingReview {
             .await
     }
 
-    pub async fn exists_for_path(db: &Database, path: &str) -> cot::db::Result<bool> {
-        let all = Self::objects().all(db).await?;
-        let exists = all.iter().any(|r| {
-            let s = r.status.as_str();
-            // "rejected" and "failed" reviews should not block re-discovery
-            s != "rejected" && s != "failed" && r.input_path.as_deref() == Some(path)
-        });
-        Ok(exists)
+    /// Latest review row for an inbox path: `(id, status, updated_at)`.
+    ///
+    /// Used by inbox_discover to decide whether a file needs a new review,
+    /// a requeue of its existing row, or nothing at all — without creating
+    /// a fresh row per retry.
+    pub async fn latest_for_path(
+        pool: &sqlx::PgPool,
+        path: &str,
+    ) -> anyhow::Result<Option<(i64, String, String)>> {
+        let row: Option<(i64, String, String)> = sqlx::query_as(
+            "SELECT id, status::text, updated_at::text \
+             FROM furumusic__pending_review WHERE input_path = $1 \
+             ORDER BY id DESC LIMIT 1",
+        )
+        .bind(path)
+        .fetch_optional(pool)
+        .await?;
+        Ok(row)
     }
 
     /// Mark all "processing" reviews as "failed" — called at scheduler

templates/admin/v2.html

@@ -1193,6 +1193,77 @@ tbody tr:hover {
     gap: 12px;
 }
 
+.release-track-search-row {
+    display: grid;
+    grid-template-columns: minmax(0, 1fr) auto;
+    gap: 8px;
+    margin-bottom: 10px;
+}
+
+.release-track-list {
+    border: 1px solid var(--border-color);
+    border-radius: 8px;
+    background: var(--bg-primary);
+    overflow: hidden;
+}
+
+.release-track-head,
+.release-track-row {
+    display: grid;
+    grid-template-columns: 72px 82px minmax(0, 1.4fr) minmax(0, 1fr) minmax(0, .9fr) 70px 36px;
+    gap: 8px;
+    align-items: center;
+    padding: 8px;
+}
+
+.release-track-head {
+    min-height: 34px;
+    border-bottom: 1px solid var(--border-color);
+    color: var(--text-subdued);
+    font-size: 10px;
+    font-weight: 850;
+    text-transform: uppercase;
+}
+
+.release-track-row {
+    min-height: 48px;
+    border-bottom: 1px solid rgba(255, 255, 255, 0.055);
+}
+
+.release-track-row:last-child {
+    border-bottom: 0;
+}
+
+.release-track-row:hover {
+    background: rgba(255, 255, 255, 0.03);
+}
+
+.release-track-row input {
+    width: 100%;
+    height: 30px;
+    min-height: 30px;
+    padding: 0 8px;
+}
+
+.release-track-title,
+.release-track-meta {
+    min-width: 0;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+
+.release-track-title {
+    color: var(--text-primary);
+    font-size: 12px;
+    font-weight: 750;
+}
+
+.release-track-meta {
+    color: var(--text-subdued);
+    font-size: 11px;
+}
+
 .image-actions {
     display: flex;
     align-items: center;
@@ -1542,7 +1613,7 @@ tbody tr:hover {
                             </button>
                             <button class="btn" @click="selectReviewFilter()" :disabled="reviews.total === 0">
                                 <i data-lucide="list-checks"></i>
-                                Select filter
+                                <span x-text="`Select all (${fmt(reviews.total)})`"></span>
                             </button>
                             <button class="btn" @click="clearReviewSelection()" :disabled="selectedReviewCount() === 0">
                                 <i data-lucide="x"></i>
@@ -1836,6 +1907,10 @@ tbody tr:hover {
                                 <i data-lucide="square-pen"></i>
                                 Edit
                             </button>
+                            <button class="btn primary" x-show="libraryKind === 'releases'" @click="openReleaseCreator()">
+                                <i data-lucide="plus"></i>
+                                New release
+                            </button>
                             <button class="btn warn" @click="mockAction('Merge wizard will open from this action slot')">
                                 <i data-lucide="git-merge"></i>
                                 Merge
@@ -2190,6 +2265,107 @@ tbody tr:hover {
                             </div>
                         </section>
 
