feat(server): implement FTS5-based full-text search (#5079)

* build: add sqlite_fts5 build tag to enable FTS5 support

* feat: add SearchBackend config option (default: fts)

* feat: add buildFTS5Query for safe FTS5 query preprocessing

* feat: add FTS5 search backend with config toggle, refactor legacy search

- Add searchExprFunc type and getSearchExpr() for backend selection
- Rename fullTextExpr to legacySearchExpr
- Add ftsSearchExpr using FTS5 MATCH subquery
- Update fullTextFilter in sql_restful.go to use configured backend

* feat: add FTS5 migration with virtual tables, triggers, and search_participants

Creates FTS5 virtual tables for media_file, album, and artist with
unicode61 tokenizer and diacritic folding. Adds search_participants
column, populates from JSON, and sets up INSERT/UPDATE/DELETE triggers.

* feat: populate search_participants in PostMapArgs for FTS5 indexing

* test: add FTS5 search integration tests

* fix: exclude FTS5 virtual tables from e2e DB restore

The restoreDB function iterates all tables in sqlite_master and
runs DELETE + INSERT to reset state. FTS5 contentless virtual tables
cannot be directly deleted from. Since triggers handle FTS5 sync
automatically, simply skip tables matching *_fts and *_fts_* patterns.

* build: add compile-time guard for sqlite_fts5 build tag

Same pattern as netgo: compilation fails with a clear error if
the sqlite_fts5 build tag is missing.

* build: add sqlite_fts5 tag to reflex dev server config

* build: extract GO_BUILD_TAGS variable in Makefile to avoid duplication

* fix: strip leading * from FTS5 queries to prevent "unknown special query" error

* feat: auto-append prefix wildcard to FTS5 search tokens for broader matching

Every plain search token now gets a trailing * appended (e.g., "love" becomes
"love*"), so searching for "love" also matches "lovelace", "lovely", etc.
Quoted phrases are preserved as exact matches without wildcards. Results are
ordered alphabetically by name/title, so shorter exact matches naturally
appear first.

* fix: clarify comments about FTS5 operator neutralization

The comments said "strip" but the code lowercases operators to
neutralize them (FTS5 operators are case-sensitive). Updated comments
to accurately describe the behavior.

* fix: use fmt.Sprintf for FTS5 phrase placeholders

The previous encoding used rune('0'+index) which silently breaks with
10+ quoted phrases. Use fmt.Sprintf for arbitrary index support.

* fix: validate and normalize SearchBackend config option

Normalize the value to lowercase and fall back to "fts" with a log
warning for unrecognized values. This prevents silent misconfiguration
from typos like "FTS", "Legacy", or "fts5".

* refactor: improve documentation for build tags and FTS5 requirements

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor: convert FTS5 query and search backend normalization tests to DescribeTable format

Signed-off-by: Deluan <deluan@navidrome.org>

* fix: add sqlite_fts5 build tag to golangci configuration

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: add UISearchDebounceMs configuration option and update related components

Signed-off-by: Deluan <deluan@navidrome.org>

* fix: fall back to legacy search when SearchFullString is enabled

FTS5 is token-based and cannot match substrings within words, so
getSearchExpr now returns legacySearchExpr when SearchFullString
is true, regardless of SearchBackend setting.

* fix: add sqlite_fts5 build tag to CI pipeline and Dockerfile

* fix: add WHEN clauses to FTS5 AFTER UPDATE triggers

Added WHEN clauses to the media_file_fts_au, album_fts_au, and
artist_fts_au triggers so they only fire when FTS-indexed columns
actually change. Previously, every row update (e.g., play count, rating,
starred status) triggered an unnecessary delete+insert cycle in the FTS
shadow tables. The WHEN clauses use IS NOT for NULL-safe comparison of
each indexed column, avoiding FTS index churn for non-indexed updates.

* feat: add SearchBackend configuration option to data and insights components

Signed-off-by: Deluan <deluan@navidrome.org>

* fix: enhance input sanitization for FTS5 by stripping additional punctuation and special characters

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: add search_normalized column for punctuated name search (R.E.M., AC/DC)

Add index-time normalization and query-time single-letter collapsing to
fix FTS5 search for punctuated names. A new search_normalized column
stores concatenated forms of punctuated words (e.g., "R.E.M." → "REM",
"AC/DC" → "ACDC") and is indexed in FTS5 tables. At query time, runs of
consecutive single letters (from dot-stripping) are collapsed into OR
expressions like ("R E M" OR REM*) to match both the original tokens and
the normalized form. This enables searching by "R.E.M.", "REM", "AC/DC",
"ACDC", "A-ha", or "Aha" and finding the correct results.

* refactor: simplify isSingleUnicodeLetter to avoid []rune allocation

Use utf8.DecodeRuneInString to check for a single Unicode letter
instead of converting the entire string to a []rune slice.

* feat: define ftsSearchColumns for flexible FTS5 search column inclusion

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: update collapseSingleLetterRuns to return quoted phrases for abbreviations

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: implement extractPunctuatedWords to handle artist/album names with embedded punctuation

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: implement extractPunctuatedWords to handle artist/album names with embedded punctuation

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor: punctuated word handling to improve processing of artist/album names

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: add CJK support for search queries with LIKE filters

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: enhance FTS5 search by adding album version support and CJK handling

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor: search configuration to use structured options

Signed-off-by: Deluan <deluan@navidrome.org>

* feat: enhance search functionality to support punctuation-only queries and update related tests

Signed-off-by: Deluan <deluan@navidrome.org>

---------

Signed-off-by: Deluan <deluan@navidrome.org>

persistence/album_repository.go

@@ -62,11 +62,14 @@ func (a *dbAlbum) PostScan() error {
 
 func (a *dbAlbum) PostMapArgs(args map[string]any) error {
 	fullText := []string{a.Name, a.SortAlbumName, a.AlbumArtist}
-	fullText = append(fullText, a.Album.Participants.AllNames()...)
+	participantNames := a.Album.Participants.AllNames()
+	fullText = append(fullText, participantNames...)
 	fullText = append(fullText, slices.Collect(maps.Values(a.Album.Discs))...)
 	fullText = append(fullText, a.Album.Tags[model.TagAlbumVersion]...)
 	fullText = append(fullText, a.Album.Tags[model.TagCatalogNumber]...)
 	args["full_text"] = formatFullText(fullText...)
+	args["search_participants"] = strings.Join(participantNames, " ")
+	args["search_normalized"] = normalizeForFTS(a.Name, a.AlbumArtist)
 
 	args["tags"] = marshalTags(a.Album.Tags)
 	args["participants"] = marshalParticipants(a.Album.Participants)

persistence/album_repository_test.go

@@ -56,17 +56,23 @@ var _ = Describe("AlbumRepository", func() {
 		It("returns all records sorted", func() {
 			Expect(GetAll(model.QueryOptions{Sort: "name"})).To(Equal(model.Albums{
 				albumAbbeyRoad,
+				albumWithVersion,
+				albumCJK,
 				albumMultiDisc,
 				albumRadioactivity,
 				albumSgtPeppers,
+				albumPunctuation,
 			}))
 		})
 
