Train Policy

When To Use

Use this skill when a task asks how to train, fine-tune, evaluate, or export a robot policy through NPA workbench tools. It is the workflow-level entry point before choosing LeRobot, Isaac Lab, SONIC, or GR00T-specific skills.

Procedure

1. Identify the policy family and data contract: LeRobotDataset for LeRobot, Isaac Lab task config for RL, retargeted motion artifacts for SONIC, or model-specific inputs for GR00T.
2. Select the GPU target with skills/atomic/gpu-selection/SKILL.md.
3. Configure input and output S3 prefixes. Checkpoints and evaluation artifacts must be run-scoped.
4. Choose the executable path: direct CLI for a single tool, SDK for application code, or SkyPilot YAML for composed training workflows.
5. Verify command help and YAML parsing locally before live GPU submission.

Three-Tier Contract

• CLI: npa workbench lerobot train, npa workbench isaac-lab train, npa workbench sonic train, and related eval, export, serve, or infer commands.
• SDK: use the workbench SDK modules for application code and shared helper functions for request construction.
• YAML: isaac-lab-rl-train.yaml, sonic-train-standalone.yaml, and sim-to-real workflow YAMLs are executable references. The parallel sweep is now the npa.workflow spec workflows/testing/isaac-lab-rl-sweep.yaml (--runtime); its raw template is retired. GR00T N1.7 training uses the real workflows/testing/groot-1-7-finetune.yaml toolRef path, with gpu_count propagated into both H100 resources and the upstream trainer world size.

Gotchas

• Do not route RT-core-dependent training or render validation to H100/H200.
• Do not substitute repository-local output directories for S3 artifact paths in public examples.
• Treat tiny smoke trainers as verification substitutes only when the prompt explicitly allows minimal production-input substitution.
• Keep W&B, Hugging Face, NGC, and S3 credentials redacted.

Verify

npa/.venv/bin/python -m pytest npa/tests/guardrails/test_skills_index.py -q

The smoke test invokes training command help and parses the referenced training YAMLs.