Merge local and federated similarity results

src/app/cmdline.rs

@@ -8,7 +8,6 @@ use crate::app::Runtime;
 use crate::app::command::{self, Command, Parsed};
 use crate::app::event::AppEvent;
 use crate::app::state::{AppState, GlobalView, SearchState, Tab};
-use crate::library::models::SearchResults;
 
 const SEARCH_DEBOUNCE: Duration = Duration::from_millis(180);
 const SEARCH_LIMIT: i64 = 12;
@@ -99,6 +98,10 @@ fn set_view_cursor_zero(state: &mut AppState) {
 /// and the receiver drops responses that arrive out of date.
 pub(super) fn schedule_search(state: &mut AppState, runtime: &Runtime) {
     state.search.similarity_source = None;
+    state.search.similarity_source_track = None;
+    state.search.similarity_tracks.clear();
+    state.search.similarity_stats = None;
+    state.search.similarity_error = None;
     let seq = runtime.search_seq.fetch_add(1, Ordering::SeqCst) + 1;
     let query = state.search.query.clone();
     if query.is_empty() {
@@ -160,6 +163,10 @@ pub(super) fn schedule_similarity_search(
         format!("{} — {artist}", track.title)
     };
     state.search.similarity_source = Some(track.id);
+    state.search.similarity_source_track = Some(track.clone());
+    state.search.similarity_tracks.clear();
+    state.search.similarity_stats = None;
+    state.search.similarity_error = None;
     state.search.loading = true;
     state.search.results = None;
     state.search.fed_tracks.clear();
@@ -178,23 +185,10 @@ pub(super) fn schedule_similarity_search(
     let similarity = Arc::clone(&runtime.similarity);
     let tx = runtime.event_tx.clone();
     let track_id = track.id;
-    let source_track = track.clone();
     tokio::task::spawn_blocking(move || {
         let result = similarity
             .search_track(track_id, 49)
-            .map(|(matches, query)| {
+            .map(|(matches, query)| (matches, query));
-                let mut tracks = Vec::with_capacity(1 + matches.len());
-                tracks.push(source_track);
-                tracks.extend(matches.into_iter().map(|found| found.track));
-                (
-                    SearchResults {
-                        artists: Vec::new(),
-                        releases: Vec::new(),
-                        tracks,
-                    },
-                    query,
-                )
-            });
         let (result, query) = match result {
             Ok((results, query)) => (Ok(results), Some(query)),
             Err(err) => (Err(format!("{err:#}")), None),

src/app/event.rs

@@ -36,9 +36,14 @@ pub enum AppEvent {
     /// text search so stale pages cannot overwrite a newer request.
     SimilaritySearchLoaded {
         seq: u64,
-        result: Result<SearchResults, String>,
+        result: Result<Vec<crate::similarity::SimilarTrack>, String>,
         query: Option<crate::similarity::QueryVector>,
     },
+    /// Federated candidates and diagnostics for a track-seeded search.
+    FedSimilaritySearchLoaded {
+        seq: u64,
+        result: Result<crate::federation::FedSimilaritySearchResults, String>,
+    },
     SimilarityStatus(crate::similarity::SimilarityStatus),
     /// `None` is emitted after clearing every stored embedding.
     SimilarityProfileActivated(Option<String>),

src/app/mod.rs

@@ -3348,6 +3348,39 @@ fn handle_app_event(state: &mut AppState, runtime: &mut Runtime, event: AppEvent
                 Err(message) => tracing::warn!(%message, "federated search failed"),
             }
         }
+        AppEvent::FedSimilaritySearchLoaded { seq, result } => {
+            if runtime.search_seq.load(std::sync::atomic::Ordering::SeqCst) != seq {
+                return;
+            }
+            state.search.fed_loading = false;
+            let selected_key = state.global.stack.last().and_then(|view| match view {
+                state::GlobalView::Search { cursor } => state.search.similarity_key(*cursor),
+                _ => None,
+            });
+            match result {
+                Ok(results) => {
+                    let remote = results.tracks.into_iter().map(|hit| {
+                        state::SimilaritySearchHit::Federated {
+                            track: hit.track,
+                            score: hit.score,
+                            embedding_signature: hit.embedding_signature,
+                        }
+                    });
+                    state.search.similarity_tracks.extend(remote);
+                    rank_similarity_search_tracks(
+                        &mut state.search.similarity_tracks,
+                        state.similarity.settings.max_tracks_per_artist,
+                    );
+                    state.search.similarity_stats = Some(results.stats);
+                    state.search.similarity_error = None;
+                }
+                Err(message) => {
+                    tracing::warn!(%message, "federated similarity search failed");
+                    state.search.similarity_error = Some(message);
+                }
+            }
+            restore_similarity_cursor(state, selected_key.as_deref());
+        }
         AppEvent::FedTrackResolved {
             placeholder_id,
             resolve_key,
@@ -3696,7 +3729,20 @@ fn handle_app_event(state: &mut AppState, runtime: &mut Runtime, event: AppEvent
             }
             state.search.loading = false;
             match result {
-                Ok(results) => state.search.results = Some(results),
+                Ok(results) => {
+                    state.search.similarity_tracks = results
+                        .into_iter()
+                        .map(|hit| state::SimilaritySearchHit::Local {
+                            track: hit.track,
+                            score: hit.score,
+                            embedding_signature: hit.embedding_signature,
+                        })
+                        .collect();
+                    rank_similarity_search_tracks(
+                        &mut state.search.similarity_tracks,
+                        state.similarity.settings.max_tracks_per_artist,
+                    );
+                }
                 Err(message) => {
                     state.status_message = Some(format!("similarity search failed: {message}"));
                     return;
@@ -3714,7 +3760,7 @@ fn handle_app_event(state: &mut AppState, runtime: &mut Runtime, event: AppEvent
                         .search_similar(query, 50)
                         .await
                         .map_err(|err| format!("{err:#}"));
-                    let _ = tx.send(AppEvent::FedSearchLoaded { seq, result });
+                    let _ = tx.send(AppEvent::FedSimilaritySearchLoaded { seq, result });
                 });
             }
         }
@@ -4007,6 +4053,135 @@ fn handle_app_event(state: &mut AppState, runtime: &mut Runtime, event: AppEvent
     }
 }
 
