Expose exact music filters in desktop and local agent clients

apps/desktop/src-tauri/src/main.rs

@@ -228,6 +228,8 @@ struct Filters {
     code_only: bool,
     folder: Option<PathBuf>,
     extension: Option<String>,
+    media_artist: Option<String>,
+    media_title: Option<String>,
     min_size: Option<u64>,
     max_size: Option<u64>,
     min_duration_ms: Option<u32>,
@@ -242,6 +244,8 @@ impl From<Filters> for SearchOptions {
             code_only: value.code_only,
             folder: value.folder,
             extension: value.extension,
+            media_artist: value.media_artist,
+            media_title: value.media_title,
             min_size: value.min_size,
             max_size: value.max_size,
             min_duration_ms: value.min_duration_ms,
@@ -253,18 +257,36 @@ impl From<Filters> for SearchOptions {
 }
 
 // Each job owns its connection. Slow indexing never holds a desktop mutex.
+fn validate_search_input(query: &str, options: &SearchOptions) -> Result<(), String> {
+    if query.trim().is_empty() && options.media_artist.is_none() && options.media_title.is_none() {
+        return Err("Supply search text or an exact media artist/title constraint".to_owned());
+    }
+    for value in [
+        options.media_artist.as_deref(),
+        options.media_title.as_deref(),
+    ]
+    .into_iter()
+    .flatten()
+    {
+        searchi_core::normalize_media_field(value).map_err(|error| error.to_string())?;
+    }
+    Ok(())
+}
+
 #[tauri::command]
 async fn search(
     query: String,
     filters: Option<Filters>,
     state: State<'_, AppState>,
 ) -> Result<Vec<SearchResult>, String> {
+    let options: SearchOptions = filters.unwrap_or_default().into();
+    validate_search_input(&query, &options)?;
     let lexical = state.lexical.clone();
     tauri::async_runtime::spawn_blocking(move || {
         lexical
             .try_lock()
             .map_err(|_| "Keyword worker is busy; try the latest query again.".to_owned())?
-            .search_with_options(&query, 50, &filters.unwrap_or_default().into())
+            .search_with_options(&query, 50, &options)
             .map_err(|e| e.to_string())
     })
     .await
@@ -290,19 +312,15 @@ async fn search_measured(
     tauri::async_runtime::spawn_blocking(move || {
         trace.end(queue, Default::default());
         let result = (|| {
+            let options: SearchOptions = filters.unwrap_or_default().into();
+            validate_search_input(&query, &options)?;
             let index = trace.timed("desktop.lexical_lock", None, |_, _| {
                 lexical
                     .try_lock()
                     .map_err(|_| "Keyword worker is busy; try the latest query again.".to_owned())
             })?;
             index
-                .search_with_options_traced(
+                .search_with_options_traced(&query, 50, &options, &mut trace, None)
-                    &query,
-                    50,
-                    &filters.unwrap_or_default().into(),
-                    &mut trace,
-                    None,
-                )
                 .map_err(|error| error.to_string())
         })();
         measured_outcome(result, trace)
@@ -841,4 +859,42 @@ mod tests {
                 < preview_pixel_limit(Some(image::ImageFormat::Jpeg))
         );
     }
+    #[test]
+    fn native_exact_media_filters_preserve_fields_and_validate_empty_queries() {
+        let dir = tempfile::tempdir().unwrap();
+        let file = dir.path().join("track.ogg");
+        std::fs::write(&file, b"metadata storage fixture").unwrap();
+        let mut index = SearchIndex::open(":memory:").unwrap();
+        index.index_folder(dir.path()).unwrap();
+        let path = file.canonicalize().unwrap().to_string_lossy().into_owned();
+        let (bytes, modified) = index.file_signature(&path).unwrap().unwrap();
+        let revision = index.media_change_revision(&path, bytes, modified).unwrap();
+        let tags = std::collections::BTreeMap::from([
+            ("artist".to_owned(), "Björk".to_owned()),
+            ("title".to_owned(), "Jóga".to_owned()),
+            ("comment".to_owned(), "artist: Other Artist".to_owned()),
+        ]);
+        index
+            .set_structured_media_metadata_at_revision(
+                &path, &tags, 1000, bytes, modified, revision,
+            )
+            .unwrap();
+        let filters: Filters =
+            serde_json::from_str(r#"{"media_artist":" BJÖRK ","media_title":"JÓGA"}"#).unwrap();
+        let mut options: SearchOptions = filters.into();
+        assert!(validate_search_input("", &options).is_ok());
+        assert_eq!(
+            index.search_with_options("", 1, &options).unwrap()[0].filename,
+            "track.ogg"
+        );
+        options.media_artist = Some("Other Artist".into());
+        assert!(index
+            .search_with_options("", 1, &options)
+            .unwrap()
+            .is_empty());
+        options.media_artist = Some(" ".into());
+        assert!(validate_search_input("", &options).is_err());
+        assert!(validate_search_input("", &SearchOptions::default()).is_err());
+        assert!(validate_search_input("song", &SearchOptions::default()).is_ok());
+    }
 }

