yellowjacket/.planning/REQUIREMENTS.md

Requirements: YellowJacket

Defined: 2026-03-06 Core Value: The music player works reliably and feels solid — every interaction is correct, responsive, and trustworthy.

v1.1 Requirements

Requirements for v1.1 Multi-Library Support milestone. Each maps to roadmap phases.

Scan Cancellation (Phase 9 — Complete)

• SCAN-01: User can cancel an in-progress library scan via a cancel button
• SCAN-02: Cancelled scan stops gracefully without corrupting the database
• SCAN-03: User can pause a library scan and resume it without re-scanning processed files

Keyboard Shortcuts (Phase 9 — Complete)

• KEY-01: Default keybindings work out of box (play/pause, next/prev, volume, search focus, queue toggle, shuffle, repeat)
• KEY-02: User can customize all keyboard shortcuts via a visual settings UI
• KEY-03: Shortcut conflicts are detected and warned about when rebinding
• KEY-04: Shortcuts are scoped — different bindings apply based on focused component (track list vs player vs global)
• KEY-05: Shortcuts are disabled when text input has focus (except Escape to blur)

Library Management

• LIB-01: User can add a new library directory via a folder picker dialog
• LIB-02: User can rename a library (display name)
• LIB-03: User can remove a library — tracks are deleted from DB, shared entities (artists, albums, genres) are cleaned up only if no other library references them
• LIB-04: Libraries are stored in SQLite (not TOML config) with CRUD through the UI
• LIB-05: Existing single-directory config is migrated seamlessly to the libraries table on first run after upgrade
• LIB-06: Library list is displayed in a management UI (settings or sidebar section)

Library Scanning

• LSCAN-01: User can trigger a scan for a specific library (not all-or-nothing)
• LSCAN-02: Scanning is sequential — only one library scans at a time (SQLite single-writer)
• LSCAN-03: Scan progress UI shows which library is being scanned
• LSCAN-04: Existing scan cancellation and pause/resume work per-library
• LSCAN-05: Audio files are associated with their library via library_id foreign key

Unified Presentation

• VIEW-01: Default view shows tracks from all libraries merged (unified presentation)
• VIEW-02: User can filter the track list to show only tracks from a specific library
• VIEW-03: Browse views (albums, artists, genres) work across all libraries or filtered to one
• VIEW-04: Search (FTS5) searches across all libraries or respects the active library filter

Playlists & Queue

• PLAY-01: Playlists can contain tracks from multiple libraries (cross-library playlists)
• PLAY-02: When a library is removed, playlist entries for that library's tracks become phantom tracks (preserved with cached metadata, not cascade-deleted)
• PLAY-03: Phantom tracks are visually distinguished in playlist views (e.g., greyed out, icon indicator)
• PLAY-04: Queue tracks from a removed library are cascade-deleted (queue is ephemeral)

Data Integrity

• DATA-01: Schema migration adds libraries table and library_id FK on audio_files
• DATA-02: Orphan cleanup after library removal: reference-counting bottom-up deletes for artists, albums, genres only referenced by removed library's tracks
• DATA-03: FTS5 index entries for removed tracks are cleaned up (handling contentless table limitations)
• DATA-04: All library operations are transactional — no partial state on failure

Future Requirements

Deferred to future milestones. Tracked but not in current roadmap.

Tag Editing (Deferred from v1.1)

• TAG-01: User can edit a single track's metadata (title, artist, album, genre, year, track number)
• TAG-02: User can batch edit multiple selected tracks' shared fields
• TAG-03: Tag changes are written to actual audio files (MP3 via ID3v2, FLAC via Vorbis Comments)
• TAG-04: Database and FTS5 search index update after tag writes without requiring a full rescan
• TAG-05: User can set or replace embedded cover art from an image file
• TAG-06: Tag writes use write-to-temp-then-rename to prevent file corruption
• TAG-07: Tag editing is blocked for currently-playing files (queued for after playback stops)

Tag Editing (v2+)

• TAG-F01: Undo/redo for tag edits
• TAG-F02: Auto-capitalize and clean tag values
• TAG-F03: Filename-to-tag inference (parse "Artist - Title.mp3" patterns)
• TAG-F04: Tag-to-filename rename based on template

Smart Playlists (Deferred from v1.1)

• SMRT-01: User can create a smart playlist with filter rules (genre, year, artist, album, title)
• SMRT-02: Multiple rules combine with AND logic
• SMRT-03: User can set random ordering and result limit ("Random 50 Jazz tracks")
• SMRT-04: Smart playlists appear in the sidebar alongside regular playlists
• SMRT-05: Smart playlist rules are persisted and survive app restart

Smart Playlists (v2+)

• SMRT-F01: Play count tracking for smart playlist rules
• SMRT-F02: Rating system for smart playlist rules
• SMRT-F03: OR logic and nested boolean groups
• SMRT-F04: Sort order control in rule definition
• SMRT-F05: Auto-update smart playlists on library changes

Gapless Playback (Deferred from v1.1)

