vllm-omni/examples/online_serving/personaplex

PersonaPlex full-duplex online serving

Serve nvidia/personaplex-7b-v1 (a Moshi-based full-duplex speech-to-speech model) with the native vLLM-Omni engine through the unified duplex serving stack (/v1/duplex and /v1/realtime?duplex=1).

Requires a GPU and Hugging Face access to the gated repo (HF_TOKEN with access to nvidia/personaplex-7b-v1).

Start the server

The default vllm_omni/deploy/personaplex.yaml enables the engine-owned full-duplex control plane (session_mode: duplex):

HF_TOKEN=... CUDA_VISIBLE_DEVICES=0 python -m vllm_omni.entrypoints.cli.main serve \
  /path/to/personaplex-7b-v1 \
  --omni \
  --deploy-config vllm_omni/deploy/personaplex.yaml

This exposes:

• WS /v1/duplex — the native duplex session dialect (session.create / input_audio_buffer.append / response.output_audio.delta ...);
• WS /v1/realtime?duplex=1 — the same sessions projected onto the OpenAI Realtime event vocabulary (client API and wire protocol: docs/serving/realtime_duplex_api.md).

PersonaPlex is a pure-lockstep model: every session on a PersonaPlex deployment is native duplex (is_enabled() is unconditionally true), audio flows continuously in both directions, and there are no client commits or external turn signals (supports_client_commit=false, supports_external_turn_signal=false).

Validate the serving path

Validate the /v1/realtime?duplex=1 scheduler path with paced 24 kHz PCM, two concurrent sessions, overflow admission, per-session slot recycling, and non-silent output:

python tests/e2e/online_serving/personaplex_realtime_duplex.py \
  --model /path/to/personaplex-7b-v1 \
  --input-wav /path/to/speech.wav \
  --output-dir /tmp/personaplex-realtime-duplex

The unified endpoint advertises supports_barge_in=false: overlapping speech is native model behavior, but destructive output interruption and model-state rewind have not been validated for PersonaPlex.

Notes

• Run the client near the server. Real-time 80 ms frame audio is sensitive to network latency/jitter; over a high-latency remote link playback can stutter regardless of engine speed. On localhost it is smooth.
• The earlier standalone Moshi-web compatibility server (browser client at /, binary WS protocol at /api/chat, raw-PCM /v1/audio/duplex) was demo-only and has been removed; use the unified endpoints above.
• Session config (voice / persona / sampling) is passed per session via extra_body; see vllm_omni/model_executor/models/personaplex/duplex/serving_adapter.py.
• Full runbook: recipes/NVIDIA/PersonaPlex.md.