+                        <section class="panel">
+                            <div class="panel-head">
+                                <div class="panel-title">
+                                    <strong>Federation</strong>
+                                    <span>Publish this library into the furumi P2P network</span>
+                                </div>
+                                <span class="badge" :class="federationStatus.node && federationStatus.node.running ? 'ok' : 'disabled'" x-text="federationStatus.node && federationStatus.node.running ? 'running' : 'stopped'"></span>
+                            </div>
+                            <div class="settings-grid">
+                                <div class="setting-toggle">
+                                    <label>
+                                        <span>Federation enabled</span>
+                                        <span class="source-pill" :class="sourceClass('federation_enabled')" x-text="settingSource('federation_enabled')"></span>
+                                    </label>
+                                    <div class="setting-toggle-row">
+                                        <span x-text="settingsDraft.federation_enabled ? 'Enabled' : 'Disabled'"></span>
+                                        <input type="checkbox" x-model="settingsDraft.federation_enabled" />
+                                    </div>
+                                    <div class="setting-help">Applies immediately on save — no restart needed. Peers can browse and stream every visible track.</div>
+                                </div>
+                                <div class="setting-field settings-wide">
+                                    <label>
+                                        <span>Network ID (shared secret)</span>
+                                        <span class="source-pill" :class="sourceClass('federation_network_id')" x-text="settingSource('federation_network_id')"></span>
+                                    </label>
+                                    <input x-model="settingsDraft.federation_network_id" placeholder="my-crew-music-7f3a" autocomplete="off" />
+                                    <div class="setting-help">Every peer using the same id finds the others automatically.</div>
+                                </div>
+                                <div class="setting-field">
+                                    <label>
+                                        <span>Save federated tracks on play</span>
+                                        <span class="source-pill" :class="sourceClass('federation_save_on_listen')" x-text="settingSource('federation_save_on_listen')"></span>
+                                    </label>
+                                    <div class="setting-toggle-row">
+                                        <span x-text="settingsDraft.federation_save_on_listen ? 'Import into the shared library' : 'Use temporary cache'"></span>
+                                        <input type="checkbox" x-model="settingsDraft.federation_save_on_listen" />
+                                    </div>
+                                    <div class="setting-help">Server-wide policy. Imported tracks become available to every user and are published by this peer. Federation metadata is trusted and bypasses the AI agent.</div>
+                                </div>
+                            </div>
+                            <div class="probe-body" x-show="federationStatus.node">
+                                <div class="probe-table" x-show="federationStatus.node && federationStatus.node.running">
+                                    <div class="probe-row"><span>Endpoint</span><strong x-text="fedShort(federationStatus.node && federationStatus.node.endpoint_id)"></strong></div>
+                                    <div class="probe-row"><span>Network</span><strong x-text="(federationStatus.node && federationStatus.node.network) || '-'"></strong></div>
+                                    <div class="probe-row"><span>Connected peers</span><strong x-text="federationStatus.node && federationStatus.node.connected_peers ? federationStatus.node.connected_peers.length : 0"></strong></div>
+                                    <div class="probe-row"><span>Known contacts</span><strong x-text="(federationStatus.node && federationStatus.node.known_contacts) ?? '-'"></strong></div>
+                                    <div class="probe-row"><span>Published items</span><strong x-text="(federationStatus.node && federationStatus.node.published_items) ?? '-'"></strong></div>
+                                    <div class="probe-row"><span>Last sync</span><strong x-text="federationStatus.last_sync || 'not yet'"></strong></div>
+                                </div>
+                                <div class="probe-table" x-show="fedTransport().total_samples > 0" style="margin-top:10px">
+                                    <div class="probe-row">
+                                        <span>Transport path</span>
+                                        <strong>
+                                            <span class="badge" :class="fedPathBadge(fedTransport().last_path)" x-text="fedTransport().last_path || 'unknown'"></span>
+                                        </strong>
+                                    </div>
+                                    <div class="probe-row"><span>RTT</span><strong x-text="fedRtt(fedTransport().last_rtt_ms)"></strong></div>
+                                    <div class="probe-row"><span>Path samples</span><strong x-text="`${fedTransport().direct_samples || 0} direct · ${fedTransport().relay_samples || 0} relay · ${fedTransport().custom_samples || 0} custom · ${fedTransport().unknown_samples || 0} unknown`"></strong></div>
+                                    <div class="probe-row"><span>Protocols</span><strong x-text="`${fedTransport().audio_samples || 0} audio · ${fedTransport().catalog_samples || 0} catalog · ${fedTransport().sync_samples || 0} sync`"></strong></div>
+                                    <div class="probe-row"><span>Last peer</span><strong x-text="fedShort(fedTransport().last_peer)"></strong></div>
+                                </div>
+                                <div class="probe-table" x-show="fedTransport().last && fedTransport().last.length" style="margin-top:10px">
+                                    <template x-for="(sample, index) in fedTransport().last.slice(0, 5)" :key="`${sample.at}-${sample.protocol}-${sample.direction}-${sample.phase}-${sample.peer_id}-${index}`">
+                                        <div class="probe-row">
+                                            <span x-text="`${sample.protocol} · ${sample.direction} · ${sample.phase}`"></span>
+                                            <strong>
+                                                <span class="badge" :class="fedPathBadge(sample.selected_path)" x-text="sample.selected_path || 'unknown'"></span>
+                                                <span x-text="` ${fedRtt(sample.selected_rtt_ms)} · tx ${formatBytes(sample.total_tx_bytes || 0)} · rx ${formatBytes(sample.total_rx_bytes || 0)} · lost ${formatBytes(sample.lost_bytes || 0)}`"></span>
+                                            </strong>
+                                        </div>
+                                    </template>
+                                </div>
+                                <p class="probe-intro muted" x-show="federationStatus.last_error" x-text="federationStatus.last_error"></p>
+                                <div class="toolbar" style="margin-top:14px; flex-wrap:wrap; gap:8px">
+                                    <button class="btn" type="button" @click="loadFederation()" :disabled="federationLoading">
+                                        <i data-lucide="refresh-cw"></i>
+                                        Refresh
+                                    </button>
+                                    <button class="btn" type="button" @click="fedSyncNow()" :disabled="federationLoading || !(federationStatus.node && federationStatus.node.running)">
+                                        <i data-lucide="upload-cloud"></i>
+                                        Publish now
+                                    </button>
+                                    <button class="btn" type="button" @click="fedShowTicket()" :disabled="federationLoading || !(federationStatus.node && federationStatus.node.running)">
+                                        <i data-lucide="ticket"></i>
+                                        Show ticket
+                                    </button>
+                                </div>
+                                <div class="setting-field settings-wide" x-show="federationTicket" style="margin-top:10px">
+                                    <label>Connection ticket (share with a peer)</label>
+                                    <textarea readonly rows="3" style="width:100%; font-family:monospace; font-size:11px" x-text="federationTicket"></textarea>
+                                </div>
+                                <div class="setting-field settings-wide" x-show="federationStatus.node && federationStatus.node.running" style="margin-top:10px">
+                                    <label>Connect to a peer by ticket</label>
+                                    <div style="display:flex; gap:8px">
+                                        <input x-model="fedConnectTicket" placeholder="fnet..." style="flex:1" autocomplete="off" />
+                                        <button class="btn" type="button" @click="fedConnect()" :disabled="federationLoading || !fedConnectTicket.trim()">Connect</button>
+                                    </div>
+                                </div>
+                            </div>
+                        </section>
+
                         <section class="panel">
                             <div class="panel-head">
                                 <div class="panel-title">
@@ -2419,8 +2595,8 @@ tbody tr:hover {
         <section class="modal">
             <div class="modal-head">
                 <div class="panel-title">
-                    <strong x-text="activeLibraryItem?.title || 'Editor'"></strong>
-                    <span x-text="activeLibraryItem?.kind || 'Library entity'"></span>
+                    <strong x-text="editorTitle()"></strong>
+                    <span x-text="editorSubtitle()"></span>
                 </div>
                 <button class="icon-btn" @click="editorOpen = false">
                     <i data-lucide="x"></i>
@@ -2454,6 +2630,54 @@ tbody tr:hover {
                         </div>
                     </div>
 
