YAML Master
Proactive YAML intelligence: validate syntax, enforce consistent formatting, and keep configuration files schema-correct (Kubernetes, GitHub Actions, Docker Compose, and similar).
Overview
This skill activates when working with .yml/.yaml files to detect structural issues early (indentation, anchors, type mismatches), and to produce safe, minimal edits that keep CI/config tooling happy.
Prerequisites
- The YAML file(s) to inspect and their intended target (e.g., Kubernetes, GitHub Actions, Compose)
- Any relevant schema or constraints (when available)
- Permission to edit the file(s) (or to propose a patch)
Instructions
- Parse and validate YAML syntax (identify the first breaking error and its location).
- Normalize formatting (indentation, quoting) without changing semantics.
- Validate structure against the target system’s expectations (keys, types, required fields).
- Identify risky patterns (duplicate keys, ambiguous scalars, anchors used incorrectly).
- Output a minimal patch plus a short validation checklist (what to run next).
Output
- Corrected YAML with minimal diffs
- A concise list of issues found (syntax vs schema vs best practice)
- Follow-up validation commands appropriate for the target (e.g.,
kubectl apply --dry-run=client, CI lint)
Error Handling
- If the schema/target is unknown, ask for the target system and apply syntax-only fixes first.
- If the YAML is valid but tooling still fails, surface the exact downstream error and reconcile expectations.
Examples
Example: Fix an indentation/syntax error
- Input: a workflow with a mis-indented
steps:block. - Output: corrected indentation and a note on which job/step was affected.
Example: Convert JSON to YAML safely
- Input: a JSON config blob.
- Output: YAML with explicit quoting where necessary to avoid type surprises.
Resources
- Full detailed guide (kept for reference):
${CLAUDE_SKILL_DIR}/references/SKILL.full.md - YAML spec: https://yaml.org/spec/
- GitHub Actions workflow syntax: https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions