Ray in Workbench

Start with the consolidated guide. Use this skill to route a Ray request to behavior that current code actually supports.

Route the request

• Native Jobs or Ray Core GPU development: use docs/testing/fast-source-iteration.md and the guarded CLIP application under npa/workflows/workbench/ray-clip-development/.
• Ray Train: load skills/tools/ray-train-synthetic/SKILL.md. The shipped path is a synthetic Ray Train V2 application submitted through native Jobs, not an NPA Train service or workflow.
• Ray Serve: load skills/tools/cosmos3-ray-serve/SKILL.md. Only Cosmos3-Nano has a first-class native Ray Serve path.
• KubeRay: load skills/tools/fleet/SKILL.md. Fleet supports only the reviewed, fixed CPU RayCluster policy documented in docs/fleet-kuberay.md.
• Ray Data or Ray Tune: state that no first-class Workbench recipe, CLI, service, workflow, or artifact contract exists. A trusted user may submit their own Ray application through a supported native Jobs environment; do not imply that this makes Data or Tune a supported Workbench capability.

There is no npa ray or NPA Jobs controller. Native ray job owns application submission, list, status, logs, and stop. SkyPilot owns the CLIP and Train hosts and long-running service task. Fleet owns KubeRay infrastructure. The Cosmos client owns verified S3 batch publication. Keep these lifecycle identities separate.

Operating rules

1. Before provisioning, use npa workbench health preflight --checks nebius --json; add the selected capability's storage and model-access checks.
2. For SkyPilot references, run npa skypilot bootstrap and resolve NPA_SKYPILOT_BIN from npa skypilot status --bin-path. Never use ambient management Ray discovery or sky from PATH.
3. Keep Jobs and GCS on private networking behind an authenticated loopback tunnel. Ray accepts trusted code and a namespace is not a tenant boundary.
4. Use unique native submission IDs. ray job stop must reach terminal status before hosting teardown.
5. Preserve the path-specific artifact boundary before cleanup: checksummed CLIP output, Train checkpoints/exports, verified Cosmos S3 publications, or explicitly copied KubeRay application output.
6. Cancel exact application jobs before the exact SkyPilot service task or owned Fleet target. Preserve shared clusters, APIs, controllers, projects, and storage unless their ownership is separately established.

Do not add Ray Data/Tune examples, GPU KubeRay, RayService, a Jobs wrapper, or a new npa.workflow surface without implementation and live evidence. Do not describe multiple GPUs on one node as multi-node proof; require actual Ray node and physical-host evidence.

Verify

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