 		It("returns all records sorted desc", func() {
 			Expect(GetAll(model.QueryOptions{Sort: "name", Order: "desc"})).To(Equal(model.Albums{
+				albumPunctuation,
 				albumSgtPeppers,
 				albumRadioactivity,
 				albumMultiDisc,
+				albumCJK,
+				albumWithVersion,
 				albumAbbeyRoad,
 			}))
 		})

persistence/artist_repository.go

@@ -102,6 +102,7 @@ func (a *dbArtist) PostMapArgs(m map[string]any) error {
 	similarArtists, _ := json.Marshal(sa)
 	m["similar_artists"] = string(similarArtists)
 	m["full_text"] = formatFullText(a.Name, a.SortArtistName)
+	m["search_normalized"] = normalizeForFTS(a.Name)
 
 	// Do not override the sort_artist_name and mbz_artist_id fields if they are empty
 	// TODO: Better way to handle this?

persistence/artist_repository_test.go

@@ -193,7 +193,7 @@ var _ = Describe("ArtistRepository", func() {
 		Describe("Basic Operations", func() {
 			Describe("Count", func() {
 				It("returns the number of artists in the DB", func() {
-					Expect(repo.CountAll()).To(Equal(int64(2)))
+					Expect(repo.CountAll()).To(Equal(int64(4)))
 				})
 			})
 
@@ -228,13 +228,19 @@ var _ = Describe("ArtistRepository", func() {
 
 					idx, err := repo.GetIndex(false, []int{1})
 					Expect(err).ToNot(HaveOccurred())
-					Expect(idx).To(HaveLen(2))
+					Expect(idx).To(HaveLen(4))
 					Expect(idx[0].ID).To(Equal("F"))
 					Expect(idx[0].Artists).To(HaveLen(1))
 					Expect(idx[0].Artists[0].Name).To(Equal(artistBeatles.Name))
 					Expect(idx[1].ID).To(Equal("K"))
 					Expect(idx[1].Artists).To(HaveLen(1))
 					Expect(idx[1].Artists[0].Name).To(Equal(artistKraftwerk.Name))
+					Expect(idx[2].ID).To(Equal("R"))
+					Expect(idx[2].Artists).To(HaveLen(1))
+					Expect(idx[2].Artists[0].Name).To(Equal(artistPunctuation.Name))
+					Expect(idx[3].ID).To(Equal("S"))
+					Expect(idx[3].Artists).To(HaveLen(1))
+					Expect(idx[3].Artists[0].Name).To(Equal(artistCJK.Name))
 
 					// Restore the original value
 					artistBeatles.SortArtistName = ""
@@ -246,13 +252,19 @@ var _ = Describe("ArtistRepository", func() {
 				XIt("returns the index when PreferSortTags is true and SortArtistName is empty", func() {
 					idx, err := repo.GetIndex(false, []int{1})
 					Expect(err).ToNot(HaveOccurred())
-					Expect(idx).To(HaveLen(2))
+					Expect(idx).To(HaveLen(4))
 					Expect(idx[0].ID).To(Equal("B"))
 					Expect(idx[0].Artists).To(HaveLen(1))
 					Expect(idx[0].Artists[0].Name).To(Equal(artistBeatles.Name))
 					Expect(idx[1].ID).To(Equal("K"))
 					Expect(idx[1].Artists).To(HaveLen(1))
 					Expect(idx[1].Artists[0].Name).To(Equal(artistKraftwerk.Name))
+					Expect(idx[2].ID).To(Equal("R"))
+					Expect(idx[2].Artists).To(HaveLen(1))
+					Expect(idx[2].Artists[0].Name).To(Equal(artistPunctuation.Name))
+					Expect(idx[3].ID).To(Equal("S"))
+					Expect(idx[3].Artists).To(HaveLen(1))
+					Expect(idx[3].Artists[0].Name).To(Equal(artistCJK.Name))
 				})
 			})
 
@@ -268,13 +280,19 @@ var _ = Describe("ArtistRepository", func() {
 
 					idx, err := repo.GetIndex(false, []int{1})
 					Expect(err).ToNot(HaveOccurred())
-					Expect(idx).To(HaveLen(2))
+					Expect(idx).To(HaveLen(4))
 					Expect(idx[0].ID).To(Equal("B"))
 					Expect(idx[0].Artists).To(HaveLen(1))
 					Expect(idx[0].Artists[0].Name).To(Equal(artistBeatles.Name))
 					Expect(idx[1].ID).To(Equal("K"))
 					Expect(idx[1].Artists).To(HaveLen(1))
 					Expect(idx[1].Artists[0].Name).To(Equal(artistKraftwerk.Name))
+					Expect(idx[2].ID).To(Equal("R"))
+					Expect(idx[2].Artists).To(HaveLen(1))
+					Expect(idx[2].Artists[0].Name).To(Equal(artistPunctuation.Name))
+					Expect(idx[3].ID).To(Equal("S"))
+					Expect(idx[3].Artists).To(HaveLen(1))
+					Expect(idx[3].Artists[0].Name).To(Equal(artistCJK.Name))
 
 					// Restore the original value
 					artistBeatles.SortArtistName = ""
@@ -285,13 +303,19 @@ var _ = Describe("ArtistRepository", func() {
 				It("returns the index when SortArtistName is empty", func() {
 					idx, err := repo.GetIndex(false, []int{1})
 					Expect(err).ToNot(HaveOccurred())
-					Expect(idx).To(HaveLen(2))
+					Expect(idx).To(HaveLen(4))
 					Expect(idx[0].ID).To(Equal("B"))
 					Expect(idx[0].Artists).To(HaveLen(1))
 					Expect(idx[0].Artists[0].Name).To(Equal(artistBeatles.Name))
 					Expect(idx[1].ID).To(Equal("K"))
 					Expect(idx[1].Artists).To(HaveLen(1))
 					Expect(idx[1].Artists[0].Name).To(Equal(artistKraftwerk.Name))
+					Expect(idx[2].ID).To(Equal("R"))
+					Expect(idx[2].Artists).To(HaveLen(1))
+					Expect(idx[2].Artists[0].Name).To(Equal(artistPunctuation.Name))
+					Expect(idx[3].ID).To(Equal("S"))
+					Expect(idx[3].Artists).To(HaveLen(1))
+					Expect(idx[3].Artists[0].Name).To(Equal(artistCJK.Name))
 				})
 			})
 
@@ -377,7 +401,7 @@ var _ = Describe("ArtistRepository", func() {
 					// Admin users can see all content when valid library IDs are provided
 					idx, err := repo.GetIndex(false, []int{1})
 					Expect(err).ToNot(HaveOccurred())
-					Expect(idx).To(HaveLen(2))
+					Expect(idx).To(HaveLen(4))
 
