vocero-client/docs/client/usage.md

Client usage and configuration

The browser voice client connects to an existing OpenAI Realtime-compatible speech backend. The UI server can also proxy WebSocket traffic, search, reasoning, caller context, ApiPilot tools and load-balancer requests.

Local startup

From the repository root:

S2S_PROXY_TARGET=ws://localhost:8765/v1/realtime ./start_ui.sh

The launcher loads the root .env, syncs vocero-api/.venv from the committed vocero-api/uv.lock, and installs the locked frontend dependencies when needed. Vite serves the React frontend on port 8420 and proxies the backend routes to Uvicorn on 127.0.0.1:8421. UI_PORT overrides the public port; S2S_BACKEND_PORT overrides the internal port. Both servers reload source edits, and stopping the launcher stops both. The speech pipeline remains a separate service. Because .env is sourced by the script, values in that file can replace variables supplied on the command line.

Use Node.js 22.18+ on the 22.x line or Node.js 24+, npm, uv 0.12.5, Bash 4.4+, setsid, and curl. Remote staging access also needs the exact hostname in S2S_DEV_ALLOWED_HOSTS, HTTPS, and WebSocket forwarding for speech and Vite HMR. See frontend development setup.

To install and start the backend manually:

uv sync --project vocero-api --locked
S2S_PROXY_TARGET=ws://localhost:8765/v1/realtime \
  uv run --project vocero-api --locked uvicorn --app-dir vocero-api vocero_api.main:app \
  --host 127.0.0.1 --port 8421 --reload --reload-dir vocero-api

Then, in a second terminal, run cd vocero-frontend, npm ci, and npm run dev.

uv provisions Python 3.12 when needed. The Python environment belongs only to vocero-api; an existing root .venv for speech dependencies is left alone. See development and compatibility for checks and schema rules.

Open http://localhost:8420/, tap the orb/microphone control, grant microphone access, and speak. Microphone access requires HTTPS or a local browser origin; use HTTPS when accessing the UI from another machine.

The speech pipeline has separate model/runtime dependencies and no complete dependency manifest in this checkout. In an already prepared speech environment, a local realtime server can be started with:

python -m speech_to_speech.s2s_pipeline \
  --mode realtime \
  --stt parakeet-tdt \
  --llm_backend transformers \
  --tts kokoro \
  --model_name Qwen/Qwen3-4B-Instruct-2507 \
  --llm_device cuda \
  --llm_torch_dtype float16 \
  --enable_live_transcription

Select backends and devices supported by the host; the example model is not a fixed deployment requirement. The default realtime endpoint is ws://localhost:8765/v1/realtime, configured through --ws_host and --ws_port. --num_pipelines controls the number of isolated concurrent realtime sessions. See LLM, STT, and TTS.

Connection modes

Configuration	Browser connection	Settings URL	Load-balancer features
SPEECH_TO_SPEECH_URL set	Direct to pinned URL	Locked	Disabled
S2S_PROXY_TARGET set, no direct URL	Same-origin /v1/realtime proxy	Locked	Disabled
LOAD_BALANCER_URL set, neither above set	Per-session compute URL from /api/session	Hidden	Allocation, queue polling and cancellation
None set	User-provided realtime URL	Editable	Disabled

Direct URLs may be full ws(s)://.../v1/realtime addresses or host values that the browser normalizes. A direct URL must be reachable from the browser. S2S_PROXY_TARGET must be reachable from the UI server. HTTPS deployments need a secure browser WebSocket URL.

The launcher supplies ws://ai-server:12345/v1/realtime as a proxy-target default when no value is configured. That hostname must resolve from the UI server; it is not a universally available local service.

Docker

This image serves FastAPI backend routes and shared documentation. Run the React frontend separately with Vite and point S2S_BACKEND_URL at the exposed backend address. The image does not run the development launcher or serve a UI.