+                    <div class="field" x-show="isReleaseEditor()">
+                        <label>Release tracks</label>
+                        <div class="release-track-search-row">
+                            <div class="artist-picker">
+                                <input class="search" placeholder="Search track" x-model="releaseTrackSearch" @input.debounce.300ms="searchReleaseTracks()" @keydown.enter.prevent="addBestReleaseTrack()" @keydown.escape="clearReleaseTrackSearch()" />
+                                <div class="artist-results" x-show="releaseTrackSearchOpen()" x-transition>
+                                    <template x-for="track in availableReleaseTrackResults()" :key="track.id">
+                                        <button class="artist-result" type="button" @click="addReleaseTrack(track)">
+                                            <span x-text="track.title"></span>
+                                            <small x-text="releaseTrackSearchMeta(track)"></small>
+                                        </button>
+                                    </template>
+                                    <div class="artist-result muted" x-show="releaseTrackSearchLoading">Searching...</div>
+                                    <div class="artist-result muted" x-show="!releaseTrackSearchLoading && availableReleaseTrackResults().length === 0">No matching tracks</div>
+                                </div>
+                            </div>
+                            <button class="btn" type="button" @click="addBestReleaseTrack()" :disabled="!releaseTrackSearch.trim()">
+                                <i data-lucide="plus"></i>
+                                Add
+                            </button>
+                        </div>
+                        <div class="release-track-list" x-show="releaseTracks().length">
+                            <div class="release-track-head">
+                                <span>Disc</span>
+                                <span>Track #</span>
+                                <span>Title</span>
+                                <span>Artists</span>
+                                <span>Current release</span>
+                                <span>Time</span>
+                                <span></span>
+                            </div>
+                            <template x-for="track in releaseTracks()" :key="track.id">
+                                <div class="release-track-row">
+                                    <input type="number" min="1" max="999" x-model="track.disc_number" />
+                                    <input type="number" min="1" max="9999" x-model="track.track_number" />
+                                    <div class="release-track-title" x-text="track.title"></div>
+                                    <div class="release-track-meta" x-text="track.artists || 'Unknown artist'"></div>
+                                    <div class="release-track-meta" x-text="releaseTrackOrigin(track)"></div>
+                                    <div class="release-track-meta" x-text="trackDuration(track.duration_seconds)"></div>
+                                    <button class="icon-btn" type="button" @click="removeReleaseTrack(track.id)" title="Remove from release">
+                                        <i data-lucide="x"></i>
+                                    </button>
+                                </div>
+                            </template>
+                        </div>
+                        <div class="empty" x-show="!releaseTracks().length">No tracks attached</div>
+                    </div>
+
                     <div class="editor-grid" x-show="isTrackEditor()">
                         <div class="field">
                             <label>Track #</label>
@@ -2585,9 +2809,9 @@ tbody tr:hover {
                     <div class="toolbar">
                         <button class="btn primary" @click="saveLibraryItem()" :disabled="!editorCanSave()">
                             <i :data-lucide="editorSaving ? 'loader-circle' : 'save'"></i>
-                            <span x-text="editorSaving ? 'Saving...' : 'Save'"></span>
+                            <span x-text="editorSaving ? 'Saving...' : (editorIsNewRelease() ? 'Create' : 'Save')"></span>
                         </button>
-                        <button class="btn danger" @click="deleteLibraryItem(activeLibraryItem)" :disabled="editorSaving || editorImageUploading">
+                        <button class="btn danger" x-show="!editorIsNewRelease()" @click="deleteLibraryItem(activeLibraryItem)" :disabled="editorSaving || editorImageUploading">
                             <i data-lucide="trash-2"></i>
                             Delete
                         </button>
@@ -2682,8 +2906,12 @@ function adminV2() {
         editorImageFile: null,
         editorArtistToAdd: '',
         editorReleaseToAdd: '',
+        releaseTrackSearch: '',
+        releaseTrackSearchResults: [],
+        releaseTrackSearchLoading: false,
+        releaseTrackSearchToken: 0,
         editorDetail: null,
-        editorDraft: { title: '', hidden: 'false', release_type: 'album', year: '', release_id: null, track_number: '', disc_number: '', artist_ids: [] },
+        editorDraft: { title: '', hidden: 'false', release_type: 'album', year: '', release_id: null, track_number: '', disc_number: '', artist_ids: [], release_tracks: [] },
         settings: { values: {}, sources: {}, lastfm_api_key_configured: false, lastfm_shared_secret_configured: false, lastfm_scrobbling_configured: false },
         settingsDraft: {
             auth_password_enabled: false,
@@ -2705,10 +2933,17 @@ function adminV2() {
             agent_llm_auth: '',
             agent_confidence_threshold: '',
             agent_context_limit: '',
-            agent_concurrency: ''
+            agent_concurrency: '',
+            federation_enabled: false,
+            federation_network_id: '',
+            federation_save_on_listen: false
         },
         settingsProbe: { status: 'idle', ok: false },
         settingsProbeLoading: false,
+        federationStatus: {},
+        federationLoading: false,
+        federationTicket: '',
+        fedConnectTicket: '',
         settingsSaving: false,
         routeReady: false,
         poller: null,
@@ -2988,6 +3223,7 @@ function adminV2() {
                     body: JSON.stringify(this.settingsDraft)
                 });
                 await this.loadSettings(false);
+                await this.loadFederation(false);
                 this.showToast('Settings saved');
             } catch (error) {
                 this.showToast(error.message);
@@ -3001,11 +3237,87 @@ function adminV2() {
             this.activeView = 'settings';
             this.setRoute('#settings');
             await this.loadSettings();
+            await this.loadFederation(false);
             if (!this.settingsProbe.status || this.settingsProbe.status === 'idle') {
                 await this.loadSettingsProbe(false);
             }
         },
 
+        async loadFederation(showErrors = true) {
+            this.federationLoading = true;
+            try {
+                this.federationStatus = await this.request(`${this.apiBase}/federation`);
+            } catch (error) {
+                if (showErrors) this.showToast(error.message);
+            } finally {
+                this.federationLoading = false;
+                this.icons();
+            }
+        },
+
+        async fedSyncNow() {
+            this.federationLoading = true;
+            try {
+                this.federationStatus = await this.request(`${this.apiBase}/federation/sync`, { method: 'POST', body: '{}' });
+                this.showToast('Library published to the federation');
+            } catch (error) {
+                this.showToast(error.message);
+            } finally {
+                this.federationLoading = false;
+                this.icons();
+            }
+        },
+
+        async fedShowTicket() {
+            this.federationLoading = true;
+            try {
+                const data = await this.request(`${this.apiBase}/federation/ticket`);
+                this.federationTicket = data.ticket || '';
+            } catch (error) {
+                this.showToast(error.message);
+            } finally {
+                this.federationLoading = false;
+                this.icons();
+            }
+        },
+
+        async fedConnect() {
+            this.federationLoading = true;
+            try {
+                const data = await this.request(`${this.apiBase}/federation/connect`, {
+                    method: 'POST',
+                    body: JSON.stringify({ ticket: this.fedConnectTicket.trim() })
+                });
+                this.fedConnectTicket = '';
+                this.showToast(`Connected to ${(data.connected || '').slice(0, 12)}…`);
+                await this.loadFederation(false);
+            } catch (error) {
+                this.showToast(error.message);
+            } finally {
+                this.federationLoading = false;
+                this.icons();
+            }
+        },
+
+        fedShort(id) {
+            return id ? `${id.slice(0, 12)}…` : '-';
+        },
+
+        fedTransport() {
+            return (this.federationStatus.node && this.federationStatus.node.transport) || {};
+        },
+
+        fedPathBadge(path) {
+            if (path === 'direct') return 'ok';
+            if (path === 'relay') return 'pending';
+            if (path === 'custom') return 'running';
+            return 'disabled';
+        },
+
+        fedRtt(ms) {
+            return ms != null ? `${Math.round(Number(ms))} ms` : '-';
+        },
+
         async loadSettingsProbe(showErrors = true) {
             this.settingsProbeLoading = true;
             try {
@@ -3396,16 +3708,30 @@ function adminV2() {
                 release_id: null,
                 track_number: '',
                 disc_number: '',
-                artist_ids: []
+                artist_ids: [],
+                release_tracks: []
             };
             this.editorDetail = null;
             this.editorImageFile = null;
             this.editorArtistToAdd = '';
             this.editorReleaseToAdd = '';
+            this.clearReleaseTrackSearch();
             this.editorOpen = true;
             this.loadEditorDetail(item);
         },
 
+        openReleaseCreator() {
+            this.libraryKind = 'releases';
+            this.openEditor({
+                id: 0,
+                kind: 'releases',
+                title: '',
+                subtitle: 'New release',
+                is_hidden: false,
+                tags: []
+            });
+        },
+
         async loadEditorDetail(item) {
             const key = `${item.kind}:${item.id}`;
             this.editorLoading = true;
@@ -3422,11 +3748,13 @@ function adminV2() {
                     release_id: detail.release_id || null,
                     track_number: detail.track_number || '',
                     disc_number: detail.disc_number || '',
-                    artist_ids: Array.isArray(detail.selected_artist_ids) ? detail.selected_artist_ids.slice() : []
+                    artist_ids: Array.isArray(detail.selected_artist_ids) ? detail.selected_artist_ids.slice() : [],
+                    release_tracks: Array.isArray(detail.release_tracks) ? detail.release_tracks.map(track => this.normalizeReleaseTrack(track)) : []
                 };
                 this.editorImageFile = null;
                 this.editorArtistToAdd = '';
                 this.editorReleaseToAdd = '';
+                this.clearReleaseTrackSearch();
             } catch (error) {
                 this.showToast(error.message);
             } finally {
@@ -3449,8 +3777,22 @@ function adminV2() {
             return this.activeLibraryItem && this.activeLibraryItem.kind === 'tracks';
         },
 