 					// With non-existent library ID, admin users see no content because no artists are associated with that library
 					idx, err = repo.GetIndex(false, []int{999})
@@ -625,11 +649,11 @@ var _ = Describe("ArtistRepository", func() {
 			It("sees all artists regardless of library permissions", func() {
 				count, err := repo.CountAll()
 				Expect(err).ToNot(HaveOccurred())
-				Expect(count).To(Equal(int64(2)))
+				Expect(count).To(Equal(int64(4)))
 
 				artists, err := repo.GetAll()
 				Expect(err).ToNot(HaveOccurred())
-				Expect(artists).To(HaveLen(2))
+				Expect(artists).To(HaveLen(4))
 
 				exists, err := repo.Exists(artistBeatles.ID)
 				Expect(err).ToNot(HaveOccurred())
@@ -661,7 +685,7 @@ var _ = Describe("ArtistRepository", func() {
 				// Should see missing artist in GetAll by default for admin users
 				artists, err := repo.GetAll()
 				Expect(err).ToNot(HaveOccurred())
-				Expect(artists).To(HaveLen(3)) // Including the missing artist
+				Expect(artists).To(HaveLen(5)) // Including the missing artist
 
 				// Search never returns missing artists (hardcoded behavior)
 				results, err := repo.Search("Missing Artist", 0, 10)
@@ -767,19 +791,19 @@ var _ = Describe("ArtistRepository", func() {
 			It("CountAll returns correct count after gaining access", func() {
 				count, err := restrictedRepo.CountAll()
 				Expect(err).ToNot(HaveOccurred())
-				Expect(count).To(Equal(int64(2))) // Beatles and Kraftwerk
+				Expect(count).To(Equal(int64(4))) // Beatles, Kraftwerk, Seatbelts, and The Roots
 			})
 
 			It("GetAll returns artists after gaining access", func() {
 				artists, err := restrictedRepo.GetAll()
 				Expect(err).ToNot(HaveOccurred())
-				Expect(artists).To(HaveLen(2))
+				Expect(artists).To(HaveLen(4))
 
 				var names []string
 				for _, artist := range artists {
 					names = append(names, artist.Name)
 				}
-				Expect(names).To(ContainElements("The Beatles", "Kraftwerk"))
+				Expect(names).To(ContainElements("The Beatles", "Kraftwerk", "シートベルツ", "The Roots"))
 			})
 
 			It("Exists returns true for accessible artists", func() {
@@ -796,7 +820,7 @@ var _ = Describe("ArtistRepository", func() {
 				// With valid library access, should see artists
 				idx, err := restrictedRepo.GetIndex(false, []int{1})
 				Expect(err).ToNot(HaveOccurred())
-				Expect(idx).To(HaveLen(2))
+				Expect(idx).To(HaveLen(4))
 
 				// With non-existent library ID, should see nothing (non-admin user)
 				idx, err = restrictedRepo.GetIndex(false, []int{999})

persistence/mediafile_repository.go

@@ -58,8 +58,11 @@ func (m *dbMediaFile) PostScan() error {
 func (m *dbMediaFile) PostMapArgs(args map[string]any) error {
 	fullText := []string{m.FullTitle(), m.Album, m.Artist, m.AlbumArtist,
 		m.SortTitle, m.SortAlbumName, m.SortArtistName, m.SortAlbumArtistName, m.DiscSubtitle}
-	fullText = append(fullText, m.MediaFile.Participants.AllNames()...)
+	participantNames := m.MediaFile.Participants.AllNames()
+	fullText = append(fullText, participantNames...)
 	args["full_text"] = formatFullText(fullText...)
+	args["search_participants"] = strings.Join(participantNames, " ")
+	args["search_normalized"] = normalizeForFTS(m.FullTitle(), m.Album, m.Artist, m.AlbumArtist)
 	args["tags"] = marshalTags(m.MediaFile.Tags)
 	args["participants"] = marshalParticipants(m.MediaFile.Participants)
 	return nil

persistence/mediafile_repository_test.go

@@ -39,7 +39,7 @@ var _ = Describe("MediaRepository", func() {
 	})
 
 	It("counts the number of mediafiles in the DB", func() {
-		Expect(mr.CountAll()).To(Equal(int64(10)))
+		Expect(mr.CountAll()).To(Equal(int64(13)))
 	})
 
 	Describe("CountBySuffix", func() {

persistence/persistence_suite_test.go

@@ -56,12 +56,22 @@ func al(al model.Album) model.Album {
 	return al
 }
 
+func alWithTags(a model.Album, tags model.Tags) model.Album {
+	a = al(a)
+	a.Tags = tags
+	return a
+}
+
 var (
-	artistKraftwerk = model.Artist{ID: "2", Name: "Kraftwerk", OrderArtistName: "kraftwerk"}
-	artistBeatles   = model.Artist{ID: "3", Name: "The Beatles", OrderArtistName: "beatles"}
-	testArtists     = model.Artists{
+	artistKraftwerk   = model.Artist{ID: "2", Name: "Kraftwerk", OrderArtistName: "kraftwerk"}
+	artistBeatles     = model.Artist{ID: "3", Name: "The Beatles", OrderArtistName: "beatles"}
+	artistCJK         = model.Artist{ID: "4", Name: "シートベルツ", SortArtistName: "Seatbelts", OrderArtistName: "seatbelts"}
+	artistPunctuation = model.Artist{ID: "5", Name: "The Roots", OrderArtistName: "roots"}
+	testArtists       = model.Artists{
 		artistKraftwerk,
 		artistBeatles,
+		artistCJK,
+		artistPunctuation,
 	}
 )
 
@@ -70,11 +80,18 @@ var (
 	albumAbbeyRoad     = al(model.Album{ID: "102", Name: "Abbey Road", AlbumArtist: "The Beatles", OrderAlbumName: "abbey road", AlbumArtistID: "3", EmbedArtPath: p("/beatles/1/come together.mp3"), SongCount: 1, MaxYear: 1969})
 	albumRadioactivity = al(model.Album{ID: "103", Name: "Radioactivity", AlbumArtist: "Kraftwerk", OrderAlbumName: "radioactivity", AlbumArtistID: "2", EmbedArtPath: p("/kraft/radio/radio.mp3"), SongCount: 2})
 	albumMultiDisc     = al(model.Album{ID: "104", Name: "Multi Disc Album", AlbumArtist: "Test Artist", OrderAlbumName: "multi disc album", AlbumArtistID: "1", EmbedArtPath: p("/test/multi/disc1/track1.mp3"), SongCount: 4})
-	testAlbums         = model.Albums{
+	albumCJK           = al(model.Album{ID: "105", Name: "COWBOY BEBOP", AlbumArtist: "シートベルツ", OrderAlbumName: "cowboy bebop", AlbumArtistID: "4", EmbedArtPath: p("/seatbelts/cowboy-bebop/track1.mp3"), SongCount: 1})
+	albumWithVersion   = alWithTags(model.Album{ID: "106", Name: "Abbey Road", AlbumArtist: "The Beatles", OrderAlbumName: "abbey road", AlbumArtistID: "3", EmbedArtPath: p("/beatles/2/come together.mp3"), SongCount: 1, MaxYear: 2019},
+		model.Tags{model.TagAlbumVersion: {"Deluxe Edition"}})
+	albumPunctuation = al(model.Album{ID: "107", Name: "Things Fall Apart", AlbumArtist: "The Roots", OrderAlbumName: "things fall apart", AlbumArtistID: "5", EmbedArtPath: p("/roots/things/track1.mp3"), SongCount: 1})
+	testAlbums       = model.Albums{
 		albumSgtPeppers,
 		albumAbbeyRoad,
 		albumRadioactivity,
 		albumMultiDisc,
+		albumCJK,
+		albumWithVersion,
+		albumPunctuation,
 	}
 )
 
