Pepijn 223cc8a9e2 feat(smolvla2): inference runtime — select_message + multi-rate REPL
Closes the loop on PR 3: SmolVLA2 can now be queried interactively at
inference, dispatching the same five sub-recipe shapes it was trained
on (action chunks, subtask gen, memory updates, plan/speech on
interjection, VQA on questions).

Modeling fixes + additions
--------------------------

- ``_compute_text_loss``: standard next-token CE shift was missing
  (logits at position t were CE'd against the label at t — identity-
  mapped, learning nothing). Adds ``logits[:, :-1]`` /
  ``labels[:, 1:]`` shift to match HuggingFace ``LlamaForCausalLM``.

- New ``select_message`` on ``SmolVLA2Policy``: AR text generation
  with KV caching, mirroring SmolVLA's ``select_action`` pattern.
  Single prefix forward fills the cache, then per-token forwards
  reuse it. Greedy + top-p nucleus sampling. Returns the decoded
  string with the prompt stripped.

Runtime package — ``src/lerobot/policies/smolvla2/inference/``
-------------------------------------------------------------

- ``triggers.py`` — ``Trigger`` Protocol + ``HzTrigger`` /
  ``EventTrigger`` + ``TickClock``. The whole runtime ticks at
  ``max_rate_hz=50`` and each step gates itself off its own
  cadence.

- ``runtime_state.py`` — runtime state dict factory plus tiny
  helpers (``take_event``, ``set_if_changed``, ``push_log``).
  Stable keys are documented at the top of the module.

- ``steps.py`` — :class:`InferenceStep` base + concrete steps:
  ``LowLevelForward`` / ``DispatchAction`` (action path),
  ``HighLevelSubtaskFwd`` / ``MemoryUpdateFwd`` /
  ``UserInterjectionFwd`` / ``AskVQAFwd`` (text paths),
  ``DispatchToolCalls`` (tool registry → ``Tool.call``). Each
  text step builds a chat-template prompt from current
  ``RuntimeState`` (task / plan / memory / subtask) matching
  what ``smolvla2_hirobot.yaml`` renders during training.
  Includes a tiny ``<say>...</say>`` parser for the
  ``user_interjection_response`` branch's combined plan + speech
  output.

- ``runtime.py`` — :class:`SmolVLA2Runtime` composes the pipeline,
  drives ticks via ``TickClock``, polls a user-supplied
  ``event_collector`` per tick, and prints state-change log lines.

- ``repl.py`` — :class:`StdinReader` non-blocking line reader
  with simple intent classification: ``stop`` / ``quit`` /
  ``exit`` → terminate; ``?`` suffix → ``user_vqa_query`` event;
  first line → set task; other lines → ``user_interjection``.

CLI
---

- ``src/lerobot/scripts/lerobot_smolvla2_runtime.py``: console
  script ``lerobot-smolvla2-runtime`` that loads a checkpoint,
  optionally instantiates ``SayTool`` (pocket-tts), wires up
  ``SmolVLA2Runtime`` + ``StdinReader``, and runs.

  Real-robot wiring (observation_provider / robot_executor) is
  intentionally left as a follow-up — v1 is dry-run / language-
  only so the REPL works without robot hardware.

  Registered in ``pyproject.toml`` ``[project.scripts]``.

Known follow-ups
----------------

- Real-robot integration: today ``LowLevelForward`` only fires when
  an observation_provider is wired. The CLI prints a warning if
  ``--no_robot`` is omitted.
- ``select_message`` runs an extra prefix forward; could share with
  the action path's prefix when both are needed in the same tick.
- Tests: no end-to-end runtime test yet (would need a tiny SmolVLM
  fixture). The components compile and the public surface is
  exercised by the CLI's argument-parsing path.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-30 22:04:00 +02:00
2025-03-13 14:05:55 +01:00
2025-06-05 17:48:43 +02:00
2026-04-06 12:23:37 +02:00
2026-02-28 14:41:28 +01:00
2024-03-25 12:28:07 +01:00
2026-01-16 14:38:42 +01:00

LeRobot, Hugging Face Robotics Library

Tests Tests Python versions License Status Version Contributor Covenant Discord

LeRobot aims to provide models, datasets, and tools for real-world robotics in PyTorch. The goal is to lower the barrier to entry so that everyone can contribute to and benefit from shared datasets and pretrained models.

🤗 A hardware-agnostic, Python-native interface that standardizes control across diverse platforms, from low-cost arms (SO-100) to humanoids.

🤗 A standardized, scalable LeRobotDataset format (Parquet + MP4 or images) hosted on the Hugging Face Hub, enabling efficient storage, streaming and visualization of massive robotic datasets.

🤗 State-of-the-art policies that have been shown to transfer to the real-world ready for training and deployment.

🤗 Comprehensive support for the open-source ecosystem to democratize physical AI.

Quick Start

LeRobot can be installed directly from PyPI.

pip install lerobot
lerobot-info

Important

For detailed installation guide, please see the Installation Documentation.

