fix(subsonic): add library filter and dedupe IDs in Exists

Addresses code review feedback: apply library-level access control via
applyLibraryFilter and handle duplicate IDs correctly using slice.Unique.
This prevents users from verifying existence of tracks outside their
accessible libraries and ensures duplicate IDs don't cause false negatives.

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

.devcontainer/Dockerfile

@@ -9,12 +9,21 @@ ARG INSTALL_NODE="true"
 ARG NODE_VERSION="lts/*"
 RUN if [ "${INSTALL_NODE}" = "true" ]; then su vscode -c "source /usr/local/share/nvm/nvm.sh && nvm install ${NODE_VERSION} 2>&1"; fi
 
-# [Optional] Uncomment this section to install additional OS packages.
+# Install additional OS packages
 RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
-    && apt-get -y install --no-install-recommends libtag1-dev ffmpeg
+    && apt-get -y install --no-install-recommends ffmpeg
 
-# [Optional] Uncomment the next line to use go get to install anything else you need
-# RUN go get -x <your-dependency-or-tool>
+# Install TagLib from cross-taglib releases
+ARG CROSS_TAGLIB_VERSION="2.1.1-1"
+ARG TARGETARCH
+RUN DOWNLOAD_ARCH="linux-${TARGETARCH}" \
+    && wget -q "https://github.com/navidrome/cross-taglib/releases/download/v${CROSS_TAGLIB_VERSION}/taglib-${DOWNLOAD_ARCH}.tar.gz" -O /tmp/cross-taglib.tar.gz \
+    && tar -xzf /tmp/cross-taglib.tar.gz -C /usr --strip-components=1 \
+    && mv /usr/include/taglib/* /usr/include/ \
+    && rmdir /usr/include/taglib \
+    && rm /tmp/cross-taglib.tar.gz /usr/provenance.json
+
+ENV CGO_CFLAGS_ALLOW="--define-prefix"
 
 # [Optional] Uncomment this line to install global node packages.
 # RUN su vscode -c "source /usr/local/share/nvm/nvm.sh && npm install -g <your-package-here>" 2>&1

.devcontainer/devcontainer.json

@@ -4,10 +4,11 @@
 		"dockerfile": "Dockerfile",
 		"args": {
 			// Update the VARIANT arg to pick a version of Go: 1, 1.15, 1.14
-			"VARIANT": "1.24",
+			"VARIANT": "1.25",
 			// Options
 			"INSTALL_NODE": "true",
-			"NODE_VERSION": "v20"
+			"NODE_VERSION": "v24",
+			"CROSS_TAGLIB_VERSION": "2.1.1-1"
 		}
 	},
 	"workspaceMount": "",
@@ -54,12 +55,10 @@
 		4533,
 		4633
 	],
-	// Use 'postCreateCommand' to run commands after the container is created.
-	// "postCreateCommand": "make setup-dev",
 	// Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
 	"remoteUser": "vscode",
 	"remoteEnv": {
 		"ND_MUSICFOLDER": "./music",
 		"ND_DATAFOLDER": "./data"
 	}
-}
+}

.github/copilot-instructions.md

@@ -1,53 +0,0 @@
-# Navidrome Code Guidelines
-
-This is a music streaming server written in Go with a React frontend. The application manages music libraries, provides streaming capabilities, and offers various features like artist information, artwork handling, and external service integrations.
-
-## Code Standards
-
-### Backend (Go)
-- Follow standard Go conventions and idioms
-- Use context propagation for cancellation signals
-- Write unit tests for new functionality using Ginkgo/Gomega
-- Use mutex appropriately for concurrent operations
-- Implement interfaces for dependencies to facilitate testing
-
-### Frontend (React)
-- Use functional components with hooks
-- Follow React best practices for state management
-- Implement PropTypes for component properties
-- Prefer using React-Admin and Material-UI components
-- Icons should be imported from `react-icons` only
-- Follow existing patterns for API interaction
-
-## Repository Structure
-- `core/`: Server-side business logic (artwork handling, playback, etc.)
-- `ui/`: React frontend components
-- `model/`: Data models and repository interfaces
-- `server/`: API endpoints and server implementation
-- `utils/`: Shared utility functions
-- `persistence/`: Database access layer
-- `scanner/`: Music library scanning functionality
-
-## Key Guidelines
-1. Maintain cache management patterns for performance
-2. Follow the existing concurrency patterns (mutex, atomic)
-3. Use the testing framework appropriately (Ginkgo/Gomega for Go)
-4. Keep UI components focused and reusable
-5. Document configuration options in code
-6. Consider performance implications when working with music libraries
-7. Follow existing error handling patterns
-8. Ensure compatibility with external services (LastFM, Spotify)
-
-## Development Workflow
-- Test changes thoroughly, especially around concurrent operations
-- Validate both backend and frontend interactions
-- Consider how changes will affect user experience and performance
-- Test with different music library sizes and configurations
-- Before committing, ALWAYS run `make format lint test`, and make sure there are no issues
-
-## Important commands
-- `make build`: Build the application
-- `make test`: Run Go tests
-- To run tests for a specific package, use `make test PKG=./pkgname/...`
-- `make lintall`: Run linters
-- `make format`: Format code

.github/pull_request_template.md

@@ -0,0 +1,38 @@
+### Description
+<!-- Please provide a clear and concise description of what this PR does and why it is needed. -->
+
+### Related Issues
+<!-- List any related issues, e.g., "Fixes #123" or "Related to #456". -->
+
+### Type of Change
+- [ ] Bug fix
+- [ ] New feature
+- [ ] Documentation update
+- [ ] Refactor
+- [ ] Other (please describe):
+
+### Checklist
+Please review and check all that apply:
+
+- [ ] My code follows the project’s coding style
+- [ ] I have tested the changes locally
+- [ ] I have added or updated documentation as needed
+- [ ] I have added tests that prove my fix/feature works (or explain why not)
+- [ ] All existing and new tests pass
+
+### How to Test
+<!-- Describe the steps to test your changes. Include setup, commands, and expected results. -->
+
+### Screenshots / Demos (if applicable)
+<!-- Add screenshots, GIFs, or links to demos if your change includes UI updates or visual changes. -->
+
+### Additional Notes
+<!-- Anything else the maintainer should know? Potential side effects, breaking changes, or areas of concern? -->
+
+<!-- 
+**Tips for Contributors:**
+- Be concise but thorough.
+- If your PR is large, consider breaking it into smaller PRs.
+- Tag the maintainer if you need a prompt review.
+- Avoid force pushing to the branch after opening the PR, as it can complicate the review process.
+-->

.github/workflows/pipeline.yml

@@ -14,7 +14,8 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  CROSS_TAGLIB_VERSION: "2.0.2-1"
+  CROSS_TAGLIB_VERSION: "2.1.1-2"
+  CGO_CFLAGS_ALLOW: "--define-prefix"
   IS_RELEASE: ${{ startsWith(github.ref, 'refs/tags/') && 'true' || 'false' }}
 
 jobs:
@@ -25,7 +26,7 @@ jobs:
       git_tag: ${{ steps.git-version.outputs.GIT_TAG }}
       git_sha: ${{ steps.git-version.outputs.GIT_SHA }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
           fetch-tags: true
@@ -63,7 +64,7 @@ jobs:
     name: Lint Go code
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Download TagLib
         uses: ./.github/actions/download-taglib
@@ -71,14 +72,14 @@ jobs:
           version: ${{ env.CROSS_TAGLIB_VERSION }}
 
       - name: golangci-lint
-        uses: golangci/golangci-lint-action@v8
+        uses: golangci/golangci-lint-action@v9
         with:
           version: latest
           problem-matchers: true
           args: --timeout 2m
 
       - name: Run go goimports
-        run: go run golang.org/x/tools/cmd/goimports@latest -w `find . -name '*.go' | grep -v '_gen.go$'`
+        run: go run golang.org/x/tools/cmd/goimports@latest -w `find . -name '*.go' | grep -v '_gen.go$' | grep -v '.pb.go$'`
       - run: go mod tidy
       - name: Verify no changes from goimports and go mod tidy
         run: |
@@ -88,12 +89,22 @@ jobs:
             exit 1
           fi
 
+      - name: Run go generate
+        run: go generate ./...
+      - name: Verify no changes from go generate
+        run: |
+          git status --porcelain
+          if [ -n "$(git status --porcelain)" ]; then
+            echo 'Generated code is out of date. Run "make gen" and commit the changes'
+            exit 1
+          fi
+
   go:
     name: Test Go code
     runs-on: ubuntu-latest
     steps:
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Download TagLib
         uses: ./.github/actions/download-taglib
@@ -106,7 +117,14 @@ jobs:
       - name: Test
         run: |
           pkg-config --define-prefix --cflags --libs taglib # for debugging
-          go test -shuffle=on -tags netgo -race -cover ./... -v
+          go test -shuffle=on -tags netgo -race ./... -v
+
+      - name: Test ndpgen
+        run: |
+          cd plugins/cmd/ndpgen
+          go test -shuffle=on -v
+          go build -o ndpgen .
+          ./ndpgen --help
 
   js:
     name: Test JS code
@@ -114,10 +132,10 @@ jobs:
     env:
       NODE_OPTIONS: "--max_old_space_size=4096"
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v6
+      - uses: actions/setup-node@v6
         with:
-          node-version: 20
+          node-version: 24
           cache: "npm"
           cache-dependency-path: "**/package-lock.json"
 
@@ -145,7 +163,7 @@ jobs:
     name: Lint i18n files
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - run: |
           set -e
           for file in resources/i18n/*.json; do
@@ -157,6 +175,8 @@ jobs:
               exit 1
             fi
           done
+      - run: ./.github/workflows/validate-translations.sh -v
+
 
   check-push-enabled:
     name: Check Docker configuration
@@ -173,7 +193,7 @@ jobs:
     needs: [js, go, go-lint, i18n-lint, git-version, check-push-enabled]
     strategy:
       matrix:
-        platform: [ linux/amd64, linux/arm64, linux/arm/v5, linux/arm/v6, linux/arm/v7, linux/386, darwin/amd64, darwin/arm64, windows/amd64, windows/386 ]
+        platform: [ linux/amd64, linux/arm64, linux/arm/v5, linux/arm/v6, linux/arm/v7, linux/386, linux/riscv64, darwin/amd64, darwin/arm64, windows/amd64, windows/386 ]
     runs-on: ubuntu-latest
     env:
       IS_LINUX: ${{ startsWith(matrix.platform, 'linux/') && 'true' || 'false' }}
@@ -189,7 +209,7 @@ jobs:
           PLATFORM=$(echo ${{ matrix.platform }} | tr '/' '_')
           echo "PLATFORM=$PLATFORM" >> $GITHUB_ENV
 
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Prepare Docker Buildx
         uses: ./.github/actions/prepare-docker
@@ -215,7 +235,7 @@ jobs:
             CROSS_TAGLIB_VERSION=${{ env.CROSS_TAGLIB_VERSION }}
 
       - name: Upload Binaries
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: navidrome-${{ env.PLATFORM }}
           path: ./output
@@ -246,7 +266,7 @@ jobs:
           touch "/tmp/digests/${digest#sha256:}"          
 
       - name: Upload digest
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         if: env.IS_LINUX == 'true' && env.IS_DOCKER_PUSH_CONFIGURED == 'true' && env.IS_ARMV5 == 'false'
         with:
           name: digests-${{ env.PLATFORM }}
@@ -254,18 +274,55 @@ jobs:
           if-no-files-found: error
           retention-days: 1
 
-  push-manifest:
-    name: Push Docker manifest
+  push-manifest-ghcr:
+    name: Push to GHCR
+    permissions:
+      contents: read
+      packages: write
     runs-on: ubuntu-latest
     needs: [build, check-push-enabled]
     if: needs.check-push-enabled.outputs.is_enabled == 'true'
     env:
       REGISTRY_IMAGE: ghcr.io/${{ github.repository }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Download digests
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v7
+        with:
+          path: /tmp/digests
+          pattern: digests-*
+          merge-multiple: true
+
+      - name: Prepare Docker Buildx
+        uses: ./.github/actions/prepare-docker
+        id: docker
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Create manifest list and push to ghcr.io
+        working-directory: /tmp/digests
+        run: |
+          docker buildx imagetools create $(jq -cr '.tags | map(select(startswith("ghcr.io"))) | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
+            $(printf '${{ env.REGISTRY_IMAGE }}@sha256:%s ' *)          
+
+      - name: Inspect image in ghcr.io
+        run: |
+          docker buildx imagetools inspect ${{ env.REGISTRY_IMAGE }}:${{ steps.docker.outputs.version }}
+
+  push-manifest-dockerhub:
+    name: Push to Docker Hub
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    needs: [build, check-push-enabled]
+    if: needs.check-push-enabled.outputs.is_enabled == 'true' && vars.DOCKER_HUB_REPO != ''
+    continue-on-error: true
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download digests
+        uses: actions/download-artifact@v7
         with:
           path: /tmp/digests
           pattern: digests-*
@@ -280,28 +337,27 @@ jobs:
           hub_username: ${{ secrets.DOCKER_HUB_USERNAME }}
           hub_password: ${{ secrets.DOCKER_HUB_PASSWORD }}
 
-      - name: Create manifest list and push to ghcr.io
-        working-directory: /tmp/digests
-        run: |
-          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
-            $(printf '${{ env.REGISTRY_IMAGE }}@sha256:%s ' *)          
-
       - name: Create manifest list and push to Docker Hub
-        working-directory: /tmp/digests
-        if: vars.DOCKER_HUB_REPO != ''
-        run: |
-          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
-            $(printf '${{ vars.DOCKER_HUB_REPO }}@sha256:%s ' *)          
-
-      - name: Inspect image in ghcr.io
-        run: |
-          docker buildx imagetools inspect ${{ env.REGISTRY_IMAGE }}:${{ steps.docker.outputs.version }}
+        uses: nick-fields/retry@v3
+        with:
+          timeout_minutes: 5
+          max_attempts: 3
+          retry_wait_seconds: 30
+          command: |
+            cd /tmp/digests
+            docker buildx imagetools create $(jq -cr '.tags | map(select(startswith("ghcr.io") | not)) | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
+              $(printf 'ghcr.io/${{ github.repository }}@sha256:%s ' *)
 
       - name: Inspect image in Docker Hub
-        if: vars.DOCKER_HUB_REPO != ''
         run: |
           docker buildx imagetools inspect ${{ vars.DOCKER_HUB_REPO }}:${{ steps.docker.outputs.version }}
 
+  cleanup-digests:
+    name: Cleanup digest artifacts
+    runs-on: ubuntu-latest
+    needs: [push-manifest-ghcr, push-manifest-dockerhub]
+    if: always() && needs.push-manifest-ghcr.result == 'success'
+    steps:
       - name: Delete unnecessary digest artifacts
         env:
           GH_TOKEN: ${{ github.token }}
@@ -316,9 +372,9 @@ jobs:
     runs-on: ubuntu-24.04
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@v7
         with:
           path: ./binaries
           pattern: navidrome-windows*
@@ -337,7 +393,7 @@ jobs:
           du -h binaries/msi/*.msi
 
       - name: Upload MSI files
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: navidrome-windows-installers
           path: binaries/msi/*.msi
@@ -350,12 +406,12 @@ jobs:
     outputs:
       package_list: ${{ steps.set-package-list.outputs.package_list }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
           fetch-tags: true
 
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@v7
         with:
           path: ./binaries
           pattern: navidrome-*
@@ -381,7 +437,7 @@ jobs:
           rm ./dist/*.tar.gz ./dist/*.zip
 
       - name: Upload all-packages artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: packages
           path: dist/navidrome_0*
@@ -404,13 +460,13 @@ jobs:
         item: ${{ fromJson(needs.release.outputs.package_list) }}
     steps:
       - name: Download all-packages artifact
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v7
         with:
           name: packages
           path: ./dist
 
       - name: Upload all-packages artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: navidrome_linux_${{ matrix.item }}
           path: dist/navidrome_0*_linux_${{ matrix.item }}

.github/workflows/stale.yml

@@ -12,7 +12,7 @@ jobs:
       pull-requests: write
     runs-on: ubuntu-latest
     steps:
-      - uses: dessant/lock-threads@v5
+      - uses: dessant/lock-threads@v6
         with:
           process-only: 'issues, prs'
           issue-inactive-days: 120

.github/workflows/update-translations.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ github.repository_owner == 'navidrome' }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Get updated translations
         id: poeditor
         env:
@@ -24,7 +24,7 @@ jobs:
           git status --porcelain
           git diff
       - name: Create Pull Request
-        uses: peter-evans/create-pull-request@v7
+        uses: peter-evans/create-pull-request@v8
         with:
           token: ${{ secrets.PAT }}
           author: "navidrome-bot <navidrome-bot@navidrome.org>"

.github/workflows/validate-translations.sh

@@ -0,0 +1,236 @@
+#!/bin/bash
+
+# validate-translations.sh
+# 
+# This script validates the structure of JSON translation files by comparing them 
+# against the reference English translation file (ui/src/i18n/en.json).
+#
+# The script performs the following validations:
+# 1. JSON syntax validation using jq
+# 2. Structural validation - ensures all keys from English file are present
+# 3. Reports missing keys (translation incomplete)
+# 4. Reports extra keys (keys not in English reference, possibly deprecated)
+# 5. Emits GitHub Actions annotations for CI/CD integration
+#
+# Usage:
+#   ./validate-translations.sh
+#
+# Environment Variables:
+#   EN_FILE          - Path to reference English file (default: ui/src/i18n/en.json)
+#   TRANSLATION_DIR  - Directory containing translation files (default: resources/i18n)
+#
+# Exit codes:
+#   0 - All translations are valid
+#   1 - One or more translations have structural issues
+#
+# GitHub Actions Integration:
+#   The script outputs GitHub Actions annotations using ::error and ::warning
+#   format that will be displayed in PR checks and workflow summaries.
+
+# Script to validate JSON translation files structure against en.json
+set -e
+
+# Path to the reference English translation file
+EN_FILE="${EN_FILE:-ui/src/i18n/en.json}"
+TRANSLATION_DIR="${TRANSLATION_DIR:-resources/i18n}"
+VERBOSE=false
+
+# Parse command line arguments
+while [[ $# -gt 0 ]]; do
+    case "$1" in
+        -v|--verbose)
+            VERBOSE=true
+            shift
+            ;;
+        -h|--help)
+    echo "Usage: $0 [options]"
+    echo ""
+    echo "Validates JSON translation files structure against English reference file."
+    echo ""
+    echo "Options:"
+    echo "  -h, --help     Show this help message"
+    echo "  -v, --verbose  Show detailed output (default: only show errors)"
+    echo ""
+    echo "Environment Variables:"
+    echo "  EN_FILE          Path to reference English file (default: ui/src/i18n/en.json)"
+    echo "  TRANSLATION_DIR  Directory with translation files (default: resources/i18n)"
+    echo ""
+    echo "Examples:"
+    echo "  $0                                    # Validate all translation files (quiet mode)"
+    echo "  $0 -v                                 # Validate with detailed output"
+    echo "  EN_FILE=custom/en.json $0             # Use custom reference file"
+    echo "  TRANSLATION_DIR=custom/i18n $0        # Use custom translations directory"
+    exit 0
+        ;;
+        *)
+            echo "Unknown option: $1" >&2
+            echo "Use --help for usage information" >&2
+            exit 1
+            ;;
+    esac
+done
+
+# Color codes for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+if [[ "$VERBOSE" == "true" ]]; then
+    echo "Validating translation files structure against ${EN_FILE}..."
+fi
+
+# Check if English reference file exists
+if [[ ! -f "$EN_FILE" ]]; then
+    echo "::error::Reference file $EN_FILE not found"
+    exit 1
+fi
+
+# Function to extract all JSON keys from a file, creating a flat list of dot-separated paths
+extract_keys() {
+    local file="$1"
+    jq -r 'paths(scalars) as $p | $p | join(".")' "$file" 2>/dev/null | sort
+}
+
+# Function to extract all non-empty string keys (to identify structural issues)
+extract_structure_keys() {
+    local file="$1"
+    # Get only keys where values are not empty strings
+    jq -r 'paths(scalars) as $p | select(getpath($p) != "") | $p | join(".")' "$file" 2>/dev/null | sort
+}
+
+# Function to validate a single translation file
+validate_translation() {
+    local translation_file="$1"
+    local filename=$(basename "$translation_file")
+    local has_errors=false
+    local verbose=${2:-false}
+    
+    if [[ "$verbose" == "true" ]]; then
+        echo "Validating $filename..."
+    fi
+    
+    # First validate JSON syntax
+    if ! jq empty "$translation_file" 2>/dev/null; then
+        echo "::error file=$translation_file::Invalid JSON syntax"
+        echo -e "${RED}✗ $filename has invalid JSON syntax${NC}"
+        return 1
+    fi
+    
+    # Extract all keys from both files (for statistics)
+    local en_keys_file=$(mktemp)
+    local translation_keys_file=$(mktemp)
+    
+    extract_keys "$EN_FILE" > "$en_keys_file"
+    extract_keys "$translation_file" > "$translation_keys_file"
+    
+    # Extract only non-empty structure keys (to validate structural issues)
+    local en_structure_file=$(mktemp)
+    local translation_structure_file=$(mktemp)
+    
+    extract_structure_keys "$EN_FILE" > "$en_structure_file"
+    extract_structure_keys "$translation_file" > "$translation_structure_file"
+    
+    # Find structural issues: keys in translation not in English (misplaced)
+    local extra_keys=$(comm -13 "$en_keys_file" "$translation_keys_file")
+    
+    # Find missing keys (for statistics only)
+    local missing_keys=$(comm -23 "$en_keys_file" "$translation_keys_file")
+    
+    # Count keys for statistics
+    local total_en_keys=$(wc -l < "$en_keys_file")
+    local total_translation_keys=$(wc -l < "$translation_keys_file") 
+    local missing_count=0
+    local extra_count=0
+    
+    if [[ -n "$missing_keys" ]]; then
+        missing_count=$(echo "$missing_keys" | grep -c '^' || echo 0)
+    fi
+    
+    if [[ -n "$extra_keys" ]]; then
+        extra_count=$(echo "$extra_keys" | grep -c '^' || echo 0)
+        has_errors=true
+    fi
+    
+    # Report extra/misplaced keys (these are structural issues)
+    if [[ -n "$extra_keys" ]]; then
+        if [[ "$verbose" == "true" ]]; then
+            echo -e "${YELLOW}Misplaced keys in $filename ($extra_count):${NC}"
+        fi
+        
+        while IFS= read -r key; do
+            # Try to find the line number
+            line=$(grep -n "\"$(echo "$key" | sed 's/.*\.//')" "$translation_file" | head -1 | cut -d: -f1)
+            line=${line:-1} # Default to line 1 if not found
+            
+            echo "::error file=$translation_file,line=$line::Misplaced key: $key"
+            
+            if [[ "$verbose" == "true" ]]; then
+                echo "  + $key (line ~$line)"
+            fi
+        done <<< "$extra_keys"
+    fi
+    
+    # Clean up temp files
+    rm -f "$en_keys_file" "$translation_keys_file" "$en_structure_file" "$translation_structure_file"
+    
+    # Print statistics
+    if [[ "$verbose" == "true" ]]; then
+        echo "  Keys: $total_translation_keys/$total_en_keys (Missing: $missing_count, Extra/Misplaced: $extra_count)"
+    
+        if [[ "$has_errors" == "true" ]]; then
+            echo -e "${RED}✗ $filename has structural issues${NC}"
+        else
+            echo -e "${GREEN}✓ $filename structure is valid${NC}"
+        fi
+    elif [[ "$has_errors" == "true" ]]; then
+        echo -e "${RED}✗ $filename has structural issues (Extra/Misplaced: $extra_count)${NC}"
+    fi
+    
+    return $([[ "$has_errors" == "true" ]] && echo 1 || echo 0)
+}
+
+# Main validation loop
+validation_failed=false
+total_files=0
+failed_files=0
+valid_files=0
+
+for translation_file in "$TRANSLATION_DIR"/*.json; do
+    if [[ -f "$translation_file" ]]; then
+        total_files=$((total_files + 1))
+        if ! validate_translation "$translation_file" "$VERBOSE"; then
+            validation_failed=true
+            failed_files=$((failed_files + 1))
+        else
+            valid_files=$((valid_files + 1))
+        fi
+        
+        if [[ "$VERBOSE" == "true" ]]; then
+            echo "" # Add spacing between files
+        fi
+    fi
+done
+
+# Summary
+if [[ "$VERBOSE" == "true" ]]; then
+    echo "========================================="
+    echo "Translation Validation Summary:"
+    echo "  Total files: $total_files"
+    echo "  Valid files: $valid_files"
+    echo "  Files with structural issues: $failed_files"
+    echo "========================================="
+fi
+
+if [[ "$validation_failed" == "true" ]]; then
+    if [[ "$VERBOSE" == "true" ]]; then
+        echo -e "${RED}Translation validation failed - $failed_files file(s) have structural issues${NC}"
+    else
+        echo -e "${RED}Translation validation failed - $failed_files/$total_files file(s) have structural issues${NC}"
+    fi
+    exit 1
+elif [[ "$VERBOSE" == "true" ]]; then
+    echo -e "${GREEN}All translation files are structurally valid${NC}"
+fi
+
+exit 0

.gitignore

@@ -5,6 +5,7 @@
 /navidrome
 /iTunes*.xml
 /tmp
+/bin
 data/*
 vendor/*/
 wiki
@@ -16,6 +17,7 @@ master.zip
 testDB
 cache/*
 *.swp
+coverage.out
 dist
 music
 *.db*
@@ -23,7 +25,15 @@ music
 docker-compose.yml
 !contrib/docker-compose.yml
 binaries
-navidrome-master
+navidrome-*
+/ndpgen
 AGENTS.md
+.github/prompts
+.github/instructions
+.github/git-commit-instructions.md
 *.exe
-bin/
+*.test
+*.wasm
+*.ndp
+openspec/
+go.work*

.nvmrc

@@ -1 +1 @@
-v20
+v24

Dockerfile

@@ -1,11 +1,11 @@
 FROM --platform=$BUILDPLATFORM ghcr.io/crazy-max/osxcross:14.5-debian AS osxcross
 
 ########################################################################################################################
-### Build xx (orignal image: tonistiigi/xx)
-FROM --platform=$BUILDPLATFORM public.ecr.aws/docker/library/alpine:3.21 AS xx-build
+### Build xx (original image: tonistiigi/xx)
+FROM --platform=$BUILDPLATFORM public.ecr.aws/docker/library/alpine:3.20 AS xx-build
 
-# v1.5.0
-ENV XX_VERSION=b4e4c451c778822e6742bfc9d9a91d7c7d885c8a
+# v1.9.0
+ENV XX_VERSION=a5592eab7a57895e8d385394ff12241bc65ecd50
 
 RUN apk add -U --no-cache git
 RUN git clone https://github.com/tonistiigi/xx && \
@@ -26,12 +26,14 @@ COPY --from=xx-build /out/ /usr/bin/
 
 ########################################################################################################################
 ### Get TagLib
-FROM --platform=$BUILDPLATFORM public.ecr.aws/docker/library/alpine:3.21 AS taglib-build
+FROM --platform=$BUILDPLATFORM public.ecr.aws/docker/library/alpine:3.20 AS taglib-build
 ARG TARGETPLATFORM
-ARG CROSS_TAGLIB_VERSION=2.0.2-1
+ARG CROSS_TAGLIB_VERSION=2.1.1-2
 ENV CROSS_TAGLIB_RELEASES_URL=https://github.com/navidrome/cross-taglib/releases/download/v${CROSS_TAGLIB_VERSION}/
 
+# wget in busybox can't follow redirects
 RUN <<EOT
+    apk add --no-cache wget
     PLATFORM=$(echo ${TARGETPLATFORM} | tr '/' '-')
     FILE=taglib-${PLATFORM}.tar.gz
 
@@ -61,7 +63,7 @@ COPY --from=ui /build /build
 
 ########################################################################################################################
 ### Build Navidrome binary
-FROM --platform=$BUILDPLATFORM public.ecr.aws/docker/library/golang:1.24-bookworm AS base
+FROM --platform=$BUILDPLATFORM public.ecr.aws/docker/library/golang:1.25-trixie AS base
 RUN apt-get update && apt-get install -y clang lld
 COPY --from=xx / /
 WORKDIR /workspace
@@ -92,6 +94,7 @@ RUN --mount=type=bind,source=. \
     # Setup CGO cross-compilation environment
     xx-go --wrap
     export CGO_ENABLED=1
+    export CGO_CFLAGS_ALLOW="--define-prefix"
     export PKG_CONFIG_PATH=/taglib/lib/pkgconfig
     cat $(go env GOENV)
 
@@ -120,7 +123,7 @@ COPY --from=build /out /
 
 ########################################################################################################################
 ### Build Final Image
-FROM public.ecr.aws/docker/library/alpine:3.21 AS final
+FROM public.ecr.aws/docker/library/alpine:3.20 AS final
 LABEL maintainer="deluan@navidrome.org"
 LABEL org.opencontainers.image.source="https://github.com/navidrome/navidrome"
 
@@ -135,7 +138,6 @@ ENV ND_MUSICFOLDER=/music
 ENV ND_DATAFOLDER=/data
 ENV ND_CONFIGFILE=/data/navidrome.toml
 ENV ND_PORT=4533
-ENV GODEBUG="asyncpreemptoff=1"
 RUN touch /.nddockerenv
 
 EXPOSE ${ND_PORT}

Makefile

@@ -1,6 +1,10 @@
 GO_VERSION=$(shell grep "^go " go.mod | cut -f 2 -d ' ')
 NODE_VERSION=$(shell cat .nvmrc)
 
+# Set global environment variables, required for most targets
+export CGO_CFLAGS_ALLOW=--define-prefix
+export ND_ENABLEINSIGHTSCOLLECTOR=false
+
 ifneq ("$(wildcard .git/HEAD)","")
 GIT_SHA=$(shell git rev-parse --short HEAD)
 GIT_TAG=$(shell git describe --tags `git rev-list --tags --max-count=1`)-SNAPSHOT
@@ -9,13 +13,14 @@ GIT_SHA=source_archive
 GIT_TAG=$(patsubst navidrome-%,v%,$(notdir $(PWD)))-SNAPSHOT
 endif
 
-SUPPORTED_PLATFORMS ?= linux/amd64,linux/arm64,linux/arm/v5,linux/arm/v6,linux/arm/v7,linux/386,darwin/amd64,darwin/arm64,windows/amd64,windows/386
+SUPPORTED_PLATFORMS ?= linux/amd64,linux/arm64,linux/arm/v5,linux/arm/v6,linux/arm/v7,linux/386,linux/riscv64,darwin/amd64,darwin/arm64,windows/amd64,windows/386
 IMAGE_PLATFORMS ?= $(shell echo $(SUPPORTED_PLATFORMS) | tr ',' '\n' | grep "linux" | grep -v "arm/v5" | tr '\n' ',' | sed 's/,$$//')
 PLATFORMS ?= $(SUPPORTED_PLATFORMS)
 DOCKER_TAG ?= deluan/navidrome:develop
 
 # Taglib version to use in cross-compilation, from https://github.com/navidrome/cross-taglib
-CROSS_TAGLIB_VERSION ?= 2.0.2-1
+CROSS_TAGLIB_VERSION ?= 2.1.1-2
+GOLANGCI_LINT_VERSION ?= v2.8.0
 
 UI_SRC_FILES := $(shell find ui -type f -not -path "ui/build/*" -not -path "ui/node_modules/*")
 
@@ -25,36 +30,70 @@ setup: check_env download-deps install-golangci-lint setup-git ##@1_Run_First In
 .PHONY: setup
 
 dev: check_env   ##@Development Start Navidrome in development mode, with hot-reload for both frontend and backend
-	ND_ENABLEINSIGHTSCOLLECTOR="false" npx foreman -j Procfile.dev -p 4533 start
+	npx foreman -j Procfile.dev -p 4533 start
 .PHONY: dev
 
 server: check_go_env buildjs ##@Development Start the backend in development mode
-	@ND_ENABLEINSIGHTSCOLLECTOR="false" go tool reflex -d none -c reflex.conf
+	go tool reflex -d none -c reflex.conf
 .PHONY: server
 
+stop: ##@Development Stop development servers (UI and backend)
+	@echo "Stopping development servers..."
+	@-pkill -f "vite"
+	@-pkill -f "go tool reflex.*reflex.conf"
+	@-pkill -f "go run.*netgo"
+	@echo "Development servers stopped."
+.PHONY: stop
+
 watch: ##@Development Start Go tests in watch mode (re-run when code changes)
 	go tool ginkgo watch -tags=netgo -notify ./...
 .PHONY: watch
 
 PKG ?= ./...
-test: ##@Development Run Go tests
+test: ##@Development Run Go tests. Use PKG variable to specify packages to test, e.g. make test PKG=./server
 	go test -tags netgo $(PKG)
 .PHONY: test
 
-testrace: ##@Development Run Go tests with race detector
-	go test -tags netgo -race -shuffle=on ./...
-.PHONY: test
+test-ndpgen: ##@Development Run tests for ndpgen plugin
+	cd plugins/cmd/ndpgen && go test ./......
+.PHONY: test-ndpgen
 
-testall: testrace ##@Development Run Go and JS tests
-	@(cd ./ui && npm run test)
+testall: test test-ndpgen test-i18n test-js ##@Development Run Go and JS tests
 .PHONY: testall
 
+test-race: ##@Development Run Go tests with race detector
+	go test -tags netgo -race -shuffle=on  $(PKG)
+.PHONY: test-race
+
+test-js: ##@Development Run JS tests
+	@(cd ./ui && npm run test)
+.PHONY: test-js
+
+test-i18n: ##@Development Validate all translations files
+	./.github/workflows/validate-translations.sh 
+.PHONY: test-i18n
+
 install-golangci-lint: ##@Development Install golangci-lint if not present
-	@PATH=$$PATH:./bin which golangci-lint > /dev/null || (echo "Installing golangci-lint..." && curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/HEAD/install.sh | sh -s v2.1.6)
+	@INSTALL=false; \
+	if PATH=$$PATH:./bin which golangci-lint > /dev/null 2>&1; then \
+		CURRENT_VERSION=$$(PATH=$$PATH:./bin golangci-lint version 2>/dev/null | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -n1); \
+		REQUIRED_VERSION=$$(echo "$(GOLANGCI_LINT_VERSION)" | sed 's/^v//'); \
+		if [ "$$CURRENT_VERSION" != "$$REQUIRED_VERSION" ]; then \
+			echo "Found golangci-lint $$CURRENT_VERSION, but $$REQUIRED_VERSION is required. Reinstalling..."; \
+			rm -f ./bin/golangci-lint; \
+			INSTALL=true; \
+		fi; \
+	else \
+		INSTALL=true; \
+	fi; \
+	if [ "$$INSTALL" = "true" ]; then \
+		echo "Installing golangci-lint $(GOLANGCI_LINT_VERSION)..."; \
+		curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/HEAD/install.sh | sh -s $(GOLANGCI_LINT_VERSION); \
+	fi
 .PHONY: install-golangci-lint
 
 lint: install-golangci-lint ##@Development Lint Go code
-	PATH=$$PATH:./bin golangci-lint run -v --timeout 5m
+	PATH=$$PATH:./bin golangci-lint run --timeout 5m
 .PHONY: lint
 
 lintall: lint ##@Development Lint Go and JS code
@@ -64,7 +103,7 @@ lintall: lint ##@Development Lint Go and JS code
 
 format: ##@Development Format code
 	@(cd ./ui && npm run prettier)
-	@go tool goimports -w `find . -name '*.go' | grep -v _gen.go$$`
+	@go tool goimports -w `find . -name '*.go' | grep -v _gen.go$$ | grep -v .pb.go$$`
 	@go mod tidy
 .PHONY: format
 
@@ -72,6 +111,15 @@ wire: check_go_env ##@Development Update Dependency Injection
 	go tool wire gen -tags=netgo ./...
 .PHONY: wire
 
+gen: check_go_env ##@Development Run go generate for code generation
+	go generate ./...
+	cd plugins/cmd/ndpgen && go run . -host-wrappers -input=../../host -package=host
+	cd plugins/cmd/ndpgen && go run . -input=../../host -output=../../pdk -go -python -rust
+	cd plugins/cmd/ndpgen && go run . -capability-only -input=../../capabilities -output=../../pdk -go -rust
+	cd plugins/cmd/ndpgen && go run . -schemas -input=../../capabilities
+	go mod tidy -C plugins/pdk/go
+.PHONY: gen
+
 snapshots: ##@Development Update (GoLang) Snapshot tests
 	UPDATE_SNAPSHOTS=true go tool ginkgo ./server/subsonic/responses/...
 .PHONY: snapshots
@@ -153,6 +201,20 @@ docker-msi: ##@Cross_Compilation Build MSI installer for Windows
 	@du -h binaries/msi/*.msi
 .PHONY: docker-msi
 
+run-docker: ##@Development Run a Navidrome Docker image. Usage: make run-docker tag=<tag>
+	@if [ -z "$(tag)" ]; then echo "Usage: make run-docker tag=<tag>"; exit 1; fi
+	@TAG_DIR="tmp/$$(echo '$(tag)' | tr '/:' '_')"; mkdir -p "$$TAG_DIR"; \
+    VOLUMES="-v $(PWD)/$$TAG_DIR:/data"; \
+	if [ -f navidrome.toml ]; then \
+		VOLUMES="$$VOLUMES -v $(PWD)/navidrome.toml:/data/navidrome.toml:ro"; \
+		MUSIC_FOLDER=$$(grep '^MusicFolder' navidrome.toml | head -n1 | sed 's/.*= *"//' | sed 's/".*//'); \
+		if [ -n "$$MUSIC_FOLDER" ] && [ -d "$$MUSIC_FOLDER" ]; then \
+		  VOLUMES="$$VOLUMES -v $$MUSIC_FOLDER:/music:ro"; \
+	  	fi; \
+	fi; \
+	echo "Running: docker run --rm -p 4533:4533 $$VOLUMES $(tag)"; docker run --rm -p 4533:4533 $$VOLUMES $(tag)
+.PHONY: run-docker
+
 package: docker-build ##@Cross_Compilation Create binaries and packages for ALL supported platforms
 	@if [ -z `which goreleaser` ]; then echo "Please install goreleaser first: https://goreleaser.com/install/"; exit 1; fi
 	goreleaser release -f release/goreleaser.yml --clean --skip=publish --snapshot

adapters/deezer/client.go

@@ -0,0 +1,217 @@
+package deezer
+
+import (
+	bytes "bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/microcosm-cc/bluemonday"
+	"github.com/navidrome/navidrome/log"
+)
+
+const apiBaseURL = "https://api.deezer.com"
+const authBaseURL = "https://auth.deezer.com"
+
+var (
+	ErrNotFound = errors.New("deezer: not found")
+)
+
+type httpDoer interface {
+	Do(req *http.Request) (*http.Response, error)
+}
+
+type client struct {
+	httpDoer httpDoer
+	jwt      jwtToken
+}
+
+func newClient(hc httpDoer) *client {
+	return &client{
+		httpDoer: hc,
+	}
+}
+
+func (c *client) searchArtists(ctx context.Context, name string, limit int) ([]Artist, error) {
+	params := url.Values{}
+	params.Add("q", name)
+	params.Add("order", "RANKING")
+	params.Add("limit", strconv.Itoa(limit))
+	req, err := http.NewRequestWithContext(ctx, "GET", apiBaseURL+"/search/artist", nil)
+	if err != nil {
+		return nil, err
+	}
+	req.URL.RawQuery = params.Encode()
+
+	var results SearchArtistResults
+	err = c.makeRequest(req, &results)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(results.Data) == 0 {
+		return nil, ErrNotFound
+	}
+	return results.Data, nil
+}
+
+func (c *client) makeRequest(req *http.Request, response any) error {
+	log.Trace(req.Context(), fmt.Sprintf("Sending Deezer %s request", req.Method), "url", req.URL)
+	resp, err := c.httpDoer.Do(req)
+	if err != nil {
+		return err
+	}
+
+	defer resp.Body.Close()
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode != 200 {
+		return c.parseError(data)
+	}
+
+	return json.Unmarshal(data, response)
+}
+
+func (c *client) parseError(data []byte) error {
+	var deezerError Error
+	err := json.Unmarshal(data, &deezerError)
+	if err != nil {
+		return err
+	}
+	return fmt.Errorf("deezer error(%d): %s", deezerError.Error.Code, deezerError.Error.Message)
+}
+
+func (c *client) getRelatedArtists(ctx context.Context, artistID int) ([]Artist, error) {
+	req, err := http.NewRequestWithContext(ctx, "GET", fmt.Sprintf("%s/artist/%d/related", apiBaseURL, artistID), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	var results RelatedArtists
+	err = c.makeRequest(req, &results)
+	if err != nil {
+		return nil, err
+	}
+
+	return results.Data, nil
+}
+
+func (c *client) getTopTracks(ctx context.Context, artistID int, limit int) ([]Track, error) {
+	params := url.Values{}
+	params.Add("limit", strconv.Itoa(limit))
+	req, err := http.NewRequestWithContext(ctx, "GET", fmt.Sprintf("%s/artist/%d/top", apiBaseURL, artistID), nil)
+	if err != nil {
+		return nil, err
+	}
+	req.URL.RawQuery = params.Encode()
+
+	var results TopTracks
+	err = c.makeRequest(req, &results)
+	if err != nil {
+		return nil, err
+	}
+
+	return results.Data, nil
+}
+
+const pipeAPIURL = "https://pipe.deezer.com/api"
+
+var strictPolicy = bluemonday.StrictPolicy()
+
+func (c *client) getArtistBio(ctx context.Context, artistID int, lang string) (string, error) {
+	jwt, err := c.getJWT(ctx)
+	if err != nil {
+		return "", fmt.Errorf("deezer: failed to get JWT: %w", err)
+	}
+
+	query := map[string]any{
+		"operationName": "ArtistBio",
+		"variables": map[string]any{
+			"artistId": strconv.Itoa(artistID),
+		},
+		"query": `query ArtistBio($artistId: String!) {
+			artist(artistId: $artistId) {
+				bio {
+					full
+				}
+			}
+		}`,
+	}
+
+	body, err := json.Marshal(query)
+	if err != nil {
+		return "", err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "POST", pipeAPIURL, bytes.NewReader(body))
+	if err != nil {
+		return "", err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept-Language", lang)
+	req.Header.Set("Authorization", "Bearer "+jwt)
+
+	log.Trace(ctx, "Fetching Deezer artist biography via GraphQL", "artistId", artistID, "language", lang)
+	resp, err := c.httpDoer.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return "", fmt.Errorf("deezer: failed to fetch biography: %s", resp.Status)
+	}
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	type graphQLResponse struct {
+		Data struct {
+			Artist struct {
+				Bio struct {
+					Full string `json:"full"`
+				} `json:"bio"`
+			} `json:"artist"`
+		} `json:"data"`
+		Errors []struct {
+			Message string `json:"message"`
+		}
+	}
+
+	var result graphQLResponse
+	if err := json.Unmarshal(data, &result); err != nil {
+		return "", fmt.Errorf("deezer: failed to parse GraphQL response: %w", err)
+	}
+
+	if len(result.Errors) > 0 {
+		var errs []error
+		for m := range result.Errors {
+			errs = append(errs, errors.New(result.Errors[m].Message))
+		}
+		err := errors.Join(errs...)
+		return "", fmt.Errorf("deezer: GraphQL error: %w", err)
+	}
+
+	if result.Data.Artist.Bio.Full == "" {
+		return "", errors.New("deezer: biography not found")
+	}
+
+	return cleanBio(result.Data.Artist.Bio.Full), nil
+}
+
+func cleanBio(bio string) string {
+	bio = strings.ReplaceAll(bio, "</p>", "\n")
+	return strictPolicy.Sanitize(bio)
+}

adapters/deezer/client_auth.go

@@ -0,0 +1,101 @@
+package deezer
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/lestrrat-go/jwx/v2/jwt"
+	"github.com/navidrome/navidrome/log"
+)
+
+type jwtToken struct {
+	token     string
+	expiresAt time.Time
+	mu        sync.RWMutex
+}
+
+func (j *jwtToken) get() (string, bool) {
+	j.mu.RLock()
+	defer j.mu.RUnlock()
+	if time.Now().Before(j.expiresAt) {
+		return j.token, true
+	}
+	return "", false
+}
+
+func (j *jwtToken) set(token string, expiresIn time.Duration) {
+	j.mu.Lock()
+	defer j.mu.Unlock()
+	j.token = token
+	j.expiresAt = time.Now().Add(expiresIn)
+}
+
+func (c *client) getJWT(ctx context.Context) (string, error) {
+	// Check if we have a valid cached token
+	if token, valid := c.jwt.get(); valid {
+		return token, nil
+	}
+
+	// Fetch a new anonymous token
+	req, err := http.NewRequestWithContext(ctx, "GET", authBaseURL+"/login/anonymous?jo=p&rto=c", nil)
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := c.httpDoer.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return "", fmt.Errorf("deezer: failed to get JWT token: %s", resp.Status)
+	}
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	type authResponse struct {
+		JWT string `json:"jwt"`
+	}
+
+	var result authResponse
+	if err := json.Unmarshal(data, &result); err != nil {
+		return "", fmt.Errorf("deezer: failed to parse auth response: %w", err)
+	}
+
+	if result.JWT == "" {
+		return "", errors.New("deezer: no JWT token in response")
+	}
+
+	// Parse JWT to get actual expiration time
+	token, err := jwt.ParseString(result.JWT, jwt.WithVerify(false), jwt.WithValidate(false))
+	if err != nil {
+		return "", fmt.Errorf("deezer: failed to parse JWT token: %w", err)
+	}
+
+	// Calculate TTL with a 1-minute buffer for clock skew and network delays
+	expiresAt := token.Expiration()
+	if expiresAt.IsZero() {
+		return "", errors.New("deezer: JWT token has no expiration time")
+	}
+
+	ttl := time.Until(expiresAt) - 1*time.Minute
+	if ttl <= 0 {
+		return "", errors.New("deezer: JWT token already expired or expires too soon")
+	}
+
+	c.jwt.set(result.JWT, ttl)
+	log.Trace(ctx, "Fetched new Deezer JWT token", "expiresAt", expiresAt, "ttl", ttl)
+
+	return result.JWT, nil
+}

adapters/deezer/client_auth_test.go

@@ -0,0 +1,293 @@
+package deezer
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/lestrrat-go/jwx/v2/jwt"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("JWT Authentication", func() {
+	var httpClient *fakeHttpClient
+	var client *client
+	var ctx context.Context
+
+	BeforeEach(func() {
+		httpClient = &fakeHttpClient{}
+		client = newClient(httpClient)
+		ctx = context.Background()
+	})
+
+	Describe("getJWT", func() {
+		Context("with a valid JWT response", func() {
+			It("successfully fetches and caches a JWT token", func() {
+				testJWT := createTestJWT(5 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, testJWT))),
+				})
+
+				token, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token).To(Equal(testJWT))
+			})
+
+			It("returns the cached token on subsequent calls", func() {
+				testJWT := createTestJWT(5 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, testJWT))),
+				})
+
+				// First call should fetch from API
+				token1, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token1).To(Equal(testJWT))
+				Expect(httpClient.lastRequest.URL.Path).To(Equal("/login/anonymous"))
+
+				// Second call should return cached token without hitting API
+				httpClient.lastRequest = nil // Clear last request to verify no new request is made
+				token2, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token2).To(Equal(testJWT))
+				Expect(httpClient.lastRequest).To(BeNil()) // No new request made
+			})
+
+			It("parses the JWT expiration time correctly", func() {
+				expectedExpiration := time.Now().Add(5 * time.Minute)
+				testToken, err := jwt.NewBuilder().
+					Expiration(expectedExpiration).
+					Build()
+				Expect(err).To(BeNil())
+				testJWT, err := jwt.Sign(testToken, jwt.WithInsecureNoSignature())
+				Expect(err).To(BeNil())
+
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, string(testJWT)))),
+				})
+
+				token, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token).ToNot(BeEmpty())
+
+				// Verify the token is cached until close to expiration
+				// The cache should expire 1 minute before the JWT expires
+				expectedCacheExpiry := expectedExpiration.Add(-1 * time.Minute)
+				Expect(client.jwt.expiresAt).To(BeTemporally("~", expectedCacheExpiry, 2*time.Second))
+			})
+		})
+
+		Context("with JWT tokens that expire soon", func() {
+			It("rejects tokens that expire in less than 1 minute", func() {
+				// Create a token that expires in 30 seconds (less than 1-minute buffer)
+				testJWT := createTestJWT(30 * time.Second)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, testJWT))),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("JWT token already expired or expires too soon"))
+			})
+
+			It("rejects already expired tokens", func() {
+				// Create a token that expired 1 minute ago
+				testJWT := createTestJWT(-1 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, testJWT))),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("JWT token already expired or expires too soon"))
+			})
+
+			It("accepts tokens that expire in more than 1 minute", func() {
+				// Create a token that expires in 2 minutes (just over the 1-minute buffer)
+				testJWT := createTestJWT(2 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, testJWT))),
+				})
+
+				token, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token).ToNot(BeEmpty())
+			})
+		})
+
+		Context("with invalid responses", func() {
+			It("handles HTTP error responses", func() {
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 500,
+					Body:       io.NopCloser(bytes.NewBufferString(`{"error":"Internal server error"}`)),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("failed to get JWT token"))
+			})
+
+			It("handles malformed JSON responses", func() {
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(`{invalid json}`)),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("failed to parse auth response"))
+			})
+
+			It("handles responses with empty JWT field", func() {
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(`{"jwt":""}`)),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(Equal("deezer: no JWT token in response"))
+			})
+
+			It("handles invalid JWT tokens", func() {
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(`{"jwt":"not-a-valid-jwt"}`)),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("failed to parse JWT token"))
+			})
+
+			It("rejects JWT tokens without expiration", func() {
+				// Create a JWT without expiration claim
+				testToken, err := jwt.NewBuilder().
+					Claim("custom", "value").
+					Build()
+				Expect(err).To(BeNil())
+
+				// Verify token has no expiration
+				Expect(testToken.Expiration().IsZero()).To(BeTrue())
+
+				testJWT, err := jwt.Sign(testToken, jwt.WithInsecureNoSignature())
+				Expect(err).To(BeNil())
+
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, string(testJWT)))),
+				})
+
+				_, err = client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(Equal("deezer: JWT token has no expiration time"))
+			})
+		})
+
+		Context("token caching behavior", func() {
+			It("fetches a new token when the cached token expires", func() {
+				// First token expires in 5 minutes
+				firstJWT := createTestJWT(5 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, firstJWT))),
+				})
+
+				token1, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token1).To(Equal(firstJWT))
+
+				// Manually expire the cached token
+				client.jwt.expiresAt = time.Now().Add(-1 * time.Second)
+
+				// Second token with different expiration (10 minutes)
+				secondJWT := createTestJWT(10 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, secondJWT))),
+				})
+
+				token2, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token2).To(Equal(secondJWT))
+				Expect(token2).ToNot(Equal(token1))
+			})
+		})
+	})
+
+	Describe("jwtToken cache", func() {
+		var cache *jwtToken
+
+		BeforeEach(func() {
+			cache = &jwtToken{}
+		})
+
+		It("returns false for expired tokens", func() {
+			cache.set("test-token", -1*time.Second) // Already expired
+			token, valid := cache.get()
+			Expect(valid).To(BeFalse())
+			Expect(token).To(BeEmpty())
+		})
+
+		It("returns true for valid tokens", func() {
+			cache.set("test-token", 4*time.Minute)
+			token, valid := cache.get()
+			Expect(valid).To(BeTrue())
+			Expect(token).To(Equal("test-token"))
+		})
+
+		It("is thread-safe for concurrent access", func() {
+			wg := sync.WaitGroup{}
+
+			// Writer goroutine
+			wg.Go(func() {
+				for i := 0; i < 100; i++ {
+					cache.set(fmt.Sprintf("token-%d", i), 1*time.Hour)
+					time.Sleep(1 * time.Millisecond)
+				}
+			})
+
+			// Reader goroutine
+			wg.Go(func() {
+				for i := 0; i < 100; i++ {
+					cache.get()
+					time.Sleep(1 * time.Millisecond)
+				}
+			})
+
+			// Wait for both goroutines to complete
+			wg.Wait()
+
+			// Verify final state is valid
+			token, valid := cache.get()
+			Expect(valid).To(BeTrue())
+			Expect(token).To(HavePrefix("token-"))
+		})
+	})
+})
+
+// createTestJWT creates a valid JWT token for testing purposes
+func createTestJWT(expiresIn time.Duration) string {
+	token, err := jwt.NewBuilder().
+		Expiration(time.Now().Add(expiresIn)).
+		Build()
+	if err != nil {
+		panic(fmt.Sprintf("failed to create test JWT: %v", err))
+	}
+	signed, err := jwt.Sign(token, jwt.WithInsecureNoSignature())
+	if err != nil {
+		panic(fmt.Sprintf("failed to sign test JWT: %v", err))
+	}
+	return string(signed)
+}

adapters/deezer/client_test.go

@@ -0,0 +1,210 @@
+package deezer
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"time"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("client", func() {
+	var httpClient *fakeHttpClient
+	var client *client
+
+	BeforeEach(func() {
+		httpClient = &fakeHttpClient{}
+		client = newClient(httpClient)
+	})
+
+	Describe("ArtistImages", func() {
+		It("returns artist images from a successful request", func() {
+			f, err := os.Open("tests/fixtures/deezer.search.artist.json")
+			Expect(err).To(BeNil())
+			httpClient.mock("https://api.deezer.com/search/artist", http.Response{Body: f, StatusCode: 200})
+
+			artists, err := client.searchArtists(GinkgoT().Context(), "Michael Jackson", 20)
+			Expect(err).To(BeNil())
+			Expect(artists).To(HaveLen(17))
+			Expect(artists[0].Name).To(Equal("Michael Jackson"))
+			Expect(artists[0].PictureXl).To(Equal("https://cdn-images.dzcdn.net/images/artist/97fae13b2b30e4aec2e8c9e0c7839d92/1000x1000-000000-80-0-0.jpg"))
+		})
+
+		It("fails if artist was not found", func() {
+			httpClient.mock("https://api.deezer.com/search/artist", http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(`{"data":[],"total":0}`)),
+			})
+
+			_, err := client.searchArtists(GinkgoT().Context(), "Michael Jackson", 20)
+			Expect(err).To(MatchError(ErrNotFound))
+		})
+	})
+
+	Describe("TopTracks", func() {
+		It("returns top tracks with artist and album info from a successful request", func() {
+			f, err := os.Open("tests/fixtures/deezer.artist.top.json")
+			Expect(err).To(BeNil())
+			httpClient.mock("https://api.deezer.com/artist/27/top", http.Response{Body: f, StatusCode: 200})
+
+			tracks, err := client.getTopTracks(GinkgoT().Context(), 27, 5)
+			Expect(err).To(BeNil())
+			Expect(tracks).To(HaveLen(5))
+
+			// Verify first track has all expected fields
+			Expect(tracks[0].Title).To(Equal("Instant Crush (feat. Julian Casablancas)"))
+			Expect(tracks[0].Artist.Name).To(Equal("Daft Punk"))
+			Expect(tracks[0].Album.Title).To(Equal("Random Access Memories"))
+
+			// Verify second track
+			Expect(tracks[1].Title).To(Equal("One More Time"))
+			Expect(tracks[1].Artist.Name).To(Equal("Daft Punk"))
+			Expect(tracks[1].Album.Title).To(Equal("Discovery"))
+		})
+	})
+
+	Describe("ArtistBio", func() {
+		BeforeEach(func() {
+			// Mock the JWT token endpoint with a valid JWT that expires in 5 minutes
+			testJWT := createTestJWT(5 * time.Minute)
+			httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s","refresh_token":""}`, testJWT))),
+			})
+		})
+
+		It("returns artist bio from a successful request", func() {
+			f, err := os.Open("tests/fixtures/deezer.artist.bio.en.json")
+			Expect(err).To(BeNil())
+			httpClient.mock("https://pipe.deezer.com/api", http.Response{Body: f, StatusCode: 200})
+
+			bio, err := client.getArtistBio(GinkgoT().Context(), 27, "en")
+			Expect(err).To(BeNil())
+			Expect(bio).To(ContainSubstring("Schoolmates Thomas and Guy-Manuel"))
+			Expect(bio).ToNot(ContainSubstring("<p>"))
+			Expect(bio).ToNot(ContainSubstring("</p>"))
+		})
+
+		It("uses the provided language", func() {
+			f, err := os.Open("tests/fixtures/deezer.artist.bio.fr.json")
+			Expect(err).To(BeNil())
+			httpClient.mock("https://pipe.deezer.com/api", http.Response{Body: f, StatusCode: 200})
+
+			_, err = client.getArtistBio(GinkgoT().Context(), 27, "fr")
+			Expect(err).To(BeNil())
+			Expect(httpClient.lastRequest.Header.Get("Accept-Language")).To(Equal("fr"))
+		})
+
+		It("includes the JWT token in the request", func() {
+			f, err := os.Open("tests/fixtures/deezer.artist.bio.en.json")
+			Expect(err).To(BeNil())
+			httpClient.mock("https://pipe.deezer.com/api", http.Response{Body: f, StatusCode: 200})
+
+			_, err = client.getArtistBio(GinkgoT().Context(), 27, "en")
+			Expect(err).To(BeNil())
+			// Verify that the Authorization header has the Bearer token format
+			authHeader := httpClient.lastRequest.Header.Get("Authorization")
+			Expect(authHeader).To(HavePrefix("Bearer "))
+			Expect(len(authHeader)).To(BeNumerically(">", 20)) // JWT tokens are longer than 20 chars
+		})
+
+		It("handles GraphQL errors", func() {
+			errorResponse := `{
+				"data": {
+					"artist": {
+						"bio": {
+							"full": ""
+						}
+					}
+				},
+				"errors": [
+					{
+						"message": "Artist not found"
+					},
+					{
+						"message": "Invalid artist ID"
+					}
+				]
+			}`
+			httpClient.mock("https://pipe.deezer.com/api", http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(errorResponse)),
+			})
+
+			_, err := client.getArtistBio(GinkgoT().Context(), 999, "en")
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("GraphQL error"))
+			Expect(err.Error()).To(ContainSubstring("Artist not found"))
+			Expect(err.Error()).To(ContainSubstring("Invalid artist ID"))
+		})
+
+		It("handles empty biography", func() {
+			emptyBioResponse := `{
+				"data": {
+					"artist": {
+						"bio": {
+							"full": ""
+						}
+					}
+				}
+			}`
+			httpClient.mock("https://pipe.deezer.com/api", http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(emptyBioResponse)),
+			})
+
+			_, err := client.getArtistBio(GinkgoT().Context(), 27, "en")
+			Expect(err).To(MatchError("deezer: biography not found"))
+		})
+
+		It("handles JWT token fetch failure", func() {
+			httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+				StatusCode: 500,
+				Body:       io.NopCloser(bytes.NewBufferString(`{"error":"Internal server error"}`)),
+			})
+
+			_, err := client.getArtistBio(GinkgoT().Context(), 27, "en")
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("failed to get JWT"))
+		})
+
+		It("handles JWT token that expires too soon", func() {
+			// Create a JWT that expires in 30 seconds (less than the 1-minute buffer)
+			expiredJWT := createTestJWT(30 * time.Second)
+			httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s","refresh_token":""}`, expiredJWT))),
+			})
+
+			_, err := client.getArtistBio(GinkgoT().Context(), 27, "en")
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("JWT token already expired or expires too soon"))
+		})
+	})
+})
+
+type fakeHttpClient struct {
+	responses   map[string]*http.Response
+	lastRequest *http.Request
+}
+
+func (c *fakeHttpClient) mock(url string, response http.Response) {
+	if c.responses == nil {
+		c.responses = make(map[string]*http.Response)
+	}
+	c.responses[url] = &response
+}
+
+func (c *fakeHttpClient) Do(req *http.Request) (*http.Response, error) {
+	c.lastRequest = req
+	u := req.URL
+	u.RawQuery = ""
+	if resp, ok := c.responses[u.String()]; ok {
+		return resp, nil
+	}
+	panic("URL not mocked: " + u.String())
+}

adapters/deezer/deezer.go

@@ -0,0 +1,172 @@
+package deezer
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils/cache"
+	"github.com/navidrome/navidrome/utils/slice"
+)
+
+const deezerAgentName = "deezer"
+const deezerApiPictureXlSize = 1000
+const deezerApiPictureBigSize = 500
+const deezerApiPictureMediumSize = 250
+const deezerApiPictureSmallSize = 56
+const deezerArtistSearchLimit = 50
+
+type deezerAgent struct {
+	dataStore model.DataStore
+	client    *client
+	languages []string
+}
+
+func deezerConstructor(dataStore model.DataStore) agents.Interface {
+	agent := &deezerAgent{
+		dataStore: dataStore,
+		languages: conf.Server.Deezer.Languages,
+	}
+	httpClient := &http.Client{
+		Timeout: consts.DefaultHttpClientTimeOut,
+	}
+	cachedHttpClient := cache.NewHTTPClient(httpClient, consts.DefaultHttpClientTimeOut)
+	agent.client = newClient(cachedHttpClient)
+	return agent
+}
+
+func (s *deezerAgent) AgentName() string {
+	return deezerAgentName
+}
+
+func (s *deezerAgent) GetArtistImages(ctx context.Context, _, name, _ string) ([]agents.ExternalImage, error) {
+	artist, err := s.searchArtist(ctx, name)
+	if err != nil {
+		if errors.Is(err, agents.ErrNotFound) {
+			log.Warn(ctx, "Artist not found in deezer", "artist", name)
+		} else {
+			log.Error(ctx, "Error calling deezer", "artist", name, err)
+		}
+		return nil, err
+	}
+
+	var res []agents.ExternalImage
+	possibleImages := []struct {
+		URL  string
+		Size int
+	}{
+		{artist.PictureXl, deezerApiPictureXlSize},
+		{artist.PictureBig, deezerApiPictureBigSize},
+		{artist.PictureMedium, deezerApiPictureMediumSize},
+		{artist.PictureSmall, deezerApiPictureSmallSize},
+	}
+	for _, imgData := range possibleImages {
+		if imgData.URL != "" {
+			res = append(res, agents.ExternalImage{
+				URL:  imgData.URL,
+				Size: imgData.Size,
+			})
+		}
+	}
+	return res, nil
+}
+
+func (s *deezerAgent) searchArtist(ctx context.Context, name string) (*Artist, error) {
+	artists, err := s.client.searchArtists(ctx, name, deezerArtistSearchLimit)
+	if errors.Is(err, ErrNotFound) || len(artists) == 0 {
+		return nil, agents.ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	log.Trace(ctx, "Artists found", "count", len(artists), "searched_name", name)
+	for i := range artists {
+		log.Trace(ctx, fmt.Sprintf("Artists found #%d", i), "name", artists[i].Name, "id", artists[i].ID, "link", artists[i].Link)
+		if i > 2 {
+			break
+		}
+	}
+
+	// If the first one has the same name, that's the one
+	if !strings.EqualFold(artists[0].Name, name) {
+		log.Trace(ctx, "Top artist do not match", "searched_name", name, "found_name", artists[0].Name)
+		return nil, agents.ErrNotFound
+	}
+	log.Trace(ctx, "Found artist", "name", artists[0].Name, "id", artists[0].ID, "link", artists[0].Link)
+	return &artists[0], err
+}
+
+func (s *deezerAgent) GetSimilarArtists(ctx context.Context, _, name, _ string, limit int) ([]agents.Artist, error) {
+	artist, err := s.searchArtist(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+
+	related, err := s.client.getRelatedArtists(ctx, artist.ID)
+	if err != nil {
+		return nil, err
+	}
+
+	res := slice.Map(related, func(r Artist) agents.Artist {
+		return agents.Artist{
+			Name: r.Name,
+		}
+	})
+	if len(res) > limit {
+		res = res[:limit]
+	}
+	return res, nil
+}
+
+func (s *deezerAgent) GetArtistTopSongs(ctx context.Context, _, artistName, _ string, count int) ([]agents.Song, error) {
+	artist, err := s.searchArtist(ctx, artistName)
+	if err != nil {
+		return nil, err
+	}
+
+	tracks, err := s.client.getTopTracks(ctx, artist.ID, count)
+	if err != nil {
+		return nil, err
+	}
+
+	res := slice.Map(tracks, func(r Track) agents.Song {
+		return agents.Song{
+			Name:     r.Title,
+			Album:    r.Album.Title,
+			Duration: uint32(r.Duration * 1000), // Convert seconds to milliseconds
+		}
+	})
+	return res, nil
+}
+
+func (s *deezerAgent) GetArtistBiography(ctx context.Context, _, name, _ string) (string, error) {
+	artist, err := s.searchArtist(ctx, name)
+	if err != nil {
+		return "", err
+	}
+
+	for _, lang := range s.languages {
+		bio, err := s.client.getArtistBio(ctx, artist.ID, lang)
+		if err == nil && bio != "" {
+			return bio, nil
+		}
+		log.Debug(ctx, "Deezer/artist.bio returned empty/error, trying next language", "artist", name, "lang", lang, err)
+	}
+	return "", agents.ErrNotFound
+}
+
+func init() {
+	conf.AddHook(func() {
+		if conf.Server.Deezer.Enabled {
+			agents.Register(deezerAgentName, deezerConstructor)
+		}
+	})
+}