@@ -101,6 +118,9 @@ var (
 	songDisc1Track01 = mf(model.MediaFile{ID: "2002", Title: "Disc 1 Track 1", ArtistID: "1", Artist: "Test Artist", AlbumID: "104", Album: "Multi Disc Album", DiscNumber: 1, TrackNumber: 1, Path: p("/test/multi/disc1/track1.mp3"), OrderAlbumName: "multi disc album", OrderArtistName: "test artist"})
 	songDisc2Track01 = mf(model.MediaFile{ID: "2003", Title: "Disc 2 Track 1", ArtistID: "1", Artist: "Test Artist", AlbumID: "104", Album: "Multi Disc Album", DiscNumber: 2, TrackNumber: 1, Path: p("/test/multi/disc2/track1.mp3"), OrderAlbumName: "multi disc album", OrderArtistName: "test artist"})
 	songDisc1Track02 = mf(model.MediaFile{ID: "2004", Title: "Disc 1 Track 2", ArtistID: "1", Artist: "Test Artist", AlbumID: "104", Album: "Multi Disc Album", DiscNumber: 1, TrackNumber: 2, Path: p("/test/multi/disc1/track2.mp3"), OrderAlbumName: "multi disc album", OrderArtistName: "test artist"})
+	songCJK          = mf(model.MediaFile{ID: "3001", Title: "プラチナ・ジェット", ArtistID: "4", Artist: "シートベルツ", AlbumID: "105", Album: "COWBOY BEBOP", Path: p("/seatbelts/cowboy-bebop/track1.mp3")})
+	songVersioned    = mf(model.MediaFile{ID: "3002", Title: "Come Together", ArtistID: "3", Artist: "The Beatles", AlbumID: "106", Album: "Abbey Road", Path: p("/beatles/2/come together.mp3")})
+	songPunctuation  = mf(model.MediaFile{ID: "3003", Title: "!!!!!!!", ArtistID: "5", Artist: "The Roots", AlbumID: "107", Album: "Things Fall Apart", Path: p("/roots/things/track1.mp3")})
 	testSongs        = model.MediaFiles{
 		songDayInALife,
 		songComeTogether,
@@ -112,6 +132,9 @@ var (
 		songDisc1Track01,
 		songDisc2Track01,
 		songDisc1Track02,
+		songCJK,
+		songVersioned,
+		songPunctuation,
 	}
 )
 

persistence/sql_restful.go

@@ -109,9 +109,10 @@ func booleanFilter(field string, value any) Sqlizer {
 func fullTextFilter(tableName string, mbidFields ...string) func(string, any) Sqlizer {
 	return func(field string, value any) Sqlizer {
 		v := strings.ToLower(value.(string))
+		searchExpr := getSearchExpr()
 		cond := cmp.Or(
 			mbidExpr(tableName, v, mbidFields...),
-			fullTextExpr(tableName, v),
+			searchExpr(tableName, v),
 		)
 		return cond
 	}

persistence/sql_restful_test.go

@@ -26,7 +26,9 @@ var _ = Describe("sqlRestful", func() {
 			Expect(r.parseRestFilters(context.Background(), options)).To(BeNil())
 		})
 
-		It(`returns nil if tries a filter with fullTextExpr("'")`, func() {
+		It(`returns nil if tries a filter with legacySearchExpr("'")`, func() {
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.Search.Backend = "legacy"
 			r.filterMappings = map[string]filterFunc{
 				"name": fullTextFilter("table"),
 			}
@@ -77,6 +79,7 @@ var _ = Describe("sqlRestful", func() {
 
 		BeforeEach(func() {
 			DeferCleanup(configtest.SetupConfig())
+			conf.Server.Search.Backend = "legacy"
 			tableName = "test_table"
 			mbidFields = []string{"mbid", "artist_mbid"}
 			filter = fullTextFilter(tableName, mbidFields...)
@@ -136,7 +139,7 @@ var _ = Describe("sqlRestful", func() {
 
 		Context("when SearchFullString config changes behavior", func() {
 			It("uses different separator with SearchFullString=false", func() {
-				conf.Server.SearchFullString = false
+				conf.Server.Search.FullString = false
 				result := filter("search", "test query")
 
 				andCondition, ok := result.(squirrel.And)
@@ -149,7 +152,7 @@ var _ = Describe("sqlRestful", func() {
 			})
 
 			It("uses no separator with SearchFullString=true", func() {
-				conf.Server.SearchFullString = true
+				conf.Server.Search.FullString = true
 				result := filter("search", "test query")
 
 				andCondition, ok := result.(squirrel.And)

persistence/sql_search.go

@@ -6,6 +6,7 @@ import (
 	. "github.com/Masterminds/squirrel"
 	"github.com/google/uuid"
 	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/utils/str"
 )
@@ -15,6 +16,26 @@ func formatFullText(text ...string) string {
 	return " " + fullText
 }
 
+// searchExprFunc is the function signature for search expression builders.
+type searchExprFunc func(tableName string, query string) Sqlizer
+
+// getSearchExpr returns the active search expression function based on config.
+// It falls back to legacySearchExpr when Search.FullString is enabled, because
+// FTS5 is token-based and cannot match substrings within words.
+// CJK queries are routed to likeSearchExpr, since FTS5's unicode61 tokenizer
+// cannot segment CJK text.
+func getSearchExpr() searchExprFunc {
+	if conf.Server.Search.Backend == "legacy" || conf.Server.Search.FullString {
+		return legacySearchExpr
+	}
+	return func(tableName, query string) Sqlizer {
+		if containsCJK(query) {
+			return likeSearchExpr(tableName, query)
+		}
+		return ftsSearchExpr(tableName, query)
+	}
+}
+
 // doSearch performs a full-text search with the specified parameters.
 // The naturalOrder is used to sort results when no full-text filter is applied. It is useful for cases like
 // OpenSubsonic, where an empty search query should return all results in a natural order. Normally the parameter
@@ -26,7 +47,8 @@ func (r sqlRepository) doSearch(sq SelectBuilder, q string, offset, size int, re
 		return nil
 	}
 
-	filter := fullTextExpr(r.tableName, q)
+	searchExpr := getSearchExpr()
+	filter := searchExpr(r.tableName, q)
 	if filter != nil {
 		sq = sq.Where(filter)
 		sq = sq.OrderBy(orderBys...)
@@ -59,13 +81,16 @@ func mbidExpr(tableName, mbid string, mbidFields ...string) Sqlizer {
 	return Or(cond)
 }
 