+        editorIsNewRelease() {
+            return this.isReleaseEditor() && Number(this.activeLibraryItem.id || 0) === 0;
+        },
+
+        editorTitle() {
+            if (this.editorIsNewRelease()) return 'New release';
+            return this.activeLibraryItem?.title || 'Editor';
+        },
+
+        editorSubtitle() {
+            if (this.editorIsNewRelease()) return 'Create release and attach tracks';
+            return this.activeLibraryItem?.kind || 'Library entity';
+        },
+
         canEditLibraryImage() {
-            return this.isArtistEditor() || this.isReleaseEditor();
+            return this.isArtistEditor() || (this.isReleaseEditor() && !this.editorIsNewRelease());
         },
 
         canShowMetadataTags() {
@@ -3497,6 +3839,7 @@ function adminV2() {
 
         editorCanSave() {
             if (!this.activeLibraryItem || !this.editorDetail || this.editorLoading || this.editorSaving) return false;
+            if (!String(this.editorDraft.title || '').trim()) return false;
             if (this.isTrackEditor() && !this.editorDraft.release_id) return false;
             return true;
         },
@@ -3605,6 +3948,146 @@ function adminV2() {
             return true;
         },
 
+        normalizeReleaseTrack(track = {}) {
+            const trackNumber = track.track_number;
+            const discNumber = track.disc_number;
+            return {
+                id: Number(track.id),
+                title: track.title || `Track #${track.id}`,
+                artists: track.artists || '',
+                release_id: track.release_id == null ? null : Number(track.release_id),
+                release_title: track.release_title || '',
+                track_number: trackNumber == null ? '' : String(trackNumber),
+                disc_number: discNumber == null ? '' : String(discNumber),
+                duration_seconds: Number(track.duration_seconds || 0),
+                is_hidden: Boolean(track.is_hidden)
+            };
+        },
+
+        releaseTracks() {
+            if (!Array.isArray(this.editorDraft.release_tracks)) {
+                this.editorDraft.release_tracks = [];
+            }
+            return this.editorDraft.release_tracks;
+        },
+
+        releaseTrackPayload() {
+            return this.releaseTracks().map(track => ({
+                id: Number(track.id),
+                track_number: track.track_number || '',
+                disc_number: track.disc_number || ''
+            }));
+        },
+
+        releaseTrackIds() {
+            return new Set(this.releaseTracks().map(track => Number(track.id)));
+        },
+
+        releaseTrackSearchOpen() {
+            return this.isReleaseEditor() && String(this.releaseTrackSearch || '').trim().length > 0;
+        },
+
+        availableReleaseTrackResults() {
+            const selected = this.releaseTrackIds();
+            return (this.releaseTrackSearchResults || []).filter(track => !selected.has(Number(track.id)));
+        },
+
+        clearReleaseTrackSearch() {
+            this.releaseTrackSearch = '';
+            this.releaseTrackSearchResults = [];
+            this.releaseTrackSearchLoading = false;
+            this.releaseTrackSearchToken += 1;
+        },
+
+        async searchReleaseTracks() {
+            const query = String(this.releaseTrackSearch || '').trim();
+            if (!query) {
+                this.releaseTrackSearchResults = [];
+                this.releaseTrackSearchLoading = false;
+                return;
+            }
+            const token = this.releaseTrackSearchToken + 1;
+            this.releaseTrackSearchToken = token;
+            this.releaseTrackSearchLoading = true;
+            try {
+                const params = new URLSearchParams({ search: query, limit: '16' });
+                const rows = await this.request(`${this.apiBase}/library/tracks/search?${params.toString()}`);
+                if (this.releaseTrackSearchToken !== token) return;
+                this.releaseTrackSearchResults = Array.isArray(rows) ? rows.map(track => this.normalizeReleaseTrack(track)) : [];
+            } catch (error) {
+                if (this.releaseTrackSearchToken === token) this.showToast(error.message);
+            } finally {
+                if (this.releaseTrackSearchToken === token) {
+                    this.releaseTrackSearchLoading = false;
+                    this.icons();
+                }
+            }
+        },
+
+        async addBestReleaseTrack() {
+            if (!String(this.releaseTrackSearch || '').trim()) return;
+            if (!this.availableReleaseTrackResults().length && !this.releaseTrackSearchLoading) {
+                await this.searchReleaseTracks();
+            }
+            const track = this.availableReleaseTrackResults()[0];
+            if (!track) {
+                this.showToast('Choose a track from search results');
+                return;
+            }
+            this.addReleaseTrack(track);
+        },
+
+        addReleaseTrack(track) {
+            if (!track) return;
+            const normalized = this.normalizeReleaseTrack(track);
+            if (this.releaseTrackIds().has(Number(normalized.id))) {
+                this.showToast('Track already in release');
+                return;
+            }
+            this.editorDraft.release_tracks = this.releaseTracks().concat([normalized]);
+            this.clearReleaseTrackSearch();
+            this.$nextTick(() => this.icons());
+        },
+
+        removeReleaseTrack(id) {
+            this.editorDraft.release_tracks = this.releaseTracks().filter(track => Number(track.id) !== Number(id));
+        },
+
+        releaseTrackOrigin(track) {
+            const releaseId = Number(track && track.release_id ? track.release_id : 0);
+            const currentId = Number(this.activeLibraryItem && this.activeLibraryItem.id ? this.activeLibraryItem.id : 0);
+            if (releaseId && releaseId === currentId) return this.editorDraft.title || track.release_title || 'This release';
+            if (track && track.release_title) return track.release_title;
+            if (releaseId) return `Missing release #${releaseId}`;
+            return 'No release';
+        },
+
+        releaseTrackSearchMeta(track) {
+            const parts = [];
+            if (track.artists) parts.push(track.artists);
+            parts.push(this.releaseTrackOrigin(track));
+            const number = this.releaseTrackNumberLabel(track);
+            if (number) parts.push(number);
+            return parts.join(' / ');
+        },
+
+        releaseTrackNumberLabel(track) {
+            const disc = String((track && track.disc_number) || '').trim();
+            const number = String((track && track.track_number) || '').trim();
+            if (disc && number) return `D${disc} #${number}`;
+            if (number) return `#${number}`;
+            if (disc) return `D${disc}`;
+            return '';
+        },
+
+        trackDuration(seconds) {
+            const total = Math.round(Number(seconds || 0));
+            if (!total) return '-';
+            const minutes = Math.floor(total / 60);
+            const rest = String(total % 60).padStart(2, '0');
+            return `${minutes}:${rest}`;
+        },
+
         setEditorImageFile(event) {
             this.editorImageFile = event.target.files && event.target.files.length ? event.target.files[0] : null;
         },
@@ -3729,6 +4212,7 @@ function adminV2() {
             if (!this.editorCanSave()) return;
             this.editorSaving = true;
             try {
+                const wasNewRelease = this.editorIsNewRelease();
                 const updated = await this.request(`${this.apiBase}/library/item`, {
                     method: 'POST',
                     body: JSON.stringify({
@@ -3741,13 +4225,15 @@ function adminV2() {
                         release_id: this.editorDraft.release_id ? Number(this.editorDraft.release_id) : null,
                         track_number: this.editorDraft.track_number || '',
                         disc_number: this.editorDraft.disc_number || '',
-                        artist_ids: this.editorDraft.artist_ids || []
+                        artist_ids: this.editorDraft.artist_ids || [],
+                        release_tracks: this.isReleaseEditor() ? this.releaseTrackPayload() : null
                     })
                 });
                 this.replaceLibraryItem(updated);
                 this.activeLibraryItem = updated;
                 if (this.editorDetail) this.editorDetail.item = updated;
-                this.showToast('Saved');
+                if (this.isReleaseEditor()) await this.loadEditorDetail(updated);
+                this.showToast(wasNewRelease ? 'Release created' : 'Saved');
                 await this.refreshCountsOnly();
             } catch (error) {
                 this.showToast(error.message);
@@ -3768,9 +4254,18 @@ function adminV2() {
         },
 