adapters/deezer/deezer_suite_test.go

@@ -0,0 +1,17 @@
+package deezer
+
+import (
+	"testing"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestDeezer(t *testing.T) {
+	tests.Init(t, false)
+	log.SetLevel(log.LevelFatal)
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Deezer Test Suite")
+}

adapters/deezer/deezer_test.go

@@ -0,0 +1,171 @@
+package deezer
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("deezerAgent", func() {
+	var ctx context.Context
+
+	BeforeEach(func() {
+		ctx = context.Background()
+		DeferCleanup(configtest.SetupConfig())
+		conf.Server.Deezer.Enabled = true
+	})
+
+	Describe("deezerConstructor", func() {
+		It("uses configured languages", func() {
+			conf.Server.Deezer.Languages = []string{"pt", "en"}
+			agent := deezerConstructor(&tests.MockDataStore{}).(*deezerAgent)
+			Expect(agent.languages).To(Equal([]string{"pt", "en"}))
+		})
+	})
+
+	Describe("GetArtistBiography - Language Fallback", func() {
+		var agent *deezerAgent
+		var httpClient *langAwareHttpClient
+
+		BeforeEach(func() {
+			httpClient = newLangAwareHttpClient()
+
+			// Mock search artist (returns Michael Jackson)
+			fSearch, _ := os.Open("tests/fixtures/deezer.search.artist.json")
+			httpClient.searchResponse = &http.Response{Body: fSearch, StatusCode: 200}
+
+			// Mock JWT token
+			testJWT := createTestJWT(5 * time.Minute)
+			httpClient.jwtResponse = &http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s","refresh_token":""}`, testJWT))),
+			}
+		})
+
+		setupAgent := func(languages []string) {
+			conf.Server.Deezer.Languages = languages
+			agent = &deezerAgent{
+				dataStore: &tests.MockDataStore{},
+				client:    newClient(httpClient),
+				languages: languages,
+			}
+		}
+
+		It("returns content in first language when available (1 bio API call)", func() {
+			setupAgent([]string{"fr", "en"})
+
+			// French biography available
+			fFr, _ := os.Open("tests/fixtures/deezer.artist.bio.fr.json")
+			httpClient.bioResponses["fr"] = &http.Response{Body: fFr, StatusCode: 200}
+
+			bio, err := agent.GetArtistBiography(ctx, "", "Michael Jackson", "")
+
+			Expect(err).ToNot(HaveOccurred())
+			Expect(bio).To(ContainSubstring("Guy-Manuel de Homem Christo et Thomas Bangalter"))
+			Expect(httpClient.bioRequestCount).To(Equal(1))
+			Expect(httpClient.bioRequests[0].Header.Get("Accept-Language")).To(Equal("fr"))
+		})
+
+		It("falls back to second language when first returns empty (2 bio API calls)", func() {
+			setupAgent([]string{"ja", "en"})
+
+			// Japanese returns empty biography
+			fJa, _ := os.Open("tests/fixtures/deezer.artist.bio.empty.json")
+			httpClient.bioResponses["ja"] = &http.Response{Body: fJa, StatusCode: 200}
+			// English returns full biography
+			fEn, _ := os.Open("tests/fixtures/deezer.artist.bio.en.json")
+			httpClient.bioResponses["en"] = &http.Response{Body: fEn, StatusCode: 200}
+
+			bio, err := agent.GetArtistBiography(ctx, "", "Michael Jackson", "")
+
+			Expect(err).ToNot(HaveOccurred())
+			Expect(bio).To(ContainSubstring("Schoolmates Thomas and Guy-Manuel"))
+			Expect(httpClient.bioRequestCount).To(Equal(2))
+			Expect(httpClient.bioRequests[0].Header.Get("Accept-Language")).To(Equal("ja"))
+			Expect(httpClient.bioRequests[1].Header.Get("Accept-Language")).To(Equal("en"))
+		})
+
+		It("returns ErrNotFound when all languages return empty", func() {
+			setupAgent([]string{"ja", "xx"})
+
+			// Both languages return empty biography
+			fJa, _ := os.Open("tests/fixtures/deezer.artist.bio.empty.json")
+			httpClient.bioResponses["ja"] = &http.Response{Body: fJa, StatusCode: 200}
+			fXx, _ := os.Open("tests/fixtures/deezer.artist.bio.empty.json")
+			httpClient.bioResponses["xx"] = &http.Response{Body: fXx, StatusCode: 200}
+
+			_, err := agent.GetArtistBiography(ctx, "", "Michael Jackson", "")
+
+			Expect(err).To(MatchError(agents.ErrNotFound))
+			Expect(httpClient.bioRequestCount).To(Equal(2))
+		})
+	})
+})
+
+// langAwareHttpClient is a mock HTTP client that returns different responses based on the Accept-Language header
+type langAwareHttpClient struct {
+	searchResponse  *http.Response
+	jwtResponse     *http.Response
+	bioResponses    map[string]*http.Response
+	bioRequests     []*http.Request
+	bioRequestCount int
+}
+
+func newLangAwareHttpClient() *langAwareHttpClient {
+	return &langAwareHttpClient{
+		bioResponses: make(map[string]*http.Response),
+		bioRequests:  make([]*http.Request, 0),
+	}
+}
+
+func (c *langAwareHttpClient) Do(req *http.Request) (*http.Response, error) {
+	// Handle search artist request
+	if req.URL.Host == "api.deezer.com" && req.URL.Path == "/search/artist" {
+		if c.searchResponse != nil {
+			return c.searchResponse, nil
+		}
+		return &http.Response{
+			StatusCode: 200,
+			Body:       io.NopCloser(bytes.NewBufferString(`{"data":[],"total":0}`)),
+		}, nil
+	}
+
+	// Handle JWT token request
+	if req.URL.Host == "auth.deezer.com" && req.URL.Path == "/login/anonymous" {
+		if c.jwtResponse != nil {
+			return c.jwtResponse, nil
+		}
+		return &http.Response{
+			StatusCode: 500,
+			Body:       io.NopCloser(bytes.NewBufferString(`{"error":"no mock"}`)),
+		}, nil
+	}
+
+	// Handle bio request (GraphQL API)
+	if req.URL.Host == "pipe.deezer.com" && req.URL.Path == "/api" {
+		c.bioRequestCount++
+		c.bioRequests = append(c.bioRequests, req)
+		lang := req.Header.Get("Accept-Language")
+		if resp, ok := c.bioResponses[lang]; ok {
+			return resp, nil
+		}
+		// Return empty bio by default
+		return &http.Response{
+			StatusCode: 200,
+			Body:       io.NopCloser(bytes.NewBufferString(`{"data":{"artist":{"bio":{"full":""}}}}`)),
+		}, nil
+	}
+
+	panic("URL not mocked: " + req.URL.String())
+}

adapters/deezer/responses.go

@@ -0,0 +1,66 @@
+package deezer
+
+type SearchArtistResults struct {
+	Data  []Artist `json:"data"`
+	Total int      `json:"total"`
+	Next  string   `json:"next"`
+}
+
+type Artist struct {
+	ID            int    `json:"id"`
+	Name          string `json:"name"`
+	Link          string `json:"link"`
+	Picture       string `json:"picture"`
+	PictureSmall  string `json:"picture_small"`
+	PictureMedium string `json:"picture_medium"`
+	PictureBig    string `json:"picture_big"`
+	PictureXl     string `json:"picture_xl"`
+	NbAlbum       int    `json:"nb_album"`
+	NbFan         int    `json:"nb_fan"`
+	Radio         bool   `json:"radio"`
+	Tracklist     string `json:"tracklist"`
+	Type          string `json:"type"`
+}
+
+type Error struct {
+	Error struct {
+		Type    string `json:"type"`
+		Message string `json:"message"`
+		Code    int    `json:"code"`
+	} `json:"error"`
+}
+
+type RelatedArtists struct {
+	Data  []Artist `json:"data"`
+	Total int      `json:"total"`
+}
+
+type TopTracks struct {
+	Data  []Track `json:"data"`
+	Total int     `json:"total"`
+	Next  string  `json:"next"`
+}
+
+type Track struct {
+	ID           int      `json:"id"`
+	Title        string   `json:"title"`
+	Link         string   `json:"link"`
+	Duration     int      `json:"duration"`
+	Rank         int      `json:"rank"`
+	Preview      string   `json:"preview"`
+	Artist       Artist   `json:"artist"`
+	Album        Album    `json:"album"`
+	Contributors []Artist `json:"contributors"`
+}
+
+type Album struct {
+	ID          int    `json:"id"`
+	Title       string `json:"title"`
+	Cover       string `json:"cover"`
+	CoverSmall  string `json:"cover_small"`
+	CoverMedium string `json:"cover_medium"`
+	CoverBig    string `json:"cover_big"`
+	CoverXl     string `json:"cover_xl"`
+	Tracklist   string `json:"tracklist"`
+	Type        string `json:"type"`
+}

adapters/deezer/responses_test.go

@@ -0,0 +1,69 @@
+package deezer
+
+import (
+	"encoding/json"
+	"os"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Responses", func() {
+	Describe("Search type=artist", func() {
+		It("parses the artist search result correctly ", func() {
+			var resp SearchArtistResults
+			body, err := os.ReadFile("tests/fixtures/deezer.search.artist.json")
+			Expect(err).To(BeNil())
+			err = json.Unmarshal(body, &resp)
+			Expect(err).To(BeNil())
+
+			Expect(resp.Data).To(HaveLen(17))
+			michael := resp.Data[0]
+			Expect(michael.Name).To(Equal("Michael Jackson"))
+			Expect(michael.PictureXl).To(Equal("https://cdn-images.dzcdn.net/images/artist/97fae13b2b30e4aec2e8c9e0c7839d92/1000x1000-000000-80-0-0.jpg"))
+		})
+	})
+
+	Describe("Error", func() {
+		It("parses the error response correctly", func() {
+			var errorResp Error
+			body := []byte(`{"error":{"type":"MissingParameterException","message":"Missing parameters: q","code":501}}`)
+			err := json.Unmarshal(body, &errorResp)
+			Expect(err).To(BeNil())
+
+			Expect(errorResp.Error.Code).To(Equal(501))
+			Expect(errorResp.Error.Message).To(Equal("Missing parameters: q"))
+		})
+	})
+
+	Describe("Related Artists", func() {
+		It("parses the related artists response correctly", func() {
+			var resp RelatedArtists
+			body, err := os.ReadFile("tests/fixtures/deezer.artist.related.json")
+			Expect(err).To(BeNil())
+			err = json.Unmarshal(body, &resp)
+			Expect(err).To(BeNil())
+
+			Expect(resp.Data).To(HaveLen(20))
+			justice := resp.Data[0]
+			Expect(justice.Name).To(Equal("Justice"))
+			Expect(justice.ID).To(Equal(6404))
+		})
+	})
+
+	Describe("Top Tracks", func() {
+		It("parses the top tracks response correctly", func() {
+			var resp TopTracks
+			body, err := os.ReadFile("tests/fixtures/deezer.artist.top.json")
+			Expect(err).To(BeNil())
+			err = json.Unmarshal(body, &resp)
+			Expect(err).To(BeNil())
+
+			Expect(resp.Data).To(HaveLen(5))
+			track := resp.Data[0]
+			Expect(track.Title).To(Equal("Instant Crush (feat. Julian Casablancas)"))
+			Expect(track.ID).To(Equal(67238732))
+			Expect(track.Album.Title).To(Equal("Random Access Memories"))
+		})
+	})
+})

adapters/gotaglib/end_to_end_test.go

@@ -0,0 +1,274 @@
+package gotaglib
+
+import (
+	"io/fs"
+	"os"
+	"time"
+
+	"github.com/djherbis/times"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/metadata"
+	"github.com/navidrome/navidrome/utils/gg"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+type testFileInfo struct {
+	fs.FileInfo
+}
+
+func (t testFileInfo) BirthTime() time.Time {
+	if ts := times.Get(t.FileInfo); ts.HasBirthTime() {
+		return ts.BirthTime()
+	}
+	return t.FileInfo.ModTime()
+}
+
+var _ = Describe("Extractor", func() {
+	toP := func(name, sortName, mbid string) model.Participant {
+		return model.Participant{
+			Artist: model.Artist{Name: name, SortArtistName: sortName, MbzArtistID: mbid},
+		}
+	}
+
+	roles := []struct {
+		model.Role
+		model.ParticipantList
+	}{
+		{model.RoleComposer, model.ParticipantList{
+			toP("coma a", "a, coma", "bf13b584-f27c-43db-8f42-32898d33d4e2"),
+			toP("comb", "comb", "924039a2-09c6-4d29-9b4f-50cc54447d36"),
+		}},
+		{model.RoleLyricist, model.ParticipantList{
+			toP("la a", "a, la", "c84f648f-68a6-40a2-a0cb-d135b25da3c2"),
+			toP("lb", "lb", "0a7c582d-143a-4540-b4e9-77200835af65"),
+		}},
+		{model.RoleArranger, model.ParticipantList{
+			toP("aa", "", "4605a1d4-8d15-42a3-bd00-9c20e42f71e6"),
+			toP("ab", "", "002f0ff8-77bf-42cc-8216-61a9c43dc145"),
+		}},
+		{model.RoleConductor, model.ParticipantList{
+			toP("cona", "", "af86879b-2141-42af-bad2-389a4dc91489"),
+			toP("conb", "", "3dfa3c70-d7d3-4b97-b953-c298dd305e12"),
+		}},
+		{model.RoleDirector, model.ParticipantList{
+			toP("dia", "", "f943187f-73de-4794-be47-88c66f0fd0f4"),
+			toP("dib", "", "bceb75da-1853-4b3d-b399-b27f0cafc389"),
+		}},
+		{model.RoleEngineer, model.ParticipantList{
+			toP("ea", "", "f634bf6d-d66a-425d-888a-28ad39392759"),
+			toP("eb", "", "243d64ae-d514-44e1-901a-b918d692baee"),
+		}},
+		{model.RoleProducer, model.ParticipantList{
+			toP("pra", "", "d971c8d7-999c-4a5f-ac31-719721ab35d6"),
+			toP("prb", "", "f0a09070-9324-434f-a599-6d25ded87b69"),
+		}},
+		{model.RoleRemixer, model.ParticipantList{
+			toP("ra", "", "c7dc6095-9534-4c72-87cc-aea0103462cf"),
+			toP("rb", "", "8ebeef51-c08c-4736-992f-c37870becedd"),
+		}},
+		{model.RoleDJMixer, model.ParticipantList{
+			toP("dja", "", "d063f13b-7589-4efc-ab7f-c60e6db17247"),
+			toP("djb", "", "3636670c-385f-4212-89c8-0ff51d6bc456"),
+		}},
+		{model.RoleMixer, model.ParticipantList{
+			toP("ma", "", "53fb5a2d-7016-427e-a563-d91819a5f35a"),
+			toP("mb", "", "64c13e65-f0da-4ab9-a300-71ee53b0376a"),
+		}},
+	}
+
+	var e *extractor
+
+	parseTestFile := func(path string) *model.MediaFile {
+		mds, err := e.Parse(path)
+		Expect(err).ToNot(HaveOccurred())
+
+		info, ok := mds[path]
+		Expect(ok).To(BeTrue())
+
+		fileInfo, err := os.Stat(path)
+		Expect(err).ToNot(HaveOccurred())
+		info.FileInfo = testFileInfo{FileInfo: fileInfo}
+
+		metadata := metadata.New(path, info)
+		mf := metadata.ToMediaFile(1, "folderID")
+		return &mf
+	}
+
+	BeforeEach(func() {
+		e = &extractor{fs: os.DirFS(".")}
+	})
+
+	Describe("ReplayGain", func() {
+		DescribeTable("test replaygain end-to-end", func(file string, trackGain, trackPeak, albumGain, albumPeak *float64) {
+			mf := parseTestFile("tests/fixtures/" + file)
+
+			Expect(mf.RGTrackGain).To(Equal(trackGain))
+			Expect(mf.RGTrackPeak).To(Equal(trackPeak))
+			Expect(mf.RGAlbumGain).To(Equal(albumGain))
+			Expect(mf.RGAlbumPeak).To(Equal(albumPeak))
+		},
+			Entry("mp3 with no replaygain", "no_replaygain.mp3", nil, nil, nil, nil),
+			Entry("mp3 with no zero replaygain", "zero_replaygain.mp3", gg.P(0.0), gg.P(1.0), gg.P(0.0), gg.P(1.0)),
+		)
+	})
+
+	Describe("lyrics", func() {
+		makeLyrics := func(code, secondLine string) model.Lyrics {
+			return model.Lyrics{
+				DisplayArtist: "",
+				DisplayTitle:  "",
+				Lang:          code,
+				Line: []model.Line{
+					{Start: gg.P(int64(0)), Value: "This is"},
+					{Start: gg.P(int64(2500)), Value: secondLine},
+				},
+				Offset: nil,
+				Synced: true,
+			}
+		}
+
+		It("should fetch both synced and unsynced lyrics in mixed flac", func() {
+			mf := parseTestFile("tests/fixtures/mixed-lyrics.flac")
+
+			lyrics, err := mf.StructuredLyrics()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(lyrics).To(HaveLen(2))
+
+			Expect(lyrics[0].Synced).To(BeTrue())
+			Expect(lyrics[1].Synced).To(BeFalse())
+		})
+
+		It("should handle mp3 with uslt and sylt", func() {
+			mf := parseTestFile("tests/fixtures/test.mp3")
+
+			lyrics, err := mf.StructuredLyrics()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(lyrics).To(HaveLen(4))
+
+			engSylt := makeLyrics("eng", "English SYLT")
+			engUslt := makeLyrics("eng", "English")
+			unsSylt := makeLyrics("xxx", "unspecified SYLT")
+			unsUslt := makeLyrics("xxx", "unspecified")
+
+			Expect(lyrics).To(ConsistOf(engSylt, engUslt, unsSylt, unsUslt))
+		})
+
+		DescribeTable("format-specific lyrics", func(file string, isId3 bool) {
+			mf := parseTestFile("tests/fixtures/" + file)
+
+			lyrics, err := mf.StructuredLyrics()
+			Expect(err).To(Not(HaveOccurred()))
+			Expect(lyrics).To(HaveLen(2))
+
+			unspec := makeLyrics("xxx", "unspecified")
+			eng := makeLyrics("xxx", "English")
+
+			if isId3 {
+				eng.Lang = "eng"
+			}
+
+			Expect(lyrics).To(Or(
+				Equal(model.LyricList{unspec, eng}),
+				Equal(model.LyricList{eng, unspec})))
+		},
+			Entry("flac", "test.flac", false),
+			Entry("m4a", "test.m4a", false),
+			Entry("ogg", "test.ogg", false),
+			Entry("wma", "test.wma", false),
+			Entry("wv", "test.wv", false),
+			Entry("wav", "test.wav", true),
+			Entry("aiff", "test.aiff", true),
+		)
+	})
+
+	Describe("Participants", func() {
+		DescribeTable("test tags consistent across formats", func(format string) {
+			mf := parseTestFile("tests/fixtures/test." + format)
+
+			for _, data := range roles {
+				role := data.Role
+				artists := data.ParticipantList
+
+				actual := mf.Participants[role]
+				Expect(actual).To(HaveLen(len(artists)))
+
+				for i := range artists {
+					actualArtist := actual[i]
+					expectedArtist := artists[i]
+
+					Expect(actualArtist.Name).To(Equal(expectedArtist.Name))
+					Expect(actualArtist.SortArtistName).To(Equal(expectedArtist.SortArtistName))
+					Expect(actualArtist.MbzArtistID).To(Equal(expectedArtist.MbzArtistID))
+				}
+			}
+
+			if format != "m4a" {
+				performers := mf.Participants[model.RolePerformer]
+				Expect(performers).To(HaveLen(8))
+
+				rules := map[string][]string{
+					"pgaa": {"2fd0b311-9fa8-4ff9-be5d-f6f3d16b835e", "Guitar"},
+					"pgbb": {"223d030b-bf97-4c2a-ad26-b7f7bbe25c93", "Guitar", ""},
+					"pvaa": {"cb195f72-448f-41c8-b962-3f3c13d09d38", "Vocals"},
+					"pvbb": {"60a1f832-8ca2-49f6-8660-84d57f07b520", "Vocals", "Flute"},
+					"pfaa": {"51fb40c-0305-4bf9-a11b-2ee615277725", "", "Flute"},
+				}
+
+				for name, rule := range rules {
+					mbid := rule[0]
+					for i := 1; i < len(rule); i++ {
+						found := false
+
+						for _, mapped := range performers {
+							if mapped.Name == name && mapped.MbzArtistID == mbid && mapped.SubRole == rule[i] {
+								found = true
+								break
+							}
+						}
+
+						Expect(found).To(BeTrue(), "Could not find matching artist")
+					}
+				}
+			}
+		},
+			Entry("FLAC format", "flac"),
+			Entry("M4a format", "m4a"),
+			Entry("OGG format", "ogg"),
+			Entry("WV format", "wv"),
+
+			Entry("MP3 format", "mp3"),
+			Entry("WAV format", "wav"),
+			Entry("AIFF format", "aiff"),
+		)
+
+		It("should parse wma", func() {
+			mf := parseTestFile("tests/fixtures/test.wma")
+
+			for _, data := range roles {
+				role := data.Role
+				artists := data.ParticipantList
+				actual := mf.Participants[role]
+
+				// WMA has no Arranger role
+				if role == model.RoleArranger {
+					Expect(actual).To(HaveLen(0))
+					continue
+				}
+
+				Expect(actual).To(HaveLen(len(artists)), role.String())
+
+				// For some bizarre reason, the order is inverted. We also don't get
+				// sort names or MBIDs
+				for i := range artists {
+					idx := len(artists) - 1 - i
+
+					actualArtist := actual[i]
+					expectedArtist := artists[idx]
+
+					Expect(actualArtist.Name).To(Equal(expectedArtist.Name))
+				}
+			}
+		})
+	})
+})

adapters/gotaglib/gotaglib.go

@@ -0,0 +1,276 @@
+// Package gotaglib provides an alternative metadata extractor using go-taglib,
+// a pure Go (WASM-based) implementation of TagLib.
+//
+// This extractor aims for parity with the CGO-based taglib extractor. It uses
+// TagLib's PropertyMap interface for standard tags. The File handle API provides
+// efficient access to format-specific tags (ID3v2 frames, MP4 atoms, ASF attributes)
+// through a single file open operation.
+//
+// This extractor is registered under the name "taglib". It only works with a filesystem
+// (fs.FS) and does not support direct local file paths. Files returned by the filesystem
+// must implement io.ReadSeeker for go-taglib to read them.
+package gotaglib
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"runtime/debug"
+	"strings"
+	"time"
+
+	"github.com/navidrome/navidrome/core/storage/local"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model/metadata"
+	"go.senan.xyz/taglib"
+)
+
+type extractor struct {
+	fs fs.FS
+}
+
+func (e extractor) Parse(files ...string) (map[string]metadata.Info, error) {
+	results := make(map[string]metadata.Info)
+	for _, path := range files {
+		props, err := e.extractMetadata(path)
+		if err != nil {
+			continue
+		}
+		results[path] = *props
+	}
+	return results, nil
+}
+
+func (e extractor) Version() string {
+	return "go-taglib (TagLib 2.1.1 WASM)"
+}
+
+func (e extractor) extractMetadata(filePath string) (*metadata.Info, error) {
+	f, close, err := e.openFile(filePath)
+	if err != nil {
+		return nil, err
+	}
+	defer close()
+
+	// Get all tags and properties in one go
+	allTags := f.AllTags()
+	props := f.Properties()
+
+	// Map properties to AudioProperties
+	ap := metadata.AudioProperties{
+		Duration:   props.Length.Round(time.Millisecond * 10),
+		BitRate:    int(props.Bitrate),
+		Channels:   int(props.Channels),
+		SampleRate: int(props.SampleRate),
+		BitDepth:   int(props.BitsPerSample),
+	}
+
+	// Convert normalized tags to lowercase keys (go-taglib returns UPPERCASE keys)
+	normalizedTags := make(map[string][]string, len(allTags.Tags))
+	for key, values := range allTags.Tags {
+		lowerKey := strings.ToLower(key)
+		normalizedTags[lowerKey] = values
+	}
+
+	// Process format-specific raw tags
+	processRawTags(allTags, normalizedTags)
+
+	// Parse track/disc totals from "N/Total" format
+	parseTuple(normalizedTags, "track")
+	parseTuple(normalizedTags, "disc")
+
+	// Adjust some ID3 tags
+	parseLyrics(normalizedTags)
+	parseTIPL(normalizedTags)
+	delete(normalizedTags, "tmcl") // TMCL is already parsed by TagLib
+
+	// Determine if file has embedded picture
+	hasPicture := len(props.Images) > 0
+
+	return &metadata.Info{
+		Tags:            normalizedTags,
+		AudioProperties: ap,
+		HasPicture:      hasPicture,
+	}, nil
+}
+
+// openFile opens the file at filePath using the extractor's filesystem.
+// It returns a TagLib File handle and a cleanup function to close resources.
+func (e extractor) openFile(filePath string) (f *taglib.File, closeFunc func(), err error) {
+	// Recover from panics in the WASM runtime (e.g., wazero failing to mmap executable memory
+	// on hardened systems like NixOS with MemoryDenyWriteExecute=true)
+	debug.SetPanicOnFault(true)
+	defer func() {
+		if r := recover(); r != nil {
+			log.Error("WASM runtime panic: This may be caused by a hardened system that blocks executable memory mapping.", "file", filePath, "panic", r)
+			err = fmt.Errorf("WASM runtime panic (hardened system?): %v", r)
+		}
+	}()
+
+	// Open the file from the filesystem
+	file, err := e.fs.Open(filePath)
+	if err != nil {
+		return nil, nil, err
+	}
+	rs, isSeekable := file.(io.ReadSeeker)
+	if !isSeekable {
+		file.Close()
+		return nil, nil, errors.New("file is not seekable")
+	}
+	f, err = taglib.OpenStream(rs, taglib.WithReadStyle(taglib.ReadStyleFast))
+	if err != nil {
+		file.Close()
+		return nil, nil, err
+	}
+	closeFunc = func() {
+		f.Close()
+		file.Close()
+	}
+	return f, closeFunc, nil
+}
+
+// parseTuple parses track/disc numbers in "N/Total" format and separates them.
+// For example, tracknumber="2/10" becomes tracknumber="2" and tracktotal="10".
+func parseTuple(tags map[string][]string, prop string) {
+	tagName := prop + "number"
+	tagTotal := prop + "total"
+	if value, ok := tags[tagName]; ok && len(value) > 0 {
+		parts := strings.Split(value[0], "/")
+		tags[tagName] = []string{parts[0]}
+		if len(parts) == 2 {
+			tags[tagTotal] = []string{parts[1]}
+		}
+	}
+}
+
+// parseLyrics ensures lyrics tags have a language code.
+// If lyrics exist without a language code, they are moved to "lyrics:xxx".
+func parseLyrics(tags map[string][]string) {
+	lyrics := tags["lyrics"]
+	if len(lyrics) > 0 {
+		tags["lyrics:xxx"] = lyrics
+		delete(tags, "lyrics")
+	}
+}
+
+// processRawTags processes format-specific raw tags based on the detected file format.
+// This handles ID3v2 frames (MP3/WAV/AIFF), MP4 atoms, and ASF attributes.
+func processRawTags(allTags taglib.AllTags, normalizedTags map[string][]string) {
+	switch allTags.Format {
+	case taglib.FormatMPEG, taglib.FormatWAV, taglib.FormatAIFF:
+		parseID3v2Frames(allTags.Raw, normalizedTags)
+	case taglib.FormatMP4:
+		parseMP4Atoms(allTags.Raw, normalizedTags)
+	case taglib.FormatASF:
+		parseASFAttributes(allTags.Raw, normalizedTags)
+	}
+}
+
+// parseID3v2Frames processes ID3v2 raw frames to extract USLT/SYLT with language codes.
+// This extracts language-specific lyrics that the standard Tags() doesn't provide.
+func parseID3v2Frames(rawFrames map[string][]string, tags map[string][]string) {
+	// Process frames that have language-specific data
+	for key, values := range rawFrames {
+		lowerKey := strings.ToLower(key)
+
+		// Handle USLT:xxx and SYLT:xxx (lyrics with language codes)
+		if strings.HasPrefix(lowerKey, "uslt:") || strings.HasPrefix(lowerKey, "sylt:") {
+			parts := strings.SplitN(lowerKey, ":", 2)
+			if len(parts) == 2 && parts[1] != "" {
+				lang := parts[1]
+				lyricsKey := "lyrics:" + lang
+				tags[lyricsKey] = append(tags[lyricsKey], values...)
+			}
+		}
+	}
+
+	// If we found any language-specific lyrics from ID3v2 frames, remove the generic lyrics
+	for key := range tags {
+		if strings.HasPrefix(key, "lyrics:") && key != "lyrics" {
+			delete(tags, "lyrics")
+			break
+		}
+	}
+}
+
+const iTunesKeyPrefix = "----:com.apple.iTunes:"
+
+// parseMP4Atoms processes MP4 raw atoms to get iTunes-specific tags.
+func parseMP4Atoms(rawAtoms map[string][]string, tags map[string][]string) {
+	// Process all atoms and add them to tags
+	for key, values := range rawAtoms {
+		// Strip iTunes prefix and convert to lowercase
+		normalizedKey := strings.TrimPrefix(key, iTunesKeyPrefix)
+		normalizedKey = strings.ToLower(normalizedKey)
+
+		// Only add if the tag doesn't already exist (avoid duplication with PropertyMap)
+		if _, exists := tags[normalizedKey]; !exists {
+			tags[normalizedKey] = values
+		}
+	}
+}
+
+// parseASFAttributes processes ASF raw attributes to get WMA-specific tags.
+func parseASFAttributes(rawAttrs map[string][]string, tags map[string][]string) {
+	// Process all attributes and add them to tags
+	for key, values := range rawAttrs {
+		normalizedKey := strings.ToLower(key)
+
+		// Only add if the tag doesn't already exist (avoid duplication with PropertyMap)
+		if _, exists := tags[normalizedKey]; !exists {
+			tags[normalizedKey] = values
+		}
+	}
+}
+
+// These are the only roles we support, based on Picard's tag map:
+// https://picard-docs.musicbrainz.org/downloads/MusicBrainz_Picard_Tag_Map.html
+var tiplMapping = map[string]string{
+	"arranger": "arranger",
+	"engineer": "engineer",
+	"producer": "producer",
+	"mix":      "mixer",
+	"DJ-mix":   "djmixer",
+}
+
+// parseTIPL parses the ID3v2.4 TIPL frame string, which is received from TagLib in the format:
+//
+//	"arranger Andrew Powell engineer Chris Blair engineer Pat Stapley producer Eric Woolfson".
+//
+// and breaks it down into a map of roles and names, e.g.:
+//
+//	{"arranger": ["Andrew Powell"], "engineer": ["Chris Blair", "Pat Stapley"], "producer": ["Eric Woolfson"]}.
+func parseTIPL(tags map[string][]string) {
+	tipl := tags["tipl"]
+	if len(tipl) == 0 {
+		return
+	}
+	addRole := func(currentRole string, currentValue []string) {
+		if currentRole != "" && len(currentValue) > 0 {
+			role := tiplMapping[currentRole]
+			tags[role] = append(tags[role], strings.Join(currentValue, " "))
+		}
+	}
+	var currentRole string
+	var currentValue []string
+	for _, part := range strings.Split(tipl[0], " ") {
+		if _, ok := tiplMapping[part]; ok {
+			addRole(currentRole, currentValue)
+			currentRole = part
+			currentValue = nil
+			continue
+		}
+		currentValue = append(currentValue, part)
+	}
+	addRole(currentRole, currentValue)
+	delete(tags, "tipl")
+}
+
+var _ local.Extractor = (*extractor)(nil)
+
+func init() {
+	local.RegisterExtractor("taglib", func(fsys fs.FS, baseDir string) local.Extractor {
+		return &extractor{fsys}
+	})
+}

adapters/gotaglib/gotaglib_suite_test.go

@@ -0,0 +1,17 @@
+package gotaglib
+
+import (
+	"testing"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestGoTagLib(t *testing.T) {
+	tests.Init(t, true)
+	log.SetLevel(log.LevelFatal)
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "GoTagLib Suite")
+}

adapters/gotaglib/gotaglib_test.go

@@ -0,0 +1,302 @@
+package gotaglib
+
+import (
+	"io/fs"
+	"os"
+	"strings"
+
+	"github.com/navidrome/navidrome/utils"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Extractor", func() {
+	var e *extractor
+
+	BeforeEach(func() {
+		e = &extractor{fs: os.DirFS(".")}
+	})
+
+	Describe("Parse", func() {
+		It("correctly parses metadata from all files in folder", func() {
+			mds, err := e.Parse(
+				"tests/fixtures/test.mp3",
+				"tests/fixtures/test.ogg",
+			)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(mds).To(HaveLen(2))
+
+			// Test MP3
+			m := mds["tests/fixtures/test.mp3"]
+			Expect(m.Tags).To(HaveKeyWithValue("title", []string{"Song"}))
+			Expect(m.Tags).To(HaveKeyWithValue("album", []string{"Album"}))
+			Expect(m.Tags).To(HaveKeyWithValue("artist", []string{"Artist"}))
+			Expect(m.Tags).To(HaveKeyWithValue("albumartist", []string{"Album Artist"}))
+
+			Expect(m.HasPicture).To(BeTrue())
+			Expect(m.AudioProperties.Duration.String()).To(Equal("1.02s"))
+			Expect(m.AudioProperties.BitRate).To(Equal(192))
+			Expect(m.AudioProperties.Channels).To(Equal(2))
+			Expect(m.AudioProperties.SampleRate).To(Equal(44100))
+
+			Expect(m.Tags).To(Or(
+				HaveKeyWithValue("compilation", []string{"1"}),
+				HaveKeyWithValue("tcmp", []string{"1"})),
+			)
+			Expect(m.Tags).To(HaveKeyWithValue("genre", []string{"Rock"}))
+			Expect(m.Tags).To(HaveKeyWithValue("date", []string{"2014-05-21"}))
+			Expect(m.Tags).To(HaveKeyWithValue("originaldate", []string{"1996-11-21"}))
+			Expect(m.Tags).To(HaveKeyWithValue("releasedate", []string{"2020-12-31"}))
+			Expect(m.Tags).To(HaveKeyWithValue("discnumber", []string{"1"}))
+			Expect(m.Tags).To(HaveKeyWithValue("disctotal", []string{"2"}))
+			Expect(m.Tags).To(HaveKeyWithValue("comment", []string{"Comment1\nComment2"}))
+			Expect(m.Tags).To(HaveKeyWithValue("bpm", []string{"123"}))
+			Expect(m.Tags).To(HaveKeyWithValue("replaygain_album_gain", []string{"+3.21518 dB"}))
+			Expect(m.Tags).To(HaveKeyWithValue("replaygain_album_peak", []string{"0.9125"}))
+			Expect(m.Tags).To(HaveKeyWithValue("replaygain_track_gain", []string{"-1.48 dB"}))
+			Expect(m.Tags).To(HaveKeyWithValue("replaygain_track_peak", []string{"0.4512"}))
+
+			Expect(m.Tags).To(HaveKeyWithValue("tracknumber", []string{"2"}))
+			Expect(m.Tags).To(HaveKeyWithValue("tracktotal", []string{"10"}))
+
+			Expect(m.Tags).ToNot(HaveKey("lyrics"))
+			Expect(m.Tags).To(Or(HaveKeyWithValue("lyrics:eng", []string{
+				"[00:00.00]This is\n[00:02.50]English SYLT\n",
+				"[00:00.00]This is\n[00:02.50]English",
+			}), HaveKeyWithValue("lyrics:eng", []string{
+				"[00:00.00]This is\n[00:02.50]English",
+				"[00:00.00]This is\n[00:02.50]English SYLT\n",
+			})))
+			Expect(m.Tags).To(Or(HaveKeyWithValue("lyrics:xxx", []string{
+				"[00:00.00]This is\n[00:02.50]unspecified SYLT\n",
+				"[00:00.00]This is\n[00:02.50]unspecified",
+			}), HaveKeyWithValue("lyrics:xxx", []string{
+				"[00:00.00]This is\n[00:02.50]unspecified",
+				"[00:00.00]This is\n[00:02.50]unspecified SYLT\n",
+			})))
+
+			// Test OGG
+			m = mds["tests/fixtures/test.ogg"]
+			Expect(err).To(BeNil())
+			Expect(m.Tags).To(HaveKeyWithValue("fbpm", []string{"141.7"}))
+
+			// TagLib 1.12 returns 18, previous versions return 39.
+			// See https://github.com/taglib/taglib/commit/2f238921824741b2cfe6fbfbfc9701d9827ab06b
+			Expect(m.AudioProperties.BitRate).To(BeElementOf(18, 19, 39, 40, 43, 49))
+			Expect(m.AudioProperties.Channels).To(BeElementOf(2))
+			Expect(m.AudioProperties.SampleRate).To(BeElementOf(8000))
+			Expect(m.HasPicture).To(BeTrue())
+		})
+
+		DescribeTable("Format-Specific tests",
+			func(file, duration string, channels, samplerate, bitdepth int, albumGain, albumPeak, trackGain, trackPeak string, id3Lyrics bool, image bool) {
+				file = "tests/fixtures/" + file
+				mds, err := e.Parse(file)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(mds).To(HaveLen(1))
+
+				m := mds[file]
+
+				Expect(m.HasPicture).To(Equal(image))
+				Expect(m.AudioProperties.Duration.String()).To(Equal(duration))
+				Expect(m.AudioProperties.Channels).To(Equal(channels))
+				Expect(m.AudioProperties.SampleRate).To(Equal(samplerate))
+				Expect(m.AudioProperties.BitDepth).To(Equal(bitdepth))
+
+				Expect(m.Tags).To(Or(
+					HaveKeyWithValue("replaygain_album_gain", []string{albumGain}),
+					HaveKeyWithValue("----:com.apple.itunes:replaygain_album_gain", []string{albumGain}),
+				))
+
+				Expect(m.Tags).To(Or(
+					HaveKeyWithValue("replaygain_album_peak", []string{albumPeak}),
+					HaveKeyWithValue("----:com.apple.itunes:replaygain_album_peak", []string{albumPeak}),
+				))
+				Expect(m.Tags).To(Or(
+					HaveKeyWithValue("replaygain_track_gain", []string{trackGain}),
+					HaveKeyWithValue("----:com.apple.itunes:replaygain_track_gain", []string{trackGain}),
+				))
+				Expect(m.Tags).To(Or(
+					HaveKeyWithValue("replaygain_track_peak", []string{trackPeak}),
+					HaveKeyWithValue("----:com.apple.itunes:replaygain_track_peak", []string{trackPeak}),
+				))
+
+				Expect(m.Tags).To(HaveKeyWithValue("title", []string{"Title"}))
+				Expect(m.Tags).To(HaveKeyWithValue("album", []string{"Album"}))
+				Expect(m.Tags).To(HaveKeyWithValue("artist", []string{"Artist"}))
+				Expect(m.Tags).To(HaveKeyWithValue("albumartist", []string{"Album Artist"}))
+				Expect(m.Tags).To(HaveKeyWithValue("genre", []string{"Rock"}))
+				Expect(m.Tags).To(HaveKeyWithValue("date", []string{"2014"}))
+
+				Expect(m.Tags).To(HaveKeyWithValue("bpm", []string{"123"}))
+				Expect(m.Tags).To(Or(
+					HaveKeyWithValue("tracknumber", []string{"3"}),
+					HaveKeyWithValue("tracknumber", []string{"3/10"}),
+				))
+				if !strings.HasSuffix(file, "test.wma") {
+					// TODO Not sure why this is not working for WMA
+					Expect(m.Tags).To(HaveKeyWithValue("tracktotal", []string{"10"}))
+				}
+				Expect(m.Tags).To(Or(
+					HaveKeyWithValue("discnumber", []string{"1"}),
+					HaveKeyWithValue("discnumber", []string{"1/2"}),
+				))
+				Expect(m.Tags).To(HaveKeyWithValue("disctotal", []string{"2"}))
+
+				// WMA does not have a "compilation" tag, but "wm/iscompilation"
+				Expect(m.Tags).To(Or(
+					HaveKeyWithValue("compilation", []string{"1"}),
+					HaveKeyWithValue("wm/iscompilation", []string{"1"})),
+				)
+
+				if id3Lyrics {
+					Expect(m.Tags).To(HaveKeyWithValue("lyrics:eng", []string{
+						"[00:00.00]This is\n[00:02.50]English",
+					}))
+					Expect(m.Tags).To(HaveKeyWithValue("lyrics:xxx", []string{
+						"[00:00.00]This is\n[00:02.50]unspecified",
+					}))
+				} else {
+					Expect(m.Tags).To(HaveKeyWithValue("lyrics:xxx", []string{
+						"[00:00.00]This is\n[00:02.50]unspecified",
+						"[00:00.00]This is\n[00:02.50]English",
+					}))
+				}
+
+				Expect(m.Tags).To(HaveKeyWithValue("comment", []string{"Comment1\nComment2"}))
+			},
+
+			// ffmpeg -f lavfi -i "sine=frequency=1200:duration=1" test.flac
+			Entry("correctly parses flac tags", "test.flac", "1s", 1, 44100, 16, "+4.06 dB", "0.12496948", "+4.06 dB", "0.12496948", false, true),
+
+			Entry("correctly parses m4a (aac) gain tags", "01 Invisible (RED) Edit Version.m4a", "1.04s", 2, 44100, 16, "0.37", "0.48", "0.37", "0.48", false, true),
+			Entry("correctly parses m4a (aac) gain tags (uppercase)", "test.m4a", "1.04s", 2, 44100, 16, "0.37", "0.48", "0.37", "0.48", false, true),
+			Entry("correctly parses ogg (vorbis) tags", "test.ogg", "1.04s", 2, 8000, 0, "+7.64 dB", "0.11772506", "+7.64 dB", "0.11772506", false, true),
+
+			// ffmpeg -f lavfi -i "sine=frequency=900:duration=1" test.wma
+			// Weird note: for the tag parsing to work, the lyrics are actually stored in the reverse order
+			Entry("correctly parses wma/asf tags", "test.wma", "1.02s", 1, 44100, 16, "3.27 dB", "0.132914", "3.27 dB", "0.132914", false, true),
+
+			// ffmpeg -f lavfi -i "sine=frequency=800:duration=1" test.wv
+			Entry("correctly parses wv (wavpak) tags", "test.wv", "1s", 1, 44100, 16, "3.43 dB", "0.125061", "3.43 dB", "0.125061", false, true),
+
+			// ffmpeg -f lavfi -i "sine=frequency=1000:duration=1" test.wav
+			Entry("correctly parses wav tags", "test.wav", "1s", 1, 44100, 16, "3.06 dB", "0.125056", "3.06 dB", "0.125056", true, true),
+
+			// ffmpeg -f lavfi -i "sine=frequency=1400:duration=1" test.aiff
+			Entry("correctly parses aiff tags", "test.aiff", "1s", 1, 44100, 16, "2.00 dB", "0.124972", "2.00 dB", "0.124972", true, true),
+		)
+
+		// Skip these tests when running as root
+		Context("Access Forbidden", func() {
+			var accessForbiddenFile string
+			var RegularUserContext = XContext
+			var isRegularUser = os.Getuid() != 0
+			if isRegularUser {
+				RegularUserContext = Context
+			}
+
+			// Only run permission tests if we are not root
+			RegularUserContext("when run without root privileges", func() {
+				BeforeEach(func() {
+					// Use root fs for absolute paths in temp directory
+					e = &extractor{fs: os.DirFS("/")}
+					accessForbiddenFile = utils.TempFileName("access_forbidden-", ".mp3")
+
+					f, err := os.OpenFile(accessForbiddenFile, os.O_WRONLY|os.O_CREATE, 0222)
+					Expect(err).ToNot(HaveOccurred())
+
+					DeferCleanup(func() {
+						Expect(f.Close()).To(Succeed())
+						Expect(os.Remove(accessForbiddenFile)).To(Succeed())
+					})
+				})
+
+				It("correctly handle unreadable file due to insufficient read permission", func() {
+					// Strip leading slash for DirFS rooted at "/"
+					_, err := e.extractMetadata(accessForbiddenFile[1:])
+					Expect(err).To(MatchError(os.ErrPermission))
+				})
+
+				It("skips the file if it cannot be read", func() {
+					// Get current working directory to construct paths relative to root
+					cwd, err := os.Getwd()
+					Expect(err).ToNot(HaveOccurred())
+					// Strip leading slash for DirFS rooted at "/"
+					files := []string{
+						cwd[1:] + "/tests/fixtures/test.mp3",
+						cwd[1:] + "/tests/fixtures/test.ogg",
+						accessForbiddenFile[1:],
+					}
+					mds, err := e.Parse(files...)
+					Expect(err).NotTo(HaveOccurred())
+					Expect(mds).To(HaveLen(2))
+					Expect(mds).ToNot(HaveKey(accessForbiddenFile[1:]))
+				})
+			})
+		})
+
+	})
+
+	Describe("Error Checking", func() {
+		It("returns a generic ErrPath if file does not exist", func() {
+			testFilePath := "tests/fixtures/NON_EXISTENT.ogg"
+			_, err := e.extractMetadata(testFilePath)
+			Expect(err).To(MatchError(fs.ErrNotExist))
+		})
+		It("does not throw a SIGSEGV error when reading a file with an invalid frame", func() {
+			// File has an empty TDAT frame
+			md, err := e.extractMetadata("tests/fixtures/invalid-files/test-invalid-frame.mp3")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(md.Tags).To(HaveKeyWithValue("albumartist", []string{"Elvis Presley"}))
+		})
+	})
+
+	Describe("parseTIPL", func() {
+		var tags map[string][]string
+
+		BeforeEach(func() {
+			tags = make(map[string][]string)
+		})
+
+		Context("when the TIPL string is populated", func() {
+			It("correctly parses roles and names", func() {
+				tags["tipl"] = []string{"arranger Andrew Powell DJ-mix François Kevorkian DJ-mix Jane Doe engineer Chris Blair"}
+				parseTIPL(tags)
+				Expect(tags["arranger"]).To(ConsistOf("Andrew Powell"))
+				Expect(tags["engineer"]).To(ConsistOf("Chris Blair"))
+				Expect(tags["djmixer"]).To(ConsistOf("François Kevorkian", "Jane Doe"))
+			})
+
+			It("handles multiple names for a single role", func() {
+				tags["tipl"] = []string{"engineer Pat Stapley producer Eric Woolfson engineer Chris Blair"}
+				parseTIPL(tags)
+				Expect(tags["producer"]).To(ConsistOf("Eric Woolfson"))
+				Expect(tags["engineer"]).To(ConsistOf("Pat Stapley", "Chris Blair"))
+			})
+
+			It("discards roles without names", func() {
+				tags["tipl"] = []string{"engineer Pat Stapley producer engineer Chris Blair"}
+				parseTIPL(tags)
+				Expect(tags).ToNot(HaveKey("producer"))
+				Expect(tags["engineer"]).To(ConsistOf("Pat Stapley", "Chris Blair"))
+			})
+		})
+
+		Context("when the TIPL string is empty", func() {
+			It("does nothing", func() {
+				tags["tipl"] = []string{""}
+				parseTIPL(tags)
+				Expect(tags).To(BeEmpty())
+			})
+		})
+
+		Context("when the TIPL is not present", func() {
+			It("does nothing", func() {
+				parseTIPL(tags)
+				Expect(tags).To(BeEmpty())
+			})
+		})
+	})
+
+})

adapters/lastfm/agent.go

@@ -26,8 +26,8 @@ const (
 	sessionKeyProperty = "LastFMSessionKey"
 )
 
-var ignoredBiographies = []string{
-	// Unknown Artist
+var ignoredContent = []string{
+	// Empty Artist/Album
 	`<a href="https://www.last.fm/music/`,
 }
 
@@ -36,8 +36,9 @@ type lastfmAgent struct {
 	sessionKeys  *agents.SessionKeys
 	apiKey       string
 	secret       string
-	lang         string
+	languages    []string
 	client       *client
+	httpClient   httpDoer
 	getInfoMutex sync.Mutex
 }
 
@@ -47,7 +48,7 @@ func lastFMConstructor(ds model.DataStore) *lastfmAgent {
 	}
 	l := &lastfmAgent{
 		ds:          ds,
-		lang:        conf.Server.LastFM.Language,
+		languages:   conf.Server.LastFM.Languages,
 		apiKey:      conf.Server.LastFM.ApiKey,
 		secret:      conf.Server.LastFM.Secret,
 		sessionKeys: &agents.SessionKeys{DataStore: ds, KeyName: sessionKeyProperty},
@@ -56,7 +57,8 @@ func lastFMConstructor(ds model.DataStore) *lastfmAgent {
 		Timeout: consts.DefaultHttpClientTimeOut,
 	}
 	chc := cache.NewHTTPClient(hc, consts.DefaultHttpClientTimeOut)
-	l.client = newClient(l.apiKey, l.secret, l.lang, chc)
+	l.httpClient = chc
+	l.client = newClient(l.apiKey, l.secret, chc)
 	return l
 }
 
@@ -66,22 +68,54 @@ func (l *lastfmAgent) AgentName() string {
 
 var imageRegex = regexp.MustCompile(`u\/(\d+)`)
 
+// isValidContent checks if content is non-empty and not in the ignored list
+func isValidContent(content string) bool {
+	content = strings.TrimSpace(content)
+	if content == "" {
+		return false
+	}
+	for _, ign := range ignoredContent {
+		if strings.HasPrefix(content, ign) {
+			return false
+		}
+	}
+	return true
+}
+
 func (l *lastfmAgent) GetAlbumInfo(ctx context.Context, name, artist, mbid string) (*agents.AlbumInfo, error) {
-	a, err := l.callAlbumGetInfo(ctx, name, artist, mbid)
+	var a *Album
+	var resp agents.AlbumInfo
+	for _, lang := range l.languages {
+		var err error
+		a, err = l.callAlbumGetInfo(ctx, name, artist, mbid, lang)
+		if err != nil {
+			return nil, err
+		}
+		resp.Name = a.Name
+		resp.MBID = a.MBID
+		resp.URL = a.URL
+		if isValidContent(a.Description.Summary) {
+			resp.Description = strings.TrimSpace(a.Description.Summary)
+			return &resp, nil
+		}
+		log.Debug(ctx, "LastFM/album.getInfo returned empty/ignored description, trying next language", "album", name, "artist", artist, "lang", lang)
+	}
+	// This condition should not be hit (languages default to ["en"]), but just in case
+	if a == nil {
+		return nil, agents.ErrNotFound
+	}
+	return &resp, nil
+}
+
+func (l *lastfmAgent) GetAlbumImages(ctx context.Context, name, artist, mbid string) ([]agents.ExternalImage, error) {
+	a, err := l.callAlbumGetInfo(ctx, name, artist, mbid, l.languages[0])
 	if err != nil {
 		return nil, err
 	}
 
-	response := agents.AlbumInfo{
-		Name:        a.Name,
-		MBID:        a.MBID,
-		Description: a.Description.Summary,
-		URL:         a.URL,
-		Images:      make([]agents.ExternalImage, 0),
-	}
-
 	// Last.fm can return duplicate sizes.
 	seenSizes := map[int]bool{}
+	images := make([]agents.ExternalImage, 0)
 
 	// This assumes that Last.fm returns images with size small, medium, and large.
 	// This is true as of December 29, 2022
@@ -92,27 +126,24 @@ func (l *lastfmAgent) GetAlbumInfo(ctx context.Context, name, artist, mbid strin
 			log.Trace(ctx, "LastFM/albuminfo image URL does not match expected regex or is empty", "url", img.URL, "size", img.Size)
 			continue
 		}
-
 		numericSize, err := strconv.Atoi(size[0][2:])
 		if err != nil {
 			log.Error(ctx, "LastFM/albuminfo image URL does not match expected regex", "url", img.URL, "size", img.Size, err)
 			return nil, err
-		} else {
-			if _, exists := seenSizes[numericSize]; !exists {
-				response.Images = append(response.Images, agents.ExternalImage{
-					Size: numericSize,
-					URL:  img.URL,
-				})
-				seenSizes[numericSize] = true
-			}
+		}
+		if _, exists := seenSizes[numericSize]; !exists {
+			images = append(images, agents.ExternalImage{
+				Size: numericSize,
+				URL:  img.URL,
+			})
+			seenSizes[numericSize] = true
 		}
 	}
-
-	return &response, nil
+	return images, nil
 }
 
 func (l *lastfmAgent) GetArtistMBID(ctx context.Context, id string, name string) (string, error) {
-	a, err := l.callArtistGetInfo(ctx, name)
+	a, err := l.callArtistGetInfo(ctx, name, l.languages[0])
 	if err != nil {
 		return "", err
 	}
@@ -123,7 +154,7 @@ func (l *lastfmAgent) GetArtistMBID(ctx context.Context, id string, name string)
 }
 
 func (l *lastfmAgent) GetArtistURL(ctx context.Context, id, name, mbid string) (string, error) {
-	a, err := l.callArtistGetInfo(ctx, name)
+	a, err := l.callArtistGetInfo(ctx, name, l.languages[0])
 	if err != nil {
 		return "", err
 	}
@@ -134,20 +165,17 @@ func (l *lastfmAgent) GetArtistURL(ctx context.Context, id, name, mbid string) (
 }
 
 func (l *lastfmAgent) GetArtistBiography(ctx context.Context, id, name, mbid string) (string, error) {
-	a, err := l.callArtistGetInfo(ctx, name)
-	if err != nil {
-		return "", err
-	}
-	a.Bio.Summary = strings.TrimSpace(a.Bio.Summary)
-	if a.Bio.Summary == "" {
-		return "", agents.ErrNotFound
-	}
-	for _, ign := range ignoredBiographies {
-		if strings.HasPrefix(a.Bio.Summary, ign) {
-			return "", nil
+	for _, lang := range l.languages {
+		a, err := l.callArtistGetInfo(ctx, name, lang)
+		if err != nil {
+			return "", err
 		}
+		if isValidContent(a.Bio.Summary) {
+			return strings.TrimSpace(a.Bio.Summary), nil
+		}
+		log.Debug(ctx, "LastFM/artist.getInfo returned empty/ignored biography, trying next language", "artist", name, "lang", lang)
 	}
-	return a.Bio.Summary, nil
+	return "", agents.ErrNotFound
 }
 
 func (l *lastfmAgent) GetSimilarArtists(ctx context.Context, id, name, mbid string, limit int) ([]agents.Artist, error) {
@@ -186,14 +214,34 @@ func (l *lastfmAgent) GetArtistTopSongs(ctx context.Context, id, artistName, mbi
 	return res, nil
 }
 
-var artistOpenGraphQuery = cascadia.MustCompile(`html > head > meta[property="og:image"]`)
+func (l *lastfmAgent) GetSimilarSongsByTrack(ctx context.Context, id, name, artist, mbid string, count int) ([]agents.Song, error) {
+	resp, err := l.callTrackGetSimilar(ctx, name, artist, count)
+	if err != nil {
+		return nil, err
+	}
+	if len(resp) == 0 {
+		return nil, agents.ErrNotFound
+	}
+	res := make([]agents.Song, 0, len(resp))
+	for _, t := range resp {
+		res = append(res, agents.Song{
+			Name:       t.Name,
+			MBID:       t.MBID,
+			Artist:     t.Artist.Name,
+			ArtistMBID: t.Artist.MBID,
+		})
+	}
+	return res, nil
+}
+
+var (
+	artistOpenGraphQuery = cascadia.MustCompile(`html > head > meta[property="og:image"]`)
+	artistIgnoredImage   = "2a96cbd8b46e442fc41c2b86b821562f" // Last.fm artist placeholder image name
+)
 
 func (l *lastfmAgent) GetArtistImages(ctx context.Context, _, name, mbid string) ([]agents.ExternalImage, error) {
 	log.Debug(ctx, "Getting artist images from Last.fm", "name", name)
-	hc := http.Client{
-		Timeout: consts.DefaultHttpClientTimeOut,
-	}
-	a, err := l.callArtistGetInfo(ctx, name)
+	a, err := l.callArtistGetInfo(ctx, name, l.languages[0])
 	if err != nil {
 		return nil, fmt.Errorf("get artist info: %w", err)
 	}
@@ -201,7 +249,7 @@ func (l *lastfmAgent) GetArtistImages(ctx context.Context, _, name, mbid string)
 	if err != nil {
 		return nil, fmt.Errorf("create artist image request: %w", err)
 	}
-	resp, err := hc.Do(req)
+	resp, err := l.httpClient.Do(req)
 	if err != nil {
 		return nil, fmt.Errorf("get artist url: %w", err)
 	}
@@ -218,24 +266,29 @@ func (l *lastfmAgent) GetArtistImages(ctx context.Context, _, name, mbid string)
 		return res, nil
 	}
 	for _, attr := range n.Attr {
-		if attr.Key == "content" {
-			res = []agents.ExternalImage{
-				{URL: attr.Val},
-			}
-			break
+		if attr.Key != "content" {
+			continue
+		}
+		if strings.Contains(attr.Val, artistIgnoredImage) {
+			log.Debug(ctx, "Artist image is ignored default image", "name", name, "url", attr.Val)
+			return res, nil
+		}
+
+		res = []agents.ExternalImage{
+			{URL: attr.Val},
 		}
 	}
 	return res, nil
 }
 
-func (l *lastfmAgent) callAlbumGetInfo(ctx context.Context, name, artist, mbid string) (*Album, error) {
-	a, err := l.client.albumGetInfo(ctx, name, artist, mbid)
+func (l *lastfmAgent) callAlbumGetInfo(ctx context.Context, name, artist, mbid string, lang string) (*Album, error) {
+	a, err := l.client.albumGetInfo(ctx, name, artist, mbid, lang)
 	var lfErr *lastFMError
 	isLastFMError := errors.As(err, &lfErr)
 
 	if mbid != "" && (isLastFMError && lfErr.Code == 6) {
 		log.Debug(ctx, "LastFM/album.getInfo could not find album by mbid, trying again", "album", name, "mbid", mbid)
-		return l.callAlbumGetInfo(ctx, name, artist, "")
+		return l.callAlbumGetInfo(ctx, name, artist, "", lang)
 	}
 
 	if err != nil {
@@ -249,11 +302,11 @@ func (l *lastfmAgent) callAlbumGetInfo(ctx context.Context, name, artist, mbid s
 	return a, nil
 }
 
-func (l *lastfmAgent) callArtistGetInfo(ctx context.Context, name string) (*Artist, error) {
+func (l *lastfmAgent) callArtistGetInfo(ctx context.Context, name string, lang string) (*Artist, error) {
 	l.getInfoMutex.Lock()
 	defer l.getInfoMutex.Unlock()
 
-	a, err := l.client.artistGetInfo(ctx, name)
+	a, err := l.client.artistGetInfo(ctx, name, lang)
 	if err != nil {
 		log.Error(ctx, "Error calling LastFM/artist.getInfo", "artist", name, err)
 		return nil, err
@@ -279,27 +332,36 @@ func (l *lastfmAgent) callArtistGetTopTracks(ctx context.Context, artistName str
 	return t.Track, nil
 }
 
-func (l *lastfmAgent) getArtistForScrobble(track *model.MediaFile) string {
-	if conf.Server.LastFM.ScrobbleFirstArtistOnly && len(track.Participants[model.RoleArtist]) > 0 {
-		return track.Participants[model.RoleArtist][0].Name
+func (l *lastfmAgent) callTrackGetSimilar(ctx context.Context, name, artist string, count int) ([]SimilarTrack, error) {
+	s, err := l.client.trackGetSimilar(ctx, name, artist, count)
+	if err != nil {
+		log.Error(ctx, "Error calling LastFM/track.getSimilar", "track", name, "artist", artist, err)
+		return nil, err
 	}
-	return track.Artist
+	return s.Track, nil
 }
 
-func (l *lastfmAgent) NowPlaying(ctx context.Context, userId string, track *model.MediaFile) error {
+func (l *lastfmAgent) getArtistForScrobble(track *model.MediaFile, role model.Role, displayName string) string {
+	if conf.Server.LastFM.ScrobbleFirstArtistOnly && len(track.Participants[role]) > 0 {
+		return track.Participants[role][0].Name
+	}
+	return displayName
+}
+
+func (l *lastfmAgent) NowPlaying(ctx context.Context, userId string, track *model.MediaFile, position int) error {
 	sk, err := l.sessionKeys.Get(ctx, userId)
 	if err != nil || sk == "" {
 		return scrobbler.ErrNotAuthorized
 	}
 
 	err = l.client.updateNowPlaying(ctx, sk, ScrobbleInfo{
-		artist:      l.getArtistForScrobble(track),
+		artist:      l.getArtistForScrobble(track, model.RoleArtist, track.Artist),
 		track:       track.Title,
 		album:       track.Album,
 		trackNumber: track.TrackNumber,
 		mbid:        track.MbzRecordingID,
 		duration:    int(track.Duration),
-		albumArtist: track.AlbumArtist,
+		albumArtist: l.getArtistForScrobble(track, model.RoleAlbumArtist, track.AlbumArtist),
 	})
 	if err != nil {
 		log.Warn(ctx, "Last.fm client.updateNowPlaying returned error", "track", track.Title, err)
@@ -319,13 +381,13 @@ func (l *lastfmAgent) Scrobble(ctx context.Context, userId string, s scrobbler.S
 		return nil
 	}
 	err = l.client.scrobble(ctx, sk, ScrobbleInfo{
-		artist:      l.getArtistForScrobble(&s.MediaFile),
+		artist:      l.getArtistForScrobble(&s.MediaFile, model.RoleArtist, s.Artist),
 		track:       s.Title,
 		album:       s.Album,
 		trackNumber: s.TrackNumber,
 		mbid:        s.MbzRecordingID,
 		duration:    int(s.Duration),
-		albumArtist: s.AlbumArtist,
+		albumArtist: l.getArtistForScrobble(&s.MediaFile, model.RoleAlbumArtist, s.AlbumArtist),
 		timestamp:   s.TimeStamp,
 	})
 	if err == nil {

adapters/lastfm/agent_test.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"io"
 	"net/http"
+	"net/url"
 	"os"
 	"strconv"
 	"time"
@@ -38,12 +39,12 @@ var _ = Describe("lastfmAgent", func() {
 	})
 	Describe("lastFMConstructor", func() {
 		When("Agent is properly configured", func() {
-			It("uses configured api key and language", func() {
-				conf.Server.LastFM.Language = "pt"
+			It("uses configured api key and languages", func() {
+				conf.Server.LastFM.Languages = []string{"pt", "en"}
 				agent := lastFMConstructor(ds)
 				Expect(agent.apiKey).To(Equal("123"))
 				Expect(agent.secret).To(Equal("secret"))
-				Expect(agent.lang).To(Equal("pt"))
+				Expect(agent.languages).To(Equal([]string{"pt", "en"}))
 			})
 		})
 		When("Agent is disabled", func() {
@@ -71,7 +72,7 @@ var _ = Describe("lastfmAgent", func() {
 		var httpClient *tests.FakeHttpClient
 		BeforeEach(func() {
 			httpClient = &tests.FakeHttpClient{}
-			client := newClient("API_KEY", "SECRET", "pt", httpClient)
+			client := newClient("API_KEY", "SECRET", httpClient)
 			agent = lastFMConstructor(ds)
 			agent.client = client
 		})
@@ -101,12 +102,129 @@ var _ = Describe("lastfmAgent", func() {
 		})
 	})
 
