Tailwind Agents Validator

Tailwind Validator : Cross-Skill Consistency Agent

Acts as a Tailwind-specific code reviewer. Reads the codebase, runs every rule documented in the sibling skills, produces an actionable report that cites the authoritative source per finding.

The validator does NOT modify code. It reports. The developer (or a follow-up agent) applies fixes guided by the cited sibling skill.

How To Invoke

The user asks "validate my Tailwind code" or "audit this codebase for Tailwind issues" or "run a pre-PR check on the styling changes". The agent :

1. Detects v3 vs v4 (heuristic in Method 1, references/methods.md).
2. Runs each rule in the catalogue (Section : Rule Catalogue).
3. Emits the report in the standard format (Section : Report Format).

Detect : v3 or v4

Decision sources, in priority order :

1. package.json dependencies.tailwindcss semver. ^3.x is v3. ^4.x is v4.
2. CSS entry file contains @import "tailwindcss" (v4) OR three @tailwind directives (v3).
3. PostCSS config plugin is @tailwindcss/postcss (v4) OR tailwindcss (v3).
4. Vite config imports @tailwindcss/vite (v4) OR uses the PostCSS plugin (v3).

If signals conflict, report a Severity-Error mismatch FIRST. Mixed configurations produce silent failures.

Mixed-state cross-link : tailwind-impl-migration-v3-v4.

Rule Catalogue

Each rule names a check, the file types it scans, the sibling skill that documents the rule, and the severity.

Rule R-01 : No Dynamic Template-Literal Class Strings

Scans : .tsx, .jsx, .vue, .svelte, .astro, .mdx

Detect : grep for className=`...${...}...` and class="...{{ ...?... }}...{{ ... }}" patterns that build a class fragment from a variable.

Severity : Error (production bug, classes silently missing)

Sibling skill : tailwind-errors-dynamic-classes

Fix : static map per Method 1 of the sibling skill.

Rule R-02 : Scoped @apply Without @reference (v4 only)

Scans : .vue, .svelte, *.module.css

Detect : file contains @apply inside a scoped <style> block or a CSS module, and the same block does NOT contain @reference.

Severity : Error (build fails with "Cannot apply unknown utility class")

Sibling skill : tailwind-impl-apply-directive

Fix : prepend @reference "../path/to/app.css"; inside the style block.

Rule R-03 : Forbidden v3 Config Keys in v4 Project

Scans : tailwind.config.js, tailwind.config.ts

Detect : project is v4 AND config file contains any of corePlugins, safelist, separator.

Severity : Warning (silently ignored, original intent lost)

Sibling skill : tailwind-errors-v4-migration, fallback to tailwind-impl-migration-v3-v4

Fix :

• corePlugins : remove and replace with ESLint rule or @source not
• safelist : convert to @source inline("...") in CSS
• separator : remove ; v4 fixes separator to :

Rule R-04 : Undefined Custom Class Outside @layer

Scans : .css

Detect : project is v3 and file contains a custom class declaration (.classname { ... }) outside @layer base / @layer components / @layer utilities. Project is v4 and file contains a custom class without @utility or @layer.

Severity : Warning (cascade ordering unpredictable, overrides behave inconsistently)

Sibling skill : tailwind-impl-config-v3, tailwind-impl-config-v4

Fix : wrap in @layer components (v3) or rewrite as @utility (v4).

Rule R-05 : Variant Stack Order

Scans : .tsx, .jsx, .vue, .svelte, .html

Detect : v4 project contains a class with two or more variants that look v3-style. Common patterns : first:*:, last:*:, hover:lg: (the lg should come first under v4 left-to-right rule for breakpoints AT the variant level).

Severity : Warning (visual regression after v3 to v4)

Sibling skill : tailwind-syntax-variants, tailwind-impl-migration-v3-v4

Fix : flip the order. first:*:pt-0 becomes *:first:pt-0.

Rule R-06 : Bare border / ring / placeholder Under v4

Scans : .tsx, .jsx, .vue, .svelte, .html

Detect : v4 project AND class list contains a bare border, ring, placeholder token with no following colour or width modifier on the same element.

Severity : Info (visual regression risk : default colour changed from gray-200 / blue-500 / gray-400 to currentColor)

Sibling skill : tailwind-errors-v4-migration, tailwind-impl-migration-v3-v4

Fix : add explicit colour (border-zinc-200, ring-blue-500, placeholder-zinc-400) OR restore v3 defaults globally via @layer base (see method).