-func fullTextExpr(tableName string, s string) Sqlizer {
+// legacySearchExpr generates LIKE-based search filters against the full_text column.
+// This is the original search implementation, used when Search.Backend="legacy".
+func legacySearchExpr(tableName string, s string) Sqlizer {
 	q := str.SanitizeStrings(s)
 	if q == "" {
+		log.Trace("Search using legacy backend, query is empty", "table", tableName)
 		return nil
 	}
 	var sep string
-	if !conf.Server.SearchFullString {
+	if !conf.Server.Search.FullString {
 		sep = " "
 	}
 	parts := strings.Split(q, " ")
@@ -73,5 +98,6 @@ func fullTextExpr(tableName string, s string) Sqlizer {
 	for _, part := range parts {
 		filters = append(filters, Like{tableName + ".full_text": "%" + sep + part + "%"})
 	}
+	log.Trace("Search using legacy backend", "query", filters, "table", tableName)
 	return filters
 }

persistence/sql_search_fts.go

@@ -0,0 +1,261 @@
+package persistence
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	. "github.com/Masterminds/squirrel"
+	"github.com/navidrome/navidrome/log"
+)
+
+// containsCJK returns true if the string contains any CJK (Chinese/Japanese/Korean) characters.
+// CJK text doesn't use spaces between words, so FTS5's unicode61 tokenizer treats entire
+// CJK phrases as single tokens, making token-based search ineffective for CJK content.
+func containsCJK(s string) bool {
+	for _, r := range s {
+		if unicode.Is(unicode.Han, r) ||
+			unicode.Is(unicode.Hiragana, r) ||
+			unicode.Is(unicode.Katakana, r) ||
+			unicode.Is(unicode.Hangul, r) {
+			return true
+		}
+	}
+	return false
+}
+
+// fts5SpecialChars matches characters that should be stripped from user input.
+// We keep only Unicode letters, numbers, whitespace, * (prefix wildcard), " (phrase quotes),
+// and \x00 (internal placeholder marker). All punctuation is removed because the unicode61
+// tokenizer treats it as token separators, and characters like ' can cause FTS5 parse errors
+// as unbalanced string delimiters.
+var fts5SpecialChars = regexp.MustCompile(`[^\p{L}\p{N}\s*"\x00]`)
+
+// fts5PunctStrip strips everything except letters and numbers (no whitespace, wildcards, or quotes).
+// Used for normalizing words at index time to create concatenated forms (e.g., "R.E.M." → "REM").
+var fts5PunctStrip = regexp.MustCompile(`[^\p{L}\p{N}]`)
+
+// fts5Operators matches FTS5 boolean operators as whole words (case-insensitive).
+var fts5Operators = regexp.MustCompile(`(?i)\b(AND|OR|NOT|NEAR)\b`)
+
+// fts5LeadingStar matches a * at the start of a token. FTS5 only supports * at the end (prefix queries).
+var fts5LeadingStar = regexp.MustCompile(`(^|[\s])\*+`)
+
+// normalizeForFTS takes multiple strings, strips non-letter/non-number characters from each word,
+// and returns a space-separated string of words that changed after stripping (deduplicated).
+// This is used at index time to create concatenated forms: "R.E.M." → "REM", "AC/DC" → "ACDC".
+func normalizeForFTS(values ...string) string {
+	seen := make(map[string]struct{})
+	var result []string
+	for _, v := range values {
+		for _, word := range strings.Fields(v) {
+			stripped := fts5PunctStrip.ReplaceAllString(word, "")
+			if stripped == "" || stripped == word {
+				continue
+			}
+			lower := strings.ToLower(stripped)
+			if _, ok := seen[lower]; ok {
+				continue
+			}
+			seen[lower] = struct{}{}
+			result = append(result, stripped)
+		}
+	}
+	return strings.Join(result, " ")
+}
+
+// isSingleUnicodeLetter returns true if token is exactly one Unicode letter.
+func isSingleUnicodeLetter(token string) bool {
+	r, size := utf8.DecodeRuneInString(token)
+	return size == len(token) && size > 0 && unicode.IsLetter(r)
+}
+
+// namePunctuation is the set of characters commonly used as separators in artist/album
+// names (hyphens, slashes, dots, apostrophes). Only words containing these are candidates
+// for punctuated-word processing; other special characters (^, :, &) are just stripped.
+const namePunctuation = `-/.''`
+
+// processPunctuatedWords handles words with embedded name punctuation before the general
+// special-character stripping. For each punctuated word it produces either:
+//   - A quoted phrase for dotted abbreviations: R.E.M. → "R E M"
+//   - A phrase+concat OR for other patterns:    a-ha  → ("a ha" OR aha*)
+func processPunctuatedWords(input string, phrases []string) (string, []string) {
+	words := strings.Fields(input)
+	var result []string
+	for _, w := range words {
+		if strings.HasPrefix(w, "\x00") || strings.ContainsAny(w, `*"`) || !strings.ContainsAny(w, namePunctuation) {
+			result = append(result, w)
+			continue
+		}
+		concat := fts5PunctStrip.ReplaceAllString(w, "")
+		if concat == "" || concat == w {
+			result = append(result, w)
+			continue
+		}
+		subTokens := strings.Fields(fts5SpecialChars.ReplaceAllString(w, " "))
+		if len(subTokens) < 2 {
+			// Single sub-token after splitting (e.g., N' → N): just use the stripped form
+			result = append(result, concat)
+			continue
+		}
+		// Dotted abbreviations (R.E.M., U.K.) — all single letters separated by dots only
+		if isDottedAbbreviation(w, subTokens) {
+			phrases = append(phrases, fmt.Sprintf(`"%s"`, strings.Join(subTokens, " ")))
+		} else {
+			// Punctuated names (a-ha, AC/DC, Jay-Z) — phrase for adjacency + concat for search_normalized
+			phrases = append(phrases, fmt.Sprintf(`("%s" OR %s*)`, strings.Join(subTokens, " "), concat))
+		}
+		result = append(result, fmt.Sprintf("\x00PHRASE%d\x00", len(phrases)-1))
+	}
+	return strings.Join(result, " "), phrases
+}
+
+// isDottedAbbreviation returns true if w uses only dots as punctuation and all sub-tokens
+// are single letters (e.g., "R.E.M.", "U.K." but not "a-ha" or "AC/DC").
+func isDottedAbbreviation(w string, subTokens []string) bool {
+	for _, r := range w {
+		if !unicode.IsLetter(r) && !unicode.IsNumber(r) && r != '.' {
+			return false
+		}
+	}
+	for _, st := range subTokens {
+		if !isSingleUnicodeLetter(st) {
+			return false
+		}
+	}
+	return true
+}
+
+// buildFTS5Query preprocesses user input into a safe FTS5 MATCH expression.
+// It preserves quoted phrases and * prefix wildcards, neutralizes FTS5 operators
+// (by lowercasing them, since FTS5 operators are case-sensitive) and strips
+// special characters to prevent query injection.
+func buildFTS5Query(userInput string) string {
+	q := strings.TrimSpace(userInput)
+	if q == "" {
+		return ""
+	}
+
+	var phrases []string
+	result := q
+	for {
+		start := strings.Index(result, `"`)
+		if start == -1 {
+			break
+		}
+		end := strings.Index(result[start+1:], `"`)
+		if end == -1 {
+			// Unmatched quote — remove it
+			result = result[:start] + result[start+1:]
+			break
+		}
+		end += start + 1
+		phrase := result[start : end+1] // includes quotes
+		phrases = append(phrases, phrase)
+		result = result[:start] + fmt.Sprintf("\x00PHRASE%d\x00", len(phrases)-1) + result[end+1:]
+	}
+
+	// Neutralize FTS5 operators by lowercasing them (FTS5 operators are case-sensitive:
+	// AND, OR, NOT, NEAR are operators, but and, or, not, near are plain tokens)
+	result = fts5Operators.ReplaceAllStringFunc(result, strings.ToLower)
+
+	// Handle words with embedded punctuation (a-ha, AC/DC, R.E.M.) before stripping
+	result, phrases = processPunctuatedWords(result, phrases)
+
+	result = fts5SpecialChars.ReplaceAllString(result, " ")
+	result = fts5LeadingStar.ReplaceAllString(result, "$1")
+	tokens := strings.Fields(result)
+
+	// Append * to plain tokens for prefix matching (e.g., "love" → "love*").
+	// Skip tokens that are already wildcarded or are quoted phrase placeholders.
+	for i, t := range tokens {
+		if strings.HasPrefix(t, "\x00") || strings.HasSuffix(t, "*") {
+			continue
+		}
+		tokens[i] = t + "*"
+	}
+
+	result = strings.Join(tokens, " ")
+
+	for i, phrase := range phrases {
+		placeholder := fmt.Sprintf("\x00PHRASE%d\x00", i)
+		result = strings.ReplaceAll(result, placeholder, phrase)
+	}
+
+	return result
+}
+
+// likeSearchColumns defines the core columns to search with LIKE queries.
+// These are the primary user-visible fields for each entity type.
+// Used as a fallback when FTS5 cannot handle the query (e.g., CJK text, punctuation-only input).
+var likeSearchColumns = map[string][]string{
+	"media_file": {"title", "album", "artist", "album_artist"},
+	"album":      {"name", "album_artist"},
+	"artist":     {"name"},
+}
+
+// likeSearchExpr generates LIKE-based search filters against core columns.
+// Each word in the query must match at least one column (AND between words),
+// and each word can match any column (OR within a word).
+// Used as a fallback when FTS5 cannot handle the query (e.g., CJK text, punctuation-only input).
+func likeSearchExpr(tableName string, s string) Sqlizer {
+	s = strings.TrimSpace(s)
+	if s == "" {
+		log.Trace("Search using LIKE backend, query is empty", "table", tableName)
+		return nil
+	}
+	columns, ok := likeSearchColumns[tableName]
+	if !ok {
+		log.Trace("Search using LIKE backend, couldn't find columns for this table", "table", tableName)
+		return nil
+	}
+	words := strings.Fields(s)
+	wordFilters := And{}
+	for _, word := range words {
+		colFilters := Or{}
+		for _, col := range columns {
+			colFilters = append(colFilters, Like{tableName + "." + col: "%" + word + "%"})
+		}
+		wordFilters = append(wordFilters, colFilters)
+	}
+	log.Trace("Search using LIKE backend", "query", wordFilters, "table", tableName)
+	return wordFilters
+}
+
+// ftsSearchColumns defines which FTS5 columns are included in general search.
+// Columns not listed here are indexed but not searched by default,
+// enabling future additions (comments, lyrics, bios) without affecting general search.
+var ftsSearchColumns = map[string]string{
+	"media_file": "{title album artist album_artist sort_title sort_album_name sort_artist_name sort_album_artist_name disc_subtitle search_participants search_normalized}",
+	"album":      "{name sort_album_name album_artist search_participants discs catalog_num album_version search_normalized}",
+	"artist":     "{name sort_artist_name search_normalized}",
+}
+
+// ftsSearchExpr generates an FTS5 MATCH-based search filter.
+// If the query produces no FTS tokens (e.g., punctuation-only like "!!!!!!!"),
+// it falls back to LIKE-based search.
+func ftsSearchExpr(tableName string, s string) Sqlizer {
+	q := buildFTS5Query(s)
+	if q == "" {
+		s = strings.TrimSpace(s)
+		if s != "" {
+			log.Trace("Search using LIKE fallback for non-tokenizable query", "table", tableName, "query", s)
+			return likeSearchExpr(tableName, s)
+		}
+		return nil
+	}
+	ftsTable := tableName + "_fts"
+	matchExpr := q
+	if cols, ok := ftsSearchColumns[tableName]; ok {
+		matchExpr = cols + " : (" + q + ")"
+	}
+
+	filter := Expr(
+		tableName+".rowid IN (SELECT rowid FROM "+ftsTable+" WHERE "+ftsTable+" MATCH ?)",
+		matchExpr,
+	)
+	log.Trace("Search using FTS5 backend", "table", tableName, "query", q, "filter", filter)
+	return filter
+}