+	Describe("Language Fallback", func() {
+		Describe("GetArtistBiography", func() {
+			var agent *lastfmAgent
+			var httpClient *langAwareHttpClient
+
+			BeforeEach(func() {
+				httpClient = newLangAwareHttpClient()
+			})
+
+			It("returns content in first language when available (1 API call)", func() {
+				conf.Server.LastFM.Languages = []string{"pt", "en"}
+				agent = lastFMConstructor(ds)
+				agent.client = newClient("API_KEY", "SECRET", httpClient)
+
+				// Portuguese biography available
+				f, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.json")
+				httpClient.responses["pt"] = http.Response{Body: f, StatusCode: 200}
+
+				bio, err := agent.GetArtistBiography(ctx, "123", "U2", "")
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(bio).To(ContainSubstring("U2 é uma das mais importantes bandas de rock"))
+				Expect(httpClient.requestCount).To(Equal(1))
+				Expect(httpClient.requests[0].URL.Query().Get("lang")).To(Equal("pt"))
+			})
+
+			It("falls back to second language when first returns empty (2 API calls)", func() {
+				conf.Server.LastFM.Languages = []string{"ja", "en"}
+				agent = lastFMConstructor(ds)
+				agent.client = newClient("API_KEY", "SECRET", httpClient)
+
+				// Japanese returns empty/ignored biography (actual Last.fm response with just "Read more" link)
+				fJa, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.empty.json")
+				httpClient.responses["ja"] = http.Response{Body: fJa, StatusCode: 200}
+				// English returns full biography
+				fEn, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.en.json")
+				httpClient.responses["en"] = http.Response{Body: fEn, StatusCode: 200}
+
+				bio, err := agent.GetArtistBiography(ctx, "123", "Legião Urbana", "")
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(bio).To(ContainSubstring("Legião Urbana was a Brazilian post-punk band"))
+				Expect(httpClient.requestCount).To(Equal(2))
+				Expect(httpClient.requests[0].URL.Query().Get("lang")).To(Equal("ja"))
+				Expect(httpClient.requests[1].URL.Query().Get("lang")).To(Equal("en"))
+			})
+
+			It("returns ErrNotFound when all languages return empty", func() {
+				conf.Server.LastFM.Languages = []string{"ja", "xx"}
+				agent = lastFMConstructor(ds)
+				agent.client = newClient("API_KEY", "SECRET", httpClient)
+
+				// Both languages return empty/ignored biography (using actual Last.fm response format)
+				fJa, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.empty.json")
+				httpClient.responses["ja"] = http.Response{Body: fJa, StatusCode: 200}
+				// Second language also returns empty
+				fXx, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.empty.json")
+				httpClient.responses["xx"] = http.Response{Body: fXx, StatusCode: 200}
+
+				_, err := agent.GetArtistBiography(ctx, "123", "Legião Urbana", "")
+
+				Expect(err).To(MatchError(agents.ErrNotFound))
+				Expect(httpClient.requestCount).To(Equal(2))
+			})
+		})
+
+		Describe("GetAlbumInfo", func() {
+			var agent *lastfmAgent
+			var httpClient *langAwareHttpClient
+
+			BeforeEach(func() {
+				httpClient = newLangAwareHttpClient()
+			})
+
+			It("falls back to second language when first returns empty description (2 API calls)", func() {
+				conf.Server.LastFM.Languages = []string{"ja", "en"}
+				agent = lastFMConstructor(ds)
+				agent.client = newClient("API_KEY", "SECRET", httpClient)
+
+				// Japanese returns album without wiki/description (actual Last.fm response)
+				fJa, _ := os.Open("tests/fixtures/lastfm.album.getinfo.empty.json")
+				httpClient.responses["ja"] = http.Response{Body: fJa, StatusCode: 200}
+				// English returns album with description
+				fEn, _ := os.Open("tests/fixtures/lastfm.album.getinfo.en.json")
+				httpClient.responses["en"] = http.Response{Body: fEn, StatusCode: 200}
+
+				albumInfo, err := agent.GetAlbumInfo(ctx, "Dois", "Legião Urbana", "")
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(albumInfo.Name).To(Equal("Dois"))
+				Expect(albumInfo.Description).To(ContainSubstring("segundo álbum de estúdio"))
+				Expect(httpClient.requestCount).To(Equal(2))
+				Expect(httpClient.requests[0].URL.Query().Get("lang")).To(Equal("ja"))
+				Expect(httpClient.requests[1].URL.Query().Get("lang")).To(Equal("en"))
+			})
+
+			It("returns album without description when all languages return empty", func() {
+				conf.Server.LastFM.Languages = []string{"ja", "xx"}
+				agent = lastFMConstructor(ds)
+				agent.client = newClient("API_KEY", "SECRET", httpClient)
+
+				// Both languages return album without description
+				fJa, _ := os.Open("tests/fixtures/lastfm.album.getinfo.empty.json")
+				httpClient.responses["ja"] = http.Response{Body: fJa, StatusCode: 200}
+				fXx, _ := os.Open("tests/fixtures/lastfm.album.getinfo.empty.json")
+				httpClient.responses["xx"] = http.Response{Body: fXx, StatusCode: 200}
+
+				albumInfo, err := agent.GetAlbumInfo(ctx, "Dois", "Legião Urbana", "")
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(albumInfo.Name).To(Equal("Dois"))
+				Expect(albumInfo.Description).To(BeEmpty())
+				Expect(httpClient.requestCount).To(Equal(2))
+			})
+		})
+	})
+
 	Describe("GetSimilarArtists", func() {
 		var agent *lastfmAgent
 		var httpClient *tests.FakeHttpClient
 		BeforeEach(func() {
 			httpClient = &tests.FakeHttpClient{}
-			client := newClient("API_KEY", "SECRET", "pt", httpClient)
+			client := newClient("API_KEY", "SECRET", httpClient)
 			agent = lastFMConstructor(ds)
 			agent.client = client
 		})
@@ -144,7 +262,7 @@ var _ = Describe("lastfmAgent", func() {
 		var httpClient *tests.FakeHttpClient
 		BeforeEach(func() {
 			httpClient = &tests.FakeHttpClient{}
-			client := newClient("API_KEY", "SECRET", "pt", httpClient)
+			client := newClient("API_KEY", "SECRET", httpClient)
 			agent = lastFMConstructor(ds)
 			agent.client = client
 		})
@@ -177,6 +295,54 @@ var _ = Describe("lastfmAgent", func() {
 		})
 	})
 
+	Describe("GetSimilarSongsByTrack", func() {
+		var agent *lastfmAgent
+		var httpClient *tests.FakeHttpClient
+		BeforeEach(func() {
+			httpClient = &tests.FakeHttpClient{}
+			client := newClient("API_KEY", "SECRET", httpClient)
+			agent = lastFMConstructor(ds)
+			agent.client = client
+		})
+
+		It("returns similar songs", func() {
+			f, _ := os.Open("tests/fixtures/lastfm.track.getsimilar.json")
+			httpClient.Res = http.Response{Body: f, StatusCode: 200}
+			Expect(agent.GetSimilarSongsByTrack(ctx, "123", "Just Can't Get Enough", "Depeche Mode", "", 5)).To(Equal([]agents.Song{
+				{Name: "Dreaming of Me", MBID: "027b553e-7c74-3ed4-a95e-1d4fea51f174", Artist: "Depeche Mode", ArtistMBID: "8538e728-ca0b-4321-b7e5-cff6565dd4c0"},
+				{Name: "Everything Counts", MBID: "5a5a3ca4-bdb8-4641-a674-9b54b9b319a6", Artist: "Depeche Mode", ArtistMBID: "8538e728-ca0b-4321-b7e5-cff6565dd4c0"},
+				{Name: "Don't You Want Me", MBID: "", Artist: "The Human League", ArtistMBID: "7adaabfb-acfb-47bc-8c7c-59471c2f0db8"},
+				{Name: "Tainted Love", MBID: "", Artist: "Soft Cell", ArtistMBID: "7fb50287-029d-47cc-825a-235ca28024b2"},
+				{Name: "Blue Monday", MBID: "727e84c6-1b56-31dd-a958-a5f46305cec0", Artist: "New Order", ArtistMBID: "f1106b17-dcbb-45f6-b938-199ccfab50cc"},
+			}))
+			Expect(httpClient.RequestCount).To(Equal(1))
+			Expect(httpClient.SavedRequest.URL.Query().Get("track")).To(Equal("Just Can't Get Enough"))
+			Expect(httpClient.SavedRequest.URL.Query().Get("artist")).To(Equal("Depeche Mode"))
+		})
+
+		It("returns ErrNotFound when no similar songs found", func() {
+			f, _ := os.Open("tests/fixtures/lastfm.track.getsimilar.unknown.json")
+			httpClient.Res = http.Response{Body: f, StatusCode: 200}
+			_, err := agent.GetSimilarSongsByTrack(ctx, "123", "UnknownTrack", "UnknownArtist", "", 3)
+			Expect(err).To(MatchError(agents.ErrNotFound))
+			Expect(httpClient.RequestCount).To(Equal(1))
+		})
+
+		It("returns an error if Last.fm call fails", func() {
+			httpClient.Err = errors.New("error")
+			_, err := agent.GetSimilarSongsByTrack(ctx, "123", "Believe", "Cher", "", 3)
+			Expect(err).To(HaveOccurred())
+			Expect(httpClient.RequestCount).To(Equal(1))
+		})
+
+		It("returns an error if Last.fm call returns an error", func() {
+			httpClient.Res = http.Response{Body: io.NopCloser(bytes.NewBufferString(lastfmError3)), StatusCode: 200}
+			_, err := agent.GetSimilarSongsByTrack(ctx, "123", "Believe", "Cher", "", 3)
+			Expect(err).To(HaveOccurred())
+			Expect(httpClient.RequestCount).To(Equal(1))
+		})
+	})
+
 	Describe("Scrobbling", func() {
 		var agent *lastfmAgent
 		var httpClient *tests.FakeHttpClient
@@ -184,7 +350,7 @@ var _ = Describe("lastfmAgent", func() {
 		BeforeEach(func() {
 			_ = ds.UserProps(ctx).Put("user-1", sessionKeyProperty, "SK-1")
 			httpClient = &tests.FakeHttpClient{}
-			client := newClient("API_KEY", "SECRET", "en", httpClient)
+			client := newClient("API_KEY", "SECRET", httpClient)
 			agent = lastFMConstructor(ds)
 			agent.client = client
 			track = &model.MediaFile{
@@ -201,6 +367,10 @@ var _ = Describe("lastfmAgent", func() {
 						{Artist: model.Artist{ID: "ar-1", Name: "First Artist"}},
 						{Artist: model.Artist{ID: "ar-2", Name: "Second Artist"}},
 					},
+					model.RoleAlbumArtist: []model.Participant{
+						{Artist: model.Artist{ID: "ar-1", Name: "First Album Artist"}},
+						{Artist: model.Artist{ID: "ar-2", Name: "Second Album Artist"}},
+					},
 				},
 			}
 		})
@@ -209,11 +379,12 @@ var _ = Describe("lastfmAgent", func() {
 			It("calls Last.fm with correct params", func() {
 				httpClient.Res = http.Response{Body: io.NopCloser(bytes.NewBufferString("{}")), StatusCode: 200}
 
-				err := agent.NowPlaying(ctx, "user-1", track)
+				err := agent.NowPlaying(ctx, "user-1", track, 0)
 
 				Expect(err).ToNot(HaveOccurred())
 				Expect(httpClient.SavedRequest.Method).To(Equal(http.MethodPost))
-				sentParams := httpClient.SavedRequest.URL.Query()
+				body, _ := io.ReadAll(httpClient.SavedRequest.Body)
+				sentParams, _ := url.ParseQuery(string(body))
 				Expect(sentParams.Get("method")).To(Equal("track.updateNowPlaying"))
 				Expect(sentParams.Get("sk")).To(Equal("SK-1"))
 				Expect(sentParams.Get("track")).To(Equal(track.Title))
@@ -226,9 +397,27 @@ var _ = Describe("lastfmAgent", func() {
 			})
 
 			It("returns ErrNotAuthorized if user is not linked", func() {
-				err := agent.NowPlaying(ctx, "user-2", track)
+				err := agent.NowPlaying(ctx, "user-2", track, 0)
 				Expect(err).To(MatchError(scrobbler.ErrNotAuthorized))
 			})
+
+			When("ScrobbleFirstArtistOnly is true", func() {
+				BeforeEach(func() {
+					conf.Server.LastFM.ScrobbleFirstArtistOnly = true
+				})
+
+				It("uses only the first artist", func() {
+					httpClient.Res = http.Response{Body: io.NopCloser(bytes.NewBufferString("{}")), StatusCode: 200}
+
+					err := agent.NowPlaying(ctx, "user-1", track, 0)
+
+					Expect(err).ToNot(HaveOccurred())
+					body, _ := io.ReadAll(httpClient.SavedRequest.Body)
+					sentParams, _ := url.ParseQuery(string(body))
+					Expect(sentParams.Get("artist")).To(Equal("First Artist"))
+					Expect(sentParams.Get("albumArtist")).To(Equal("First Album Artist"))
+				})
+			})
 		})
 
 		Describe("scrobble", func() {
@@ -240,7 +429,8 @@ var _ = Describe("lastfmAgent", func() {
 
 				Expect(err).ToNot(HaveOccurred())
 				Expect(httpClient.SavedRequest.Method).To(Equal(http.MethodPost))
-				sentParams := httpClient.SavedRequest.URL.Query()
+				body, _ := io.ReadAll(httpClient.SavedRequest.Body)
+				sentParams, _ := url.ParseQuery(string(body))
 				Expect(sentParams.Get("method")).To(Equal("track.scrobble"))
 				Expect(sentParams.Get("sk")).To(Equal("SK-1"))
 				Expect(sentParams.Get("track")).To(Equal(track.Title))
@@ -265,8 +455,10 @@ var _ = Describe("lastfmAgent", func() {
 					err := agent.Scrobble(ctx, "user-1", scrobbler.Scrobble{MediaFile: *track, TimeStamp: ts})
 
 					Expect(err).ToNot(HaveOccurred())
-					sentParams := httpClient.SavedRequest.URL.Query()
+					body, _ := io.ReadAll(httpClient.SavedRequest.Body)
+					sentParams, _ := url.ParseQuery(string(body))
 					Expect(sentParams.Get("artist")).To(Equal("First Artist"))
+					Expect(sentParams.Get("albumArtist")).To(Equal("First Album Artist"))
 				})
 			})
 
@@ -332,7 +524,7 @@ var _ = Describe("lastfmAgent", func() {
 		var httpClient *tests.FakeHttpClient
 		BeforeEach(func() {
 			httpClient = &tests.FakeHttpClient{}
-			client := newClient("API_KEY", "SECRET", "pt", httpClient)
+			client := newClient("API_KEY", "SECRET", httpClient)
 			agent = lastFMConstructor(ds)
 			agent.client = client
 		})
@@ -345,24 +537,6 @@ var _ = Describe("lastfmAgent", func() {
 				MBID:        "03c91c40-49a6-44a7-90e7-a700edf97a62",
 				Description: "Believe is the twenty-third studio album by American singer-actress Cher, released on November 10, 1998 by Warner Bros. Records. The RIAA certified it Quadruple Platinum on December 23, 1999, recognizing four million shipments in the United States; Worldwide, the album has sold more than 20 million copies, making it the biggest-selling album of her career. In 1999 the album received three Grammy Awards nominations including \"Record of the Year\", \"Best Pop Album\" and winning \"Best Dance Recording\" for the single \"Believe\". It was released by Warner Bros. Records at the end of 1998. The album was executive produced by Rob <a href=\"https://www.last.fm/music/Cher/Believe\">Read more on Last.fm</a>.",
 				URL:         "https://www.last.fm/music/Cher/Believe",
-				Images: []agents.ExternalImage{
-					{
-						URL:  "https://lastfm.freetls.fastly.net/i/u/34s/3b54885952161aaea4ce2965b2db1638.png",
-						Size: 34,
-					},
-					{
-						URL:  "https://lastfm.freetls.fastly.net/i/u/64s/3b54885952161aaea4ce2965b2db1638.png",
-						Size: 64,
-					},
-					{
-						URL:  "https://lastfm.freetls.fastly.net/i/u/174s/3b54885952161aaea4ce2965b2db1638.png",
-						Size: 174,
-					},
-					{
-						URL:  "https://lastfm.freetls.fastly.net/i/u/300x300/3b54885952161aaea4ce2965b2db1638.png",
-						Size: 300,
-					},
-				},
 			}))
 			Expect(httpClient.RequestCount).To(Equal(1))
 			Expect(httpClient.SavedRequest.URL.Query().Get("mbid")).To(Equal("03c91c40-49a6-44a7-90e7-a700edf97a62"))
@@ -372,9 +546,8 @@ var _ = Describe("lastfmAgent", func() {
 			f, _ := os.Open("tests/fixtures/lastfm.album.getinfo.empty_urls.json")
 			httpClient.Res = http.Response{Body: f, StatusCode: 200}
 			Expect(agent.GetAlbumInfo(ctx, "The Definitive Less Damage And More Joy", "The Jesus and Mary Chain", "")).To(Equal(&agents.AlbumInfo{
-				Name:   "The Definitive Less Damage And More Joy",
-				URL:    "https://www.last.fm/music/The+Jesus+and+Mary+Chain/The+Definitive+Less+Damage+And+More+Joy",
-				Images: []agents.ExternalImage{},
+				Name: "The Definitive Less Damage And More Joy",
+				URL:  "https://www.last.fm/music/The+Jesus+and+Mary+Chain/The+Definitive+Less+Damage+And+More+Joy",
 			}))
 			Expect(httpClient.RequestCount).To(Equal(1))
 			Expect(httpClient.SavedRequest.URL.Query().Get("album")).To(Equal("The Definitive Less Damage And More Joy"))
@@ -412,4 +585,101 @@ var _ = Describe("lastfmAgent", func() {
 			})
 		})
 	})
+
+	Describe("GetArtistImages", func() {
+		var agent *lastfmAgent
+		var apiClient *tests.FakeHttpClient
+		var httpClient *tests.FakeHttpClient
+
+		BeforeEach(func() {
+			apiClient = &tests.FakeHttpClient{}
+			httpClient = &tests.FakeHttpClient{}
+			client := newClient("API_KEY", "SECRET", apiClient)
+			agent = lastFMConstructor(ds)
+			agent.client = client
+			agent.httpClient = httpClient
+		})
+
+		It("returns the artist image from the page", func() {
+			fApi, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.json")
+			apiClient.Res = http.Response{Body: fApi, StatusCode: 200}
+
+			fScraper, _ := os.Open("tests/fixtures/lastfm.artist.page.html")
+			httpClient.Res = http.Response{Body: fScraper, StatusCode: 200}
+
+			images, err := agent.GetArtistImages(ctx, "123", "U2", "")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(images).To(HaveLen(1))
+			Expect(images[0].URL).To(Equal("https://lastfm.freetls.fastly.net/i/u/ar0/818148bf682d429dc21b59a73ef6f68e.png"))
+		})
+
+		It("returns empty list if image is the ignored default image", func() {
+			fApi, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.json")
+			apiClient.Res = http.Response{Body: fApi, StatusCode: 200}
+
+			fScraper, _ := os.Open("tests/fixtures/lastfm.artist.page.ignored.html")
+			httpClient.Res = http.Response{Body: fScraper, StatusCode: 200}
+
+			images, err := agent.GetArtistImages(ctx, "123", "U2", "")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(images).To(BeEmpty())
+		})
+
+		It("returns empty list if page has no meta tags", func() {
+			fApi, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.json")
+			apiClient.Res = http.Response{Body: fApi, StatusCode: 200}
+
+			fScraper, _ := os.Open("tests/fixtures/lastfm.artist.page.no_meta.html")
+			httpClient.Res = http.Response{Body: fScraper, StatusCode: 200}
+
+			images, err := agent.GetArtistImages(ctx, "123", "U2", "")
+			Expect(err).ToNot(HaveOccurred())
+			Expect(images).To(BeEmpty())
+		})
+
+		It("returns error if API call fails", func() {
+			apiClient.Err = errors.New("api error")
+			_, err := agent.GetArtistImages(ctx, "123", "U2", "")
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("get artist info"))
+		})
+
+		It("returns error if scraper call fails", func() {
+			fApi, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.json")
+			apiClient.Res = http.Response{Body: fApi, StatusCode: 200}
+
+			httpClient.Err = errors.New("scraper error")
+			_, err := agent.GetArtistImages(ctx, "123", "U2", "")
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("get artist url"))
+		})
+	})
 })
+
+// langAwareHttpClient is a mock HTTP client that returns different responses based on the lang parameter
+type langAwareHttpClient struct {
+	responses    map[string]http.Response
+	requests     []*http.Request
+	requestCount int
+}
+
+func newLangAwareHttpClient() *langAwareHttpClient {
+	return &langAwareHttpClient{
+		responses: make(map[string]http.Response),
+		requests:  make([]*http.Request, 0),
+	}
+}
+
+func (c *langAwareHttpClient) Do(req *http.Request) (*http.Response, error) {
+	c.requestCount++
+	c.requests = append(c.requests, req)
+	lang := req.URL.Query().Get("lang")
+	if resp, ok := c.responses[lang]; ok {
+		return &resp, nil
+	}
+	// Return default empty response if no specific response is configured
+	return &http.Response{
+		StatusCode: 200,
+		Body:       io.NopCloser(bytes.NewBufferString(`{}`)),
+	}, nil
+}

adapters/lastfm/auth_router.go

@@ -44,7 +44,7 @@ func NewRouter(ds model.DataStore) *Router {
 	hc := &http.Client{
 		Timeout: consts.DefaultHttpClientTimeOut,
 	}
-	r.client = newClient(r.apiKey, r.secret, "en", hc)
+	r.client = newClient(r.apiKey, r.secret, hc)
 	return r
 }
 

adapters/lastfm/client.go

@@ -34,24 +34,23 @@ type httpDoer interface {
 	Do(req *http.Request) (*http.Response, error)
 }
 
-func newClient(apiKey string, secret string, lang string, hc httpDoer) *client {
-	return &client{apiKey, secret, lang, hc}
+func newClient(apiKey string, secret string, hc httpDoer) *client {
+	return &client{apiKey, secret, hc}
 }
 
 type client struct {
 	apiKey string
 	secret string
-	lang   string
 	hc     httpDoer
 }
 
-func (c *client) albumGetInfo(ctx context.Context, name string, artist string, mbid string) (*Album, error) {
+func (c *client) albumGetInfo(ctx context.Context, name string, artist string, mbid string, lang string) (*Album, error) {
 	params := url.Values{}
 	params.Add("method", "album.getInfo")
 	params.Add("album", name)
 	params.Add("artist", artist)
 	params.Add("mbid", mbid)
-	params.Add("lang", c.lang)
+	params.Add("lang", lang)
 	response, err := c.makeRequest(ctx, http.MethodGet, params, false)
 	if err != nil {
 		return nil, err
@@ -59,11 +58,11 @@ func (c *client) albumGetInfo(ctx context.Context, name string, artist string, m
 	return &response.Album, nil
 }
 
-func (c *client) artistGetInfo(ctx context.Context, name string) (*Artist, error) {
+func (c *client) artistGetInfo(ctx context.Context, name string, lang string) (*Artist, error) {
 	params := url.Values{}
 	params.Add("method", "artist.getInfo")
 	params.Add("artist", name)
-	params.Add("lang", c.lang)
+	params.Add("lang", lang)
 	response, err := c.makeRequest(ctx, http.MethodGet, params, false)
 	if err != nil {
 		return nil, err
@@ -95,6 +94,19 @@ func (c *client) artistGetTopTracks(ctx context.Context, name string, limit int)
 	return &response.TopTracks, nil
 }
 
+func (c *client) trackGetSimilar(ctx context.Context, name, artist string, limit int) (*SimilarTracks, error) {
+	params := url.Values{}
+	params.Add("method", "track.getSimilar")
+	params.Add("track", name)
+	params.Add("artist", artist)
+	params.Add("limit", strconv.Itoa(limit))
+	response, err := c.makeRequest(ctx, http.MethodGet, params, false)
+	if err != nil {
+		return nil, err
+	}
+	return &response.SimilarTracks, nil
+}
+
 func (c *client) GetToken(ctx context.Context) (string, error) {
 	params := url.Values{}
 	params.Add("method", "auth.getToken")
@@ -185,8 +197,15 @@ func (c *client) makeRequest(ctx context.Context, method string, params url.Valu
 		c.sign(params)
 	}
 
-	req, _ := http.NewRequestWithContext(ctx, method, apiBaseUrl, nil)
-	req.URL.RawQuery = params.Encode()
+	var req *http.Request
+	if method == http.MethodPost {
+		body := strings.NewReader(params.Encode())
+		req, _ = http.NewRequestWithContext(ctx, method, apiBaseUrl, body)
+		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	} else {
+		req, _ = http.NewRequestWithContext(ctx, method, apiBaseUrl, nil)
+		req.URL.RawQuery = params.Encode()
+	}
 
 	log.Trace(ctx, fmt.Sprintf("Sending Last.fm %s request", req.Method), "url", req.URL)
 	resp, err := c.hc.Do(req)

adapters/lastfm/client_test.go

@@ -22,7 +22,7 @@ var _ = Describe("client", func() {
 
 	BeforeEach(func() {
 		httpClient = &tests.FakeHttpClient{}
-		client = newClient("API_KEY", "SECRET", "pt", httpClient)
+		client = newClient("API_KEY", "SECRET", httpClient)
 	})
 
 	Describe("albumGetInfo", func() {
@@ -30,7 +30,7 @@ var _ = Describe("client", func() {
 			f, _ := os.Open("tests/fixtures/lastfm.album.getinfo.json")
 			httpClient.Res = http.Response{Body: f, StatusCode: 200}
 
-			album, err := client.albumGetInfo(context.Background(), "Believe", "U2", "mbid-1234")
+			album, err := client.albumGetInfo(context.Background(), "Believe", "U2", "mbid-1234", "pt")
 			Expect(err).To(BeNil())
 			Expect(album.Name).To(Equal("Believe"))
 			Expect(httpClient.SavedRequest.URL.String()).To(Equal(apiBaseUrl + "?album=Believe&api_key=API_KEY&artist=U2&format=json&lang=pt&mbid=mbid-1234&method=album.getInfo"))
@@ -42,7 +42,7 @@ var _ = Describe("client", func() {
 			f, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.json")
 			httpClient.Res = http.Response{Body: f, StatusCode: 200}
 
-			artist, err := client.artistGetInfo(context.Background(), "U2")
+			artist, err := client.artistGetInfo(context.Background(), "U2", "pt")
 			Expect(err).To(BeNil())
 			Expect(artist.Name).To(Equal("U2"))
 			Expect(httpClient.SavedRequest.URL.String()).To(Equal(apiBaseUrl + "?api_key=API_KEY&artist=U2&format=json&lang=pt&method=artist.getInfo"))
@@ -54,7 +54,7 @@ var _ = Describe("client", func() {
 				StatusCode: 500,
 			}
 
-			_, err := client.artistGetInfo(context.Background(), "U2")
+			_, err := client.artistGetInfo(context.Background(), "U2", "pt")
 			Expect(err).To(MatchError("last.fm http status: (500)"))
 		})
 
@@ -64,7 +64,7 @@ var _ = Describe("client", func() {
 				StatusCode: 400,
 			}
 
-			_, err := client.artistGetInfo(context.Background(), "U2")
+			_, err := client.artistGetInfo(context.Background(), "U2", "pt")
 			Expect(err).To(MatchError(&lastFMError{Code: 3, Message: "Invalid Method - No method with that name in this package"}))
 		})
 
@@ -74,14 +74,14 @@ var _ = Describe("client", func() {
 				StatusCode: 200,
 			}
 
-			_, err := client.artistGetInfo(context.Background(), "U2")
+			_, err := client.artistGetInfo(context.Background(), "U2", "pt")
 			Expect(err).To(MatchError(&lastFMError{Code: 6, Message: "The artist you supplied could not be found"}))
 		})
 
 		It("fails if HttpClient.Do() returns error", func() {
 			httpClient.Err = errors.New("generic error")
 
-			_, err := client.artistGetInfo(context.Background(), "U2")
+			_, err := client.artistGetInfo(context.Background(), "U2", "pt")
 			Expect(err).To(MatchError("generic error"))
 		})
 
@@ -91,7 +91,7 @@ var _ = Describe("client", func() {
 				StatusCode: 200,
 			}
 
-			_, err := client.artistGetInfo(context.Background(), "U2")
+			_, err := client.artistGetInfo(context.Background(), "U2", "pt")
 			Expect(err).To(MatchError("invalid character '<' looking for beginning of value"))
 		})
 
@@ -121,6 +121,30 @@ var _ = Describe("client", func() {
 		})
 	})
 
+	Describe("trackGetSimilar", func() {
+		It("returns similar tracks for a successful response", func() {
+			f, _ := os.Open("tests/fixtures/lastfm.track.getsimilar.json")
+			httpClient.Res = http.Response{Body: f, StatusCode: 200}
+
+			similar, err := client.trackGetSimilar(context.Background(), "Just Can't Get Enough", "Depeche Mode", 5)
+			Expect(err).To(BeNil())
+			Expect(len(similar.Track)).To(Equal(5))
+			Expect(similar.Track[0].Name).To(Equal("Dreaming of Me"))
+			Expect(similar.Track[0].Artist.Name).To(Equal("Depeche Mode"))
+			Expect(similar.Track[0].Match).To(Equal(1.0))
+			Expect(httpClient.SavedRequest.URL.String()).To(Equal(apiBaseUrl + "?api_key=API_KEY&artist=Depeche+Mode&format=json&limit=5&method=track.getSimilar&track=Just+Can%27t+Get+Enough"))
+		})
+
+		It("returns empty list when no similar tracks found", func() {
+			f, _ := os.Open("tests/fixtures/lastfm.track.getsimilar.unknown.json")
+			httpClient.Res = http.Response{Body: f, StatusCode: 200}
+
+			similar, err := client.trackGetSimilar(context.Background(), "UnknownTrack", "UnknownArtist", 3)
+			Expect(err).To(BeNil())
+			Expect(similar.Track).To(BeEmpty())
+		})
+	})
+
 	Describe("GetToken", func() {
 		It("returns a token when the request is successful", func() {
 			httpClient.Res = http.Response{
@@ -154,6 +178,74 @@ var _ = Describe("client", func() {
 		})
 	})
 
+	Describe("scrobble", func() {
+		It("sends parameters in request body for POST", func() {
+			httpClient.Res = http.Response{
+				Body:       io.NopCloser(bytes.NewBufferString(`{"scrobbles":{"scrobble":{"ignoredMessage":{"code":"0"}},"@attr":{"accepted":1}}}`)),
+				StatusCode: 200,
+			}
+
+			info := ScrobbleInfo{
+				artist:      "U2",
+				track:       "One",
+				album:       "Achtung Baby",
+				trackNumber: 1,
+				duration:    276,
+				albumArtist: "U2",
+			}
+			err := client.scrobble(context.Background(), "SESSION_KEY", info)
+			Expect(err).To(BeNil())
+
+			req := httpClient.SavedRequest
+			Expect(req.Method).To(Equal(http.MethodPost))
+			Expect(req.Header.Get("Content-Type")).To(Equal("application/x-www-form-urlencoded"))
+			Expect(req.URL.RawQuery).To(BeEmpty())
+
+			body, _ := io.ReadAll(req.Body)
+			bodyParams, _ := url.ParseQuery(string(body))
+			Expect(bodyParams.Get("method")).To(Equal("track.scrobble"))
+			Expect(bodyParams.Get("artist")).To(Equal("U2"))
+			Expect(bodyParams.Get("track")).To(Equal("One"))
+			Expect(bodyParams.Get("sk")).To(Equal("SESSION_KEY"))
+			Expect(bodyParams.Get("api_key")).To(Equal("API_KEY"))
+			Expect(bodyParams.Get("api_sig")).ToNot(BeEmpty())
+		})
+	})
+
+	Describe("updateNowPlaying", func() {
+		It("sends parameters in request body for POST", func() {
+			httpClient.Res = http.Response{
+				Body:       io.NopCloser(bytes.NewBufferString(`{"nowplaying":{"ignoredMessage":{"code":"0"}}}`)),
+				StatusCode: 200,
+			}
+
+			info := ScrobbleInfo{
+				artist:      "U2",
+				track:       "One",
+				album:       "Achtung Baby",
+				trackNumber: 1,
+				duration:    276,
+				albumArtist: "U2",
+			}
+			err := client.updateNowPlaying(context.Background(), "SESSION_KEY", info)
+			Expect(err).To(BeNil())
+
+			req := httpClient.SavedRequest
+			Expect(req.Method).To(Equal(http.MethodPost))
+			Expect(req.Header.Get("Content-Type")).To(Equal("application/x-www-form-urlencoded"))
+			Expect(req.URL.RawQuery).To(BeEmpty())
+
+			body, _ := io.ReadAll(req.Body)
+			bodyParams, _ := url.ParseQuery(string(body))
+			Expect(bodyParams.Get("method")).To(Equal("track.updateNowPlaying"))
+			Expect(bodyParams.Get("artist")).To(Equal("U2"))
+			Expect(bodyParams.Get("track")).To(Equal("One"))
+			Expect(bodyParams.Get("sk")).To(Equal("SESSION_KEY"))
+			Expect(bodyParams.Get("api_key")).To(Equal("API_KEY"))
+			Expect(bodyParams.Get("api_sig")).ToNot(BeEmpty())
+		})
+	})
+
 	Describe("sign", func() {
 		It("adds an api_sig param with the signature", func() {
 			params := url.Values{}

adapters/lastfm/responses.go

@@ -5,6 +5,7 @@ type Response struct {
 	SimilarArtists SimilarArtists `json:"similarartists"`
 	TopTracks      TopTracks      `json:"toptracks"`
 	Album          Album          `json:"album"`
+	SimilarTracks  SimilarTracks  `json:"similartracks"`
 	Error          int            `json:"error"`
 	Message        string         `json:"message"`
 	Token          string         `json:"token"`
@@ -59,6 +60,28 @@ type TopTracks struct {
 	Attr  Attr    `json:"@attr"`
 }
 
+type SimilarTracks struct {
+	Track []SimilarTrack `json:"track"`
+	Attr  SimilarAttr    `json:"@attr"`
+}
+
+type SimilarTrack struct {
+	Name   string             `json:"name"`
+	MBID   string             `json:"mbid"`
+	Match  float64            `json:"match"`
+	Artist SimilarTrackArtist `json:"artist"`
+}
+
+type SimilarTrackArtist struct {
+	Name string `json:"name"`
+	MBID string `json:"mbid"`
+}
+
+type SimilarAttr struct {
+	Artist string `json:"artist"`
+	Track  string `json:"track"`
+}
+
 type Session struct {
 	Name       string `json:"name"`
 	Key        string `json:"key"`

adapters/listenbrainz/agent.go

@@ -73,7 +73,7 @@ func (l *listenBrainzAgent) formatListen(track *model.MediaFile) listenInfo {
 	return li
 }
 
-func (l *listenBrainzAgent) NowPlaying(ctx context.Context, userId string, track *model.MediaFile) error {
+func (l *listenBrainzAgent) NowPlaying(ctx context.Context, userId string, track *model.MediaFile, position int) error {
 	sk, err := l.sessionKeys.Get(ctx, userId)
 	if err != nil || sk == "" {
 		return errors.Join(err, scrobbler.ErrNotAuthorized)

adapters/listenbrainz/agent_test.go

@@ -79,12 +79,12 @@ var _ = Describe("listenBrainzAgent", func() {
 		It("updates NowPlaying successfully", func() {
 			httpClient.Res = http.Response{Body: io.NopCloser(bytes.NewBufferString(`{"status": "ok"}`)), StatusCode: 200}
 
-			err := agent.NowPlaying(ctx, "user-1", track)
+			err := agent.NowPlaying(ctx, "user-1", track, 0)
 			Expect(err).ToNot(HaveOccurred())
 		})
 
 		It("returns ErrNotAuthorized if user is not linked", func() {
-			err := agent.NowPlaying(ctx, "user-2", track)
+			err := agent.NowPlaying(ctx, "user-2", track, 0)
 			Expect(err).To(MatchError(scrobbler.ErrNotAuthorized))
 		})
 	})

adapters/taglib/end_to_end_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/djherbis/times"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/model/metadata"
+	"github.com/navidrome/navidrome/utils/gg"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
@@ -78,22 +79,112 @@ var _ = Describe("Extractor", func() {
 
 	var e *extractor
 
+	parseTestFile := func(path string) *model.MediaFile {
+		mds, err := e.Parse(path)
+		Expect(err).ToNot(HaveOccurred())
+
+		info, ok := mds[path]
+		Expect(ok).To(BeTrue())
+
+		fileInfo, err := os.Stat(path)
+		Expect(err).ToNot(HaveOccurred())
+		info.FileInfo = testFileInfo{FileInfo: fileInfo}
+
+		metadata := metadata.New(path, info)
+		mf := metadata.ToMediaFile(1, "folderID")
+		return &mf
+	}
+
 	BeforeEach(func() {
 		e = &extractor{}
 	})
 
+	Describe("ReplayGain", func() {
+		DescribeTable("test replaygain end-to-end", func(file string, trackGain, trackPeak, albumGain, albumPeak *float64) {
+			mf := parseTestFile("tests/fixtures/" + file)
+
+			Expect(mf.RGTrackGain).To(Equal(trackGain))
+			Expect(mf.RGTrackPeak).To(Equal(trackPeak))
+			Expect(mf.RGAlbumGain).To(Equal(albumGain))
+			Expect(mf.RGAlbumPeak).To(Equal(albumPeak))
+		},
+			Entry("mp3 with no replaygain", "no_replaygain.mp3", nil, nil, nil, nil),
+			Entry("mp3 with no zero replaygain", "zero_replaygain.mp3", gg.P(0.0), gg.P(1.0), gg.P(0.0), gg.P(1.0)),
+		)
+	})
+
+	Describe("lyrics", func() {
+		makeLyrics := func(code, secondLine string) model.Lyrics {
+			return model.Lyrics{
+				DisplayArtist: "",
+				DisplayTitle:  "",
+				Lang:          code,
+				Line: []model.Line{
+					{Start: gg.P(int64(0)), Value: "This is"},
+					{Start: gg.P(int64(2500)), Value: secondLine},
+				},
+				Offset: nil,
+				Synced: true,
+			}
+		}
+
+		It("should fetch both synced and unsynced lyrics in mixed flac", func() {
+			mf := parseTestFile("tests/fixtures/mixed-lyrics.flac")
+
+			lyrics, err := mf.StructuredLyrics()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(lyrics).To(HaveLen(2))
+
+			Expect(lyrics[0].Synced).To(BeTrue())
+			Expect(lyrics[1].Synced).To(BeFalse())
+		})
+
+		It("should handle mp3 with uslt and sylt", func() {
+			mf := parseTestFile("tests/fixtures/test.mp3")
+
+			lyrics, err := mf.StructuredLyrics()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(lyrics).To(HaveLen(4))
+
+			engSylt := makeLyrics("eng", "English SYLT")
+			engUslt := makeLyrics("eng", "English")
+			unsSylt := makeLyrics("xxx", "unspecified SYLT")
+			unsUslt := makeLyrics("xxx", "unspecified")
+
+			Expect(lyrics).To(ConsistOf(engSylt, engUslt, unsSylt, unsUslt))
+		})
+
+		DescribeTable("format-specific lyrics", func(file string, isId3 bool) {
+			mf := parseTestFile("tests/fixtures/" + file)
+
+			lyrics, err := mf.StructuredLyrics()
+			Expect(err).To(Not(HaveOccurred()))
+			Expect(lyrics).To(HaveLen(2))
+
+			unspec := makeLyrics("xxx", "unspecified")
+			eng := makeLyrics("xxx", "English")
+
+			if isId3 {
+				eng.Lang = "eng"
+			}
+
+			Expect(lyrics).To(Or(
+				Equal(model.LyricList{unspec, eng}),
+				Equal(model.LyricList{eng, unspec})))
+		},
+			Entry("flac", "test.flac", false),
+			Entry("m4a", "test.m4a", false),
+			Entry("ogg", "test.ogg", false),
+			Entry("wma", "test.wma", false),
+			Entry("wv", "test.wv", false),
+			Entry("wav", "test.wav", true),
+			Entry("aiff", "test.aiff", true),
+		)
+	})
+
 	Describe("Participants", func() {
 		DescribeTable("test tags consistent across formats", func(format string) {
-			path := "tests/fixtures/test." + format
-			mds, err := e.Parse(path)
-			Expect(err).ToNot(HaveOccurred())
-
-			info := mds[path]
-			fileInfo, _ := os.Stat(path)
-			info.FileInfo = testFileInfo{FileInfo: fileInfo}
-
-			metadata := metadata.New(path, info)
-			mf := metadata.ToMediaFile(1, "folderID")
+			mf := parseTestFile("tests/fixtures/test." + format)
 
 			for _, data := range roles {
 				role := data.Role
@@ -144,11 +235,40 @@ var _ = Describe("Extractor", func() {
 			Entry("FLAC format", "flac"),
 			Entry("M4a format", "m4a"),
 			Entry("OGG format", "ogg"),
-			Entry("WMA format", "wv"),
+			Entry("WV format", "wv"),
 
 			Entry("MP3 format", "mp3"),
 			Entry("WAV format", "wav"),
 			Entry("AIFF format", "aiff"),
 		)
+
+		It("should parse wma", func() {
+			mf := parseTestFile("tests/fixtures/test.wma")
+
+			for _, data := range roles {
+				role := data.Role
+				artists := data.ParticipantList
+				actual := mf.Participants[role]
+
+				// WMA has no Arranger role
+				if role == model.RoleArranger {
+					Expect(actual).To(HaveLen(0))
+					continue
+				}
+
+				Expect(actual).To(HaveLen(len(artists)), role.String())
+
+				// For some bizarre reason, the order is inverted. We also don't get
+				// sort names or MBIDs
+				for i := range artists {
+					idx := len(artists) - 1 - i
+
+					actualArtist := actual[i]
+					expectedArtist := artists[idx]
+
+					Expect(actualArtist.Name).To(Equal(expectedArtist.Name))
+				}
+			}
+		})
 	})
 })

adapters/taglib/taglib.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/core/storage/local"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model/metadata"
@@ -42,23 +43,21 @@ func (e extractor) extractMetadata(filePath string) (*metadata.Info, error) {
 
 	// Parse audio properties
 	ap := metadata.AudioProperties{}
-	if length, ok := tags["_lengthinmilliseconds"]; ok && len(length) > 0 {
-		millis, _ := strconv.Atoi(length[0])
-		if millis > 0 {
-			ap.Duration = (time.Millisecond * time.Duration(millis)).Round(time.Millisecond * 10)
-		}
-		delete(tags, "_lengthinmilliseconds")
-	}
-	parseProp := func(prop string, target *int) {
-		if value, ok := tags[prop]; ok && len(value) > 0 {
-			*target, _ = strconv.Atoi(value[0])
-			delete(tags, prop)
-		}
-	}
-	parseProp("_bitrate", &ap.BitRate)
-	parseProp("_channels", &ap.Channels)
-	parseProp("_samplerate", &ap.SampleRate)
-	parseProp("_bitspersample", &ap.BitDepth)
+	ap.BitRate = parseProp(tags, "__bitrate")
+	ap.Channels = parseProp(tags, "__channels")
+	ap.SampleRate = parseProp(tags, "__samplerate")
+	ap.BitDepth = parseProp(tags, "__bitspersample")
+	length := parseProp(tags, "__lengthinmilliseconds")
+	ap.Duration = (time.Millisecond * time.Duration(length)).Round(time.Millisecond * 10)
+
+	// Extract basic tags
+	parseBasicTag(tags, "__title", "title")
+	parseBasicTag(tags, "__artist", "artist")
+	parseBasicTag(tags, "__album", "album")
+	parseBasicTag(tags, "__comment", "comment")
+	parseBasicTag(tags, "__genre", "genre")
+	parseBasicTag(tags, "__year", "year")
+	parseBasicTag(tags, "__track", "tracknumber")
 
 	// Parse track/disc totals
 	parseTuple := func(prop string) {
@@ -106,6 +105,31 @@ var tiplMapping = map[string]string{
 	"DJ-mix":   "djmixer",
 }
 
+// parseProp parses a property from the tags map and sets it to the target integer.
+// It also deletes the property from the tags map after parsing.
+func parseProp(tags map[string][]string, prop string) int {
+	if value, ok := tags[prop]; ok && len(value) > 0 {
+		v, _ := strconv.Atoi(value[0])
+		delete(tags, prop)
+		return v
+	}
+	return 0
+}
+
+// parseBasicTag checks if a basic tag (like __title, __artist, etc.) exists in the tags map.
+// If it does, it moves the value to a more appropriate tag name (like title, artist, etc.),
+// and deletes the basic tag from the map. If the target tag already exists, it ignores the basic tag.
+func parseBasicTag(tags map[string][]string, basicName string, tagName string) {
+	basicValue := tags[basicName]
+	if len(basicValue) == 0 {
+		return
+	}
+	delete(tags, basicName)
+	if len(tags[tagName]) == 0 {
+		tags[tagName] = basicValue
+	}
+}
+
 // parseTIPL parses the ID3v2.4 TIPL frame string, which is received from TagLib in the format:
 //
 //	"arranger Andrew Powell engineer Chris Blair engineer Pat Stapley producer Eric Woolfson".
@@ -144,8 +168,11 @@ func parseTIPL(tags map[string][]string) {
 var _ local.Extractor = (*extractor)(nil)
 
 func init() {
-	local.RegisterExtractor("taglib", func(_ fs.FS, baseDir string) local.Extractor {
+	local.RegisterExtractor("legacy-taglib", func(_ fs.FS, baseDir string) local.Extractor {
 		// ignores fs, as taglib extractor only works with local files
 		return &extractor{baseDir}
 	})
+	conf.AddHook(func() {
+		log.Debug("TagLib version", "version", Version())
+	})
 }

adapters/taglib/taglib_test.go

@@ -80,12 +80,11 @@ var _ = Describe("Extractor", func() {
 			Expect(err).To(BeNil())
 			Expect(m.Tags).To(HaveKeyWithValue("fbpm", []string{"141.7"}))
 
-			// TabLib 1.12 returns 18, previous versions return 39.
+			// TagLib 1.12 returns 18, previous versions return 39.
 			// See https://github.com/taglib/taglib/commit/2f238921824741b2cfe6fbfbfc9701d9827ab06b
 			Expect(m.AudioProperties.BitRate).To(BeElementOf(18, 19, 39, 40, 43, 49))
 			Expect(m.AudioProperties.Channels).To(BeElementOf(2))
 			Expect(m.AudioProperties.SampleRate).To(BeElementOf(8000))
-			Expect(m.AudioProperties.SampleRate).To(BeElementOf(8000))
 			Expect(m.HasPicture).To(BeTrue())
 		})
 
@@ -106,7 +105,7 @@ var _ = Describe("Extractor", func() {
 
 				Expect(m.Tags).To(Or(
 					HaveKeyWithValue("replaygain_album_gain", []string{albumGain}),
-					HaveKeyWithValue("----:com.apple.itunes:replaygain_track_gain", []string{albumGain}),
+					HaveKeyWithValue("----:com.apple.itunes:replaygain_album_gain", []string{albumGain}),
 				))
 
 				Expect(m.Tags).To(Or(
@@ -179,7 +178,7 @@ var _ = Describe("Extractor", func() {
 			Entry("correctly parses wma/asf tags", "test.wma", "1.02s", 1, 44100, 16, "3.27 dB", "0.132914", "3.27 dB", "0.132914", false, true),
 
 			// ffmpeg -f lavfi -i "sine=frequency=800:duration=1" test.wv
-			Entry("correctly parses wv (wavpak) tags", "test.wv", "1s", 1, 44100, 16, "3.43 dB", "0.125061", "3.43 dB", "0.125061", false, false),
+			Entry("correctly parses wv (wavpak) tags", "test.wv", "1s", 1, 44100, 16, "3.43 dB", "0.125061", "3.43 dB", "0.125061", false, true),
 
 			// ffmpeg -f lavfi -i "sine=frequency=1000:duration=1" test.wav
 			Entry("correctly parses wav tags", "test.wav", "1s", 1, 44100, 16, "3.06 dB", "0.125056", "3.06 dB", "0.125056", true, true),

adapters/taglib/taglib_wrapper.cpp

@@ -1,6 +1,5 @@
 #include <stdlib.h>
 #include <string.h>
-#include <typeinfo>
 
 #define TAGLIB_STATIC
 #include <apeproperties.h>
@@ -46,31 +45,63 @@ int taglib_read(const FILENAME_CHAR_T *filename, unsigned long id) {
 
   // Add audio properties to the tags
   const TagLib::AudioProperties *props(f.audioProperties());
-  goPutInt(id, (char *)"_lengthinmilliseconds", props->lengthInMilliseconds());
-  goPutInt(id, (char *)"_bitrate", props->bitrate());
-  goPutInt(id, (char *)"_channels", props->channels());
-  goPutInt(id, (char *)"_samplerate", props->sampleRate());
+  goPutInt(id, (char *)"__lengthinmilliseconds", props->lengthInMilliseconds());
+  goPutInt(id, (char *)"__bitrate", props->bitrate());
+  goPutInt(id, (char *)"__channels", props->channels());
+  goPutInt(id, (char *)"__samplerate", props->sampleRate());
 
+  // Extract bits per sample for supported formats
+  int bitsPerSample = 0;
   if (const auto* apeProperties{ dynamic_cast<const TagLib::APE::Properties*>(props) })
-      goPutInt(id, (char *)"_bitspersample",  apeProperties->bitsPerSample());
-  if (const auto* asfProperties{ dynamic_cast<const TagLib::ASF::Properties*>(props) })
-      goPutInt(id, (char *)"_bitspersample",  asfProperties->bitsPerSample());
+      bitsPerSample = apeProperties->bitsPerSample();
+  else if (const auto* asfProperties{ dynamic_cast<const TagLib::ASF::Properties*>(props) })
+      bitsPerSample = asfProperties->bitsPerSample();
   else if (const auto* flacProperties{ dynamic_cast<const TagLib::FLAC::Properties*>(props) })
-      goPutInt(id, (char *)"_bitspersample",  flacProperties->bitsPerSample());
+      bitsPerSample = flacProperties->bitsPerSample();
   else if (const auto* mp4Properties{ dynamic_cast<const TagLib::MP4::Properties*>(props) })
-      goPutInt(id, (char *)"_bitspersample",  mp4Properties->bitsPerSample());
+      bitsPerSample = mp4Properties->bitsPerSample();
   else if (const auto* wavePackProperties{ dynamic_cast<const TagLib::WavPack::Properties*>(props) })
-      goPutInt(id, (char *)"_bitspersample",  wavePackProperties->bitsPerSample());
+      bitsPerSample = wavePackProperties->bitsPerSample();
   else if (const auto* aiffProperties{ dynamic_cast<const TagLib::RIFF::AIFF::Properties*>(props) })
-      goPutInt(id, (char *)"_bitspersample",  aiffProperties->bitsPerSample());
+      bitsPerSample = aiffProperties->bitsPerSample();
   else if (const auto* wavProperties{ dynamic_cast<const TagLib::RIFF::WAV::Properties*>(props) })
-      goPutInt(id, (char *)"_bitspersample",  wavProperties->bitsPerSample());
+      bitsPerSample = wavProperties->bitsPerSample();
   else if (const auto* dsfProperties{ dynamic_cast<const TagLib::DSF::Properties*>(props) })
-      goPutInt(id, (char *)"_bitspersample",  dsfProperties->bitsPerSample());
+      bitsPerSample = dsfProperties->bitsPerSample();
+  
+  if (bitsPerSample > 0) {
+      goPutInt(id, (char *)"__bitspersample", bitsPerSample);
+  }
 
   // Send all properties to the Go map
   TagLib::PropertyMap tags = f.file()->properties();
 
+  // Make sure at least the basic properties are extracted
+  TagLib::Tag *basic = f.file()->tag();
+  if (!basic->isEmpty()) {
+    if (!basic->title().isEmpty()) {
+      tags.insert("__title", basic->title());
+    }
+    if (!basic->artist().isEmpty()) {
+      tags.insert("__artist", basic->artist());
+    }
+    if (!basic->album().isEmpty()) {
+      tags.insert("__album", basic->album());
+    }
+    if (!basic->comment().isEmpty()) {
+      tags.insert("__comment", basic->comment());
+    }
+    if (!basic->genre().isEmpty()) {
+      tags.insert("__genre", basic->genre());
+    }
+    if (basic->year() > 0) {
+      tags.insert("__year", TagLib::String::number(basic->year()));
+    }
+    if (basic->track() > 0) {
+      tags.insert("__track", TagLib::String::number(basic->track()));
+    }
+  }
+
   TagLib::ID3v2::Tag *id3Tags = NULL;
 
   // Get some extended/non-standard ID3-only tags (ex: iTunes extended frames)
@@ -113,7 +144,7 @@ int taglib_read(const FILENAME_CHAR_T *filename, unsigned long id) {
             strncpy(language, bv.data(), 3);
           }
 
-          char *val = (char *)frame->text().toCString(true);
+          char *val = const_cast<char*>(frame->text().toCString(true));
 
           goPutLyrics(id, language, val);
         }
@@ -132,7 +163,7 @@ int taglib_read(const FILENAME_CHAR_T *filename, unsigned long id) {
           if (format == TagLib::ID3v2::SynchronizedLyricsFrame::AbsoluteMilliseconds) {
 
             for (const auto &line: frame->synchedText()) {
-              char *text = (char *)line.text.toCString(true);
+              char *text = const_cast<char*>(line.text.toCString(true));
               goPutLyricLine(id, language, text, line.time);
             }
           } else if (format == TagLib::ID3v2::SynchronizedLyricsFrame::AbsoluteMpegFrames) {
@@ -141,7 +172,7 @@ int taglib_read(const FILENAME_CHAR_T *filename, unsigned long id) {
             if (sampleRate != 0) {
               for (const auto &line: frame->synchedText()) {
                 const int timeInMs = (line.time * 1000) / sampleRate;
-                char *text = (char *)line.text.toCString(true);
+                char *text = const_cast<char*>(line.text.toCString(true));
                 goPutLyricLine(id, language, text, timeInMs);
               }
             }
@@ -160,9 +191,9 @@ int taglib_read(const FILENAME_CHAR_T *filename, unsigned long id) {
   if (m4afile != NULL) {
     const auto itemListMap = m4afile->tag()->itemMap();
     for (const auto item: itemListMap) {
-      char *key = (char *)item.first.toCString(true);
+      char *key = const_cast<char*>(item.first.toCString(true));
       for (const auto value: item.second.toStringList()) {
-        char *val = (char *)value.toCString(true);
+        char *val = const_cast<char*>(value.toCString(true));
         goPutM4AStr(id, key, val);
       }
     }
@@ -174,17 +205,24 @@ int taglib_read(const FILENAME_CHAR_T *filename, unsigned long id) {
     const TagLib::ASF::Tag *asfTags{asfFile->tag()};
     const auto itemListMap = asfTags->attributeListMap();
     for (const auto item : itemListMap) {
-      tags.insert(item.first, item.second.front().toString());
+      char *key = const_cast<char*>(item.first.toCString(true));
+
+      for (auto j = item.second.begin();
+           j != item.second.end(); ++j) {
+
+        char *val = const_cast<char*>(j->toString().toCString(true));
+        goPutStr(id, key, val);
+      }
     }
   }
 
   // Send all collected tags to the Go map
   for (TagLib::PropertyMap::ConstIterator i = tags.begin(); i != tags.end();
        ++i) {
-    char *key = (char *)i->first.toCString(true);
+    char *key = const_cast<char*>(i->first.toCString(true));
     for (TagLib::StringList::ConstIterator j = i->second.begin();
          j != i->second.end(); ++j) {
-      char *val = (char *)(*j).toCString(true);
+      char *val = const_cast<char*>((*j).toCString(true));
       goPutStr(id, key, val);
     }
   }
@@ -242,7 +280,19 @@ char has_cover(const TagLib::FileRef f) {
   // ----- WMA
   else if (TagLib::ASF::File * asfFile{dynamic_cast<TagLib::ASF::File *>(f.file())}) {
     const TagLib::ASF::Tag *tag{ asfFile->tag() };
-    hasCover = tag && asfFile->tag()->attributeListMap().contains("WM/Picture");
+    hasCover = tag && tag->attributeListMap().contains("WM/Picture");
+  }
+  // ----- DSF
+  else if (TagLib::DSF::File * dsffile{ dynamic_cast<TagLib::DSF::File *>(f.file())}) {
+    const TagLib::ID3v2::Tag *tag { dsffile->tag() };
+    hasCover = tag && !tag->frameListMap()["APIC"].isEmpty();
+  }
+  // ----- WAVPAK (APE tag)
+  else if (TagLib::WavPack::File * wvFile{dynamic_cast<TagLib::WavPack::File *>(f.file())}) {
+    if (wvFile->hasAPETag()) {
+      // This is the particular string that Picard uses
+      hasCover = !wvFile->APETag()->itemListMap()["COVER ART (FRONT)"].isEmpty();
+    }
   }
 
   return hasCover;

cmd/cmd_suite_test.go

@@ -0,0 +1,17 @@
+package cmd
+
+import (
+	"testing"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestCmd(t *testing.T) {
+	tests.Init(t, false)
+	log.SetLevel(log.LevelFatal)
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Cmd Suite")
+}

cmd/pls.go

@@ -10,11 +10,8 @@ import (
 	"strconv"
 
 	"github.com/Masterminds/squirrel"
-	"github.com/navidrome/navidrome/core/auth"
-	"github.com/navidrome/navidrome/db"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/persistence"
 	"github.com/spf13/cobra"
 )
 
@@ -52,7 +49,7 @@ var (
 		Short: "Export playlists",
 		Long:  "Export Navidrome playlists to M3U files",
 		Run: func(cmd *cobra.Command, args []string) {
-			runExporter()
+			runExporter(cmd.Context())
 		},
 	}
 
@@ -60,15 +57,13 @@ var (
 		Use:   "list",
 		Short: "List playlists",
 		Run: func(cmd *cobra.Command, args []string) {
-			runList()
+			runList(cmd.Context())
 		},
 	}
 )
 
-func runExporter() {
-	sqlDB := db.Db()
-	ds := persistence.New(sqlDB)
-	ctx := auth.WithAdminUser(context.Background(), ds)
+func runExporter(ctx context.Context) {
+	ds, ctx := getAdminContext(ctx)
 	playlist, err := ds.Playlist(ctx).GetWithTracks(playlistID, true, false)
 	if err != nil && !errors.Is(err, model.ErrNotFound) {
 		log.Fatal("Error retrieving playlist", "name", playlistID, err)
@@ -100,31 +95,19 @@ func runExporter() {
 	}
 }
 
-func runList() {
+func runList(ctx context.Context) {
 	if outputFormat != "csv" && outputFormat != "json" {
 		log.Fatal("Invalid output format. Must be one of csv, json", "format", outputFormat)
 	}
 
-	sqlDB := db.Db()
-	ds := persistence.New(sqlDB)
-	ctx := auth.WithAdminUser(context.Background(), ds)
-
+	ds, ctx := getAdminContext(ctx)
 	options := model.QueryOptions{Sort: "owner_name"}
 
 	if userID != "" {
-		user, err := ds.User(ctx).FindByUsername(userID)
-
-		if err != nil && !errors.Is(err, model.ErrNotFound) {
-			log.Fatal("Error retrieving user by name", "name", userID, err)
+		user, err := getUser(ctx, userID, ds)
+		if err != nil {
+			log.Fatal(ctx, "Error retrieving user", "username or id", userID)
 		}
-
-		if errors.Is(err, model.ErrNotFound) {
-			user, err = ds.User(ctx).Get(userID)
-			if err != nil {
-				log.Fatal("Error retrieving user by id", "id", userID, err)
-			}
-		}
-
 		options.Filters = squirrel.Eq{"owner_id": user.ID}
 	}
 

cmd/root.go

@@ -9,7 +9,6 @@ import (
 	"time"
 
 	"github.com/go-chi/chi/v5/middleware"
-	_ "github.com/navidrome/navidrome/adapters/taglib"
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/db"
@@ -22,6 +21,14 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"golang.org/x/sync/errgroup"
+
+	// Import adapters to register them
+	_ "github.com/navidrome/navidrome/adapters/deezer"
+	_ "github.com/navidrome/navidrome/adapters/gotaglib"
+	_ "github.com/navidrome/navidrome/adapters/lastfm"
+	_ "github.com/navidrome/navidrome/adapters/listenbrainz"
+	_ "github.com/navidrome/navidrome/adapters/spotify"
+	_ "github.com/navidrome/navidrome/adapters/taglib"
 )
 
 var (
@@ -82,8 +89,9 @@ func runNavidrome(ctx context.Context) {
 	g.Go(schedulePeriodicBackup(ctx))
 	g.Go(startInsightsCollector(ctx))
 	g.Go(scheduleDBOptimizer(ctx))
+	g.Go(startPluginManager(ctx))
+	g.Go(runInitialScan(ctx))
 	if conf.Server.Scanner.Enabled {
-		g.Go(runInitialScan(ctx))
 		g.Go(startScanWatcher(ctx))
 		g.Go(schedulePeriodicScan(ctx))
 	} else {
@@ -109,7 +117,7 @@ func mainContext(ctx context.Context) (context.Context, context.CancelFunc) {
 func startServer(ctx context.Context) func() error {
 	return func() error {
 		a := CreateServer()
-		a.MountRouter("Native API", consts.URLPathNativeAPI, CreateNativeAPIRouter())
+		a.MountRouter("Native API", consts.URLPathNativeAPI, CreateNativeAPIRouter(ctx))
 		a.MountRouter("Subsonic API", consts.URLPathSubsonicAPI, CreateSubsonicAPIRouter(ctx))
 		a.MountRouter("Public Endpoints", consts.URLPathPublic, CreatePublicRouter())
 		if conf.Server.LastFM.Enabled {
@@ -147,7 +155,7 @@ func schedulePeriodicScan(ctx context.Context) func() error {
 		schedulerInstance := scheduler.GetInstance()
 
 		log.Info("Scheduling periodic scan", "schedule", schedule)
-		err := schedulerInstance.Add(schedule, func() {
+		_, err := schedulerInstance.Add(schedule, func() {
 			_, err := s.ScanAll(ctx, false)
 			if err != nil {
 				log.Error(ctx, "Error executing periodic scan", err)
@@ -172,6 +180,7 @@ func pidHashChanged(ds model.DataStore) (bool, error) {
 	return !strings.EqualFold(pidAlbum, conf.Server.PID.Album) || !strings.EqualFold(pidTrack, conf.Server.PID.Track), nil
 }
 
+// runInitialScan runs an initial scan of the music library if needed.
 func runInitialScan(ctx context.Context) func() error {
 	return func() error {
 		ds := CreateDataStore()
@@ -190,7 +199,7 @@ func runInitialScan(ctx context.Context) func() error {
 		scanNeeded := conf.Server.Scanner.ScanOnStartup || inProgress || fullScanRequired == "1" || pidHasChanged
 		time.Sleep(2 * time.Second) // Wait 2 seconds before the initial scan
 		if scanNeeded {
-			scanner := CreateScanner(ctx)
+			s := CreateScanner(ctx)
 			switch {
 			case fullScanRequired == "1":
 				log.Warn(ctx, "Full scan required after migration")
@@ -204,7 +213,7 @@ func runInitialScan(ctx context.Context) func() error {
 				log.Info("Executing initial scan")
 			}
 
-			_, err = scanner.ScanAll(ctx, fullScanRequired == "1")
+			_, err = s.ScanAll(ctx, fullScanRequired == "1")
 			if err != nil {
 				log.Error(ctx, "Scan failed", err)
 			} else {
@@ -243,7 +252,7 @@ func schedulePeriodicBackup(ctx context.Context) func() error {
 		schedulerInstance := scheduler.GetInstance()
 
 		log.Info("Scheduling periodic backup", "schedule", schedule)
-		err := schedulerInstance.Add(schedule, func() {
+		_, err := schedulerInstance.Add(schedule, func() {
 			start := time.Now()
 			path, err := db.Backup(ctx)
 			elapsed := time.Since(start)
@@ -271,7 +280,7 @@ func scheduleDBOptimizer(ctx context.Context) func() error {
 	return func() error {
 		log.Info(ctx, "Scheduling DB optimizer", "schedule", consts.OptimizeDBSchedule)
 		schedulerInstance := scheduler.GetInstance()
-		err := schedulerInstance.Add(consts.OptimizeDBSchedule, func() {
+		_, err := schedulerInstance.Add(consts.OptimizeDBSchedule, func() {
 			if scanner.IsScanning() {
 				log.Debug(ctx, "Skipping DB optimization because a scan is in progress")
 				return
@@ -325,10 +334,23 @@ func startPlaybackServer(ctx context.Context) func() error {
 	}
 }
 
+// startPluginManager starts the plugin manager, if configured.
+func startPluginManager(ctx context.Context) func() error {
+	return func() error {
+		manager := GetPluginManager(ctx)
+		if !conf.Server.Plugins.Enabled {
+			log.Debug("Plugin system is DISABLED")
+			return nil
+		}
+		log.Info(ctx, "Starting plugin manager")
+		return manager.Start(ctx)
+	}
+}
+
 // TODO: Implement some struct tags to map flags to viper
 func init() {
 	cobra.OnInitialize(func() {
-		conf.InitConfig(cfgFile)
+		conf.InitConfig(cfgFile, true)
 	})
 
 	rootCmd.PersistentFlags().StringVarP(&cfgFile, "configfile", "c", "", `config file (default "./navidrome.toml")`)
@@ -356,6 +378,7 @@ func init() {
 	rootCmd.Flags().Duration("scaninterval", viper.GetDuration("scaninterval"), "how frequently to scan for changes in your music library")
 	rootCmd.Flags().String("uiloginbackgroundurl", viper.GetString("uiloginbackgroundurl"), "URL to a backaground image used in the Login page")
 	rootCmd.Flags().Bool("enabletranscodingconfig", viper.GetBool("enabletranscodingconfig"), "enables transcoding configuration in the UI")
+	rootCmd.Flags().Bool("enabletranscodingcancellation", viper.GetBool("enabletranscodingcancellation"), "enables transcoding context cancellation")
 	rootCmd.Flags().String("transcodingcachesize", viper.GetString("transcodingcachesize"), "size of transcoding cache")
 	rootCmd.Flags().String("imagecachesize", viper.GetString("imagecachesize"), "size of image (art work) cache. set to 0 to disable cache")
 	rootCmd.Flags().String("albumplaycountmode", viper.GetString("albumplaycountmode"), "how to compute playcount for albums. absolute (default) or normalized")
@@ -379,6 +402,7 @@ func init() {
 	_ = viper.BindPFlag("prometheus.metricspath", rootCmd.Flags().Lookup("prometheus.metricspath"))
 
 	_ = viper.BindPFlag("enabletranscodingconfig", rootCmd.Flags().Lookup("enabletranscodingconfig"))
+	_ = viper.BindPFlag("enabletranscodingcancellation", rootCmd.Flags().Lookup("enabletranscodingcancellation"))
 	_ = viper.BindPFlag("transcodingcachesize", rootCmd.Flags().Lookup("transcodingcachesize"))
 	_ = viper.BindPFlag("imagecachesize", rootCmd.Flags().Lookup("imagecachesize"))
 }

cmd/scan.go

@@ -1,15 +1,17 @@
 package cmd
 
 import (
+	"bufio"
 	"context"
 	"encoding/gob"
+	"fmt"
 	"os"
+	"strings"
 
