nyx

Tailwind CSS class formatter and linter. Canonicalizes non-standard class names and sorts classes using Tailwind's official ordering.

Built on top of @tailwindcss/oxide and the Tailwind v4 design system.

Install

npm install -g @rielj/nyx

Quick start

nyx init        # scaffold nyx.config.json
nyx check src/  # lint + format check
nyx check --fix src/  # auto-fix

Commands

nyx init

Create a nyx.config.json in the current directory with default settings:

nyx init

nyx check

Run both lint and format checks:

nyx check src/
nyx check --fix src/

nyx lint

Find non-canonical Tailwind classes (e.g. tw-bg-red-500 -> bg-red-500):

nyx lint src/
nyx lint --fix src/

nyx format

Sort Tailwind classes in the recommended order:

nyx format src/
nyx format --fix src/

Options

Flag	Description
--css <path>	Path to CSS entry point
--fix	Auto-fix issues
--strategy <name>	Sort strategy: tailwind (default) or alphabetical
--rem <px>	Root font size in px (default: 16)
--collapse	Collapse e.g. mt-2 mr-2 mb-2 ml-2 into m-2
--cache	Enable file-level caching to skip unchanged files
--json	Output diagnostics as JSON
--quiet	Only show summary
--verbose	Show full diagnostics in fix mode

Config file

Create a nyx.config.json in your project root (or run nyx init):

{
  "$schema": "./node_modules/@rielj/nyx/schema.json",
  "rem": 16,
  "collapse": false,
  "strategy": "tailwind"
}

Option	Type	Default	Description
css	string	auto-detect	Path to CSS entry point
rem	number	16	Root font size in px
collapse	boolean	false	Collapse longhand utilities into shorthand
strategy	"tailwind" | "alphabetical"	"tailwind"	Class sort strategy
cache	boolean	auto	Enable file-level caching (on by default when nyx is locally installed)

CLI flags override config file values.

Supported file types

.html, .jsx, .tsx, .vue, .svelte, .astro, .erb, .ejs, .hbs, .php, .blade.php, .twig, .njk, .liquid, .pug, .slim, .haml, .mdx, .md, .rs, .ex, .heex, .clj, .cljs

License

MIT