OpenLoco

Open-source schema + compiler for hybrid robots. One descriptor emits URDF, MJCF, STL meshes, BOM, and assembly instructions.

Watch the videos View the catalog GitHub

What you get

16 robots in OpenLoco’s UDD descriptor format, spanning seven morphology families:

• Quadrupeds with feet — Stanford Pupper, Solo 12, Mini Pupper, MIT Mini Cheetah, Boston Dynamics Spot
• Wheel-leg quadrupeds — ANYmal-WL (+ autonomous variant)
• Air-ground hybrids — Caltech M4 Morphobot (+ autonomous variant)
• Wheg locomotion — Mini-Whegs (+ autonomous variant)
• Wheeled bipeds — Upkie
• Manipulation arms — SO-100, ALOHA, Reachy 2
• Aerial-only — Crazyflie

Every entry has a hand-authored descriptor plus pre-emitted artifacts in examples/baked/: URDF, MJCF, BOM, assembly. Drop them straight into ROS 2, MuJoCo, or Isaac Sim.

Use a descriptor

git clone https://github.com/openIE-dev/openloco
cd openloco/examples/baked/anymal_wl
# anymal_wl.urdf       — load in ROS 2 / RViz / Gazebo
# anymal_wl.xml        — load in MuJoCo / MJX
# bom.csv              — fabrication parts list
# assembly.md          — build instructions

How the compiler works →

Modify a descriptor

The descriptor is the source of truth. Every artifact under examples/baked/ was generated from the descriptor by the OpenLoco compiler. To modify a robot, edit its .udd.json and recompile.

The schema is small: a 12-DoF quadruped is ~150 lines of JSON.

{
  "schema_version": 1,
  "meta": { "name": "anymal_wl", "units_length": "Metre" },
  "robot": {
    "links":  [ ... ],
    "joints": [ ... ],
    "actuator_slots": [ ... ],
    "modes":  [ ... ]
  }
}

Browse all 16 →

Learn

OpenLoco builds on a deep stack of open robotics theory, control, simulation, and hardware references. The Learn page indexes the canonical free + open material — Tedrake’s Underactuated Robotics and Robotic Manipulation, LaValle’s Planning Algorithms, MuJoCo / Drake / Brax docs, mjbots Moteus and SimpleFOC references, and the open-hardware repos behind every robot in the catalog.

License

CC0-1.0 — public-domain dedication. No paywall, no enterprise tier.

Cite the upstream papers when your work depends on their ideas: Moteus (mjbots), Stanford Doggo (Kau et al.), ODRI/SOLO (Max Planck / NYU), ANYmal (RSL/ETH), Morphobot M4 (Caltech CAST, Sihite et al., Nature Communications 2023), DepthAI (Luxonis).