 	"github.com/navidrome/navidrome/core"
-	"github.com/navidrome/navidrome/core/artwork"
-	"github.com/navidrome/navidrome/core/metrics"
 	"github.com/navidrome/navidrome/db"
 	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/persistence"
 	"github.com/navidrome/navidrome/scanner"
 	"github.com/navidrome/navidrome/utils/pl"
@@ -19,11 +21,15 @@ import (
 var (
 	fullScan   bool
 	subprocess bool
+	targets    []string
+	targetFile string
 )
 
 func init() {
 	scanCmd.Flags().BoolVarP(&fullScan, "full", "f", false, "check all subfolders, ignoring timestamps")
 	scanCmd.Flags().BoolVarP(&subprocess, "subprocess", "", false, "run as subprocess (internal use)")
+	scanCmd.Flags().StringArrayVarP(&targets, "target", "t", []string{}, "list of libraryID:folderPath pairs, can be repeated (e.g., \"-t 1:Music/Rock -t 1:Music/Jazz -t 2:Classical\")")
+	scanCmd.Flags().StringVar(&targetFile, "target-file", "", "path to file containing targets (one libraryID:folderPath per line)")
 	rootCmd.AddCommand(scanCmd)
 }
 
@@ -70,7 +76,25 @@ func runScanner(ctx context.Context) {
 	ds := persistence.New(sqlDB)
 	pls := core.NewPlaylists(ds)
 
-	progress, err := scanner.CallScan(ctx, ds, artwork.NoopCacheWarmer(), pls, metrics.NewNoopInstance(), fullScan)
+	// Parse targets from command line or file
+	var scanTargets []model.ScanTarget
+	var err error
+
+	if targetFile != "" {
+		scanTargets, err = readTargetsFromFile(targetFile)
+		if err != nil {
+			log.Fatal(ctx, "Failed to read targets from file", err)
+		}
+		log.Info(ctx, "Scanning specific folders from file", "numTargets", len(scanTargets))
+	} else if len(targets) > 0 {
+		scanTargets, err = model.ParseTargets(targets)
+		if err != nil {
+			log.Fatal(ctx, "Failed to parse targets", err)
+		}
+		log.Info(ctx, "Scanning specific folders", "numTargets", len(scanTargets))
+	}
+
+	progress, err := scanner.CallScan(ctx, ds, pls, fullScan, scanTargets)
 	if err != nil {
 		log.Fatal(ctx, "Failed to scan", err)
 	}
@@ -82,3 +106,31 @@ func runScanner(ctx context.Context) {
 		trackScanInteractively(ctx, progress)
 	}
 }
+
+// readTargetsFromFile reads scan targets from a file, one per line.
+// Each line should be in the format "libraryID:folderPath".
+// Empty lines and lines starting with # are ignored.
+func readTargetsFromFile(filePath string) ([]model.ScanTarget, error) {
+	file, err := os.Open(filePath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open target file: %w", err)
+	}
+	defer file.Close()
+
+	var targetStrings []string
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		// Skip empty lines and comments
+		if line == "" {
+			continue
+		}
+		targetStrings = append(targetStrings, line)
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("failed to read target file: %w", err)
+	}
+
+	return model.ParseTargets(targetStrings)
+}

cmd/scan_test.go

@@ -0,0 +1,89 @@
+package cmd
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/navidrome/navidrome/model"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("readTargetsFromFile", func() {
+	var tempDir string
+
+	BeforeEach(func() {
+		var err error
+		tempDir, err = os.MkdirTemp("", "navidrome-test-")
+		Expect(err).ToNot(HaveOccurred())
+	})
+
+	AfterEach(func() {
+		os.RemoveAll(tempDir)
+	})
+
+	It("reads valid targets from file", func() {
+		filePath := filepath.Join(tempDir, "targets.txt")
+		content := "1:Music/Rock\n2:Music/Jazz\n3:Classical\n"
+		err := os.WriteFile(filePath, []byte(content), 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		targets, err := readTargetsFromFile(filePath)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(3))
+		Expect(targets[0]).To(Equal(model.ScanTarget{LibraryID: 1, FolderPath: "Music/Rock"}))
+		Expect(targets[1]).To(Equal(model.ScanTarget{LibraryID: 2, FolderPath: "Music/Jazz"}))
+		Expect(targets[2]).To(Equal(model.ScanTarget{LibraryID: 3, FolderPath: "Classical"}))
+	})
+
+	It("skips empty lines", func() {
+		filePath := filepath.Join(tempDir, "targets.txt")
+		content := "1:Music/Rock\n\n2:Music/Jazz\n\n"
+		err := os.WriteFile(filePath, []byte(content), 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		targets, err := readTargetsFromFile(filePath)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(2))
+	})
+
+	It("trims whitespace", func() {
+		filePath := filepath.Join(tempDir, "targets.txt")
+		content := "  1:Music/Rock  \n\t2:Music/Jazz\t\n"
+		err := os.WriteFile(filePath, []byte(content), 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		targets, err := readTargetsFromFile(filePath)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(2))
+		Expect(targets[0].FolderPath).To(Equal("Music/Rock"))
+		Expect(targets[1].FolderPath).To(Equal("Music/Jazz"))
+	})
+
+	It("returns error for non-existent file", func() {
+		_, err := readTargetsFromFile("/nonexistent/file.txt")
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("failed to open target file"))
+	})
+
+	It("returns error for invalid target format", func() {
+		filePath := filepath.Join(tempDir, "targets.txt")
+		content := "invalid-format\n"
+		err := os.WriteFile(filePath, []byte(content), 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		_, err = readTargetsFromFile(filePath)
+		Expect(err).To(HaveOccurred())
+	})
+
+	It("handles mixed valid and empty lines", func() {
+		filePath := filepath.Join(tempDir, "targets.txt")
+		content := "\n1:Music/Rock\n\n\n2:Music/Jazz\n\n"
+		err := os.WriteFile(filePath, []byte(content), 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		targets, err := readTargetsFromFile(filePath)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(2))
+	})
+})

cmd/user.go

@@ -0,0 +1,477 @@
+package cmd
+
+import (
+	"context"
+	"encoding/csv"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/Masterminds/squirrel"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/spf13/cobra"
+	"golang.org/x/term"
+)
+
+var (
+	email      string
+	libraryIds []int
+	name       string
+
+	removeEmail    bool
+	removeName     bool
+	setAdmin       bool
+	setPassword    bool
+	setRegularUser bool
+)
+
+func init() {
+	rootCmd.AddCommand(userRoot)
+
+	userCreateCommand.Flags().StringVarP(&userID, "username", "u", "", "username")
+
+	userCreateCommand.Flags().StringVarP(&email, "email", "e", "", "New user email")
+	userCreateCommand.Flags().IntSliceVarP(&libraryIds, "library-ids", "i", []int{}, "Comma-separated list of library IDs. Set the user's accessible libraries. If empty, the user can access all libraries. This is incompatible with admin, as admin can always access all libraries")
+
+	userCreateCommand.Flags().BoolVarP(&setAdmin, "admin", "a", false, "If set, make the user an admin. This user will have access to every library")
+	userCreateCommand.Flags().StringVar(&name, "name", "", "New user's name (this is separate from username used to log in)")
+
+	_ = userCreateCommand.MarkFlagRequired("username")
+
+	userRoot.AddCommand(userCreateCommand)
+
+	userDeleteCommand.Flags().StringVarP(&userID, "user", "u", "", "username or id")
+	_ = userDeleteCommand.MarkFlagRequired("user")
+	userRoot.AddCommand(userDeleteCommand)
+
+	userEditCommand.Flags().StringVarP(&userID, "user", "u", "", "username or id")
+
+	userEditCommand.Flags().BoolVar(&setAdmin, "set-admin", false, "If set, make the user an admin")
+	userEditCommand.Flags().BoolVar(&setRegularUser, "set-regular", false, "If set, make the user a non-admin")
+	userEditCommand.MarkFlagsMutuallyExclusive("set-admin", "set-regular")
+
+	userEditCommand.Flags().BoolVar(&removeEmail, "remove-email", false, "If set, clear the user's email")
+	userEditCommand.Flags().StringVarP(&email, "email", "e", "", "New user email")
+	userEditCommand.MarkFlagsMutuallyExclusive("email", "remove-email")
+
+	userEditCommand.Flags().BoolVar(&removeName, "remove-name", false, "If set, clear the user's name")
+	userEditCommand.Flags().StringVar(&name, "name", "", "New user name (this is separate from username used to log in)")
+	userEditCommand.MarkFlagsMutuallyExclusive("name", "remove-name")
+
+	userEditCommand.Flags().BoolVar(&setPassword, "set-password", false, "If set, the user's new password will be prompted on the CLI")
+
+	userEditCommand.Flags().IntSliceVarP(&libraryIds, "library-ids", "i", []int{}, "Comma-separated list of library IDs. Set the user's accessible libraries by id")
+
+	_ = userEditCommand.MarkFlagRequired("user")
+	userRoot.AddCommand(userEditCommand)
+
+	userListCommand.Flags().StringVarP(&outputFormat, "format", "f", "csv", "output format [supported values: csv, json]")
+	userRoot.AddCommand(userListCommand)
+}
+
+var (
+	userRoot = &cobra.Command{
+		Use:   "user",
+		Short: "Administer users",
+		Long:  "Create, delete, list, or update users",
+	}
+
+	userCreateCommand = &cobra.Command{
+		Use:     "create",
+		Aliases: []string{"c"},
+		Short:   "Create a new user",
+		Run: func(cmd *cobra.Command, args []string) {
+			runCreateUser(cmd.Context())
+		},
+	}
+
+	userDeleteCommand = &cobra.Command{
+		Use:     "delete",
+		Aliases: []string{"d"},
+		Short:   "Deletes an existing user",
+		Run: func(cmd *cobra.Command, args []string) {
+			runDeleteUser(cmd.Context())
+		},
+	}
+
+	userEditCommand = &cobra.Command{
+		Use:     "edit",
+		Aliases: []string{"e"},
+		Short:   "Edit a user",
+		Long:    "Edit the password, admin status, and/or library access",
+		Run: func(cmd *cobra.Command, args []string) {
+			runUserEdit(cmd.Context())
+		},
+	}
+
+	userListCommand = &cobra.Command{
+		Use:   "list",
+		Short: "List users",
+		Run: func(cmd *cobra.Command, args []string) {
+			runUserList(cmd.Context())
+		},
+	}
+)
+
+func promptPassword() string {
+	for {
+		fmt.Print("Enter new password (press enter with no password to cancel): ")
+		// This cast is necessary for some platforms
+		password, err := term.ReadPassword(int(syscall.Stdin)) //nolint:unconvert
+
+		if err != nil {
+			log.Fatal("Error getting password", err)
+		}
+
+		fmt.Print("\nConfirm new password (press enter with no password to cancel): ")
+		confirmation, err := term.ReadPassword(int(syscall.Stdin)) //nolint:unconvert
+
+		if err != nil {
+			log.Fatal("Error getting password confirmation", err)
+		}
+
+		// clear the line.
+		fmt.Println()
+
+		pass := string(password)
+		confirm := string(confirmation)
+
+		if pass == "" {
+			return ""
+		}
+
+		if pass == confirm {
+			return pass
+		}
+
+		fmt.Println("Password and password confirmation do not match")
+	}
+}
+
+func libraryError(libraries model.Libraries) error {
+	ids := make([]int, len(libraries))
+	for idx, library := range libraries {
+		ids[idx] = library.ID
+	}
+	return fmt.Errorf("not all available libraries found. Requested ids: %v, Found libraries: %v", libraryIds, ids)
+}
+
+func runCreateUser(ctx context.Context) {
+	password := promptPassword()
+	if password == "" {
+		log.Fatal("Empty password provided, user creation cancelled")
+	}
+
+	user := model.User{
+		UserName:    userID,
+		Email:       email,
+		Name:        name,
+		IsAdmin:     setAdmin,
+		NewPassword: password,
+	}
+
+	if user.Name == "" {
+		user.Name = userID
+	}
+
+	ds, ctx := getAdminContext(ctx)
+
+	err := ds.WithTx(func(tx model.DataStore) error {
+		existingUser, err := tx.User(ctx).FindByUsername(userID)
+		if existingUser != nil {
+			return fmt.Errorf("existing user '%s'", userID)
+		}
+
+		if err != nil && !errors.Is(err, model.ErrNotFound) {
+			return fmt.Errorf("failed to check existing username: %w", err)
+		}
+
+		if len(libraryIds) > 0 && !setAdmin {
+			user.Libraries, err = tx.Library(ctx).GetAll(model.QueryOptions{Filters: squirrel.Eq{"id": libraryIds}})
+			if err != nil {
+				return err
+			}
+
+			if len(user.Libraries) != len(libraryIds) {
+				return libraryError(user.Libraries)
+			}
+		} else {
+			user.Libraries, err = tx.Library(ctx).GetAll()
+			if err != nil {
+				return err
+			}
+		}
+
+		err = tx.User(ctx).Put(&user)
+		if err != nil {
+			return err
+		}
+
+		updatedIds := make([]int, len(user.Libraries))
+		for idx, lib := range user.Libraries {
+			updatedIds[idx] = lib.ID
+		}
+
+		err = tx.User(ctx).SetUserLibraries(user.ID, updatedIds)
+		return err
+	})
+
+	if err != nil {
+		log.Fatal(ctx, err)
+	}
+
+	log.Info(ctx, "Successfully created user", "id", user.ID, "username", user.UserName)
+}
+
+func runDeleteUser(ctx context.Context) {
+	ds, ctx := getAdminContext(ctx)
+
+	var err error
+	var user *model.User
+
+	err = ds.WithTx(func(tx model.DataStore) error {
+		count, err := tx.User(ctx).CountAll()
+		if err != nil {
+			return err
+		}
+
+		if count == 1 {
+			return errors.New("refusing to delete the last user")
+		}
+
+		user, err = getUser(ctx, userID, tx)
+		if err != nil {
+			return err
+		}
+
+		return tx.User(ctx).Delete(user.ID)
+	})
+
+	if err != nil {
+		log.Fatal(ctx, "Failed to delete user", err)
+	}
+
+	log.Info(ctx, "Deleted user", "username", user.UserName)
+}
+
+func runUserEdit(ctx context.Context) {
+	ds, ctx := getAdminContext(ctx)
+
+	var err error
+	var user *model.User
+	changes := []string{}
+
+	err = ds.WithTx(func(tx model.DataStore) error {
+		var newLibraries model.Libraries
+
+		user, err = getUser(ctx, userID, tx)
+		if err != nil {
+			return err
+		}
+
+		if len(libraryIds) > 0 && !setAdmin {
+			libraries, err := tx.Library(ctx).GetAll(model.QueryOptions{Filters: squirrel.Eq{"id": libraryIds}})
+
+			if err != nil {
+				return err
+			}
+
+			if len(libraries) != len(libraryIds) {
+				return libraryError(libraries)
+			}
+
+			newLibraries = libraries
+			changes = append(changes, "updated library ids")
+		}
+
+		if setAdmin && !user.IsAdmin {
+			libraries, err := tx.Library(ctx).GetAll()
+			if err != nil {
+				return err
+			}
+
+			user.IsAdmin = true
+			user.Libraries = libraries
+			changes = append(changes, "set admin")
+
+			newLibraries = libraries
+		}
+
+		if setRegularUser && user.IsAdmin {
+			user.IsAdmin = false
+			changes = append(changes, "set regular user")
+		}
+
+		if setPassword {
+			password := promptPassword()
+
+			if password != "" {
+				user.NewPassword = password
+				changes = append(changes, "updated password")
+			}
+		}
+
+		if email != "" && email != user.Email {
+			user.Email = email
+			changes = append(changes, "updated email")
+		} else if removeEmail && user.Email != "" {
+			user.Email = ""
+			changes = append(changes, "removed email")
+		}
+
+		if name != "" && name != user.Name {
+			user.Name = name
+			changes = append(changes, "updated name")
+		} else if removeName && user.Name != "" {
+			user.Name = ""
+			changes = append(changes, "removed name")
+		}
+
+		if len(changes) == 0 {
+			return nil
+		}
+
+		err := tx.User(ctx).Put(user)
+		if err != nil {
+			return err
+		}
+
+		if len(newLibraries) > 0 {
+			updatedIds := make([]int, len(newLibraries))
+			for idx, lib := range newLibraries {
+				updatedIds[idx] = lib.ID
+			}
+
+			err := tx.User(ctx).SetUserLibraries(user.ID, updatedIds)
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		log.Fatal(ctx, "Failed to update user", err)
+	}
+
+	if len(changes) == 0 {
+		log.Info(ctx, "No changes for user", "user", user.UserName)
+	} else {
+		log.Info(ctx, "Updated user", "user", user.UserName, "changes", strings.Join(changes, ", "))
+	}
+}
+
+type displayLibrary struct {
+	ID   int    `json:"id"`
+	Path string `json:"path"`
+}
+
+type displayUser struct {
+	Id         string           `json:"id"`
+	Username   string           `json:"username"`
+	Name       string           `json:"name"`
+	Email      string           `json:"email"`
+	Admin      bool             `json:"admin"`
+	CreatedAt  time.Time        `json:"createdAt"`
+	UpdatedAt  time.Time        `json:"updatedAt"`
+	LastAccess *time.Time       `json:"lastAccess"`
+	LastLogin  *time.Time       `json:"lastLogin"`
+	Libraries  []displayLibrary `json:"libraries"`
+}
+
+func runUserList(ctx context.Context) {
+	if outputFormat != "csv" && outputFormat != "json" {
+		log.Fatal("Invalid output format. Must be one of csv, json", "format", outputFormat)
+	}
+
+	ds, ctx := getAdminContext(ctx)
+
+	users, err := ds.User(ctx).ReadAll()
+	if err != nil {
+		log.Fatal(ctx, "Failed to retrieve users", err)
+	}
+
+	userList := users.(model.Users)
+
+	if outputFormat == "csv" {
+		w := csv.NewWriter(os.Stdout)
+		_ = w.Write([]string{
+			"user id",
+			"username",
+			"user's name",
+			"user email",
+			"admin",
+			"created at",
+			"updated at",
+			"last access",
+			"last login",
+			"libraries",
+		})
+		for _, user := range userList {
+			paths := make([]string, len(user.Libraries))
+
+			for idx, library := range user.Libraries {
+				paths[idx] = fmt.Sprintf("%d:%s", library.ID, library.Path)
+			}
+
+			var lastAccess, lastLogin string
+
+			if user.LastAccessAt != nil {
+				lastAccess = user.LastAccessAt.Format(time.RFC3339Nano)
+			} else {
+				lastAccess = "never"
+			}
+
+			if user.LastLoginAt != nil {
+				lastLogin = user.LastLoginAt.Format(time.RFC3339Nano)
+			} else {
+				lastLogin = "never"
+			}
+
+			_ = w.Write([]string{
+				user.ID,
+				user.UserName,
+				user.Name,
+				user.Email,
+				strconv.FormatBool(user.IsAdmin),
+				user.CreatedAt.Format(time.RFC3339Nano),
+				user.UpdatedAt.Format(time.RFC3339Nano),
+				lastAccess,
+				lastLogin,
+				fmt.Sprintf("'%s'", strings.Join(paths, "|")),
+			})
+		}
+		w.Flush()
+	} else {
+		users := make([]displayUser, len(userList))
+		for idx, user := range userList {
+			paths := make([]displayLibrary, len(user.Libraries))
+
+			for idx, library := range user.Libraries {
+				paths[idx].ID = library.ID
+				paths[idx].Path = library.Path
+			}
+
+			users[idx].Id = user.ID
+			users[idx].Username = user.UserName
+			users[idx].Name = user.Name
+			users[idx].Email = user.Email
+			users[idx].Admin = user.IsAdmin
+			users[idx].CreatedAt = user.CreatedAt
+			users[idx].UpdatedAt = user.UpdatedAt
+			users[idx].LastAccess = user.LastAccessAt
+			users[idx].LastLogin = user.LastLoginAt
+			users[idx].Libraries = paths
+		}
+
+		j, _ := json.Marshal(users)
+		fmt.Printf("%s\n", j)
+	}
+}

cmd/utils.go

@@ -0,0 +1,42 @@
+package cmd
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/navidrome/navidrome/core/auth"
+	"github.com/navidrome/navidrome/db"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/persistence"
+)
+
+func getAdminContext(ctx context.Context) (model.DataStore, context.Context) {
+	sqlDB := db.Db()
+	ds := persistence.New(sqlDB)
+	ctx = auth.WithAdminUser(ctx, ds)
+	u, _ := request.UserFrom(ctx)
+	if !u.IsAdmin {
+		log.Fatal(ctx, "There must be at least one admin user to run this command.")
+	}
+	return ds, ctx
+}
+
+func getUser(ctx context.Context, id string, ds model.DataStore) (*model.User, error) {
+	user, err := ds.User(ctx).FindByUsername(id)
+
+	if err != nil && !errors.Is(err, model.ErrNotFound) {
+		return nil, fmt.Errorf("finding user by name: %w", err)
+	}
+
+	if errors.Is(err, model.ErrNotFound) {
+		user, err = ds.User(ctx).Get(id)
+		if err != nil {
+			return nil, fmt.Errorf("finding user by id: %w", err)
+		}
+	}
+
+	return user, nil
+}

cmd/wire_gen.go

@@ -9,10 +9,10 @@ package cmd
 import (
 	"context"
 	"github.com/google/wire"
+	"github.com/navidrome/navidrome/adapters/lastfm"
+	"github.com/navidrome/navidrome/adapters/listenbrainz"
 	"github.com/navidrome/navidrome/core"
 	"github.com/navidrome/navidrome/core/agents"
-	"github.com/navidrome/navidrome/core/agents/lastfm"
-	"github.com/navidrome/navidrome/core/agents/listenbrainz"
 	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/core/external"
 	"github.com/navidrome/navidrome/core/ffmpeg"
@@ -22,6 +22,7 @@ import (
 	"github.com/navidrome/navidrome/db"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/persistence"
+	"github.com/navidrome/navidrome/plugins"
 	"github.com/navidrome/navidrome/scanner"
 	"github.com/navidrome/navidrome/server"
 	"github.com/navidrome/navidrome/server/events"
@@ -31,6 +32,11 @@ import (
 )
 
 import (
+	_ "github.com/navidrome/navidrome/adapters/deezer"
+	_ "github.com/navidrome/navidrome/adapters/gotaglib"
+	_ "github.com/navidrome/navidrome/adapters/lastfm"
+	_ "github.com/navidrome/navidrome/adapters/listenbrainz"
+	_ "github.com/navidrome/navidrome/adapters/spotify"
 	_ "github.com/navidrome/navidrome/adapters/taglib"
 )
 
@@ -51,13 +57,27 @@ func CreateServer() *server.Server {
 	return serverServer
 }
 
-func CreateNativeAPIRouter() *nativeapi.Router {
+func CreateNativeAPIRouter(ctx context.Context) *nativeapi.Router {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
 	share := core.NewShare(dataStore)
 	playlists := core.NewPlaylists(dataStore)
 	insights := metrics.GetInstance(dataStore)
-	router := nativeapi.New(dataStore, share, playlists, insights)
+	fileCache := artwork.GetImageCache()
+	fFmpeg := ffmpeg.New()
+	broker := events.GetBroker()
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
+	agentsAgents := agents.GetAgents(dataStore, manager)
+	provider := external.NewProvider(dataStore, agentsAgents)
+	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
+	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
+	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
+	watcher := scanner.GetWatcher(dataStore, modelScanner)
+	library := core.NewLibrary(dataStore, modelScanner, watcher, broker, manager)
+	user := core.NewUser(dataStore, manager)
+	maintenance := core.NewMaintenance(dataStore)
+	router := nativeapi.New(dataStore, share, playlists, insights, library, user, maintenance, manager)
 	return router
 }
 
@@ -66,7 +86,10 @@ func CreateSubsonicAPIRouter(ctx context.Context) *subsonic.Router {
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
 	fFmpeg := ffmpeg.New()
-	agentsAgents := agents.GetAgents(dataStore)
+	broker := events.GetBroker()
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
+	agentsAgents := agents.GetAgents(dataStore, manager)
 	provider := external.NewProvider(dataStore, agentsAgents)
 	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
 	transcodingCache := core.GetTranscodingCache()
@@ -75,13 +98,11 @@ func CreateSubsonicAPIRouter(ctx context.Context) *subsonic.Router {
 	archiver := core.NewArchiver(mediaStreamer, dataStore, share)
 	players := core.NewPlayers(dataStore)
 	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
-	broker := events.GetBroker()
 	playlists := core.NewPlaylists(dataStore)
-	metricsMetrics := metrics.NewPrometheusInstance(dataStore)
-	scannerScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
-	playTracker := scrobbler.GetPlayTracker(dataStore, broker)
+	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
+	playTracker := scrobbler.GetPlayTracker(dataStore, broker, manager)
 	playbackServer := playback.GetInstance(dataStore)
-	router := subsonic.New(dataStore, artworkArtwork, mediaStreamer, archiver, players, provider, scannerScanner, broker, playlists, playTracker, share, playbackServer)
+	router := subsonic.New(dataStore, artworkArtwork, mediaStreamer, archiver, players, provider, modelScanner, broker, playlists, playTracker, share, playbackServer, metricsMetrics)
 	return router
 }
 
@@ -90,7 +111,10 @@ func CreatePublicRouter() *public.Router {
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
 	fFmpeg := ffmpeg.New()
-	agentsAgents := agents.GetAgents(dataStore)
+	broker := events.GetBroker()
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
+	agentsAgents := agents.GetAgents(dataStore, manager)
 	provider := external.NewProvider(dataStore, agentsAgents)
 	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
 	transcodingCache := core.GetTranscodingCache()
@@ -125,24 +149,25 @@ func CreateInsights() metrics.Insights {
 func CreatePrometheus() metrics.Metrics {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
-	metricsMetrics := metrics.NewPrometheusInstance(dataStore)
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
 	return metricsMetrics
 }
 
-func CreateScanner(ctx context.Context) scanner.Scanner {
+func CreateScanner(ctx context.Context) model.Scanner {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
 	fFmpeg := ffmpeg.New()
-	agentsAgents := agents.GetAgents(dataStore)
+	broker := events.GetBroker()
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
+	agentsAgents := agents.GetAgents(dataStore, manager)
 	provider := external.NewProvider(dataStore, agentsAgents)
 	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
 	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
-	broker := events.GetBroker()
 	playlists := core.NewPlaylists(dataStore)
-	metricsMetrics := metrics.NewPrometheusInstance(dataStore)
-	scannerScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
-	return scannerScanner
+	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
+	return modelScanner
 }
 
 func CreateScanWatcher(ctx context.Context) scanner.Watcher {
@@ -150,15 +175,16 @@ func CreateScanWatcher(ctx context.Context) scanner.Watcher {
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
 	fFmpeg := ffmpeg.New()
-	agentsAgents := agents.GetAgents(dataStore)
+	broker := events.GetBroker()
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
+	agentsAgents := agents.GetAgents(dataStore, manager)
 	provider := external.NewProvider(dataStore, agentsAgents)
 	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
 	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
-	broker := events.GetBroker()
 	playlists := core.NewPlaylists(dataStore)
-	metricsMetrics := metrics.NewPrometheusInstance(dataStore)
-	scannerScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
-	watcher := scanner.NewWatcher(dataStore, scannerScanner)
+	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
+	watcher := scanner.GetWatcher(dataStore, modelScanner)
 	return watcher
 }
 
@@ -169,6 +195,21 @@ func GetPlaybackServer() playback.PlaybackServer {
 	return playbackServer
 }
 
+func getPluginManager() *plugins.Manager {
+	sqlDB := db.Db()
+	dataStore := persistence.New(sqlDB)
+	broker := events.GetBroker()
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
+	return manager
+}
+
 // wire_injectors.go:
 
-var allProviders = wire.NewSet(core.Set, artwork.Set, server.New, subsonic.New, nativeapi.New, public.New, persistence.New, lastfm.NewRouter, listenbrainz.NewRouter, events.GetBroker, scanner.New, scanner.NewWatcher, metrics.NewPrometheusInstance, db.Db)
+var allProviders = wire.NewSet(core.Set, artwork.Set, server.New, subsonic.New, nativeapi.New, public.New, persistence.New, lastfm.NewRouter, listenbrainz.NewRouter, events.GetBroker, scanner.New, scanner.GetWatcher, metrics.GetPrometheusInstance, db.Db, plugins.GetManager, wire.Bind(new(agents.PluginLoader), new(*plugins.Manager)), wire.Bind(new(scrobbler.PluginLoader), new(*plugins.Manager)), wire.Bind(new(nativeapi.PluginManager), new(*plugins.Manager)), wire.Bind(new(core.PluginUnloader), new(*plugins.Manager)), wire.Bind(new(plugins.PluginMetricsRecorder), new(metrics.Metrics)), wire.Bind(new(core.Watcher), new(scanner.Watcher)))
+
+func GetPluginManager(ctx context.Context) *plugins.Manager {
+	manager := getPluginManager()
+	manager.SetSubsonicRouter(CreateSubsonicAPIRouter(ctx))
+	return manager
+}

cmd/wire_injectors.go

@@ -6,15 +6,18 @@ import (
 	"context"
 
 	"github.com/google/wire"
+	"github.com/navidrome/navidrome/adapters/lastfm"
+	"github.com/navidrome/navidrome/adapters/listenbrainz"
 	"github.com/navidrome/navidrome/core"
-	"github.com/navidrome/navidrome/core/agents/lastfm"
-	"github.com/navidrome/navidrome/core/agents/listenbrainz"
+	"github.com/navidrome/navidrome/core/agents"
 	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/core/metrics"
 	"github.com/navidrome/navidrome/core/playback"
+	"github.com/navidrome/navidrome/core/scrobbler"
 	"github.com/navidrome/navidrome/db"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/persistence"
+	"github.com/navidrome/navidrome/plugins"
 	"github.com/navidrome/navidrome/scanner"
 	"github.com/navidrome/navidrome/server"
 	"github.com/navidrome/navidrome/server/events"
@@ -35,9 +38,16 @@ var allProviders = wire.NewSet(
 	listenbrainz.NewRouter,
 	events.GetBroker,
 	scanner.New,
-	scanner.NewWatcher,
-	metrics.NewPrometheusInstance,
+	scanner.GetWatcher,
+	metrics.GetPrometheusInstance,
 	db.Db,
+	plugins.GetManager,
+	wire.Bind(new(agents.PluginLoader), new(*plugins.Manager)),
+	wire.Bind(new(scrobbler.PluginLoader), new(*plugins.Manager)),
+	wire.Bind(new(nativeapi.PluginManager), new(*plugins.Manager)),
+	wire.Bind(new(core.PluginUnloader), new(*plugins.Manager)),
+	wire.Bind(new(plugins.PluginMetricsRecorder), new(metrics.Metrics)),
+	wire.Bind(new(core.Watcher), new(scanner.Watcher)),
 )
 
 func CreateDataStore() model.DataStore {
@@ -52,7 +62,7 @@ func CreateServer() *server.Server {
 	))
 }
 
-func CreateNativeAPIRouter() *nativeapi.Router {
+func CreateNativeAPIRouter(ctx context.Context) *nativeapi.Router {
 	panic(wire.Build(
 		allProviders,
 	))
@@ -94,7 +104,7 @@ func CreatePrometheus() metrics.Metrics {
 	))
 }
 
-func CreateScanner(ctx context.Context) scanner.Scanner {
+func CreateScanner(ctx context.Context) model.Scanner {
 	panic(wire.Build(
 		allProviders,
 	))
@@ -111,3 +121,15 @@ func GetPlaybackServer() playback.PlaybackServer {
 		allProviders,
 	))
 }
+
+func getPluginManager() *plugins.Manager {
+	panic(wire.Build(
+		allProviders,
+	))
+}
+
+func GetPluginManager(ctx context.Context) *plugins.Manager {
+	manager := getPluginManager()
+	manager.SetSubsonicRouter(CreateSubsonicAPIRouter(ctx))
+	return manager
+}

conf/configuration.go

@@ -1,6 +1,7 @@
 package conf
 
 import (
+	"cmp"
 	"fmt"
 	"net/url"
 	"os"
@@ -14,7 +15,7 @@ import (
 	"github.com/kr/pretty"
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/log"
-	"github.com/navidrome/navidrome/utils/chain"
+	"github.com/navidrome/navidrome/utils/run"
 	"github.com/robfig/cron/v3"
 	"github.com/spf13/viper"
 )
@@ -41,6 +42,7 @@ type configOptions struct {
 	UIWelcomeMessage                string
 	MaxSidebarPlaylists             int
 	EnableTranscodingConfig         bool
+	EnableTranscodingCancellation   bool
 	EnableDownloads                 bool
 	EnableExternalServices          bool
 	EnableInsightsCollector         bool
@@ -56,6 +58,7 @@ type configOptions struct {
 	AutoTranscodeDownload           bool
 	DefaultDownsamplingFormat       string
 	SearchFullString                bool
+	SimilarSongsMatchThreshold      int
 	RecentlyAddedByModTime          bool
 	PreferSortTags                  bool
 	IgnoredArticles                 string
@@ -66,6 +69,7 @@ type configOptions struct {
 	CoverArtPriority                string
 	CoverJpegQuality                int
 	ArtistArtPriority               string
+	LyricsPriority                  string
 	EnableGravatar                  bool
 	EnableFavourites                bool
 	EnableStarRating                bool
@@ -79,49 +83,59 @@ type configOptions struct {
 	DefaultUIVolume                 int
 	EnableReplayGain                bool
 	EnableCoverAnimation            bool
+	EnableNowPlaying                bool
 	GATrackingID                    string
 	EnableLogRedacting              bool
 	AuthRequestLimit                int
 	AuthWindowLength                time.Duration
 	PasswordEncryptionKey           string
-	ReverseProxyUserHeader          string
-	ReverseProxyWhitelist           string
-	HTTPSecurityHeaders             secureOptions
-	Prometheus                      prometheusOptions
-	Scanner                         scannerOptions
-	Jukebox                         jukeboxOptions
-	Backup                          backupOptions
-	PID                             pidOptions
-	Inspect                         inspectOptions
-	Subsonic                        subsonicOptions
-	LyricsPriority                  string
-
-	Agents       string
-	LastFM       lastfmOptions
-	Spotify      spotifyOptions
-	ListenBrainz listenBrainzOptions
-	Tags         map[string]TagConf
+	ExtAuth                         extAuthOptions
+	Plugins                         pluginsOptions
+	HTTPHeaders                     httpHeaderOptions   `json:",omitzero"`
+	Prometheus                      prometheusOptions   `json:",omitzero"`
+	Scanner                         scannerOptions      `json:",omitzero"`
+	Jukebox                         jukeboxOptions      `json:",omitzero"`
+	Backup                          backupOptions       `json:",omitzero"`
+	PID                             pidOptions          `json:",omitzero"`
+	Inspect                         inspectOptions      `json:",omitzero"`
+	Subsonic                        subsonicOptions     `json:",omitzero"`
+	LastFM                          lastfmOptions       `json:",omitzero"`
+	Spotify                         spotifyOptions      `json:",omitzero"`
+	Deezer                          deezerOptions       `json:",omitzero"`
+	ListenBrainz                    listenBrainzOptions `json:",omitzero"`
+	EnableScrobbleHistory           bool
+	Tags                            map[string]TagConf `json:",omitempty"`
+	Agents                          string
 
 	// DevFlags. These are used to enable/disable debugging and incomplete features
-	DevLogSourceLine                 bool
-	DevLogLevels                     map[string]string
-	DevEnableProfiler                bool
-	DevAutoCreateAdminPassword       string
-	DevAutoLoginUsername             string
-	DevActivityPanel                 bool
-	DevActivityPanelUpdateRate       time.Duration
-	DevSidebarPlaylists              bool
-	DevShowArtistPage                bool
-	DevOffsetOptimize                int
-	DevArtworkMaxRequests            int
-	DevArtworkThrottleBacklogLimit   int
-	DevArtworkThrottleBacklogTimeout time.Duration
-	DevArtistInfoTimeToLive          time.Duration
-	DevAlbumInfoTimeToLive           time.Duration
-	DevExternalScanner               bool
-	DevScannerThreads                uint
-	DevInsightsInitialDelay          time.Duration
-	DevEnablePlayerInsights          bool
+	DevLogLevels                      map[string]string `json:",omitempty"`
+	DevLogSourceLine                  bool
+	DevEnableProfiler                 bool
+	DevAutoCreateAdminPassword        string
+	DevAutoLoginUsername              string
+	DevActivityPanel                  bool
+	DevActivityPanelUpdateRate        time.Duration
+	DevSidebarPlaylists               bool
+	DevShowArtistPage                 bool
+	DevUIShowConfig                   bool
+	DevNewEventStream                 bool
+	DevOffsetOptimize                 int
+	DevArtworkMaxRequests             int
+	DevArtworkThrottleBacklogLimit    int
+	DevArtworkThrottleBacklogTimeout  time.Duration
+	DevArtistInfoTimeToLive           time.Duration
+	DevAlbumInfoTimeToLive            time.Duration
+	DevExternalScanner                bool
+	DevScannerThreads                 uint
+	DevSelectiveWatcher               bool
+	DevLegacyEmbedImage               bool
+	DevInsightsInitialDelay           time.Duration
+	DevEnablePlayerInsights           bool
+	DevEnablePluginsInsights          bool
+	DevPluginCompilationTimeout       time.Duration
+	DevExternalArtistFetchMultiplier  float64
+	DevOptimizeDB                     bool
+	DevPreserveUnicodeInExternalCalls bool
 }
 
 type scannerOptions struct {
@@ -141,16 +155,18 @@ type subsonicOptions struct {
 	AppendSubtitle        bool
 	ArtistParticipations  bool
 	DefaultReportRealPath bool
+	EnableAverageRating   bool
 	LegacyClients         string
+	MinimalClients        string
 }
 
 type TagConf struct {
-	Ignore    bool     `yaml:"ignore"`
-	Aliases   []string `yaml:"aliases"`
-	Type      string   `yaml:"type"`
-	MaxLength int      `yaml:"maxLength"`
-	Split     []string `yaml:"split"`
-	Album     bool     `yaml:"album"`
+	Ignore    bool     `yaml:"ignore" json:",omitempty"`
+	Aliases   []string `yaml:"aliases" json:",omitempty"`
+	Type      string   `yaml:"type" json:",omitempty"`
+	MaxLength int      `yaml:"maxLength" json:",omitempty"`
+	Split     []string `yaml:"split" json:",omitempty"`
+	Album     bool     `yaml:"album" json:",omitempty"`
 }
 
 type lastfmOptions struct {
@@ -159,6 +175,9 @@ type lastfmOptions struct {
 	Secret                  string
 	Language                string
 	ScrobbleFirstArtistOnly bool
+
+	// Computed values
+	Languages []string // Computed from Language, split by comma
 }
 
 type spotifyOptions struct {
@@ -166,13 +185,21 @@ type spotifyOptions struct {
 	Secret string
 }
 
+type deezerOptions struct {
+	Enabled  bool
+	Language string
+
+	// Computed values
+	Languages []string // Computed from Language, split by comma
+}
+
 type listenBrainzOptions struct {
 	Enabled bool
 	BaseURL string
 }
 
-type secureOptions struct {
-	CustomFrameOptionsValue string
+type httpHeaderOptions struct {
+	FrameOptions string
 }
 
 type prometheusOptions struct {
@@ -208,6 +235,19 @@ type inspectOptions struct {
 	BacklogTimeout int
 }
 
+type pluginsOptions struct {
+	Enabled    bool
+	Folder     string
+	CacheSize  string
+	AutoReload bool
+	LogLevel   string
+}
+
+type extAuthOptions struct {
+	TrustedSources string
+	UserHeader     string
+}
+
 var (
 	Server = &configOptions{}
 	hooks  []func()
@@ -226,6 +266,11 @@ func LoadFromFile(confFile string) {
 func Load(noConfigDump bool) {
 	parseIniFileConfiguration()
 
+	// Map deprecated options to their new names for backwards compatibility
+	mapDeprecatedOption("ReverseProxyWhitelist", "ExtAuth.TrustedSources")
+	mapDeprecatedOption("ReverseProxyUserHeader", "ExtAuth.UserHeader")
+	mapDeprecatedOption("HTTPSecurityHeaders.CustomFrameOptionsValue", "HTTPHeaders.FrameOptions")
+
 	err := viper.Unmarshal(&Server)
 	if err != nil {
 		_, _ = fmt.Fprintln(os.Stderr, "FATAL: Error parsing config:", err)
@@ -247,6 +292,17 @@ func Load(noConfigDump bool) {
 		os.Exit(1)
 	}
 
+	if Server.Plugins.Enabled {
+		if Server.Plugins.Folder == "" {
+			Server.Plugins.Folder = filepath.Join(Server.DataFolder, "plugins")
+		}
+		err = os.MkdirAll(Server.Plugins.Folder, 0700)
+		if err != nil {
+			_, _ = fmt.Fprintln(os.Stderr, "FATAL: Error creating plugins path:", err)
+			os.Exit(1)
+		}
+	}
+
 	Server.ConfigFile = viper.GetViper().ConfigFileUsed()
 	if Server.DbPath == "" {
 		Server.DbPath = filepath.Join(Server.DataFolder, consts.DefaultDbPath)
@@ -275,7 +331,7 @@ func Load(noConfigDump bool) {
 	log.SetLogSourceLine(Server.DevLogSourceLine)
 	log.SetRedacting(Server.EnableLogRedacting)
 
-	err = chain.RunSequentially(
+	err = run.Sequentially(
 		validateScanSchedule,
 		validateBackupSchedule,
 		validatePlaylistsPath,
@@ -298,9 +354,18 @@ func Load(noConfigDump bool) {
 		Server.BaseScheme = u.Scheme
 	}
 
+	// Log configuration source
+	if Server.ConfigFile != "" {
+		log.Info("Loaded configuration", "file", Server.ConfigFile)
+	} else if hasNDEnvVars() {
+		log.Info("No configuration file found. Loaded configuration only from environment variables")
+	} else {
+		log.Warn("No configuration file found. Using default values. To specify a config file, use the --configfile flag or set the ND_CONFIGFILE environment variable.")
+	}
+
 	// Print current configuration if log level is Debug
 	if log.IsGreaterOrEqualTo(log.LevelDebug) && !noConfigDump {
-		prettyConf := pretty.Sprintf("Loaded configuration from '%s': %# v", Server.ConfigFile, Server)
+		prettyConf := pretty.Sprintf("Configuration: %# v", Server)
 		if Server.EnableLogRedacting {
 			prettyConf = log.Redact(prettyConf)
 		}
@@ -311,13 +376,22 @@ func Load(noConfigDump bool) {
 		disableExternalServices()
 	}
 
-	if Server.Scanner.Extractor != consts.DefaultScannerExtractor {
-		log.Warn(fmt.Sprintf("Extractor '%s' is not implemented, using 'taglib'", Server.Scanner.Extractor))
-		Server.Scanner.Extractor = consts.DefaultScannerExtractor
-	}
-	logDeprecatedOptions("Scanner.GenreSeparators")
-	logDeprecatedOptions("Scanner.GroupAlbumReleases")
-	logDeprecatedOptions("DevEnableBufferedScrobble") // Deprecated: Buffered scrobbling is now always enabled and this option is ignored
+	// Make sure we don't have empty PIDs
+	Server.PID.Album = cmp.Or(Server.PID.Album, consts.DefaultAlbumPID)
+	Server.PID.Track = cmp.Or(Server.PID.Track, consts.DefaultTrackPID)
+
+	// Parse LastFM.Language into Languages slice (comma-separated, with fallback to DefaultInfoLanguage)
+	Server.LastFM.Languages = parseLanguages(Server.LastFM.Language)
+
+	// Parse Deezer.Language into Languages slice (comma-separated, with fallback to DefaultInfoLanguage)
+	Server.Deezer.Languages = parseLanguages(Server.Deezer.Language)
+
+	logDeprecatedOptions("Scanner.GenreSeparators", "")
+	logDeprecatedOptions("Scanner.GroupAlbumReleases", "")
+	logDeprecatedOptions("DevEnableBufferedScrobble", "") // Deprecated: Buffered scrobbling is now always enabled and this option is ignored
+	logDeprecatedOptions("ReverseProxyWhitelist", "ExtAuth.TrustedSources")
+	logDeprecatedOptions("ReverseProxyUserHeader", "ExtAuth.UserHeader")
+	logDeprecatedOptions("HTTPSecurityHeaders.CustomFrameOptionsValue", "HTTPHeaders.FrameOptions")
 
 	// Call init hooks
 	for _, hook := range hooks {
@@ -325,16 +399,30 @@ func Load(noConfigDump bool) {
 	}
 }
 
-func logDeprecatedOptions(options ...string) {
-	for _, option := range options {
-		envVar := "ND_" + strings.ToUpper(strings.ReplaceAll(option, ".", "_"))
-		if os.Getenv(envVar) != "" {
-			log.Warn(fmt.Sprintf("Option '%s' is deprecated and will be ignored in a future release", envVar))
-		}
-		if viper.InConfig(option) {
-			log.Warn(fmt.Sprintf("Option '%s' is deprecated and will be ignored in a future release", option))
+func logDeprecatedOptions(oldName, newName string) {
+	envVar := "ND_" + strings.ToUpper(strings.ReplaceAll(oldName, ".", "_"))
+	newEnvVar := "ND_" + strings.ToUpper(strings.ReplaceAll(newName, ".", "_"))
+	logWarning := func(oldName, newName string) {
+		if newName != "" {
+			log.Warn(fmt.Sprintf("Option '%s' is deprecated and will be ignored in a future release. Please use the new '%s'", oldName, newName))
+		} else {
+			log.Warn(fmt.Sprintf("Option '%s' is deprecated and will be ignored in a future release", oldName))
 		}
 	}
+	if os.Getenv(envVar) != "" {
+		logWarning(envVar, newEnvVar)
+	}
+	if viper.InConfig(oldName) {
+		logWarning(oldName, newName)
+	}
+}
+
+// mapDeprecatedOption is used to provide backwards compatibility for deprecated options. It should be called after
+// the config has been read by viper, but before unmarshalling it into the Config struct.
+func mapDeprecatedOption(legacyName, newName string) {
+	if viper.IsSet(legacyName) {
+		viper.Set(newName, viper.Get(legacyName))
+	}
 }
 
 // parseIniFileConfiguration is used to parse the config file when it is in INI format. For INI files, it
@@ -367,6 +455,7 @@ func disableExternalServices() {
 	Server.EnableInsightsCollector = false
 	Server.LastFM.Enabled = false
 	Server.Spotify.ID = ""
+	Server.Deezer.Enabled = false
 	Server.ListenBrainz.Enabled = false
 	Server.Agents = ""
 	if Server.UILoginBackgroundURL == consts.DefaultUILoginBackgroundURL {
@@ -385,6 +474,22 @@ func validatePlaylistsPath() error {
 	return nil
 }
 
+// parseLanguages parses a comma-separated language string into a slice.
+// It trims whitespace from each entry and ensures at least [DefaultInfoLanguage] is returned.
+func parseLanguages(lang string) []string {
+	var languages []string
+	for _, l := range strings.Split(lang, ",") {
+		l = strings.TrimSpace(l)
+		if l != "" {
+			languages = append(languages, l)
+		}
+	}
+	if len(languages) == 0 {
+		return []string{consts.DefaultInfoLanguage}
+	}
+	return languages
+}
+
 func validatePurgeMissingOption() error {
 	allowedValues := []string{consts.PurgeMissingNever, consts.PurgeMissingAlways, consts.PurgeMissingFull}
 	valid := false
@@ -395,7 +500,7 @@ func validatePurgeMissingOption() error {
 		}
 	}
 	if !valid {
-		err := fmt.Errorf("Invalid Scanner.PurgeMissing value: '%s'. Must be one of: %v", Server.Scanner.PurgeMissing, allowedValues)
+		err := fmt.Errorf("invalid Scanner.PurgeMissing value: '%s'. Must be one of: %v", Server.Scanner.PurgeMissing, allowedValues)
 		log.Error(err.Error())
 		Server.Scanner.PurgeMissing = consts.PurgeMissingNever
 		return err
@@ -442,6 +547,16 @@ func AddHook(hook func()) {
 	hooks = append(hooks, hook)
 }
 
+// hasNDEnvVars checks if any ND_ prefixed environment variables are set (excluding ND_CONFIGFILE)
+func hasNDEnvVars() bool {
+	for _, env := range os.Environ() {
+		if strings.HasPrefix(env, "ND_") && !strings.HasPrefix(env, "ND_CONFIGFILE=") {
+			return true
+		}
+	}
+	return false
+}
+
 func setViperDefaults() {
 	viper.SetDefault("musicfolder", filepath.Join(".", "music"))
 	viper.SetDefault("cachefolder", "")
@@ -459,6 +574,7 @@ func setViperDefaults() {
 	viper.SetDefault("uiwelcomemessage", "")
 	viper.SetDefault("maxsidebarplaylists", consts.DefaultMaxSidebarPlaylists)
 	viper.SetDefault("enabletranscodingconfig", false)
+	viper.SetDefault("enabletranscodingcancellation", false)
 	viper.SetDefault("transcodingcachesize", "100MB")
 	viper.SetDefault("imagecachesize", "100MB")
 	viper.SetDefault("albumplaycountmode", consts.AlbumPlayCountModeAbsolute)
@@ -473,15 +589,17 @@ func setViperDefaults() {
 	viper.SetDefault("autotranscodedownload", false)
 	viper.SetDefault("defaultdownsamplingformat", consts.DefaultDownsamplingFormat)
 	viper.SetDefault("searchfullstring", false)
+	viper.SetDefault("similarsongsmatchthreshold", 85)
 	viper.SetDefault("recentlyaddedbymodtime", false)
 	viper.SetDefault("prefersorttags", false)
 	viper.SetDefault("ignoredarticles", "The El La Los Las Le Les Os As O A")
 	viper.SetDefault("indexgroups", "A B C D E F G H I J K L M N O P Q R S T U V W X-Z(XYZ) [Unknown]([)")
 	viper.SetDefault("ffmpegpath", "")
-	viper.SetDefault("mpvcmdtemplate", "mpv --audio-device=%d --no-audio-display --pause %f --input-ipc-server=%s")
+	viper.SetDefault("mpvcmdtemplate", "mpv --audio-device=%d --no-audio-display %f --input-ipc-server=%s")
 	viper.SetDefault("coverartpriority", "cover.*, folder.*, front.*, embedded, external")
 	viper.SetDefault("coverjpegquality", 75)
 	viper.SetDefault("artistartpriority", "artist.*, album/artist.*, external")
+	viper.SetDefault("lyricspriority", ".lrc,.txt,embedded")
 	viper.SetDefault("enablegravatar", false)
 	viper.SetDefault("enablefavourites", true)
 	viper.SetDefault("enablestarrating", true)
@@ -491,6 +609,7 @@ func setViperDefaults() {
 	viper.SetDefault("defaultuivolume", consts.DefaultUIVolume)
 	viper.SetDefault("enablereplaygain", true)
 	viper.SetDefault("enablecoveranimation", true)
+	viper.SetDefault("enablenowplaying", true)
 	viper.SetDefault("enablesharing", false)
 	viper.SetDefault("shareurl", "")
 	viper.SetDefault("defaultshareexpiration", 8760*time.Hour)
@@ -501,8 +620,8 @@ func setViperDefaults() {
 	viper.SetDefault("authrequestlimit", 5)
 	viper.SetDefault("authwindowlength", 20*time.Second)
 	viper.SetDefault("passwordencryptionkey", "")
-	viper.SetDefault("reverseproxyuserheader", "Remote-User")
-	viper.SetDefault("reverseproxywhitelist", "")
+	viper.SetDefault("extauth.userheader", "Remote-User")
+	viper.SetDefault("extauth.trustedsources", "")
 	viper.SetDefault("prometheus.enabled", false)
 	viper.SetDefault("prometheus.metricspath", consts.PrometheusDefaultPath)
 	viper.SetDefault("prometheus.password", "")
@@ -519,22 +638,27 @@ func setViperDefaults() {
 	viper.SetDefault("scanner.genreseparators", "")
 	viper.SetDefault("scanner.groupalbumreleases", false)
 	viper.SetDefault("scanner.followsymlinks", true)
-	viper.SetDefault("scanner.purgemissing", "never")
+	viper.SetDefault("scanner.purgemissing", consts.PurgeMissingNever)
 	viper.SetDefault("subsonic.appendsubtitle", true)
 	viper.SetDefault("subsonic.artistparticipations", false)
 	viper.SetDefault("subsonic.defaultreportrealpath", false)
+	viper.SetDefault("subsonic.enableaveragerating", true)
 	viper.SetDefault("subsonic.legacyclients", "DSub")
-	viper.SetDefault("agents", "lastfm,spotify")
+	viper.SetDefault("subsonic.minimalclients", "SubMusic")
+	viper.SetDefault("agents", "lastfm,spotify,deezer")
 	viper.SetDefault("lastfm.enabled", true)
-	viper.SetDefault("lastfm.language", "en")
+	viper.SetDefault("lastfm.language", consts.DefaultInfoLanguage)
 	viper.SetDefault("lastfm.apikey", "")
 	viper.SetDefault("lastfm.secret", "")
 	viper.SetDefault("lastfm.scrobblefirstartistonly", false)
 	viper.SetDefault("spotify.id", "")
 	viper.SetDefault("spotify.secret", "")
+	viper.SetDefault("deezer.enabled", true)
+	viper.SetDefault("deezer.language", consts.DefaultInfoLanguage)
 	viper.SetDefault("listenbrainz.enabled", true)
 	viper.SetDefault("listenbrainz.baseurl", "https://api.listenbrainz.org/1/")
-	viper.SetDefault("httpsecurityheaders.customframeoptionsvalue", "DENY")
+	viper.SetDefault("enablescrobblehistory", true)
+	viper.SetDefault("httpheaders.frameoptions", "DENY")
 	viper.SetDefault("backup.path", "")
 	viper.SetDefault("backup.schedule", "")
 	viper.SetDefault("backup.count", 0)
@@ -544,7 +668,12 @@ func setViperDefaults() {
 	viper.SetDefault("inspect.maxrequests", 1)
 	viper.SetDefault("inspect.backloglimit", consts.RequestThrottleBacklogLimit)
 	viper.SetDefault("inspect.backlogtimeout", consts.RequestThrottleBacklogTimeout)
-	viper.SetDefault("lyricspriority", ".lrc,.txt,embedded")
+	viper.SetDefault("plugins.folder", "")
+	viper.SetDefault("plugins.enabled", true)
+	viper.SetDefault("plugins.cachesize", "200MB")
+	viper.SetDefault("plugins.autoreload", false)
+
+	// DevFlags. These are used to enable/disable debugging and incomplete features
 	viper.SetDefault("devlogsourceline", false)
 	viper.SetDefault("devenableprofiler", false)
 	viper.SetDefault("devautocreateadminpassword", "")
@@ -553,6 +682,8 @@ func setViperDefaults() {
 	viper.SetDefault("devactivitypanelupdaterate", 300*time.Millisecond)
 	viper.SetDefault("devsidebarplaylists", true)
 	viper.SetDefault("devshowartistpage", true)
+	viper.SetDefault("devuishowconfig", true)
+	viper.SetDefault("devneweventstream", true)
 	viper.SetDefault("devoffsetoptimize", 50000)
 	viper.SetDefault("devartworkmaxrequests", max(2, runtime.NumCPU()/3))
 	viper.SetDefault("devartworkthrottlebackloglimit", consts.RequestThrottleBacklogLimit)
@@ -561,17 +692,28 @@ func setViperDefaults() {
 	viper.SetDefault("devalbuminfotimetolive", consts.AlbumInfoTimeToLive)
 	viper.SetDefault("devexternalscanner", true)
 	viper.SetDefault("devscannerthreads", 5)
+	viper.SetDefault("devselectivewatcher", true)
 	viper.SetDefault("devinsightsinitialdelay", consts.InsightsInitialDelay)
 	viper.SetDefault("devenableplayerinsights", true)
+	viper.SetDefault("devenablepluginsinsights", true)
+	viper.SetDefault("devplugincompilationtimeout", time.Minute)
+	viper.SetDefault("devexternalartistfetchmultiplier", 1.5)
+	viper.SetDefault("devoptimizedb", true)
+	viper.SetDefault("devpreserveunicodeinexternalcalls", false)
 }
 
 func init() {
 	setViperDefaults()
 }
 
-func InitConfig(cfgFile string) {
+func InitConfig(cfgFile string, loadEnvVars bool) {
 	codecRegistry := viper.NewCodecRegistry()
-	_ = codecRegistry.RegisterCodec("ini", ini.Codec{})
+	_ = codecRegistry.RegisterCodec("ini", ini.Codec{
+		LoadOptions: ini.LoadOptions{
+			UnescapeValueDoubleQuotes:   true,
+			UnescapeValueCommentSymbols: true,
+		},
+	})
 	viper.SetOptions(viper.WithCodecRegistry(codecRegistry))
 
 	cfgFile = getConfigFile(cfgFile)
@@ -585,10 +727,12 @@ func InitConfig(cfgFile string) {
 	}
 
 	_ = viper.BindEnv("port")
-	viper.SetEnvPrefix("ND")
-	replacer := strings.NewReplacer(".", "_")
-	viper.SetEnvKeyReplacer(replacer)
-	viper.AutomaticEnv()
+	if loadEnvVars {
+		viper.SetEnvPrefix("ND")
+		replacer := strings.NewReplacer(".", "_")
+		viper.SetEnvKeyReplacer(replacer)
+		viper.AutomaticEnv()
+	}
 
 	err := viper.ReadInConfig()
 	if viper.ConfigFileUsed() != "" && err != nil {

conf/configuration_test.go

@@ -26,12 +26,38 @@ var _ = Describe("Configuration", func() {
 		conf.ResetConf()
 	})
 
+	Describe("ParseLanguages", func() {
+		It("parses single language", func() {
+			Expect(conf.ParseLanguages("en")).To(Equal([]string{"en"}))
+		})
+
+		It("parses multiple comma-separated languages", func() {
+			Expect(conf.ParseLanguages("pt,en")).To(Equal([]string{"pt", "en"}))
+		})
+
+		It("trims whitespace from languages", func() {
+			Expect(conf.ParseLanguages(" pt , en ")).To(Equal([]string{"pt", "en"}))
+		})
+
+		It("returns default 'en' when empty", func() {
+			Expect(conf.ParseLanguages("")).To(Equal([]string{"en"}))
+		})
+
+		It("returns default 'en' when only whitespace", func() {
+			Expect(conf.ParseLanguages("   ")).To(Equal([]string{"en"}))
+		})
+
+		It("handles multiple languages with various spacing", func() {
+			Expect(conf.ParseLanguages("ja, pt, en")).To(Equal([]string{"ja", "pt", "en"}))
+		})
+	})
+
 	DescribeTable("should load configuration from",
 		func(format string) {
 			filename := filepath.Join("testdata", "cfg."+format)
 
 			// Initialize config with the test file
-			conf.InitConfig(filename)
+			conf.InitConfig(filename, false)
 			// Load the configuration (with noConfigDump=true)
 			conf.Load(true)
 
@@ -39,6 +65,10 @@ var _ = Describe("Configuration", func() {
 			Expect(conf.Server.MusicFolder).To(Equal(fmt.Sprintf("/%s/music", format)))
 			Expect(conf.Server.UIWelcomeMessage).To(Equal("Welcome " + format))
 			Expect(conf.Server.Tags["custom"].Aliases).To(Equal([]string{format, "test"}))
+			Expect(conf.Server.Tags["artist"].Split).To(Equal([]string{";"}))
+
+			// Check deprecated option mapping
+			Expect(conf.Server.ExtAuth.UserHeader).To(Equal("X-Auth-User"))
 
 			// The config file used should be the one we created
 			Expect(conf.Server.ConfigFile).To(Equal(filename))

conf/export_test.go

@@ -5,3 +5,5 @@ func ResetConf() {
 }
 
 var SetViperDefaults = setViperDefaults
+
+var ParseLanguages = parseLanguages

conf/testdata/cfg.ini

@@ -1,6 +1,8 @@
 [default]
 MusicFolder = /ini/music
-UIWelcomeMessage = Welcome ini
+UIWelcomeMessage = 'Welcome ini' ; Just a comment to test the LoadOptions
+ReverseProxyUserHeader = 'X-Auth-User'
 
 [Tags]
-Custom.Aliases = ini,test
+Custom.Aliases = ini,test
+artist.Split = ";" # Should be able to read ; as a separator

conf/testdata/cfg.json

@@ -1,7 +1,11 @@
 {
   "musicFolder": "/json/music",
   "uiWelcomeMessage": "Welcome json",
+  "reverseProxyUserHeader": "X-Auth-User",
   "Tags": {
+    "artist": {
+      "split": ";"
+    },
     "custom": {
       "aliases": [
         "json",

conf/testdata/cfg.toml

@@ -1,5 +1,8 @@
 musicFolder = "/toml/music"
 uiWelcomeMessage = "Welcome toml"
+ReverseProxyUserHeader = "X-Auth-User"
+
+Tags.artist.Split = ';'
 
 [Tags.custom]
 aliases = ["toml", "test"]

conf/testdata/cfg.yaml

@@ -1,6 +1,9 @@
 musicFolder: "/yaml/music"
 uiWelcomeMessage: "Welcome yaml"
+reverseProxyUserHeader: "X-Auth-User"
 Tags:
+  artist:
+    split:  [";"]
   custom:
     aliases:
       - yaml

consts/consts.go

@@ -56,6 +56,8 @@ const (
 
 	ServerReadHeaderTimeout = 3 * time.Second
 
+	DefaultInfoLanguage = "en"
+
 	ArtistInfoTimeToLive      = 24 * time.Hour
 	AlbumInfoTimeToLive       = 7 * 24 * time.Hour
 	UpdateLastAccessFrequency = time.Minute
@@ -150,6 +152,8 @@ var (
 	}
 )
 
+var HTTPUserAgent = "Navidrome" + "/" + Version
+
 var (
 	VariousArtists = "Various Artists"
 	// TODO This will be dynamic when using disambiguation

core/agents/agents.go

@@ -2,6 +2,7 @@ package agents
 
 import (
 	"context"
+	"slices"
 	"strings"
 	"time"
 
@@ -13,43 +14,110 @@ import (
 	"github.com/navidrome/navidrome/utils/singleton"
 )
 
-type Agents struct {
-	ds     model.DataStore
-	agents []Interface
+// PluginLoader defines an interface for loading plugins
+type PluginLoader interface {
+	// PluginNames returns the names of all plugins that implement a particular service
+	PluginNames(capability string) []string
+	// LoadMediaAgent loads and returns a media agent plugin
+	LoadMediaAgent(name string) (Interface, bool)
 }
 
-func GetAgents(ds model.DataStore) *Agents {
+// Agents is a meta-agent that aggregates multiple built-in and plugin agents. It tries each enabled agent in order
+// until one returns valid data.
+type Agents struct {
+	ds           model.DataStore
+	pluginLoader PluginLoader
+}
+
+// GetAgents returns the singleton instance of Agents
+func GetAgents(ds model.DataStore, pluginLoader PluginLoader) *Agents {
 	return singleton.GetInstance(func() *Agents {
-		return createAgents(ds)
+		return createAgents(ds, pluginLoader)
 	})
 }
 
-func createAgents(ds model.DataStore) *Agents {
-	var order []string
-	if conf.Server.Agents != "" {
-		order = strings.Split(conf.Server.Agents, ",")
+// createAgents creates a new Agents instance. Used in tests
+func createAgents(ds model.DataStore, pluginLoader PluginLoader) *Agents {
+	return &Agents{
+		ds:           ds,
+		pluginLoader: pluginLoader,
 	}
-	order = append(order, LocalAgentName)
-	var res []Interface
-	var enabled []string
-	for _, name := range order {
-		init, ok := Map[name]
-		if !ok {
-			log.Error("Invalid agent. Check `Agents` configuration", "name", name, "conf", conf.Server.Agents)
-			continue
-		}
+}
 
-		agent := init(ds)
-		if agent == nil {
-			log.Debug("Agent not available. Missing configuration?", "name", name)
-			continue
-		}
-		enabled = append(enabled, name)
-		res = append(res, init(ds))
+// enabledAgent represents an enabled agent with its type information
+type enabledAgent struct {
+	name     string
+	isPlugin bool
+}
+
+// getEnabledAgentNames returns the current list of enabled agents, including:
+// 1. Built-in agents and plugins from config (in the specified order)
+// 2. Always include LocalAgentName
+// 3. If config is empty, include ONLY LocalAgentName
+// Each enabledAgent contains the name and whether it's a plugin (true) or built-in (false)
+func (a *Agents) getEnabledAgentNames() []enabledAgent {
+	// If no agents configured, ONLY use the local agent
+	if conf.Server.Agents == "" {
+		return []enabledAgent{{name: LocalAgentName, isPlugin: false}}
 	}
-	log.Debug("List of agents enabled", "names", enabled)
 
