Vm Nebius Auth

---
name: vm-nebius-auth
description: Start, recover, or verify human Nebius CLI authentication on a remote operator/dev VM with no browser, a safe loopback callback tunnel, and secret-free identity/IAM verification. Use for remote CLI profile setup; do not replace an npa-agent VM's attached-service-account metadata profile.
---

# VM Nebius Authentication

For an operator who cannot forward the callback port but can use a private
terminal on the CLI machine, use
[nebius-headless-oauth](../nebius-headless-oauth/SKILL.md) for manual callback
delivery. Its returned URL contains a one-time code and must not pass through
chat. The tunnel flow below remains the path when SSH forwarding is available.

For unattended VM or CI work, use
[nebius-service-account-auth](../nebius-service-account-auth/SKILL.md) to
configure or verify a dedicated service identity and project-scoped grants.

## Diagnose before starting login

For a read-only readiness request, use
`npa workbench health preflight --checks nebius --json`; do not start profile
creation. A failed identity probe alone does not distinguish missing profile
configuration, expired authentication, denied access, or a network failure.
Check the selected profile's presence using the installed CLI's profile help
and non-secret metadata. Do not dump configuration or token values. Report
missing configuration only when established; otherwise leave the cause unknown.

Create or recover a human profile only when the user authorizes login. A
successful authentication check does not prove resource-creation permissions,
quota, or capacity. Preserve attached-service-account profiles on agent VMs.

Run on the operator/dev VM:

```bash
npa/.venv/bin/npa agent auth-profile \
  --ssh-host <operator-vm-host> --ssh-user <operator-vm-user> \
  --profile <profile>
```

The command strips ambient IAM-token variables, returns immediately for an
already-authenticated profile, or starts `nebius --no-browser` profile creation
and its first profile-scoped IAM probe in one PTY (CLI versions may defer OAuth
until first use). When the
CLI advertises exactly one official HTTPS browser URL and one loopback callback,
it prints the URL and an exact local-machine `ssh -N -L` command using the
runtime-selected port. Run the tunnel locally before opening the URL. Unsafe,
ambiguous, or malformed callbacks fail closed; cancellation and timeout stop the
child flow.

The browser callback completes the CLI profile. NPA then verifies `iam whoami`
and separately verifies that IAM can mint an access token, with command output
discarded. Never request, paste, print, log, return, or chat the IAM token.

Human interactive authentication is for an operator/dev VM or explicit
recovery. Keep the npa-agent VM on its attached service account and
`cursor-sa` metadata-token profile by default.

Verify changes with:

```bash
npa/.venv/bin/python -m pytest \
  npa/tests/unit/test_nebius_vm_auth.py \
  npa/tests/cli/test_agent_auth_profile.py -q
```