persistence/sql_search_fts_test.go

@@ -0,0 +1,333 @@
+package persistence
+
+import (
+	"context"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = DescribeTable("buildFTS5Query",
+	func(input, expected string) {
+		Expect(buildFTS5Query(input)).To(Equal(expected))
+	},
+	Entry("returns empty string for empty input", "", ""),
+	Entry("returns empty string for whitespace-only input", "   ", ""),
+	Entry("appends * to a single word for prefix matching", "beatles", "beatles*"),
+	Entry("appends * to each word for prefix matching", "abbey road", "abbey* road*"),
+	Entry("preserves quoted phrases without appending *", `"the beatles"`, `"the beatles"`),
+	Entry("does not double-append * to existing prefix wildcard", "beat*", "beat*"),
+	Entry("strips FTS5 operators and appends * to lowercased words", "AND OR NOT NEAR", "and* or* not* near*"),
+	Entry("strips special FTS5 syntax characters and appends *", "test^col:val", "test* col* val*"),
+	Entry("handles mixed phrases and words", `"the beatles" abbey`, `"the beatles" abbey*`),
+	Entry("handles prefix with multiple words", "beat* abbey", "beat* abbey*"),
+	Entry("collapses multiple spaces", "abbey   road", "abbey* road*"),
+	Entry("strips leading * from tokens and appends trailing *", "*livia", "livia*"),
+	Entry("strips leading * and preserves existing trailing *", "*livia oliv*", "livia* oliv*"),
+	Entry("strips standalone *", "*", ""),
+	Entry("strips apostrophe from input", "Guns N' Roses", "Guns* N* Roses*"),
+	Entry("converts slashed word to phrase+concat OR", "AC/DC", `("AC DC" OR ACDC*)`),
+	Entry("converts hyphenated word to phrase+concat OR", "a-ha", `("a ha" OR aha*)`),
+	Entry("converts partial hyphenated word to phrase+concat OR", "a-h", `("a h" OR ah*)`),
+	Entry("converts hyphenated name to phrase+concat OR", "Jay-Z", `("Jay Z" OR JayZ*)`),
+	Entry("converts contraction to phrase+concat OR", "it's", `("it s" OR its*)`),
+	Entry("handles punctuated word mixed with plain words", "best of a-ha", `best* of* ("a ha" OR aha*)`),
+	Entry("strips miscellaneous punctuation", "rock & roll, vol. 2", "rock* roll* vol* 2*"),
+	Entry("preserves unicode characters with diacritics", "Björk début", "Björk* début*"),
+	Entry("collapses dotted abbreviation into phrase", "R.E.M.", `"R E M"`),
+	Entry("collapses abbreviation without trailing dot", "R.E.M", `"R E M"`),
+	Entry("collapses abbreviation mixed with words", "best of R.E.M.", `best* of* "R E M"`),
+	Entry("collapses two-letter abbreviation", "U.K.", `"U K"`),
+	Entry("does not collapse single letter surrounded by words", "I am fine", "I* am* fine*"),
+	Entry("does not collapse single standalone letter", "A test", "A* test*"),
+	Entry("preserves quoted phrase with punctuation verbatim", `"ac/dc"`, `"ac/dc"`),
+	Entry("preserves quoted abbreviation verbatim", `"R.E.M."`, `"R.E.M."`),
+	Entry("returns empty string for punctuation-only input", "!!!!!!!", ""),
+	Entry("returns empty string for mixed punctuation", "!@#$%^&", ""),
+)
+
+var _ = DescribeTable("normalizeForFTS",
+	func(expected string, values ...string) {
+		Expect(normalizeForFTS(values...)).To(Equal(expected))
+	},
+	Entry("strips dots and concatenates", "REM", "R.E.M."),
+	Entry("strips slash", "ACDC", "AC/DC"),
+	Entry("strips hyphen", "Aha", "A-ha"),
+	Entry("skips unchanged words", "", "The Beatles"),
+	Entry("handles mixed input", "REM", "R.E.M.", "Automatic for the People"),
+	Entry("deduplicates", "REM", "R.E.M.", "R.E.M."),
+	Entry("strips apostrophe from word", "N", "Guns N' Roses"),
+	Entry("handles multiple values with punctuation", "REM ACDC", "R.E.M.", "AC/DC"),
+)
+
+var _ = DescribeTable("containsCJK",
+	func(input string, expected bool) {
+		Expect(containsCJK(input)).To(Equal(expected))
+	},
+	Entry("returns false for empty string", "", false),
+	Entry("returns false for ASCII text", "hello world", false),
+	Entry("returns false for Latin with diacritics", "Björk début", false),
+	Entry("detects Chinese characters (Han)", "周杰伦", true),
+	Entry("detects Japanese Hiragana", "こんにちは", true),
+	Entry("detects Japanese Katakana", "カタカナ", true),
+	Entry("detects Korean Hangul", "한국어", true),
+	Entry("detects CJK mixed with Latin", "best of 周杰伦", true),
+	Entry("detects single CJK character", "a曲b", true),
+)
+
+var _ = Describe("likeSearchExpr", func() {
+	It("returns nil for empty query", func() {
+		Expect(likeSearchExpr("media_file", "")).To(BeNil())
+	})
+
+	It("returns nil for whitespace-only query", func() {
+		Expect(likeSearchExpr("media_file", "   ")).To(BeNil())
+	})
+
+	It("generates LIKE filters against core columns for single CJK word", func() {
+		expr := likeSearchExpr("media_file", "周杰伦")
+		sql, args, err := expr.ToSql()
+		Expect(err).ToNot(HaveOccurred())
+		// Should have OR between columns for the single word
+		Expect(sql).To(ContainSubstring("OR"))
+		Expect(sql).To(ContainSubstring("media_file.title LIKE"))
+		Expect(sql).To(ContainSubstring("media_file.album LIKE"))
+		Expect(sql).To(ContainSubstring("media_file.artist LIKE"))
+		Expect(sql).To(ContainSubstring("media_file.album_artist LIKE"))
+		Expect(args).To(HaveLen(4))
+		for _, arg := range args {
+			Expect(arg).To(Equal("%周杰伦%"))
+		}
+	})
+
+	It("generates AND of OR groups for multi-word query", func() {
+		expr := likeSearchExpr("media_file", "周杰伦 greatest")
+		sql, args, err := expr.ToSql()
+		Expect(err).ToNot(HaveOccurred())
+		// Two groups AND'd together, each with 4 columns OR'd
+		Expect(sql).To(ContainSubstring("AND"))
+		Expect(args).To(HaveLen(8))
+	})
+
+	It("uses correct columns for album table", func() {
+		expr := likeSearchExpr("album", "周杰伦")
+		sql, args, err := expr.ToSql()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(sql).To(ContainSubstring("album.name LIKE"))
+		Expect(sql).To(ContainSubstring("album.album_artist LIKE"))
+		Expect(args).To(HaveLen(2))
+	})
+
+	It("uses correct columns for artist table", func() {
+		expr := likeSearchExpr("artist", "周杰伦")
+		sql, args, err := expr.ToSql()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(sql).To(ContainSubstring("artist.name LIKE"))
+		Expect(args).To(HaveLen(1))
+	})
+
+	It("returns nil for unknown table", func() {
+		Expect(likeSearchExpr("unknown_table", "周杰伦")).To(BeNil())
+	})
+})
+
+var _ = Describe("ftsSearchExpr", func() {