-	return &Agents{ds: ds, agents: res}
+	// Get all available plugin names
+	var availablePlugins []string
+	if a.pluginLoader != nil {
+		availablePlugins = a.pluginLoader.PluginNames("MetadataAgent")
+	}
+	log.Trace("Available MetadataAgent plugins", "plugins", availablePlugins)
+
+	configuredAgents := strings.Split(conf.Server.Agents, ",")
+
+	// Always add LocalAgentName if not already included
+	hasLocalAgent := slices.Contains(configuredAgents, LocalAgentName)
+	if !hasLocalAgent {
+		configuredAgents = append(configuredAgents, LocalAgentName)
+	}
+
+	// Filter to only include valid agents (built-in or plugins)
+	var validAgents []enabledAgent
+	for _, name := range configuredAgents {
+		// Check if it's a built-in agent
+		isBuiltIn := Map[name] != nil
+
+		// Check if it's a plugin
+		isPlugin := slices.Contains(availablePlugins, name)
+
+		if isBuiltIn {
+			validAgents = append(validAgents, enabledAgent{name: name, isPlugin: false})
+		} else if isPlugin {
+			validAgents = append(validAgents, enabledAgent{name: name, isPlugin: true})
+		} else {
+			log.Debug("Unknown agent ignored", "name", name)
+		}
+	}
+	return validAgents
+}
+
+func (a *Agents) getAgent(ea enabledAgent) Interface {
+	if ea.isPlugin {
+		// Try to load WASM plugin agent (if plugin loader is available)
+		if a.pluginLoader != nil {
+			agent, ok := a.pluginLoader.LoadMediaAgent(ea.name)
+			if ok && agent != nil {
+				return agent
+			}
+		}
+	} else {
+		// Try to get built-in agent
+		constructor, ok := Map[ea.name]
+		if ok {
+			agent := constructor(a.ds)
+			if agent != nil {
+				return agent
+			}
+			log.Debug("Built-in agent not available. Missing configuration?", "name", ea.name)
+		}
+	}
+
+	return nil
 }
 
 func (a *Agents) AgentName() string {
@@ -63,22 +131,14 @@ func (a *Agents) GetArtistMBID(ctx context.Context, id string, name string) (str
 	case consts.VariousArtistsID:
 		return "", nil
 	}
-	start := time.Now()
-	for _, ag := range a.agents {
-		if utils.IsCtxDone(ctx) {
-			break
-		}
-		agent, ok := ag.(ArtistMBIDRetriever)
+
+	return callAgentMethod(ctx, a, "GetArtistMBID", func(ag Interface) (string, error) {
+		retriever, ok := ag.(ArtistMBIDRetriever)
 		if !ok {
-			continue
+			return "", ErrNotFound
 		}
-		mbid, err := agent.GetArtistMBID(ctx, id, name)
-		if mbid != "" && err == nil {
-			log.Debug(ctx, "Got MBID", "agent", ag.AgentName(), "artist", name, "mbid", mbid, "elapsed", time.Since(start))
-			return mbid, nil
-		}
-	}
-	return "", ErrNotFound
+		return retriever.GetArtistMBID(ctx, id, name)
+	})
 }
 
 func (a *Agents) GetArtistURL(ctx context.Context, id, name, mbid string) (string, error) {
@@ -88,22 +148,14 @@ func (a *Agents) GetArtistURL(ctx context.Context, id, name, mbid string) (strin
 	case consts.VariousArtistsID:
 		return "", nil
 	}
-	start := time.Now()
-	for _, ag := range a.agents {
-		if utils.IsCtxDone(ctx) {
-			break
-		}
-		agent, ok := ag.(ArtistURLRetriever)
+
+	return callAgentMethod(ctx, a, "GetArtistURL", func(ag Interface) (string, error) {
+		retriever, ok := ag.(ArtistURLRetriever)
 		if !ok {
-			continue
+			return "", ErrNotFound
 		}
-		url, err := agent.GetArtistURL(ctx, id, name, mbid)
-		if url != "" && err == nil {
-			log.Debug(ctx, "Got External Url", "agent", ag.AgentName(), "artist", name, "url", url, "elapsed", time.Since(start))
-			return url, nil
-		}
-	}
-	return "", ErrNotFound
+		return retriever.GetArtistURL(ctx, id, name, mbid)
+	})
 }
 
 func (a *Agents) GetArtistBiography(ctx context.Context, id, name, mbid string) (string, error) {
@@ -113,24 +165,18 @@ func (a *Agents) GetArtistBiography(ctx context.Context, id, name, mbid string)
 	case consts.VariousArtistsID:
 		return "", nil
 	}
-	start := time.Now()
-	for _, ag := range a.agents {
-		if utils.IsCtxDone(ctx) {
-			break
-		}
-		agent, ok := ag.(ArtistBiographyRetriever)
+
+	return callAgentMethod(ctx, a, "GetArtistBiography", func(ag Interface) (string, error) {
+		retriever, ok := ag.(ArtistBiographyRetriever)
 		if !ok {
-			continue
+			return "", ErrNotFound
 		}
-		bio, err := agent.GetArtistBiography(ctx, id, name, mbid)
-		if err == nil {
-			log.Debug(ctx, "Got Biography", "agent", ag.AgentName(), "artist", name, "len", len(bio), "elapsed", time.Since(start))
-			return bio, nil
-		}
-	}
-	return "", ErrNotFound
+		return retriever.GetArtistBiography(ctx, id, name, mbid)
+	})
 }
 
+// GetSimilarArtists returns similar artists by id, name, and/or mbid. Because some artists returned from an enabled
+// agent may not exist in the database, return at most limit * conf.Server.DevExternalArtistFetchMultiplier items.
 func (a *Agents) GetSimilarArtists(ctx context.Context, id, name, mbid string, limit int) ([]Artist, error) {
 	switch id {
 	case consts.UnknownArtistID:
@@ -138,16 +184,23 @@ func (a *Agents) GetSimilarArtists(ctx context.Context, id, name, mbid string, l
 	case consts.VariousArtistsID:
 		return nil, nil
 	}
+
+	overLimit := int(float64(limit) * conf.Server.DevExternalArtistFetchMultiplier)
+
 	start := time.Now()
-	for _, ag := range a.agents {
+	for _, enabledAgent := range a.getEnabledAgentNames() {
+		ag := a.getAgent(enabledAgent)
+		if ag == nil {
+			continue
+		}
 		if utils.IsCtxDone(ctx) {
 			break
 		}
-		agent, ok := ag.(ArtistSimilarRetriever)
+		retriever, ok := ag.(ArtistSimilarRetriever)
 		if !ok {
 			continue
 		}
-		similar, err := agent.GetSimilarArtists(ctx, id, name, mbid, limit)
+		similar, err := retriever.GetSimilarArtists(ctx, id, name, mbid, overLimit)
 		if len(similar) > 0 && err == nil {
 			if log.IsGreaterOrEqualTo(log.LevelTrace) {
 				log.Debug(ctx, "Got Similar Artists", "agent", ag.AgentName(), "artist", name, "similar", similar, "elapsed", time.Since(start))
@@ -167,24 +220,18 @@ func (a *Agents) GetArtistImages(ctx context.Context, id, name, mbid string) ([]
 	case consts.VariousArtistsID:
 		return nil, nil
 	}
-	start := time.Now()
-	for _, ag := range a.agents {
-		if utils.IsCtxDone(ctx) {
-			break
-		}
-		agent, ok := ag.(ArtistImageRetriever)
+
+	return callAgentSliceMethod(ctx, a, "GetArtistImages", func(ag Interface) ([]ExternalImage, error) {
+		retriever, ok := ag.(ArtistImageRetriever)
 		if !ok {
-			continue
+			return nil, ErrNotFound
 		}
-		images, err := agent.GetArtistImages(ctx, id, name, mbid)
-		if len(images) > 0 && err == nil {
-			log.Debug(ctx, "Got Images", "agent", ag.AgentName(), "artist", name, "images", images, "elapsed", time.Since(start))
-			return images, nil
-		}
-	}
-	return nil, ErrNotFound
+		return retriever.GetArtistImages(ctx, id, name, mbid)
+	})
 }
 
+// GetArtistTopSongs returns top songs by id, name, and/or mbid. Because some songs returned from an enabled
+// agent may not exist in the database, return at most limit * conf.Server.DevExternalArtistFetchMultiplier items.
 func (a *Agents) GetArtistTopSongs(ctx context.Context, id, artistName, mbid string, count int) ([]Song, error) {
 	switch id {
 	case consts.UnknownArtistID:
@@ -192,42 +239,130 @@ func (a *Agents) GetArtistTopSongs(ctx context.Context, id, artistName, mbid str
 	case consts.VariousArtistsID:
 		return nil, nil
 	}
-	start := time.Now()
-	for _, ag := range a.agents {
-		if utils.IsCtxDone(ctx) {
-			break
-		}
-		agent, ok := ag.(ArtistTopSongsRetriever)
+
+	overLimit := int(float64(count) * conf.Server.DevExternalArtistFetchMultiplier)
+
+	return callAgentSliceMethod(ctx, a, "GetArtistTopSongs", func(ag Interface) ([]Song, error) {
+		retriever, ok := ag.(ArtistTopSongsRetriever)
 		if !ok {
-			continue
+			return nil, ErrNotFound
 		}
-		songs, err := agent.GetArtistTopSongs(ctx, id, artistName, mbid, count)
-		if len(songs) > 0 && err == nil {
-			log.Debug(ctx, "Got Top Songs", "agent", ag.AgentName(), "artist", artistName, "songs", songs, "elapsed", time.Since(start))
-			return songs, nil
-		}
-	}
-	return nil, ErrNotFound
+		return retriever.GetArtistTopSongs(ctx, id, artistName, mbid, overLimit)
+	})
 }
 
 func (a *Agents) GetAlbumInfo(ctx context.Context, name, artist, mbid string) (*AlbumInfo, error) {
 	if name == consts.UnknownAlbum {
 		return nil, ErrNotFound
 	}
+
+	return callAgentMethod(ctx, a, "GetAlbumInfo", func(ag Interface) (*AlbumInfo, error) {
+		retriever, ok := ag.(AlbumInfoRetriever)
+		if !ok {
+			return nil, ErrNotFound
+		}
+		return retriever.GetAlbumInfo(ctx, name, artist, mbid)
+	})
+}
+
+func (a *Agents) GetAlbumImages(ctx context.Context, name, artist, mbid string) ([]ExternalImage, error) {
+	if name == consts.UnknownAlbum {
+		return nil, ErrNotFound
+	}
+
+	return callAgentSliceMethod(ctx, a, "GetAlbumImages", func(ag Interface) ([]ExternalImage, error) {
+		retriever, ok := ag.(AlbumImageRetriever)
+		if !ok {
+			return nil, ErrNotFound
+		}
+		return retriever.GetAlbumImages(ctx, name, artist, mbid)
+	})
+}
+
+// GetSimilarSongsByTrack returns similar songs for a given track.
+func (a *Agents) GetSimilarSongsByTrack(ctx context.Context, id, name, artist, mbid string, count int) ([]Song, error) {
+	return callAgentSliceMethod(ctx, a, "GetSimilarSongsByTrack", func(ag Interface) ([]Song, error) {
+		retriever, ok := ag.(SimilarSongsByTrackRetriever)
+		if !ok {
+			return nil, ErrNotFound
+		}
+		return retriever.GetSimilarSongsByTrack(ctx, id, name, artist, mbid, count)
+	})
+}
+
+// GetSimilarSongsByAlbum returns similar songs for a given album.
+func (a *Agents) GetSimilarSongsByAlbum(ctx context.Context, id, name, artist, mbid string, count int) ([]Song, error) {
+	return callAgentSliceMethod(ctx, a, "GetSimilarSongsByAlbum", func(ag Interface) ([]Song, error) {
+		retriever, ok := ag.(SimilarSongsByAlbumRetriever)
+		if !ok {
+			return nil, ErrNotFound
+		}
+		return retriever.GetSimilarSongsByAlbum(ctx, id, name, artist, mbid, count)
+	})
+}
+
+// GetSimilarSongsByArtist returns similar songs for a given artist.
+func (a *Agents) GetSimilarSongsByArtist(ctx context.Context, id, name, mbid string, count int) ([]Song, error) {
+	switch id {
+	case consts.UnknownArtistID:
+		return nil, ErrNotFound
+	case consts.VariousArtistsID:
+		return nil, nil
+	}
+
+	return callAgentSliceMethod(ctx, a, "GetSimilarSongsByArtist", func(ag Interface) ([]Song, error) {
+		retriever, ok := ag.(SimilarSongsByArtistRetriever)
+		if !ok {
+			return nil, ErrNotFound
+		}
+		return retriever.GetSimilarSongsByArtist(ctx, id, name, mbid, count)
+	})
+}
+
+func callAgentMethod[T comparable](ctx context.Context, agents *Agents, methodName string, fn func(Interface) (T, error)) (T, error) {
+	var zero T
 	start := time.Now()
-	for _, ag := range a.agents {
+	for _, enabledAgent := range agents.getEnabledAgentNames() {
+		ag := agents.getAgent(enabledAgent)
+		if ag == nil {
+			continue
+		}
 		if utils.IsCtxDone(ctx) {
 			break
 		}
-		agent, ok := ag.(AlbumInfoRetriever)
-		if !ok {
+		result, err := fn(ag)
+		if err != nil {
+			log.Trace(ctx, "Agent method call error", "method", methodName, "agent", ag.AgentName(), "error", err)
 			continue
 		}
-		album, err := agent.GetAlbumInfo(ctx, name, artist, mbid)
-		if err == nil {
-			log.Debug(ctx, "Got Album Info", "agent", ag.AgentName(), "album", name, "artist", artist,
-				"mbid", mbid, "elapsed", time.Since(start))
-			return album, nil
+
+		if result != zero {
+			log.Debug(ctx, "Got result", "method", methodName, "agent", ag.AgentName(), "elapsed", time.Since(start))
+			return result, nil
+		}
+	}
+	return zero, ErrNotFound
+}
+
+func callAgentSliceMethod[T any](ctx context.Context, agents *Agents, methodName string, fn func(Interface) ([]T, error)) ([]T, error) {
+	start := time.Now()
+	for _, enabledAgent := range agents.getEnabledAgentNames() {
+		ag := agents.getAgent(enabledAgent)
+		if ag == nil {
+			continue
+		}
+		if utils.IsCtxDone(ctx) {
+			break
+		}
+		results, err := fn(ag)
+		if err != nil {
+			log.Trace(ctx, "Agent method call error", "method", methodName, "agent", ag.AgentName(), "error", err)
+			continue
+		}
+
+		if len(results) > 0 {
+			log.Debug(ctx, "Got results", "method", methodName, "agent", ag.AgentName(), "count", len(results), "elapsed", time.Since(start))
+			return results, nil
 		}
 	}
 	return nil, ErrNotFound
@@ -241,3 +376,7 @@ var _ ArtistSimilarRetriever = (*Agents)(nil)
 var _ ArtistImageRetriever = (*Agents)(nil)
 var _ ArtistTopSongsRetriever = (*Agents)(nil)
 var _ AlbumInfoRetriever = (*Agents)(nil)
+var _ AlbumImageRetriever = (*Agents)(nil)
+var _ SimilarSongsByTrackRetriever = (*Agents)(nil)
+var _ SimilarSongsByAlbumRetriever = (*Agents)(nil)
+var _ SimilarSongsByArtistRetriever = (*Agents)(nil)

core/agents/agents_plugin_test.go

@@ -0,0 +1,281 @@
+package agents
+
+import (
+	"context"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils/slice"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// MockPluginLoader implements PluginLoader for testing
+type MockPluginLoader struct {
+	pluginNames     []string
+	loadedAgents    map[string]*MockAgent
+	pluginCallCount map[string]int
+}
+
+func NewMockPluginLoader() *MockPluginLoader {
+	return &MockPluginLoader{
+		pluginNames:     []string{},
+		loadedAgents:    make(map[string]*MockAgent),
+		pluginCallCount: make(map[string]int),
+	}
+}
+
+func (m *MockPluginLoader) PluginNames(serviceName string) []string {
+	return m.pluginNames
+}
+
+func (m *MockPluginLoader) LoadMediaAgent(name string) (Interface, bool) {
+	m.pluginCallCount[name]++
+	agent, exists := m.loadedAgents[name]
+	return agent, exists
+}
+
+// MockAgent is a mock agent implementation for testing
+type MockAgent struct {
+	name string
+	mbid string
+}
+
+func (m *MockAgent) AgentName() string {
+	return m.name
+}
+
+func (m *MockAgent) GetArtistMBID(ctx context.Context, id string, name string) (string, error) {
+	return m.mbid, nil
+}
+
+var _ Interface = (*MockAgent)(nil)
+var _ ArtistMBIDRetriever = (*MockAgent)(nil)
+
+var _ PluginLoader = (*MockPluginLoader)(nil)
+
+var _ = Describe("Agents with Plugin Loading", func() {
+	var mockLoader *MockPluginLoader
+	var agents *Agents
+
+	BeforeEach(func() {
+		mockLoader = NewMockPluginLoader()
+
+		// Create the agents instance with our mock loader
+		agents = createAgents(nil, mockLoader)
+	})
+
+	Context("Dynamic agent discovery", func() {
+		It("should include ONLY local agent when no config is specified", func() {
+			// Ensure no specific agents are configured
+			conf.Server.Agents = ""
+
+			// Add some plugin agents that should be ignored
+			mockLoader.pluginNames = append(mockLoader.pluginNames, "plugin_agent", "another_plugin")
+
+			// Should only include the local agent
+			enabledAgents := agents.getEnabledAgentNames()
+			Expect(enabledAgents).To(HaveLen(1))
+			Expect(enabledAgents[0].name).To(Equal(LocalAgentName))
+			Expect(enabledAgents[0].isPlugin).To(BeFalse()) // LocalAgent is built-in, not plugin
+		})
+
+		It("should NOT include plugin agents when no config is specified", func() {
+			// Ensure no specific agents are configured
+			conf.Server.Agents = ""
+
+			// Add a plugin agent
+			mockLoader.pluginNames = append(mockLoader.pluginNames, "plugin_agent")
+
+			// Should only include the local agent
+			enabledAgents := agents.getEnabledAgentNames()
+			Expect(enabledAgents).To(HaveLen(1))
+			Expect(enabledAgents[0].name).To(Equal(LocalAgentName))
+			Expect(enabledAgents[0].isPlugin).To(BeFalse()) // LocalAgent is built-in, not plugin
+		})
+
+		It("should include plugin agents in the enabled agents list ONLY when explicitly configured", func() {
+			// Add a plugin agent
+			mockLoader.pluginNames = append(mockLoader.pluginNames, "plugin_agent")
+
+			// With no config, should not include plugin
+			conf.Server.Agents = ""
+			enabledAgents := agents.getEnabledAgentNames()
+			Expect(enabledAgents).To(HaveLen(1))
+			Expect(enabledAgents[0].name).To(Equal(LocalAgentName))
+
+			// When explicitly configured, should include plugin
+			conf.Server.Agents = "plugin_agent"
+			enabledAgents = agents.getEnabledAgentNames()
+			var agentNames []string
+			var pluginAgentFound bool
+			for _, agent := range enabledAgents {
+				agentNames = append(agentNames, agent.name)
+				if agent.name == "plugin_agent" {
+					pluginAgentFound = true
+					Expect(agent.isPlugin).To(BeTrue()) // plugin_agent is a plugin
+				}
+			}
+			Expect(agentNames).To(ContainElements(LocalAgentName, "plugin_agent"))
+			Expect(pluginAgentFound).To(BeTrue())
+		})
+
+		It("should only include configured plugin agents when config is specified", func() {
+			// Add two plugin agents
+			mockLoader.pluginNames = append(mockLoader.pluginNames, "plugin_one", "plugin_two")
+
+			// Configure only one of them
+			conf.Server.Agents = "plugin_one"
+
+			// Verify only the configured one is included
+			enabledAgents := agents.getEnabledAgentNames()
+			var agentNames []string
+			var pluginOneFound bool
+			for _, agent := range enabledAgents {
+				agentNames = append(agentNames, agent.name)
+				if agent.name == "plugin_one" {
+					pluginOneFound = true
+					Expect(agent.isPlugin).To(BeTrue()) // plugin_one is a plugin
+				}
+			}
+			Expect(agentNames).To(ContainElements(LocalAgentName, "plugin_one"))
+			Expect(agentNames).NotTo(ContainElement("plugin_two"))
+			Expect(pluginOneFound).To(BeTrue())
+		})
+
+		It("should load plugin agents on demand", func() {
+			ctx := context.Background()
+
+			// Configure to use our plugin
+			conf.Server.Agents = "plugin_agent"
+
+			// Add a plugin agent
+			mockLoader.pluginNames = append(mockLoader.pluginNames, "plugin_agent")
+			mockLoader.loadedAgents["plugin_agent"] = &MockAgent{
+				name: "plugin_agent",
+				mbid: "plugin-mbid",
+			}
+
+			// Try to get data from it
+			mbid, err := agents.GetArtistMBID(ctx, "123", "Artist")
+
+			Expect(err).ToNot(HaveOccurred())
+			Expect(mbid).To(Equal("plugin-mbid"))
+			Expect(mockLoader.pluginCallCount["plugin_agent"]).To(Equal(1))
+		})
+
+		It("should try both built-in and plugin agents", func() {
+			// Create a mock built-in agent
+			Register("built_in", func(ds model.DataStore) Interface {
+				return &MockAgent{
+					name: "built_in",
+					mbid: "built-in-mbid",
+				}
+			})
+			defer func() {
+				delete(Map, "built_in")
+			}()
+
+			// Configure to use both built-in and plugin
+			conf.Server.Agents = "built_in,plugin_agent"
+
+			// Add a plugin agent
+			mockLoader.pluginNames = append(mockLoader.pluginNames, "plugin_agent")
+			mockLoader.loadedAgents["plugin_agent"] = &MockAgent{
+				name: "plugin_agent",
+				mbid: "plugin-mbid",
+			}
+
+			// Verify that both are in the enabled list
+			enabledAgents := agents.getEnabledAgentNames()
+			var agentNames []string
+			var builtInFound, pluginFound bool
+			for _, agent := range enabledAgents {
+				agentNames = append(agentNames, agent.name)
+				if agent.name == "built_in" {
+					builtInFound = true
+					Expect(agent.isPlugin).To(BeFalse()) // built-in agent
+				}
+				if agent.name == "plugin_agent" {
+					pluginFound = true
+					Expect(agent.isPlugin).To(BeTrue()) // plugin agent
+				}
+			}
+			Expect(agentNames).To(ContainElements("built_in", "plugin_agent", LocalAgentName))
+			Expect(builtInFound).To(BeTrue())
+			Expect(pluginFound).To(BeTrue())
+		})
+
+		It("should respect the order specified in configuration", func() {
+			// Create mock built-in agents
+			Register("agent_a", func(ds model.DataStore) Interface {
+				return &MockAgent{name: "agent_a"}
+			})
+			Register("agent_b", func(ds model.DataStore) Interface {
+				return &MockAgent{name: "agent_b"}
+			})
+			defer func() {
+				delete(Map, "agent_a")
+				delete(Map, "agent_b")
+			}()
+
+			// Add plugin agents
+			mockLoader.pluginNames = append(mockLoader.pluginNames, "plugin_x", "plugin_y")
+
+			// Configure specific order - plugin first, then built-ins
+			conf.Server.Agents = "plugin_y,agent_b,plugin_x,agent_a"
+
+			// Get the agent names
+			enabledAgents := agents.getEnabledAgentNames()
+
+			// Extract just the names to verify the order
+			agentNames := slice.Map(enabledAgents, func(a enabledAgent) string { return a.name })
+
+			// Verify the order matches configuration, with LocalAgentName at the end
+			Expect(agentNames).To(HaveExactElements("plugin_y", "agent_b", "plugin_x", "agent_a", LocalAgentName))
+		})
+
+		It("should NOT call LoadMediaAgent for built-in agents", func() {
+			ctx := context.Background()
+
+			// Create a mock built-in agent
+			Register("builtin_agent", func(ds model.DataStore) Interface {
+				return &MockAgent{
+					name: "builtin_agent",
+					mbid: "builtin-mbid",
+				}
+			})
+			defer func() {
+				delete(Map, "builtin_agent")
+			}()
+
+			// Configure to use only built-in agents
+			conf.Server.Agents = "builtin_agent"
+
+			// Call GetArtistMBID which should only use the built-in agent
+			mbid, err := agents.GetArtistMBID(ctx, "123", "Artist")
+
+			Expect(err).ToNot(HaveOccurred())
+			Expect(mbid).To(Equal("builtin-mbid"))
+
+			// Verify LoadMediaAgent was NEVER called (no plugin loading for built-in agents)
+			Expect(mockLoader.pluginCallCount).To(BeEmpty())
+		})
+
+		It("should NOT call LoadMediaAgent for invalid agent names", func() {
+			ctx := context.Background()
+
+			// Configure with an invalid agent name (not built-in, not a plugin)
+			conf.Server.Agents = "invalid_agent"
+
+			// This should only result in using the local agent (as the invalid one is ignored)
+			_, err := agents.GetArtistMBID(ctx, "123", "Artist")
+
+			// Should get ErrNotFound since only local agent is available and it returns not found for this operation
+			Expect(err).To(MatchError(ErrNotFound))
+
+			// Verify LoadMediaAgent was NEVER called for the invalid agent
+			Expect(mockLoader.pluginCallCount).To(BeEmpty())
+		})
+	})
+})

core/agents/agents_test.go

@@ -4,10 +4,10 @@ import (
 	"context"
 	"errors"
 
+	"github.com/navidrome/navidrome/conf/configtest"
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/tests"
-	"github.com/navidrome/navidrome/utils/slice"
 
 	"github.com/navidrome/navidrome/conf"
 	. "github.com/onsi/ginkgo/v2"
@@ -20,6 +20,7 @@ var _ = Describe("Agents", func() {
 	var ds model.DataStore
 	var mfRepo *tests.MockMediaFileRepo
 	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
 		ctx, cancel = context.WithCancel(context.Background())
 		mfRepo = tests.CreateMockMediaFileRepo()
 		ds = &tests.MockDataStore{MockedMediaFile: mfRepo}
@@ -29,7 +30,7 @@ var _ = Describe("Agents", func() {
 		var ag *Agents
 		BeforeEach(func() {
 			conf.Server.Agents = ""
-			ag = createAgents(ds)
+			ag = createAgents(ds, nil)
 		})
 
 		It("calls the placeholder GetArtistImages", func() {
@@ -49,12 +50,18 @@ var _ = Describe("Agents", func() {
 			Register("disabled", func(model.DataStore) Interface { return nil })
 			Register("empty", func(model.DataStore) Interface { return &emptyAgent{} })
 			conf.Server.Agents = "empty,fake,disabled"
-			ag = createAgents(ds)
+			ag = createAgents(ds, nil)
 			Expect(ag.AgentName()).To(Equal("agents"))
 		})
 
 		It("does not register disabled agents", func() {
-			ags := slice.Map(ag.agents, func(a Interface) string { return a.AgentName() })
+			var ags []string
+			for _, enabledAgent := range ag.getEnabledAgentNames() {
+				agent := ag.getAgent(enabledAgent)
+				if agent != nil {
+					ags = append(ags, agent.AgentName())
+				}
+			}
 			// local agent is always appended to the end of the agents list
 			Expect(ags).To(HaveExactElements("empty", "fake", "local"))
 			Expect(ags).ToNot(ContainElement("disabled"))
@@ -173,6 +180,42 @@ var _ = Describe("Agents", func() {
 				Expect(err).To(MatchError(ErrNotFound))
 				Expect(mock.Args).To(BeEmpty())
 			})
+
+			Context("with multiple image agents", func() {
+				var first *testImageAgent
+				var second *testImageAgent
+
+				BeforeEach(func() {
+					first = &testImageAgent{Name: "imgFail", Err: errors.New("fail")}
+					second = &testImageAgent{Name: "imgOk", Images: []ExternalImage{{URL: "ok", Size: 1}}}
+					Register("imgFail", func(model.DataStore) Interface { return first })
+					Register("imgOk", func(model.DataStore) Interface { return second })
+				})
+
+				It("falls back to the next agent on error", func() {
+					conf.Server.Agents = "imgFail,imgOk"
+					ag = createAgents(ds, nil)
+
+					images, err := ag.GetArtistImages(ctx, "id", "artist", "mbid")
+					Expect(err).ToNot(HaveOccurred())
+					Expect(images).To(Equal([]ExternalImage{{URL: "ok", Size: 1}}))
+					Expect(first.Args).To(HaveExactElements("id", "artist", "mbid"))
+					Expect(second.Args).To(HaveExactElements("id", "artist", "mbid"))
+				})
+
+				It("falls back if the first agent returns no images", func() {
+					first.Err = nil
+					first.Images = []ExternalImage{}
+					conf.Server.Agents = "imgFail,imgOk"
+					ag = createAgents(ds, nil)
+
+					images, err := ag.GetArtistImages(ctx, "id", "artist", "mbid")
+					Expect(err).ToNot(HaveOccurred())
+					Expect(images).To(Equal([]ExternalImage{{URL: "ok", Size: 1}}))
+					Expect(first.Args).To(HaveExactElements("id", "artist", "mbid"))
+					Expect(second.Args).To(HaveExactElements("id", "artist", "mbid"))
+				})
+			})
 		})
 
 		Describe("GetSimilarArtists", func() {
@@ -199,6 +242,7 @@ var _ = Describe("Agents", func() {
 
 		Describe("GetArtistTopSongs", func() {
 			It("returns on first match", func() {
+				conf.Server.DevExternalArtistFetchMultiplier = 1
 				Expect(ag.GetArtistTopSongs(ctx, "123", "test", "mb123", 2)).To(Equal([]Song{{
 					Name: "A Song",
 					MBID: "mbid444",
@@ -206,6 +250,7 @@ var _ = Describe("Agents", func() {
 				Expect(mock.Args).To(HaveExactElements("123", "test", "mb123", 2))
 			})
 			It("skips the agent if it returns an error", func() {
+				conf.Server.DevExternalArtistFetchMultiplier = 1
 				mock.Err = errors.New("error")
 				_, err := ag.GetArtistTopSongs(ctx, "123", "test", "mb123", 2)
 				Expect(err).To(MatchError(ErrNotFound))
@@ -217,6 +262,14 @@ var _ = Describe("Agents", func() {
 				Expect(err).To(MatchError(ErrNotFound))
 				Expect(mock.Args).To(BeEmpty())
 			})
+			It("fetches with multiplier", func() {
+				conf.Server.DevExternalArtistFetchMultiplier = 2
+				Expect(ag.GetArtistTopSongs(ctx, "123", "test", "mb123", 2)).To(Equal([]Song{{
+					Name: "A Song",
+					MBID: "mbid444",
+				}}))
+				Expect(mock.Args).To(HaveExactElements("123", "test", "mb123", 4))
+			})
 		})
 
 		Describe("GetAlbumInfo", func() {
@@ -226,18 +279,6 @@ var _ = Describe("Agents", func() {
 					MBID:        "mbid444",
 					Description: "A Description",
 					URL:         "External URL",
-					Images: []ExternalImage{
-						{
-							Size: 174,
-							URL:  "https://lastfm.freetls.fastly.net/i/u/174s/00000000000000000000000000000000.png",
-						}, {
-							Size: 64,
-							URL:  "https://lastfm.freetls.fastly.net/i/u/64s/00000000000000000000000000000000.png",
-						}, {
-							Size: 34,
-							URL:  "https://lastfm.freetls.fastly.net/i/u/34s/00000000000000000000000000000000.png",
-						},
-					},
 				}))
 				Expect(mock.Args).To(HaveExactElements("album", "artist", "mbid"))
 			})
@@ -254,6 +295,72 @@ var _ = Describe("Agents", func() {
 				Expect(mock.Args).To(BeEmpty())
 			})
 		})
+
+		Describe("GetSimilarSongsByTrack", func() {
+			It("returns on first match", func() {
+				Expect(ag.GetSimilarSongsByTrack(ctx, "123", "test song", "test artist", "mb123", 2)).To(Equal([]Song{{
+					Name: "Similar Song",
+					MBID: "mbid555",
+				}}))
+				Expect(mock.Args).To(HaveExactElements("123", "test song", "test artist", "mb123", 2))
+			})
+			It("skips the agent if it returns an error", func() {
+				mock.Err = errors.New("error")
+				_, err := ag.GetSimilarSongsByTrack(ctx, "123", "test song", "test artist", "mb123", 2)
+				Expect(err).To(MatchError(ErrNotFound))
+				Expect(mock.Args).To(HaveExactElements("123", "test song", "test artist", "mb123", 2))
+			})
+			It("interrupts if the context is canceled", func() {
+				cancel()
+				_, err := ag.GetSimilarSongsByTrack(ctx, "123", "test song", "test artist", "mb123", 2)
+				Expect(err).To(MatchError(ErrNotFound))
+				Expect(mock.Args).To(BeEmpty())
+			})
+		})
+
+		Describe("GetSimilarSongsByAlbum", func() {
+			It("returns on first match", func() {
+				Expect(ag.GetSimilarSongsByAlbum(ctx, "123", "test album", "test artist", "mb123", 2)).To(Equal([]Song{{
+					Name: "Album Similar Song",
+					MBID: "mbid666",
+				}}))
+				Expect(mock.Args).To(HaveExactElements("123", "test album", "test artist", "mb123", 2))
+			})
+			It("skips the agent if it returns an error", func() {
+				mock.Err = errors.New("error")
+				_, err := ag.GetSimilarSongsByAlbum(ctx, "123", "test album", "test artist", "mb123", 2)
+				Expect(err).To(MatchError(ErrNotFound))
+				Expect(mock.Args).To(HaveExactElements("123", "test album", "test artist", "mb123", 2))
+			})
+			It("interrupts if the context is canceled", func() {
+				cancel()
+				_, err := ag.GetSimilarSongsByAlbum(ctx, "123", "test album", "test artist", "mb123", 2)
+				Expect(err).To(MatchError(ErrNotFound))
+				Expect(mock.Args).To(BeEmpty())
+			})
+		})
+
+		Describe("GetSimilarSongsByArtist", func() {
+			It("returns on first match", func() {
+				Expect(ag.GetSimilarSongsByArtist(ctx, "123", "test artist", "mb123", 2)).To(Equal([]Song{{
+					Name: "Artist Similar Song",
+					MBID: "mbid777",
+				}}))
+				Expect(mock.Args).To(HaveExactElements("123", "test artist", "mb123", 2))
+			})
+			It("skips the agent if it returns an error", func() {
+				mock.Err = errors.New("error")
+				_, err := ag.GetSimilarSongsByArtist(ctx, "123", "test artist", "mb123", 2)
+				Expect(err).To(MatchError(ErrNotFound))
+				Expect(mock.Args).To(HaveExactElements("123", "test artist", "mb123", 2))
+			})
+			It("interrupts if the context is canceled", func() {
+				cancel()
+				_, err := ag.GetSimilarSongsByArtist(ctx, "123", "test artist", "mb123", 2)
+				Expect(err).To(MatchError(ErrNotFound))
+				Expect(mock.Args).To(BeEmpty())
+			})
+		})
 	})
 })
 
@@ -333,21 +440,42 @@ func (a *mockAgent) GetAlbumInfo(ctx context.Context, name, artist, mbid string)
 		MBID:        "mbid444",
 		Description: "A Description",
 		URL:         "External URL",
-		Images: []ExternalImage{
-			{
-				Size: 174,
-				URL:  "https://lastfm.freetls.fastly.net/i/u/174s/00000000000000000000000000000000.png",
-			}, {
-				Size: 64,
-				URL:  "https://lastfm.freetls.fastly.net/i/u/64s/00000000000000000000000000000000.png",
-			}, {
-				Size: 34,
-				URL:  "https://lastfm.freetls.fastly.net/i/u/34s/00000000000000000000000000000000.png",
-			},
-		},
 	}, nil
 }
 
+func (a *mockAgent) GetSimilarSongsByTrack(_ context.Context, id, name, artist, mbid string, count int) ([]Song, error) {
+	a.Args = []interface{}{id, name, artist, mbid, count}
+	if a.Err != nil {
+		return nil, a.Err
+	}
+	return []Song{{
+		Name: "Similar Song",
+		MBID: "mbid555",
+	}}, nil
+}
+
+func (a *mockAgent) GetSimilarSongsByAlbum(_ context.Context, id, name, artist, mbid string, count int) ([]Song, error) {
+	a.Args = []interface{}{id, name, artist, mbid, count}
+	if a.Err != nil {
+		return nil, a.Err
+	}
+	return []Song{{
+		Name: "Album Similar Song",
+		MBID: "mbid666",
+	}}, nil
+}
+
+func (a *mockAgent) GetSimilarSongsByArtist(_ context.Context, id, name, mbid string, count int) ([]Song, error) {
+	a.Args = []interface{}{id, name, mbid, count}
+	if a.Err != nil {
+		return nil, a.Err
+	}
+	return []Song{{
+		Name: "Artist Similar Song",
+		MBID: "mbid777",
+	}}, nil
+}
+
 type emptyAgent struct {
 	Interface
 }
@@ -355,3 +483,17 @@ type emptyAgent struct {
 func (e *emptyAgent) AgentName() string {
 	return "empty"
 }
+
+type testImageAgent struct {
+	Name   string
+	Images []ExternalImage
+	Err    error
+	Args   []interface{}
+}
+
+func (t *testImageAgent) AgentName() string { return t.Name }
+
+func (t *testImageAgent) GetArtistImages(_ context.Context, id, name, mbid string) ([]ExternalImage, error) {
+	t.Args = []interface{}{id, name, mbid}
+	return t.Images, t.Err
+}

core/agents/interfaces.go

@@ -13,15 +13,16 @@ type Interface interface {
 	AgentName() string
 }
 
+// AlbumInfo contains album metadata (no images)
 type AlbumInfo struct {
 	Name        string
 	MBID        string
 	Description string
 	URL         string
-	Images      []ExternalImage
 }
 
 type Artist struct {
+	ID   string
 	Name string
 	MBID string
 }
@@ -32,19 +33,31 @@ type ExternalImage struct {
 }
 
 type Song struct {
-	Name string
-	MBID string
+	ID         string
+	Name       string
+	MBID       string
+	ISRC       string
+	Artist     string
+	ArtistMBID string
+	Album      string
+	AlbumMBID  string
+	Duration   uint32 // Duration in milliseconds, 0 means unknown
 }
 
 var (
 	ErrNotFound = errors.New("not found")
 )
 
-// TODO Break up this interface in more specific methods, like artists
+// AlbumInfoRetriever provides album info (no images)
 type AlbumInfoRetriever interface {
 	GetAlbumInfo(ctx context.Context, name, artist, mbid string) (*AlbumInfo, error)
 }
 
+// AlbumImageRetriever provides album images
+type AlbumImageRetriever interface {
+	GetAlbumImages(ctx context.Context, name, artist, mbid string) ([]ExternalImage, error)
+}
+
 type ArtistMBIDRetriever interface {
 	GetArtistMBID(ctx context.Context, id string, name string) (string, error)
 }
@@ -69,6 +82,41 @@ type ArtistTopSongsRetriever interface {
 	GetArtistTopSongs(ctx context.Context, id, artistName, mbid string, count int) ([]Song, error)
 }
 
+// SimilarSongsByTrackRetriever provides similar songs based on a specific track
+type SimilarSongsByTrackRetriever interface {
+	// GetSimilarSongsByTrack returns songs similar to the given track.
+	// Parameters:
+	//   - id: local mediafile ID
+	//   - name: track title
+	//   - artist: artist name
+	//   - mbid: MusicBrainz recording ID (may be empty)
+	//   - count: maximum number of results
+	GetSimilarSongsByTrack(ctx context.Context, id, name, artist, mbid string, count int) ([]Song, error)
+}
+
+// SimilarSongsByAlbumRetriever provides similar songs based on an album
+type SimilarSongsByAlbumRetriever interface {
+	// GetSimilarSongsByAlbum returns songs similar to tracks on the given album.
+	// Parameters:
+	//   - id: local album ID
+	//   - name: album name
+	//   - artist: album artist name
+	//   - mbid: MusicBrainz release ID (may be empty)
+	//   - count: maximum number of results
+	GetSimilarSongsByAlbum(ctx context.Context, id, name, artist, mbid string, count int) ([]Song, error)
+}
+
+// SimilarSongsByArtistRetriever provides similar songs based on an artist
+type SimilarSongsByArtistRetriever interface {
+	// GetSimilarSongsByArtist returns songs similar to the artist's catalog.
+	// Parameters:
+	//   - id: local artist ID
+	//   - name: artist name
+	//   - mbid: MusicBrainz artist ID (may be empty)
+	//   - count: maximum number of results
+	GetSimilarSongsByArtist(ctx context.Context, id, name, mbid string, count int) ([]Song, error)
+}
+
 var Map map[string]Constructor
 
 func Register(name string, init Constructor) {

core/artwork/artwork_internal_test.go

@@ -302,6 +302,33 @@ var _ = Describe("Artwork", func() {
 				Entry("landscape jpg image", "jpg", true, 200),
 			)
 		})
+		When("Requested size is larger than original", func() {
+			It("clamps size to original dimensions", func() {
+				conf.Server.CoverArtPriority = "front.png"
+				// front.png is 16x16, requesting 99999 should return at original size
+				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 99999, false)
+				Expect(err).ToNot(HaveOccurred())
+
+				img, _, err := image.Decode(r)
+				Expect(err).ToNot(HaveOccurred())
+				// Should be clamped to original size (16), not 99999
+				Expect(img.Bounds().Size().X).To(Equal(16))
+				Expect(img.Bounds().Size().Y).To(Equal(16))
+			})
+
+			It("clamps square size to original dimensions", func() {
+				conf.Server.CoverArtPriority = "front.png"
+				// front.png is 16x16, requesting 99999 with square should return 16x16 square
+				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 99999, true)
+				Expect(err).ToNot(HaveOccurred())
+
+				img, _, err := image.Decode(r)
+				Expect(err).ToNot(HaveOccurred())
+				// Should be clamped to original size (16), not 99999
+				Expect(img.Bounds().Size().X).To(Equal(16))
+				Expect(img.Bounds().Size().Y).To(Equal(16))
+			})
+		})
 	})
 })
 

core/artwork/cache_warmer.go

@@ -96,8 +96,11 @@ func (a *cacheWarmer) run(ctx context.Context) {
 
 		// If cache not available, keep waiting
 		if !a.cache.Available(ctx) {
-			if len(a.buffer) > 0 {
-				log.Trace(ctx, "Cache not available, buffering precache request", "bufferLen", len(a.buffer))
+			a.mutex.Lock()
+			bufferLen := len(a.buffer)
+			a.mutex.Unlock()
+			if bufferLen > 0 {
+				log.Trace(ctx, "Cache not available, buffering precache request", "bufferLen", bufferLen)
 			}
 			continue
 		}

core/artwork/cache_warmer_test.go

@@ -80,6 +80,7 @@ var _ = Describe("CacheWarmer", func() {
 		})
 
 		It("adds multiple items to buffer", func() {
+			fc.SetReady(false) // Make cache unavailable so items stay in buffer
 			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
 			cw.PreCache(model.MustParseArtworkID("al-1"))
 			cw.PreCache(model.MustParseArtworkID("al-2"))
@@ -89,6 +90,7 @@ var _ = Describe("CacheWarmer", func() {
 		})
 
 		It("deduplicates items in buffer", func() {
+			fc.SetReady(false) // Make cache unavailable so items stay in buffer
 			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
 			cw.PreCache(model.MustParseArtworkID("al-1"))
 			cw.PreCache(model.MustParseArtworkID("al-1"))
@@ -214,3 +216,7 @@ func (f *mockFileCache) SetDisabled(v bool) {
 	f.disabled.Store(v)
 	f.ready.Store(true)
 }
+
+func (f *mockFileCache) SetReady(v bool) {
+	f.ready.Store(v)
+}

core/artwork/reader_album.go

@@ -1,6 +1,7 @@
 package artwork
 
 import (
+	"cmp"
 	"context"
 	"crypto/md5"
 	"fmt"
@@ -11,6 +12,7 @@ import (
 	"time"
 
 	"github.com/Masterminds/squirrel"
+	"github.com/maruel/natural"
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/core"
 	"github.com/navidrome/navidrome/core/external"
@@ -116,8 +118,30 @@ func loadAlbumFoldersPaths(ctx context.Context, ds model.DataStore, albums ...mo
 	}
 
 	// Sort image files to ensure consistent selection of cover art
-	// This prioritizes files from lower-numbered disc folders by sorting the paths
-	slices.Sort(imgFiles)
+	// This prioritizes files without numeric suffixes (e.g., cover.jpg over cover.1.jpg)
+	// by comparing base filenames without extensions
+	slices.SortFunc(imgFiles, compareImageFiles)
 
 	return paths, imgFiles, &updatedAt, nil
 }
+
+// compareImageFiles compares two image file paths for sorting.
+// It extracts the base filename (without extension) and compares case-insensitively.
+// This ensures that "cover.jpg" sorts before "cover.1.jpg" since "cover" < "cover.1".
+// Note: This function is called O(n log n) times during sorting, but in practice albums
+// typically have only 1-20 image files, making the repeated string operations negligible.
+func compareImageFiles(a, b string) int {
+	// Case-insensitive comparison
+	a = strings.ToLower(a)
+	b = strings.ToLower(b)
+
+	// Extract base filenames without extensions
+	baseA := strings.TrimSuffix(filepath.Base(a), filepath.Ext(a))
+	baseB := strings.TrimSuffix(filepath.Base(b), filepath.Ext(b))
+
+	// Compare base names first, then full paths if equal
+	return cmp.Or(
+		natural.Compare(baseA, baseB),
+		natural.Compare(a, b),
+	)
+}

core/artwork/reader_album_test.go

@@ -27,26 +27,7 @@ var _ = Describe("Album Artwork Reader", func() {
 			expectedAt = now.Add(5 * time.Minute)
 
 			// Set up the test folders with image files
-			repo = &fakeFolderRepo{
-				result: []model.Folder{
-					{
-						Path:            "Artist/Album/Disc1",
-						ImagesUpdatedAt: expectedAt,
-						ImageFiles:      []string{"cover.jpg", "back.jpg"},
-					},
-					{
-						Path:            "Artist/Album/Disc2",
-						ImagesUpdatedAt: now,
-						ImageFiles:      []string{"cover.jpg"},
-					},
-					{
-						Path:            "Artist/Album/Disc10",
-						ImagesUpdatedAt: now,
-						ImageFiles:      []string{"cover.jpg"},
-					},
-				},
-				err: nil,
-			}
+			repo = &fakeFolderRepo{}
 			ds = &fakeDataStore{
 				folderRepo: repo,
 			}
@@ -58,19 +39,82 @@ var _ = Describe("Album Artwork Reader", func() {
 		})
 
 		It("returns sorted image files", func() {
+			repo.result = []model.Folder{
+				{
+					Path:            "Artist/Album/Disc1",
+					ImagesUpdatedAt: expectedAt,
+					ImageFiles:      []string{"cover.jpg", "back.jpg", "cover.1.jpg"},
+				},
+				{
+					Path:            "Artist/Album/Disc2",
+					ImagesUpdatedAt: now,
+					ImageFiles:      []string{"cover.jpg"},
+				},
+				{
+					Path:            "Artist/Album/Disc10",
+					ImagesUpdatedAt: now,
+					ImageFiles:      []string{"cover.jpg"},
+				},
+			}
+
 			_, imgFiles, imagesUpdatedAt, err := loadAlbumFoldersPaths(ctx, ds, album)
 
 			Expect(err).ToNot(HaveOccurred())
 			Expect(*imagesUpdatedAt).To(Equal(expectedAt))
 
-			// Check that image files are sorted alphabetically
-			Expect(imgFiles).To(HaveLen(4))
+			// Check that image files are sorted by base name (without extension)
+			Expect(imgFiles).To(HaveLen(5))
 
-			// The files should be sorted by full path
+			// Files should be sorted by base filename without extension, then by full path
+			// "back" < "cover", so back.jpg comes first
+			// Then all cover.jpg files, sorted by path
 			Expect(imgFiles[0]).To(Equal(filepath.FromSlash("Artist/Album/Disc1/back.jpg")))
 			Expect(imgFiles[1]).To(Equal(filepath.FromSlash("Artist/Album/Disc1/cover.jpg")))
-			Expect(imgFiles[2]).To(Equal(filepath.FromSlash("Artist/Album/Disc10/cover.jpg")))
-			Expect(imgFiles[3]).To(Equal(filepath.FromSlash("Artist/Album/Disc2/cover.jpg")))
+			Expect(imgFiles[2]).To(Equal(filepath.FromSlash("Artist/Album/Disc2/cover.jpg")))
+			Expect(imgFiles[3]).To(Equal(filepath.FromSlash("Artist/Album/Disc10/cover.jpg")))
+			Expect(imgFiles[4]).To(Equal(filepath.FromSlash("Artist/Album/Disc1/cover.1.jpg")))
+		})
+
+		It("prioritizes files without numeric suffixes", func() {
+			// Test case for issue #4683: cover.jpg should come before cover.1.jpg
+			repo.result = []model.Folder{
+				{
+					Path:            "Artist/Album",
+					ImagesUpdatedAt: now,
+					ImageFiles:      []string{"cover.1.jpg", "cover.jpg", "cover.2.jpg"},
+				},
+			}
+
+			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+			Expect(err).ToNot(HaveOccurred())
+			Expect(imgFiles).To(HaveLen(3))
+
+			// cover.jpg should come first because "cover" < "cover.1" < "cover.2"
+			Expect(imgFiles[0]).To(Equal(filepath.FromSlash("Artist/Album/cover.jpg")))
+			Expect(imgFiles[1]).To(Equal(filepath.FromSlash("Artist/Album/cover.1.jpg")))
+			Expect(imgFiles[2]).To(Equal(filepath.FromSlash("Artist/Album/cover.2.jpg")))
+		})
+
+		It("handles case-insensitive sorting", func() {
+			// Test that Cover.jpg and cover.jpg are treated as equivalent
+			repo.result = []model.Folder{
+				{
+					Path:            "Artist/Album",
+					ImagesUpdatedAt: now,
+					ImageFiles:      []string{"Folder.jpg", "cover.jpg", "BACK.jpg"},
+				},
+			}
+
+			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+			Expect(err).ToNot(HaveOccurred())
+			Expect(imgFiles).To(HaveLen(3))
+
+			// Files should be sorted case-insensitively: BACK, cover, Folder
+			Expect(imgFiles[0]).To(Equal(filepath.FromSlash("Artist/Album/BACK.jpg")))
+			Expect(imgFiles[1]).To(Equal(filepath.FromSlash("Artist/Album/cover.jpg")))
+			Expect(imgFiles[2]).To(Equal(filepath.FromSlash("Artist/Album/Folder.jpg")))
 		})
 	})
 })

core/artwork/reader_artist.go

@@ -8,6 +8,7 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 	"time"
 
@@ -20,6 +21,12 @@ import (
 	"github.com/navidrome/navidrome/utils/str"
 )
 
+const (
+	// maxArtistFolderTraversalDepth defines how many directory levels to search
+	// when looking for artist images (artist folder + parent directories)
+	maxArtistFolderTraversalDepth = 3
+)
+
 type artistReader struct {
 	cacheKey
 	a            *artwork
@@ -108,36 +115,63 @@ func (a *artistReader) fromArtistArtPriority(ctx context.Context, priority strin
 
 func fromArtistFolder(ctx context.Context, artistFolder string, pattern string) sourceFunc {
 	return func() (io.ReadCloser, string, error) {
-		fsys := os.DirFS(artistFolder)
-		matches, err := fs.Glob(fsys, pattern)
-		if err != nil {
-			log.Warn(ctx, "Error matching artist image pattern", "pattern", pattern, "folder", artistFolder)
-			return nil, "", err
-		}
-		if len(matches) == 0 {
-			return nil, "", fmt.Errorf(`no matches for '%s' in '%s'`, pattern, artistFolder)
-		}
-		for _, m := range matches {
-			filePath := filepath.Join(artistFolder, m)
-			if !model.IsImageFile(m) {
-				continue
+		current := artistFolder
+		for i := 0; i < maxArtistFolderTraversalDepth; i++ {
+			if reader, path, err := findImageInFolder(ctx, current, pattern); err == nil {
+				return reader, path, nil
 			}
-			f, err := os.Open(filePath)
-			if err != nil {
-				log.Warn(ctx, "Could not open cover art file", "file", filePath, err)
-				return nil, "", err
+
+			parent := filepath.Dir(current)
+			if parent == current {
+				break
 			}
-			return f, filePath, nil
+			current = parent
 		}
-		return nil, "", nil
+		return nil, "", fmt.Errorf(`no matches for '%s' in '%s' or its parent directories`, pattern, artistFolder)
 	}
 }
 
+func findImageInFolder(ctx context.Context, folder, pattern string) (io.ReadCloser, string, error) {
+	log.Trace(ctx, "looking for artist image", "pattern", pattern, "folder", folder)
+	fsys := os.DirFS(folder)
+	matches, err := fs.Glob(fsys, pattern)
+	if err != nil {
+		log.Warn(ctx, "Error matching artist image pattern", "pattern", pattern, "folder", folder, err)
+		return nil, "", err
+	}
+
+	// Filter to valid image files
+	var imagePaths []string
+	for _, m := range matches {
+		if !model.IsImageFile(m) {
+			continue
+		}
+		imagePaths = append(imagePaths, m)
+	}
+
+	// Sort image files by prioritizing base filenames without numeric
+	// suffixes (e.g., artist.jpg before artist.1.jpg)
+	slices.SortFunc(imagePaths, compareImageFiles)
+
+	// Try to open files in sorted order
+	for _, p := range imagePaths {
+		filePath := filepath.Join(folder, p)
+		f, err := os.Open(filePath)
+		if err != nil {
+			log.Warn(ctx, "Could not open cover art file", "file", filePath, err)
+			continue
+		}
+		return f, filePath, nil
+	}
+
+	return nil, "", fmt.Errorf(`no matches for '%s' in '%s'`, pattern, folder)
+}
+
 func loadArtistFolder(ctx context.Context, ds model.DataStore, albums model.Albums, paths []string) (string, time.Time, error) {
 	if len(albums) == 0 {
 		return "", time.Time{}, nil
 	}
-	libID := albums[0].LibraryID // Just need one of the albums, as they should all be in the same Library
+	libID := albums[0].LibraryID // Just need one of the albums, as they should all be in the same Library - for now! TODO: Support multiple libraries
 
 	folderPath := str.LongestCommonPrefix(paths)
 	if !strings.HasSuffix(folderPath, string(filepath.Separator)) {

core/artwork/reader_artist_test.go

@@ -3,6 +3,8 @@ package artwork
 import (
 	"context"
 	"errors"
+	"io"
+	"os"
 	"path/filepath"
 	"time"
 
@@ -108,6 +110,309 @@ var _ = Describe("artistArtworkReader", func() {
 			})
 		})
 	})
+
+	var _ = Describe("fromArtistFolder", func() {
+		var (
+			ctx      context.Context
+			tempDir  string
+			testFunc sourceFunc
+		)
+
+		BeforeEach(func() {
+			ctx = context.Background()
+			tempDir = GinkgoT().TempDir()
+		})
+
+		When("artist folder contains matching image", func() {
+			BeforeEach(func() {
+				// Create test structure: /temp/artist/artist.jpg
+				artistDir := filepath.Join(tempDir, "artist")
+				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
+
+				artistImagePath := filepath.Join(artistDir, "artist.jpg")
+				Expect(os.WriteFile(artistImagePath, []byte("fake image data"), 0600)).To(Succeed())
+
+				testFunc = fromArtistFolder(ctx, artistDir, "artist.*")
+			})
+
+			It("finds and returns the image", func() {
+				reader, path, err := testFunc()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(reader).ToNot(BeNil())
+				Expect(path).To(ContainSubstring("artist.jpg"))
+
+				// Verify we can read the content
+				data, err := io.ReadAll(reader)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(string(data)).To(Equal("fake image data"))
+				reader.Close()
+			})
+		})
+
+		When("artist folder is empty but parent contains image", func() {
+			BeforeEach(func() {
+				// Create test structure: /temp/parent/artist.jpg and /temp/parent/artist/album/
+				parentDir := filepath.Join(tempDir, "parent")
+				artistDir := filepath.Join(parentDir, "artist")
+				albumDir := filepath.Join(artistDir, "album")
+				Expect(os.MkdirAll(albumDir, 0755)).To(Succeed())
+
+				// Put artist image in parent directory
+				artistImagePath := filepath.Join(parentDir, "artist.jpg")
+				Expect(os.WriteFile(artistImagePath, []byte("parent image"), 0600)).To(Succeed())
+
+				testFunc = fromArtistFolder(ctx, artistDir, "artist.*")
+			})
+
+			It("finds image in parent directory", func() {
+				reader, path, err := testFunc()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(reader).ToNot(BeNil())
+				Expect(path).To(ContainSubstring("parent" + string(filepath.Separator) + "artist.jpg"))
+
+				data, err := io.ReadAll(reader)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(string(data)).To(Equal("parent image"))
+				reader.Close()
+			})
+		})
+
+		When("image is two levels up", func() {
+			BeforeEach(func() {
+				// Create test structure: /temp/grandparent/artist.jpg and /temp/grandparent/parent/artist/
+				grandparentDir := filepath.Join(tempDir, "grandparent")
+				parentDir := filepath.Join(grandparentDir, "parent")
+				artistDir := filepath.Join(parentDir, "artist")
+				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
+
+				// Put artist image in grandparent directory
+				artistImagePath := filepath.Join(grandparentDir, "artist.jpg")
+				Expect(os.WriteFile(artistImagePath, []byte("grandparent image"), 0600)).To(Succeed())
+
+				testFunc = fromArtistFolder(ctx, artistDir, "artist.*")
+			})
+
+			It("finds image in grandparent directory", func() {
+				reader, path, err := testFunc()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(reader).ToNot(BeNil())
+				Expect(path).To(ContainSubstring("grandparent" + string(filepath.Separator) + "artist.jpg"))
+
+				data, err := io.ReadAll(reader)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(string(data)).To(Equal("grandparent image"))
+				reader.Close()
+			})
+		})
+
+		When("images exist at multiple levels", func() {
+			BeforeEach(func() {
+				// Create test structure with images at multiple levels
+				grandparentDir := filepath.Join(tempDir, "grandparent")
+				parentDir := filepath.Join(grandparentDir, "parent")
+				artistDir := filepath.Join(parentDir, "artist")
+				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
+
+				// Put artist images at all levels
+				Expect(os.WriteFile(filepath.Join(artistDir, "artist.jpg"), []byte("artist level"), 0600)).To(Succeed())
+				Expect(os.WriteFile(filepath.Join(parentDir, "artist.jpg"), []byte("parent level"), 0600)).To(Succeed())
+				Expect(os.WriteFile(filepath.Join(grandparentDir, "artist.jpg"), []byte("grandparent level"), 0600)).To(Succeed())
+
+				testFunc = fromArtistFolder(ctx, artistDir, "artist.*")
+			})
+
+			It("prioritizes the closest (artist folder) image", func() {
+				reader, path, err := testFunc()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(reader).ToNot(BeNil())
+				Expect(path).To(ContainSubstring("artist" + string(filepath.Separator) + "artist.jpg"))
+
+				data, err := io.ReadAll(reader)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(string(data)).To(Equal("artist level"))
+				reader.Close()
+			})
+		})
+
+		When("pattern matches multiple files", func() {
+			BeforeEach(func() {
+				artistDir := filepath.Join(tempDir, "artist")
+				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
+
+				// Create multiple matching files
+				Expect(os.WriteFile(filepath.Join(artistDir, "artist.abc"), []byte("text file"), 0600)).To(Succeed())
+				Expect(os.WriteFile(filepath.Join(artistDir, "artist.png"), []byte("png image"), 0600)).To(Succeed())
+				Expect(os.WriteFile(filepath.Join(artistDir, "artist.jpg"), []byte("jpg image"), 0600)).To(Succeed())
+
+				testFunc = fromArtistFolder(ctx, artistDir, "artist.*")
+			})
+
+			It("returns the first valid image file in sorted order", func() {
+				reader, path, err := testFunc()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(reader).ToNot(BeNil())
+
+				// Should return an image file,
+				// Files are sorted: jpg comes before png alphabetically.
+				// .abc comes first, but it's not an image.
+				Expect(path).To(ContainSubstring("artist.jpg"))
+				reader.Close()
+			})
+		})
+
+		When("prioritizing files without numeric suffixes", func() {
+			BeforeEach(func() {
+				// Test case for issue #4683: artist.jpg should come before artist.1.jpg
+				artistDir := filepath.Join(tempDir, "artist")
+				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
+
+				// Create multiple matches with and without numeric suffixes
+				Expect(os.WriteFile(filepath.Join(artistDir, "artist.1.jpg"), []byte("artist 1"), 0600)).To(Succeed())
+				Expect(os.WriteFile(filepath.Join(artistDir, "artist.jpg"), []byte("artist main"), 0600)).To(Succeed())
+				Expect(os.WriteFile(filepath.Join(artistDir, "artist.2.jpg"), []byte("artist 2"), 0600)).To(Succeed())
+
+				testFunc = fromArtistFolder(ctx, artistDir, "artist.*")
+			})
+
+			It("returns artist.jpg before artist.1.jpg and artist.2.jpg", func() {
+				reader, path, err := testFunc()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(reader).ToNot(BeNil())
+				Expect(path).To(ContainSubstring("artist.jpg"))
+
+				// Verify it's the main file, not a numbered variant
+				data, err := io.ReadAll(reader)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(string(data)).To(Equal("artist main"))
+				reader.Close()
+			})
+		})
+
+		When("handling case-insensitive sorting", func() {
+			BeforeEach(func() {
+				// Test case to ensure case-insensitive natural sorting
+				artistDir := filepath.Join(tempDir, "artist")
+				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
+
+				// Create files with mixed case names
+				Expect(os.WriteFile(filepath.Join(artistDir, "Folder.jpg"), []byte("folder"), 0600)).To(Succeed())
+				Expect(os.WriteFile(filepath.Join(artistDir, "artist.jpg"), []byte("artist"), 0600)).To(Succeed())
+				Expect(os.WriteFile(filepath.Join(artistDir, "BACK.jpg"), []byte("back"), 0600)).To(Succeed())
+
+				testFunc = fromArtistFolder(ctx, artistDir, "*.*")
+			})
+
+			It("sorts case-insensitively", func() {
+				reader, path, err := testFunc()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(reader).ToNot(BeNil())
+
+				// Should return artist.jpg first (case-insensitive: "artist" < "back" < "folder")
+				Expect(path).To(ContainSubstring("artist.jpg"))
+
+				data, err := io.ReadAll(reader)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(string(data)).To(Equal("artist"))
+				reader.Close()
+			})
+		})
+
+		When("no matching files exist anywhere", func() {
+			BeforeEach(func() {
+				artistDir := filepath.Join(tempDir, "artist")
+				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
+
+				// Create non-matching files
+				Expect(os.WriteFile(filepath.Join(artistDir, "cover.jpg"), []byte("cover image"), 0600)).To(Succeed())
+
+				testFunc = fromArtistFolder(ctx, artistDir, "artist.*")
+			})
+
+			It("returns an error", func() {
+				reader, path, err := testFunc()
+				Expect(err).To(HaveOccurred())
+				Expect(reader).To(BeNil())
+				Expect(path).To(BeEmpty())
+				Expect(err.Error()).To(ContainSubstring("no matches for 'artist.*'"))
+				Expect(err.Error()).To(ContainSubstring("parent directories"))
+			})
+		})
+
+		When("directory traversal reaches filesystem root", func() {
+			BeforeEach(func() {
+				// Start from a shallow directory to test root boundary
+				artistDir := filepath.Join(tempDir, "artist")
+				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
+
+				testFunc = fromArtistFolder(ctx, artistDir, "artist.*")
+			})
+
+			It("handles root boundary gracefully", func() {
+				reader, path, err := testFunc()
+				Expect(err).To(HaveOccurred())
+				Expect(reader).To(BeNil())
+				Expect(path).To(BeEmpty())
+				// Should not panic or cause infinite loop
+			})
+		})
+
+		When("file exists but cannot be opened", func() {
+			BeforeEach(func() {
+				artistDir := filepath.Join(tempDir, "artist")
+				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
+
+				// Create a file that cannot be opened (permission denied)
+				restrictedFile := filepath.Join(artistDir, "artist.jpg")
+				Expect(os.WriteFile(restrictedFile, []byte("restricted"), 0600)).To(Succeed())
+
+				testFunc = fromArtistFolder(ctx, artistDir, "artist.*")
+			})
+
+			It("logs warning and continues searching", func() {
+				// This test depends on the ability to restrict file permissions
+				// For now, we'll just ensure it doesn't panic and returns appropriate error
+				reader, _, err := testFunc()
+				// The file should be readable in test environment, so this will succeed
+				// In a real scenario with permission issues, it would continue searching
+				if err == nil {
+					Expect(reader).ToNot(BeNil())
+					reader.Close()
+				}
+			})
+		})
+
+		When("single album artist scenario (original issue)", func() {
+			BeforeEach(func() {
+				// Simulate the exact folder structure from the issue:
+				// /music/artist/album1/ (single album)
+				// /music/artist/artist.jpg (artist image that should be found)
+				artistDir := filepath.Join(tempDir, "music", "artist")
+				albumDir := filepath.Join(artistDir, "album1")
+				Expect(os.MkdirAll(albumDir, 0755)).To(Succeed())
+
+				// Create artist.jpg in the artist folder (this was not being found before)
+				artistImagePath := filepath.Join(artistDir, "artist.jpg")
+				Expect(os.WriteFile(artistImagePath, []byte("single album artist image"), 0600)).To(Succeed())
+
+				// The fromArtistFolder is called with the artist folder path
+				testFunc = fromArtistFolder(ctx, artistDir, "artist.*")
+			})
+
+			It("finds artist.jpg in artist folder for single album artist", func() {
+				reader, path, err := testFunc()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(reader).ToNot(BeNil())
+				Expect(path).To(ContainSubstring("artist.jpg"))
+				Expect(path).To(ContainSubstring("artist"))
+
+				// Verify the content
+				data, err := io.ReadAll(reader)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(string(data)).To(Equal("single album artist image"))
+				reader.Close()
+			})
+		})
+	})
 })
 
 type fakeFolderRepo struct {

core/artwork/reader_resized.go

@@ -87,6 +87,11 @@ func resizeImage(reader io.Reader, size int, square bool) (io.Reader, int, error
 	bounds := original.Bounds()
 	originalSize := max(bounds.Max.X, bounds.Max.Y)
 