Use the project root as the build context:

docker build -f vocero-api/Dockerfile -t vocero-api .
docker run --rm -p 7860:7860 \
  -e SPEECH_TO_SPEECH_URL=ws://localhost:8765/v1/realtime vocero-api

For the proxy path, replace the direct setting with a server-reachable S2S_PROXY_TARGET. If the upstream is another container, attach the UI to the appropriate existing network and use that service's hostname. An upstream bound only to host loopback is not reachable via an arbitrary container name.

The image includes vocero-api and root docs. /docs is still the FastAPI API explorer; documentation lives under /docs/client/, /docs/speech/, /docs/adr/, /docs/examples/, and /docs/proposals/. Legacy /project/ and /public/docs.html redirect to the historical proposal. Markdown is served as a source file rather than rendered through a separate documentation site. Request file paths such as /docs/README.md; directories without index.html are not browsable pages.

Settings and tools

Voice, editable system instructions and connection settings are kept in browser localStorage under s2s.ws.* keys. A non-empty S2S_PRIMARY_PROMPT pins the instruction field. Restart applies connection/voice changes to a new session. Settings and tool preferences use a draft: Guardar applies them and Cancelar or dialog dismissal discards unsaved edits. Voice and instructions update the live session on Save; connection changes apply on the next start. Noise-gate calibration is explicitly live and saves immediately. Model voice names are runtime identifiers and stay unchanged across UI translations.

Web search needs SERPER_API_KEY on the server or a user-supplied key in the tools panel. The server proxies requests through /api/search; its own key is not returned to the browser. Dynamic ApiPilot tools are configured through S2S_APIPILOT_TOOLS_URL; see tool calling.

Operator RAG text is applied through the RAG dialog and updates live instructions. Caller links may include phoneNumber=%2B...; episode links may include episode_id=.... See context injection for enabled data sources and limits.

Theme and session startup

S2S_THEME=white selects the light interface. dark or an empty value selects the dark aurora theme. Theme-specific sections remain hidden until configuration resolves, with a fallback to avoid an invisible page after config failure. Configuration failures offer Reintentar and block session startup until a retry succeeds. Reports load independently. Caller context gets an eight-second loading window before the interface allows a generic session.

S2S_START_SESSION_MODE controls initial microphone/session startup:

Value	Behavior
Empty/default	User taps to start
TALK	Attempt automatic start and inject the Spanish wake phrase as soon as configuration and caller context are ready
TALKFIRST	Same automatic startup behavior as TALK

Automatic startup runs once per page load, without a startup dialog or artificial delay; optional reports and tools can still be loading. Browser permission and audio policies can still require a gesture. When audio is blocked, an inline hint asks the user to tap the microphone button. Permission or connection failures show the error and leave the same button available to retry. Stopping a session does not start it again automatically. The greeting uses the same hola vocero input as wake-word handling.

On browsers with speech recognition, Activar con «hola vocero» opts into wake-word listening for the current page session. The interface shows when the microphone is listening for that phrase. It is off by default, pauses while a dialog or voice session is active, and turns off when the conversation stops.

The transcript keeps your reading position when new messages arrive. Ir al último mensaje resumes following the conversation. Names and Santiago-local times appear with each message; downloaded JSON and text retain raw timestamps and message text. The interface respects the browser's reduced-motion setting.

Queue and session lifecycle

Load-balancer mode proxies POST /api/session. A free compute slot returns a grant containing session_id, connect_url, and pending_timeout_s. Otherwise the browser receives a queue ticket and polls GET /api/queue/{queue_id} until a slot is granted. The browser offers a timed join action after waiting.

DELETE /api/queue/{queue_id} cancels a waiting ticket. On session stop or page exit, the browser uses POST /api/queue/end through sendBeacon, falling back to a keepalive fetch. Expired tickets and missed join deadlines require a new attempt. Full queues return 503 with state: "at_capacity".

Once connected, session teardown closes the microphone, audio graph and WebSocket. The 30-second inactivity timeout counts time waiting for user input; processing, external reasoning and buffered playback do not consume it. Caller-profile lookup and upstream authorization operate independently of allocation and use their existing configured endpoints.

For external transcript processing, configure the selected reasoning mode. For connection, context and audio diagnostics, use troubleshooting.