Release Notes for NeMo Voice Agent

View as Markdown

Dated feature updates for NeMo Labs Voice Agent appear newest first. This page is the documentation site’s canonical history of automatic speech recognition (ASR), large language model (LLM), text-to-speech (TTS), and evaluation milestones.

There are no per-entry version tags: the package version is a single value declared in nemo_voice_agent/package_info.py and exposed as nemo_voice_agent.package_info.__version__. For changes after the most recent entry, refer to the repository commit history.

Release History

The following table summarizes the dated project milestones documented on this page.

DateHighlights
2026-08-06Graduated to a standalone repository
2026-06-13Voice-agent evaluation harness with four benchmark domains
2026-05-15Omni (multimodal) LLM support
2026-01-26Nemotron-3-Nano-30B-A3B-BF16 LLM and Magpie multilingual TTS
2025-12-31Tool-calling examples and diarization model upgrade
2025-11-14Joint ASR and end-of-utterance detection
2025-10-10Kokoro-82M TTS
2025-10-03vLLM serving with automatic Hugging Face fallback
2025-09-05First release

2026-08-06 — Standalone Repository

NeMo Labs Voice Agent graduated out of NVIDIA-NeMo/Speech, where it had lived as a sub-package. Development now occurs in its own repository. The Python package name (nemo_voice_agent) and every import path are unchanged.

2026-06-13 — Evaluation Harness

This milestone shipped the two-bot evaluation harness. A simulated user bot talks to the agent under test through a bridge that transfers audio between two WebSocket Pipecat servers and scores the outcome.

The release ported four benchmark domains:

DomainScenariosUpstream Source
eva_airline50ServiceNow eva
tau2_airline50tau2-bench airline
tau2_retail114tau2-bench retail
tau2_telecom114tau2-bench telecom (dual-side: separate agent-side and user-side databases)

tau2_telecom is registered twice — a second tau2_telecom_workflow family shares the same 114 upstream tasks and differs only in which policy file is rendered into the agent prompt.

Scoring is per-scenario: each scenario declares a success_signals whitelist over the six signals is_action_match, db_state_match, db_state_assertion, nl_assertion, judge_passed, and clean_exit.

Learn more: Evaluation overview · Benchmarks · Scoring · eva_airline · tau2_airline · tau2_retail · tau2_telecom

2026-05-15 — Omni and Multimodal LLM Support

Added support for nvidia/Nemotron-3-Nano-Omni-30B-A3B-Reasoning-NVFP4, served through the llm_configs/nemotron_nano_v3_omni.yaml model config (a _think.yaml sibling enables reasoning). Omni models consume user audio directly, so the pipeline inserts a user audio buffer stage that non-omni pipelines omit.

Learn more: Multimodal models · Reasoning

2026-01-26 — Nemotron-3-Nano-30B-A3B and Magpie TTS

This milestone added the following language and speech model support.

  • Added support for the nvidia/NVIDIA-Nemotron-3-Nano-30B-A3B-BF16 LLM. The llm_configs/nemotron_nano_v3.yaml model configuration covers this family. The NVFP4 variant is the shipped default and needs a GPU with FP4 support.
  • Added support for the nvidia/magpie_tts_multilingual_357m TTS model. Its configuration is tts_configs/magpie_tts_multilingual_357m.yaml.

Learn more: LLM backends · TTS · Model registry

2025-12-31 — Tool-Calling Examples and Diarization Upgrade

This milestone expanded tool-calling examples and updated the default diarization model.

  • Added tool-calling examples. The Kokoro TTS service lets the LLM change how the agent sounds mid-conversation. It registers tool_tts_speak_faster, tool_tts_speak_slower, tool_tts_set_speed, tool_tts_reset_speed, tool_tts_set_voice (American or British accent, male or female voice), and tool_tts_reset_voice. A standalone example function, tool_get_city_weather, looks up current weather with the python_weather package.
  • Updated the diarization model to nvidia/diar_streaming_sortformer_4spk-v2.1, which handles up to four speakers across user turns.

Learn more: Tool calling · Custom tools · Diarization

2025-11-14 — Joint ASR and End-of-Utterance Detection

Added support for nvidia/parakeet_realtime_eou_120m-v1, which predicts end-of-utterance jointly with transcription. It is the shipped default STT model and is optimized for lowest latency. It does not emit punctuation or capitalization.

Learn more: ASR · Turn taking

2025-10-10 — Kokoro-82M TTS

Added support for the hexgrad/Kokoro-82M TTS model, configured through tts_configs/kokoro_82M.yaml.

Learn more: TTS

2025-10-03 — vLLM Serving and Automatic Backend Selection

This milestone added the following serving and backend-selection capabilities.

  • Added vLLM as an LLM serving backend alongside Hugging Face.
  • Added automatic backend selection: with llm.type: auto, the server tries vLLM first and falls back to Hugging Face, so parameters for both backends must be valid.
  • Made nvidia/NVIDIA-Nemotron-Nano-9B-v2 the default LLM at the time. The current default is the Nemotron-3-Nano-30B-A3B family, as described in the 2026-01-26 entry.

Learn more: vLLM backend · LLM backends

2025-09-05 — First Release

First release of NeMo Labs Voice Agent: a real-time speech-to-speech pipeline built on Pipecat, with streaming ASR, speaker diarization, LLM, and TTS behind a WebSocket server, plus a browser client. Shipped at the time as a sub-package of NVIDIA-NeMo/Speech. Refer to the 2026-08-06 entry for the move to a standalone repository.

Learn more: Architecture · Quickstart

Upcoming Work

The repository README.md lists the following planned work:

  • Accuracy and robustness improvements to the ASR models.
  • Combined ASR and speaker diarization to handle overlapping speech.
  • More evaluation domains and scenarios.

Use these pages to begin with the current project, understand its architecture, or review its evaluation capabilities.