tts-integration

# TTS Integration Skill ## Mission Integrate TTS providers with correct streaming/flush/interruption semantics and stable `tts_latency_ms` metrics. ## Inputs expected from user 1. Transport model: bidirectional WebSocket, SSE/chunked HTTP, SDK callback, or request-response flush. 2. Voice/model parameter requirements. 3. Output audio format from provider. If user does not answer: - Select nearest baseline transport and preserve existing packet semantics. - Keep internal output format compatibility with existing streamer path. ## Hard boundaries In scope: - `api/assistant-api/internal/transformer/<provider>/tts.go` (+ provider option/normalizer helpers) - `api/assistant-api/internal/transformer/transformer.go` (factory case) - optional contract updates: `api/assistant-api/internal/type/tts_transformer.go`, `packet.go` - provider config JSON + UI component files for TTS Out of scope: - STT-only logic changes unrelated to shared provider setup - telephony transport internals - EOS/VAD internals ## Transport mapping - WS streaming baseline: `deepgram`, `rime`, `sarvam` - SSE/chunked baseline: `minimax` - SDK/API callback baseline: `azure`, `google` - HTTP flush baseline: `aws`, `resembleai` ## Packet contract Input packets: - `LLMResponseDeltaPacket` - `LLMResponseDonePacket` - `InterruptionPacket` Required outputs: - `TextToSpeechAudioPacket` - `TextToSpeechEndPacket` - `ConversationEventPacket{Name:"tts", ...}` - `MessageMetricPacket{Name:"tts_latency_ms"}` once per utterance ## Implementation workflow 1. Pick transport baseline and clone lifecycle shape. 2. Implement provider under `transformer/<provider>/`. 3. Add factory registration in `transformer.go`. 4. Wire UI metadata (`voices`, `languages`, `text-to-speech-models`) and config form. 5. Verify interruption behavior clears output state without deadlocks. 6. Add provider tests (init, streaming, completion, interruption, metric-on-first-audio). ## Governed lifecycle - Classify work as Fast, Standard, or Governed using `DEVELOPMENT_PROCESS.md`; use the full gated lifecycle only for Governed work. - This skill operates only in its assigned phase and path ownership; it may not approve its own plan or code review. - Governed implementation starts only from a coordinator-attested approved plan; Fast and Standard work follows its lighter documented lifecycle. - Return changed-file and verification evidence to the coordinator, then route the complete verified diff to the read-only `code-reviewer`. ## Validation commands - `go test ./api/assistant-api/internal/transformer/... -run TestTTS` - `go test ./api/assistant-api/internal/transformer/<provider>/...` - `cd ui && yarn test providers` - `./.claude/skills/tts-integration/scripts/validate.sh --check-diff --provider <provider>`