apps/desktop/src/main.ts

@@ -15,6 +15,7 @@ import {
   LatestLane,
   semanticAvailable,
   scopedFilters,
+  hasSearchInput,
   SEMANTIC_SETTLE_MS,
 } from "./search-state";
 import type { SemanticPhase, SearchFilters } from "./search-state";
@@ -146,7 +147,7 @@ interface SearchRequest {
 }
 
 document.querySelector<HTMLDivElement>("#app")!.innerHTML = `
-<header><div class="brand"><img class="brand-symbol" src="/searchi-symbol.png" alt=""><span class="wordmark">searchi</span></div><span id="index-status" class="index-status">Loading your index…</span><div class="header-actions"><button id="add-folder" class="quiet-button" type="button">${icon("folderAdd")}<span>Add folder</span></button><details id="filters" class="popover"><summary>${icon("filter")}<span id="scope-label">All files</span>${icon("chevron")}</summary><div class="popover-panel"><h2>Filter your search</h2><div class="filters-grid"><label>Search scope<select id="filter-scope"><option value="all">All files</option><option value="code">Code</option></select></label><label>Within folder<input id="filter-folder" placeholder="Absolute folder path"></label><label>Extension<input id="filter-extension" placeholder="pdf, md, txt…"></label><label>Minimum size (bytes)<input id="filter-min" type="number" min="0" step="1"></label><label>Maximum size (bytes)<input id="filter-max" type="number" min="0" step="1"></label><label>Minimum duration (seconds)<input id="filter-duration-min" type="number" min="0" step="0.1"></label><label>Maximum duration (seconds)<input id="filter-duration-max" type="number" min="0" step="0.1"></label><label>Modified from<input id="filter-after" type="date"></label><label>Modified through<input id="filter-before" type="date"></label></div></div></details><details id="settings" class="popover"><summary class="icon-button" aria-label="Settings" title="Settings">${icon("settings")}</summary><div class="popover-panel"><h2>Settings</h2><section class="appearance-settings" aria-labelledby="appearance-heading"><h3 id="appearance-heading">Appearance</h3><label for="background-material">Window background</label><select id="background-material"><option value="solid">Solid</option><option value="glass">Glass</option><option value="frosted">Frosted glass</option></select><div class="appearance-opacity"><label for="background-opacity">Background tint</label><output id="background-opacity-value" for="background-opacity">90%</output></div><input id="background-opacity" type="range" min="70" max="100" step="1" value="90" aria-describedby="appearance-status"><p id="appearance-status" class="hint" role="status">A subtle window background. Search results and passages stay clear.</p></section><h3>Folders & resources</h3><p id="shortcut-status" class="hint"></p><label class="resource-label" for="cpu-threads">CPU thread budget</label><select id="cpu-threads">${Array.from({ length: 8 }, (_, i) => `<option value="${i + 1}">${i + 1} ${i === 1 ? "threads (default)" : i ? "threads" : "thread (low power)"}</option>`).join("")}</select><p class="hint">Search automatically uses supported acceleration with CPU fallback. Two or more threads let search run alongside indexing; one thread can delay semantic search during indexing.</p><ul id="roots" aria-label="Selected folders"></ul><label class="performance-toggle"><input id="performance-toggle" type="checkbox">Performance details</label><p class="hint">Local timing diagnostics for new searches. Queries and file paths are excluded from copied reports.</p><details id="ai-settings" class="ai-settings"><summary>Optional AI answers</summary><label class="performance-toggle"><input id="ai-enabled" type="checkbox">Enable summaries and questions</label><p class="hint">Disabled by default. Only an explicit action sends the shown passage to your configured endpoint.</p><label>OpenAI-compatible base URL<input id="ai-endpoint" type="url" placeholder="http://localhost:1234/v1" autocomplete="off" maxlength="2048"></label><label>Model<input id="ai-model" placeholder="Your model name" autocomplete="off" maxlength="200"></label><label>API key (optional, this session only)<input id="ai-key" type="password" autocomplete="off" maxlength="2048"></label><button id="ai-clear-key" type="button">Clear key</button><p class="hint">Endpoint, model and key stay in this app session. The key authenticates requests to your endpoint.</p></details></div></details></div></header>