         replaceLibraryItem(updated) {
-            this.library.items = this.library.items.map(item =>
-                item.kind === updated.kind && item.id === updated.id ? updated : item
-            );
+            let replaced = false;
+            this.library.items = this.library.items.map(item => {
+                if (item.kind === updated.kind && Number(item.id) === Number(updated.id)) {
+                    replaced = true;
+                    return updated;
+                }
+                return item;
+            });
+            if (!replaced && updated.kind === this.libraryKind) {
+                this.library.items = [updated].concat(this.library.items || []);
+                this.library.total = Number(this.library.total || 0) + 1;
+            }
         },
 
         async refreshCountsOnly() {

templates/base.html

@@ -3,6 +3,7 @@
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <link rel="icon" type="image/svg+xml" href="data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 64 64'%3E%3Crect width='64' height='64' rx='14' fill='%23111827'/%3E%3Cpath d='M27 15v31.5a9 9 0 1 1-5-8.1V22l27-6v24.5a9 9 0 1 1-5-8.1V15.9L27 20.5' fill='%2367e8f9'/%3E%3C/svg%3E">
     <title>{% block title %}{{ t.site_name }}{% endblock title %}</title>
     {% block head_extra %}{% endblock head_extra %}
 </head>

templates/player/modals.html

@@ -636,6 +636,144 @@
         </div>
     </template>
 
+    <!-- User Settings Modal -->
+    <template x-if="$store.user.settingsOpen">
+        <div class="modal-overlay" @click.self="$store.user.closeSettings()">
+            <div class="modal-box user-settings-modal">
+                <div class="user-settings-head">
+                    <div>
+                        <h3>User settings</h3>
+                        <p>Personal services, listening history and trusted devices.</p>
+                    </div>
+                    <button class="mobile-list-action" @click="$store.user.closeSettings()" title="{{ t.player_close }}">
+                        <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                            <line x1="18" y1="6" x2="6" y2="18"/>
+                            <line x1="6" y1="6" x2="18" y2="18"/>
+                        </svg>
+                    </button>
+                </div>
+
+                <section class="user-settings-section">
+                    <div class="user-settings-section-head">
+                        <div>
+                            <h4>Listening history</h4>
+                            <p>Review plays recorded by this web player.</p>
+                        </div>
+                        <button class="settings-secondary-btn" @click="$store.user.openHistoryFromSettings()">Open history</button>
+                    </div>
+                </section>
+
+                <section class="user-settings-section">
+                    <div class="user-settings-section-head">
+                        <div>
+                            <h4>Last.fm</h4>
+                            <p x-text="$store.user.lastfmStatusLabel()"></p>
+                        </div>
+                        <button class="settings-secondary-btn"
+                                :class="$store.user.lastfmClass()"
+                                :disabled="$store.user.lastfmBusy || !$store.user.lastfm?.configured"
+                                @click="$store.user.handleLastfm()"
+                                x-text="$store.user.lastfm?.connected && !$store.user.lastfm?.reauth_required ? 'Disconnect' : 'Connect'"></button>
+                    </div>
+                </section>
+
+                <section class="user-settings-section user-settings-devices">
+                    <div class="user-settings-section-head">
+                        <div>
+                            <h4>Connected devices</h4>
+                            <p x-text="$store.devices.fedSummary()"></p>
+                        </div>
+                        <button class="settings-secondary-btn"
+                                :disabled="$store.devices.fedBusy"
+                                @click="$store.devices.syncFedDevices()">Sync now</button>
+                    </div>
+                    <template x-if="$store.devices.fedError">
+                        <div class="fed-device-error" x-text="$store.devices.fedError"></div>
+                    </template>
+
+                    <div class="settings-device-group">
+                        <div class="settings-device-label">Web player sessions</div>
+                        <template x-for="device in $store.devices.webDevices()" :key="'settings-web-' + device.id">
+                            <div class="settings-device-row">
+                                <span class="device-row-icon">
+                                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                                        <rect x="3" y="4" width="18" height="12" rx="2"/>
+                                        <path d="M8 20h8M12 16v4"/>
+                                    </svg>
+                                </span>
+                                <span class="fed-device-main">
+                                    <span class="fed-device-name" x-text="device.name"></span>
+                                    <span class="fed-device-meta"
+                                          x-text="device.is_current ? 'This browser session' : (device.is_active ? 'Active web session' : 'Web session')"></span>
+                                </span>
+                            </div>
+                        </template>
+                    </div>
+
+                    <div class="settings-device-group">
+                        <div class="settings-device-label">Trusted federation devices</div>
+                        <template x-for="request in $store.devices.fedPending()" :key="request.request_id">
+                            <div class="fed-pairing-card">
+                                <div class="fed-pairing-title" x-text="request.name || request.device_id"></div>
+                                <div class="fed-pairing-meta"
+                                     x-text="request.requester_group_id ? 'Already belongs to another sync group' : (request.client_version || 'Waiting for approval')"></div>
+                                <div class="fed-device-actions">
+                                    <button class="fed-action-btn primary"
+                                            @click="$store.devices.answerFedPairing(request, true, !!request.requester_group_id)"
+                                            x-text="request.requester_group_id ? 'Use existing group' : 'Approve'"></button>
+                                    <button class="fed-action-btn"
+                                            @click="$store.devices.answerFedPairing(request, false, false)">Reject</button>
+                                </div>
+                            </div>
+                        </template>
+                        <template x-for="device in $store.devices.fedDevices()" :key="'settings-fed-' + device.device_id">
+                            <div class="settings-device-row federation">
+                                <span class="device-row-icon federation-device-icon">
+                                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8">
+                                        <circle cx="12" cy="12" r="3"/>
+                                        <path d="M5.6 8.5a7.5 7.5 0 000 7M18.4 8.5a7.5 7.5 0 010 7"/>
+                                        <path d="M2.8 5.8a11 11 0 000 12.4M21.2 5.8a11 11 0 010 12.4"/>
+                                    </svg>
+                                </span>
+                                <span class="fed-device-main">
+                                    <span class="fed-device-name" x-text="device.name || device.device_id"></span>
+                                    <span class="fed-device-meta"
+                                          x-text="device.is_self ? 'This web player' : (device.client_version || 'Trusted device')"></span>
+                                </span>
+                                <button class="fed-revoke-btn"
+                                        x-show="!device.is_self"
+                                        :disabled="$store.devices.fedBusy"
+                                        @click="$store.devices.revokeFedDevice(device)">Revoke</button>
+                            </div>
+                        </template>
+                    </div>
+
+                    <div class="settings-pairing-actions">
+                        <button class="settings-primary-btn"
+                                :disabled="$store.devices.fedBusy"
+                                @click="$store.devices.generateFedInvite()">Invite a device</button>
+                        <template x-if="$store.devices.fedInvite">
+                            <input class="fed-device-input"
+                                   readonly
+                                   :value="$store.devices.fedInvite"
+                                   @focus="$event.target.select()">
+                        </template>
+                        <div class="fed-connect-row">
+                            <input class="fed-device-input"
+                                   type="text"
+                                   placeholder="Paste frid:// invite"
+                                   x-model="$store.devices.fedInviteInput"
+                                   @keydown.enter.prevent="$store.devices.connectFedInvite()">
+                            <button class="settings-secondary-btn"
+                                    :disabled="$store.devices.fedBusy || !$store.devices.fedInviteInput.trim()"
+                                    @click="$store.devices.connectFedInvite()">Connect</button>
+                        </div>
+                    </div>
+                </section>
+            </div>
+        </div>
+    </template>
+
     <!-- Play History Modal -->
     <template x-if="$store.history.modal">
         <div class="modal-overlay" @click.self="$store.history.close()">
@@ -683,7 +821,12 @@
                                 </template>
                             </button>
                             <div class="track-info">
-                                <div class="track-title" x-text="item.track?.title || item.track_title"></div>
+                                <div class="track-title">
+                                    <span x-text="item.track?.title || item.track_title"></span>
+                                    <span class="history-device-badge"
+                                          :title="item.device_id"
+                                          x-text="item.device_name"></span>
+                                </div>
                                 <div class="track-artists-inline">
                                     <template x-for="(artist, artistIdx) in $store.library.trackArtistLinks(item.track)" :key="artist.label + '-' + artist.id + '-' + artistIdx">
                                         <span>

