A stylelint custom rule that asserts every file begins with a configured header comment — typically a copyright or licence notice. When the header is missing, the rule reports an error; with --fix, it prepends the header for you.

The problem

Copyright and licence headers are easy to add and easy to forget. A pre-commit lint check is the natural place to enforce them, but stylelint doesn't ship a header rule out of the box. stylelint-header bridges the gap — point it at a string or a file and every CSS/SCSS/Less file in your project picks up the same header, formatted consistently, with --fix doing the boring work.

Features

• Template-driven — pass a string or a path to a file; supports lodash.template syntax for variables
• Fuzzy matching — uses string-similarity so cosmetic edits (whitespace, year bumps) don't trigger false positives
• Auto-fixable — missing headers are prepended on --fix, preserving the rest of the file
• Minifier-friendly — opt into /*! syntax so the header survives tools like cssnano
• Built-in variables — YEAR, FILE_NAME, and FILE_PATH are filled in automatically; bring your own as needed

Installation

yarn add --dev @allons-y/stylelint-header
npm install --save-dev @allons-y/stylelint-header
pnpm add --save-dev @allons-y/stylelint-header
bun add --dev @allons-y/stylelint-header

Usage

Add the plugin to your stylelint config and enable the header/header rule, passing either a string template or a path to a file containing the template. To toggle the rule off, set the value to null.

With a template file

{
	"plugins": ["@allons-y/stylelint-header"],
	"rules": {
		"header/header": ["./COPYRIGHT"]
	}
}

With an inline template string

{
  "plugins": ["@allons-y/stylelint-header"],
  "rules": {
    "header/header": [
      "Copyright <%= YEAR %>. <%= company %>",
      {
        templateVariables: {
          company: "AI Overlords Inc.",
        },
        nonMatchingTolerance: 0.8,
      },
    ],
  },
}

Options

templateVariables

Type: object   Default: {}

Key/value pairs used to substitute variables in the header template. Given a template like:

(c) <%= YEAR %> <%= company %>

and a config of:

{
  templateVariables: {
    company: "AI Overlords Inc.",
  },
}

the resulting header becomes:

/*!
 * (c) 2026 AI Overlords Inc.
 */

YEAR was substituted automatically — it doesn't need to appear in templateVariables. The following variables are always available:

| Variable | Value | | ----------- | -------------------------------- | | YEAR | The current year | | FILE_NAME | The basename of the linted file | | FILE_PATH | The directory of the linted file |

Templates use lodash.template — see the lodash docs for the full syntax.

nonMatchingTolerance

Type: number between 0 and 1   Default: 0.98

Minimum similarity (per string-similarity) between the comment found at the top of the file and the configured header. Lower the value when you want to allow small drift (e.g. a stale year); raise it to enforce an exact match.

isRemovable

Type: boolean   Default: false

When true, generated headers begin with /* rather than /*!. The /*! prefix is preserved by most CSS minifiers (e.g. cssnano) — leave the default in place if you want the header to survive minification, set to true if you don't.

Requirements

• Node.js >= 24
• stylelint 17.x

Contributing

Contributions are welcome — see CONTRIBUTING.md for the full workflow, and CODE_OF_CONDUCT.md for community expectations. For bugs and ideas, please open an issue.

This project is licensed under the MPL-2.0 License - see the LICENSE file for details. This means you can use this freely, modify as needed; changes to MPL-licensed files should be shared back under the same license.

If you find this plugin useful and would like to buy me a coffee/beer as a small thank you, I would greatly appreciate it!