title: WebChat auto TTS delivery

scenario:
  id: webchat-auto-tts
  surface: media-understanding-and-media-generation
  category: media-understanding-and-media-generation.text-to-speech-delivery
  coverage:
    secondary:
      - media.tts
      - media.outbound-voice-audio-delivery
  objective: Verify WebChat auto-TTS synthesizes only the final reply tail and serves trusted local audio through scoped browser media tickets.
  successCriteria:
    - WebChat block delivery does not synthesize intermediate TTS audio.
    - WebChat final delivery synthesizes one local TTS audio file with spoken text metadata.
    - Trusted local TTS media becomes a WebChat audio attachment while untrusted local paths are rejected.
    - The real Gateway HTTP route mints a scoped ticket and serves the synthesized audio only with that ticket.
  docsRefs:
    - docs/tools/tts.md
    - docs/tools/media-overview.md
    - docs/concepts/qa-e2e-automation.md
  codeRefs:
    - packages/speech-core/src/tts.ts
    - src/gateway/server-methods/chat-webchat-media.ts
    - src/gateway/control-ui.ts
    - test/e2e/qa-lab/media/webchat-auto-tts.e2e.test.ts
  execution:
    kind: vitest
    path: test/e2e/qa-lab/media/webchat-auto-tts.e2e.test.ts
    summary: Vitest QA Lab coverage for mock WebChat TTS synthesis and real scoped media-ticket delivery.