# atmos scaffold validate

Validate a template's `scaffold.yaml` before it reaches a developer or CI. Validation checks the
versioned manifest contract; generation then validates the answers supplied to that contract.

## Usage

```shell
atmos scaffold validate [path]
```

```shell
atmos scaffold validate
atmos scaffold validate ./scaffolds/terraform-component
```

## Valid Manifest

```yaml title="scaffold.yaml"
apiVersion: atmos/v1
kind: AtmosScaffoldConfig
metadata:
  name: terraform-component
  description: Standard Terraform component
  version: 1.0.0
spec:
  fields:
    - name: component_name
      label: Component name
      type: input
      required: true
      validation:
        pattern: "^[a-z0-9-]+$"
        message: Use lowercase letters, digits, and hyphens.
    - name: region
      type: select
      options: [us-east-1, us-west-2]
      default: us-east-1
    - name: environments
      type: multiselect
      options: [dev, staging, prod]
      default: [dev]
    - name: enable_monitoring
      type: confirm
      default: false
    - name: alert_email
      type: input
      when: "answers.enable_monitoring == true"
  files:
    - path: monitoring.tf
      when: "answers.enable_monitoring == true"
```

The required manifest identity is `apiVersion: atmos/v1`, `kind: AtmosScaffoldConfig`, and
`metadata.name`. `metadata.description`, `metadata.author`, and `metadata.version` are optional
metadata. `spec.values`, `spec.source`, and `spec.baseRef` are normally persisted by generation to
record answers and provenance for updates.

## What Validation Checks

- Manifest identity, YAML shape, field names, supported field types, and field-specific options.
- The `when:` representation: a predicate/CEL string or list is valid; map-style
  `{all, any, not}` conditions are rejected for scaffold manifests.
- Regex syntax in `validation.pattern` and structural constraints in the generated JSON Schema.
- Conditional file entries and the step-backed hook configuration shape.

`atmos scaffold validate` checks template configuration. `atmos scaffold generate` additionally
checks concrete answers: required text, select/multiselect options, boolean coercion, and regex
matches across prompts, defaults, persisted values, and `--set` flags.

## Common Fixes

Use `spec.fields`, not the retired `prompts:` key:

```yaml
# Invalid
prompts:
  - name: component_name
    type: input

# Valid
spec:
  fields:
    - name: component_name
      type: input
```

Declare options as scalar values and use a boolean comparison in CEL:

```yaml
spec:
  fields:
    - name: enabled
      type: confirm
    - name: environment
      type: select
      options: [dev, prod]
      when: "answers.enabled == true"
```

## CI Validation

```yaml title=".github/workflows/validate-scaffolds.yml"
name: Validate scaffolds

on: [push, pull_request]

jobs:
  validate:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Validate templates
        run: |
          for manifest in scaffolds/*/scaffold.yaml; do
            atmos scaffold validate "$(dirname "$manifest")"
          done
```

Follow validation with a dry run and representative `--set` values:

```shell
atmos scaffold validate ./scaffolds/terraform-component
atmos scaffold generate ./scaffolds/terraform-component ./test-output \
  --defaults --set component_name=vpc --dry-run --skip-hooks
```

## Related Commands

- [`atmos scaffold generate`](/cli/commands/scaffold/generate)
- [Scaffold templates](/cli/commands/scaffold)
- [Workflow step types](/workflows/steps/type)