MJLab (MuJoCo Lab)
April 17, 2026 ยท View on GitHub
MJLab is a GPU-accelerated robotics simulation framework built on MuJoCo (via Warp). It provides vectorized environments running entirely on GPU with fast parallel physics.
Setup
pip install -e ".[mujoco]"
pip install mjlab
How to run
Go1 Velocity (flat terrain)
python run_mjlab.py --config rl_games/configs/mjlab/ppo_go1_velocity.yaml
G1 Humanoid Velocity (flat terrain)
python run_mjlab.py --config rl_games/configs/mjlab/ppo_g1_velocity.yaml
Configs
| Environment | Config | Envs | Horizon | Epochs |
|---|---|---|---|---|
| Go1 Velocity (flat) | configs/mjlab/ppo_go1_velocity.yaml | 1024 | 16 | 3000 |
| G1 Velocity (flat) | configs/mjlab/ppo_g1_velocity.yaml | 1024 | 32 | 3000 |
Results
Go1 Flat Velocity
1024 parallel envs, ~57k FPS on RTX 5090. Converges to reward ~75 within 1000 epochs.

Go1 Rough Velocity
Central value network significantly improves rough terrain performance (~60 vs ~45 reward).

G1 Humanoid Flat Velocity
RSL-style config (v2) with separate actor-critic and entropy 0.001 reaches reward ~65. Baseline config with shared network reaches ~11.
