| name | design-md-validator |
| description | Validate DESIGN.md files against the official Google specification using the `@google/design.md` CLI linter. Works with local files and remote URLs. Use when the user wants to lint a DESIGN.md, check spec compliance, find broken token references, verify WCAG contrast ratios, diff two versions, export tokens to Tailwind or DTCG format, or audit a design system file for structural correctness. Trigger on mentions of "validate DESIGN.md", "lint DESIGN.md", "check my design.md", "design.md spec compliance", "WCAG contrast check", "broken token references", "design token validation", "export design tokens", "diff design systems", "design.md audit", "@google/design.md", "npx design.md lint", "design system validation", "frontmatter tokens", or any request to verify a DESIGN.md file.
|
| metadata | {"author":"https://ft.ia.br","version":"1.1","date":"2026-07-18T00:00:00.000Z","repository":"https://github.com/fabricioctelles/skills","license":"Apache 2.0","category":"product-verification","upstream":{"spec":"https://github.com/google-labs-code/design.md","cli":"https://www.npmjs.com/package/@google/design.md","stitch-skills":"https://github.com/google-labs-code/stitch-skills"}} |
design-md-validator
Validate, lint, diff, and export DESIGN.md files using the official Google
@google/design.md CLI. Always uses the latest published version from npm —
no vendored copy, always up-to-date with the spec.
When to Use
| Trigger | Action |
|---|
| User has a DESIGN.md file and wants validation | lint |
| User wants to compare two versions | diff |
| User wants to export tokens to Tailwind/DTCG | export |
| User wants to see the current spec | spec |
| User shares a URL to a raw DESIGN.md | Fetch → lint |
| User asks "is my design.md valid?" | lint + interpret findings |
Core Commands
All commands use npx @google/design.md to ensure the latest version is always
used. Never install globally — npx resolves from the public npm registry.
Lint (validate)
npx @google/design.md lint DESIGN.md
Output: JSON with findings[] and summary { errors, warnings, infos }.
Exit code 1 if errors found, 0 otherwise.
Diff (compare versions)
npx @google/design.md diff DESIGN.md DESIGN-v2.md
Output: JSON with token-level changes (added, removed, modified) and regression flag.
Exit codes: 0 no regression, 1 regression (errors in "after" > errors in "before"),
2 input failure (file not found or unreadable).
Export (to other formats)
npx @google/design.md export --format json-tailwind DESIGN.md
npx @google/design.md export --format css-tailwind DESIGN.md
npx @google/design.md export --format dtcg DESIGN.md
npx @google/design.md export --format css-vars DESIGN.md
npx @google/design.md export --format css-vars --prefix ds DESIGN.md
css-vars is available on main, ships in the next release — if the CLI
rejects the format, npm is still on 0.3.0.
Spec (output the format specification)
npx @google/design.md spec
npx @google/design.md spec --rules
npx @google/design.md spec --rules-only --format json
Workflow
1. Obtain the DESIGN.md
Local file:
npx @google/design.md lint ./DESIGN.md
From URL (fetch first):
curl -sL <url> > /tmp/DESIGN.md && npx @google/design.md lint /tmp/DESIGN.md
From stdin:
cat DESIGN.md | npx @google/design.md lint -
2. Discover the Active Rule Set
Before interpreting anything, check which rules the installed CLI actually
runs — the rule set changes between releases, and the bundled references are
a fallback, not the authoritative source:
npx @google/design.md spec --rules-only --format json
3. Run Lint
npx @google/design.md lint --format json DESIGN.md
4. Interpret Findings
Parse the JSON output and report to the user:
| Severity | Meaning | Action |
|---|
error | Spec violation — file is invalid | Must fix |
warning | Best practice violation — file is valid but suboptimal | Should fix |
info | Informational — suggestions for improvement | Nice to fix |
5. Provide Actionable Fixes
For each finding, explain:
- What the rule checks
- Why it matters
- How to fix it with a concrete code example
6. Re-validate After Fixes
After applying fixes, re-run lint to confirm the file passes.
Linting Rules Reference
Load references/linting-rules.md for the complete rule table when providing
detailed explanations of lint failures.
Token Schema Quick Reference
Load references/token-schema.md for the complete YAML frontmatter schema
when helping users author or fix their frontmatter tokens.
Windows Compatibility
On Windows/PowerShell, the .md suffix in the bin name collides with Markdown
file associations. Use the designmd alias:
npx -p @google/design.md designmd lint DESIGN.md
Related Official Skills
| Skill | Source | Purpose |
|---|
stitch-design-taste | google-labs-code/stitch-skills | Generates DESIGN.md for Google Stitch |
design-md (Stitch plugin) | google-labs-code/stitch-skills | Analyzes Stitch projects → DESIGN.md |
taste-design (MCP) | mcpservers.org | MCP server for Stitch design extraction |
Install the official Stitch skill for generation:
npx skills add https://github.com/google-labs-code/stitch-skills --skill design-md
Anti-Patterns
- Never vendor or cache the CLI — always use
npx for latest spec
- Never manually parse YAML frontmatter when the linter can do it
- Never guess at contrast ratios — let the linter compute them
- Never assume section order is correct — let the linter verify
- Never skip re-validation after fixes
- Never assume the rule set from memory or from the bundled references —
confirm it at runtime with
spec --rules-only
Example Session
User: validate my DESIGN.md
Agent:
1. Reads the file
2. Runs: npx @google/design.md spec --rules-only --format json
3. Runs: npx @google/design.md lint --format json DESIGN.md
4. Parses output
5. Reports:
- summary: { errors: 0, warnings: 2, infos: 1 }
- WARNING: contrast-ratio — button textColor on backgroundColor is 3.8:1 (needs 4.5:1)
- WARNING: orphaned-tokens — color "accent-muted" defined but never used
- INFO: token-summary — 5 colors, 3 typography, 2 rounded, 2 spacing
6. Suggests fixes with code
7. Re-runs lint to confirm
