# Md Validation

> Use when validating markdown links or Mermaid diagrams.

- Skill: `haowjy/md-validation` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add haowjy/md-validation`
- Raw SKILL.md: https://api.skillmd.com/api/skills/haowjy/md-validation/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Docs & Writing
- Author: haowjy (https://skillmd.com/u/haowjy)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/haowjy/md-validation

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# md-validation

## Mermaid Diagrams

Validate Mermaid diagrams render correctly before shipping. Open the HTML
artifact in a browser and check every diagram visually — syntax errors show
as broken renders, not error messages.

Common failure modes:
- Unquoted labels with punctuation break the parse
- Bare lowercase `end` collides with subgraph terminator
- Node IDs starting with `o` or `x` after edge markers get misparsed
- Custom fills without matching text color make labels unreadable

See `resources/mermaid-authoring.md` for the full authoring rules (quoting,
line breaks, reserved words, themes).

## Markdown Links

Check that relative links between pages resolve. When building a multi-page
artifact or KB, broken cross-references silently rot — verify each link
target exists before committing.