Skill: Config Validation

Purpose

Validate Home Assistant YAML configurations for syntax, structure, and best practices before applying changes.

When to Use

• Writing or modifying any YAML config file
• Before suggesting changes to packages/ files
• When the user asks "does this look right?" or "validate my config"
• After any automation or integration change

Steps

1. Identify target file — Determine which package file is being modified
2. Check YAML syntax — Validate indentation, quoting, special characters
3. Verify entity references — Ensure entity_id, device_id, area_id references exist
4. Check for duplicates — No duplicate entity IDs, automation aliases, or service calls
5. Validate structure — Ensure top-level keys match HA schema (light, sensor, automation, etc.)
6. Review secrets usage — Flag any hardcoded credentials
7. Report findings — List issues by severity (error, warning, info)

Common Validation Checks

Check	Severity	Example
Indentation	Error	Mixed tabs/spaces, wrong indent level
Duplicate entity_id	Error	Two entities with same ID
Missing required field	Error	action: without a service/action value
Legacy automation keys	Error	trigger:/action:/condition:/service:/platform: (use triggers/actions/conditions/action/trigger)
Invalid entity reference	Warning	entity_id: light.nonexistent
Hardcoded secret	Warning	api_key: "my-secret-key" instead of !secret
Deprecated option	Info	Using old-style latitude: instead of recorder: config
Missing description	Info	Automation without description: field

Output Format

Validation Results for packages/areas/kitchen.yaml:

❌ ERROR (line 12): Duplicate entity_id 'light_kitchen_counter'
⚠️  WARNING (line 28): Hardcoded API key found, use !secret
ℹ️  INFO: Automation missing 'description' field

Tools

• POST /api/config/core/check_config — Home Assistant config validator (Bearer token)
• Developer Tools → YAML — UI config check / reload
• yamllint — External YAML linting tool
• pre-commit — Git hook for pre-commit validation

Notes

• This skill is procedural — it guides the agent through validation, not code
• Always validate in the context of the full configuration, not just the modified file
• Entity references may be defined in other packages — check across packages/