Rule R-07 : Em-Dash in User-Facing String

Scans : .tsx, .jsx, .vue, .svelte, .html, .mdx

Detect : literal — (U+2014) inside JSX text, attribute strings that render to users (title, aria-label, placeholder), or component children.

Severity : Info (typography standard ; CLAUDE.md project rule)

Sibling skill : (project rule, see workspace CLAUDE.md)

Fix : replace with ., ,, or rewrite the sentence. NEVER replace with -.

Rule R-08 : Deterministic Prop-to-Class Mapping

Scans : .tsx, .jsx, .vue, .svelte

Detect : component receives a variant / color / size prop and constructs the class via a switch statement, ternary chain, or function call that returns differently-shaped strings per branch.

Severity : Info (maintainability ; not a bug, but harder to audit)

Sibling skill : tailwind-core-design-system

Fix : refactor to a single object literal mapping prop value to complete class string.

Rule R-09 : twMerge Order Mistake

Scans : .tsx, .jsx, .vue, .svelte

Detect : twMerge(...) or cn(...) call with conflicting utilities where the LATER argument is the loser (e.g. twMerge('p-4', 'p-2') resolves to p-2 ; if the intent was p-4 as the override, the argument order is wrong).

Severity : Info (requires intent inference ; flag for human review only)

Sibling skill : tailwind-impl-tailwind-merge

Fix : reverse the argument order so the override is last.

Rule R-10 : Plugin Missing Default Theme Values

Scans : *.js, *.ts files exporting a Tailwind plugin

Detect : the plugin body calls theme('someNamespace') AND the plugin's second-arg config does NOT define theme.extend.someNamespace.

Severity : Warning (plugin works only when consumer happens to configure the namespace, fails silently otherwise)

Sibling skill : tailwind-impl-plugins-custom

Fix : ship defaults via the plugin(fn, { theme: { ... } }) second argument.

Report Format

Tailwind Validator Report
=========================
Project state : v4 detected (tailwindcss@^4.0.5)
Scan scope    : src/ tests/ tailwind.config.js postcss.config.mjs
Files scanned : 412
Issues        : 7 (1 error, 3 warnings, 3 info)

---

[ERROR] R-01 : dynamic class string
  File       : src/components/Tag.tsx:14
  Code       : `className={`bg-${color}-100 text-${color}-800`}`
  Cite       : tailwind-errors-dynamic-classes (Fix 1, static map)
  Suggested  : replace with lookup object indexed by `color`.

[ERROR] R-02 : scoped @apply without @reference
  File       : src/components/Hero.vue:42
  Block      : <style scoped> @apply text-2xl font-bold </style>
  Cite       : tailwind-impl-apply-directive
  Suggested  : prepend `@reference "../app.css";` inside <style>.

[WARNING] R-03 : forbidden v3 key in v4 config
  File       : tailwind.config.js:8
  Key        : safelist
  Cite       : tailwind-impl-migration-v3-v4 (Method 7)
  Suggested  : move to `@source inline(...)` in src/app.css and
               remove from JS config.

... etc

Per-issue fields :

• Severity tag in brackets
• Rule code
• File and line number
• The offending snippet
• The sibling skill name (NOT a URL ; the in-package skill reference)
• A one-line suggested fix

Cross-Reference Index

CI Integration

The validator is ADVISORY by default. Exit code is 0 unless errors exceed the configured threshold. Sample GitHub Actions step :

- name: Tailwind audit
  run: |
    claude --skill tailwind-agents-validator . > tailwind-report.txt
    cat tailwind-report.txt
    # fail only if errors > 0
    grep -q '^\[ERROR\]' tailwind-report.txt && exit 1 || exit 0

NEVER block PRs on info or warning levels. Errors (R-01, R-02) indicate real production bugs and SHOULD block.

Sequencing With Sibling Skills

The validator is NOT a substitute for the per-area skills. When a finding cites tailwind-errors-dynamic-classes, the developer (or the follow-up agent) opens that skill for the full fix catalogue.

Recommended workflow :

1. Run tailwind-agents-validator.
2. For each error : open the cited skill, apply the documented fix.
3. Re-run the validator. Iterate until errors = 0.
4. Optional : address warnings and info as time allows.

References

• references/methods.md : per-rule detection commands (grep, AST, PostCSS) and the v3-or-v4 heuristic in detail
• references/examples.md : sample input codebase plus the validator report it should produce
• references/anti-patterns.md : ten high-impact violations the validator catches, with before/after

Sources

• All sibling skills in this package
• Project CLAUDE.md (workspace conventions)