+fn rank_similarity_search_tracks(
+    tracks: &mut Vec<state::SimilaritySearchHit>,
+    max_tracks_per_artist: usize,
+) {
+    const RESULT_LIMIT: usize = 49;
+    const MAX_NEAR_DUPLICATE_SIGNATURE_DISTANCE: u32 = 8;
+
+    tracks.sort_by(|left, right| right.score().total_cmp(&left.score()));
+    let candidates = std::mem::take(tracks);
+    let mut content = std::collections::HashSet::new();
+    let mut signatures = Vec::new();
+    let mut artist_counts: std::collections::HashMap<String, usize> = Default::default();
+    for hit in candidates {
+        if !content.insert(hit.content_key()) {
+            continue;
+        }
+        if hit.embedding_signature().is_some_and(|candidate| {
+            signatures.iter().any(|existing| {
+                music_dht::similarity::signature_distance(&candidate, existing)
+                    <= MAX_NEAR_DUPLICATE_SIGNATURE_DISTANCE
+            })
+        }) {
+            continue;
+        }
+        let artist = hit.primary_artist_key();
+        let count = artist_counts.entry(artist.clone()).or_default();
+        if !artist.is_empty() && *count >= max_tracks_per_artist.clamp(1, RESULT_LIMIT) {
+            continue;
+        }
+        *count += 1;
+        if let Some(signature) = hit.embedding_signature() {
+            signatures.push(signature);
+        }
+        tracks.push(hit);
+        if tracks.len() >= RESULT_LIMIT {
+            break;
+        }
+    }
+}
+
+fn restore_similarity_cursor(state: &mut AppState, selected_key: Option<&str>) {
+    let selected_index = selected_key.and_then(|key| state.search.similarity_index_for_key(key));
+    let len = state.search.similarity_len();
+    if let Some(state::GlobalView::Search { cursor }) = state.global.stack.last_mut() {
+        *cursor = selected_index.unwrap_or(*cursor).min(len.saturating_sub(1));
+    }
+}
+
+#[cfg(test)]
+mod similarity_search_tests {
+    use super::*;
+    use crate::library::models::{ArtistRef, TrackItem};
+
+    fn local_hit(id: i64, artist: &str, score: f32, signature: u8) -> state::SimilaritySearchHit {
+        state::SimilaritySearchHit::Local {
+            track: TrackItem {
+                id,
+                title: format!("local {id}"),
+                track_number: None,
+                disc_number: None,
+                duration_seconds: 1.0,
+                artists: vec![ArtistRef {
+                    id,
+                    name: artist.to_string(),
+                }],
+                featured_artists: Vec::new(),
+                release_id: id,
+                release_title: "release".to_string(),
+                release_year: None,
+                file_path: format!("/music/{id}"),
+                content_id: Some(format!("local-{id}")),
+                cover_path: None,
+                audio_format: None,
+                audio_bitrate: None,
+                audio_sample_rate: None,
+                audio_bit_depth: None,
+                file_size_bytes: None,
+                play_count: 0,
+                fed: None,
+            },
+            score,
+            embedding_signature: [signature; music_dht::similarity::SIMILARITY_SIGNATURE_BYTES],
+        }
+    }
+
+    fn remote_hit(artist: &str, score: f32, signature: u8) -> state::SimilaritySearchHit {
+        state::SimilaritySearchHit::Federated {
+            track: crate::federation::FedTrack {
+                item_id: format!("remote-{signature}"),
+                owner: "peer".to_string(),
+                own: false,
+                title: format!("remote {signature}"),
+                artist_names: vec![artist.to_string()],
+                featured_artist_names: Vec::new(),
+                year: None,
+                duration_seconds: Some(1),
+                content_id: Some(format!("remote-{signature}")),
+                release_title: None,
+                track_number: None,
+                disc_number: None,
+            },
+            score,
+            embedding_signature: Some(
+                [signature; music_dht::similarity::SIMILARITY_SIGNATURE_BYTES],
+            ),
+        }
+    }
+
+    #[test]
+    fn similarity_results_rank_local_and_remote_together_with_one_artist_cap() {
+        let mut tracks = vec![
+            local_hit(1, "same artist", 0.70, 1),
+            remote_hit("other artist", 0.90, 2),
+            remote_hit("same artist", 0.80, 3),
+            local_hit(2, "same artist", 0.60, 4),
+        ];
+
+        rank_similarity_search_tracks(&mut tracks, 1);
+
+        assert_eq!(tracks.len(), 2);
+        assert_eq!(tracks[0].score(), 0.90);
+        assert_eq!(tracks[1].score(), 0.80);
+        assert!(matches!(
+            tracks[0],
+            state::SimilaritySearchHit::Federated { .. }
+        ));
+    }
+}
+
 /// Mirror the playback state to the OS now-playing surface. `force` skips
 /// the position throttle (track switches, pauses).
 fn push_media_update(state: &AppState, runtime: &mut Runtime, force: bool) {

src/app/popup.rs

@@ -592,6 +592,36 @@ fn handle_fed_input(
                         state.popup = Some(Popup::FedInput { field, input });
                     }
                 },
+                FedInputField::SimilarityMinimumScore => match value.parse::<f32>() {
+                    Ok(score) if score.is_finite() && (0.0..=1.0).contains(&score) => {
+                        state.similarity.settings.minimum_score = score;
+                        super::perform_effect(
+                            state,
+                            runtime,
+                            crate::app::update::Effect::SimilarityApplySettings,
+                        );
+                    }
+                    _ => {
+                        state.status_message =
+                            Some("minimum similarity must be a number from 0.00 to 1.00".into());
+                        state.popup = Some(Popup::FedInput { field, input });
+                    }
+                },
+                FedInputField::SimilarityMaxTracksPerArtist => match value.parse::<usize>() {
+                    Ok(limit @ 1..=50) => {
+                        state.similarity.settings.max_tracks_per_artist = limit;
+                        super::perform_effect(
+                            state,
+                            runtime,
+                            crate::app::update::Effect::SimilarityApplySettings,
+                        );
+                    }
+                    _ => {
+                        state.status_message =
+                            Some("tracks per artist must be a number from 1 to 50".into());
+                        state.popup = Some(Popup::FedInput { field, input });
+                    }
+                },
                 FedInputField::ConnectTicket => {
                     if value.is_empty() {
                         state.status_message = Some("ticket is empty".into());