+	// Clamp size to original dimensions - upscaling wastes resources and adds no information
+	if size > originalSize {
+		size = originalSize
+	}
+
 	if originalSize <= size && !square {
 		return nil, originalSize, nil
 	}

core/artwork/sources.go

@@ -16,12 +16,14 @@ import (
 	"time"
 
 	"github.com/dhowden/tag"
+	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/core/external"
 	"github.com/navidrome/navidrome/core/ffmpeg"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/resources"
+	"go.senan.xyz/taglib"
 )
 
 func selectImageReader(ctx context.Context, artID model.ArtworkID, extractFuncs ...sourceFunc) (io.ReadCloser, string, error) {
@@ -84,6 +86,13 @@ var picTypeRegexes = []*regexp.Regexp{
 }
 
 func fromTag(ctx context.Context, path string) sourceFunc {
+	if conf.Server.DevLegacyEmbedImage {
+		return fromTagLegacy(ctx, path)
+	}
+	return fromTagGoTaglib(ctx, path)
+}
+
+func fromTagLegacy(ctx context.Context, path string) sourceFunc {
 	return func() (io.ReadCloser, string, error) {
 		if path == "" {
 			return nil, "", nil
@@ -128,6 +137,44 @@ func fromTag(ctx context.Context, path string) sourceFunc {
 	}
 }
 
+func fromTagGoTaglib(ctx context.Context, path string) sourceFunc {
+	return func() (io.ReadCloser, string, error) {
+		if path == "" {
+			return nil, "", nil
+		}
+		f, err := taglib.OpenReadOnly(path, taglib.WithReadStyle(taglib.ReadStyleFast))
+		if err != nil {
+			return nil, "", err
+		}
+		defer f.Close()
+
+		images := f.Properties().Images
+		if len(images) == 0 {
+			return nil, "", fmt.Errorf("no embedded image found in %s", path)
+		}
+
+		imageIndex := findBestImageIndex(ctx, images, path)
+		data, err := f.Image(imageIndex)
+		if err != nil || len(data) == 0 {
+			return nil, "", fmt.Errorf("could not load embedded image from %s", path)
+		}
+		return io.NopCloser(bytes.NewReader(data)), path, nil
+	}
+}
+
+func findBestImageIndex(ctx context.Context, images []taglib.ImageDesc, path string) int {
+	for _, regex := range picTypeRegexes {
+		for i, img := range images {
+			if regex.MatchString(img.Type) {
+				log.Trace(ctx, "Found embedded image", "type", img.Type, "path", path)
+				return i
+			}
+		}
+	}
+	log.Trace(ctx, "Could not find a front image. Getting the first one", "type", images[0].Type, "path", path)
+	return 0
+}
+
 func fromFFmpegTag(ctx context.Context, ffmpeg ffmpeg.FFmpeg, path string) sourceFunc {
 	return func() (io.ReadCloser, string, error) {
 		if path == "" {
@@ -182,13 +229,14 @@ func fromAlbumExternalSource(ctx context.Context, al model.Album, provider exter
 func fromURL(ctx context.Context, imageUrl *url.URL) (io.ReadCloser, string, error) {
 	hc := http.Client{Timeout: 5 * time.Second}
 	req, _ := http.NewRequestWithContext(ctx, http.MethodGet, imageUrl.String(), nil)
+	req.Header.Set("User-Agent", consts.HTTPUserAgent)
 	resp, err := hc.Do(req)
 	if err != nil {
 		return nil, "", err
 	}
 	if resp.StatusCode != http.StatusOK {
 		resp.Body.Close()
-		return nil, "", fmt.Errorf("error retrieveing artwork from %s: %s", imageUrl, resp.Status)
+		return nil, "", fmt.Errorf("error retrieving artwork from %s: %s", imageUrl, resp.Status)
 	}
 	return resp.Body, imageUrl.String(), nil
 }

core/auth/auth.go

@@ -113,9 +113,9 @@ func WithAdminUser(ctx context.Context, ds model.DataStore) context.Context {
 	if err != nil {
 		c, err := ds.User(ctx).CountAll()
 		if c == 0 && err == nil {
-			log.Debug(ctx, "Scanner: No admin user yet!", err)
+			log.Debug(ctx, "No admin user yet!", err)
 		} else {
-			log.Error(ctx, "Scanner: No admin user found!", err)
+			log.Error(ctx, "No admin user found!", err)
 		}
 		u = &model.User{}
 	}

core/external/extdata_helper_test.go

@@ -92,6 +92,11 @@ func (m *mockMediaFileRepo) Get(id string) (*model.MediaFile, error) {
 	return args.Get(0).(*model.MediaFile), args.Error(1)
 }
 
+// GetAllByTags implements model.MediaFileRepository.
+func (m *mockMediaFileRepo) GetAllByTags(_ model.TagName, _ []string, options ...model.QueryOptions) (model.MediaFiles, error) {
+	return m.GetAll(options...)
+}
+
 // GetAll implements model.MediaFileRepository.
 func (m *mockMediaFileRepo) GetAll(options ...model.QueryOptions) (model.MediaFiles, error) {
 	argsSlice := make([]interface{}, len(options))
@@ -190,10 +195,13 @@ type mockAgents struct {
 	topSongsAgent  agents.ArtistTopSongsRetriever
 	similarAgent   agents.ArtistSimilarRetriever
 	imageAgent     agents.ArtistImageRetriever
-	albumInfoAgent agents.AlbumInfoRetriever
-	bioAgent       agents.ArtistBiographyRetriever
-	mbidAgent      agents.ArtistMBIDRetriever
-	urlAgent       agents.ArtistURLRetriever
+	albumInfoAgent interface {
+		agents.AlbumInfoRetriever
+		agents.AlbumImageRetriever
+	}
+	bioAgent  agents.ArtistBiographyRetriever
+	mbidAgent agents.ArtistMBIDRetriever
+	urlAgent  agents.ArtistURLRetriever
 	agents.Interface
 }
 
@@ -268,3 +276,38 @@ func (m *mockAgents) GetArtistImages(ctx context.Context, id, name, mbid string)
 	}
 	return nil, args.Error(1)
 }
+
+func (m *mockAgents) GetAlbumImages(ctx context.Context, name, artist, mbid string) ([]agents.ExternalImage, error) {
+	if m.albumInfoAgent != nil {
+		return m.albumInfoAgent.GetAlbumImages(ctx, name, artist, mbid)
+	}
+	args := m.Called(ctx, name, artist, mbid)
+	if args.Get(0) != nil {
+		return args.Get(0).([]agents.ExternalImage), args.Error(1)
+	}
+	return nil, args.Error(1)
+}
+
+func (m *mockAgents) GetSimilarSongsByTrack(ctx context.Context, id, name, artist, mbid string, count int) ([]agents.Song, error) {
+	args := m.Called(ctx, id, name, artist, mbid, count)
+	if args.Get(0) != nil {
+		return args.Get(0).([]agents.Song), args.Error(1)
+	}
+	return nil, args.Error(1)
+}
+
+func (m *mockAgents) GetSimilarSongsByAlbum(ctx context.Context, id, name, artist, mbid string, count int) ([]agents.Song, error) {
+	args := m.Called(ctx, id, name, artist, mbid, count)
+	if args.Get(0) != nil {
+		return args.Get(0).([]agents.Song), args.Error(1)
+	}
+	return nil, args.Error(1)
+}
+
+func (m *mockAgents) GetSimilarSongsByArtist(ctx context.Context, id, name, mbid string, count int) ([]agents.Song, error) {
+	args := m.Called(ctx, id, name, mbid, count)
+	if args.Get(0) != nil {
+		return args.Get(0).([]agents.Song), args.Error(1)
+	}
+	return nil, args.Error(1)
+}

core/external/provider.go

@@ -3,6 +3,7 @@ package external
 import (
 	"context"
 	"errors"
+	"fmt"
 	"net/url"
 	"sort"
 	"strings"
@@ -11,9 +12,6 @@ import (
 	"github.com/Masterminds/squirrel"
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/core/agents"
-	_ "github.com/navidrome/navidrome/core/agents/lastfm"
-	_ "github.com/navidrome/navidrome/core/agents/listenbrainz"
-	_ "github.com/navidrome/navidrome/core/agents/spotify"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/utils"
@@ -49,22 +47,42 @@ type provider struct {
 
 type auxAlbum struct {
 	model.Album
-	Name string
+}
+
+// Name returns the appropriate album name for external API calls
+// based on the DevPreserveUnicodeInExternalCalls configuration option
+func (a *auxAlbum) Name() string {
+	if conf.Server.DevPreserveUnicodeInExternalCalls {
+		return a.Album.Name
+	}
+	return str.Clear(a.Album.Name)
 }
 
 type auxArtist struct {
 	model.Artist
-	Name string
+}
+
+// Name returns the appropriate artist name for external API calls
+// based on the DevPreserveUnicodeInExternalCalls configuration option
+func (a *auxArtist) Name() string {
+	if conf.Server.DevPreserveUnicodeInExternalCalls {
+		return a.Artist.Name
+	}
+	return str.Clear(a.Artist.Name)
 }
 
 type Agents interface {
 	agents.AlbumInfoRetriever
+	agents.AlbumImageRetriever
 	agents.ArtistBiographyRetriever
 	agents.ArtistMBIDRetriever
 	agents.ArtistImageRetriever
 	agents.ArtistSimilarRetriever
 	agents.ArtistTopSongsRetriever
 	agents.ArtistURLRetriever
+	agents.SimilarSongsByTrackRetriever
+	agents.SimilarSongsByAlbumRetriever
+	agents.SimilarSongsByArtistRetriever
 }
 
 func NewProvider(ds model.DataStore, agents Agents) Provider {
@@ -85,7 +103,6 @@ func (e *provider) getAlbum(ctx context.Context, id string) (auxAlbum, error) {
 	switch v := entity.(type) {
 	case *model.Album:
 		album.Album = *v
-		album.Name = str.Clear(v.Name)
 	case *model.MediaFile:
 		return e.getAlbum(ctx, v.AlbumID)
 	default:
@@ -103,8 +120,9 @@ func (e *provider) UpdateAlbumInfo(ctx context.Context, id string) (*model.Album
 	}
 
 	updatedAt := V(album.ExternalInfoUpdatedAt)
+	albumName := album.Name()
 	if updatedAt.IsZero() {
-		log.Debug(ctx, "AlbumInfo not cached. Retrieving it now", "updatedAt", updatedAt, "id", id, "name", album.Name)
+		log.Debug(ctx, "AlbumInfo not cached. Retrieving it now", "updatedAt", updatedAt, "id", id, "name", albumName)
 		album, err = e.populateAlbumInfo(ctx, album)
 		if err != nil {
 			return nil, err
@@ -113,7 +131,7 @@ func (e *provider) UpdateAlbumInfo(ctx context.Context, id string) (*model.Album
 
 	// If info is expired, trigger a populateAlbumInfo in the background
 	if time.Since(updatedAt) > conf.Server.DevAlbumInfoTimeToLive {
-		log.Debug("Found expired cached AlbumInfo, refreshing in the background", "updatedAt", album.ExternalInfoUpdatedAt, "name", album.Name)
+		log.Debug("Found expired cached AlbumInfo, refreshing in the background", "updatedAt", album.ExternalInfoUpdatedAt, "name", albumName)
 		e.albumQueue.enqueue(&album)
 	}
 
@@ -122,12 +140,13 @@ func (e *provider) UpdateAlbumInfo(ctx context.Context, id string) (*model.Album
 
 func (e *provider) populateAlbumInfo(ctx context.Context, album auxAlbum) (auxAlbum, error) {
 	start := time.Now()
-	info, err := e.ag.GetAlbumInfo(ctx, album.Name, album.AlbumArtist, album.MbzAlbumID)
+	albumName := album.Name()
+	info, err := e.ag.GetAlbumInfo(ctx, albumName, album.AlbumArtist, album.MbzAlbumID)
 	if errors.Is(err, agents.ErrNotFound) {
 		return album, nil
 	}
 	if err != nil {
-		log.Error("Error refreshing AlbumInfo", "id", album.ID, "name", album.Name, "artist", album.AlbumArtist,
+		log.Error("Error refreshing AlbumInfo", "id", album.ID, "name", albumName, "artist", album.AlbumArtist,
 			"elapsed", time.Since(start), err)
 		return album, err
 	}
@@ -139,25 +158,26 @@ func (e *provider) populateAlbumInfo(ctx context.Context, album auxAlbum) (auxAl
 		album.Description = info.Description
 	}
 
-	if len(info.Images) > 0 {
-		sort.Slice(info.Images, func(i, j int) bool {
-			return info.Images[i].Size > info.Images[j].Size
+	images, err := e.ag.GetAlbumImages(ctx, albumName, album.AlbumArtist, album.MbzAlbumID)
+	if err == nil && len(images) > 0 {
+		sort.Slice(images, func(i, j int) bool {
+			return images[i].Size > images[j].Size
 		})
 
-		album.LargeImageUrl = info.Images[0].URL
+		album.LargeImageUrl = images[0].URL
 
-		if len(info.Images) >= 2 {
-			album.MediumImageUrl = info.Images[1].URL
+		if len(images) >= 2 {
+			album.MediumImageUrl = images[1].URL
 		}
 
-		if len(info.Images) >= 3 {
-			album.SmallImageUrl = info.Images[2].URL
+		if len(images) >= 3 {
+			album.SmallImageUrl = images[2].URL
 		}
 	}
 
 	err = e.ds.Album(ctx).UpdateExternalInfo(&album.Album)
 	if err != nil {
-		log.Error(ctx, "Error trying to update album external information", "id", album.ID, "name", album.Name,
+		log.Error(ctx, "Error trying to update album external information", "id", album.ID, "name", albumName,
 			"elapsed", time.Since(start), err)
 	} else {
 		log.Trace(ctx, "AlbumInfo collected", "album", album, "elapsed", time.Since(start))
@@ -177,7 +197,6 @@ func (e *provider) getArtist(ctx context.Context, id string) (auxArtist, error)
 	switch v := entity.(type) {
 	case *model.Artist:
 		artist.Artist = *v
-		artist.Name = str.Clear(v.Name)
 	case *model.MediaFile:
 		return e.getArtist(ctx, v.ArtistID)
 	case *model.Album:
@@ -206,8 +225,9 @@ func (e *provider) refreshArtistInfo(ctx context.Context, id string) (auxArtist,
 
 	// If we don't have any info, retrieves it now
 	updatedAt := V(artist.ExternalInfoUpdatedAt)
+	artistName := artist.Name()
 	if updatedAt.IsZero() {
-		log.Debug(ctx, "ArtistInfo not cached. Retrieving it now", "updatedAt", updatedAt, "id", id, "name", artist.Name)
+		log.Debug(ctx, "ArtistInfo not cached. Retrieving it now", "updatedAt", updatedAt, "id", id, "name", artistName)
 		artist, err = e.populateArtistInfo(ctx, artist)
 		if err != nil {
 			return auxArtist{}, err
@@ -216,7 +236,7 @@ func (e *provider) refreshArtistInfo(ctx context.Context, id string) (auxArtist,
 
 	// If info is expired, trigger a populateArtistInfo in the background
 	if time.Since(updatedAt) > conf.Server.DevArtistInfoTimeToLive {
-		log.Debug("Found expired cached ArtistInfo, refreshing in the background", "updatedAt", updatedAt, "name", artist.Name)
+		log.Debug("Found expired cached ArtistInfo, refreshing in the background", "updatedAt", updatedAt, "name", artistName)
 		e.artistQueue.enqueue(&artist)
 	}
 	return artist, nil
@@ -225,8 +245,9 @@ func (e *provider) refreshArtistInfo(ctx context.Context, id string) (auxArtist,
 func (e *provider) populateArtistInfo(ctx context.Context, artist auxArtist) (auxArtist, error) {
 	start := time.Now()
 	// Get MBID first, if it is not yet available
+	artistName := artist.Name()
 	if artist.MbzArtistID == "" {
-		mbid, err := e.ag.GetArtistMBID(ctx, artist.ID, artist.Name)
+		mbid, err := e.ag.GetArtistMBID(ctx, artist.ID, artistName)
 		if mbid != "" && err == nil {
 			artist.MbzArtistID = mbid
 		}
@@ -238,18 +259,18 @@ func (e *provider) populateArtistInfo(ctx context.Context, artist auxArtist) (au
 	g.Go(func() error { e.callGetImage(ctx, e.ag, &artist); return nil })
 	g.Go(func() error { e.callGetBiography(ctx, e.ag, &artist); return nil })
 	g.Go(func() error { e.callGetURL(ctx, e.ag, &artist); return nil })
-	g.Go(func() error { e.callGetSimilar(ctx, e.ag, &artist, maxSimilarArtists, true); return nil })
+	g.Go(func() error { e.callGetSimilarArtists(ctx, e.ag, &artist, maxSimilarArtists, true); return nil })
 	_ = g.Wait()
 
 	if utils.IsCtxDone(ctx) {
-		log.Warn(ctx, "ArtistInfo update canceled", "elapsed", "id", artist.ID, "name", artist.Name, time.Since(start), ctx.Err())
+		log.Warn(ctx, "ArtistInfo update canceled", "id", artist.ID, "name", artistName, "elapsed", time.Since(start), ctx.Err())
 		return artist, ctx.Err()
 	}
 
 	artist.ExternalInfoUpdatedAt = P(time.Now())
 	err := e.ds.Artist(ctx).UpdateExternalInfo(&artist.Artist)
 	if err != nil {
-		log.Error(ctx, "Error trying to update artist external information", "id", artist.ID, "name", artist.Name,
+		log.Error(ctx, "Error trying to update artist external information", "id", artist.ID, "name", artistName,
 			"elapsed", time.Since(start), err)
 	} else {
 		log.Trace(ctx, "ArtistInfo collected", "artist", artist, "elapsed", time.Since(start))
@@ -258,12 +279,44 @@ func (e *provider) populateArtistInfo(ctx context.Context, artist auxArtist) (au
 }
 
 func (e *provider) SimilarSongs(ctx context.Context, id string, count int) (model.MediaFiles, error) {
+	entity, err := model.GetEntityByID(ctx, e.ds, id)
+	if err != nil {
+		return nil, err
+	}
+
+	var songs []agents.Song
+
+	// Try entity-specific similarity first
+	switch v := entity.(type) {
+	case *model.MediaFile:
+		songs, err = e.ag.GetSimilarSongsByTrack(ctx, v.ID, v.Title, v.Artist, v.MbzRecordingID, count)
+	case *model.Album:
+		songs, err = e.ag.GetSimilarSongsByAlbum(ctx, v.ID, v.Name, v.AlbumArtist, v.MbzAlbumID, count)
+	case *model.Artist:
+		songs, err = e.ag.GetSimilarSongsByArtist(ctx, v.ID, v.Name, v.MbzArtistID, count)
+	default:
+		log.Warn(ctx, "Unknown entity type", "id", id, "type", fmt.Sprintf("%T", entity))
+		return nil, model.ErrNotFound
+	}
+
+	if err == nil && len(songs) > 0 {
+		return e.matchSongsToLibrary(ctx, songs, count)
+	}
+
+	// Fallback to existing similar artists + top songs algorithm
+	return e.similarSongsFallback(ctx, id, count)
+}
+
+// similarSongsFallback uses the original similar artists + top songs algorithm. The idea is to
+// get the artist of the given entity, retrieve similar artists, get their top songs, and pick
+// a weighted random selection of songs to return as similar songs.
+func (e *provider) similarSongsFallback(ctx context.Context, id string, count int) (model.MediaFiles, error) {
 	artist, err := e.getArtist(ctx, id)
 	if err != nil {
 		return nil, err
 	}
 
-	e.callGetSimilar(ctx, e.ag, &artist, 15, false)
+	e.callGetSimilarArtists(ctx, e.ag, &artist, 15, false)
 	if utils.IsCtxDone(ctx) {
 		log.Warn(ctx, "SimilarSongs call canceled", ctx.Err())
 		return nil, ctx.Err()
@@ -277,7 +330,7 @@ func (e *provider) SimilarSongs(ctx context.Context, id string, count int) (mode
 		}
 
 		topCount := max(count, 20)
-		topSongs, err := e.getMatchingTopSongs(ctx, e.ag, &auxArtist{Name: a.Name, Artist: a}, topCount)
+		topSongs, err := e.getMatchingTopSongs(ctx, e.ag, &auxArtist{Artist: a}, topCount)
 		if err != nil {
 			log.Warn(ctx, "Error getting artist's top songs", "artist", a.Name, err)
 			return nil
@@ -340,29 +393,29 @@ func (e *provider) AlbumImage(ctx context.Context, id string) (*url.URL, error)
 		return nil, err
 	}
 
-	info, err := e.ag.GetAlbumInfo(ctx, album.Name, album.AlbumArtist, album.MbzAlbumID)
+	albumName := album.Name()
+	images, err := e.ag.GetAlbumImages(ctx, albumName, album.AlbumArtist, album.MbzAlbumID)
 	if err != nil {
 		switch {
 		case errors.Is(err, agents.ErrNotFound):
-			log.Trace(ctx, "Album not found in agent", "albumID", id, "name", album.Name, "artist", album.AlbumArtist)
+			log.Trace(ctx, "Album not found in agent", "albumID", id, "name", albumName, "artist", album.AlbumArtist)
 			return nil, model.ErrNotFound
 		case errors.Is(err, context.Canceled):
-			log.Debug(ctx, "GetAlbumInfo call canceled", err)
+			log.Debug(ctx, "GetAlbumImages call canceled", err)
 		default:
-			log.Warn(ctx, "Error getting album info from agent", "albumID", id, "name", album.Name, "artist", album.AlbumArtist, err)
+			log.Warn(ctx, "Error getting album images from agent", "albumID", id, "name", albumName, "artist", album.AlbumArtist, err)
 		}
-
 		return nil, err
 	}
 
-	if info == nil {
-		log.Warn(ctx, "Agent returned nil info without error", "albumID", id, "name", album.Name, "artist", album.AlbumArtist)
+	if len(images) == 0 {
+		log.Warn(ctx, "Agent returned no images without error", "albumID", id, "name", albumName, "artist", album.AlbumArtist)
 		return nil, model.ErrNotFound
 	}
 
 	// Return the biggest image
 	var img agents.ExternalImage
-	for _, i := range info.Images {
+	for _, i := range images {
 		if img.Size <= i.Size {
 			img = i
 		}
@@ -398,64 +451,38 @@ func (e *provider) TopSongs(ctx context.Context, artistName string, count int) (
 }
 
 func (e *provider) getMatchingTopSongs(ctx context.Context, agent agents.ArtistTopSongsRetriever, artist *auxArtist, count int) (model.MediaFiles, error) {
-	songs, err := agent.GetArtistTopSongs(ctx, artist.ID, artist.Name, artist.MbzArtistID, count)
+	artistName := artist.Name()
+	songs, err := agent.GetArtistTopSongs(ctx, artist.ID, artistName, artist.MbzArtistID, count)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get top songs for artist %s: %w", artistName, err)
+	}
+
+	// Enrich songs with artist info if not already present (for top songs, we know the artist)
+	for i := range songs {
+		if songs[i].Artist == "" {
+			songs[i].Artist = artistName
+		}
+		if songs[i].ArtistMBID == "" {
+			songs[i].ArtistMBID = artist.MbzArtistID
+		}
+	}
+
+	mfs, err := e.matchSongsToLibrary(ctx, songs, count)
 	if err != nil {
 		return nil, err
 	}
 
-	var mfs model.MediaFiles
-	for _, t := range songs {
-		mf, err := e.findMatchingTrack(ctx, t.MBID, artist.ID, t.Name)
-		if err != nil {
-			continue
-		}
-		mfs = append(mfs, *mf)
-		if len(mfs) == count {
-			break
-		}
-	}
 	if len(mfs) == 0 {
-		log.Debug(ctx, "No matching top songs found", "name", artist.Name)
+		log.Debug(ctx, "No matching top songs found", "name", artistName)
 	} else {
-		log.Debug(ctx, "Found matching top songs", "name", artist.Name, "numSongs", len(mfs))
+		log.Debug(ctx, "Found matching top songs", "name", artistName, "numSongs", len(mfs))
 	}
 
 	return mfs, nil
 }
 
-func (e *provider) findMatchingTrack(ctx context.Context, mbid string, artistID, title string) (*model.MediaFile, error) {
-	if mbid != "" {
-		mfs, err := e.ds.MediaFile(ctx).GetAll(model.QueryOptions{
-			Filters: squirrel.And{
-				squirrel.Eq{"mbz_recording_id": mbid},
-				squirrel.Eq{"missing": false},
-			},
-		})
-		if err == nil && len(mfs) > 0 {
-			return &mfs[0], nil
-		}
-		return e.findMatchingTrack(ctx, "", artistID, title)
-	}
-	mfs, err := e.ds.MediaFile(ctx).GetAll(model.QueryOptions{
-		Filters: squirrel.And{
-			squirrel.Or{
-				squirrel.Eq{"artist_id": artistID},
-				squirrel.Eq{"album_artist_id": artistID},
-			},
-			squirrel.Like{"order_title": str.SanitizeFieldForSorting(title)},
-			squirrel.Eq{"missing": false},
-		},
-		Sort: "starred desc, rating desc, year asc, compilation asc ",
-		Max:  1,
-	})
-	if err != nil || len(mfs) == 0 {
-		return nil, model.ErrNotFound
-	}
-	return &mfs[0], nil
-}
-
 func (e *provider) callGetURL(ctx context.Context, agent agents.ArtistURLRetriever, artist *auxArtist) {
-	artisURL, err := agent.GetArtistURL(ctx, artist.ID, artist.Name, artist.MbzArtistID)
+	artisURL, err := agent.GetArtistURL(ctx, artist.ID, artist.Name(), artist.MbzArtistID)
 	if err != nil {
 		return
 	}
@@ -463,7 +490,7 @@ func (e *provider) callGetURL(ctx context.Context, agent agents.ArtistURLRetriev
 }
 
 func (e *provider) callGetBiography(ctx context.Context, agent agents.ArtistBiographyRetriever, artist *auxArtist) {
-	bio, err := agent.GetArtistBiography(ctx, artist.ID, str.Clear(artist.Name), artist.MbzArtistID)
+	bio, err := agent.GetArtistBiography(ctx, artist.ID, artist.Name(), artist.MbzArtistID)
 	if err != nil {
 		return
 	}
@@ -473,7 +500,7 @@ func (e *provider) callGetBiography(ctx context.Context, agent agents.ArtistBiog
 }
 
 func (e *provider) callGetImage(ctx context.Context, agent agents.ArtistImageRetriever, artist *auxArtist) {
-	images, err := agent.GetArtistImages(ctx, artist.ID, artist.Name, artist.MbzArtistID)
+	images, err := agent.GetArtistImages(ctx, artist.ID, artist.Name(), artist.MbzArtistID)
 	if err != nil {
 		return
 	}
@@ -490,65 +517,182 @@ func (e *provider) callGetImage(ctx context.Context, agent agents.ArtistImageRet
 	}
 }
 
-func (e *provider) callGetSimilar(ctx context.Context, agent agents.ArtistSimilarRetriever, artist *auxArtist,
+func (e *provider) callGetSimilarArtists(ctx context.Context, agent agents.ArtistSimilarRetriever, artist *auxArtist,
 	limit int, includeNotPresent bool) {
-	similar, err := agent.GetSimilarArtists(ctx, artist.ID, artist.Name, artist.MbzArtistID, limit)
+	artistName := artist.Name()
+	similar, err := agent.GetSimilarArtists(ctx, artist.ID, artistName, artist.MbzArtistID, limit)
 	if len(similar) == 0 || err != nil {
 		return
 	}
 	start := time.Now()
-	sa, err := e.mapSimilarArtists(ctx, similar, includeNotPresent)
-	log.Debug(ctx, "Mapped Similar Artists", "artist", artist.Name, "numSimilar", len(sa), "elapsed", time.Since(start))
+	sa, err := e.mapSimilarArtists(ctx, similar, limit, includeNotPresent)
+	log.Debug(ctx, "Mapped Similar Artists", "artist", artistName, "numSimilar", len(sa), "elapsed", time.Since(start))
 	if err != nil {
 		return
 	}
 	artist.SimilarArtists = sa
 }
 
-func (e *provider) mapSimilarArtists(ctx context.Context, similar []agents.Artist, includeNotPresent bool) (model.Artists, error) {
+func (e *provider) mapSimilarArtists(ctx context.Context, similar []agents.Artist, limit int, includeNotPresent bool) (model.Artists, error) {
 	var result model.Artists
 	var notPresent []string
 
-	artistNames := slice.Map(similar, func(artist agents.Artist) string { return artist.Name })
-
-	// Query all artists at once
-	clauses := slice.Map(artistNames, func(name string) squirrel.Sqlizer {
-		return squirrel.Like{"artist.name": name}
-	})
-	artists, err := e.ds.Artist(ctx).GetAll(model.QueryOptions{
-		Filters: squirrel.Or(clauses),
-	})
+	// Load artists by ID (highest priority)
+	idMatches, err := e.loadArtistsByID(ctx, similar)
 	if err != nil {
 		return nil, err
 	}
 
-	// Create a map for quick lookup
-	artistMap := make(map[string]model.Artist)
-	for _, artist := range artists {
-		artistMap[artist.Name] = artist
+	// Load artists by MBID (second priority)
+	mbidMatches, err := e.loadArtistsByMBID(ctx, similar, idMatches)
+	if err != nil {
+		return nil, err
 	}
 
-	// Process the similar artists
+	// Load artists by name (lowest priority, fallback)
+	nameMatches, err := e.loadArtistsByName(ctx, similar, idMatches, mbidMatches)
+	if err != nil {
+		return nil, err
+	}
+
+	count := 0
+
+	// Process the similar artists using priority: ID → MBID → Name
 	for _, s := range similar {
-		if artist, found := artistMap[s.Name]; found {
+		if count >= limit {
+			break
+		}
+		// Try ID match first
+		if s.ID != "" {
+			if artist, found := idMatches[s.ID]; found {
+				result = append(result, artist)
+				count++
+				continue
+			}
+		}
+		// Try MBID match second
+		if s.MBID != "" {
+			if artist, found := mbidMatches[s.MBID]; found {
+				result = append(result, artist)
+				count++
+				continue
+			}
+		}
+		// Fall back to name match
+		if artist, found := nameMatches[s.Name]; found {
 			result = append(result, artist)
+			count++
 		} else {
 			notPresent = append(notPresent, s.Name)
 		}
 	}
 
 	// Then fill up with non-present artists
-	if includeNotPresent {
+	if includeNotPresent && count < limit {
 		for _, s := range notPresent {
 			// Let the ID empty to indicate that the artist is not present in the DB
 			sa := model.Artist{Name: s}
 			result = append(result, sa)
+
+			count++
+			if count >= limit {
+				break
+			}
 		}
 	}
 
 	return result, nil
 }
 
+func (e *provider) loadArtistsByID(ctx context.Context, similar []agents.Artist) (map[string]model.Artist, error) {
+	var ids []string
+	for _, s := range similar {
+		if s.ID != "" {
+			ids = append(ids, s.ID)
+		}
+	}
+	matches := map[string]model.Artist{}
+	if len(ids) == 0 {
+		return matches, nil
+	}
+	res, err := e.ds.Artist(ctx).GetAll(model.QueryOptions{
+		Filters: squirrel.Eq{"artist.id": ids},
+	})
+	if err != nil {
+		return matches, err
+	}
+	for _, a := range res {
+		if _, ok := matches[a.ID]; !ok {
+			matches[a.ID] = a
+		}
+	}
+	return matches, nil
+}
+
+func (e *provider) loadArtistsByMBID(ctx context.Context, similar []agents.Artist, idMatches map[string]model.Artist) (map[string]model.Artist, error) {
+	var mbids []string
+	for _, s := range similar {
+		// Skip if already matched by ID
+		if s.ID != "" && idMatches[s.ID].ID != "" {
+			continue
+		}
+		if s.MBID != "" {
+			mbids = append(mbids, s.MBID)
+		}
+	}
+	matches := map[string]model.Artist{}
+	if len(mbids) == 0 {
+		return matches, nil
+	}
+	res, err := e.ds.Artist(ctx).GetAll(model.QueryOptions{
+		Filters: squirrel.Eq{"mbz_artist_id": mbids},
+	})
+	if err != nil {
+		return matches, err
+	}
+	for _, a := range res {
+		if id := a.MbzArtistID; id != "" {
+			if _, ok := matches[id]; !ok {
+				matches[id] = a
+			}
+		}
+	}
+	return matches, nil
+}
+
+func (e *provider) loadArtistsByName(ctx context.Context, similar []agents.Artist, idMatches map[string]model.Artist, mbidMatches map[string]model.Artist) (map[string]model.Artist, error) {
+	var names []string
+	for _, s := range similar {
+		// Skip if already matched by ID or MBID
+		if s.ID != "" && idMatches[s.ID].ID != "" {
+			continue
+		}
+		if s.MBID != "" && mbidMatches[s.MBID].ID != "" {
+			continue
+		}
+		names = append(names, s.Name)
+	}
+	matches := map[string]model.Artist{}
+	if len(names) == 0 {
+		return matches, nil
+	}
+	clauses := slice.Map(names, func(name string) squirrel.Sqlizer {
+		return squirrel.Like{"artist.name": name}
+	})
+	res, err := e.ds.Artist(ctx).GetAll(model.QueryOptions{
+		Filters: squirrel.Or(clauses),
+	})
+	if err != nil {
+		return matches, err
+	}
+	for _, a := range res {
+		if _, ok := matches[a.Name]; !ok {
+			matches[a.Name] = a
+		}
+	}
+	return matches, nil
+}
+
 func (e *provider) findArtistByName(ctx context.Context, artistName string) (*auxArtist, error) {
 	artists, err := e.ds.Artist(ctx).GetAll(model.QueryOptions{
 		Filters: squirrel.Like{"artist.name": artistName},
@@ -560,11 +704,7 @@ func (e *provider) findArtistByName(ctx context.Context, artistName string) (*au
 	if len(artists) == 0 {
 		return nil, model.ErrNotFound
 	}
-	artist := &auxArtist{
-		Artist: artists[0],
-		Name:   str.Clear(artists[0].Name),
-	}
-	return artist, nil
+	return &auxArtist{Artist: artists[0]}, nil
 }
 
 func (e *provider) loadSimilar(ctx context.Context, artist *auxArtist, count int, includeNotPresent bool) error {
@@ -580,7 +720,7 @@ func (e *provider) loadSimilar(ctx context.Context, artist *auxArtist, count int
 		Filters: squirrel.Eq{"artist.id": ids},
 	})
 	if err != nil {
-		log.Error("Error loading similar artists", "id", artist.ID, "name", artist.Name, err)
+		log.Error("Error loading similar artists", "id", artist.ID, "name", artist.Name(), err)
 		return err
 	}
 

core/external/provider_albumimage_test.go

@@ -23,7 +23,6 @@ var _ = Describe("Provider - AlbumImage", func() {
 	var mockAlbumRepo *mockAlbumRepo
 	var mockMediaFileRepo *mockMediaFileRepo
 	var mockAlbumAgent *mockAlbumInfoAgent
-	var agentsCombined *mockAgents
 	var ctx context.Context
 
 	BeforeEach(func() {
@@ -43,10 +42,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 
 		mockAlbumAgent = newMockAlbumInfoAgent()
 
-		agentsCombined = &mockAgents{
-			albumInfoAgent: mockAlbumAgent,
-		}
-
+		agentsCombined := &mockAgents{albumInfoAgent: mockAlbumAgent}
 		provider = NewProvider(ds, agentsCombined)
 
 		// Default mocks
@@ -66,13 +62,11 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once() // Expect GetEntityByID sequence
 		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
 		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumInfo", ctx, "Album One", "", "").
-			Return(&agents.AlbumInfo{
-				Images: []agents.ExternalImage{
-					{URL: "http://example.com/large.jpg", Size: 1000},
-					{URL: "http://example.com/medium.jpg", Size: 500},
-					{URL: "http://example.com/small.jpg", Size: 200},
-				},
+		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").
+			Return([]agents.ExternalImage{
+				{URL: "http://example.com/large.jpg", Size: 1000},
+				{URL: "http://example.com/medium.jpg", Size: 500},
+				{URL: "http://example.com/small.jpg", Size: 200},
 			}, nil).Once()
 
 		expectedURL, _ := url.Parse("http://example.com/large.jpg")
@@ -82,8 +76,8 @@ var _ = Describe("Provider - AlbumImage", func() {
 		Expect(imgURL).To(Equal(expectedURL))
 		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1") // From GetEntityByID
 		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockArtistRepo.AssertNotCalled(GinkgoT(), "Get", "artist-1")                     // Artist lookup no longer happens in getAlbum
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumInfo", ctx, "Album One", "", "") // Expect empty artist name
+		mockArtistRepo.AssertNotCalled(GinkgoT(), "Get", "artist-1")                       // Artist lookup no longer happens in getAlbum
+		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "") // Expect empty artist name
 	})
 
 	It("returns ErrNotFound if the album is not found in the DB", func() {
@@ -99,7 +93,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "not-found")
 		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "not-found")
 		mockMediaFileRepo.AssertCalled(GinkgoT(), "Get", "not-found")
-		mockAlbumAgent.AssertNotCalled(GinkgoT(), "GetAlbumInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything)
+		mockAlbumAgent.AssertNotCalled(GinkgoT(), "GetAlbumImages", mock.Anything, mock.Anything, mock.Anything)
 	})
 
 	It("returns the agent error if the agent fails", func() {
@@ -109,7 +103,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 
 		agentErr := errors.New("agent failure")
 		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumInfo", ctx, "Album One", "", "").Return(nil, agentErr).Once() // Expect empty artist
+		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").Return(nil, agentErr).Once() // Expect empty artist
 
 		imgURL, err := provider.AlbumImage(ctx, "album-1")
 
@@ -118,7 +112,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1")
 		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
 		mockArtistRepo.AssertNotCalled(GinkgoT(), "Get", "artist-1")
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumInfo", ctx, "Album One", "", "") // Expect empty artist
+		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "") // Expect empty artist
 	})
 
 	It("returns ErrNotFound if the agent returns ErrNotFound", func() {
@@ -127,7 +121,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
 
 		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumInfo", ctx, "Album One", "", "").Return(nil, agents.ErrNotFound).Once() // Expect empty artist
+		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").Return(nil, agents.ErrNotFound).Once() // Expect empty artist
 
 		imgURL, err := provider.AlbumImage(ctx, "album-1")
 
@@ -135,7 +129,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 		Expect(imgURL).To(BeNil())
 		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1")
 		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumInfo", ctx, "Album One", "", "") // Expect empty artist
+		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "") // Expect empty artist
 	})
 
 	It("returns ErrNotFound if the agent returns no images", func() {
@@ -144,8 +138,8 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
 
 		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumInfo", ctx, "Album One", "", "").
-			Return(&agents.AlbumInfo{Images: []agents.ExternalImage{}}, nil).Once() // Expect empty artist
+		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").
+			Return([]agents.ExternalImage{}, nil).Once() // Expect empty artist
 
 		imgURL, err := provider.AlbumImage(ctx, "album-1")
 
@@ -153,7 +147,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 		Expect(imgURL).To(BeNil())
 		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1")
 		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumInfo", ctx, "Album One", "", "") // Expect empty artist
+		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "") // Expect empty artist
 	})
 
 	It("returns context error if context is canceled", func() {
@@ -163,7 +157,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once()
 		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
 		// Expect the agent call even if context is cancelled, returning the context error
-		mockAlbumAgent.On("GetAlbumInfo", cctx, "Album One", "", "").Return(nil, context.Canceled).Once()
+		mockAlbumAgent.On("GetAlbumImages", cctx, "Album One", "", "").Return(nil, context.Canceled).Once()
 		// Cancel the context *before* calling the function under test
 		cancelCtx()
 
@@ -174,7 +168,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1")
 		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
 		// Agent should now be called, verify this expectation
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumInfo", cctx, "Album One", "", "")
+		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", cctx, "Album One", "", "")
 	})
 
 	It("derives album ID from MediaFile ID", func() {
@@ -186,13 +180,11 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
 
 		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumInfo", ctx, "Album One", "", "").
-			Return(&agents.AlbumInfo{
-				Images: []agents.ExternalImage{
-					{URL: "http://example.com/large.jpg", Size: 1000},
-					{URL: "http://example.com/medium.jpg", Size: 500},
-					{URL: "http://example.com/small.jpg", Size: 200},
-				},
+		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").
+			Return([]agents.ExternalImage{
+				{URL: "http://example.com/large.jpg", Size: 1000},
+				{URL: "http://example.com/medium.jpg", Size: 500},
+				{URL: "http://example.com/small.jpg", Size: 200},
 			}, nil).Once()
 
 		expectedURL, _ := url.Parse("http://example.com/large.jpg")
@@ -206,7 +198,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1")
 		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
 		mockArtistRepo.AssertNotCalled(GinkgoT(), "Get", "artist-1")
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumInfo", ctx, "Album One", "", "")
+		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "")
 	})
 
 	It("handles different image orders from agent", func() {
@@ -214,13 +206,11 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once() // Expect GetEntityByID sequence
 		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
 		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumInfo", ctx, "Album One", "", "").
-			Return(&agents.AlbumInfo{
-				Images: []agents.ExternalImage{
-					{URL: "http://example.com/small.jpg", Size: 200},
-					{URL: "http://example.com/large.jpg", Size: 1000},
-					{URL: "http://example.com/medium.jpg", Size: 500},
-				},
+		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").
+			Return([]agents.ExternalImage{
+				{URL: "http://example.com/small.jpg", Size: 200},
+				{URL: "http://example.com/large.jpg", Size: 1000},
+				{URL: "http://example.com/medium.jpg", Size: 500},
 			}, nil).Once()
 
 		expectedURL, _ := url.Parse("http://example.com/large.jpg")
@@ -228,7 +218,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 
 		Expect(err).ToNot(HaveOccurred())
 		Expect(imgURL).To(Equal(expectedURL)) // Should still pick the largest
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumInfo", ctx, "Album One", "", "")
+		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "")
 	})
 
 	It("handles agent returning only one image", func() {
@@ -236,11 +226,9 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once() // Expect GetEntityByID sequence
 		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
 		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumInfo", ctx, "Album One", "", "").
-			Return(&agents.AlbumInfo{
-				Images: []agents.ExternalImage{
-					{URL: "http://example.com/single.jpg", Size: 700},
-				},
+		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").
+			Return([]agents.ExternalImage{
+				{URL: "http://example.com/single.jpg", Size: 700},
 			}, nil).Once()
 
 		expectedURL, _ := url.Parse("http://example.com/single.jpg")
@@ -248,7 +236,7 @@ var _ = Describe("Provider - AlbumImage", func() {
 
 		Expect(err).ToNot(HaveOccurred())
 		Expect(imgURL).To(Equal(expectedURL))
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumInfo", ctx, "Album One", "", "")
+		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "")
 	})
 
 	It("returns ErrNotFound if deriving album ID fails", func() {
@@ -270,14 +258,78 @@ var _ = Describe("Provider - AlbumImage", func() {
 		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "not-found")
 		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "not-found")
 		mockMediaFileRepo.AssertCalled(GinkgoT(), "Get", "not-found")
-		mockAlbumAgent.AssertNotCalled(GinkgoT(), "GetAlbumInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything)
+		mockAlbumAgent.AssertNotCalled(GinkgoT(), "GetAlbumImages", mock.Anything, mock.Anything, mock.Anything)
+	})
+
+	Context("Unicode handling in album names", func() {
+		var albumWithEnDash *model.Album
+		var expectedURL *url.URL
+
+		const (
+			originalAlbumName   = "Raising Hell–Deluxe" // Album name with en dash
+			normalizedAlbumName = "Raising Hell-Deluxe" // Normalized version with hyphen
+		)
+
+		BeforeEach(func() {
+			// Test with en dash (–) in album name
+			albumWithEnDash = &model.Album{ID: "album-endash", Name: originalAlbumName, AlbumArtistID: "artist-1"}
+			mockArtistRepo.Mock = mock.Mock{} // Reset default expectations
+			mockAlbumRepo.Mock = mock.Mock{}  // Reset default expectations
+			mockArtistRepo.On("Get", "album-endash").Return(nil, model.ErrNotFound).Once()
+			mockAlbumRepo.On("Get", "album-endash").Return(albumWithEnDash, nil).Once()
+
+			expectedURL, _ = url.Parse("http://example.com/album.jpg")
+
+			// Mock the album agent to return an image for the album
+			mockAlbumAgent.On("GetAlbumImages", ctx, mock.AnythingOfType("string"), "", "").
+				Return([]agents.ExternalImage{
+					{URL: "http://example.com/album.jpg", Size: 1000},
+				}, nil).Once()
+		})
+
+		When("DevPreserveUnicodeInExternalCalls is true", func() {
+			BeforeEach(func() {
+				conf.Server.DevPreserveUnicodeInExternalCalls = true
+			})
+
+			It("preserves Unicode characters in album names", func() {
+				// Act
+				imgURL, err := provider.AlbumImage(ctx, "album-endash")
+
+				// Assert
+				Expect(err).ToNot(HaveOccurred())
+				Expect(imgURL).To(Equal(expectedURL))
+				mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-endash")
+				// This is the key assertion: ensure the original Unicode name is used
+				mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, originalAlbumName, "", "")
+			})
+		})
+
+		When("DevPreserveUnicodeInExternalCalls is false", func() {
+			BeforeEach(func() {
+				conf.Server.DevPreserveUnicodeInExternalCalls = false
+			})
+
+			It("normalizes Unicode characters", func() {
+				// Act
+				imgURL, err := provider.AlbumImage(ctx, "album-endash")
+
+				// Assert
+				Expect(err).ToNot(HaveOccurred())
+				Expect(imgURL).To(Equal(expectedURL))
+				mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-endash")
+				// This assertion ensures the normalized name is used (en dash → hyphen)
+				mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, normalizedAlbumName, "", "")
+			})
+		})
 	})
 })
 
 // mockAlbumInfoAgent implementation
 type mockAlbumInfoAgent struct {
 	mock.Mock
-	agents.AlbumInfoRetriever // Embed interface
+	agents.AlbumInfoRetriever
+	agents.AlbumImageRetriever
 }
 
 func newMockAlbumInfoAgent() *mockAlbumInfoAgent {
@@ -299,5 +351,14 @@ func (m *mockAlbumInfoAgent) GetAlbumInfo(ctx context.Context, name, artist, mbi
 	return args.Get(0).(*agents.AlbumInfo), args.Error(1)
 }
 
-// Ensure mockAgent implements the interface
+func (m *mockAlbumInfoAgent) GetAlbumImages(ctx context.Context, name, artist, mbid string) ([]agents.ExternalImage, error) {
+	args := m.Called(ctx, name, artist, mbid)
+	if args.Get(0) == nil {
+		return nil, args.Error(1)
+	}
+	return args.Get(0).([]agents.ExternalImage), args.Error(1)
+}
+
+// Ensure mockAgent implements the interfaces
 var _ agents.AlbumInfoRetriever = (*mockAlbumInfoAgent)(nil)
+var _ agents.AlbumImageRetriever = (*mockAlbumInfoAgent)(nil)

core/external/provider_artistimage_test.go

@@ -265,6 +265,67 @@ var _ = Describe("Provider - ArtistImage", func() {
 		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "artist-1")
 		mockImageAgent.AssertCalled(GinkgoT(), "GetArtistImages", ctx, "artist-1", "Artist One", "")
 	})
+
+	Context("Unicode handling in artist names", func() {
+		var artistWithEnDash *model.Artist
+		var expectedURL *url.URL
+
+		const (
+			originalArtistName   = "Run–D.M.C." // Artist name with en dash
+			normalizedArtistName = "Run-D.M.C." // Normalized version with hyphen
+		)
+
+		BeforeEach(func() {
+			// Test with en dash (–) in artist name like "Run–D.M.C."
+			artistWithEnDash = &model.Artist{ID: "artist-endash", Name: originalArtistName}
+			mockArtistRepo.Mock = mock.Mock{} // Reset default expectations
+			mockArtistRepo.On("Get", "artist-endash").Return(artistWithEnDash, nil).Once()
+
+			expectedURL, _ = url.Parse("http://example.com/rundmc.jpg")
+
+			// Mock the image agent to return an image for the artist
+			mockImageAgent.On("GetArtistImages", ctx, "artist-endash", mock.AnythingOfType("string"), "").
+				Return([]agents.ExternalImage{
+					{URL: "http://example.com/rundmc.jpg", Size: 1000},
+				}, nil).Once()
+
+		})
+
+		When("DevPreserveUnicodeInExternalCalls is true", func() {
+			BeforeEach(func() {
+				conf.Server.DevPreserveUnicodeInExternalCalls = true
+			})
+			It("preserves Unicode characters in artist names", func() {
+				// Act
+				imgURL, err := provider.ArtistImage(ctx, "artist-endash")
+
+				// Assert
+				Expect(err).ToNot(HaveOccurred())
+				Expect(imgURL).To(Equal(expectedURL))
+				mockArtistRepo.AssertCalled(GinkgoT(), "Get", "artist-endash")
+				// This is the key assertion: ensure the original Unicode name is used
+				mockImageAgent.AssertCalled(GinkgoT(), "GetArtistImages", ctx, "artist-endash", originalArtistName, "")
+			})
+		})
+
+		When("DevPreserveUnicodeInExternalCalls is false", func() {
+			BeforeEach(func() {
+				conf.Server.DevPreserveUnicodeInExternalCalls = false
+			})
+
+			It("normalizes Unicode characters", func() {
+				// Act
+				imgURL, err := provider.ArtistImage(ctx, "artist-endash")
+
+				// Assert
+				Expect(err).ToNot(HaveOccurred())
+				Expect(imgURL).To(Equal(expectedURL))
+				mockArtistRepo.AssertCalled(GinkgoT(), "Get", "artist-endash")
+				// This assertion ensures the normalized name is used (en dash → hyphen)
+				mockImageAgent.AssertCalled(GinkgoT(), "GetArtistImages", ctx, "artist-endash", normalizedArtistName, "")
+			})
+		})
+	})
 })
 
 // mockArtistImageAgent implementation using testify/mock

core/external/provider_matching.go

@@ -0,0 +1,504 @@
+package external
+
+import (
+	"context"
+	"fmt"
+	"math"
+
+	"github.com/Masterminds/squirrel"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils/str"
+	"github.com/xrash/smetrics"
+)
+
+// matchSongsToLibrary matches agent song results to local library tracks using a multi-phase
+// matching algorithm that prioritizes accuracy over recall.
+//
+// # Algorithm Overview
+//
+// The algorithm matches songs from external agents (Last.fm, Deezer, etc.) to tracks in the
+// local music library using four matching strategies in priority order:
+//
+//  1. Direct ID match: Songs with an ID field are matched directly to MediaFiles by ID
+//  2. MusicBrainz Recording ID (MBID) match: Songs with MBID are matched to tracks with
+//     matching mbz_recording_id
+//  3. ISRC match: Songs with ISRC are matched to tracks with matching ISRC tag
+//  4. Title+Artist fuzzy match: Remaining songs are matched using fuzzy string comparison
+//     with metadata specificity scoring
+//
+// # Matching Priority
+//
+// When selecting the final result, matches are prioritized in order: ID > MBID > ISRC > Title+Artist.
+// This ensures that more reliable identifiers take precedence over fuzzy text matching.
+//
+// # Fuzzy Matching Details
+//
+// For title+artist matching, the algorithm uses Jaro-Winkler similarity (threshold configurable
+// via SimilarSongsMatchThreshold, default 85%). Matches are ranked by:
+//
+//  1. Title similarity (Jaro-Winkler score, 0.0-1.0)
+//  2. Duration proximity (closer duration = higher score, 1.0 if unknown)
+//  3. Specificity level (0-5, based on metadata precision):
+//     - Level 5: Title + Artist MBID + Album MBID (most specific)
+//     - Level 4: Title + Artist MBID + Album name (fuzzy)
+//     - Level 3: Title + Artist name + Album name (fuzzy)
+//     - Level 2: Title + Artist MBID
+//     - Level 1: Title + Artist name
+//     - Level 0: Title only
+//  4. Album similarity (Jaro-Winkler, as final tiebreaker)
+//
+// # Examples
+//
+// Example 1 - MBID Priority:
+//
+//	Agent returns: {Name: "Paranoid Android", MBID: "abc-123", Artist: "Radiohead"}
+//	Library has: [
+//	  {ID: "t1", Title: "Paranoid Android", MbzRecordingID: "abc-123"},
+//	  {ID: "t2", Title: "Paranoid Android", Artist: "Radiohead"},
+//	]
+//	Result: t1 (MBID match takes priority over title+artist)
+//
+// Example 2 - ISRC Priority:
+//
+//	Agent returns: {Name: "Paranoid Android", ISRC: "GBAYE0000351", Artist: "Radiohead"}
+//	Library has: [
+//	  {ID: "t1", Title: "Paranoid Android", Tags: {isrc: ["GBAYE0000351"]}},
+//	  {ID: "t2", Title: "Paranoid Android", Artist: "Radiohead"},
+//	]
+//	Result: t1 (ISRC match takes priority over title+artist)
+//
+// Example 3 - Specificity Ranking:
+//
+//	Agent returns: {Name: "Enjoy the Silence", Artist: "Depeche Mode", Album: "Violator"}
+//	Library has: [
+//	  {ID: "t1", Title: "Enjoy the Silence", Artist: "Depeche Mode", Album: "101"},           // Level 1
+//	  {ID: "t2", Title: "Enjoy the Silence", Artist: "Depeche Mode", Album: "Violator"},      // Level 3
+//	]
+//	Result: t2 (Level 3 beats Level 1 due to album match)
+//
+// Example 4 - Fuzzy Title Matching:
+//
+//	Agent returns: {Name: "Bohemian Rhapsody", Artist: "Queen"}
+//	Library has: {ID: "t1", Title: "Bohemian Rhapsody - Remastered", Artist: "Queen"}
+//	With threshold=85%: Match succeeds (similarity ~0.87)
+//	With threshold=100%: No match (not exact)
+//
+// # Parameters
+//
+//   - ctx: Context for database operations
+//   - songs: Slice of agent.Song results from external providers
+//   - count: Maximum number of matches to return
+//
+// # Returns
+//
+// Returns up to 'count' MediaFiles from the library that best match the input songs,
+// preserving the original order from the agent. Songs that cannot be matched are skipped.
+func (e *provider) matchSongsToLibrary(ctx context.Context, songs []agents.Song, count int) (model.MediaFiles, error) {
+	idMatches, err := e.loadTracksByID(ctx, songs)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load tracks by ID: %w", err)
+	}
+	mbidMatches, err := e.loadTracksByMBID(ctx, songs, idMatches)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load tracks by MBID: %w", err)
+	}
+	isrcMatches, err := e.loadTracksByISRC(ctx, songs, idMatches, mbidMatches)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load tracks by ISRC: %w", err)
+	}
+	titleMatches, err := e.loadTracksByTitleAndArtist(ctx, songs, idMatches, mbidMatches, isrcMatches)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load tracks by title: %w", err)
+	}
+
+	return e.selectBestMatchingSongs(songs, idMatches, mbidMatches, isrcMatches, titleMatches, count), nil
+}
+
+// songMatchedIn checks if a song has already been matched in any of the provided match maps.
+// It checks the song's ID, MBID, and ISRC fields against the corresponding map keys.
+func songMatchedIn(s agents.Song, priorMatches ...map[string]model.MediaFile) bool {
+	_, found := lookupByIdentifiers(s, priorMatches...)
+	return found
+}
+
+// lookupByIdentifiers searches for a song's identifiers (ID, MBID, ISRC) in the provided maps.
+// Returns the first matching MediaFile found and true, or an empty MediaFile and false if no match.
+func lookupByIdentifiers(s agents.Song, maps ...map[string]model.MediaFile) (model.MediaFile, bool) {
+	keys := []string{s.ID, s.MBID, s.ISRC}
+	for _, m := range maps {
+		for _, key := range keys {
+			if key != "" {
+				if mf, ok := m[key]; ok && mf.ID != "" {
+					return mf, true
+				}
+			}
+		}
+	}
+	return model.MediaFile{}, false
+}
+
+// loadTracksByID fetches MediaFiles from the library using direct ID matching.
+// It extracts all non-empty ID fields from the input songs and performs a single
+// batch query to the database. Returns a map keyed by MediaFile ID for O(1) lookup.
+// Only non-missing files are returned.
+func (e *provider) loadTracksByID(ctx context.Context, songs []agents.Song) (map[string]model.MediaFile, error) {
+	var ids []string
+	for _, s := range songs {
+		if s.ID != "" {
+			ids = append(ids, s.ID)
+		}
+	}
+	matches := map[string]model.MediaFile{}
+	if len(ids) == 0 {
+		return matches, nil
+	}
+	res, err := e.ds.MediaFile(ctx).GetAll(model.QueryOptions{
+		Filters: squirrel.And{
+			squirrel.Eq{"media_file.id": ids},
+			squirrel.Eq{"missing": false},
+		},
+	})
+	if err != nil {
+		return matches, err
+	}
+	for _, mf := range res {
+		if _, ok := matches[mf.ID]; !ok {
+			matches[mf.ID] = mf
+		}
+	}
+	return matches, nil
+}
+
+// loadTracksByMBID fetches MediaFiles from the library using MusicBrainz Recording IDs.
+// It extracts all non-empty MBID fields from the input songs and performs a single
+// batch query against the mbz_recording_id column. Returns a map keyed by MBID for
+// O(1) lookup. Only non-missing files are returned.
+func (e *provider) loadTracksByMBID(ctx context.Context, songs []agents.Song, priorMatches ...map[string]model.MediaFile) (map[string]model.MediaFile, error) {
+	var mbids []string
+	for _, s := range songs {
+		if s.MBID != "" && !songMatchedIn(s, priorMatches...) {
+			mbids = append(mbids, s.MBID)
+		}
+	}
+	matches := map[string]model.MediaFile{}
+	if len(mbids) == 0 {
+		return matches, nil
+	}
+	res, err := e.ds.MediaFile(ctx).GetAll(model.QueryOptions{
+		Filters: squirrel.And{
+			squirrel.Eq{"mbz_recording_id": mbids},
+			squirrel.Eq{"missing": false},
+		},
+	})
+	if err != nil {
+		return matches, err
+	}
+	for _, mf := range res {
+		if id := mf.MbzRecordingID; id != "" {
+			if _, ok := matches[id]; !ok {
+				matches[id] = mf
+			}
+		}
+	}
+	return matches, nil
+}
+
+// loadTracksByISRC fetches MediaFiles from the library using ISRC (International Standard
+// Recording Code) matching. It extracts all non-empty ISRC fields from the input songs and
+// queries the tags JSON column for matching ISRC values. Returns a map keyed by ISRC for
+// O(1) lookup. Only non-missing files are returned.
+func (e *provider) loadTracksByISRC(ctx context.Context, songs []agents.Song, priorMatches ...map[string]model.MediaFile) (map[string]model.MediaFile, error) {
+	var isrcs []string
+	for _, s := range songs {
+		if s.ISRC != "" && !songMatchedIn(s, priorMatches...) {
+			isrcs = append(isrcs, s.ISRC)
+		}
+	}
+	matches := map[string]model.MediaFile{}
+	if len(isrcs) == 0 {
+		return matches, nil
+	}
+	res, err := e.ds.MediaFile(ctx).GetAllByTags(model.TagISRC, isrcs, model.QueryOptions{
+		Filters: squirrel.Eq{"missing": false},
+	})
+	if err != nil {
+		return matches, err
+	}
+	for _, mf := range res {
+		for _, isrc := range mf.Tags.Values(model.TagISRC) {
+			if _, ok := matches[isrc]; !ok {
+				matches[isrc] = mf
+			}
+		}
+	}
+	return matches, nil
+}
+
+// songQuery represents a normalized query for matching a song to library tracks.
+// All string fields are sanitized (lowercased, diacritics removed) for comparison.
+// This struct is used internally by loadTracksByTitleAndArtist to group queries by artist.
+type songQuery struct {
+	title      string // Sanitized song title
+	artist     string // Sanitized artist name (without articles like "The")
+	artistMBID string // MusicBrainz Artist ID (optional, for higher specificity matching)
+	album      string // Sanitized album name (optional, for specificity scoring)
+	albumMBID  string // MusicBrainz Album ID (optional, for highest specificity matching)
+	durationMs uint32 // Duration in milliseconds (0 means unknown, skip duration filtering)
+}
+
+// matchScore combines title/album similarity with metadata specificity for ranking matches
+type matchScore struct {
+	titleSimilarity   float64 // 0.0-1.0 (Jaro-Winkler)
+	durationProximity float64 // 0.0-1.0 (closer duration = higher, 1.0 if unknown)
+	albumSimilarity   float64 // 0.0-1.0 (Jaro-Winkler), used as tiebreaker
+	specificityLevel  int     // 0-5 (higher = more specific metadata match)
+}
+
+// betterThan returns true if this score beats another.
+// Comparison order: title similarity > duration proximity > specificity level > album similarity
+func (s matchScore) betterThan(other matchScore) bool {
+	if s.titleSimilarity != other.titleSimilarity {
+		return s.titleSimilarity > other.titleSimilarity
+	}
+	if s.durationProximity != other.durationProximity {
+		return s.durationProximity > other.durationProximity
+	}
+	if s.specificityLevel != other.specificityLevel {
+		return s.specificityLevel > other.specificityLevel
+	}
+	return s.albumSimilarity > other.albumSimilarity
+}
+
+// computeSpecificityLevel determines how well query metadata matches a track (0-5).
+// Higher values indicate more specific matches (MBIDs > names > title only).
+// Uses fuzzy matching for album names with the same threshold as title matching.
+func computeSpecificityLevel(q songQuery, mf model.MediaFile, albumThreshold float64) int {
+	title := str.SanitizeFieldForSorting(mf.Title)
+	artist := str.SanitizeFieldForSortingNoArticle(mf.Artist)
+	album := str.SanitizeFieldForSorting(mf.Album)
+
+	// Level 5: Title + Artist MBID + Album MBID (most specific)
+	if q.artistMBID != "" && q.albumMBID != "" &&
+		mf.MbzArtistID == q.artistMBID && mf.MbzAlbumID == q.albumMBID {
+		return 5
+	}
+	// Level 4: Title + Artist MBID + Album name (fuzzy)
+	if q.artistMBID != "" && q.album != "" &&
+		mf.MbzArtistID == q.artistMBID && similarityRatio(album, q.album) >= albumThreshold {
+		return 4
+	}
+	// Level 3: Title + Artist name + Album name (fuzzy)
+	if q.artist != "" && q.album != "" &&
+		artist == q.artist && similarityRatio(album, q.album) >= albumThreshold {
+		return 3
+	}
+	// Level 2: Title + Artist MBID
+	if q.artistMBID != "" && mf.MbzArtistID == q.artistMBID {
+		return 2
+	}
+	// Level 1: Title + Artist name
+	if q.artist != "" && artist == q.artist {
+		return 1
+	}
+	// Level 0: Title only match (but for fuzzy, title matched via similarity)
+	// Check if at least the title matches exactly
+	if title == q.title {
+		return 0
+	}
+	return -1 // No exact title match, but could still be a fuzzy match
+}
+
+// loadTracksByTitleAndArtist loads tracks matching by title with optional artist/album filtering.
+// Uses a unified scoring approach that combines title similarity (Jaro-Winkler) with
+// metadata specificity (MBIDs, album names) for both exact and fuzzy matches.
+// Returns a map keyed by "title|artist" for compatibility with selectBestMatchingSongs.
+func (e *provider) loadTracksByTitleAndArtist(ctx context.Context, songs []agents.Song, priorMatches ...map[string]model.MediaFile) (map[string]model.MediaFile, error) {
+	queries := e.buildTitleQueries(songs, priorMatches...)
+	if len(queries) == 0 {
+		return map[string]model.MediaFile{}, nil
+	}
+
+	threshold := float64(conf.Server.SimilarSongsMatchThreshold) / 100.0
+
+	// Group queries by artist for efficient DB access
+	byArtist := map[string][]songQuery{}
+	for _, q := range queries {
+		if q.artist != "" {
+			byArtist[q.artist] = append(byArtist[q.artist], q)
+		}
+	}
+
+	matches := map[string]model.MediaFile{}
+	for artist, artistQueries := range byArtist {
+		// Single DB query per artist - get all their tracks
+		tracks, err := e.ds.MediaFile(ctx).GetAll(model.QueryOptions{
+			Filters: squirrel.And{
+				squirrel.Eq{"order_artist_name": artist},
+				squirrel.Eq{"missing": false},
+			},
+			Sort: "starred desc, rating desc, year asc, compilation asc",
+		})
+		if err != nil {
+			continue
+		}
+
+		// Find best match for each query using unified scoring
+		for _, q := range artistQueries {
+			if mf, found := e.findBestMatch(q, tracks, threshold); found {
+				key := q.title + "|" + q.artist
+				if _, exists := matches[key]; !exists {
+					matches[key] = mf
+				}
+			}
+		}
+	}
+	return matches, nil
+}
+
+// durationProximity returns a score from 0.0 to 1.0 indicating how close
+// the track's duration is to the target. A perfect match returns 1.0, and the
+// score decreases as the difference grows (using 1 / (1 + diff)). Returns 1.0
+// if durationMs is 0 (unknown), so duration does not influence scoring.
+func durationProximity(durationMs uint32, mediaFileDurationSec float32) float64 {
+	if durationMs <= 0 {
+		return 1.0 // Unknown duration — don't penalise
+	}
+	durationSec := float64(durationMs) / 1000.0
+	diff := math.Abs(durationSec - float64(mediaFileDurationSec))
+	return 1.0 / (1.0 + diff)
+}
+
+// findBestMatch finds the best matching track using combined title/album similarity and specificity scoring.
+// A track must meet the threshold for title similarity, then the best match is chosen by:
+// 1. Highest title similarity
+// 2. Duration proximity (closer duration = higher score, 1.0 if unknown)
+// 3. Highest specificity level
+// 4. Highest album similarity (as final tiebreaker)
+func (e *provider) findBestMatch(q songQuery, tracks model.MediaFiles, threshold float64) (model.MediaFile, bool) {
+	var bestMatch model.MediaFile
+	bestScore := matchScore{titleSimilarity: -1}
+	found := false
+
+	for _, mf := range tracks {
+		trackTitle := str.SanitizeFieldForSorting(mf.Title)
+		titleSim := similarityRatio(q.title, trackTitle)
+
+		if titleSim < threshold {
+			continue
+		}
+
+		// Compute album similarity for tiebreaking (0.0 if no album in query)
+		var albumSim float64
+		if q.album != "" {
+			trackAlbum := str.SanitizeFieldForSorting(mf.Album)
+			albumSim = similarityRatio(q.album, trackAlbum)
+		}
+
+		score := matchScore{
+			titleSimilarity:   titleSim,
+			durationProximity: durationProximity(q.durationMs, mf.Duration),
+			albumSimilarity:   albumSim,
+			specificityLevel:  computeSpecificityLevel(q, mf, threshold),
+		}
+
+		if score.betterThan(bestScore) {
+			bestScore = score
+			bestMatch = mf
+			found = true
+		}
+	}
+	return bestMatch, found
+}
+
+// buildTitleQueries converts agent songs into normalized songQuery structs for title+artist matching.
+// It skips songs that have already been matched in prior phases (by ID, MBID, or ISRC) and sanitizes
+// all string fields for consistent comparison (lowercase, diacritics removed, articles stripped from artist names).
+func (e *provider) buildTitleQueries(songs []agents.Song, priorMatches ...map[string]model.MediaFile) []songQuery {
+	var queries []songQuery
+	for _, s := range songs {
+		if songMatchedIn(s, priorMatches...) {
+			continue
+		}
+		queries = append(queries, songQuery{
+			title:      str.SanitizeFieldForSorting(s.Name),
+			artist:     str.SanitizeFieldForSortingNoArticle(s.Artist),
+			artistMBID: s.ArtistMBID,
+			album:      str.SanitizeFieldForSorting(s.Album),
+			albumMBID:  s.AlbumMBID,
+			durationMs: s.Duration,
+		})
+	}
+	return queries
+}
+
+// selectBestMatchingSongs assembles the final result by mapping input songs to their best matching
+// library tracks. It iterates through the input songs in order and selects the first available match
+// using priority order: ID > MBID > ISRC > title+artist.
+//
+// The function also handles deduplication: when multiple different input songs would match the same
+// library track (e.g., "Song (Live)" and "Song (Remastered)" both matching "Song (Live)" in the library),
+// only the first match is kept. However, if the same input song appears multiple times (intentional
+// repetition), duplicates are preserved in the output.
+//
+// Returns up to 'count' MediaFiles, preserving the input order. Songs that cannot be matched are skipped.
+func (e *provider) selectBestMatchingSongs(songs []agents.Song, byID, byMBID, byISRC, byTitleArtist map[string]model.MediaFile, count int) model.MediaFiles {
+	mfs := make(model.MediaFiles, 0, len(songs))
+	// Track MediaFile.ID -> input song that added it, for deduplication
+	addedBy := make(map[string]agents.Song, len(songs))
+
+	for _, t := range songs {
+		if len(mfs) == count {
+			break
+		}
+
+		mf, found := findMatchingTrack(t, byID, byMBID, byISRC, byTitleArtist)
+		if !found {
+			continue
+		}
+
+		// Check for duplicate library track
+		if prevSong, alreadyAdded := addedBy[mf.ID]; alreadyAdded {
+			// Only add duplicate if input songs are identical
+			if t != prevSong {
+				continue // Different input songs → skip mismatch-induced duplicate
+			}
+		} else {
+			addedBy[mf.ID] = t
+		}
+
+		mfs = append(mfs, mf)
+	}
+	return mfs
+}
+
+// findMatchingTrack looks up a song in the match maps using priority order: ID > MBID > ISRC > title+artist.
+// Returns the matched MediaFile and true if found, or an empty MediaFile and false if no match exists.
+func findMatchingTrack(t agents.Song, byID, byMBID, byISRC, byTitleArtist map[string]model.MediaFile) (model.MediaFile, bool) {
+	// Try identifier-based matches first (ID, MBID, ISRC)
+	if mf, found := lookupByIdentifiers(t, byID, byMBID, byISRC); found {
+		return mf, true
+	}
+	// Fall back to title+artist fuzzy match
+	key := str.SanitizeFieldForSorting(t.Name) + "|" + str.SanitizeFieldForSortingNoArticle(t.Artist)
+	if mf, ok := byTitleArtist[key]; ok {
+		return mf, true
+	}
+	return model.MediaFile{}, false
+}
+
+// similarityRatio calculates the similarity between two strings using Jaro-Winkler algorithm.
+// Returns a value between 0.0 (completely different) and 1.0 (identical).
+// Jaro-Winkler is well-suited for matching song titles because it gives higher scores
+// when strings share a common prefix (e.g., "Song Title" vs "Song Title - Remastered").
+func similarityRatio(a, b string) float64 {
+	if a == b {
+		return 1.0
+	}
+	if len(a) == 0 || len(b) == 0 {
+		return 0.0
+	}
+	// JaroWinkler params: boostThreshold=0.7, prefixSize=4
+	return smetrics.JaroWinkler(a, b, 0.7, 4)
+}