templates/player/styles.html

@@ -67,11 +67,17 @@ body {
 
 .user-widget-main {
     display: grid;
-    grid-template-columns: 36px minmax(0, 1fr) 32px;
+    grid-template-columns: 36px minmax(0, 1fr) auto;
     align-items: center;
     gap: 10px;
 }
 
+.user-widget-actions {
+    display: flex;
+    align-items: center;
+    gap: 2px;
+}
+
 .user-avatar {
     width: 36px;
     height: 36px;
@@ -489,6 +495,25 @@ button.user-stat:hover {
     font-size: 13px;
 }
 
+.playlist-detail-heading {
+    display: flex;
+    align-items: flex-start;
+    justify-content: space-between;
+    gap: 12px;
+    margin-bottom: 14px;
+}
+
+.playlist-detail-heading .section-title {
+    min-width: 0;
+    margin-bottom: 0;
+    overflow-wrap: anywhere;
+}
+
+.playlist-edit-toggle {
+    flex: 0 0 auto;
+    margin-top: 4px;
+}
+
 .breadcrumb {
     display: flex;
     align-items: center;
@@ -651,6 +676,42 @@ button.user-stat:hover {
     margin-bottom: 14px;
     text-transform: capitalize;
 }
+.artist-release-group-heading {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 16px;
+    margin-bottom: 14px;
+}
+.artist-release-group-heading .artist-release-group-title {
+    margin-bottom: 0;
+}
+.artist-top-tracks-toggle {
+    border: 0;
+    background: transparent;
+    color: var(--text-subdued);
+    display: inline-flex;
+    align-items: center;
+    gap: 6px;
+    padding: 5px 7px;
+    border-radius: 5px;
+    font: inherit;
+    font-size: 12px;
+    font-weight: 700;
+    cursor: pointer;
+}
+.artist-top-tracks-toggle:hover {
+    color: var(--text-primary);
+    background: var(--bg-hover);
+}
+.artist-top-tracks-toggle svg {
+    width: 15px;
+    height: 15px;
+    transition: transform 0.18s ease;
+}
+.artist-top-tracks-toggle svg.expanded {
+    transform: rotate(180deg);
+}
 
 /* Release detail header */
 .release-header {
@@ -735,6 +796,93 @@ button.user-stat:hover {
 .track-row:hover { background: var(--bg-hover); }
 .track-row.playing { color: var(--accent); }
 .track-row.playing .track-num { color: var(--accent); }
+.playlist-track-list-header.editing,
+.playlist-track-row.editing {
+    grid-template-columns: 32px 40px minmax(0, 1fr) minmax(0, 1fr) 154px 60px;
+}
+
+.playlist-track-row.editing {
+    cursor: grab;
+}
+
+.playlist-track-row.editing:active {
+    cursor: grabbing;
+}
+
+.playlist-track-row.dragging {
+    opacity: 0.45;
+}
+
+.playlist-track-row.drag-over {
+    border-top: 2px solid var(--accent);
+    margin-top: -2px;
+}
+
+.playlist-track-remove {
+    width: 28px;
+    height: 28px;
+    border: 0;
+    border-radius: 4px;
+    background: transparent;
+    color: var(--text-subdued);
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    padding: 0;
+    transition: color 0.15s, background 0.15s;
+}
+
+.playlist-track-remove:hover {
+    color: var(--text-primary);
+    background: var(--bg-active);
+}
+
+.playlist-track-remove svg {
+    width: 16px;
+    height: 16px;
+}
+
+.playlist-track-info {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+}
+
+.playlist-track-copy {
+    min-width: 0;
+    overflow: hidden;
+}
+
+.playlist-drag-handle {
+    width: 24px;
+    height: 28px;
+    border: 0;
+    background: transparent;
+    color: var(--text-subdued);
+    cursor: grab;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    flex: 0 0 24px;
+    padding: 0;
+    touch-action: none;
+    user-select: none;
+}
+
+.playlist-drag-handle:active {
+    cursor: grabbing;
+}
+
+.playlist-drag-handle:hover {
+    color: var(--text-primary);
+}
+
+.playlist-drag-handle svg {
+    width: 14px;
+    height: 14px;
+}
+
 .track-row.shared-target {
     background: rgba(29, 185, 84, 0.12);
     box-shadow: inset 3px 0 0 var(--accent);
@@ -1224,7 +1372,22 @@ button.user-stat:hover {
 }
 
 .queue-track:hover { background: var(--bg-hover); }
-.queue-track.active { background: var(--bg-active); }
+.queue-track.active,
+.queue-track.current { background: var(--bg-active); }
+.queue-track.played {
+    color: var(--text-subdued);
+    opacity: 0.58;
+}
+.queue-track.played:hover {
+    opacity: 0.78;
+}
+.queue-track.played .queue-track-cover {
+    filter: grayscale(1);
+    opacity: 0.72;
+}
+.queue-track.synthetic .queue-drag-handle {
+    display: none;
+}
 .queue-track.foreign-jam-track {
     background: linear-gradient(90deg, var(--jam-contributor-bg, rgba(82,145,255,0.12)), transparent 78%);
 }
@@ -1236,20 +1399,50 @@ button.user-stat:hover {
 }
 
 .queue-track-cover {
+    position: relative;
     width: 40px;
     height: 40px;
     border-radius: 4px;
     background: var(--bg-elevated);
-    overflow: hidden;
+    overflow: visible;
     flex-shrink: 0;
     display: flex;
     align-items: center;
     justify-content: center;
 }
 
-.queue-track-cover img { width: 100%; height: 100%; object-fit: cover; }
+.queue-track-cover img { width: 100%; height: 100%; object-fit: cover; border-radius: inherit; }
 .queue-track-cover svg { width: 20px; height: 20px; color: var(--text-subdued); }
 
+.queue-track-cover .queue-federation-status {
+    position: absolute;
+    right: 2px;
+    bottom: 2px;
+    z-index: 3;
+    width: 18px;
+    min-width: 18px;
+    max-width: 18px;
+    height: 18px;
+    min-height: 18px;
+    max-height: 18px;
+    box-sizing: border-box;
+    flex: none;
+    border-radius: 50%;
+    background: var(--bg-elevated);
+    box-shadow: 0 0 0 1px var(--bg-secondary);
+}
+.queue-track-cover .queue-federation-status > svg {
+    width: 13px;
+    height: 13px;
+}
+.queue-track-cover .queue-federation-status .federation-download-progress,
+.queue-track-cover .queue-federation-status .federation-download-progress svg {
+    width: 18px !important;
+    min-width: 18px;
+    height: 18px !important;
+    min-height: 18px;
+}
+
 .queue-track-info { overflow: hidden; flex: 1; }
 .queue-track-title {
     font-size: 13px;
@@ -1259,7 +1452,9 @@ button.user-stat:hover {
     text-overflow: ellipsis;
 }
 