src/app/state.rs

@@ -509,6 +509,8 @@ pub enum TrackSelectionScope {
     Release(i64),
     Playlist(i64),
     Queue,
+    /// The unified local + federated similar-track result list.
+    SimilaritySearch,
     /// The federated section of the search results (its tracks).
     FedSearch,
     /// The tracklist of the open federated release view.
@@ -817,6 +819,8 @@ impl StatusDetailFocus {
 pub enum FedInputField {
     MusicDirectory,
     SimilarityWorkers,
+    SimilarityMinimumScore,
+    SimilarityMaxTracksPerArtist,
     NetworkId,
     ConnectTicket,
     DeviceName,
@@ -829,6 +833,8 @@ impl FedInputField {
         match self {
             FedInputField::MusicDirectory => "Music save directory",
             FedInputField::SimilarityWorkers => "Similarity background workers",
+            FedInputField::SimilarityMinimumScore => "Minimum similarity score",
+            FedInputField::SimilarityMaxTracksPerArtist => "Tracks per artist",
             FedInputField::NetworkId => "Network ID",
             FedInputField::ConnectTicket => "Connect to peer (paste ticket)",
             FedInputField::DeviceName => "Device name",
@@ -845,6 +851,12 @@ impl FedInputField {
             FedInputField::SimilarityWorkers => {
                 "Enter the maximum number of tracks processed in parallel, from 1 to 16. The change takes effect immediately."
             }
+            FedInputField::SimilarityMinimumScore => {
+                "Enter the minimum cosine similarity from 0.00 to 1.00. Lower values show broader matches; higher values hide weak matches. Embeddings are not recalculated."
+            }
+            FedInputField::SimilarityMaxTracksPerArtist => {
+                "Enter how many tracks by one primary artist may appear in similarity results, from 1 to 50. Embeddings are not recalculated."
+            }
             FedInputField::NetworkId => {
                 "A unique network id. It must match exactly on every client that should see and connect to the same peers."
             }
@@ -880,15 +892,19 @@ pub enum SimilarityRow {
     Toggle,
     Model,
     Profile,
+    MinimumScore,
+    MaxTracksPerArtist,
     Workers,
     Clear,
 }
 
 impl SimilarityRow {
-    pub const ALL: [SimilarityRow; 5] = [
+    pub const ALL: [SimilarityRow; 7] = [
         SimilarityRow::Toggle,
         SimilarityRow::Model,
         SimilarityRow::Profile,
+        SimilarityRow::MinimumScore,
+        SimilarityRow::MaxTracksPerArtist,
         SimilarityRow::Workers,
         SimilarityRow::Clear,
     ];
@@ -1211,6 +1227,85 @@ mod cmdline_history_tests {
 }
 
 /// Live search state driven by the `:/query` command.
+#[derive(Debug, Clone)]
+pub enum SimilaritySearchHit {
+    Local {
+        track: TrackItem,
+        score: f32,
+        embedding_signature: [u8; music_dht::similarity::SIMILARITY_SIGNATURE_BYTES],
+    },
+    Federated {
+        track: crate::federation::FedTrack,
+        score: f32,
+        embedding_signature: Option<[u8; music_dht::similarity::SIMILARITY_SIGNATURE_BYTES]>,
+    },
+}
+
+impl SimilaritySearchHit {
+    pub fn score(&self) -> f32 {
+        match self {
+            Self::Local { score, .. } | Self::Federated { score, .. } => *score,
+        }
+    }
+
+    pub fn embedding_signature(
+        &self,
+    ) -> Option<[u8; music_dht::similarity::SIMILARITY_SIGNATURE_BYTES]> {
+        match self {
+            Self::Local {
+                embedding_signature,
+                ..
+            } => Some(*embedding_signature),
+            Self::Federated {
+                embedding_signature,
+                ..
+            } => *embedding_signature,
+        }
+    }
+
+    pub fn track_item(&self) -> TrackItem {
+        match self {
+            Self::Local { track, .. } => track.clone(),
+            Self::Federated { track, .. } => crate::federation::pending_track(track),
+        }
+    }
+
+    pub fn federated_track(&self) -> Option<&crate::federation::FedTrack> {
+        match self {
+            Self::Federated { track, .. } => Some(track),
+            Self::Local { .. } => None,
+        }
+    }
+
+    pub fn primary_artist_key(&self) -> String {
+        match self {
+            Self::Local { track, .. } => track
+                .artists
+                .first()
+                .map(|artist| music_dht::normalize_name(&artist.name))
+                .unwrap_or_default(),
+            Self::Federated { track, .. } => track
+                .artist_names
+                .first()
+                .map(|artist| music_dht::normalize_name(artist))
+                .unwrap_or_default(),
+        }
+    }
+
+    pub fn content_key(&self) -> String {
+        match self {
+            Self::Local { track, .. } => track
+                .content_id
+                .clone()
+                .unwrap_or_else(|| format!("local:{}", track.id)),
+            Self::Federated { track, .. } => track
+                .content_id
+                .clone()
+                .unwrap_or_else(|| format!("remote:{}:{}", track.owner, track.item_id)),
+        }
+    }
+}
+
 #[derive(Debug, Default)]
 pub struct SearchState {
     pub query: String,
@@ -1226,6 +1321,59 @@ pub struct SearchState {
     /// Present only for a track-seeded search; text-search refreshes must not
     /// replace this page with a title query.
     pub similarity_source: Option<i64>,
+    /// The source is pinned at row zero; candidates below it are globally
+    /// ranked across the local library and federation.
+    pub similarity_source_track: Option<TrackItem>,
+    pub similarity_tracks: Vec<SimilaritySearchHit>,
+    pub similarity_stats: Option<crate::federation::SimilaritySearchStats>,
+    pub similarity_error: Option<String>,
+}
+
+impl SearchState {
+    pub fn similarity_len(&self) -> usize {
+        usize::from(self.similarity_source_track.is_some()) + self.similarity_tracks.len()
+    }
+
+    pub fn similarity_track(&self, index: usize) -> Option<TrackItem> {
+        if index == 0 {
+            return self.similarity_source_track.clone();
+        }
+        self.similarity_tracks
+            .get(index.checked_sub(1)?)
+            .map(SimilaritySearchHit::track_item)
+    }
+
+    pub fn similarity_fed_track(&self, index: usize) -> Option<&crate::federation::FedTrack> {
+        self.similarity_tracks
+            .get(index.checked_sub(1)?)?
+            .federated_track()
+    }
+
+    pub fn similarity_key(&self, index: usize) -> Option<String> {
+        if index == 0 {
+            return self
+                .similarity_source_track
+                .as_ref()
+                .map(|track| format!("source:{}", track.id));
+        }
+        self.similarity_tracks
+            .get(index.checked_sub(1)?)
+            .map(SimilaritySearchHit::content_key)
+    }
+
+    pub fn similarity_index_for_key(&self, key: &str) -> Option<usize> {
+        if self
+            .similarity_source_track
+            .as_ref()
+            .is_some_and(|track| key == format!("source:{}", track.id))
+        {
+            return Some(0);
+        }
+        self.similarity_tracks
+            .iter()
+            .position(|hit| hit.content_key() == key)
+            .map(|index| index + 1)
+    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]