+<header><div class="brand"><img class="brand-symbol" src="/searchi-symbol.png" alt=""><span class="wordmark">searchi</span></div><span id="index-status" class="index-status">Loading your index…</span><div class="header-actions"><button id="add-folder" class="quiet-button" type="button">${icon("folderAdd")}<span>Add folder</span></button><details id="filters" class="popover"><summary>${icon("filter")}<span id="scope-label">All files</span>${icon("chevron")}</summary><div class="popover-panel"><h2>Filter your search</h2><div class="filters-grid"><label>Search scope<select id="filter-scope"><option value="all">All files</option><option value="code">Code</option></select></label><label>Within folder<input id="filter-folder" placeholder="Absolute folder path"></label><label>Extension<input id="filter-extension" placeholder="pdf, md, txt…"></label><label>Artist (exact)<input id="filter-artist" placeholder="Artist from music tags" maxlength="256"></label><label>Track title (exact)<input id="filter-title" placeholder="Title from music tags" maxlength="256"></label><label>Minimum size (bytes)<input id="filter-min" type="number" min="0" step="1"></label><label>Maximum size (bytes)<input id="filter-max" type="number" min="0" step="1"></label><label>Minimum duration (seconds)<input id="filter-duration-min" type="number" min="0" step="0.1"></label><label>Maximum duration (seconds)<input id="filter-duration-max" type="number" min="0" step="0.1"></label><label>Modified from<input id="filter-after" type="date"></label><label>Modified through<input id="filter-before" type="date"></label></div></div></details><details id="settings" class="popover"><summary class="icon-button" aria-label="Settings" title="Settings">${icon("settings")}</summary><div class="popover-panel"><h2>Settings</h2><section class="appearance-settings" aria-labelledby="appearance-heading"><h3 id="appearance-heading">Appearance</h3><label for="background-material">Window background</label><select id="background-material"><option value="solid">Solid</option><option value="glass">Glass</option><option value="frosted">Frosted glass</option></select><div class="appearance-opacity"><label for="background-opacity">Background tint</label><output id="background-opacity-value" for="background-opacity">90%</output></div><input id="background-opacity" type="range" min="70" max="100" step="1" value="90" aria-describedby="appearance-status"><p id="appearance-status" class="hint" role="status">A subtle window background. Search results and passages stay clear.</p></section><h3>Folders & resources</h3><p id="shortcut-status" class="hint"></p><label class="resource-label" for="cpu-threads">CPU thread budget</label><select id="cpu-threads">${Array.from({ length: 8 }, (_, i) => `<option value="${i + 1}">${i + 1} ${i === 1 ? "threads (default)" : i ? "threads" : "thread (low power)"}</option>`).join("")}</select><p class="hint">Search automatically uses supported acceleration with CPU fallback. Two or more threads let search run alongside indexing; one thread can delay semantic search during indexing.</p><ul id="roots" aria-label="Selected folders"></ul><label class="performance-toggle"><input id="performance-toggle" type="checkbox">Performance details</label><p class="hint">Local timing diagnostics for new searches. Queries and file paths are excluded from copied reports.</p><details id="ai-settings" class="ai-settings"><summary>Optional AI answers</summary><label class="performance-toggle"><input id="ai-enabled" type="checkbox">Enable summaries and questions</label><p class="hint">Disabled by default. Only an explicit action sends the shown passage to your configured endpoint.</p><label>OpenAI-compatible base URL<input id="ai-endpoint" type="url" placeholder="http://localhost:1234/v1" autocomplete="off" maxlength="2048"></label><label>Model<input id="ai-model" placeholder="Your model name" autocomplete="off" maxlength="200"></label><label>API key (optional, this session only)<input id="ai-key" type="password" autocomplete="off" maxlength="2048"></label><button id="ai-clear-key" type="button">Clear key</button><p class="hint">Endpoint, model and key stay in this app session. The key authenticates requests to your endpoint.</p></details></div></details></div></header>
 <main>
 <form id="search-form" role="search"><label class="sr-only" for="query">Search your files</label>${icon("search")}<input id="query" type="search" placeholder="Search a filename, phrase, or what you remember…" autocomplete="off" spellcheck="false" maxlength="1000"><kbd id="focus-shortcut">Ctrl K</kbd><button id="clear-query" class="icon-button" type="button" aria-label="Clear search" title="Clear search">${icon("dismiss")}</button></form>
 <details id="semantic-panel"><summary>${icon("sparkles")}<span id="semantic-status" role="status" aria-live="polite">Preparing local semantic search…</span><span id="semantic-device" class="kind">Local model</span>${icon("chevron")}</summary><div class="semantic-content"><strong>Google EmbeddingGemma 2</strong><progress id="semantic-progress" aria-label="Local model setup progress"></progress><p id="semantic-detail" class="hint">The verified local model downloads automatically on first launch (865 MB). Your files stay on this device.</p><div class="semantic-actions"><button id="retry-model" type="button" hidden>Retry model setup</button><button id="rebuild-semantic" type="button" hidden>Rebuild semantic index</button></div></div></details>
@@ -305,6 +306,13 @@ const automaticIndex = new AutomaticIndexGate();
 
