docs(37): auto-generated context (discuss skipped)

.planning/phases/37-web-chat-voice-ui/37-CONTEXT.md

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+# Phase 37: Web Chat Voice UI - Context
+
+**Gathered:** 2026-04-04
+**Status:** Ready for planning
+**Mode:** Auto-generated (discuss skipped via workflow.skip_discuss)
+
+<domain>
+## Phase Boundary
+
+Users can speak to any agent in web chat — recording auto-stops on silence, a live waveform confirms the mic is active, responses play back automatically (toggleable), and voice mode is a first-class setting.
+
+Requirements: WCHAT-01, WCHAT-02, WCHAT-03, WCHAT-04, WCHAT-05, WCHAT-06
+
+</domain>
+
+<decisions>
+## Implementation Decisions
+
+### Claude's Discretion
+All implementation choices are at Claude's discretion — discuss phase was skipped per user setting. Use ROADMAP phase goal, success criteria, and codebase conventions to guide decisions.
+
+Key research findings to incorporate:
+- `@ricky0123/vad-react ^0.0.36` for browser-side silence detection (VAD) — delivers Float32Array at 16kHz on speech end
+- COOP/COEP headers required on Express server for SharedArrayBuffer (`Cross-Origin-Opener-Policy: same-origin`, `Cross-Origin-Embedder-Policy: require-corp`)
+- Waveform via Web Audio API AnalyserNode (Canvas or SVG, 30-50 data points)
+- Native `<audio>` element + URL.createObjectURL() for playback — no extra library needed
+- Three-state voice mode: "text" | "voice_input" | "full_voice" (already in nexus-settings schema from Phase 36)
+- VoiceMicButton replaces/enhances existing VoiceRecordButton from v1.5
+- Voice badge + expandable markdown section in ChatMessage for voice interactions
+- AudioContext must be unlocked on user's "start voice mode" gesture to avoid autoplay policy blocks
+- Existing hooks: usePiperTts (client-side TTS), VoiceRecordButton (MediaRecorder), TtsButton
+- POST /api/transcribe and POST /api/synthesize endpoints available from Phase 36
+
+</decisions>
+
+<code_context>
+## Existing Code Insights
+
+### Reusable Assets
+- `ui/src/components/VoiceRecordButton.tsx` — existing MediaRecorder-based recording button
+- `ui/src/components/TtsButton.tsx` — existing TTS playback button
+- `ui/src/hooks/usePiperTts.ts` — client-side Piper WASM TTS hook
+- `server/src/routes/voice.ts` — POST /api/transcribe, POST /api/synthesize (Phase 36)
+- `server/src/services/nexus-settings.ts` — voiceMode setting already in schema
+
+### Established Patterns
+- React hooks in ui/src/hooks/
+- Components in ui/src/components/
+- Settings via nexus-settings service + React hooks
+
+### Integration Points
+- `ui/src/components/ChatInput.tsx` — mic button integration point
+- `ui/src/components/ChatMessage.tsx` — voice badge + audio player
+- Express static middleware — COOP/COEP headers
+- `server/src/app.ts` — header middleware
+
+</code_context>
+
+<specifics>
+## Specific Ideas
+
+No specific requirements — discuss phase skipped. Refer to ROADMAP phase description and success criteria.
+
+</specifics>
+
+<deferred>
+## Deferred Ideas
+
+None — discuss phase skipped.
+
+</deferred>