src/app/update.rs

@@ -905,6 +905,9 @@ fn set_track_scope_cursor(state: &mut AppState, scope: &TrackSelectionScope, val
         TrackSelectionScope::Queue => {
             state.queue_tab.cursor = value;
         }
+        TrackSelectionScope::SimilaritySearch => {
+            set_view_cursor(state, value);
+        }
         TrackSelectionScope::FedSearch => {
             let base = state.search.results.as_ref().map_or(0, |r| r.len())
                 + state.search.fed_artists.len();
@@ -952,6 +955,14 @@ fn current_track_list_context(state: &AppState) -> Option<(TrackSelectionScope,
                 _ => None,
             },
             GlobalView::Search { cursor } => {
+                if state.search.similarity_source.is_some() {
+                    let len = state.search.similarity_len();
+                    return (*cursor < len).then_some((
+                        TrackSelectionScope::SimilaritySearch,
+                        *cursor,
+                        len,
+                    ));
+                }
                 // Only the federated tracks section is selectable here.
                 let base = state.search.results.as_ref().map_or(0, |r| r.len())
                     + state.search.fed_artists.len();
@@ -1044,6 +1055,20 @@ fn current_track_list(state: &AppState) -> Option<(TrackSelectionScope, usize, V
 }
 
 pub fn selected_tracks(state: &AppState) -> Vec<TrackItem> {
+    if state.active_tab == Tab::Global
+        && state.search.similarity_source.is_some()
+        && let Some(GlobalView::Search { cursor }) = state.global.stack.last()
+    {
+        let len = state.search.similarity_len();
+        let indices = state
+            .track_selection
+            .indices(&TrackSelectionScope::SimilaritySearch, len)
+            .unwrap_or_else(|| vec![(*cursor).min(len.saturating_sub(1))]);
+        return indices
+            .into_iter()
+            .filter_map(|index| state.search.similarity_track(index))
+            .collect();
+    }
     // Federated contexts produce queueable placeholders that behave like
     // regular tracks (queue, info, playback-on-demand).
     {
@@ -1276,6 +1301,9 @@ pub fn selected_track(state: &AppState) -> Option<TrackItem> {
                 _ => None,
             },
             GlobalView::Search { cursor } => {
+                if state.search.similarity_source.is_some() {
+                    return state.search.similarity_track(*cursor);
+                }
                 let results = state.search.results.as_ref()?;
                 let offset = cursor.checked_sub(results.artists.len() + results.releases.len())?;
                 match results.tracks.get(offset) {
@@ -1877,10 +1905,13 @@ fn move_selection(state: &mut AppState, dx: isize, dy: isize) {
             refresh_track_selection_cursor(state);
         }
         Some(GlobalView::Search { cursor }) => {
-            // Local results plus the federated section below them.
+            let total = if state.search.similarity_source.is_some() {
-            let total = (state.search.results.as_ref().map_or(0, |r| r.len())
+                state.search.similarity_len()
-                + state.search.fed_artists.len()
+            } else {
-                + state.search.fed_tracks.len()) as isize;
+                state.search.results.as_ref().map_or(0, |r| r.len())
+                    + state.search.fed_artists.len()
+                    + state.search.fed_tracks.len()
+            } as isize;
             if total == 0 {
                 return;
             }
@@ -2000,9 +2031,13 @@ fn current_view_len(state: &AppState) -> usize {
             _ => 0,
         },
         Some(GlobalView::Search { .. }) => {
-            state.search.results.as_ref().map_or(0, |r| r.len())
+            if state.search.similarity_source.is_some() {
-                + state.search.fed_artists.len()
+                state.search.similarity_len()
-                + state.search.fed_tracks.len()
+            } else {
+                state.search.results.as_ref().map_or(0, |r| r.len())
+                    + state.search.fed_artists.len()
+                    + state.search.fed_tracks.len()
+            }
         }
         Some(GlobalView::FedArtist { .. }) => fed_card_len(state),
         Some(GlobalView::FedRelease { index, .. }) => fed_card_release(state, *index)
@@ -2292,31 +2327,47 @@ fn select_current(state: &mut AppState) -> Option<Effect> {
             },
             _ => Outcome::Nothing,
         },
-        Some(GlobalView::Search { cursor }) => match &state.search.results {
+        Some(GlobalView::Search { cursor }) => {
-            Some(results) => {
+            if state.search.similarity_source.is_some() {
-                let artists = results.artists.len();
+                let tracks = (0..state.search.similarity_len())
-                let releases = results.releases.len();
+                    .filter_map(|index| state.search.similarity_track(index))
-                if cursor < artists {
+                    .collect::<Vec<_>>();
-                    Outcome::Push(GlobalView::Artist {
+                if tracks.is_empty() {
-                        id: results.artists[cursor].id,
+                    Outcome::Nothing
-                        cursor: 0,
-                    })
-                } else if cursor < artists + releases {
-                    Outcome::Push(GlobalView::Release {
-                        id: results.releases[cursor - artists].id,
-                        cursor: 0,
-                    })
-                } else if results.tracks.get(cursor - artists - releases).is_some() {
-                    Outcome::Play {
-                        tracks: results.tracks.clone(),
-                        start: cursor - artists - releases,
-                    }
                 } else {
-                    fed_outcome(state, cursor - artists - releases - results.tracks.len())
+                    Outcome::Play {
+                        start: cursor.min(tracks.len() - 1),