core/external/provider_matching_internal_test.go

@@ -0,0 +1,57 @@
+package external
+
+import (
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("similarityRatio", func() {
+	It("returns 1.0 for identical strings", func() {
+		Expect(similarityRatio("hello", "hello")).To(BeNumerically("==", 1.0))
+	})
+
+	It("returns 0.0 for empty strings", func() {
+		Expect(similarityRatio("", "test")).To(BeNumerically("==", 0.0))
+		Expect(similarityRatio("test", "")).To(BeNumerically("==", 0.0))
+	})
+
+	It("returns high similarity for remastered suffix", func() {
+		// Jaro-Winkler gives ~0.92 for this case
+		ratio := similarityRatio("paranoid android", "paranoid android remastered")
+		Expect(ratio).To(BeNumerically(">=", 0.85))
+	})
+
+	It("returns high similarity for suffix additions like (Live)", func() {
+		// Jaro-Winkler gives ~0.96 for this case
+		ratio := similarityRatio("bohemian rhapsody", "bohemian rhapsody live")
+		Expect(ratio).To(BeNumerically(">=", 0.90))
+	})
+
+	It("returns high similarity for 'yesterday' variants (common prefix)", func() {
+		// Jaro-Winkler gives ~0.90 because of common prefix
+		ratio := similarityRatio("yesterday", "yesterday once more")
+		Expect(ratio).To(BeNumerically(">=", 0.85))
+	})
+
+	It("returns low similarity for same suffix", func() {
+		// Jaro-Winkler gives ~0.70 for this case
+		ratio := similarityRatio("postman (live)", "taxman (live)")
+		Expect(ratio).To(BeNumerically("<", 0.85))
+	})
+
+	It("handles unicode characters", func() {
+		ratio := similarityRatio("dont stop believin", "don't stop believin'")
+		Expect(ratio).To(BeNumerically(">=", 0.85))
+	})
+
+	It("returns low similarity for completely different strings", func() {
+		ratio := similarityRatio("abc", "xyz")
+		Expect(ratio).To(BeNumerically("<", 0.5))
+	})
+
+	It("is symmetric", func() {
+		ratio1 := similarityRatio("hello world", "hello")
+		ratio2 := similarityRatio("hello", "hello world")
+		Expect(ratio1).To(Equal(ratio2))
+	})
+})

core/external/provider_matching_test.go

@@ -0,0 +1,762 @@
+package external_test
+
+import (
+	"context"
+
+	"github.com/Masterminds/squirrel"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/core/agents"
+	. "github.com/navidrome/navidrome/core/external"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"github.com/stretchr/testify/mock"
+)
+
+var _ = Describe("Provider - Song Matching", func() {
+	var ds model.DataStore
+	var provider Provider
+	var agentsCombined *mockAgents
+	var artistRepo *mockArtistRepo
+	var mediaFileRepo *mockMediaFileRepo
+	var albumRepo *mockAlbumRepo
+	var ctx context.Context
+
+	BeforeEach(func() {
+		ctx = GinkgoT().Context()
+
+		artistRepo = newMockArtistRepo()
+		mediaFileRepo = newMockMediaFileRepo()
+		albumRepo = newMockAlbumRepo()
+
+		ds = &tests.MockDataStore{
+			MockedArtist:    artistRepo,
+			MockedMediaFile: mediaFileRepo,
+			MockedAlbum:     albumRepo,
+		}
+
+		agentsCombined = &mockAgents{}
+		provider = NewProvider(ds, agentsCombined)
+	})
+
+	// Shared helper for tests that only need artist track queries (no ID/MBID matching)
+	setupSimilarSongsExpectations := func(returnedSongs []agents.Song, artistTracks model.MediaFiles) {
+		agentsCombined.On("GetSimilarSongsByTrack", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).
+			Return(returnedSongs, nil).Once()
+
+		// loadTracksByTitleAndArtist - queries by artist name
+		mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+			and, ok := opt.Filters.(squirrel.And)
+			if !ok || len(and) < 2 {
+				return false
+			}
+			eq, hasEq := and[0].(squirrel.Eq)
+			if !hasEq {
+				return false
+			}
+			_, hasArtist := eq["order_artist_name"]
+			return hasArtist
+		})).Return(artistTracks, nil).Maybe()
+	}
+
+	Describe("matchSongsToLibrary priority matching", func() {
+		var track model.MediaFile
+
+		BeforeEach(func() {
+			DeferCleanup(configtest.SetupConfig())
+			// Disable fuzzy matching for these tests to avoid unexpected GetAll calls
+			conf.Server.SimilarSongsMatchThreshold = 100
+
+			track = model.MediaFile{ID: "track-1", Title: "Test Track", Artist: "Test Artist", MbzRecordingID: ""}
+
+			// Setup for GetEntityByID to return the track
+			artistRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+			albumRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+			mediaFileRepo.On("Get", "track-1").Return(&track, nil).Once()
+		})
+
+		setupExpectations := func(returnedSongs []agents.Song, idMatches, mbidMatches, artistTracks model.MediaFiles) {
+			agentsCombined.On("GetSimilarSongsByTrack", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).
+				Return(returnedSongs, nil).Once()
+
+			// loadTracksByID
+			mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+				_, ok := opt.Filters.(squirrel.Eq)
+				return ok
+			})).Return(idMatches, nil).Once()
+
+			// loadTracksByMBID
+			mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+				and, ok := opt.Filters.(squirrel.And)
+				if !ok || len(and) < 1 {
+					return false
+				}
+				eq, hasEq := and[0].(squirrel.Eq)
+				if !hasEq {
+					return false
+				}
+				_, hasMBID := eq["mbz_recording_id"]
+				return hasMBID
+			})).Return(mbidMatches, nil).Once()
+
+			// loadTracksByTitleAndArtist - now queries by artist name
+			mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+				and, ok := opt.Filters.(squirrel.And)
+				if !ok || len(and) < 2 {
+					return false
+				}
+				eq, hasEq := and[0].(squirrel.Eq)
+				if !hasEq {
+					return false
+				}
+				_, hasArtist := eq["order_artist_name"]
+				return hasArtist
+			})).Return(artistTracks, nil).Maybe()
+		}
+
+		Context("when agent returns artist and album metadata", func() {
+			It("matches by title + artist MBID + album MBID (highest priority)", func() {
+				// Song in library with all MBIDs
+				correctMatch := model.MediaFile{
+					ID: "correct-match", Title: "Similar Song", Artist: "Depeche Mode", Album: "Violator",
+					MbzArtistID: "artist-mbid-123", MbzAlbumID: "album-mbid-456",
+				}
+				// Another song with same title but different MBIDs (should NOT match)
+				wrongMatch := model.MediaFile{
+					ID: "wrong-match", Title: "Similar Song", Artist: "Depeche Mode", Album: "Some Other Album",
+					MbzArtistID: "artist-mbid-123", MbzAlbumID: "different-album-mbid",
+				}
+				returnedSongs := []agents.Song{
+					{Name: "Similar Song", Artist: "Depeche Mode", ArtistMBID: "artist-mbid-123", Album: "Violator", AlbumMBID: "album-mbid-456"},
+				}
+
+				setupExpectations(returnedSongs, model.MediaFiles{}, model.MediaFiles{}, model.MediaFiles{wrongMatch, correctMatch})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("correct-match"))
+			})
+
+			It("matches by title + artist name + album name when MBIDs unavailable", func() {
+				// Song in library without MBIDs but with matching artist/album names
+				correctMatch := model.MediaFile{
+					ID: "correct-match", Title: "Similar Song", Artist: "depeche mode", Album: "violator",
+				}
+				// Another song with same title but different artist (should NOT match)
+				wrongMatch := model.MediaFile{
+					ID: "wrong-match", Title: "Similar Song", Artist: "Other Artist", Album: "Other Album",
+				}
+
+				returnedSongs := []agents.Song{
+					{Name: "Similar Song", Artist: "Depeche Mode", Album: "Violator"}, // No MBIDs
+				}
+
+				setupExpectations(returnedSongs, model.MediaFiles{}, model.MediaFiles{}, model.MediaFiles{wrongMatch, correctMatch})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("correct-match"))
+			})
+
+			It("matches by title + artist only when album info unavailable", func() {
+				// Song in library with matching artist
+				correctMatch := model.MediaFile{
+					ID: "correct-match", Title: "Similar Song", Artist: "depeche mode", Album: "Some Album",
+				}
+				// Another song with same title but different artist
+				wrongMatch := model.MediaFile{
+					ID: "wrong-match", Title: "Similar Song", Artist: "Other Artist", Album: "Other Album",
+				}
+				returnedSongs := []agents.Song{
+					{Name: "Similar Song", Artist: "Depeche Mode"}, // No album info
+				}
+
+				setupExpectations(returnedSongs, model.MediaFiles{}, model.MediaFiles{}, model.MediaFiles{wrongMatch, correctMatch})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("correct-match"))
+			})
+
+			It("does not match songs without artist info", func() {
+				// Songs without artist info cannot be matched since we query by artist
+				returnedSongs := []agents.Song{
+					{Name: "Similar Song"}, // No artist/album info at all
+				}
+
+				// No artist to query, so no GetAll calls for title matching
+				setupExpectations(returnedSongs, model.MediaFiles{}, model.MediaFiles{}, model.MediaFiles{})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(BeEmpty())
+			})
+		})
+
+		Context("when matching multiple songs with the same title but different artists", func() {
+			It("returns distinct matches for each artist's version (covers scenario)", func() {
+				// Multiple covers of the same song by different artists
+				cover1 := model.MediaFile{
+					ID: "cover-1", Title: "Yesterday", Artist: "The Beatles", Album: "Help!",
+				}
+				cover2 := model.MediaFile{
+					ID: "cover-2", Title: "Yesterday", Artist: "Ray Charles", Album: "Greatest Hits",
+				}
+				cover3 := model.MediaFile{
+					ID: "cover-3", Title: "Yesterday", Artist: "Frank Sinatra", Album: "My Way",
+				}
+
+				returnedSongs := []agents.Song{
+					{Name: "Yesterday", Artist: "The Beatles", Album: "Help!"},
+					{Name: "Yesterday", Artist: "Ray Charles", Album: "Greatest Hits"},
+					{Name: "Yesterday", Artist: "Frank Sinatra", Album: "My Way"},
+				}
+
+				setupExpectations(returnedSongs, model.MediaFiles{}, model.MediaFiles{}, model.MediaFiles{cover1, cover2, cover3})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				// All three covers should be returned, not just the first one
+				Expect(songs).To(HaveLen(3))
+				// Verify all three different versions are included
+				ids := []string{songs[0].ID, songs[1].ID, songs[2].ID}
+				Expect(ids).To(ContainElements("cover-1", "cover-2", "cover-3"))
+			})
+		})
+
+		Context("when matching multiple songs with different precision levels", func() {
+			It("prefers more precise matches for each song", func() {
+				// Library has multiple versions of same song
+				preciseMatch := model.MediaFile{
+					ID: "precise", Title: "Song A", Artist: "Artist One", Album: "Album One",
+					MbzArtistID: "mbid-1", MbzAlbumID: "album-mbid-1",
+				}
+				lessAccurateMatch := model.MediaFile{
+					ID: "less-accurate", Title: "Song A", Artist: "Artist One", Album: "Compilation",
+					MbzArtistID: "mbid-1",
+				}
+				artistTwoMatch := model.MediaFile{
+					ID: "artist-two", Title: "Song B", Artist: "Artist Two",
+				}
+
+				returnedSongs := []agents.Song{
+					{Name: "Song A", Artist: "Artist One", ArtistMBID: "mbid-1", Album: "Album One", AlbumMBID: "album-mbid-1"},
+					{Name: "Song B", Artist: "Artist Two"}, // Different artist
+				}
+
+				setupExpectations(returnedSongs, model.MediaFiles{}, model.MediaFiles{}, model.MediaFiles{lessAccurateMatch, preciseMatch, artistTwoMatch})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(2))
+				// First song should be the precise match (has all MBIDs)
+				Expect(songs[0].ID).To(Equal("precise"))
+				// Second song matches by title + artist
+				Expect(songs[1].ID).To(Equal("artist-two"))
+			})
+		})
+	})
+
+	Describe("Fuzzy matching fallback", func() {
+		var track model.MediaFile
+
+		BeforeEach(func() {
+			DeferCleanup(configtest.SetupConfig())
+			track = model.MediaFile{ID: "track-1", Title: "Test Track", Artist: "Test Artist"}
+
+			// Setup for GetEntityByID to return the track
+			artistRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+			albumRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+			mediaFileRepo.On("Get", "track-1").Return(&track, nil).Once()
+		})
+
+		Context("with default threshold (85%)", func() {
+			It("matches songs with remastered suffix", func() {
+				conf.Server.SimilarSongsMatchThreshold = 85
+
+				// Agent returns "Paranoid Android" but library has "Paranoid Android - Remastered"
+				returnedSongs := []agents.Song{
+					{Name: "Paranoid Android", Artist: "Radiohead"},
+				}
+				// Artist catalog has the remastered version (fuzzy match will find it)
+				artistTracks := model.MediaFiles{
+					{ID: "remastered", Title: "Paranoid Android - Remastered", Artist: "Radiohead"},
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, artistTracks)
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("remastered"))
+			})
+
+			It("matches songs with live suffix", func() {
+				conf.Server.SimilarSongsMatchThreshold = 85
+
+				returnedSongs := []agents.Song{
+					{Name: "Bohemian Rhapsody", Artist: "Queen"},
+				}
+				artistTracks := model.MediaFiles{
+					{ID: "live", Title: "Bohemian Rhapsody (Live)", Artist: "Queen"},
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, artistTracks)
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("live"))
+			})
+
+			It("does not match completely different songs", func() {
+				conf.Server.SimilarSongsMatchThreshold = 85
+
+				returnedSongs := []agents.Song{
+					{Name: "Yesterday", Artist: "The Beatles"},
+				}
+				// Artist catalog has completely different songs
+				artistTracks := model.MediaFiles{
+					{ID: "different", Title: "Tomorrow Never Knows", Artist: "The Beatles"},
+					{ID: "different2", Title: "Here Comes The Sun", Artist: "The Beatles"},
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, artistTracks)
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(BeEmpty())
+			})
+		})
+
+		Context("with threshold set to 100 (exact match only)", func() {
+			It("only matches exact titles", func() {
+				conf.Server.SimilarSongsMatchThreshold = 100
+
+				returnedSongs := []agents.Song{
+					{Name: "Paranoid Android", Artist: "Radiohead"},
+				}
+				// Artist catalog has only remastered version - no exact match
+				artistTracks := model.MediaFiles{
+					{ID: "remastered", Title: "Paranoid Android - Remastered", Artist: "Radiohead"},
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, artistTracks)
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(BeEmpty())
+			})
+		})
+
+		Context("with lower threshold (75%)", func() {
+			It("matches more aggressively", func() {
+				conf.Server.SimilarSongsMatchThreshold = 75
+
+				returnedSongs := []agents.Song{
+					{Name: "Song", Artist: "Artist"},
+				}
+				artistTracks := model.MediaFiles{
+					{ID: "extended", Title: "Song (Extended Mix)", Artist: "Artist"},
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, artistTracks)
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("extended"))
+			})
+		})
+
+		Context("with fuzzy album matching", func() {
+			It("matches album with (Remaster) suffix", func() {
+				conf.Server.SimilarSongsMatchThreshold = 85
+
+				// Agent returns "A Night at the Opera" but library has remastered version
+				returnedSongs := []agents.Song{
+					{Name: "Bohemian Rhapsody", Artist: "Queen", Album: "A Night at the Opera"},
+				}
+				// Library has same album with remaster suffix
+				correctMatch := model.MediaFile{
+					ID: "correct", Title: "Bohemian Rhapsody", Artist: "Queen", Album: "A Night at the Opera (2011 Remaster)",
+				}
+				wrongMatch := model.MediaFile{
+					ID: "wrong", Title: "Bohemian Rhapsody", Artist: "Queen", Album: "Greatest Hits",
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{wrongMatch, correctMatch})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				// Should prefer the fuzzy album match (Level 3) over title+artist only (Level 1)
+				Expect(songs[0].ID).To(Equal("correct"))
+			})
+
+			It("matches album with (Deluxe Edition) suffix", func() {
+				conf.Server.SimilarSongsMatchThreshold = 85
+
+				returnedSongs := []agents.Song{
+					{Name: "Enjoy the Silence", Artist: "Depeche Mode", Album: "Violator"},
+				}
+				correctMatch := model.MediaFile{
+					ID: "correct", Title: "Enjoy the Silence", Artist: "Depeche Mode", Album: "Violator (Deluxe Edition)",
+				}
+				wrongMatch := model.MediaFile{
+					ID: "wrong", Title: "Enjoy the Silence", Artist: "Depeche Mode", Album: "101",
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{wrongMatch, correctMatch})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("correct"))
+			})
+
+			It("prefers exact album match over fuzzy album match", func() {
+				conf.Server.SimilarSongsMatchThreshold = 85
+
+				returnedSongs := []agents.Song{
+					{Name: "Enjoy the Silence", Artist: "Depeche Mode", Album: "Violator"},
+				}
+				exactMatch := model.MediaFile{
+					ID: "exact", Title: "Enjoy the Silence", Artist: "Depeche Mode", Album: "Violator",
+				}
+				fuzzyMatch := model.MediaFile{
+					ID: "fuzzy", Title: "Enjoy the Silence", Artist: "Depeche Mode", Album: "Violator (Deluxe Edition)",
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{fuzzyMatch, exactMatch})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				// Both have same title similarity (1.0), so should prefer exact album match (higher specificity via higher album similarity)
+				Expect(songs[0].ID).To(Equal("exact"))
+			})
+		})
+	})
+
+	Describe("Duration matching", func() {
+		var track model.MediaFile
+
+		BeforeEach(func() {
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.SimilarSongsMatchThreshold = 100 // Exact title match for predictable tests
+
+			track = model.MediaFile{ID: "track-1", Title: "Test Track", Artist: "Test Artist"}
+
+			// Setup for GetEntityByID to return the track
+			artistRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+			albumRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+			mediaFileRepo.On("Get", "track-1").Return(&track, nil).Once()
+		})
+
+		Context("when agent provides duration", func() {
+			It("prefers tracks with matching duration", func() {
+				// Agent returns song with duration 180000ms (180 seconds)
+				returnedSongs := []agents.Song{
+					{Name: "Similar Song", Artist: "Test Artist", Duration: 180000},
+				}
+				// Library has two versions: one matching duration, one not
+				correctMatch := model.MediaFile{
+					ID: "correct", Title: "Similar Song", Artist: "Test Artist", Duration: 180.0,
+				}
+				wrongDuration := model.MediaFile{
+					ID: "wrong", Title: "Similar Song", Artist: "Test Artist", Duration: 240.0,
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{wrongDuration, correctMatch})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("correct"))
+			})
+
+			It("matches tracks with close duration", func() {
+				// Agent returns song with duration 180000ms (180 seconds)
+				returnedSongs := []agents.Song{
+					{Name: "Similar Song", Artist: "Test Artist", Duration: 180000},
+				}
+				// Library has track with 182.5 seconds (close to target)
+				closeDuration := model.MediaFile{
+					ID: "close-duration", Title: "Similar Song", Artist: "Test Artist", Duration: 182.5,
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{closeDuration})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("close-duration"))
+			})
+
+			It("prefers closer duration over farther duration", func() {
+				// Agent returns song with duration 180000ms (180 seconds)
+				returnedSongs := []agents.Song{
+					{Name: "Similar Song", Artist: "Test Artist", Duration: 180000},
+				}
+				// Library has one close, one far
+				closeDuration := model.MediaFile{
+					ID: "close", Title: "Similar Song", Artist: "Test Artist", Duration: 181.0,
+				}
+				farDuration := model.MediaFile{
+					ID: "far", Title: "Similar Song", Artist: "Test Artist", Duration: 190.0,
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{farDuration, closeDuration})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("close"))
+			})
+
+			It("still matches when no tracks have matching duration", func() {
+				// Agent returns song with duration 180000ms
+				returnedSongs := []agents.Song{
+					{Name: "Similar Song", Artist: "Test Artist", Duration: 180000},
+				}
+				// Library only has tracks with very different duration
+				differentDuration := model.MediaFile{
+					ID: "different", Title: "Similar Song", Artist: "Test Artist", Duration: 300.0,
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{differentDuration})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				// Duration mismatch doesn't exclude the track; it's just scored lower
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("different"))
+			})
+
+			It("prefers title match over duration match when titles differ", func() {
+				// Agent returns "Similar Song" with duration 180000ms
+				returnedSongs := []agents.Song{
+					{Name: "Similar Song", Artist: "Test Artist", Duration: 180000},
+				}
+				// Library has:
+				// - differentTitle: matches duration but has different title (won't pass title threshold)
+				// - correctTitle: doesn't match duration but has correct title (wins on title similarity)
+				differentTitle := model.MediaFile{
+					ID: "wrong-title", Title: "Different Song", Artist: "Test Artist", Duration: 180.0,
+				}
+				correctTitle := model.MediaFile{
+					ID: "correct-title", Title: "Similar Song", Artist: "Test Artist", Duration: 300.0,
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{differentTitle, correctTitle})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				// Title similarity is the top priority, so the correct title wins despite duration mismatch
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("correct-title"))
+			})
+		})
+
+		Context("when agent does not provide duration", func() {
+			It("matches without duration filtering (duration=0)", func() {
+				// Agent returns song without duration
+				returnedSongs := []agents.Song{
+					{Name: "Similar Song", Artist: "Test Artist", Duration: 0},
+				}
+				// Library tracks with various durations should all be candidates
+				anyTrack := model.MediaFile{
+					ID: "any", Title: "Similar Song", Artist: "Test Artist", Duration: 999.0,
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{anyTrack})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("any"))
+			})
+		})
+
+		Context("edge cases", func() {
+			It("handles very short songs with close duration", func() {
+				// 30-second song with 1-second difference
+				returnedSongs := []agents.Song{
+					{Name: "Short Song", Artist: "Test Artist", Duration: 30000},
+				}
+				shortTrack := model.MediaFile{
+					ID: "short", Title: "Short Song", Artist: "Test Artist", Duration: 31.0,
+				}
+
+				setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{shortTrack})
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("short"))
+			})
+		})
+	})
+
+	Describe("Deduplication of mismatched songs", func() {
+		var track model.MediaFile
+
+		BeforeEach(func() {
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.SimilarSongsMatchThreshold = 85 // Allow fuzzy matching
+
+			track = model.MediaFile{ID: "track-1", Title: "Test Track", Artist: "Test Artist"}
+
+			// Setup for GetEntityByID to return the track
+			artistRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+			albumRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+			mediaFileRepo.On("Get", "track-1").Return(&track, nil).Once()
+		})
+
+		It("removes duplicates when different input songs match the same library track", func() {
+			// Agent returns two different versions that will both fuzzy-match to the same library track
+			returnedSongs := []agents.Song{
+				{Name: "Bohemian Rhapsody (Live)", Artist: "Queen"},
+				{Name: "Bohemian Rhapsody (Original Mix)", Artist: "Queen"},
+			}
+			// Library only has one version
+			libraryTrack := model.MediaFile{
+				ID: "br-live", Title: "Bohemian Rhapsody (Live)", Artist: "Queen",
+			}
+
+			setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{libraryTrack})
+
+			songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+			Expect(err).ToNot(HaveOccurred())
+			// Should only return one track, not two duplicates
+			Expect(songs).To(HaveLen(1))
+			Expect(songs[0].ID).To(Equal("br-live"))
+		})
+
+		It("preserves duplicates when identical input songs match the same library track", func() {
+			// Agent returns the exact same song twice (intentional repetition)
+			returnedSongs := []agents.Song{
+				{Name: "Bohemian Rhapsody", Artist: "Queen", Album: "A Night at the Opera"},
+				{Name: "Bohemian Rhapsody", Artist: "Queen", Album: "A Night at the Opera"},
+			}
+			// Library has matching track
+			libraryTrack := model.MediaFile{
+				ID: "br", Title: "Bohemian Rhapsody", Artist: "Queen", Album: "A Night at the Opera",
+			}
+
+			setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{libraryTrack})
+
+			songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+			Expect(err).ToNot(HaveOccurred())
+			// Should return two tracks since input songs were identical
+			Expect(songs).To(HaveLen(2))
+			Expect(songs[0].ID).To(Equal("br"))
+			Expect(songs[1].ID).To(Equal("br"))
+		})
+
+		It("handles mixed scenario with both identical and different input songs", func() {
+			// Agent returns: Song A, Song B (different from A), Song A again (same as first)
+			// All three match to the same library track
+			returnedSongs := []agents.Song{
+				{Name: "Yesterday", Artist: "The Beatles", Album: "Help!"},
+				{Name: "Yesterday (Remastered)", Artist: "The Beatles", Album: "1"},        // Different version
+				{Name: "Yesterday", Artist: "The Beatles", Album: "Help!"},                 // Same as first
+				{Name: "Yesterday (Anthology)", Artist: "The Beatles", Album: "Anthology"}, // Another different version
+			}
+			// Library only has one version
+			libraryTrack := model.MediaFile{
+				ID: "yesterday", Title: "Yesterday", Artist: "The Beatles", Album: "Help!",
+			}
+
+			setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{libraryTrack})
+
+			songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+			Expect(err).ToNot(HaveOccurred())
+			// Should return 2 tracks:
+			// 1. First "Yesterday" (original)
+			// 2. Third "Yesterday" (same as first, so kept)
+			// Skip: Second "Yesterday (Remastered)" (different input, same library track)
+			// Skip: Fourth "Yesterday (Anthology)" (different input, same library track)
+			Expect(songs).To(HaveLen(2))
+			Expect(songs[0].ID).To(Equal("yesterday"))
+			Expect(songs[1].ID).To(Equal("yesterday"))
+		})
+
+		It("does not deduplicate songs that match different library tracks", func() {
+			// Agent returns different songs that match different library tracks
+			returnedSongs := []agents.Song{
+				{Name: "Song A", Artist: "Artist"},
+				{Name: "Song B", Artist: "Artist"},
+				{Name: "Song C", Artist: "Artist"},
+			}
+			// Library has all three songs
+			trackA := model.MediaFile{ID: "track-a", Title: "Song A", Artist: "Artist"}
+			trackB := model.MediaFile{ID: "track-b", Title: "Song B", Artist: "Artist"}
+			trackC := model.MediaFile{ID: "track-c", Title: "Song C", Artist: "Artist"}
+
+			setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{trackA, trackB, trackC})
+
+			songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+			Expect(err).ToNot(HaveOccurred())
+			// All three should be returned since they match different library tracks
+			Expect(songs).To(HaveLen(3))
+			Expect(songs[0].ID).To(Equal("track-a"))
+			Expect(songs[1].ID).To(Equal("track-b"))
+			Expect(songs[2].ID).To(Equal("track-c"))
+		})
+
+		It("respects count limit after deduplication", func() {
+			// Agent returns 4 songs: 2 unique + 2 that would create duplicates
+			returnedSongs := []agents.Song{
+				{Name: "Song A", Artist: "Artist"},
+				{Name: "Song A (Live)", Artist: "Artist"}, // Different, matches same track
+				{Name: "Song B", Artist: "Artist"},
+				{Name: "Song B (Remix)", Artist: "Artist"}, // Different, matches same track
+			}
+			trackA := model.MediaFile{ID: "track-a", Title: "Song A", Artist: "Artist"}
+			trackB := model.MediaFile{ID: "track-b", Title: "Song B", Artist: "Artist"}
+
+			setupSimilarSongsExpectations(returnedSongs, model.MediaFiles{trackA, trackB})
+
+			// Request only 2 songs
+			songs, err := provider.SimilarSongs(ctx, "track-1", 2)
+
+			Expect(err).ToNot(HaveOccurred())
+			// Should return exactly 2: Song A and Song B (skipping duplicates)
+			Expect(songs).To(HaveLen(2))
+			Expect(songs[0].ID).To(Equal("track-a"))
+			Expect(songs[1].ID).To(Equal("track-b"))
+		})
+	})
+})

core/external/provider_similarsongs_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 
+	"github.com/Masterminds/squirrel"
 	"github.com/navidrome/navidrome/core/agents"
 	. "github.com/navidrome/navidrome/core/external"
 	"github.com/navidrome/navidrome/model"
@@ -19,9 +20,10 @@ var _ = Describe("Provider - SimilarSongs", func() {
 	var mockAgent *mockSimilarArtistAgent
 	var mockTopAgent agents.ArtistTopSongsRetriever
 	var mockSimilarAgent agents.ArtistSimilarRetriever
-	var agentsCombined Agents
+	var agentsCombined *mockAgents
 	var artistRepo *mockArtistRepo
 	var mediaFileRepo *mockMediaFileRepo
+	var albumRepo *mockAlbumRepo
 	var ctx context.Context
 
 	BeforeEach(func() {
@@ -29,10 +31,12 @@ var _ = Describe("Provider - SimilarSongs", func() {
 
 		artistRepo = newMockArtistRepo()
 		mediaFileRepo = newMockMediaFileRepo()
+		albumRepo = newMockAlbumRepo()
 
 		ds = &tests.MockDataStore{
 			MockedArtist:    artistRepo,
 			MockedMediaFile: mediaFileRepo,
+			MockedAlbum:     albumRepo,
 		}
 
 		mockAgent = &mockSimilarArtistAgent{}
@@ -47,12 +51,230 @@ var _ = Describe("Provider - SimilarSongs", func() {
 		provider = NewProvider(ds, agentsCombined)
 	})
 
+	Describe("dispatch by entity type", func() {
+		Context("when ID is a MediaFile (track)", func() {
+			It("calls GetSimilarSongsByTrack and returns matched songs", func() {
+				track := model.MediaFile{ID: "track-1", Title: "Just Can't Get Enough", Artist: "Depeche Mode", MbzRecordingID: "track-mbid"}
+				matchedSong := model.MediaFile{ID: "matched-1", Title: "Dreaming of Me", Artist: "Depeche Mode"}
+
+				// GetEntityByID tries Artist, Album, Playlist, then MediaFile
+				artistRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+				albumRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+				mediaFileRepo.On("Get", "track-1").Return(&track, nil).Once()
+
+				agentsCombined.On("GetSimilarSongsByTrack", mock.Anything, "track-1", "Just Can't Get Enough", "Depeche Mode", "track-mbid", 5).
+					Return([]agents.Song{
+						{Name: "Dreaming of Me", MBID: "", Artist: "Depeche Mode", ArtistMBID: "artist-mbid"},
+					}, nil).Once()
+
+				// Mock loadTracksByID - no ID matches
+				mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					_, ok := opt.Filters.(squirrel.Eq)
+					return ok
+				})).Return(model.MediaFiles{}, nil).Once()
+
+				// Mock loadTracksByMBID - no MBID matches (empty MBID means this won't be called)
+				mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					and, ok := opt.Filters.(squirrel.And)
+					if !ok || len(and) < 1 {
+						return false
+					}
+					eq, hasEq := and[0].(squirrel.Eq)
+					if !hasEq {
+						return false
+					}
+					_, hasMBID := eq["mbz_recording_id"]
+					return hasMBID
+				})).Return(model.MediaFiles{}, nil).Maybe()
+
+				// Mock loadTracksByTitleAndArtist - queries by artist name
+				mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					and, ok := opt.Filters.(squirrel.And)
+					if !ok || len(and) < 2 {
+						return false
+					}
+					eq, hasEq := and[0].(squirrel.Eq)
+					if !hasEq {
+						return false
+					}
+					_, hasArtist := eq["order_artist_name"]
+					return hasArtist
+				})).Return(model.MediaFiles{matchedSong}, nil).Maybe()
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("matched-1"))
+			})
+
+			It("falls back to artist-based algorithm when GetSimilarSongsByTrack returns empty", func() {
+				track := model.MediaFile{ID: "track-1", Title: "Track", Artist: "Artist", ArtistID: "artist-1"}
+				artist := model.Artist{ID: "artist-1", Name: "Artist"}
+				song := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "mbid-1"}
+
+				// GetEntityByID for the initial call tries Artist, Album, Playlist, then MediaFile
+				artistRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+				albumRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+				mediaFileRepo.On("Get", "track-1").Return(&track, nil).Once()
+
+				agentsCombined.On("GetSimilarSongsByTrack", mock.Anything, "track-1", "Track", "Artist", "", mock.Anything).
+					Return([]agents.Song{}, nil).Once()
+
+				// Fallback calls getArtist(id) which calls GetEntityByID again - this time it finds the mediafile
+				// and recursively calls getArtist(v.ArtistID)
+				artistRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+				albumRepo.On("Get", "track-1").Return(nil, model.ErrNotFound).Once()
+				mediaFileRepo.On("Get", "track-1").Return(&track, nil).Once()
+
+				// Then it recurses with the artist-1 ID
+				artistRepo.On("Get", "artist-1").Return(&artist, nil).Maybe()
+				artistRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					return opt.Max == 1 && opt.Filters != nil
+				})).Return(model.Artists{artist}, nil).Maybe()
+
+				mockAgent.On("GetSimilarArtists", mock.Anything, "artist-1", "Artist", "", 15).
+					Return([]agents.Artist{}, nil).Once()
+
+				artistRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					return opt.Max == 0 && opt.Filters != nil
+				})).Return(model.Artists{}, nil).Once()
+
+				mockAgent.On("GetArtistTopSongs", mock.Anything, "artist-1", "Artist", "", mock.Anything).
+					Return([]agents.Song{{Name: "Song One", MBID: "mbid-1"}}, nil).Once()
+
+				mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song}, nil).Once()
+
+				songs, err := provider.SimilarSongs(ctx, "track-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("song-1"))
+			})
+		})
+
+		Context("when ID is an Album", func() {
+			It("calls GetSimilarSongsByAlbum and returns matched songs", func() {
+				album := model.Album{ID: "album-1", Name: "Speak & Spell", AlbumArtist: "Depeche Mode", MbzAlbumID: "album-mbid"}
+				matchedSong := model.MediaFile{ID: "matched-1", Title: "New Life", Artist: "Depeche Mode", MbzRecordingID: "song-mbid"}
+
+				// GetEntityByID tries Artist, Album, Playlist, then MediaFile
+				artistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once()
+				albumRepo.On("Get", "album-1").Return(&album, nil).Once()
+
+				agentsCombined.On("GetSimilarSongsByAlbum", mock.Anything, "album-1", "Speak & Spell", "Depeche Mode", "album-mbid", 5).
+					Return([]agents.Song{
+						{Name: "New Life", MBID: "song-mbid", Artist: "Depeche Mode"},
+					}, nil).Once()
+
+				// Mock loadTracksByID - no ID matches
+				mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					_, ok := opt.Filters.(squirrel.Eq)
+					return ok
+				})).Return(model.MediaFiles{}, nil).Once()
+
+				// Mock loadTracksByMBID - MBID match
+				mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					and, ok := opt.Filters.(squirrel.And)
+					if !ok || len(and) < 1 {
+						return false
+					}
+					_, hasEq := and[0].(squirrel.Eq)
+					return hasEq
+				})).Return(model.MediaFiles{matchedSong}, nil).Once()
+
+				songs, err := provider.SimilarSongs(ctx, "album-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("matched-1"))
+			})
+
+			It("falls back when GetSimilarSongsByAlbum returns ErrNotFound", func() {
+				album := model.Album{ID: "album-1", Name: "Album", AlbumArtist: "Artist", AlbumArtistID: "artist-1"}
+				artist := model.Artist{ID: "artist-1", Name: "Artist"}
+				song := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "mbid-1"}
+
+				// GetEntityByID for the initial call tries Artist, Album, Playlist, then MediaFile
+				artistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once()
+				albumRepo.On("Get", "album-1").Return(&album, nil).Once()
+
+				agentsCombined.On("GetSimilarSongsByAlbum", mock.Anything, "album-1", "Album", "Artist", "", mock.Anything).
+					Return(nil, agents.ErrNotFound).Once()
+
+				// Fallback calls getArtist(id) which calls GetEntityByID again - this time it finds the album
+				// and recursively calls getArtist(v.AlbumArtistID)
+				artistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once()
+				albumRepo.On("Get", "album-1").Return(&album, nil).Once()
+
+				// Then it recurses with the artist-1 ID
+				artistRepo.On("Get", "artist-1").Return(&artist, nil).Maybe()
+				artistRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					return opt.Max == 1 && opt.Filters != nil
+				})).Return(model.Artists{artist}, nil).Maybe()
+
+				mockAgent.On("GetSimilarArtists", mock.Anything, "artist-1", "Artist", "", 15).
+					Return([]agents.Artist{}, nil).Once()
+
+				artistRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					return opt.Max == 0 && opt.Filters != nil
+				})).Return(model.Artists{}, nil).Once()
+
+				mockAgent.On("GetArtistTopSongs", mock.Anything, "artist-1", "Artist", "", mock.Anything).
+					Return([]agents.Song{{Name: "Song One", MBID: "mbid-1"}}, nil).Once()
+
+				mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song}, nil).Once()
+
+				songs, err := provider.SimilarSongs(ctx, "album-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("song-1"))
+			})
+		})
+
+		Context("when ID is an Artist", func() {
+			It("calls GetSimilarSongsByArtist and returns matched songs", func() {
+				artist := model.Artist{ID: "artist-1", Name: "Depeche Mode", MbzArtistID: "artist-mbid"}
+				matchedSong := model.MediaFile{ID: "matched-1", Title: "Enjoy the Silence", Artist: "Depeche Mode", MbzRecordingID: "song-mbid"}
+
+				artistRepo.On("Get", "artist-1").Return(&artist, nil).Once()
+				agentsCombined.On("GetSimilarSongsByArtist", mock.Anything, "artist-1", "Depeche Mode", "artist-mbid", 5).
+					Return([]agents.Song{
+						{Name: "Enjoy the Silence", MBID: "song-mbid", Artist: "Depeche Mode"},
+					}, nil).Once()
+
+				// Mock loadTracksByID - no ID matches
+				mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					_, ok := opt.Filters.(squirrel.Eq)
+					return ok
+				})).Return(model.MediaFiles{}, nil).Once()
+
+				// Mock loadTracksByMBID - MBID match
+				mediaFileRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+					and, ok := opt.Filters.(squirrel.And)
+					if !ok || len(and) < 1 {
+						return false
+					}
+					_, hasEq := and[0].(squirrel.Eq)
+					return hasEq
+				})).Return(model.MediaFiles{matchedSong}, nil).Once()
+
+				songs, err := provider.SimilarSongs(ctx, "artist-1", 5)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(songs).To(HaveLen(1))
+				Expect(songs[0].ID).To(Equal("matched-1"))
+			})
+		})
+	})
+
 	It("returns similar songs from main artist and similar artists", func() {
 		artist1 := model.Artist{ID: "artist-1", Name: "Artist One"}
 		similarArtist := model.Artist{ID: "artist-3", Name: "Similar Artist"}
-		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1"}
-		song2 := model.MediaFile{ID: "song-2", Title: "Song Two", ArtistID: "artist-1"}
-		song3 := model.MediaFile{ID: "song-3", Title: "Song Three", ArtistID: "artist-3"}
+		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "mbid-1"}
+		song2 := model.MediaFile{ID: "song-2", Title: "Song Two", ArtistID: "artist-1", MbzRecordingID: "mbid-2"}
+		song3 := model.MediaFile{ID: "song-3", Title: "Song Three", ArtistID: "artist-3", MbzRecordingID: "mbid-3"}
 
 		artistRepo.On("Get", "artist-1").Return(&artist1, nil).Maybe()
 		artistRepo.On("Get", "artist-3").Return(&similarArtist, nil).Maybe()
@@ -61,14 +283,26 @@ var _ = Describe("Provider - SimilarSongs", func() {
 			return opt.Max == 1 && opt.Filters != nil
 		})).Return(model.Artists{artist1}, nil).Once()
 
+		// New similar songs by artist returns ErrNotFound to trigger fallback
+		agentsCombined.On("GetSimilarSongsByArtist", mock.Anything, "artist-1", "Artist One", "", mock.Anything).
+			Return(nil, agents.ErrNotFound).Once()
+
 		similarAgentsResp := []agents.Artist{
 			{Name: "Similar Artist", MBID: "similar-mbid"},
 		}
 		mockAgent.On("GetSimilarArtists", mock.Anything, "artist-1", "Artist One", "", 15).
 			Return(similarAgentsResp, nil).Once()
 
+		// Mock the three-phase artist lookup: ID (skipped - no IDs), MBID, then Name
+		// MBID lookup returns empty (no match)
 		artistRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
-			return opt.Max == 0 && opt.Filters != nil
+			_, ok := opt.Filters.(squirrel.Eq)
+			return opt.Max == 0 && ok
+		})).Return(model.Artists{}, nil).Once()
+		// Name lookup returns the similar artist
+		artistRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
+			_, ok := opt.Filters.(squirrel.Or)
+			return opt.Max == 0 && ok
 		})).Return(model.Artists{similarArtist}, nil).Once()
 
 		mockAgent.On("GetArtistTopSongs", mock.Anything, "artist-1", "Artist One", "", mock.Anything).
@@ -82,9 +316,8 @@ var _ = Describe("Provider - SimilarSongs", func() {
 				{Name: "Song Three", MBID: "mbid-3"},
 			}, nil).Once()
 
-		mediaFileRepo.FindByMBID("mbid-1", song1)
-		mediaFileRepo.FindByMBID("mbid-2", song2)
-		mediaFileRepo.FindByMBID("mbid-3", song3)
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1, song2}, nil).Once()
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song3}, nil).Once()
 
 		songs, err := provider.SimilarSongs(ctx, "artist-1", 3)
 
@@ -98,6 +331,7 @@ var _ = Describe("Provider - SimilarSongs", func() {
 	It("returns ErrNotFound when artist is not found", func() {
 		artistRepo.On("Get", "artist-unknown-artist").Return(nil, model.ErrNotFound)
 		mediaFileRepo.On("Get", "artist-unknown-artist").Return(nil, model.ErrNotFound)
+		albumRepo.On("Get", "artist-unknown-artist").Return(nil, model.ErrNotFound)
 
 		artistRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
 			return opt.Max == 1 && opt.Filters != nil
@@ -111,13 +345,17 @@ var _ = Describe("Provider - SimilarSongs", func() {
 
 	It("returns songs from main artist when GetSimilarArtists returns error", func() {
 		artist1 := model.Artist{ID: "artist-1", Name: "Artist One"}
-		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1"}
+		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "mbid-1"}
 
 		artistRepo.On("Get", "artist-1").Return(&artist1, nil).Maybe()
 		artistRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
 			return opt.Max == 1 && opt.Filters != nil
 		})).Return(model.Artists{artist1}, nil).Maybe()
 
+		// New similar songs by artist returns ErrNotFound to trigger fallback
+		agentsCombined.On("GetSimilarSongsByArtist", mock.Anything, "artist-1", "Artist One", "", mock.Anything).
+			Return(nil, agents.ErrNotFound).Once()
+
 		mockAgent.On("GetSimilarArtists", mock.Anything, "artist-1", "Artist One", "", 15).
 			Return(nil, errors.New("error getting similar artists")).Once()
 
@@ -130,7 +368,7 @@ var _ = Describe("Provider - SimilarSongs", func() {
 				{Name: "Song One", MBID: "mbid-1"},
 			}, nil).Once()
 
-		mediaFileRepo.FindByMBID("mbid-1", song1)
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1}, nil).Once()
 
 		songs, err := provider.SimilarSongs(ctx, "artist-1", 5)
 
@@ -147,6 +385,10 @@ var _ = Describe("Provider - SimilarSongs", func() {
 			return opt.Max == 1 && opt.Filters != nil
 		})).Return(model.Artists{artist1}, nil).Maybe()
 
+		// New similar songs by artist returns ErrNotFound to trigger fallback
+		agentsCombined.On("GetSimilarSongsByArtist", mock.Anything, "artist-1", "Artist One", "", mock.Anything).
+			Return(nil, agents.ErrNotFound).Once()
+
 		mockAgent.On("GetSimilarArtists", mock.Anything, "artist-1", "Artist One", "", 15).
 			Return([]agents.Artist{}, nil).Once()
 
@@ -165,14 +407,18 @@ var _ = Describe("Provider - SimilarSongs", func() {
 
 	It("respects count parameter", func() {
 		artist1 := model.Artist{ID: "artist-1", Name: "Artist One"}
-		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1"}
-		song2 := model.MediaFile{ID: "song-2", Title: "Song Two", ArtistID: "artist-1"}
+		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "mbid-1"}
+		song2 := model.MediaFile{ID: "song-2", Title: "Song Two", ArtistID: "artist-1", MbzRecordingID: "mbid-2"}
 
 		artistRepo.On("Get", "artist-1").Return(&artist1, nil).Maybe()
 		artistRepo.On("GetAll", mock.MatchedBy(func(opt model.QueryOptions) bool {
 			return opt.Max == 1 && opt.Filters != nil
 		})).Return(model.Artists{artist1}, nil).Maybe()
 
+		// New similar songs by artist returns ErrNotFound to trigger fallback
+		agentsCombined.On("GetSimilarSongsByArtist", mock.Anything, "artist-1", "Artist One", "", mock.Anything).
+			Return(nil, agents.ErrNotFound).Once()
+
 		mockAgent.On("GetSimilarArtists", mock.Anything, "artist-1", "Artist One", "", 15).
 			Return([]agents.Artist{}, nil).Once()
 
@@ -186,8 +432,7 @@ var _ = Describe("Provider - SimilarSongs", func() {
 				{Name: "Song Two", MBID: "mbid-2"},
 			}, nil).Once()
 
-		mediaFileRepo.FindByMBID("mbid-1", song1)
-		mediaFileRepo.FindByMBID("mbid-2", song2)
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1, song2}, nil).Once()
 
 		songs, err := provider.SimilarSongs(ctx, "artist-1", 1)
 

core/external/provider_topsongs_test.go

@@ -4,10 +4,12 @@ import (
 	"context"
 	"errors"
 
+	_ "github.com/navidrome/navidrome/adapters/lastfm"
+	_ "github.com/navidrome/navidrome/adapters/listenbrainz"
+	_ "github.com/navidrome/navidrome/adapters/spotify"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
 	"github.com/navidrome/navidrome/core/agents"
-	_ "github.com/navidrome/navidrome/core/agents/lastfm"
-	_ "github.com/navidrome/navidrome/core/agents/listenbrainz"
-	_ "github.com/navidrome/navidrome/core/agents/spotify"
 	. "github.com/navidrome/navidrome/core/external"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/tests"
@@ -26,6 +28,10 @@ var _ = Describe("Provider - TopSongs", func() {
 	)
 
 	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+		// Disable fuzzy matching for these tests to avoid unexpected GetAll calls
+		conf.Server.SimilarSongsMatchThreshold = 100
+
 		ctx = GinkgoT().Context()
 
 		artistRepo = newMockArtistRepo()       // Use helper mock
@@ -42,10 +48,6 @@ var _ = Describe("Provider - TopSongs", func() {
 		p = NewProvider(ds, ag)
 	})
 
-	BeforeEach(func() {
-		// Setup expectations in individual tests
-	})
-
 	It("returns top songs for a known artist", func() {
 		// Mock finding the artist
 		artist1 := model.Artist{ID: "artist-1", Name: "Artist One", MbzArtistID: "mbid-artist-1"}
@@ -58,11 +60,10 @@ var _ = Describe("Provider - TopSongs", func() {
 		}
 		ag.On("GetArtistTopSongs", ctx, "artist-1", "Artist One", "mbid-artist-1", 2).Return(agentSongs, nil).Once()
 
-		// Mock finding matching tracks
+		// Mock finding matching tracks (both returned in a single query)
 		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "mbid-song-1"}
 		song2 := model.MediaFile{ID: "song-2", Title: "Song Two", ArtistID: "artist-1", MbzRecordingID: "mbid-song-2"}
-		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1}, nil).Once()
-		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song2}, nil).Once()
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1, song2}, nil).Once()
 
 		songs, err := p.TopSongs(ctx, "Artist One", 2)
 
@@ -155,11 +156,10 @@ var _ = Describe("Provider - TopSongs", func() {
 		}
 		ag.On("GetArtistTopSongs", ctx, "artist-1", "Artist One", "mbid-artist-1", 2).Return(agentSongs, nil).Once()
 
-		// Mock finding matching tracks (only find song 1)
+		// Mock finding matching tracks (only find song 1 on bulk query)
 		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "mbid-song-1"}
-		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1}, nil).Once()
-		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{}, nil).Once() // For mbid-song-2 (fails)
-		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{}, nil).Once() // For title fallback (fails)
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1}, nil).Once() // bulk MBID query
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{}, nil).Once()      // title fallback for song2
 
 		songs, err := p.TopSongs(ctx, "Artist One", 2)
 
@@ -190,4 +190,147 @@ var _ = Describe("Provider - TopSongs", func() {
 		artistRepo.AssertExpectations(GinkgoT())
 		ag.AssertExpectations(GinkgoT())
 	})
+
+	It("falls back to title matching when MbzRecordingID is missing", func() {
+		// Mock finding the artist
+		artist1 := model.Artist{ID: "artist-1", Name: "Artist One", MbzArtistID: "mbid-artist-1"}
+		artistRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.Artists{artist1}, nil).Once()
+
+		// Mock agent response with songs that have NO MBID (empty string)
+		agentSongs := []agents.Song{
+			{Name: "Song One", MBID: ""}, // No MBID, should fall back to title matching
+			{Name: "Song Two", MBID: ""}, // No MBID, should fall back to title matching
+		}
+		ag.On("GetArtistTopSongs", ctx, "artist-1", "Artist One", "mbid-artist-1", 2).Return(agentSongs, nil).Once()
+
+		// Since there are no MBIDs, loadTracksByMBID should not make any database call
+		// loadTracksByTitle should make a database call for title matching
+		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "", OrderTitle: "song one"}
+		song2 := model.MediaFile{ID: "song-2", Title: "Song Two", ArtistID: "artist-1", MbzRecordingID: "", OrderTitle: "song two"}
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1, song2}, nil).Once()
+
+		songs, err := p.TopSongs(ctx, "Artist One", 2)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(songs).To(HaveLen(2))
+		Expect(songs[0].ID).To(Equal("song-1"))
+		Expect(songs[1].ID).To(Equal("song-2"))
+		artistRepo.AssertExpectations(GinkgoT())
+		ag.AssertExpectations(GinkgoT())
+		mediaFileRepo.AssertExpectations(GinkgoT())
+	})
+
+	It("combines MBID and title matching when some songs have missing MbzRecordingID", func() {
+		// Mock finding the artist
+		artist1 := model.Artist{ID: "artist-1", Name: "Artist One", MbzArtistID: "mbid-artist-1"}
+		artistRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.Artists{artist1}, nil).Once()
+
+		// Mock agent response with mixed MBID availability
+		agentSongs := []agents.Song{
+			{Name: "Song One", MBID: "mbid-song-1"}, // Has MBID, should match by MBID
+			{Name: "Song Two", MBID: ""},            // No MBID, should fall back to title matching
+		}
+		ag.On("GetArtistTopSongs", ctx, "artist-1", "Artist One", "mbid-artist-1", 2).Return(agentSongs, nil).Once()
+
+		// Mock the MBID query (finds song1 by MBID)
+		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "mbid-song-1", OrderTitle: "song one"}
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1}, nil).Once()
+
+		// Mock the title fallback query (finds song2 by title)
+		song2 := model.MediaFile{ID: "song-2", Title: "Song Two", ArtistID: "artist-1", MbzRecordingID: "", OrderTitle: "song two"}
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song2}, nil).Once()
+
+		songs, err := p.TopSongs(ctx, "Artist One", 2)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(songs).To(HaveLen(2))
+		Expect(songs[0].ID).To(Equal("song-1")) // Found by MBID
+		Expect(songs[1].ID).To(Equal("song-2")) // Found by title
+		artistRepo.AssertExpectations(GinkgoT())
+		ag.AssertExpectations(GinkgoT())
+		mediaFileRepo.AssertExpectations(GinkgoT())
+	})
+
+	It("only returns requested count when provider returns additional items", func() {
+		// Mock finding the artist
+		artist1 := model.Artist{ID: "artist-1", Name: "Artist One", MbzArtistID: "mbid-artist-1"}
+		artistRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.Artists{artist1}, nil).Once()
+
+		// Mock agent response
+		agentSongs := []agents.Song{
+			{Name: "Song One", MBID: "mbid-song-1"},
+			{Name: "Song Two", MBID: "mbid-song-2"},
+		}
+		ag.On("GetArtistTopSongs", ctx, "artist-1", "Artist One", "mbid-artist-1", 1).Return(agentSongs, nil).Once()
+
+		// Mock finding matching tracks (both returned in a single query)
+		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "mbid-song-1"}
+		song2 := model.MediaFile{ID: "song-2", Title: "Song Two", ArtistID: "artist-1", MbzRecordingID: "mbid-song-2"}
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1, song2}, nil).Once()
+
+		songs, err := p.TopSongs(ctx, "Artist One", 1)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(songs).To(HaveLen(1))
+		Expect(songs[0].ID).To(Equal("song-1"))
+		artistRepo.AssertExpectations(GinkgoT())
+		ag.AssertExpectations(GinkgoT())
+		mediaFileRepo.AssertExpectations(GinkgoT())
+	})
+
+	It("matches songs by ID first when agent provides IDs", func() {
+		// Mock finding the artist
+		artist1 := model.Artist{ID: "artist-1", Name: "Artist One", MbzArtistID: "mbid-artist-1"}
+		artistRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.Artists{artist1}, nil).Once()
+
+		// Mock agent response with IDs provided (highest priority matching)
+		// Note: Songs have no MBID to ensure only ID matching is used
+		agentSongs := []agents.Song{
+			{ID: "song-1", Name: "Song One"},
+			{ID: "song-2", Name: "Song Two"},
+		}
+		ag.On("GetArtistTopSongs", ctx, "artist-1", "Artist One", "mbid-artist-1", 2).Return(agentSongs, nil).Once()
+
+		// Mock ID lookup (first query - should match both songs directly)
+		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1"}
+		song2 := model.MediaFile{ID: "song-2", Title: "Song Two", ArtistID: "artist-1"}
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1, song2}, nil).Once()
+
+		songs, err := p.TopSongs(ctx, "Artist One", 2)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(songs).To(HaveLen(2))
+		Expect(songs[0].ID).To(Equal("song-1"))
+		Expect(songs[1].ID).To(Equal("song-2"))
+		artistRepo.AssertExpectations(GinkgoT())
+		ag.AssertExpectations(GinkgoT())
+		mediaFileRepo.AssertExpectations(GinkgoT())
+	})
+
+	It("falls back to MBID when ID is not found", func() {
+		// Mock finding the artist
+		artist1 := model.Artist{ID: "artist-1", Name: "Artist One", MbzArtistID: "mbid-artist-1"}
+		artistRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.Artists{artist1}, nil).Once()
+
+		// Mock agent response with ID that won't be found, but MBID that will
+		agentSongs := []agents.Song{
+			{ID: "non-existent-id", Name: "Song One", MBID: "mbid-song-1"},
+		}
+		ag.On("GetArtistTopSongs", ctx, "artist-1", "Artist One", "mbid-artist-1", 1).Return(agentSongs, nil).Once()
+
+		// Mock ID lookup - returns empty (ID not found)
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{}, nil).Once()
+		// Mock MBID lookup - finds the song
+		song1 := model.MediaFile{ID: "song-1", Title: "Song One", ArtistID: "artist-1", MbzRecordingID: "mbid-song-1"}
+		mediaFileRepo.On("GetAll", mock.AnythingOfType("model.QueryOptions")).Return(model.MediaFiles{song1}, nil).Once()
+
+		songs, err := p.TopSongs(ctx, "Artist One", 1)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(songs).To(HaveLen(1))
+		Expect(songs[0].ID).To(Equal("song-1"))
+		artistRepo.AssertExpectations(GinkgoT())
+		ag.AssertExpectations(GinkgoT())
+		mediaFileRepo.AssertExpectations(GinkgoT())
+	})
 })

core/external/provider_updatealbuminfo_test.go

@@ -59,13 +59,13 @@ var _ = Describe("Provider - UpdateAlbumInfo", func() {
 		expectedInfo := &agents.AlbumInfo{
 			URL:         "http://example.com/album",
 			Description: "Album Description",
-			Images: []agents.ExternalImage{
-				{URL: "http://example.com/large.jpg", Size: 300},
-				{URL: "http://example.com/medium.jpg", Size: 200},
-				{URL: "http://example.com/small.jpg", Size: 100},
-			},
 		}
 		ag.On("GetAlbumInfo", ctx, "Test Album", "Test Artist", "mbid-album").Return(expectedInfo, nil)
+		ag.On("GetAlbumImages", ctx, "Test Album", "Test Artist", "mbid-album").Return([]agents.ExternalImage{
+			{URL: "http://example.com/large.jpg", Size: 300},
+			{URL: "http://example.com/medium.jpg", Size: 200},
+			{URL: "http://example.com/small.jpg", Size: 100},
+		}, nil)
 
 		updatedAlbum, err := p.UpdateAlbumInfo(ctx, "al-existing")
 
