validate-frontmatter Claude Plugin

Validate YAML frontmatter in Claude Code skills, agents, and commands against official schema.

Installation

Add Sebastian's marketplace in Claude Code: /plugins -> Marketplaces -> Add

https://github.com/Sebastian80/sebastian-claude-marketplace.git

Install: /plugins -> Discover -> validate-frontmatter

Usage

# Validate single file
uv run --with pyyaml ~/.claude/plugins/cache/sebastian-marketplace/validate-frontmatter/*/skills/validate-frontmatter/scripts/validate.py path/to/file.md

# Validate all user components
uv run --with pyyaml ~/.claude/plugins/cache/sebastian-marketplace/validate-frontmatter/*/skills/validate-frontmatter/scripts/validate.py ~/.claude/

# CI mode
uv run --with pyyaml validate.py --json --strict .claude/

Options

Flag	Description
--json	Output JSON instead of human-readable
--strict	Treat warnings as errors (exit 1)
--type TYPE	Force component type (skill/agent/command)
--quiet	Only output errors/warnings

License

MIT