+                        tracks,
+                    }
+                }
+            } else {
+                match &state.search.results {
+                    Some(results) => {
+                        let artists = results.artists.len();
+                        let releases = results.releases.len();
+                        if cursor < artists {
+                            Outcome::Push(GlobalView::Artist {
+                                id: results.artists[cursor].id,
+                                cursor: 0,
+                            })
+                        } else if cursor < artists + releases {
+                            Outcome::Push(GlobalView::Release {
+                                id: results.releases[cursor - artists].id,
+                                cursor: 0,
+                            })
+                        } else if results.tracks.get(cursor - artists - releases).is_some() {
+                            Outcome::Play {
+                                tracks: results.tracks.clone(),
+                                start: cursor - artists - releases,
+                            }
+                        } else {
+                            fed_outcome(state, cursor - artists - releases - results.tracks.len())
+                        }
+                    }
+                    None => fed_outcome(state, cursor),
                 }
             }
-            None => fed_outcome(state, cursor),
+        }
-        },
         Some(GlobalView::FedArtist { cursor }) => match &state.fed_artist_view {
             Some((_, Loadable::Ready(card))) => {
                 let release_indices = fed_artist_visible_release_indices(state, card);
@@ -2492,6 +2543,20 @@ pub(crate) fn selected_fed_tracks(state: &AppState) -> Vec<crate::federation::Fe
     if state.active_tab != Tab::Global {
         return Vec::new();
     }
+    if state.search.similarity_source.is_some()
+        && let Some(GlobalView::Search { cursor }) = state.global.stack.last()
+    {
+        let scope = TrackSelectionScope::SimilaritySearch;
+        let len = state.search.similarity_len();
+        let indices = state
+            .track_selection
+            .indices(&scope, len)
+            .unwrap_or_else(|| vec![(*cursor).min(len.saturating_sub(1))]);
+        return indices
+            .into_iter()
+            .filter_map(|index| state.search.similarity_fed_track(index).cloned())
+            .collect();
+    }
     // An active Shift-V range in a federated scope.
     if let Some(scope) = state.track_selection.scope.clone() {
         match scope {
@@ -2796,6 +2861,25 @@ fn federation_select(state: &mut AppState) -> Option<Effect> {
             });
             None
         }
+        SettingsRow::Similarity(SimilarityRow::MinimumScore) => {
+            state.popup = Some(Popup::FedInput {
+                field: FedInputField::SimilarityMinimumScore,
+                input: crate::app::input::LineEdit::new(format!(
+                    "{:.2}",
+                    state.similarity.settings.minimum_score
+                )),
+            });
+            None
+        }
+        SettingsRow::Similarity(SimilarityRow::MaxTracksPerArtist) => {
+            state.popup = Some(Popup::FedInput {
+                field: FedInputField::SimilarityMaxTracksPerArtist,
+                input: crate::app::input::LineEdit::new(
+                    state.similarity.settings.max_tracks_per_artist.to_string(),
+                ),
+            });
+            None
+        }
         SettingsRow::Similarity(SimilarityRow::Workers) => {
             state.popup = Some(Popup::FedInput {
                 field: FedInputField::SimilarityWorkers,

src/config/settings.rs

@@ -45,7 +45,7 @@ pub struct LibraryFilters {
     pub source_mode: LibrarySourceMode,
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct SimilaritySettings {
     /// Local embedding/search master switch. Network participation follows
     /// federation and additionally requires the explicit privacy consent.
@@ -57,6 +57,14 @@ pub struct SimilaritySettings {
     pub profile: String,
     #[serde(default = "default_similarity_workers")]
     pub workers: usize,
+    /// Requester-side cosine score floor. This is search policy, not part of
+    /// the embedding profile, so changing it never invalidates vectors.
+    #[serde(default = "default_similarity_minimum_score")]
+    pub minimum_score: f32,
+    /// Requester-side diversity cap applied independently to local and
+    /// federated candidates.
+    #[serde(default = "default_similarity_max_tracks_per_artist")]
+    pub max_tracks_per_artist: usize,
     #[serde(default)]
     pub federation_consent: bool,
     /// Exact fingerprint of the last fully usable profile. Keeping this
@@ -73,13 +81,15 @@ impl Default for SimilaritySettings {
             model: default_similarity_model(),
             profile: default_similarity_profile(),
             workers: default_similarity_workers(),
+            minimum_score: default_similarity_minimum_score(),
+            max_tracks_per_artist: default_similarity_max_tracks_per_artist(),
             federation_consent: false,
             active_profile: None,
         }
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct AppSettings {
     #[serde(default = "default_volume")]
     pub volume: u8,
@@ -116,6 +126,11 @@ impl AppSettings {
             self.similarity.profile = default_similarity_profile();
         }
         self.similarity.workers = self.similarity.workers.clamp(1, 16);
+        if !self.similarity.minimum_score.is_finite() {
+            self.similarity.minimum_score = default_similarity_minimum_score();
+        }
+        self.similarity.minimum_score = self.similarity.minimum_score.clamp(0.0, 1.0);
+        self.similarity.max_tracks_per_artist = self.similarity.max_tracks_per_artist.clamp(1, 50);
         self
     }
 }
@@ -138,6 +153,14 @@ fn default_similarity_workers() -> usize {
         .unwrap_or(1)
 }
 
