Add a robot

Add a robot#

Every robot is a registered entity: its model, actuators, body names and tasks plug into the shared MDP without touching it. There are two ways to register one.

From model files — no code

Upload the MJCF / URDF in the Studio. Wiring and PD gains are suggested, checked on a floor and saved per user; tasks Wbc-<Id>, -SE and -Terrain-Scan appear at once.

Best for trying a robot, research across embodiments.

Add a robot from model files
As an extension package

A Python package calling register_wbc_extension: full control over actuator models, symmetry for mirroring, any task table; ships with your platform.

Best for a robot you maintain and deploy.

Extension packages

Both paths give a robot that every command and the Studio treat like the built-in G1. Starting with the Studio and moving to a package later is common — the saved robot.yaml holds the numbers the package’s constants need.

Walkthrough: extension → data → train#

The extension path end to end, for a robot my_robot with clips my_data.

  1. Create the package following wbc-mjlab-extension-h2 (Example: H2 extension walks through it) and install it next to wbc-mjlab:

    uv pip install -e ../my-robot-wbc
uv run wbc-mjlab-list-envs          # lists Wbc-MyRobot

  2. Retarget clips to the robot (e.g. with GMR) and put them in the extension’s data tree: <project_root>/data/my_robot/my_data/*.csv.

  3. Check and train (the clips are read as they are — check them in the Studio’s Data):

    uv run wbc-mjlab-train --task Wbc-MyRobot --dataset my_data

Checklist#

Before publishing an extension or opening a PR:

  1. No MDP forks — rewards, sampling and terminations stay in env/mdp/; use presets

  2. Registered — register_wbc_extension runs at import, from a mjlab.tasks entry point

  3. Names explicit — anchor, keybodies and end-effectors as constants

  4. Motion wired — a RobotMotionSpec (feet for --debias-z, the scene for wbc-mjlab-data-to-npz --robot <id>)

  5. Tasks — WbcTaskConfig entries with the matching robot_id

See also