-.queue-track.active .queue-track-title { color: var(--accent); }
+.queue-track.active .queue-track-title,
+.queue-track.current .queue-track-title { color: var(--accent); }
+.queue-track.played .queue-track-title { color: var(--text-subdued); }
 
 .queue-track-artist {
     font-size: 11px;
@@ -1733,9 +1928,9 @@ button.user-stat:hover {
     position: absolute;
     right: 0;
     bottom: 38px;
-    width: 260px;
+    width: 320px;
     max-width: calc(100vw - 24px);
-    max-height: min(320px, calc(100dvh - var(--player-bar-space) - 24px));
+    max-height: min(440px, calc(100dvh - var(--player-bar-space) - 24px));
     overflow-y: auto;
     padding: 6px;
     border: 1px solid var(--border-color);
@@ -1832,6 +2027,169 @@ button.user-stat:hover {
     text-transform: uppercase;
 }
 
+.device-group-divider {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    margin: 7px 8px 3px;
+    color: #b8d6ff;
+    font-size: 10px;
+    font-weight: 750;
+    text-transform: uppercase;
+}
+.device-group-divider::before,
+.device-group-divider::after {
+    content: "";
+    height: 1px;
+    flex: 1;
+    background: var(--border-color);
+}
+.device-group-divider span {
+    white-space: nowrap;
+}
+.federation-device-row {
+    color: #c9dcff;
+}
+.federation-device-icon {
+    color: #78a9ff;
+}
+
+.fed-section-label {
+    margin-top: 4px;
+    color: #b8d6ff;
+}
+
+.fed-device-panel {
+    margin: 2px 2px 6px;
+    padding: 8px;
+    border: 1px solid rgba(82,145,255,0.18);
+    border-radius: 6px;
+    background: rgba(82,145,255,0.045);
+    display: grid;
+    gap: 7px;
+}
+
+.fed-device-status,
+.fed-device-error,
+.fed-pairing-note {
+    color: var(--text-subdued);
+    font-size: 11px;
+    line-height: 1.35;
+}
+
+.fed-device-error {
+    color: #ffb2b2;
+}
+
+.fed-device-row {
+    min-height: 32px;
+    display: grid;
+    grid-template-columns: 9px minmax(0, 1fr) auto;
+    align-items: center;
+    gap: 8px;
+}
+
+.fed-device-dot {
+    width: 7px;
+    height: 7px;
+    border-radius: 999px;
+    background: #73d795;
+}
+
+.fed-device-dot.self {
+    background: #ffd166;
+}
+
+.fed-device-main {
+    min-width: 0;
+    display: grid;
+    gap: 1px;
+}
+
+.fed-device-name,
+.fed-pairing-title {
+    color: var(--text-primary);
+    font-size: 12px;
+    font-weight: 750;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+
+.fed-device-meta,
+.fed-pairing-meta {
+    color: var(--text-subdued);
+    font-size: 11px;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+
+.fed-pairing-card {
+    padding: 7px;
+    border-radius: 5px;
+    background: rgba(255,255,255,0.04);
+    display: grid;
+    gap: 5px;
+}
+
+.fed-device-actions,
+.fed-connect-row {
+    display: flex;
+    gap: 6px;
+    min-width: 0;
+}
+
+.fed-connect-row .fed-device-input {
+    flex: 1;
+}
+
+.fed-action-btn,
+.fed-revoke-btn {
+    height: 28px;
+    border: 0;
+    border-radius: 4px;
+    background: rgba(255,255,255,0.08);
+    color: var(--text-secondary);
+    padding: 0 8px;
+    font-size: 12px;
+    font-weight: 700;
+    cursor: pointer;
+}
+
+.fed-action-btn:hover,
+.fed-revoke-btn:hover {
+    background: rgba(255,255,255,0.13);
+    color: var(--text-primary);
+}
+
+.fed-action-btn.primary {
+    background: rgba(82,145,255,0.16);
+    color: #c9dcff;
+}
+
+.fed-action-btn:disabled {
+    opacity: 0.45;
+    cursor: default;
+}
+
+.fed-revoke-btn {
+    background: rgba(255,96,96,0.1);
+    color: #ffb2b2;
+}
+
+.fed-device-input {
+    width: 100%;
+    min-width: 0;
+    height: 30px;
+    border: 1px solid rgba(82,145,255,0.2);
+    border-radius: 4px;
+    background: rgba(0,0,0,0.18);
+    color: var(--text-primary);
+    padding: 0 8px;
+    font-size: 12px;
+}
+
 .jam-section-label,
 .jam-row,
 .start-jam-row,
@@ -2115,7 +2473,16 @@ button.user-stat:hover {
     line-height: 1;
     font-weight: 500;
     text-align: center;
-    pointer-events: none;
+    text-decoration: none;
+    pointer-events: auto;
+    transition: opacity 120ms ease;
+}
+
+.player-version-chip:hover,
+.player-version-chip:focus-visible {
+    color: var(--text-subdued);
+    opacity: 0.9;
+    text-decoration: none;
 }
 
 .mobile-account-chip {
@@ -2177,11 +2544,18 @@ button.user-stat:hover {
 }
 
 .mobile-account-logout {
-    width: 100%;
-    margin-top: 12px;
+    flex: 1;
+    margin: 0;
     justify-content: center;
 }
 
+.mobile-account-actions {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    margin-top: 12px;
+}
+
 .torrent-import-btn {
     display: flex;
     align-items: center;
@@ -2373,6 +2747,125 @@ button.user-stat:hover {
 
 /* Search results */
 .search-section { margin-bottom: 24px; }
+.federation-search-section {
+    border-top: 1px solid var(--border);
+    padding-top: 18px;
+}
+.federation-live-badge {
+    margin-left: 8px;
+    color: var(--accent);
+    font-size: 10px;
+    letter-spacing: .12em;
+}
+.federation-search-status {
+    color: var(--text-muted);
+    padding: 12px 0;
+}
+.federation-search-status.error { color: var(--danger, #e66); }
+.federation-track-status {
+    position: relative;
+    z-index: 1;
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+}
+.federation-track-status > svg {
+    width: 18px;
+    height: 18px;
+    color: var(--accent);
+}
+.federation-error-badge {
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    width: 18px;
+    height: 18px;
+    border: 1px solid rgba(235, 105, 105, .7);
+    border-radius: 999px;
+    background: rgba(190, 55, 55, .18);
+    color: #ffb0b0;
+    font-size: 11px;
+    font-weight: 850;
+    line-height: 1;
+    cursor: help;
+}
+.queue-federation-status .federation-error-badge {
+    width: 16px;
+    height: 16px;
+    font-size: 10px;
+}
+.federation-download-progress {
+    position: relative;
+    display: inline-flex;
+    width: 22px;
+    height: 22px;
+    align-items: center;
+    justify-content: center;
+}
+.federation-download-progress svg {
+    width: 22px !important;
+    height: 22px !important;
+    transform: rotate(-90deg);
+    overflow: hidden;
+}
+.federation-download-progress circle {
+    fill: none;
+    stroke-width: 2;
+}
+.federation-download-progress .progress-track {
+    stroke: color-mix(in srgb, var(--text-muted) 28%, transparent);
+}
+.federation-download-progress .progress-value {
+    stroke: var(--accent);
+    stroke-linecap: round;
+    stroke-dasharray: 50.27;
+    transition: stroke-dashoffset 160ms linear;
+}
+.federation-download-progress.indeterminate .progress-value {
+    stroke-dasharray: 12.57 37.70;
+    transform-box: fill-box;
+    transform-origin: center;
+    animation: federation-progress-spin .8s linear infinite;
+}
+.federation-download-progress .progress-percent {
+    position: absolute;
+    color: var(--text);
+    font-size: 7px;
+    font-weight: 700;
+    line-height: 1;
+}
+.federation-download-tooltip {
+    position: absolute;
+    z-index: 1000;
+    left: calc(100% + 10px);
+    top: 50%;
+    width: max-content;
+    max-width: 290px;
+    padding: 6px 8px;
+    border: 1px solid var(--border);
+    border-radius: 6px;
+    background: var(--bg-elevated);
+    box-shadow: 0 6px 18px rgba(0, 0, 0, .28);
+    color: var(--text);
+    font-size: 11px;
+    font-weight: 500;
+    line-height: 1.35;
+    opacity: 0;
+    pointer-events: none;
+    transform: translate(3px, -50%);
+    transition: opacity 120ms ease, transform 120ms ease;
+}
+.federation-download-progress:hover .federation-download-tooltip {
+    opacity: 1;
+    transform: translate(0, -50%);
+}
+@keyframes federation-progress-spin {
+    to { transform: rotate(360deg); }
+}
+.federation-source-count {
+    color: var(--text-muted);
+    font-size: 12px;
+}
 .search-section-title {
     font-size: 18px;
     font-weight: 700;
@@ -2416,7 +2909,7 @@ button.user-stat:hover {
     position: relative;
 }
 