+fn default_similarity_minimum_score() -> f32 {
+    0.70
+}
+
+fn default_similarity_max_tracks_per_artist() -> usize {
+    5
+}
+
 /// The historical permanent-download location, kept as the default for
 /// backward compatibility with existing installations.
 pub fn default_music_dir() -> PathBuf {
@@ -204,5 +227,21 @@ hide_featured_only = true
         assert!(settings.library.hide_featured_only);
         assert_eq!(settings.library.source_mode, LibrarySourceMode::Global);
         assert_eq!(settings.music_dir, default_music_dir());
+        assert_eq!(settings.similarity.minimum_score, 0.70);
+        assert_eq!(settings.similarity.max_tracks_per_artist, 5);
+    }
+
+    #[test]
+    fn similarity_search_policy_is_normalized_without_changing_the_profile() {
+        let mut settings = AppSettings::default();
+        let profile = settings.similarity.profile.clone();
+        settings.similarity.minimum_score = f32::NAN;
+        settings.similarity.max_tracks_per_artist = 0;
+
+        let settings = settings.normalized();
+
+        assert_eq!(settings.similarity.minimum_score, 0.70);
+        assert_eq!(settings.similarity.max_tracks_per_artist, 1);
+        assert_eq!(settings.similarity.profile, profile);
     }
 }

src/federation/mod.rs

@@ -338,6 +338,27 @@ pub struct FedSearchResults {
     pub tracks: Vec<FedTrack>,
 }
 
+#[derive(Debug, Clone)]
+pub struct ScoredFedTrack {
+    pub track: FedTrack,
+    pub score: f32,
+    pub embedding_signature: Option<[u8; music_dht::similarity::SIMILARITY_SIGNATURE_BYTES]>,
+}
+
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+pub struct SimilaritySearchStats {
+    pub tracks: usize,
+    pub artists: usize,
+    pub peers_queried: usize,
+    pub elapsed_ms: u64,
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct FedSimilaritySearchResults {
+    pub tracks: Vec<ScoredFedTrack>,
+    pub stats: SimilaritySearchStats,
+}
+
 /// A track found through federated search.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct FedTrack {
@@ -1213,17 +1234,19 @@ impl Federation {
         &self,
         query: crate::similarity::QueryVector,
         limit: usize,
-    ) -> Result<FedSearchResults> {
+    ) -> Result<FedSimilaritySearchResults> {
         anyhow::ensure!(
             self.similarity.network_allowed(),
             "similarity federation has no consent"
         );
         let (service, similarity_dht) = self.similarity_services().await?;
+        let settings = self.similarity.settings();
         similarity::search(
             service,
             similarity_dht,
             query,
             limit,
+            settings.minimum_score,
             Arc::clone(&self.transport_stats),
         )
         .await

src/federation/similarity.rs

@@ -4,9 +4,9 @@
 //! module owns application policy: consent, peer fan-out, local index access,
 //! result conversion, deduplication, and ranking limits.
 
-use std::collections::{HashMap, HashSet};
+use std::collections::HashSet;
 use std::sync::Arc;
-use std::time::Duration;
+use std::time::{Duration, Instant};
 
 use anyhow::{Context as _, Result};
 use futures_util::stream::{self, StreamExt as _};
@@ -16,7 +16,9 @@ use music_dht::{
     ByteStream, EndpointId, ItemId, ItemKind, MusicDhtService, PeerTicket, StreamAcceptor,
 };
 
-use crate::federation::{FedSearchResults, FedTrack, TransportStats};
+use crate::federation::{
+    FedSimilaritySearchResults, FedTrack, ScoredFedTrack, SimilaritySearchStats, TransportStats,
+};
 use crate::similarity::{Manager, QueryVector};
 
 pub use music_dht::similarity::SIMILARITY_ALPN;
@@ -26,7 +28,6 @@ const MAX_QUERY_PEERS: usize = 48;
 const QUERY_CONCURRENCY: usize = 8;
 const QUERY_TIMEOUT: Duration = Duration::from_secs(5);
 const ROUTING_TIMEOUT: Duration = Duration::from_secs(5);
-const MAX_PER_ARTIST: usize = 3;
 const MAX_NEAR_DUPLICATE_SIGNATURE_DISTANCE: u32 = 8;
 
