1 · Overview
Next: 02 Install and run
LeLab is a web app that puts the LeRobot workflow — calibrate, teleoperate, record, train, replay — into one browser window.
What you can do
| Page | What it does |
|---|---|
| Calibration | Guided calibration of both arms |
| Teleoperation | Move the leader arm; the follower mirrors it, with live joint streaming |
| Recording | Capture episodes into a LeRobotDataset, with cameras |
| Datasets | Browse episodes on disk, frame by frame, with a joint-motion trace |
| Training | Start a LeRobot training job and watch the logs |
| Inference | Run a trained policy on the follower arm |
| Upload | Push your dataset to the Hugging Face Hub |
LeLab and LeRobot
LeRobot is the library — robot drivers, dataset format, training code. LeLab is a FastAPI server that calls into it, plus a React front end that talks to that server over HTTP and WebSocket.
- Anything LeLab does not expose is still reachable through the
lerobot-*command line. - LeLab does not bundle LeRobot. Installing LeLab installs LeRobot.
Requirements
| Robot | SO-101 leader + follower arms — the only supported configuration |
| Computer | Linux, macOS or Windows |
| Python | 3.12 or newer |
| Node.js | 22 — only for lelab --dev |
| USB | Two free ports, one per arm |
Calibration, teleoperation and recording run on a laptop. Training is the heavy step, and LeLab can run it on the Hugging Face Hub instead — see page 6.
Where files go
Under ~/.cache/huggingface/lerobot/:
| Path | Contents |
|---|---|
calibration/teleoperators/so101_leader/*.json | Leader calibration files |
calibration/robots/so101_follower/*.json | Follower calibration files |
ports/leader_port.txt · ports/follower_port.txt | Last-used serial ports |
saved_configs/*.txt | Last-selected calibration profile |
Datasets go where LeRobot puts them — by default the same tree.
Clearing that cache, or reinstalling, means recalibrating both arms. See Troubleshooting.
Vocabulary
LeRobot names the arms by role; LeLab's API uses a second set of names for the same two arms:
| You say | LeRobot / LeLab say |
|---|---|
| The arm you move by hand | leader · teleop |
| The arm that follows | follower · robot |
Next: 02 Install and run