@@ -74,9 +74,6 @@ var _ = Describe("Provider - UpdateAlbumInfo", func() {
 		Expect(updatedAlbum.ID).To(Equal("al-existing"))
 		Expect(updatedAlbum.ExternalUrl).To(Equal("http://example.com/album"))
 		Expect(updatedAlbum.Description).To(Equal("Album Description"))
-		Expect(updatedAlbum.LargeImageUrl).To(Equal("http://example.com/large.jpg"))
-		Expect(updatedAlbum.MediumImageUrl).To(Equal("http://example.com/medium.jpg"))
-		Expect(updatedAlbum.SmallImageUrl).To(Equal("http://example.com/small.jpg"))
 		Expect(updatedAlbum.ExternalInfoUpdatedAt).NotTo(BeNil())
 		Expect(*updatedAlbum.ExternalInfoUpdatedAt).To(BeTemporally("~", time.Now(), time.Second))
 

core/external/provider_updateartistinfo_test.go

@@ -226,4 +226,88 @@ var _ = Describe("Provider - UpdateArtistInfo", func() {
 		Expect(updatedArtist.ID).To(Equal("ar-agent-fail"))
 		ag.AssertExpectations(GinkgoT())
 	})
+
+	It("matches similar artists by ID first when agent provides IDs", func() {
+		originalArtist := &model.Artist{
+			ID:   "ar-id-match",
+			Name: "ID Match Artist",
+		}
+		similarByID := model.Artist{ID: "ar-similar-by-id", Name: "Similar By ID", MbzArtistID: "mbid-similar"}
+		mockArtistRepo.SetData(model.Artists{*originalArtist, similarByID})
+
+		// Agent returns similar artist with ID (highest priority matching)
+		rawSimilar := []agents.Artist{
+			{ID: "ar-similar-by-id", Name: "Different Name", MBID: "different-mbid"},
+		}
+
+		ag.On("GetArtistMBID", ctx, "ar-id-match", "ID Match Artist").Return("", nil).Once()
+		ag.On("GetArtistImages", ctx, "ar-id-match", "ID Match Artist", mock.Anything).Return(nil, nil).Maybe()
+		ag.On("GetArtistBiography", ctx, "ar-id-match", "ID Match Artist", mock.Anything).Return("", nil).Maybe()
+		ag.On("GetArtistURL", ctx, "ar-id-match", "ID Match Artist", mock.Anything).Return("", nil).Maybe()
+		ag.On("GetSimilarArtists", ctx, "ar-id-match", "ID Match Artist", mock.Anything, 100).Return(rawSimilar, nil).Once()
+
+		updatedArtist, err := p.UpdateArtistInfo(ctx, "ar-id-match", 10, false)
+
+		Expect(err).NotTo(HaveOccurred())
+		Expect(updatedArtist.SimilarArtists).To(HaveLen(1))
+		// Should match by ID, not by name or MBID
+		Expect(updatedArtist.SimilarArtists[0].ID).To(Equal("ar-similar-by-id"))
+		Expect(updatedArtist.SimilarArtists[0].Name).To(Equal("Similar By ID"))
+	})
+
+	It("matches similar artists by MBID when ID is empty", func() {
+		originalArtist := &model.Artist{
+			ID:   "ar-mbid-match",
+			Name: "MBID Match Artist",
+		}
+		similarByMBID := model.Artist{ID: "ar-similar-by-mbid", Name: "Similar By MBID", MbzArtistID: "mbid-similar"}
+		mockArtistRepo.SetData(model.Artists{*originalArtist, similarByMBID})
+
+		// Agent returns similar artist with only MBID (no ID)
+		rawSimilar := []agents.Artist{
+			{Name: "Different Name", MBID: "mbid-similar"},
+		}
+
+		ag.On("GetArtistMBID", ctx, "ar-mbid-match", "MBID Match Artist").Return("", nil).Once()
+		ag.On("GetArtistImages", ctx, "ar-mbid-match", "MBID Match Artist", mock.Anything).Return(nil, nil).Maybe()
+		ag.On("GetArtistBiography", ctx, "ar-mbid-match", "MBID Match Artist", mock.Anything).Return("", nil).Maybe()
+		ag.On("GetArtistURL", ctx, "ar-mbid-match", "MBID Match Artist", mock.Anything).Return("", nil).Maybe()
+		ag.On("GetSimilarArtists", ctx, "ar-mbid-match", "MBID Match Artist", mock.Anything, 100).Return(rawSimilar, nil).Once()
+
+		updatedArtist, err := p.UpdateArtistInfo(ctx, "ar-mbid-match", 10, false)
+
+		Expect(err).NotTo(HaveOccurred())
+		Expect(updatedArtist.SimilarArtists).To(HaveLen(1))
+		// Should match by MBID since ID was empty
+		Expect(updatedArtist.SimilarArtists[0].ID).To(Equal("ar-similar-by-mbid"))
+		Expect(updatedArtist.SimilarArtists[0].Name).To(Equal("Similar By MBID"))
+	})
+
+	It("falls back to name matching when ID and MBID don't match", func() {
+		originalArtist := &model.Artist{
+			ID:   "ar-name-match",
+			Name: "Name Match Artist",
+		}
+		similarByName := model.Artist{ID: "ar-similar-by-name", Name: "Similar By Name"}
+		mockArtistRepo.SetData(model.Artists{*originalArtist, similarByName})
+
+		// Agent returns similar artist with non-matching ID and MBID
+		rawSimilar := []agents.Artist{
+			{ID: "non-existent-id", Name: "Similar By Name", MBID: "non-existent-mbid"},
+		}
+
+		ag.On("GetArtistMBID", ctx, "ar-name-match", "Name Match Artist").Return("", nil).Once()
+		ag.On("GetArtistImages", ctx, "ar-name-match", "Name Match Artist", mock.Anything).Return(nil, nil).Maybe()
+		ag.On("GetArtistBiography", ctx, "ar-name-match", "Name Match Artist", mock.Anything).Return("", nil).Maybe()
+		ag.On("GetArtistURL", ctx, "ar-name-match", "Name Match Artist", mock.Anything).Return("", nil).Maybe()
+		ag.On("GetSimilarArtists", ctx, "ar-name-match", "Name Match Artist", mock.Anything, 100).Return(rawSimilar, nil).Once()
+
+		updatedArtist, err := p.UpdateArtistInfo(ctx, "ar-name-match", 10, false)
+
+		Expect(err).NotTo(HaveOccurred())
+		Expect(updatedArtist.SimilarArtists).To(HaveLen(1))
+		// Should fall back to name matching since ID and MBID didn't match
+		Expect(updatedArtist.SimilarArtists[0].ID).To(Equal("ar-similar-by-name"))
+		Expect(updatedArtist.SimilarArtists[0].Name).To(Equal("Similar By Name"))
+	})
 })

core/ffmpeg/ffmpeg.go

@@ -112,7 +112,7 @@ func (e *ffmpeg) start(ctx context.Context, args []string) (io.ReadCloser, error
 	log.Trace(ctx, "Executing ffmpeg command", "cmd", args)
 	j := &ffCmd{args: args}
 	j.PipeReader, j.out = io.Pipe()
-	err := j.start()
+	err := j.start(ctx)
 	if err != nil {
 		return nil, err
 	}
@@ -127,8 +127,8 @@ type ffCmd struct {
 	cmd  *exec.Cmd
 }
 
-func (j *ffCmd) start() error {
-	cmd := exec.Command(j.args[0], j.args[1:]...) // #nosec
+func (j *ffCmd) start(ctx context.Context) error {
+	cmd := exec.CommandContext(ctx, j.args[0], j.args[1:]...) // #nosec
 	cmd.Stdout = j.out
 	if log.IsGreaterOrEqualTo(log.LevelTrace) {
 		cmd.Stderr = os.Stderr

core/ffmpeg/ffmpeg_test.go

@@ -1,7 +1,11 @@
 package ffmpeg
 
 import (
+	"context"
+	"runtime"
+	sync "sync"
 	"testing"
+	"time"
 
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/tests"
@@ -65,4 +69,98 @@ var _ = Describe("ffmpeg", func() {
 			Expect(args).To(Equal([]string{"/usr/bin/with spaces/ffmpeg.exe", "-i", "one.mp3", "-f", "ffmetadata"}))
 		})
 	})
+
+	Describe("FFmpeg", func() {
+		Context("when FFmpeg is available", func() {
+			var ff FFmpeg
+
+			BeforeEach(func() {
+				ffOnce = sync.Once{}
+				ff = New()
+				// Skip if FFmpeg is not available
+				if !ff.IsAvailable() {
+					Skip("FFmpeg not available on this system")
+				}
+			})
+
+			It("should interrupt transcoding when context is cancelled", func() {
+				ctx, cancel := context.WithTimeout(GinkgoT().Context(), 5*time.Second)
+				defer cancel()
+
+				// Use a command that generates audio indefinitely
+				// -f lavfi uses FFmpeg's built-in audio source
+				// -t 0 means no time limit (runs forever)
+				command := "ffmpeg -f lavfi -i sine=frequency=1000:duration=0 -f mp3 -"
+
+				// The input file is not used here, but we need to provide a valid path to the Transcode function
+				stream, err := ff.Transcode(ctx, command, "tests/fixtures/test.mp3", 128, 0)
+				Expect(err).ToNot(HaveOccurred())
+				defer stream.Close()
+
+				// Read some data first to ensure FFmpeg is running
+				buf := make([]byte, 1024)
+				_, err = stream.Read(buf)
+				Expect(err).ToNot(HaveOccurred())
+
+				// Cancel the context
+				cancel()
+
+				// Next read should fail due to cancelled context
+				_, err = stream.Read(buf)
+				Expect(err).To(HaveOccurred())
+			})
+
+			It("should handle immediate context cancellation", func() {
+				ctx, cancel := context.WithCancel(GinkgoT().Context())
+				cancel() // Cancel immediately
+
+				// This should fail immediately
+				_, err := ff.Transcode(ctx, "ffmpeg -i %s -f mp3 -", "tests/fixtures/test.mp3", 128, 0)
+				Expect(err).To(MatchError(context.Canceled))
+			})
+		})
+
+		Context("with mock process behavior", func() {
+			var longRunningCmd string
+			BeforeEach(func() {
+				// Use a long-running command for testing cancellation
+				switch runtime.GOOS {
+				case "windows":
+					// Use PowerShell's Start-Sleep
+					ffmpegPath = "powershell"
+					longRunningCmd = "powershell -Command Start-Sleep -Seconds 10"
+				default:
+					// Use sleep on Unix-like systems
+					ffmpegPath = "sleep"
+					longRunningCmd = "sleep 10"
+				}
+			})
+
+			It("should terminate the underlying process when context is cancelled", func() {
+				ff := New()
+				ctx, cancel := context.WithTimeout(GinkgoT().Context(), 5*time.Second)
+				defer cancel()
+
+				// Start a process that will run for a while
+				stream, err := ff.Transcode(ctx, longRunningCmd, "tests/fixtures/test.mp3", 0, 0)
+				Expect(err).ToNot(HaveOccurred())
+				defer stream.Close()
+
+				// Give the process time to start
+				time.Sleep(50 * time.Millisecond)
+
+				// Cancel the context
+				cancel()
+
+				// Try to read from the stream, which should fail
+				buf := make([]byte, 100)
+				_, err = stream.Read(buf)
+				Expect(err).To(HaveOccurred(), "Expected stream to be closed due to process termination")
+
+				// Verify the stream is closed by attempting another read
+				_, err = stream.Read(buf)
+				Expect(err).To(HaveOccurred())
+			})
+		})
+	})
 })

core/library.go

@@ -0,0 +1,415 @@
+package core
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/Masterminds/squirrel"
+	"github.com/deluan/rest"
+	"github.com/navidrome/navidrome/core/storage"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/server/events"
+	"github.com/navidrome/navidrome/utils/slice"
+)
+
+// Watcher interface for managing file system watchers
+type Watcher interface {
+	Watch(ctx context.Context, lib *model.Library) error
+	StopWatching(ctx context.Context, libraryID int) error
+}
+
+// Library provides business logic for library management and user-library associations
+type Library interface {
+	GetUserLibraries(ctx context.Context, userID string) (model.Libraries, error)
+	SetUserLibraries(ctx context.Context, userID string, libraryIDs []int) error
+	ValidateLibraryAccess(ctx context.Context, userID string, libraryID int) error
+
+	NewRepository(ctx context.Context) rest.Repository
+}
+
+type libraryService struct {
+	ds            model.DataStore
+	scanner       model.Scanner
+	watcher       Watcher
+	broker        events.Broker
+	pluginManager PluginUnloader
+}
+
+// NewLibrary creates a new Library service
+func NewLibrary(ds model.DataStore, scanner model.Scanner, watcher Watcher, broker events.Broker, pluginManager PluginUnloader) Library {
+	return &libraryService{
+		ds:            ds,
+		scanner:       scanner,
+		watcher:       watcher,
+		broker:        broker,
+		pluginManager: pluginManager,
+	}
+}
+
+// User-library association operations
+
+func (s *libraryService) GetUserLibraries(ctx context.Context, userID string) (model.Libraries, error) {
+	// Verify user exists
+	if _, err := s.ds.User(ctx).Get(userID); err != nil {
+		return nil, err
+	}
+
+	return s.ds.User(ctx).GetUserLibraries(userID)
+}
+
+func (s *libraryService) SetUserLibraries(ctx context.Context, userID string, libraryIDs []int) error {
+	// Verify user exists
+	user, err := s.ds.User(ctx).Get(userID)
+	if err != nil {
+		return err
+	}
+
+	// Admin users get all libraries automatically - don't allow manual assignment
+	if user.IsAdmin {
+		return fmt.Errorf("%w: cannot manually assign libraries to admin users", model.ErrValidation)
+	}
+
+	// Regular users must have at least one library
+	if len(libraryIDs) == 0 {
+		return fmt.Errorf("%w: at least one library must be assigned to non-admin users", model.ErrValidation)
+	}
+
+	// Validate all library IDs exist
+	if len(libraryIDs) > 0 {
+		if err := s.validateLibraryIDs(ctx, libraryIDs); err != nil {
+			return err
+		}
+	}
+
+	// Set user libraries
+	err = s.ds.User(ctx).SetUserLibraries(userID, libraryIDs)
+	if err != nil {
+		return fmt.Errorf("error setting user libraries: %w", err)
+	}
+
+	// Send refresh event to all clients
+	event := &events.RefreshResource{}
+	libIDs := slice.Map(libraryIDs, func(id int) string { return strconv.Itoa(id) })
+	event = event.With("user", userID).With("library", libIDs...)
+	s.broker.SendBroadcastMessage(ctx, event)
+	return nil
+}
+
+func (s *libraryService) ValidateLibraryAccess(ctx context.Context, userID string, libraryID int) error {
+	user, ok := request.UserFrom(ctx)
+	if !ok {
+		return fmt.Errorf("user not found in context")
+	}
+
+	// Admin users have access to all libraries
+	if user.IsAdmin {
+		return nil
+	}
+
+	// Check if user has explicit access to this library
+	libraries, err := s.ds.User(ctx).GetUserLibraries(userID)
+	if err != nil {
+		log.Error(ctx, "Error checking library access", "userID", userID, "libraryID", libraryID, err)
+		return fmt.Errorf("error checking library access: %w", err)
+	}
+
+	for _, lib := range libraries {
+		if lib.ID == libraryID {
+			return nil
+		}
+	}
+
+	return fmt.Errorf("%w: user does not have access to library %d", model.ErrNotAuthorized, libraryID)
+}
+
+// REST repository wrapper
+
+func (s *libraryService) NewRepository(ctx context.Context) rest.Repository {
+	repo := s.ds.Library(ctx)
+	wrapper := &libraryRepositoryWrapper{
+		ctx:               ctx,
+		LibraryRepository: repo,
+		Repository:        repo.(rest.Repository),
+		ds:                s.ds,
+		scanner:           s.scanner,
+		watcher:           s.watcher,
+		broker:            s.broker,
+		pluginManager:     s.pluginManager,
+	}
+	return wrapper
+}
+
+type libraryRepositoryWrapper struct {
+	rest.Repository
+	model.LibraryRepository
+	ctx           context.Context
+	ds            model.DataStore
+	scanner       model.Scanner
+	watcher       Watcher
+	broker        events.Broker
+	pluginManager PluginUnloader
+}
+
+func (r *libraryRepositoryWrapper) Save(entity interface{}) (string, error) {
+	lib := entity.(*model.Library)
+	if err := r.validateLibrary(lib); err != nil {
+		return "", err
+	}
+
+	err := r.LibraryRepository.Put(lib)
+	if err != nil {
+		return "", r.mapError(err)
+	}
+
+	// Start watcher and trigger scan after successful library creation
+	if r.watcher != nil {
+		if err := r.watcher.Watch(r.ctx, lib); err != nil {
+			log.Warn(r.ctx, "Failed to start watcher for new library", "libraryID", lib.ID, "name", lib.Name, "path", lib.Path, err)
+		}
+	}
+
+	if r.scanner != nil {
+		go r.triggerScan(lib, "new")
+	}
+
+	// Send library refresh event to all clients
+	if r.broker != nil {
+		event := &events.RefreshResource{}
+		r.broker.SendBroadcastMessage(r.ctx, event.With("library", strconv.Itoa(lib.ID)))
+		log.Debug(r.ctx, "Library created - sent refresh event", "libraryID", lib.ID, "name", lib.Name)
+	}
+
+	return strconv.Itoa(lib.ID), nil
+}
+
+func (r *libraryRepositoryWrapper) Update(id string, entity interface{}, _ ...string) error {
+	lib := entity.(*model.Library)
+	libID, err := strconv.Atoi(id)
+	if err != nil {
+		return fmt.Errorf("invalid library ID: %s", id)
+	}
+
+	lib.ID = libID
+	if err := r.validateLibrary(lib); err != nil {
+		return err
+	}
+
+	// Get the original library to check if path changed
+	originalLib, err := r.Get(libID)
+	if err != nil {
+		return r.mapError(err)
+	}
+
+	pathChanged := originalLib.Path != lib.Path
+
+	err = r.LibraryRepository.Put(lib)
+	if err != nil {
+		return r.mapError(err)
+	}
+
+	// Restart watcher and trigger scan if path was updated
+	if pathChanged {
+		if r.watcher != nil {
+			if err := r.watcher.Watch(r.ctx, lib); err != nil {
+				log.Warn(r.ctx, "Failed to restart watcher for updated library", "libraryID", lib.ID, "name", lib.Name, "path", lib.Path, err)
+			}
+		}
+
+		if r.scanner != nil {
+			go r.triggerScan(lib, "updated")
+		}
+	}
+
+	// Send library refresh event to all clients
+	if r.broker != nil {
+		event := &events.RefreshResource{}
+		r.broker.SendBroadcastMessage(r.ctx, event.With("library", id))
+		log.Debug(r.ctx, "Library updated - sent refresh event", "libraryID", libID, "name", lib.Name)
+	}
+
+	return nil
+}
+
+func (r *libraryRepositoryWrapper) Delete(id string) error {
+	libID, err := strconv.Atoi(id)
+	if err != nil {
+		return &rest.ValidationError{Errors: map[string]string{
+			"id": "invalid library ID format",
+		}}
+	}
+
+	// Get library info before deletion for logging
+	lib, err := r.Get(libID)
+	if err != nil {
+		return r.mapError(err)
+	}
+
+	err = r.LibraryRepository.Delete(libID)
+	if err != nil {
+		return r.mapError(err)
+	}
+
+	// Stop watcher and trigger scan after successful library deletion to clean up orphaned data
+	if r.watcher != nil {
+		if err := r.watcher.StopWatching(r.ctx, libID); err != nil {
+			log.Warn(r.ctx, "Failed to stop watcher for deleted library", "libraryID", libID, "name", lib.Name, "path", lib.Path, err)
+		}
+	}
+
+	if r.scanner != nil {
+		go r.triggerScan(lib, "deleted")
+	}
+
+	// Send library refresh event to all clients
+	if r.broker != nil {
+		event := &events.RefreshResource{}
+		r.broker.SendBroadcastMessage(r.ctx, event.With("library", id))
+		log.Debug(r.ctx, "Library deleted - sent refresh event", "libraryID", libID, "name", lib.Name)
+	}
+
+	// After successful deletion, check if any plugins were auto-disabled
+	// and need to be unloaded from memory
+	r.pluginManager.UnloadDisabledPlugins(r.ctx)
+
+	return nil
+}
+
+// Helper methods
+
+func (r *libraryRepositoryWrapper) mapError(err error) error {
+	if err == nil {
+		return nil
+	}
+
+	errStr := err.Error()
+
+	// Handle database constraint violations.
+	// TODO: Being tied to react-admin translations is not ideal, but this will probably go away with the new UI/API
+	if strings.Contains(errStr, "UNIQUE constraint failed") {
+		if strings.Contains(errStr, "library.name") {
+			return &rest.ValidationError{Errors: map[string]string{"name": "ra.validation.unique"}}
+		}
+		if strings.Contains(errStr, "library.path") {
+			return &rest.ValidationError{Errors: map[string]string{"path": "ra.validation.unique"}}
+		}
+	}
+
+	switch {
+	case errors.Is(err, model.ErrNotFound):
+		return rest.ErrNotFound
+	case errors.Is(err, model.ErrNotAuthorized):
+		return rest.ErrPermissionDenied
+	default:
+		return err
+	}
+}
+
+func (r *libraryRepositoryWrapper) validateLibrary(library *model.Library) error {
+	validationErrors := make(map[string]string)
+
+	if library.Name == "" {
+		validationErrors["name"] = "ra.validation.required"
+	}
+
+	if library.Path == "" {
+		validationErrors["path"] = "ra.validation.required"
+	} else {
+		// Validate path format and accessibility
+		if err := r.validateLibraryPath(library); err != nil {
+			validationErrors["path"] = err.Error()
+		}
+	}
+
+	if len(validationErrors) > 0 {
+		return &rest.ValidationError{Errors: validationErrors}
+	}
+
+	return nil
+}
+
+func (r *libraryRepositoryWrapper) validateLibraryPath(library *model.Library) error {
+	// Validate path format
+	if !filepath.IsAbs(library.Path) {
+		return fmt.Errorf("library path must be absolute")
+	}
+
+	// Clean the path to normalize it
+	cleanPath := filepath.Clean(library.Path)
+	library.Path = cleanPath
+
+	// Check if path exists and is accessible using storage abstraction
+	fileStore, err := storage.For(library.Path)
+	if err != nil {
+		return fmt.Errorf("invalid storage scheme: %w", err)
+	}
+
+	fsys, err := fileStore.FS()
+	if err != nil {
+		log.Warn(r.ctx, "Error validating library.path", "path", library.Path, err)
+		return fmt.Errorf("resources.library.validation.pathInvalid")
+	}
+
+	// Check if root directory exists
+	info, err := fs.Stat(fsys, ".")
+	if err != nil {
+		// Parse the error message to check for "not a directory"
+		log.Warn(r.ctx, "Error stating library.path", "path", library.Path, err)
+		errStr := err.Error()
+		if strings.Contains(errStr, "not a directory") ||
+			strings.Contains(errStr, "The directory name is invalid.") {
+			return fmt.Errorf("resources.library.validation.pathNotDirectory")
+		} else if os.IsNotExist(err) {
+			return fmt.Errorf("resources.library.validation.pathNotFound")
+		} else if os.IsPermission(err) {
+			return fmt.Errorf("resources.library.validation.pathNotAccessible")
+		} else {
+			return fmt.Errorf("resources.library.validation.pathInvalid")
+		}
+	}
+
+	if !info.IsDir() {
+		return fmt.Errorf("resources.library.validation.pathNotDirectory")
+	}
+
+	return nil
+}
+
+func (s *libraryService) validateLibraryIDs(ctx context.Context, libraryIDs []int) error {
+	if len(libraryIDs) == 0 {
+		return nil
+	}
+
+	// Use CountAll to efficiently validate library IDs exist
+	count, err := s.ds.Library(ctx).CountAll(model.QueryOptions{
+		Filters: squirrel.Eq{"id": libraryIDs},
+	})
+	if err != nil {
+		return fmt.Errorf("error validating library IDs: %w", err)
+	}
+
+	if int(count) != len(libraryIDs) {
+		return fmt.Errorf("%w: one or more library IDs are invalid", model.ErrValidation)
+	}
+
+	return nil
+}
+
+func (r *libraryRepositoryWrapper) triggerScan(lib *model.Library, action string) {
+	log.Info(r.ctx, fmt.Sprintf("Triggering scan for %s library", action), "libraryID", lib.ID, "name", lib.Name, "path", lib.Path)
+	start := time.Now()
+	warnings, err := r.scanner.ScanAll(r.ctx, false) // Quick scan for new library
+	if err != nil {
+		log.Error(r.ctx, fmt.Sprintf("Error scanning %s library", action), "libraryID", lib.ID, "name", lib.Name, err)
+	} else {
+		log.Info(r.ctx, fmt.Sprintf("Scan completed for %s library", action), "libraryID", lib.ID, "name", lib.Name, "warnings", len(warnings), "elapsed", time.Since(start))
+	}
+}

core/library_test.go

@@ -0,0 +1,998 @@
+package core_test
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sync"
+
+	"github.com/deluan/rest"
+	_ "github.com/navidrome/navidrome/adapters/gotaglib" // Register taglib extractor
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/core"
+	_ "github.com/navidrome/navidrome/core/storage/local" // Register local storage
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/server/events"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// These tests require the local storage adapter and the taglib extractor to be registered.
+var _ = Describe("Library Service", func() {
+	var service core.Library
+	var ds *tests.MockDataStore
+	var libraryRepo *tests.MockLibraryRepo
+	var userRepo *tests.MockedUserRepo
+	var ctx context.Context
+	var tempDir string
+	var scanner *tests.MockScanner
+	var watcherManager *mockWatcherManager
+	var broker *mockEventBroker
+	var pluginManager *mockPluginUnloader
+
+	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+
+		ds = &tests.MockDataStore{}
+		libraryRepo = &tests.MockLibraryRepo{}
+		userRepo = tests.CreateMockUserRepo()
+		ds.MockedLibrary = libraryRepo
+		ds.MockedUser = userRepo
+
+		// Create a mock scanner that tracks calls
+		scanner = tests.NewMockScanner()
+		// Create a mock watcher manager
+		watcherManager = &mockWatcherManager{
+			libraryStates: make(map[int]model.Library),
+		}
+		// Create a mock event broker
+		broker = &mockEventBroker{}
+		// Create a mock plugin unloader
+		pluginManager = &mockPluginUnloader{}
+		service = core.NewLibrary(ds, scanner, watcherManager, broker, pluginManager)
+		ctx = context.Background()
+
+		// Create a temporary directory for testing valid paths
+		var err error
+		tempDir, err = os.MkdirTemp("", "navidrome-library-test-")
+		Expect(err).NotTo(HaveOccurred())
+		DeferCleanup(func() {
+			os.RemoveAll(tempDir)
+		})
+	})
+
+	Describe("Library CRUD Operations", func() {
+		var repo rest.Persistable
+
+		BeforeEach(func() {
+			r := service.NewRepository(ctx)
+			repo = r.(rest.Persistable)
+		})
+
+		Describe("Create", func() {
+			It("creates a new library successfully", func() {
+				library := &model.Library{ID: 1, Name: "New Library", Path: tempDir}
+
+				_, err := repo.Save(library)
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(libraryRepo.Data[1].Name).To(Equal("New Library"))
+				Expect(libraryRepo.Data[1].Path).To(Equal(tempDir))
+			})
+
+			It("fails when library name is empty", func() {
+				library := &model.Library{Path: tempDir}
+
+				_, err := repo.Save(library)
+
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("ra.validation.required"))
+			})
+
+			It("fails when library path is empty", func() {
+				library := &model.Library{Name: "Test"}
+
+				_, err := repo.Save(library)
+
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("ra.validation.required"))
+			})
+
+			It("fails when library path is not absolute", func() {
+				library := &model.Library{Name: "Test", Path: "relative/path"}
+
+				_, err := repo.Save(library)
+
+				Expect(err).To(HaveOccurred())
+				var validationErr *rest.ValidationError
+				Expect(errors.As(err, &validationErr)).To(BeTrue())
+				Expect(validationErr.Errors["path"]).To(Equal("library path must be absolute"))
+			})
+
+			Context("Database constraint violations", func() {
+				BeforeEach(func() {
+					// Set up an existing library that will cause constraint violations
+					libraryRepo.SetData(model.Libraries{
+						{ID: 1, Name: "Existing Library", Path: tempDir},
+					})
+				})
+
+				AfterEach(func() {
+					// Reset custom PutFn after each test
+					libraryRepo.PutFn = nil
+				})
+
+				It("handles name uniqueness constraint violation from database", func() {
+					// Create the directory that will be used for the test
+					otherTempDir, err := os.MkdirTemp("", "navidrome-other-")
+					Expect(err).NotTo(HaveOccurred())
+					DeferCleanup(func() { os.RemoveAll(otherTempDir) })
+
+					// Try to create another library with the same name
+					library := &model.Library{ID: 2, Name: "Existing Library", Path: otherTempDir}
+
+					// Mock the repository to return a UNIQUE constraint error
+					libraryRepo.PutFn = func(library *model.Library) error {
+						return errors.New("UNIQUE constraint failed: library.name")
+					}
+
+					_, err = repo.Save(library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors["name"]).To(Equal("ra.validation.unique"))
+				})
+
+				It("handles path uniqueness constraint violation from database", func() {
+					// Try to create another library with the same path
+					library := &model.Library{ID: 2, Name: "Different Library", Path: tempDir}
+
+					// Mock the repository to return a UNIQUE constraint error
+					libraryRepo.PutFn = func(library *model.Library) error {
+						return errors.New("UNIQUE constraint failed: library.path")
+					}
+
+					_, err := repo.Save(library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors["path"]).To(Equal("ra.validation.unique"))
+				})
+			})
+		})
+
+		Describe("Update", func() {
+			BeforeEach(func() {
+				libraryRepo.SetData(model.Libraries{
+					{ID: 1, Name: "Original Library", Path: tempDir},
+				})
+			})
+
+			It("updates an existing library successfully", func() {
+				newTempDir, err := os.MkdirTemp("", "navidrome-library-update-")
+				Expect(err).NotTo(HaveOccurred())
+				DeferCleanup(func() { os.RemoveAll(newTempDir) })
+
+				library := &model.Library{ID: 1, Name: "Updated Library", Path: newTempDir}
+
+				err = repo.Update("1", library)
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(libraryRepo.Data[1].Name).To(Equal("Updated Library"))
+				Expect(libraryRepo.Data[1].Path).To(Equal(newTempDir))
+			})
+
+			It("fails when library doesn't exist", func() {
+				// Create a unique temporary directory to avoid path conflicts
+				uniqueTempDir, err := os.MkdirTemp("", "navidrome-nonexistent-")
+				Expect(err).NotTo(HaveOccurred())
+				DeferCleanup(func() { os.RemoveAll(uniqueTempDir) })
+
+				library := &model.Library{ID: 999, Name: "Non-existent", Path: uniqueTempDir}
+
+				err = repo.Update("999", library)
+
+				Expect(err).To(HaveOccurred())
+				Expect(err).To(Equal(model.ErrNotFound))
+			})
+
+			It("fails when library name is empty", func() {
+				library := &model.Library{ID: 1, Path: tempDir}
+
+				err := repo.Update("1", library)
+
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("ra.validation.required"))
+			})
+
+			It("cleans and normalizes the path on update", func() {
+				unnormalizedPath := tempDir + "//../" + filepath.Base(tempDir)
+				library := &model.Library{ID: 1, Name: "Updated Library", Path: unnormalizedPath}
+
+				err := repo.Update("1", library)
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(libraryRepo.Data[1].Path).To(Equal(filepath.Clean(unnormalizedPath)))
+			})
+
+			It("allows updating library with same name (no change)", func() {
+				// Set up a library
+				libraryRepo.SetData(model.Libraries{
+					{ID: 1, Name: "Test Library", Path: tempDir},
+				})
+
+				// Update the library keeping the same name (should be allowed)
+				library := &model.Library{ID: 1, Name: "Test Library", Path: tempDir}
+
+				err := repo.Update("1", library)
+
+				Expect(err).NotTo(HaveOccurred())
+			})
+
+			It("allows updating library with same path (no change)", func() {
+				// Set up a library
+				libraryRepo.SetData(model.Libraries{
+					{ID: 1, Name: "Test Library", Path: tempDir},
+				})
+
+				// Update the library keeping the same path (should be allowed)
+				library := &model.Library{ID: 1, Name: "Test Library", Path: tempDir}
+
+				err := repo.Update("1", library)
+
+				Expect(err).NotTo(HaveOccurred())
+			})
+
+			Context("Database constraint violations during update", func() {
+				BeforeEach(func() {
+					// Reset any custom PutFn from previous tests
+					libraryRepo.PutFn = nil
+				})
+
+				It("handles name uniqueness constraint violation during update", func() {
+					// Create additional temp directory for the test
+					otherTempDir, err := os.MkdirTemp("", "navidrome-other-")
+					Expect(err).NotTo(HaveOccurred())
+					DeferCleanup(func() { os.RemoveAll(otherTempDir) })
+
+					// Set up two libraries
+					libraryRepo.SetData(model.Libraries{
+						{ID: 1, Name: "Library One", Path: tempDir},
+						{ID: 2, Name: "Library Two", Path: otherTempDir},
+					})
+
+					// Mock database constraint violation
+					libraryRepo.PutFn = func(library *model.Library) error {
+						return errors.New("UNIQUE constraint failed: library.name")
+					}
+
+					// Try to update library 2 to have the same name as library 1
+					library := &model.Library{ID: 2, Name: "Library One", Path: otherTempDir}
+
+					err = repo.Update("2", library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors["name"]).To(Equal("ra.validation.unique"))
+				})
+
+				It("handles path uniqueness constraint violation during update", func() {
+					// Create additional temp directory for the test
+					otherTempDir, err := os.MkdirTemp("", "navidrome-other-")
+					Expect(err).NotTo(HaveOccurred())
+					DeferCleanup(func() { os.RemoveAll(otherTempDir) })
+
+					// Set up two libraries
+					libraryRepo.SetData(model.Libraries{
+						{ID: 1, Name: "Library One", Path: tempDir},
+						{ID: 2, Name: "Library Two", Path: otherTempDir},
+					})
+
+					// Mock database constraint violation
+					libraryRepo.PutFn = func(library *model.Library) error {
+						return errors.New("UNIQUE constraint failed: library.path")
+					}
+
+					// Try to update library 2 to have the same path as library 1
+					library := &model.Library{ID: 2, Name: "Library Two", Path: tempDir}
+
+					err = repo.Update("2", library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors["path"]).To(Equal("ra.validation.unique"))
+				})
+			})
+		})
+
+		Describe("Path Validation", func() {
+			Context("Create operation", func() {
+				It("fails when path is not absolute", func() {
+					library := &model.Library{Name: "Test", Path: "relative/path"}
+
+					_, err := repo.Save(library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors["path"]).To(Equal("library path must be absolute"))
+				})
+
+				It("fails when path does not exist", func() {
+					nonExistentPath := filepath.Join(tempDir, "nonexistent")
+					library := &model.Library{Name: "Test", Path: nonExistentPath}
+
+					_, err := repo.Save(library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors["path"]).To(Equal("resources.library.validation.pathInvalid"))
+				})
+
+				It("fails when path is a file instead of directory", func() {
+					testFile := filepath.Join(tempDir, "testfile.txt")
+					err := os.WriteFile(testFile, []byte("test"), 0600)
+					Expect(err).NotTo(HaveOccurred())
+
+					library := &model.Library{Name: "Test", Path: testFile}
+
+					_, err = repo.Save(library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors["path"]).To(Equal("resources.library.validation.pathNotDirectory"))
+				})
+
+				It("fails when path is not accessible due to permissions", func() {
+					Skip("Permission tests are environment-dependent and may fail in CI")
+					// This test is skipped because creating a directory with no read permissions
+					// is complex and may not work consistently across different environments
+				})
+
+				It("handles multiple validation errors", func() {
+					library := &model.Library{Name: "", Path: "relative/path"}
+
+					_, err := repo.Save(library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors).To(HaveKey("name"))
+					Expect(validationErr.Errors).To(HaveKey("path"))
+					Expect(validationErr.Errors["name"]).To(Equal("ra.validation.required"))
+					Expect(validationErr.Errors["path"]).To(Equal("library path must be absolute"))
+				})
+			})
+
+			Context("Update operation", func() {
+				BeforeEach(func() {
+					libraryRepo.SetData(model.Libraries{
+						{ID: 1, Name: "Test Library", Path: tempDir},
+					})
+				})
+
+				It("fails when updated path is not absolute", func() {
+					library := &model.Library{ID: 1, Name: "Test", Path: "relative/path"}
+
+					err := repo.Update("1", library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors["path"]).To(Equal("library path must be absolute"))
+				})
+
+				It("allows updating library with same name (no change)", func() {
+					// Set up a library
+					libraryRepo.SetData(model.Libraries{
+						{ID: 1, Name: "Test Library", Path: tempDir},
+					})
+
+					// Update the library keeping the same name (should be allowed)
+					library := &model.Library{ID: 1, Name: "Test Library", Path: tempDir}
+
+					err := repo.Update("1", library)
+
+					Expect(err).NotTo(HaveOccurred())
+				})
+
+				It("fails when updated path does not exist", func() {
+					nonExistentPath := filepath.Join(tempDir, "nonexistent")
+					library := &model.Library{ID: 1, Name: "Test", Path: nonExistentPath}
+
+					err := repo.Update("1", library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors["path"]).To(Equal("resources.library.validation.pathInvalid"))
+				})
+
+				It("fails when updated path is a file instead of directory", func() {
+					testFile := filepath.Join(tempDir, "updatefile.txt")
+					err := os.WriteFile(testFile, []byte("test"), 0600)
+					Expect(err).NotTo(HaveOccurred())
+
+					library := &model.Library{ID: 1, Name: "Test", Path: testFile}
+
+					err = repo.Update("1", library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors["path"]).To(Equal("resources.library.validation.pathNotDirectory"))
+				})
+
+				It("handles multiple validation errors on update", func() {
+					// Try to update with empty name and invalid path
+					library := &model.Library{ID: 1, Name: "", Path: "relative/path"}
+
+					err := repo.Update("1", library)
+
+					Expect(err).To(HaveOccurred())
+					var validationErr *rest.ValidationError
+					Expect(errors.As(err, &validationErr)).To(BeTrue())
+					Expect(validationErr.Errors).To(HaveKey("name"))
+					Expect(validationErr.Errors).To(HaveKey("path"))
+					Expect(validationErr.Errors["name"]).To(Equal("ra.validation.required"))
+					Expect(validationErr.Errors["path"]).To(Equal("library path must be absolute"))
+				})
+			})
+		})
+
+		Describe("Delete", func() {
+			BeforeEach(func() {
+				libraryRepo.SetData(model.Libraries{
+					{ID: 1, Name: "Library to Delete", Path: tempDir},
+				})
+			})
+
+			It("deletes an existing library successfully", func() {
+				err := repo.Delete("1")
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(libraryRepo.Data).To(HaveLen(0))
+			})
+
+			It("fails when library doesn't exist", func() {
+				err := repo.Delete("999")
+
+				Expect(err).To(HaveOccurred())
+				Expect(err).To(Equal(model.ErrNotFound))
+			})
+		})
+	})
+
+	Describe("User-Library Association Operations", func() {
+		var regularUser, adminUser *model.User
+
+		BeforeEach(func() {
+			regularUser = &model.User{ID: "user1", UserName: "regular", IsAdmin: false}
+			adminUser = &model.User{ID: "admin1", UserName: "admin", IsAdmin: true}
+
+			userRepo.Data = map[string]*model.User{
+				"regular": regularUser,
+				"admin":   adminUser,
+			}
+			libraryRepo.SetData(model.Libraries{
+				{ID: 1, Name: "Library 1", Path: "/music1"},
+				{ID: 2, Name: "Library 2", Path: "/music2"},
+				{ID: 3, Name: "Library 3", Path: "/music3"},
+			})
+		})
+
+		Describe("GetUserLibraries", func() {
+			It("returns user's libraries", func() {
+				userRepo.UserLibraries = map[string][]int{
+					"user1": {1},
+				}
+
+				result, err := service.GetUserLibraries(ctx, "user1")
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(result).To(HaveLen(1))
+				Expect(result[0].ID).To(Equal(1))
+			})
+
+			It("fails when user doesn't exist", func() {
+				_, err := service.GetUserLibraries(ctx, "nonexistent")
+
+				Expect(err).To(HaveOccurred())
+				Expect(err).To(Equal(model.ErrNotFound))
+			})
+		})
+
+		Describe("SetUserLibraries", func() {
+			It("sets libraries for regular user successfully", func() {
+				err := service.SetUserLibraries(ctx, "user1", []int{1, 2})
+
+				Expect(err).NotTo(HaveOccurred())
+				libraries := userRepo.UserLibraries["user1"]
+				Expect(libraries).To(HaveLen(2))
+			})
+
+			It("fails when user doesn't exist", func() {
+				err := service.SetUserLibraries(ctx, "nonexistent", []int{1})
+
+				Expect(err).To(HaveOccurred())
+				Expect(err).To(Equal(model.ErrNotFound))
+			})
+
+			It("fails when trying to set libraries for admin user", func() {
+				err := service.SetUserLibraries(ctx, "admin1", []int{1})
+
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("cannot manually assign libraries to admin users"))
+			})
+
+			It("fails when no libraries provided for regular user", func() {
+				err := service.SetUserLibraries(ctx, "user1", []int{})
+
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("at least one library must be assigned to non-admin users"))
+			})
+
+			It("fails when library doesn't exist", func() {
+				err := service.SetUserLibraries(ctx, "user1", []int{999})
+
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("one or more library IDs are invalid"))
+			})
+
+			It("fails when some libraries don't exist", func() {
+				err := service.SetUserLibraries(ctx, "user1", []int{1, 999, 2})
+
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("one or more library IDs are invalid"))
+			})
+		})
+
+		Describe("ValidateLibraryAccess", func() {
+			Context("admin user", func() {
+				BeforeEach(func() {
+					ctx = request.WithUser(ctx, *adminUser)
+				})
+
+				It("allows access to any library", func() {
+					err := service.ValidateLibraryAccess(ctx, "admin1", 1)
+
+					Expect(err).NotTo(HaveOccurred())
+				})
+			})
+
+			Context("regular user", func() {
+				BeforeEach(func() {
+					ctx = request.WithUser(ctx, *regularUser)
+					userRepo.UserLibraries = map[string][]int{
+						"user1": {1},
+					}
+				})
+
+				It("allows access to user's libraries", func() {
+					err := service.ValidateLibraryAccess(ctx, "user1", 1)
+
+					Expect(err).NotTo(HaveOccurred())
+				})
+
+				It("denies access to libraries user doesn't have", func() {
+					err := service.ValidateLibraryAccess(ctx, "user1", 2)
+
+					Expect(err).To(HaveOccurred())
+					Expect(err.Error()).To(ContainSubstring("user does not have access to library 2"))
+				})
+			})
+
+			Context("no user in context", func() {
+				It("fails with user not found error", func() {
+					err := service.ValidateLibraryAccess(ctx, "user1", 1)
+
+					Expect(err).To(HaveOccurred())
+					Expect(err.Error()).To(ContainSubstring("user not found in context"))
+				})
+			})
+		})
+	})
+
+	Describe("Scan Triggering", func() {
+		var repo rest.Persistable
+
+		BeforeEach(func() {
+			r := service.NewRepository(ctx)
+			repo = r.(rest.Persistable)
+		})
+
+		It("triggers scan when creating a new library", func() {
+			library := &model.Library{ID: 1, Name: "New Library", Path: tempDir}
+
+			_, err := repo.Save(library)
+			Expect(err).NotTo(HaveOccurred())
+
+			// Wait briefly for the goroutine to complete
+			Eventually(func() int {
+				return scanner.GetScanAllCallCount()
+			}, "1s", "10ms").Should(Equal(1))
+
+			// Verify scan was called with correct parameters
+			calls := scanner.GetScanAllCalls()
+			Expect(calls[0].FullScan).To(BeFalse()) // Should be quick scan
+		})
+
+		It("triggers scan when updating library path", func() {
+			// First create a library
+			libraryRepo.SetData(model.Libraries{
+				{ID: 1, Name: "Original Library", Path: tempDir},
+			})
+
+			// Create a new temporary directory for the update
+			newTempDir, err := os.MkdirTemp("", "navidrome-library-update-")
+			Expect(err).NotTo(HaveOccurred())
+			DeferCleanup(func() { os.RemoveAll(newTempDir) })
+
+			// Update the library with a new path
+			library := &model.Library{ID: 1, Name: "Updated Library", Path: newTempDir}
+			err = repo.Update("1", library)
+			Expect(err).NotTo(HaveOccurred())
+
+			// Wait briefly for the goroutine to complete
+			Eventually(func() int {
+				return scanner.GetScanAllCallCount()
+			}, "1s", "10ms").Should(Equal(1))
+
+			// Verify scan was called with correct parameters
+			calls := scanner.GetScanAllCalls()
+			Expect(calls[0].FullScan).To(BeFalse()) // Should be quick scan
+		})
+
+		It("does not trigger scan when updating library without path change", func() {
+			// First create a library
+			libraryRepo.SetData(model.Libraries{
+				{ID: 1, Name: "Original Library", Path: tempDir},
+			})
+
+			// Update the library name only (same path)
+			library := &model.Library{ID: 1, Name: "Updated Name", Path: tempDir}
+			err := repo.Update("1", library)
+			Expect(err).NotTo(HaveOccurred())
+
+			// Wait a bit to ensure no scan was triggered
+			Consistently(func() int {
+				return scanner.GetScanAllCallCount()
+			}, "100ms", "10ms").Should(Equal(0))
+		})
+
+		It("does not trigger scan when library creation fails", func() {
+			// Try to create library with invalid data (empty name)
+			library := &model.Library{Path: tempDir}
+
+			_, err := repo.Save(library)
+			Expect(err).To(HaveOccurred())
+
+			// Ensure no scan was triggered since creation failed
+			Consistently(func() int {
+				return scanner.GetScanAllCallCount()
+			}, "100ms", "10ms").Should(Equal(0))
+		})
+
+		It("does not trigger scan when library update fails", func() {
+			// First create a library
+			libraryRepo.SetData(model.Libraries{
+				{ID: 1, Name: "Original Library", Path: tempDir},
+			})
+
+			// Try to update with invalid data (empty name)
+			library := &model.Library{ID: 1, Name: "", Path: tempDir}
+			err := repo.Update("1", library)
+			Expect(err).To(HaveOccurred())
+
+			// Ensure no scan was triggered since update failed
+			Consistently(func() int {
+				return scanner.GetScanAllCallCount()
+			}, "100ms", "10ms").Should(Equal(0))
+		})
+
+		It("triggers scan when deleting a library", func() {
+			// First create a library
+			libraryRepo.SetData(model.Libraries{
+				{ID: 1, Name: "Library to Delete", Path: tempDir},
+			})
+
+			// Delete the library
+			err := repo.Delete("1")
+			Expect(err).NotTo(HaveOccurred())
+
+			// Wait briefly for the goroutine to complete
+			Eventually(func() int {
+				return scanner.GetScanAllCallCount()
+			}, "1s", "10ms").Should(Equal(1))
+
+			// Verify scan was called with correct parameters
+			calls := scanner.GetScanAllCalls()
+			Expect(calls[0].FullScan).To(BeFalse()) // Should be quick scan
+		})
+
+		It("does not trigger scan when library deletion fails", func() {
+			// Try to delete a non-existent library
+			err := repo.Delete("999")
+			Expect(err).To(HaveOccurred())
+
+			// Ensure no scan was triggered since deletion failed
+			Consistently(func() int {
+				return scanner.GetScanAllCallCount()
+			}, "100ms", "10ms").Should(Equal(0))
+		})
+
+		Context("Watcher Integration", func() {
+			It("starts watcher when creating a new library", func() {
+				library := &model.Library{ID: 1, Name: "New Library", Path: tempDir}
+
+				_, err := repo.Save(library)
+				Expect(err).NotTo(HaveOccurred())
+
+				// Verify watcher was started
+				Eventually(func() int {
+					return watcherManager.lenStarted()
+				}, "1s", "10ms").Should(Equal(1))
+
+				Expect(watcherManager.StartedWatchers[0].ID).To(Equal(1))
+				Expect(watcherManager.StartedWatchers[0].Name).To(Equal("New Library"))
+				Expect(watcherManager.StartedWatchers[0].Path).To(Equal(tempDir))
+			})
+
+			It("restarts watcher when library path is updated", func() {
+				// First create a library
+				libraryRepo.SetData(model.Libraries{
+					{ID: 1, Name: "Original Library", Path: tempDir},
+				})
+
+				// Simulate that this library already has a watcher
+				watcherManager.simulateExistingLibrary(model.Library{ID: 1, Name: "Original Library", Path: tempDir})
+
+				// Create a new temp directory for the update
+				newTempDir, err := os.MkdirTemp("", "navidrome-library-update-")
+				Expect(err).NotTo(HaveOccurred())
+				DeferCleanup(func() { os.RemoveAll(newTempDir) })
+
+				// Update library with new path
+				library := &model.Library{ID: 1, Name: "Updated Library", Path: newTempDir}
+				err = repo.Update("1", library)
+				Expect(err).NotTo(HaveOccurred())
+
+				// Verify watcher was restarted
+				Eventually(func() int {
+					return watcherManager.lenRestarted()
+				}, "1s", "10ms").Should(Equal(1))
+
+				Expect(watcherManager.RestartedWatchers[0].ID).To(Equal(1))
+				Expect(watcherManager.RestartedWatchers[0].Path).To(Equal(newTempDir))
+			})
+
+			It("does not restart watcher when only library name is updated", func() {
+				// First create a library
+				libraryRepo.SetData(model.Libraries{
+					{ID: 1, Name: "Original Library", Path: tempDir},
+				})
+
+				// Update library with same path but different name
+				library := &model.Library{ID: 1, Name: "Updated Name", Path: tempDir}
+				err := repo.Update("1", library)
+				Expect(err).NotTo(HaveOccurred())
+
+				// Verify watcher was NOT restarted (since path didn't change)
+				Consistently(func() int {
+					return watcherManager.lenRestarted()
+				}, "100ms", "10ms").Should(Equal(0))
+			})
+
+			It("stops watcher when library is deleted", func() {
+				// Set up a library
+				libraryRepo.SetData(model.Libraries{
+					{ID: 1, Name: "Test Library", Path: tempDir},
+				})
+
+				err := repo.Delete("1")
+				Expect(err).NotTo(HaveOccurred())
+
+				// Verify watcher was stopped
+				Eventually(func() int {
+					return watcherManager.lenStopped()
+				}, "1s", "10ms").Should(Equal(1))
+
+				Expect(watcherManager.StoppedWatchers[0]).To(Equal(1))
+			})
+
+			It("does not stop watcher when library deletion fails", func() {
+				// Set up a library
+				libraryRepo.SetData(model.Libraries{
+					{ID: 1, Name: "Test Library", Path: tempDir},
+				})
+
+				// Mock deletion to fail by trying to delete non-existent library
+				err := repo.Delete("999")
+				Expect(err).To(HaveOccurred())
+
+				// Verify watcher was NOT stopped since deletion failed
+				Consistently(func() int {
+					return watcherManager.lenStopped()
+				}, "100ms", "10ms").Should(Equal(0))
+			})
+		})
+	})
+
+	Describe("Event Broadcasting", func() {
+		var repo rest.Persistable
+
+		BeforeEach(func() {
+			r := service.NewRepository(ctx)
+			repo = r.(rest.Persistable)
+			// Clear any events from broker
+			broker.Events = []events.Event{}
+		})
+
+		It("sends refresh event when creating a library", func() {
+			library := &model.Library{ID: 1, Name: "New Library", Path: tempDir}
+
+			_, err := repo.Save(library)
+
+			Expect(err).NotTo(HaveOccurred())
+			Expect(broker.Events).To(HaveLen(1))
+		})
+
+		It("sends refresh event when updating a library", func() {
+			// First create a library
+			libraryRepo.SetData(model.Libraries{
+				{ID: 1, Name: "Original Library", Path: tempDir},
+			})
+
+			library := &model.Library{ID: 1, Name: "Updated Library", Path: tempDir}
+			err := repo.Update("1", library)
+
+			Expect(err).NotTo(HaveOccurred())
+			Expect(broker.Events).To(HaveLen(1))
+		})
+
+		It("sends refresh event when deleting a library", func() {
+			// First create a library
+			libraryRepo.SetData(model.Libraries{
+				{ID: 2, Name: "Library to Delete", Path: tempDir},
+			})
+
+			err := repo.Delete("2")
+
+			Expect(err).NotTo(HaveOccurred())
+			Expect(broker.Events).To(HaveLen(1))
+		})
+	})
+
+	Describe("Plugin Manager Integration", func() {
+		var repo rest.Persistable
+
+		BeforeEach(func() {
+			// Reset the call count for each test
+			pluginManager.unloadCalls = 0
+			r := service.NewRepository(ctx)
+			repo = r.(rest.Persistable)
+		})
+
+		It("calls UnloadDisabledPlugins after successful library deletion", func() {
+			libraryRepo.SetData(model.Libraries{
+				{ID: 2, Name: "Library to Delete", Path: tempDir},
+			})
+
+			err := repo.Delete("2")
+			Expect(err).NotTo(HaveOccurred())
+			Expect(pluginManager.unloadCalls).To(Equal(1))
+		})
+
+		It("does not call UnloadDisabledPlugins when library deletion fails", func() {
+			// Try to delete non-existent library
+			err := repo.Delete("999")
+			Expect(err).To(HaveOccurred())
+			Expect(pluginManager.unloadCalls).To(Equal(0))
+		})
+	})
+})
+
+// mockPluginUnloader is a simple mock for testing UnloadDisabledPlugins calls
+type mockPluginUnloader struct {
+	unloadCalls int
+}
+
+func (m *mockPluginUnloader) UnloadDisabledPlugins(ctx context.Context) {
+	m.unloadCalls++
+}
+
+// mockWatcherManager provides a simple mock implementation of core.Watcher for testing
+type mockWatcherManager struct {
+	StartedWatchers   []model.Library
+	StoppedWatchers   []int
+	RestartedWatchers []model.Library
+	libraryStates     map[int]model.Library // Track which libraries we know about
+	mu                sync.RWMutex
+}
+
+func (m *mockWatcherManager) Watch(ctx context.Context, lib *model.Library) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	// Check if we already know about this library ID
+	if _, exists := m.libraryStates[lib.ID]; exists {
+		// This is a restart - the library already existed
+		// Update our tracking and record the restart
+		for i, startedLib := range m.StartedWatchers {
+			if startedLib.ID == lib.ID {
+				m.StartedWatchers[i] = *lib
+				break
+			}
+		}
+		m.RestartedWatchers = append(m.RestartedWatchers, *lib)
+		m.libraryStates[lib.ID] = *lib
+		return nil
+	}
+
+	// This is a new library - first time we're seeing it
+	m.StartedWatchers = append(m.StartedWatchers, *lib)
+	m.libraryStates[lib.ID] = *lib
+	return nil
+}
+
+func (m *mockWatcherManager) StopWatching(ctx context.Context, libraryID int) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.StoppedWatchers = append(m.StoppedWatchers, libraryID)
+	return nil
+}
+
+func (m *mockWatcherManager) lenStarted() int {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return len(m.StartedWatchers)
+}
+
+func (m *mockWatcherManager) lenStopped() int {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return len(m.StoppedWatchers)
+}
+
+func (m *mockWatcherManager) lenRestarted() int {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return len(m.RestartedWatchers)
+}
+
+// simulateExistingLibrary simulates the scenario where a library already exists
+// and has a watcher running (used by tests to set up the initial state)
+func (m *mockWatcherManager) simulateExistingLibrary(lib model.Library) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.libraryStates[lib.ID] = lib
+}
+
+// mockEventBroker provides a mock implementation of events.Broker for testing
+type mockEventBroker struct {
+	http.Handler
+	Events []events.Event
+	mu     sync.RWMutex
+}
+
+func (m *mockEventBroker) SendMessage(ctx context.Context, event events.Event) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.Events = append(m.Events, event)
+}
+
+func (m *mockEventBroker) SendBroadcastMessage(ctx context.Context, event events.Event) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.Events = append(m.Events, event)
+}

core/lyrics/sources.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils/ioutils"
 )
 
 func fromEmbedded(ctx context.Context, mf *model.MediaFile) (model.LyricList, error) {
@@ -27,8 +28,7 @@ func fromExternalFile(ctx context.Context, mf *model.MediaFile, suffix string) (
 
 	externalLyric := basePath[0:len(basePath)-len(ext)] + suffix
 
-	contents, err := os.ReadFile(externalLyric)
-
+	contents, err := ioutils.UTF8ReadFile(externalLyric)
 	if errors.Is(err, os.ErrNotExist) {
 		log.Trace(ctx, "no lyrics found at path", "path", externalLyric)
 		return nil, nil

core/lyrics/sources_test.go

@@ -108,5 +108,39 @@ var _ = Describe("sources", func() {
 				},
 			}))
 		})
+
+		It("should handle LRC files with UTF-8 BOM marker (issue #4631)", func() {
+			// The function looks for <basePath-without-ext><suffix>, so we need to pass
+			// a MediaFile with .mp3 path and look for .lrc suffix
+			mf := model.MediaFile{Path: "tests/fixtures/bom-test.mp3"}
+			lyrics, err := fromExternalFile(ctx, &mf, ".lrc")
+
+			Expect(err).To(BeNil())
+			Expect(lyrics).ToNot(BeNil())
+			Expect(lyrics).To(HaveLen(1))
+
+			// The critical assertion: even with BOM, synced should be true
+			Expect(lyrics[0].Synced).To(BeTrue(), "Lyrics with BOM marker should be recognized as synced")
+			Expect(lyrics[0].Line).To(HaveLen(1))
+			Expect(lyrics[0].Line[0].Start).To(Equal(gg.P(int64(0))))
+			Expect(lyrics[0].Line[0].Value).To(ContainSubstring("作曲"))
+		})
+
+		It("should handle UTF-16 LE encoded LRC files", func() {
+			mf := model.MediaFile{Path: "tests/fixtures/bom-utf16-test.mp3"}
+			lyrics, err := fromExternalFile(ctx, &mf, ".lrc")
+
+			Expect(err).To(BeNil())
+			Expect(lyrics).ToNot(BeNil())
+			Expect(lyrics).To(HaveLen(1))
+
+			// UTF-16 should be properly converted to UTF-8
+			Expect(lyrics[0].Synced).To(BeTrue(), "UTF-16 encoded lyrics should be recognized as synced")
+			Expect(lyrics[0].Line).To(HaveLen(2))
+			Expect(lyrics[0].Line[0].Start).To(Equal(gg.P(int64(18800))))
+			Expect(lyrics[0].Line[0].Value).To(Equal("We're no strangers to love"))
+			Expect(lyrics[0].Line[1].Start).To(Equal(gg.P(int64(22801))))
+			Expect(lyrics[0].Line[1].Value).To(Equal("You know the rules and so do I"))
+		})
 	})
 })

core/maintenance.go

@@ -0,0 +1,226 @@
+package core
+
+import (
+	"context"
+	"fmt"
+	"slices"
+	"sync"
+	"time"
+
+	"github.com/Masterminds/squirrel"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/utils/slice"
+)
+
+type Maintenance interface {
+	// DeleteMissingFiles deletes specific missing files by their IDs
+	DeleteMissingFiles(ctx context.Context, ids []string) error
+	// DeleteAllMissingFiles deletes all files marked as missing
+	DeleteAllMissingFiles(ctx context.Context) error
+}
+
+type maintenanceService struct {
+	ds model.DataStore
+	wg sync.WaitGroup
+}
+
+func NewMaintenance(ds model.DataStore) Maintenance {
+	return &maintenanceService{
+		ds: ds,
+	}
+}
+
+func (s *maintenanceService) DeleteMissingFiles(ctx context.Context, ids []string) error {
+	return s.deleteMissing(ctx, ids)
+}
+
+func (s *maintenanceService) DeleteAllMissingFiles(ctx context.Context) error {
+	return s.deleteMissing(ctx, nil)
+}
+
+// deleteMissing handles the deletion of missing files and triggers necessary cleanup operations
+func (s *maintenanceService) deleteMissing(ctx context.Context, ids []string) error {
+	// Track affected album IDs before deletion for refresh
+	affectedAlbumIDs, err := s.getAffectedAlbumIDs(ctx, ids)
+	if err != nil {
+		log.Warn(ctx, "Error tracking affected albums for refresh", err)
+		// Don't fail the operation, just log the warning
+	}
+
+	// Delete missing files within a transaction
+	err = s.ds.WithTx(func(tx model.DataStore) error {
+		if len(ids) == 0 {
+			_, err := tx.MediaFile(ctx).DeleteAllMissing()
+			return err
+		}
+		return tx.MediaFile(ctx).DeleteMissing(ids)
+	})
+	if err != nil {
+		log.Error(ctx, "Error deleting missing tracks from DB", "ids", ids, err)
+		return err
+	}
+
+	// Run garbage collection to clean up orphaned records
+	if err := s.ds.GC(ctx); err != nil {
+		log.Error(ctx, "Error running GC after deleting missing tracks", err)
+		return err
+	}
+
+	// Refresh statistics in background
+	s.refreshStatsAsync(ctx, affectedAlbumIDs)
+
+	return nil
+}
+
+// refreshAlbums recalculates album attributes (size, duration, song count, etc.) from media files.
+// It uses batch queries to minimize database round-trips for efficiency.
+func (s *maintenanceService) refreshAlbums(ctx context.Context, albumIDs []string) error {
+	if len(albumIDs) == 0 {
+		return nil
+	}
+
+	log.Debug(ctx, "Refreshing albums", "count", len(albumIDs))
+
+	// Process in chunks to avoid query size limits
+	const chunkSize = 100
+	for chunk := range slice.CollectChunks(slices.Values(albumIDs), chunkSize) {
+		if err := s.refreshAlbumChunk(ctx, chunk); err != nil {
+			return fmt.Errorf("refreshing album chunk: %w", err)
+		}
+	}
+
+	log.Debug(ctx, "Successfully refreshed albums", "count", len(albumIDs))
+	return nil
+}
+
+// refreshAlbumChunk processes a single chunk of album IDs
+func (s *maintenanceService) refreshAlbumChunk(ctx context.Context, albumIDs []string) error {
+	albumRepo := s.ds.Album(ctx)
+	mfRepo := s.ds.MediaFile(ctx)
+
+	// Batch load existing albums
+	albums, err := albumRepo.GetAll(model.QueryOptions{
+		Filters: squirrel.Eq{"album.id": albumIDs},
+	})
+	if err != nil {
+		return fmt.Errorf("loading albums: %w", err)
+	}
+
+	// Create a map for quick lookup
+	albumMap := make(map[string]*model.Album, len(albums))
+	for i := range albums {
+		albumMap[albums[i].ID] = &albums[i]
+	}
+
+	// Batch load all media files for these albums
+	mediaFiles, err := mfRepo.GetAll(model.QueryOptions{
+		Filters: squirrel.Eq{"album_id": albumIDs},
+		Sort:    "album_id, path",
+	})
+	if err != nil {
+		return fmt.Errorf("loading media files: %w", err)
+	}
+
+	// Group media files by album ID
+	filesByAlbum := make(map[string]model.MediaFiles)
+	for i := range mediaFiles {
+		albumID := mediaFiles[i].AlbumID
+		filesByAlbum[albumID] = append(filesByAlbum[albumID], mediaFiles[i])
+	}
+
+	// Recalculate each album from its media files
+	for albumID, oldAlbum := range albumMap {
+		mfs, hasTracks := filesByAlbum[albumID]
+		if !hasTracks {
+			// Album has no tracks anymore, skip (will be cleaned up by GC)
+			log.Debug(ctx, "Skipping album with no tracks", "albumID", albumID)
+			continue
+		}
+
+		// Recalculate album from media files
+		newAlbum := mfs.ToAlbum()
+
+		// Only update if something changed (avoid unnecessary writes)
+		if !oldAlbum.Equals(newAlbum) {
+			// Preserve original timestamps
+			newAlbum.UpdatedAt = time.Now()
+			newAlbum.CreatedAt = oldAlbum.CreatedAt
+
+			if err := albumRepo.Put(&newAlbum); err != nil {
+				log.Error(ctx, "Error updating album during refresh", "albumID", albumID, err)
+				// Continue with other albums instead of failing entirely
+				continue
+			}
+			log.Trace(ctx, "Refreshed album", "albumID", albumID, "name", newAlbum.Name)
+		}
+	}
+
+	return nil
+}
+
+// getAffectedAlbumIDs returns distinct album IDs from missing media files
+func (s *maintenanceService) getAffectedAlbumIDs(ctx context.Context, ids []string) ([]string, error) {
+	var filters squirrel.Sqlizer = squirrel.Eq{"missing": true}
+	if len(ids) > 0 {
+		filters = squirrel.And{
+			squirrel.Eq{"missing": true},
+			squirrel.Eq{"media_file.id": ids},
+		}
+	}
+
+	mfs, err := s.ds.MediaFile(ctx).GetAll(model.QueryOptions{
+		Filters: filters,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	// Extract unique album IDs
+	albumIDMap := make(map[string]struct{}, len(mfs))
+	for _, mf := range mfs {
+		if mf.AlbumID != "" {
+			albumIDMap[mf.AlbumID] = struct{}{}
+		}
+	}
+
+	albumIDs := make([]string, 0, len(albumIDMap))
+	for id := range albumIDMap {
+		albumIDs = append(albumIDs, id)
+	}
+
+	return albumIDs, nil
+}
+
+// refreshStatsAsync refreshes artist and album statistics in background goroutines
+func (s *maintenanceService) refreshStatsAsync(ctx context.Context, affectedAlbumIDs []string) {
+	// Refresh artist stats in background
+	s.wg.Add(1)
+	go func() {
+		defer s.wg.Done()
+		bgCtx := request.AddValues(context.Background(), ctx)
+		if _, err := s.ds.Artist(bgCtx).RefreshStats(true); err != nil {
+			log.Error(bgCtx, "Error refreshing artist stats after deleting missing files", err)
+		} else {
+			log.Debug(bgCtx, "Successfully refreshed artist stats after deleting missing files")
+		}
+
+		// Refresh album stats in background if we have affected albums
+		if len(affectedAlbumIDs) > 0 {
+			if err := s.refreshAlbums(bgCtx, affectedAlbumIDs); err != nil {
+				log.Error(bgCtx, "Error refreshing album stats after deleting missing files", err)
+			} else {
+				log.Debug(bgCtx, "Successfully refreshed album stats after deleting missing files", "count", len(affectedAlbumIDs))
+			}
+		}
+	}()
+}
+
+// Wait waits for all background goroutines to complete.
+// WARNING: This method is ONLY for testing. Never call this in production code.
+// Calling Wait() in production will block until ALL background operations complete
+// and may cause race conditions with new operations starting.
+func (s *maintenanceService) wait() {
+	s.wg.Wait()
+}