 pub async fn serve_peers(
@@ -62,7 +63,7 @@ async fn serve_one(
         let vector = request.vector;
         let limit = request.limit;
         let matches = tokio::task::spawn_blocking(move || {
-            similarity.search_vector(&profile, &vector, None, None, limit)
+            similarity.search_vector_for_peer(&profile, &vector, limit)
         })
         .await
         .context("local similarity task failed")
@@ -130,8 +131,10 @@ pub async fn search(
     routing: Arc<SimilarityDht>,
     query: QueryVector,
     limit: usize,
+    minimum_score: f32,
     transport: Arc<TransportStats>,
-) -> Result<FedSearchResults> {
+) -> Result<FedSimilaritySearchResults> {
+    let started = Instant::now();
     let own = service.endpoint_id();
     let routed = match tokio::time::timeout(
         ROUTING_TIMEOUT,
@@ -192,6 +195,7 @@ pub async fn search(
     )
     .await;
     let mut successful = 0usize;
+    let mut peers_queried = initial;
     for response in responses {
         match response {
             Ok(peer_hits) => {
@@ -202,6 +206,7 @@ pub async fn search(
         }
     }
     if initial < peers.len() && (hits.len() < limit || successful < initial.min(4)) {
+        peers_queried = peers.len();
         for response in query_peers(
             Arc::clone(&service),
             &peers[initial..],
@@ -219,9 +224,11 @@ pub async fn search(
     hits.sort_by(|left, right| right.1.total_cmp(&left.1));
     let mut dedup = HashSet::new();
     let mut embedding_signatures = vec![query_signature];
-    let mut artist_counts: HashMap<String, usize> = HashMap::new();
     let mut tracks = Vec::new();
-    for (track, _, embedding_signature) in hits {
+    for (track, score, embedding_signature) in hits {
+        if score < minimum_score {
+            break;
+        }
         if query
             .source_content_id
             .as_deref()
@@ -244,26 +251,33 @@ pub async fn search(
         }) {
             continue;
         }
-        let artist = track
-            .artist_names
-            .first()
-            .map(|name| music_dht::normalize_name(name))
-            .unwrap_or_default();
-        let count = artist_counts.entry(artist.clone()).or_default();
-        if !artist.is_empty() && *count >= MAX_PER_ARTIST {
-            continue;
-        }
-        *count += 1;
         if let Some(signature) = embedding_signature {
             embedding_signatures.push(signature);
         }
-        tracks.push(track);
+        tracks.push(ScoredFedTrack {
+            track,
+            score,
+            embedding_signature,
+        });
         if tracks.len() >= limit.min(wire::MAX_SIMILARITY_RESULTS) {
             break;
         }
     }
-    Ok(FedSearchResults {
+    let artists = tracks
-        artists: Vec::new(),
+        .iter()
+        .filter_map(|hit| hit.track.artist_names.first())
+        .map(|name| music_dht::normalize_name(name))
+        .filter(|name| !name.is_empty())
+        .collect::<HashSet<_>>()
+        .len();
+    let elapsed_ms = started.elapsed().as_millis().min(u128::from(u64::MAX)) as u64;
+    Ok(FedSimilaritySearchResults {
+        stats: SimilaritySearchStats {
+            tracks: tracks.len(),
+            artists,
+            peers_queried,
+            elapsed_ms,
+        },
         tracks,
     })
 }

src/similarity.rs

@@ -36,7 +36,7 @@ const EMBEDDING_DIMENSIONS: usize = 1280;
 const MODEL_BATCH: usize = 8;
 const MAX_MODEL_BYTES: usize = 64 * 1024 * 1024;
 const RESULT_LIMIT: usize = 50;
-const MAX_PER_ARTIST: usize = 3;
+const PEER_CANDIDATE_MAX_PER_ARTIST: usize = 10;
 const NEAR_DUPLICATE_COSINE: f32 = 0.995;
 const FULL_TRACK_MAX_SECONDS: u32 = 5 * 60;
 const LONG_TRACK_WINDOW_SECONDS: u32 = 60;
@@ -368,6 +368,52 @@ impl Manager {
         exclude_track_id: Option<i64>,
         exclude_content_id: Option<&str>,
         limit: usize,
+    ) -> Result<Vec<SimilarTrack>> {
+        let settings = lock(&self.settings);
+        let minimum_score = settings.minimum_score;
+        let max_tracks_per_artist = settings.max_tracks_per_artist;
+        drop(settings);
+        self.search_vector_with_policy(
+            profile_id,
+            vector,
+            exclude_track_id,
+            exclude_content_id,
+            limit,
+            minimum_score,
+            max_tracks_per_artist,
+        )
+    }
+
+    /// Returns a wider, policy-neutral candidate set to a remote requester.
+    /// The requester applies its own score threshold and artist diversity
+    /// limit; neither value is part of embedding compatibility.
+    pub(crate) fn search_vector_for_peer(
+        &self,
+        profile_id: &str,
+        vector: &[f32],
+        limit: usize,
+    ) -> Result<Vec<SimilarTrack>> {
+        self.search_vector_with_policy(
+            profile_id,
+            vector,
+            None,
+            None,
+            limit,
+            -1.0,
+            PEER_CANDIDATE_MAX_PER_ARTIST,
+        )
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    fn search_vector_with_policy(
+        &self,
+        profile_id: &str,
+        vector: &[f32],
+        exclude_track_id: Option<i64>,
+        exclude_content_id: Option<&str>,
+        limit: usize,
+        minimum_score: f32,
+        max_tracks_per_artist: usize,
     ) -> Result<Vec<SimilarTrack>> {
         anyhow::ensure!(
             !vector.is_empty() && vector.len() <= 4096,
@@ -396,7 +442,7 @@ impl Manager {
                     entry.vector.as_slice(),
                 )
             })
-            .filter(|(_, score, _, _)| score.is_finite())
+            .filter(|(_, score, _, _)| score.is_finite() && *score >= minimum_score)
             .collect();
         scores.sort_by(|left, right| right.1.total_cmp(&left.1));
 
@@ -410,7 +456,7 @@ impl Manager {
                 continue;
             }
             let count = artist_counts.entry(artist.to_string()).or_default();
-            if !artist.is_empty() && *count >= MAX_PER_ARTIST {
+            if !artist.is_empty() && *count >= max_tracks_per_artist {
                 continue;
             }
             *count += 1;

src/ui/federation.rs

@@ -103,6 +103,14 @@ fn draw_settings_rows(frame: &mut Frame, area: Rect, state: &AppState) {
                 "Preprocessing profile",
                 format!("{} (enter for details)", similarity.profile),
             ),
+            SimilarityRow::MinimumScore => (
+                "Minimum similarity",
+                format!("{:.2}", similarity.minimum_score),
+            ),
+            SimilarityRow::MaxTracksPerArtist => (
+                "Tracks per artist",
+                similarity.max_tracks_per_artist.to_string(),
+            ),
             SimilarityRow::Workers => ("Background workers", similarity.workers.to_string()),
             SimilarityRow::Clear => ("Clear all stored embeddings", "↵".to_string()),
         };

src/ui/global.rs

@@ -900,6 +900,9 @@ fn draw_search(frame: &mut Frame, area: Rect, state: &AppState, cursor: usize) {
         title.push_str("· searching… ");
     }
     let inner = bordered(frame, area, state, title);
+    if search.similarity_source.is_some() {
+        return draw_similarity_search(frame, inner, state, cursor);
+    }
 
     let empty_results = SearchResults::default();
     let results = match &search.results {
@@ -1102,6 +1105,156 @@ fn draw_search(frame: &mut Frame, area: Rect, state: &AppState, cursor: usize) {
     }
 }
 