+	It("returns nil for empty query", func() {
+		Expect(ftsSearchExpr("media_file", "")).To(BeNil())
+	})
+
+	It("generates rowid IN subquery with MATCH and column filter", func() {
+		expr := ftsSearchExpr("media_file", "beatles")
+		sql, args, err := expr.ToSql()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(sql).To(ContainSubstring("media_file.rowid IN"))
+		Expect(sql).To(ContainSubstring("media_file_fts"))
+		Expect(sql).To(ContainSubstring("MATCH"))
+		Expect(args).To(HaveLen(1))
+		Expect(args[0]).To(HavePrefix("{title album artist album_artist"))
+		Expect(args[0]).To(ContainSubstring("beatles*"))
+	})
+
+	It("generates correct FTS table name per entity", func() {
+		for _, table := range []string{"media_file", "album", "artist"} {
+			expr := ftsSearchExpr(table, "test")
+			sql, _, err := expr.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(ContainSubstring(table + ".rowid IN"))
+			Expect(sql).To(ContainSubstring(table + "_fts"))
+		}
+	})
+
+	It("wraps query with column filter for known tables", func() {
+		expr := ftsSearchExpr("artist", "Beatles")
+		_, args, err := expr.ToSql()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(args[0]).To(Equal("{name sort_artist_name search_normalized} : (Beatles*)"))
+	})
+
+	It("passes query without column filter for unknown tables", func() {
+		expr := ftsSearchExpr("unknown_table", "test")
+		_, args, err := expr.ToSql()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(args[0]).To(Equal("test*"))
+	})
+
+	It("preserves phrase queries inside column filter", func() {
+		expr := ftsSearchExpr("media_file", `"the beatles"`)
+		_, args, err := expr.ToSql()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(args[0]).To(ContainSubstring(`"the beatles"`))
+	})
+
+	It("preserves prefix queries inside column filter", func() {
+		expr := ftsSearchExpr("media_file", "beat*")
+		_, args, err := expr.ToSql()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(args[0]).To(ContainSubstring("beat*"))
+	})
+
+	It("falls back to LIKE search for punctuation-only query", func() {
+		expr := ftsSearchExpr("media_file", "!!!!!!!")
+		Expect(expr).ToNot(BeNil())
+		sql, args, err := expr.ToSql()
+		Expect(err).ToNot(HaveOccurred())
+		Expect(sql).To(ContainSubstring("LIKE"))
+		Expect(args).To(ContainElement("%!!!!!!!%"))
+	})
+
+	It("returns nil for empty string even with LIKE fallback", func() {
+		Expect(ftsSearchExpr("media_file", "")).To(BeNil())
+		Expect(ftsSearchExpr("media_file", "   ")).To(BeNil())
+	})
+})
+
+var _ = Describe("FTS5 Integration Search", func() {
+	var (
+		mr  model.MediaFileRepository
+		alr model.AlbumRepository
+		arr model.ArtistRepository
+	)
+
+	BeforeEach(func() {
+		ctx := log.NewContext(context.TODO())
+		ctx = request.WithUser(ctx, adminUser)
+		conn := GetDBXBuilder()
+		mr = NewMediaFileRepository(ctx, conn)
+		alr = NewAlbumRepository(ctx, conn)
+		arr = NewArtistRepository(ctx, conn)
+	})
+
+	Describe("MediaFile search", func() {
+		It("finds media files by title", func() {
+			results, err := mr.Search("Radioactivity", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(1))
+			Expect(results[0].Title).To(Equal("Radioactivity"))
+			Expect(results[0].ID).To(Equal(songRadioactivity.ID))
+		})
+
+		It("finds media files by artist name", func() {
+			results, err := mr.Search("Beatles", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(3))
+			for _, r := range results {
+				Expect(r.Artist).To(Equal("The Beatles"))
+			}
+		})
+	})
+
+	Describe("Album search", func() {
+		It("finds albums by name", func() {
+			results, err := alr.Search("Sgt Peppers", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(1))
+			Expect(results[0].Name).To(Equal("Sgt Peppers"))
+			Expect(results[0].ID).To(Equal(albumSgtPeppers.ID))
+		})
+
+		It("finds albums with multi-word search", func() {
+			results, err := alr.Search("Abbey Road", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(2))
+		})
+	})
+
+	Describe("Artist search", func() {
+		It("finds artists by name", func() {
+			results, err := arr.Search("Kraftwerk", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(1))
+			Expect(results[0].Name).To(Equal("Kraftwerk"))
+			Expect(results[0].ID).To(Equal(artistKraftwerk.ID))
+		})
+	})
+
+	Describe("CJK search", func() {
+		It("finds media files by CJK title", func() {
+			results, err := mr.Search("プラチナ", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(1))
+			Expect(results[0].Title).To(Equal("プラチナ・ジェット"))
+			Expect(results[0].ID).To(Equal(songCJK.ID))
+		})
+
+		It("finds media files by CJK artist name", func() {
+			results, err := mr.Search("シートベルツ", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(1))
+			Expect(results[0].Artist).To(Equal("シートベルツ"))
+		})
+
+		It("finds albums by CJK artist name", func() {
+			results, err := alr.Search("シートベルツ", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(1))
+			Expect(results[0].Name).To(Equal("COWBOY BEBOP"))
+			Expect(results[0].ID).To(Equal(albumCJK.ID))
+		})
+
+		It("finds artists by CJK name", func() {
+			results, err := arr.Search("シートベルツ", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(1))
+			Expect(results[0].Name).To(Equal("シートベルツ"))
+			Expect(results[0].ID).To(Equal(artistCJK.ID))
+		})
+	})
+
+	Describe("Album version search", func() {
+		It("finds albums by version tag via FTS", func() {
+			results, err := alr.Search("Deluxe", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(1))
+			Expect(results[0].ID).To(Equal(albumWithVersion.ID))
+		})
+	})
+
+	Describe("Punctuation-only search", func() {
+		It("finds media files with punctuation-only title", func() {
+			results, err := mr.Search("!!!!!!!", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(1))
+			Expect(results[0].Title).To(Equal("!!!!!!!"))
+			Expect(results[0].ID).To(Equal(songPunctuation.ID))
+		})
+	})
+
+	Describe("Legacy backend fallback", func() {
+		It("returns results using legacy LIKE-based search when configured", func() {
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.Search.Backend = "legacy"
+
+			results, err := mr.Search("Radioactivity", 0, 10)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(results).To(HaveLen(1))
+			Expect(results[0].Title).To(Equal("Radioactivity"))
+		})
+	})
+})