-.search-artist-img img { width: 100%; height: 100%; object-fit: cover; }
+.search-artist-img img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
 .search-artist-img svg { width: 32px; height: 32px; color: var(--text-subdued); }
 
 .search-artist-name {
@@ -3112,6 +3605,105 @@ button.user-stat:hover {
     max-width: 980px;
 }
 
+.user-settings-modal {
+    width: min(760px, calc(100vw - 32px));
+    max-width: 760px;
+    max-height: min(86dvh, 820px);
+    overflow-y: auto;
+}
+.user-settings-head,
+.user-settings-section-head {
+    display: flex;
+    align-items: flex-start;
+    justify-content: space-between;
+    gap: 16px;
+}
+.user-settings-head {
+    margin-bottom: 16px;
+}
+.user-settings-head h3,
+.user-settings-section h4 {
+    margin: 0;
+}
+.user-settings-head p,
+.user-settings-section p {
+    margin: 4px 0 0;
+    color: var(--text-subdued);
+    font-size: 12px;
+    line-height: 1.45;
+}
+.user-settings-section {
+    padding: 16px 0;
+    border-top: 1px solid var(--border-color);
+}
+.user-settings-devices {
+    display: grid;
+    gap: 12px;
+}
+.settings-device-group {
+    overflow: hidden;
+    border: 1px solid var(--border-color);
+    border-radius: 8px;
+    background: var(--bg-primary);
+}
+.settings-device-label {
+    padding: 8px 11px;
+    border-bottom: 1px solid var(--border-color);
+    color: var(--text-subdued);
+    font-size: 10px;
+    font-weight: 800;
+    text-transform: uppercase;
+}
+.settings-device-row {
+    min-height: 48px;
+    padding: 8px 11px;
+    display: grid;
+    grid-template-columns: 28px minmax(0, 1fr) auto;
+    align-items: center;
+    gap: 10px;
+    border-bottom: 1px solid rgba(255, 255, 255, 0.055);
+}
+.settings-device-row:last-child {
+    border-bottom: 0;
+}
+.settings-device-row.federation {
+    background: rgba(82, 145, 255, 0.035);
+}
+.settings-primary-btn,
+.settings-secondary-btn {
+    min-height: 34px;
+    padding: 7px 12px;
+    border: 1px solid var(--border-color);
+    border-radius: 6px;
+    background: var(--bg-hover);
+    color: var(--text-primary);
+    cursor: pointer;
+    font-size: 12px;
+    font-weight: 750;
+    white-space: nowrap;
+}
+.settings-primary-btn {
+    border-color: rgba(82, 145, 255, 0.4);
+    background: rgba(82, 145, 255, 0.18);
+    color: #d5e4ff;
+}
+.settings-primary-btn:hover,
+.settings-secondary-btn:hover {
+    filter: brightness(1.12);
+}
+.settings-primary-btn:disabled,
+.settings-secondary-btn:disabled {
+    cursor: default;
+    opacity: .55;
+}
+.settings-pairing-actions {
+    display: grid;
+    gap: 8px;
+}
+.settings-pairing-actions > .settings-primary-btn {
+    justify-self: start;
+}
+
 .history-head {
     display: flex;
     align-items: flex-start;
@@ -3154,6 +3746,18 @@ button.user-stat:hover {
 }
 
 .history-row:last-child { border-bottom: 0; }
+.history-device-badge {
+    display: inline-block;
+    margin-left: .45rem;
+    padding: .08rem .38rem;
+    border: 1px solid color-mix(in srgb, currentColor 28%, transparent);
+    border-radius: 999px;
+    color: var(--text-muted);
+    font-size: .68rem;
+    font-weight: 500;
+    line-height: 1.2;
+    vertical-align: .12rem;
+}
 
 .history-cover {
     width: 40px;
@@ -4216,6 +4820,16 @@ button.user-stat:hover {
         justify-content: flex-end;
     }
 
+    .playlist-track-list-header.editing,
+    .playlist-track-row.editing {
+        grid-template-columns: 30px 32px minmax(0, 1fr) auto 54px;
+    }
+
+    .playlist-track-list-header.editing span:nth-child(4),
+    .playlist-track-row.editing > span:nth-child(4) {
+        display: none;
+    }
+
     .history-table-head,
     .history-row.track-row {
         grid-template-columns: 44px minmax(0, 1fr) auto;
@@ -4925,6 +5539,28 @@ button.user-stat:hover {
         background: var(--bg-hover);
     }
 
+    .mobile-expanded-queue-row.current {
+        background: var(--bg-active);
+    }
+
+    .mobile-expanded-queue-row.current .mobile-expanded-queue-name {
+        color: var(--accent);
+    }
+
+    .mobile-expanded-queue-row.played {
+        color: var(--text-subdued);
+        opacity: 0.56;
+    }
+
+    .mobile-expanded-queue-row.played:active {
+        opacity: 0.74;
+    }
+
+    .mobile-expanded-queue-row.played .mobile-expanded-queue-cover {
+        filter: grayscale(1);
+        opacity: 0.72;
+    }
+
     .mobile-expanded-queue-row.foreign-jam-track {
         background: linear-gradient(90deg, var(--jam-contributor-bg, rgba(82,145,255,0.12)), transparent 82%);
     }
@@ -5119,6 +5755,26 @@ button.user-stat:hover {
         padding: 10px 6px;
     }
 
+    .playlist-detail-heading {
+        align-items: center;
+        gap: 8px;
+        margin-bottom: 12px;
+    }
+
+    .playlist-edit-toggle {
+        padding: 8px 10px;
+        margin-top: 0;
+    }
+
+    .playlist-track-row.editing {
+        grid-template-columns: 30px minmax(0, 1fr) auto;
+    }
+
+    .playlist-track-row.editing .track-num,
+    .playlist-track-row.editing > span:nth-child(4) {
+        display: none;
+    }
+
     .track-row > span:nth-child(3),
     .track-duration {
         display: none;