led2/.planning/phases/06-ai-sync/06-03-SUMMARY.md

phase, plan, subsystem, tags, dependency_graph, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	dependency_graph	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
06-ai-sync	03	ai-sync	heuristic-generation llm-generation anthropic chroma-analysis beat-snapping ui-panel	requires provides affects phase provides 06-02 extract_features_async, detect_segments_async — audio analysis foundation phase provides 06-01 YouTube audio loading, ANTHROPIC_API_KEY wiring POST /api/sync/generate — heuristic + LLM show generation endpoint GET /api/sync/llm-available — API key presence check AI Sync panel with GENERATE button, USE LLM toggle, section range support lightsync/api/sync.py lightsync/frontend	added patterns Heuristic rule mapper: RMS-to-animation-type, chroma pitch class-to-HSL-hue color, beat-snapped block placement LLM lazy initialization: import anthropic inside function to avoid startup crash when API key missing setInterval-based segment selection watcher for reactive UI without event subscription	created modified lightsync/api/sync.py lightsync/main.py lightsync/frontend/index.html lightsync/frontend/app.js lightsync/frontend/style.css	Heuristic always runs first; LLM is opt-in via use_llm flag (D-04) LLM generates from scratch, not from heuristic output (D-06) section_range param limits generation to selected segment time window (D-11) LLM toggle disabled when ANTHROPIC_API_KEY not configured — Pitfall 4 guard claude-3-haiku-20240307 chosen for LLM model (speed vs cost)	API key guard pattern: check os.environ.get('ANTHROPIC_API_KEY') in async function, raise 503 if missing Lazy anthropic import: import inside function avoids startup crash without key	SYNC-03	8min	2026-04-07

Phase 06 Plan 03: AI-Assisted Show Generation Summary

Heuristic + LLM show generator with dedicated AI Sync panel: fills timeline with beat-snapped, energy-matched, harmonically-colored animation blocks from audio analysis.

Performance

• Duration: ~8 min
• Started: 2026-04-07T11:39:00Z
• Completed: 2026-04-07T11:47:18Z
• Tasks: 2
• Files modified: 5

Accomplishments

1. AI sync backend (lightsync/api/sync.py): POST /api/sync/generate endpoint with two generation modes:

   • heuristic_generate: section-level RMS-to-animation-type mapping, chroma pitch-class-to-HSL color, beat-grid-snapped block placement with density-adaptive grouping
   • llm_generate: Anthropic claude-3-haiku with compact feature payload, JSON parse + validation, lazy init to guard against missing API key
   • GET /api/sync/llm-available for frontend toggle gating
   • section_range parameter for per-section fill (D-11)

2. AI Sync panel UI (index.html, app.js, style.css):

   • AI SYNC button in toolbar toggles collapsible panel
   • Feature toggles: BEATS, ONSETS, CHROMA, RMS
   • GENERATE button disabled until audio loaded; re-enabled on loadedmetadata
   • USE LLM toggle: disabled when ANTHROPIC_API_KEY not set (checked via llm-available endpoint)
   • Confirmation dialog before replacing existing blocks (D-07)
   • Section-aware: if a segment band is selected, fills only that time range (D-11)
   • Info text shows FULL SHOW or SECTION: SEC N, updates via 200ms interval watcher
   • Terminal/flat aesthetic — no border-radius

Task Commits

1. Task 1: AI sync backend - b6aacad (feat)
2. Task 2: AI Sync panel UI + frontend wiring - 70b86f7 (feat)

Files Created/Modified

• lightsync/api/sync.py - New: /api/sync/generate endpoint, heuristic_generate, llm_generate, SyncGenerateRequest, _chroma_to_rgb, _intensity_to_animation
• lightsync/main.py - Register sync.router with prefix /api/sync
• lightsync/frontend/index.html - AI SYNC button, ai-sync-panel div with feature toggles and GENERATE button
• lightsync/frontend/app.js - Panel toggle, llm-available check, segment watcher, GENERATE handler with D-07/D-11 logic
• lightsync/frontend/style.css - AI sync panel styles (flat terminal aesthetic)

Decisions Made

• Heuristic always available as baseline; LLM is opt-in (D-04) — no LLM dependency for core functionality
• LLM generates independently from scratch, not post-processing heuristic output (D-06)
• claude-3-haiku-20240307 for LLM: fast and cheap for structured JSON output
• anthropic imported lazily inside llm_generate to avoid import errors at container startup without API key (Pitfall 4)

Deviations from Plan

None - plan executed exactly as written.

Known Stubs

None - all functionality is fully wired end-to-end.

Self-Check: PASSED

• lightsync/api/sync.py exists: contains router = APIRouter(), def heuristic_generate(, async def llm_generate(, async def generate_sync(, async def llm_available(, class SyncGenerateRequest, section_range: list[float] | None, use_llm: bool = False, ANTHROPIC_API_KEY, claude-3-haiku, _chroma_to_rgb, _intensity_to_animation
• lightsync/main.py contains from lightsync.api import shows, devices, ws, audio, timeline, sync and sync.router
• lightsync/frontend/index.html contains id="ai-sync-panel", id="btn-ai-sync-open", id="btn-ai-generate", id="ai-use-llm", ai-use-beats, style="display:none;"
• lightsync/frontend/app.js contains api/sync/generate, api/sync/llm-available, Replace all existing blocks, section_range, segmentOverlay?.getSelected(), GENERATING...
• lightsync/frontend/style.css contains .ai-sync-panel, .ai-sync-header, .ai-sync-generate
• Heuristic generates blocks with valid animation types and params with color/speed
• All 2 task commits exist: b6aacad, 70b86f7