Robots & Control

Reachy 2 Demo

LeRobot provides a unified Robot class interface that decouples control logic from hardware specifics. It supports a wide range of robots and teleoperation devices.

from lerobot.robots.myrobot import MyRobot

# Connect to a robot
robot = MyRobot(config=...)
robot.connect()

# Read observation and send action
obs = robot.get_observation()
action = model.select_action(obs)
robot.send_action(action)

Supported Hardware: SO100, LeKiwi, Koch, HopeJR, OMX, EarthRover, Reachy2, Gamepads, Keyboards, Phones, OpenARM, Unitree G1.

While these devices are natively integrated into the LeRobot codebase, the library is designed to be extensible. You can easily implement the Robot interface to utilize LeRobot's data collection, training, and visualization tools for your own custom robot.

For detailed hardware setup guides, see the Hardware Documentation.

LeRobot Dataset

To solve the data fragmentation problem in robotics, we utilize the LeRobotDataset format.

  • Structure: Synchronized MP4 videos (or images) for vision and Parquet files for state/action data.
  • HF Hub Integration: Explore thousands of robotics datasets on the Hugging Face Hub.
  • Tools: Seamlessly delete episodes, split by indices/fractions, add/remove features, and merge multiple datasets.
from lerobot.datasets.lerobot_dataset import LeRobotDataset

# Load a dataset from the Hub
dataset = LeRobotDataset("lerobot/aloha_mobile_cabinet")

# Access data (automatically handles video decoding)
episode_index=0
print(f"{dataset[episode_index]['action'].shape=}\n")

Learn more about it in the LeRobotDataset Documentation

SoTA Models

LeRobot implements state-of-the-art policies in pure PyTorch, covering Imitation Learning, Reinforcement Learning, and Vision-Language-Action (VLA) models, with more coming soon. It also provides you with the tools to instrument and inspect your training process.

Gr00t Architecture

Training a policy is as simple as running a script configuration:

lerobot-train \
  --policy=act \
  --dataset.repo_id=lerobot/aloha_mobile_cabinet
Category Models
Imitation Learning ACT, Diffusion, VQ-BeT, Multitask DiT Policy
Reinforcement Learning HIL-SERL, TDMPC & QC-FQL (coming soon)
VLAs Models Pi0Fast, Pi0.5, GR00T N1.5, SmolVLA, XVLA

Similarly to the hardware, you can easily implement your own policy & leverage LeRobot's data collection, training, and visualization tools, and share your model to the HF Hub

For detailed policy setup guides, see the Policy Documentation.

Inference & Evaluation

Evaluate your policies in simulation or on real hardware using the unified evaluation script. LeRobot supports standard benchmarks like LIBERO, MetaWorld and more to come.

# Evaluate a policy on the LIBERO benchmark
lerobot-eval \
  --policy.path=lerobot/pi0_libero_finetuned \
  --env.type=libero \
  --env.task=libero_object \
  --eval.n_episodes=10

Learn how to implement your own simulation environment or benchmark and distribute it from the HF Hub by following the EnvHub Documentation

Resources

Citation

If you use LeRobot in your project, please cite the GitHub repository to acknowledge the ongoing development and contributors:

@misc{cadene2024lerobot,
    author = {Cadene, Remi and Alibert, Simon and Soare, Alexander and Gallouedec, Quentin and Zouitine, Adil and Palma, Steven and Kooijmans, Pepijn and Aractingi, Michel and Shukor, Mustafa and Aubakirova, Dana and Russi, Martino and Capuano, Francesco and Pascal, Caroline and Choghari, Jade and Moss, Jess and Wolf, Thomas},
    title = {LeRobot: State-of-the-art Machine Learning for Real-World Robotics in Pytorch},
    howpublished = "\url{https://github.com/huggingface/lerobot}",
    year = {2024}
}

If you are referencing our research or the academic paper, please also cite our ICLR publication:

ICLR 2026 Paper
@inproceedings{cadenelerobot,
  title={LeRobot: An Open-Source Library for End-to-End Robot Learning},
  author={Cadene, Remi and Alibert, Simon and Capuano, Francesco and Aractingi, Michel and Zouitine, Adil and Kooijmans, Pepijn and Choghari, Jade and Russi, Martino and Pascal, Caroline and Palma, Steven and Shukor, Mustafa and Moss, Jess and Soare, Alexander and Aubakirova, Dana and Lhoest, Quentin and Gallou\'edec, Quentin and Wolf, Thomas},
  booktitle={The Fourteenth International Conference on Learning Representations},
  year={2026},
  url={https://arxiv.org/abs/2602.22818}
}

Contribute

We welcome contributions from everyone in the community! To get started, please read our CONTRIBUTING.md guide. Whether you're adding a new feature, improving documentation, or fixing a bug, your help and feedback are invaluable. We're incredibly excited about the future of open-source robotics and can't wait to work with you on what's next—thank you for your support!

SO101 Video

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