 function refreshEmptySearchState() {
   if (!latestSearch || latestSearch.id !== requestId || results.length) return;
+  if (!latestSearch.query.trim()) {
+    element("empty").querySelector("h2")!.textContent =
+      "No matching music tags.";
+    element("empty").querySelector("p")!.textContent =
+      "Try the complete artist or track title from your files. Missing tags cannot match these filters.";
+    return;
+  }
   let phase: SemanticPhase;
   if (querySemanticFailed || localSemanticError || semanticStatus?.error)
     phase = "unavailable";
@@ -1042,6 +1050,8 @@ function captureFilters() {
   return scopedFilters(element<HTMLSelectElement>("filter-scope").value, {
     folder: input("filter-folder") || null,
     extension: input("filter-extension") || null,
+    media_artist: input("filter-artist") || null,
+    media_title: input("filter-title") || null,
     min_duration_ms: duration("filter-duration-min"),
     max_duration_ms: duration("filter-duration-max"),
     min_size: size("filter-min"),
@@ -1236,7 +1246,7 @@ function refreshIndexedSearch(
   };
   latestSearch = refreshed;
   submitSearch(refreshed, "lexical");
-  if (canSearchSemantically()) {
+  if (refreshed.query.trim() && canSearchSemantically()) {
     hybridTimer = setTimeout(() => {
       if (isCurrent(refreshed)) submitSearch(refreshed, "hybrid");
     }, SEMANTIC_SETTLE_MS);
@@ -1287,23 +1297,23 @@ async function search(inputAt = performance.now()) {
   querySemanticFailed = false;
   shownLane = "lexical";
   const value = query.value.trim();
-  if (!value) {
-    resultSelection.begin("");
-    element("performance-panel").hidden = true;
-    results = [];
-    displayedLiteralQuery = literalQuery("");
-    displayedRequestId = null;
-    selected = -1;
-    render();
-    element("result-summary").textContent = "READY WHEN YOU ARE";
-    element("empty").querySelector("h2")!.textContent =
-      "Find what matters. Locally.";
-    element("empty").querySelector("p")!.textContent =
-      "Index a folder, then search a filename, phrase, or what you remember.";
-    return;
-  }
   try {
     const filters = captureFilters();
+    if (!hasSearchInput(value, filters)) {
+      resultSelection.begin("");
+      element("performance-panel").hidden = true;
+      results = [];
+      displayedLiteralQuery = literalQuery("");
+      displayedRequestId = null;
+      selected = -1;
+      render();
+      element("result-summary").textContent = "READY WHEN YOU ARE";
+      element("empty").querySelector("h2")!.textContent =
+        "Find what matters. Locally.";
+      element("empty").querySelector("p")!.textContent =
+        "Index a folder, then search a filename, phrase, or what you remember.";
+      return;
+    }
     resultSelection.begin(JSON.stringify([value, filters]));
     const request: SearchRequest = {
       id: requestId,
@@ -1322,7 +1332,7 @@ async function search(inputAt = performance.now()) {
     element("result-summary").textContent = "SEARCHING…";
     submitSearch(request, "lexical");
     hybridTimer = setTimeout(() => {
-      if (isCurrent(request) && canSearchSemantically())
+      if (value && isCurrent(request) && canSearchSemantically())
         submitSearch(request, "hybrid");
     }, SEMANTIC_SETTLE_MS);
   } catch (error) {