persistence/sql_search_test.go

@@ -1,6 +1,8 @@
 package persistence
 
 import (
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
@@ -11,4 +13,99 @@ var _ = Describe("sqlRepository", func() {
 			Expect(formatFullText("legiao urbana")).To(Equal(" legiao urbana"))
 		})
 	})
+
+	Describe("legacySearchExpr", func() {
+		It("returns nil for empty query", func() {
+			Expect(legacySearchExpr("media_file", "")).To(BeNil())
+		})
+
+		It("generates LIKE filter for single word", func() {
+			expr := legacySearchExpr("media_file", "beatles")
+			sql, args, err := expr.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(ContainSubstring("media_file.full_text LIKE"))
+			Expect(args).To(ContainElement("% beatles%"))
+		})
+
+		It("generates AND of LIKE filters for multiple words", func() {
+			expr := legacySearchExpr("media_file", "abbey road")
+			sql, args, err := expr.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(ContainSubstring("AND"))
+			Expect(args).To(HaveLen(2))
+		})
+	})
+
+	Describe("getSearchExpr", func() {
+		It("returns ftsSearchExpr by default", func() {
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.Search.Backend = "fts"
+			conf.Server.Search.FullString = false
+
+			expr := getSearchExpr()("media_file", "test")
+			sql, _, err := expr.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(ContainSubstring("MATCH"))
+		})
+
+		It("returns legacySearchExpr when SearchBackend is legacy", func() {
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.Search.Backend = "legacy"
+			conf.Server.Search.FullString = false
+
+			expr := getSearchExpr()("media_file", "test")
+			sql, _, err := expr.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(ContainSubstring("LIKE"))
+		})
+
+		It("falls back to legacySearchExpr when SearchFullString is enabled", func() {
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.Search.Backend = "fts"
+			conf.Server.Search.FullString = true
+
+			expr := getSearchExpr()("media_file", "test")
+			sql, _, err := expr.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(ContainSubstring("LIKE"))
+		})
+
+		It("routes CJK queries to likeSearchExpr instead of ftsSearchExpr", func() {
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.Search.Backend = "fts"
+			conf.Server.Search.FullString = false
+
+			expr := getSearchExpr()("media_file", "周杰伦")
+			sql, _, err := expr.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			// CJK should use LIKE, not MATCH
+			Expect(sql).To(ContainSubstring("LIKE"))
+			Expect(sql).NotTo(ContainSubstring("MATCH"))
+		})
+
+		It("routes non-CJK queries to ftsSearchExpr", func() {
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.Search.Backend = "fts"
+			conf.Server.Search.FullString = false
+
+			expr := getSearchExpr()("media_file", "beatles")
+			sql, _, err := expr.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(ContainSubstring("MATCH"))
+		})
+
+		It("uses legacy for CJK when SearchBackend is legacy", func() {
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.Search.Backend = "legacy"
+			conf.Server.Search.FullString = false
+
+			expr := getSearchExpr()("media_file", "周杰伦")
+			sql, _, err := expr.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			// Legacy should still use full_text column LIKE
+			Expect(sql).To(ContainSubstring("LIKE"))
+			Expect(sql).To(ContainSubstring("full_text"))
+		})
+	})
+
 })