Beyond motion planning. Build robot cells as code.

pip install botrail, a few lines of Python, and you get an interactive 3D studio in your browser for building robot cells — robots, obstacles, conveyors, sensors, and PLC-style sequences. The core is written in Rust: no ROS, no system dependencies, no GPU.

Get started Try the live studio

Four stations, eight arms, three bodies in flight — one program per station plus a transfer program, baked into one deterministic takt (examples/welding/weld_line_demo.py --stations 4).

What makes it different

A cell in botrail is text — Python, a .botrail project, or USD. It diffs in git, it bakes into a bit-identical timeline every run, and it regression-tests in CI. Motions are planned, not taught point by point, so moving a pallet or a sensor doesn't break the cell: re-simulate and read the new cycle time.

import botrail as bt

robot = bt.Robot.from_urdf("arm.urdf")     # or from_xacro(...) / from_usd(...)
scene = bt.Scene(robot)
scene.add_box("table", size=(0.6, 0.6, 0.05), position=(0.4, 0.0, 0.0))

bt.studio(scene)                           # opens the 3D studio in your browser

Give the environment behavior, write the process as steps, and bake it:

tl = scene.simulate_sequence("cycle")   # deterministic: bit-identical every run
print(tl.duration)                      # cycle time in seconds
tl.export_usd("cycle.usda", fps=60)     # replay in usdview / Omniverse / Blender

Because the bake is deterministic, the same numbers are your tests:

def test_cell_cycle():
    tl = build_cell().simulate_sequence("cycle")
    assert tl.duration <= 8.0                # cycle-time budget
    assert tl.step_span("feed").end <= 2.0   # the crate arrives on time
    assert tl.signal("eye").rising_edges()   # the handshake happened
    assert tl.min_clearance() > 0.05         # closest approach, meters

Move the beam sensor downstream and the cycle grows by a predictable amount — a layout edit becomes a failing test instead of a shop-floor surprise.

Feature tour

• Robots from URDF, Xacro, or USD

  Including Isaac Sim articulations. Mimic joints are followed, so a two-finger gripper costs one DOF, not two. Multiple robots per cell, with tick-checked inter-robot collisions and zone interlocks.

• USD scene import

  usda/usdc/usdz with references, variants, and instancing. Stages become obstacles and named mount frames, normalized to meters and Z-up.

• Environments that behave

  A PLC-style step sequencer, zone/beam sensors, conveyors and linear axes, and conveyor tracking: taught poses ride the moving part, so the belt never stops for the pick.

• Assertable timelines

  step_span(), signal(), and min_clearance() turn a bake into pytest-able cell checks that run in CI.

• Open deliverables

  USD animation, CSV/JSON, robot programs (URScript), Python code generation — and the engineering documents: I/O list, bill of materials, layout sheet (SVG/DXF), cell report, all derived from the same script. Isaac Sim recordings play back through the same pipeline.

• Runs in the browser

  The wasm build serves the full studio as a static page, no server. Drop a USD file straight into the viewport.

Where to go next

If you want to…	Read
Install the package and check it works	Installation
Load a robot, plan a motion, open the studio	Quickstart
Build a cell that runs a cycle and test it	Your first cell
Watch real cells get built, step by step	Tutorials
Go deep on one topic — tracking, sensors, export…	Guides
Learn the studio UI	The studio
Understand the positioning and the trade-offs	Why botrail
Look up a method	API reference
Build from source or contribute	Contributing