• GAP-01: Tracks transition seamlessly with no audible silence gap (gapless playback)
• GAP-02: Next track is pre-decoded before current track ends
• GAP-03: User can enable/disable crossfade with configurable duration (1-10 seconds)
• GAP-04: Crossfade only applies on auto-advance, not manual skip

Gapless Playback (v2+)

• GAP-F01: Per-album gapless (disable crossfade within albums)
• GAP-F02: ReplayGain normalization
• GAP-F03: Fade-in on play, fade-out on pause

MusicBrainz Browser (Deferred from v1.1)

• MB-01: User can search for artists by name and view results
• MB-02: User can browse an artist's discography (release groups — albums, EPs, singles)
• MB-03: User can view tracks on a specific release
• MB-04: User can view different editions of a release group (pressings, reissues)
• MB-05: API responses are cached in SQLite (24hr for searches, 7 days for entities)
• MB-06: Album cover art is displayed from the Cover Art Archive
• MB-07: Rate limiting (1 req/sec) is enforced with proper User-Agent header

Layout Customization (Deferred from v1.1)

• LAYOUT-01: User can resize sidebar and queue panels via drag handles
• LAYOUT-02: Panel sizes persist across app restarts
• LAYOUT-03: User can show/hide sidebar sections and queue panel
• LAYOUT-04: User can choose which component is displayed in each layout section (MusicBee-style)
• LAYOUT-05: Components declare size constraints (min/max dimensions, aspect ratio compatibility)
• LAYOUT-06: Layout presets available (Compact, Full, Mini player) with quick switch

Layout Customization (v2+)

• LAYOUT-F01: Detachable panels (pop out to separate window)

Plugin System (Deferred from v1.1)

• PLUG-01: Plugin API is defined — plugins can access events, player state, queue, library data
• PLUG-02: JS/TS plugin bundles are loaded from user plugin directory at runtime
• PLUG-03: Plugins can register UI components into the layout system
• PLUG-04: Plugin manifest file defines name, version, permissions, hooks, and UI components
• PLUG-05: Plugins can have their own persistent configuration
• PLUG-06: One example plugin ships demonstrating the API

Plugin System (v2+)

• PLUG-F01: Plugin marketplace/registry for discovery and installation
• PLUG-F02: Dynamic Go plugin loading for backend extensions
• PLUG-F03: Plugin permissions and sandboxing model

Out of Scope

Explicitly excluded. Documented to prevent scope creep.

Feature	Reason
Separate databases per library	Defeats unified presentation, overly complex
Auto-dedup across libraries	Complex matching logic, not table stakes
User access control per library	Desktop app, single user
Parallel library scanning	SQLite single-writer makes it pointless
OGG Vorbis tag writing	No mature pure-Go write library exists
WAV metadata editing	Rarely needed, low priority
Auto-tag from MusicBrainz	Complex matching logic — Picard's domain
DSP effects chain (equalizer, reverb)	Scope explosion — separate feature area
Go plugin package for backend plugins	Linux-only, version-fragile, widely considered broken
Free-form drag-and-drop layout	Overwhelming complexity; section-based approach is better
Global OS-level hotkeys	Platform-specific, conflicts with OS shortcuts; MPRIS2 handles media keys
Mobile-responsive layout	Desktop app with fixed minimum size

Traceability

Which phases cover which requirements. Updated during roadmap creation.

Requirement	Phase	Status
SCAN-01	Phase 9	Complete
SCAN-02	Phase 9	Complete
SCAN-03	Phase 9	Complete
KEY-01	Phase 9	Complete
KEY-02	Phase 9	Complete
KEY-03	Phase 9	Complete
KEY-04	Phase 9	Complete
KEY-05	Phase 9	Complete
LIB-01	Phase 12	Pending
LIB-02	Phase 12	Pending
LIB-03	Phase 12	Pending
LIB-04	Phase 10	Complete
LIB-05	Phase 10	Complete
LIB-06	Phase 12	Pending
LSCAN-01	Phase 11	Complete
LSCAN-02	Phase 11	Complete
LSCAN-03	Phase 11	Complete
LSCAN-04	Phase 11	Complete
LSCAN-05	Phase 10	Complete
VIEW-01	Phase 13	Pending
VIEW-02	Phase 13	Pending
VIEW-03	Phase 13	Pending
VIEW-04	Phase 13	Pending
PLAY-01	Phase 13	Pending
PLAY-02	Phase 13	Pending
PLAY-03	Phase 13	Pending
PLAY-04	Phase 12	Pending
DATA-01	Phase 10	Complete
DATA-02	Phase 12	Pending
DATA-03	Phase 12	Pending
DATA-04	Phase 10	Complete

Coverage:

• v1.1 requirements: 31 total (8 complete + 23 pending)
• Mapped to phases: 31/31 ✓ (Phase 9: 8 complete, Phases 10-13: 23 pending)
• No orphaned requirements

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Requirements defined: 2026-03-06 Last updated: 2026-03-08 — restructured for multi-library support, deferred TAG/SMRT/GAP/MB/LAYOUT/PLUG