# Frontmatter Guard

> Injects the canonical vault frontmatter schema snippet into agent prompts before any vault-write task, preventing malformed YAML frontmatter in Obsidian notes. <example>Context: wave-executor is about to dispatch a vault-mirror agent that writes learning notes under ~/Projects/vault/40-learnings/. user: "dispatch vault-write agent" assistant: "Injecting frontmatter-guard snippet into agent prompt (vault scope detected). Required fields: id, type, created, updated. Enum type: note|daily|project|person|reference|idea|learning|session." <commentary>The wave-executor pre-dispatch hook calls detectVaultTaskScope() — the fileScope contains /Projects/vault/40-learnings/ so the guard triggers and the snippet is prepended to the agent system prompt.</commentary></example>

- Skill: `kanevry/frontmatter-guard-3` (Agent Skill)
- Install (CLI): `npx skillmds@latest add kanevry/frontmatter-guard-3`
- Raw SKILL.md: https://api.skillmd.com/api/skills/kanevry/frontmatter-guard-3/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: Kanevry (https://skillmd.com/u/kanevry)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/kanevry/frontmatter-guard-3

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# frontmatter-guard

> **Portable mirror — generated, do not edit.** The canonical skill body lives at
> [`skills/frontmatter-guard/SKILL.md`](../../../skills/frontmatter-guard/SKILL.md); read that file for the full instructions.
> This mirror carries only agentskills.io-spec-legal frontmatter so harnesses that
> discover skills under `.agents/skills/` can find and route to the skill.
>
> Regenerate with `node scripts/generate-agents-skills.mjs`.