Files
Mujoco_WASM/mjx
Sam Haves dade2d8c3e MJX: Use content-hash for np.ndarray pytree metadata fields
Previously mjx dataclasses would return np.ndarray as bytes for jax tracing to hash since they are not inherently hashable. This meant that any tracing that was cached would hold on to a copy of the numpy arrays in the dataclass. Children such as mjx.Model that store large numpy arrays would end up duplicating that data 3+ times in some cases.

This eliminates O(N * array_size) memory duplication across N cached
pytree traces, saving a lot of memory on models with heavy mesh/texture data.

PiperOrigin-RevId: 880985898
Change-Id: I58d4e91fda4112e4c633818f92907d20138e962a
2026-03-09 12:35:16 -07:00
..
2025-01-23 02:51:51 -08:00

MuJoCo XLA (MJX)

PyPI Python Version PyPI version

This package is a re-implementation of the MuJoCo physics engine in JAX. This library is developed and maintained by Google DeepMind, and is kept up-to-date with the latest developments in MuJoCo itself.

The mujoco-mjx package is API-compatible with MuJoCo, but is missing some features found in MuJoCo. See our documentation for more details concerning feature parity.

Installation

The recommended way to install this package is via PyPI:

pip install mujoco-mjx

Usage

Once installed, the package can be imported via from mujoco import mjx. Please consult our documentation for further detail on the package's API.

We recommend going through the tutorial notebook which introduces the MJX API and trains a reinforcement learning policy in a few minutes: Open In
Colab

Versioning

The major.minor.micro portion of the version number matches the version of MuJoCo that this library provides. Optionally, if we release updates to MJX that target the same version of MuJoCo, a .postN suffix is added, for example 3.0.1.post2 represents the second update to MJX for MuJoCo 3.0.1.

License and Disclaimer

Copyright 2023 DeepMind Technologies Limited

MuJoCo and its libraries are licensed under the Apache License, Version 2.0. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0.

This is not an officially supported Google product.