apps/desktop/src/search-state.ts

@@ -11,6 +11,16 @@ export function scopedFilters(
   return Object.freeze({ ...filters, code_only: scope === "code" });
 }
 
+/** Exact music metadata can be searched without embedding an empty query. */
+export function hasSearchInput(query: string, filters: SearchFilters): boolean {
+  return Boolean(
+    query.trim() ||
+      (typeof filters.media_artist === "string" &&
+        filters.media_artist.trim()) ||
+      (typeof filters.media_title === "string" && filters.media_title.trim()),
+  );
+}
+
 /** Let rapid typing settle before starting the model lane. */
 export const SEMANTIC_SETTLE_MS = 120;
 

apps/desktop/tests/search-state.test.mjs

@@ -1,6 +1,6 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { LatestLane, AutomaticIndexGate, emptySearchState, semanticAvailable, SEMANTIC_SETTLE_MS, scopedFilters } from '../src/search-state.ts';
+import { LatestLane, AutomaticIndexGate, emptySearchState, semanticAvailable, SEMANTIC_SETTLE_MS, hasSearchInput, scopedFilters } from '../src/search-state.ts';
 const settle = () => new Promise(resolve => setImmediate(resolve));
 
 test('coalesces queued keystrokes and discards stale responses', async () => {
@@ -107,3 +107,11 @@ test('same-query scope change discards old lane output and runs latest scoped re
   assert.equal(accepted[0].filters.code_only, true);
   assert.equal(accepted[0].filters.extension, 'rs');
 });
+
+
+test('exact music fields allow metadata-only searches without general filter browsing', () => {
+  assert.equal(hasSearchInput('', scopedFilters('all', {media_artist: ' Artist '})), true);
+  assert.equal(hasSearchInput('', scopedFilters('all', {media_title: 'Song'})), true);
+  assert.equal(hasSearchInput('   ', scopedFilters('all', {media_artist: ' ', extension: 'mp3'})), false);
+  assert.equal(hasSearchInput('violin', scopedFilters('all', {})), true);
+});

