Stt Integration

Out of scope:

• TTS-only transport changes
• telephony channel implementation
• EOS/VAD algorithm changes

Transport mapping

• WS callback baseline: deepgram, assembly-ai, sarvam
• SDK baseline: azure, google, aws
• HTTP/other baseline: provider-specific fallback keeping packet contract

Packet contract

Input:

• UserAudioPacket

Required outputs:

• SpeechToTextPacket (interim/final)
• InterruptionPacket{Source:"word"} when provider exposes speech-onset word signal
• ConversationEventPacket{Name:"stt", ...}
• MessageMetricPacket{Name:"stt_latency_ms"} per utterance

Implementation workflow

1. Select baseline provider by transport.
2. Implement STT in provider folder and callback/parser helpers.
3. Register provider in STT factory switch.
4. Wire UI model/language metadata and provider form.
5. Validate partial/final ordering and context IDs.
6. Add tests for init, interim/final, reconnect/retry, latency metric.

Validation commands

• go test ./api/assistant-api/internal/transformer/... -run TestSTT
• go test ./api/assistant-api/internal/transformer/<provider>/...
• cd ui && yarn test providers
• ./.claude/skills/stt-integration/scripts/validate.sh --check-diff --provider <provider>