+fn draw_similarity_search(frame: &mut Frame, area: Rect, state: &AppState, cursor: usize) {
+    let search = &state.search;
+    let status = if search.fed_loading {
+        super::loading_line(state, "searching federation…")
+    } else if let Some(stats) = &search.similarity_stats {
+        let elapsed = if stats.elapsed_ms < 1_000 {
+            format!("{} ms", stats.elapsed_ms)
+        } else {
+            format!("{:.2} s", stats.elapsed_ms as f64 / 1_000.0)
+        };
+        Line::from(vec![
+            Span::styled("Federation · ", theme::accent_for(state)),
+            Span::styled(
+                format!(
+                    "{} tracks · {} artists · {} peers queried · {elapsed}",
+                    stats.tracks, stats.artists, stats.peers_queried
+                ),
+                theme::dim(),
+            ),
+        ])
+    } else if search.similarity_error.is_some() {
+        Line::styled(
+            "Federation search failed · showing local results",
+            error_style(),
+        )
+    } else if search.loading {
+        super::loading_line(state, "preparing local similarity search…")
+    } else {
+        Line::styled("Federation disabled · showing local results", theme::dim())
+    };
+    let [status_area, content] =
+        Layout::vertical([Constraint::Length(1), Constraint::Min(0)]).areas(area);
+    frame.render_widget(Paragraph::new(status), status_area);
+
+    let mut rows: Vec<(Line, Option<String>, Option<usize>)> = Vec::new();
+    rows.push((Line::styled("Tracks", theme::header_for(state)), None, None));
+    if let Some(track) = &search.similarity_source_track {
+        let heart = if state.track_liked(track) {
+            Span::styled("♥ ", theme::accent_for(state))
+        } else {
+            Span::raw("  ")
+        };
+        rows.push((
+            Line::from(vec![
+                heart,
+                Span::raw(track.title.clone()),
+                Span::styled(
+                    format!("  {} · {}", track.artist_line(), track.release_title),
+                    theme::dim(),
+                ),
+            ]),
+            Some(super::track_meta_suffix(track, true)),
+            Some(0),
+        ));
+    }
+    for (offset, hit) in search.similarity_tracks.iter().enumerate() {
+        let index = offset + 1;
+        match hit {
+            crate::app::state::SimilaritySearchHit::Local { track, .. } => {
+                let heart = if state.track_liked(track) {
+                    Span::styled("♥ ", theme::accent_for(state))
+                } else {
+                    Span::raw("  ")
+                };
+                rows.push((
+                    Line::from(vec![
+                        heart,
+                        Span::raw(track.title.clone()),
+                        Span::styled(
+                            format!("  {} · {}", track.artist_line(), track.release_title),
+                            theme::dim(),
+                        ),
+                    ]),
+                    Some(super::track_meta_suffix(track, true)),
+                    Some(index),
+                ));
+            }
+            crate::app::state::SimilaritySearchHit::Federated { track, .. } => {
+                let heart = if state.fed_track_liked(track) {
+                    Span::styled("♥ ", theme::accent_for(state))
+                } else {
+                    Span::raw("  ")
+                };
+                let origin = if track.own {
+                    "your library".to_string()
+                } else {
+                    format!("peer {}…", track.owner_short())
+                };
+                let mut meta = track.duration_label();
+                if let Some(year) = track.year {
+                    if !meta.is_empty() {
+                        meta.push_str(" · ");
+                    }
+                    meta.push_str(&year.to_string());
+                }
+                rows.push((
+                    Line::from(vec![
+                        heart,
+                        fed_track_availability_prefix(state, track),
+                        Span::raw(track.title.clone()),
+                        Span::styled(
+                            format!("  {} · {origin}", track.artist_line()),
+                            theme::dim(),
+                        ),
+                    ]),
+                    Some(meta),
+                    Some(index),
+                ));
+            }
+        }
+    }
+
+    let scope = crate::app::state::TrackSelectionScope::SimilaritySearch;
+    let mut selected = std::collections::HashSet::new();
+    if state.track_selection.is_active_for(&scope)
+        && let Some(indices) = state
+            .track_selection
+            .indices(&scope, search.similarity_len())
+    {
+        selected.extend(indices);
+    }
+    let cursor_row = rows
+        .iter()
+        .position(|(_, _, row_cursor)| *row_cursor == Some(cursor))
+        .unwrap_or(0);
+    let visible = usize::from(content.height.max(1));
+    let first = cursor_row
+        .saturating_sub(visible / 2)
+        .min(rows.len().saturating_sub(visible));
+    for (offset, (line, right, row_cursor)) in
+        rows.into_iter().enumerate().skip(first).take(visible)
+    {
+        let rect = Rect {
+            x: content.x,
+            y: content.y + (offset - first) as u16,
+            width: content.width,
+            height: 1,
+        };
+        if let Some(row_index) = row_cursor
+            && selected.contains(&row_index)
+            && row_index != cursor
+        {
+            frame
+                .buffer_mut()
+                .set_style(rect, theme::selection_for(state));
+        }
+        draw_row(frame, rect, state, line, right, row_cursor == Some(cursor));
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Federated artist card (assembled from peer catalogs)
 // ---------------------------------------------------------------------------