crates/searchi-cli/src/main.rs

@@ -52,6 +52,7 @@ enum Command {
         #[arg(long)]
         db: PathBuf,
         /// Search text; quote phrases containing spaces in your shell.
+        #[arg(default_value = "")]
         query: String,
         /// Maximum number of returned results (1–1000).
         #[arg(long, default_value_t = 20, value_parser = clap::value_parser!(u16).range(1..=1000))]
@@ -74,6 +75,12 @@ enum Command {
         /// File extension, with or without the leading dot.
         #[arg(long)]
         extension: Option<String>,
+        /// Exact artist tag; unrelated semantic neighbours cannot bypass it.
+        #[arg(long)]
+        media_artist: Option<String>,
+        /// Exact track/media title tag.
+        #[arg(long)]
+        media_title: Option<String>,
         #[arg(long)]
         min_size: Option<u64>,
         #[arg(long)]
@@ -171,6 +178,8 @@ fn main() -> Result<()> {
             folder,
             code_only,
             extension,
+            media_artist,
+            media_title,
             min_size,
             max_size,
             min_duration_ms,
@@ -181,14 +190,16 @@ fn main() -> Result<()> {
             embedding_worker,
             cpu_threads,
         } => {
-            if query.trim().is_empty() {
+            if query.trim().is_empty() && media_artist.is_none() && media_title.is_none() {
-                bail!("Search text cannot be empty");
+                bail!("Supply search text or an exact media artist/title constraint");
             }
             require_existing_index(&db)?;
             let options = SearchOptions {
                 folder,
                 code_only,
                 extension,
+                media_artist,
+                media_title,
                 min_size,
                 max_size,
                 min_duration_ms,
@@ -201,7 +212,10 @@ fn main() -> Result<()> {
             } else {
                 MetricsMode::Basic
             });
-            let results = if let (Some(model), Some(runtime)) = (model_dir, embedding_worker) {
+            let semantic_assets = model_dir
+                .zip(embedding_worker)
+                .filter(|_| !query.trim().is_empty());
+            let results = if let Some((model, runtime)) = semantic_assets {
                 let mut service = trace.timed("cli.session_initialize", None, |_, _| {
                     HybridSearch::open_query(&db, model, runtime, usize::from(cpu_threads))
                 })?;
@@ -393,4 +407,62 @@ mod tests {
             }
         ));
     }
+    #[test]
+    fn exact_media_cli_filters_match_real_metadata_without_query_or_model() {
+        let dir = tempfile::tempdir().unwrap();
+        let file = dir.path().join("track.ogg");
+        std::fs::write(&file, b"metadata storage fixture").unwrap();
+        let mut index = SearchIndex::open(":memory:").unwrap();
+        index.index_folder(dir.path()).unwrap();
+        let path = file.canonicalize().unwrap().to_string_lossy().into_owned();
+        let (bytes, modified) = index.file_signature(&path).unwrap().unwrap();
+        let revision = index.media_change_revision(&path, bytes, modified).unwrap();
+        let tags = std::collections::BTreeMap::from([
+            ("artist".to_owned(), "Björk".to_owned()),
+            ("title".to_owned(), "Jóga".to_owned()),
+            ("comment".to_owned(), "artist: Other Artist".to_owned()),
+        ]);
+        index
+            .set_structured_media_metadata_at_revision(
+                &path, &tags, 1000, bytes, modified, revision,
+            )
+            .unwrap();
+        let cli = Cli::try_parse_from([
+            "searchi",
+            "search",
+            "--db",
+            "index.db",
+            "--media-artist",
+            " BJÖRK ",
+            "--media-title",
+            "JÓGA",
+        ])
+        .unwrap();
+        let Command::Search {
+            query,
+            media_artist,
+            media_title,
+            ..
+        } = cli.command
+        else {
+            panic!("search command");
+        };
+        assert!(query.is_empty());
+        let mut options = SearchOptions {
+            media_artist,
+            media_title,
+            ..Default::default()
+        };
+        assert_eq!(
+            index.search_with_options(&query, 1, &options).unwrap()[0].filename,
+            "track.ogg"
+        );
+        options.media_artist = Some("Other Artist".into());
+        assert!(index
+            .search_with_options(&query, 1, &options)
+            .unwrap()
+            .is_empty());
+        options.media_artist = Some(" ".into());
+        assert!(index.search_with_options(&query, 1, &options).is_err());
+    }
 }

crates/searchi-cli/src/mcp.rs

@@ -29,7 +29,8 @@ use tokio_util::codec::{FramedRead, FramedWrite};
 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 #[serde(deny_unknown_fields)]
 struct SearchInput {
-    /// Filename, content or remembered meaning. At most 4096 UTF-8 bytes.
+    /// Filename, content or remembered meaning. At most 4096 UTF-8 bytes;
+    /// may be empty when an exact media_artist/media_title constraint is supplied.
     query: String,
 
