# identity

The step-level `identity` field authenticates an Atmos auth identity before the step runs, so the step executes with the right cloud credentials.

```yaml
steps:
  - name: deploy-vpc
    command: terraform apply vpc -s plat-ue2-prod
    identity: superadmin
```

When an identity is specified, Atmos authenticates it, prepares temporary credentials, and passes the resulting environment to the subprocess.

The command-line `--identity` flag provides a default identity for steps that do not set their own. A step-level `identity` overrides the command-line value.

Configure identities in [`auth`](/cli/configuration/auth).