     /// Maximum returned files, 1–100; default 10.
@@ -43,6 +44,10 @@ struct SearchInput {
     code_only: bool,
 
     extension: Option<String>,
+    /// Exact full artist tag, case-insensitive; at most 1024 UTF-8 bytes.
+    media_artist: Option<String>,
+    /// Exact full media title tag, case-insensitive; at most 1024 UTF-8 bytes.
+    media_title: Option<String>,
 
     min_size: Option<u64>,
 
@@ -132,9 +137,10 @@ impl AgentServer {
 
             ensure!(
 
-                !input.query.trim().is_empty() && input.query.len() <= 4096,
+                input.query.len() <= 4096 && (!input.query.trim().is_empty()
+                    || input.media_artist.is_some() || input.media_title.is_some()),
 
-                "Query must contain 1–4096 UTF-8 bytes"
+                "Supply search text (at most 4096 UTF-8 bytes) or an exact media artist/title constraint"
 
             );
 
@@ -174,6 +180,8 @@ impl AgentServer {
                 code_only: input.code_only,
 
                 extension: input.extension,
+                media_artist: input.media_artist,
+                media_title: input.media_title,
 
                 min_size: input.min_size,
 
@@ -189,7 +197,12 @@ impl AgentServer {
 
             };
 
-            let (mode, response) = if let Some(hybrid) = state.hybrid.as_mut() {
+            let semantic_available = state.hybrid.is_some();
+            let (mode, response) = if input.query.trim().is_empty() {
+                ("metadata_only", state.index.search_with_options_measured(
+                    &input.query, usize::from(input.limit), &options, false,
+                )?)
+            } else if let Some(hybrid) = state.hybrid.as_mut() {
 
                 ("hybrid", hybrid.search_measured(
 
@@ -278,7 +291,7 @@ impl AgentServer {
                 "mode": mode,
                 "code_only": input.code_only,
 
-                "semantic_available": mode == "hybrid",
+                "semantic_available": semantic_available,
 
                 "results": results,
 
@@ -513,3 +526,62 @@ pub fn serve(
         Ok(())
     })
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn metadata_only_mcp_filters_real_fields_and_rejects_empty_constraints() {
+        let dir = tempfile::tempdir().unwrap();
+        let file = dir.path().join("track.ogg");
+        std::fs::write(&file, b"metadata storage fixture").unwrap();
+        let mut index = SearchIndex::open(":memory:").unwrap();
+        index.index_folder(dir.path()).unwrap();
+        let path = file.canonicalize().unwrap().to_string_lossy().into_owned();
+        let (bytes, modified) = index.file_signature(&path).unwrap().unwrap();
+        let revision = index.media_change_revision(&path, bytes, modified).unwrap();
+        let tags = std::collections::BTreeMap::from([
+            ("artist".to_owned(), "Björk".to_owned()),
+            ("title".to_owned(), "Jóga".to_owned()),
+            ("comment".to_owned(), "artist: Other Artist".to_owned()),
+        ]);
+        index
+            .set_structured_media_metadata_at_revision(
+                &path, &tags, 1000, bytes, modified, revision,
+            )
+            .unwrap();
+        let server = AgentServer {
+            state: Arc::new(Mutex::new(State {
+                index,
+                hybrid: None,
+                handles: BTreeMap::new(),
+                recent: VecDeque::new(),
+            })),
+            gate: Arc::new(tokio::sync::Semaphore::new(1)),
+        };
+        let runtime = tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .unwrap();
+        for (input, expected) in [
+            (
+                json!({"query":"", "media_artist":" BJÖRK ", "media_title":"JÓGA"}),
+                Some(1),
+            ),
+            (json!({"query":"", "media_artist":"Other Artist"}), Some(0)),
+            (json!({"query":"", "media_artist":" "}), None),
+            (json!({"query":""}), None),
+        ] {
+            let response =
+                runtime.block_on(server.search(Parameters(serde_json::from_value(input).unwrap())));
+            if let Some(count) = expected {
+                let data = response.structured_content.unwrap();
+                assert_eq!(data["mode"], "metadata_only");
+                assert_eq!(data["semantic_available"], false);
+                assert_eq!(data["results"].as_array().unwrap().len(), count);
+            } else {
+                assert_eq!(response.is_error, Some(true));
+            }
+        }
+    }
+}