{"id":27160,"library":"muro-css","title":"Muro CSS (.mss preprocessor)","description":"A TypeScript CSS preprocessor and bundler for .mss files. Current stable version is 26.0.2. Actively maintained with regular releases. Compiles a single entry file or an entire directory of .mss sources into one CSS output. Supports variables, nesting, mixins, imports (including built-in modules like muro:reset), conditionals, loops, theme baking (light/dark), semantic layering, guard locks, and automatic raster asset rewriting to webp. Includes CLI with watch, minify, purge, sourcemap, and asset-dir options. Ships TypeScript types. Differentiators: designed as a TypeScript-first alternative to Sass/PostCSS with built-in utilities and zero-config polyfilling.","status":"active","version":"26.0.2","language":"javascript","source_language":"en","source_url":"https://github.com/isaacmuliro/xerxisfy-elite-style-sheet","tags":["javascript","muro","mss","x2s","css","compiler","preprocessor","bundler","sass","typescript"],"install":[{"cmd":"npm install muro-css","lang":"bash","label":"npm"},{"cmd":"yarn add muro-css","lang":"bash","label":"yarn"},{"cmd":"pnpm add muro-css","lang":"bash","label":"pnpm"}],"dependencies":[],"imports":[{"note":"ESM-only; package.json type is module. Ships types.","wrong":"const muro = require('muro-css')","symbol":"default","correct":"import muro from 'muro-css'"},{"note":"Named export for programmatic use. Available since v26.","wrong":"import compile from 'muro-css/compile'","symbol":"compile","correct":"import { compile } from 'muro-css'"},{"note":"Type-only import; MuroOptions is an interface, not a value.","wrong":"import { MuroOptions } from 'muro-css'","symbol":"MuroOptions","correct":"import type { MuroOptions } from 'muro-css'"}],"quickstart":{"code":"// app.mss\n$primary: #224466;\n\n.button {\n  color: $primary;\n  &:hover {\n    color: darken($primary, 10%);\n  }\n}\n\n// Install: npm i -D muro-css\n// Run: muro app.mss app.css\n\n// Programmatic usage in Node.js >=18\nimport { compile } from 'muro-css';\n\nconst result = compile({\n  input: 'styles.mss',\n  output: 'styles.css',\n  sourcemap: true,\n});\n\nconsole.log('CSS compiled:', result.css);","lang":"typescript","description":"Compiles an .mss file to CSS using CLI and programmatic API with TypeScript types."},"warnings":[{"fix":"Rename .x2s files to .mss and replace x2s:*/@x2s/* imports with muro:* equivalents.","message":"Since v26, legacy .x2s files and imports (x2s:*, @x2s/*) are deprecated and will be removed in the next major version.","severity":"breaking","affected_versions":">=26.0.0"},{"fix":"Upgrade Node.js to version 18 or later.","message":"Node.js >=18 required in v26. Older Node versions will fail.","severity":"breaking","affected_versions":">=26.0.0"},{"fix":"Use muro CLI and muro: built-in imports instead.","message":"The x2s CLI alias and x2s: built-in imports are deprecated in v26 and will be removed next release.","severity":"deprecated","affected_versions":">=26.0.0 <27.0.0"},{"fix":"Use @import 'muro:reset' for built-in, or @import './partial.mss' for files.","message":"When using @import in .mss files, paths beginning with 'muro:' refer to built-in modules. Other relative paths must include the file extension.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Avoid putting space before # for comments; use // or ** for safer comment syntax.","message":"The # character at line start is treated as a comment only if it's the first non-whitespace character. Hex colors and ID selectors like #hero work normally.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Ensure a .webp converter (e.g., cwebp) is available in PATH, or use --no-assets to skip rewriting.","message":"Automatic raster asset rewriting to .webp requires an external converter to be installed on the system. Without it, assets are left as-is.","severity":"gotcha","affected_versions":">=26.0.0"}],"env_vars":null,"search_vec":"'26.0.2':18 'activ':19 'altern':91 'asset':65,78 'asset-dir':77 'automat':63 'bake':56 'built':47,96 'built-in':46,95 'bundler':10,111 'cli':70 'compil':24,109 'condit':53 'config':102 'css':2,7,38,108 'current':14 'design':85 'differenti':84 'dir':79 'directori':32 'entir':31 'entri':27 'file':13,28 'first':90 'guard':60 'import':44 'includ':45,69 'javascript':104 'layer':59 'light/dark':57 'like':50 'lock':61 'loop':54 'maintain':20 'minifi':73 'mixin':43 'modul':49 'mss':3,12,34,106 'muro':1,51,105 'nest':42 'one':37 'option':80 'output':39 'polyfil':103 'preprocessor':4,8,110 'purg':74 'raster':64 'regular':22 'releas':23 'reset':52 'rewrit':66 'sass':112 'sass/postcss':93 'semant':58 'ship':81 'singl':26 'sourc':35 'sourcemap':75 'stabl':15 'support':40 'theme':55 'type':83 'typescript':6,82,89,113 'typescript-first':88 'util':98 'variabl':41 'version':16 'watch':72 'webp':68 'x2s':107 'zero':101 'zero-config':100","created_at":"2026-05-01T17:44:49.694688+00:00","updated_at":"2026-05-01T17:44:49.694688+00:00","problems":[{"fix":"Run 'npm i muro-css' or 'npm i -D muro-css' to install.","cause":"Package not installed in node_modules.","error":"Error: Cannot find module 'muro-css'"},{"fix":"Use import { compile } from 'muro-css'.","cause":"Incorrect import path or using default import when import { compile } is required.","error":"TypeError: compile is not a function"},{"fix":"Ensure # comments start at line beginning; use // for inline comments.","cause":"A # comment is placed after non-whitespace on a line, or hex color/scss syntax is mistakenly treated.","error":"SyntaxError: Unexpected token '#'"}],"ecosystem":"npm","meta_description":null,"install_score":null,"quickstart_score":null,"quickstart_tag":null,"pypi_latest":null,"cli_name":"muro","cli_version":null,"type":"library","homepage":null,"github":"https://github.com/isaacmuliro/xerxisfy-elite-style-sheet","docs":null,"changelog":null,"pypi":null,"npm":"https://www.npmjs.com/package/muro-css","openapi_spec":null,"status_page":null,"smithery":null,"categories":["web-framework"],"base_url":null,"auth_type":null,"provenance":{"verified_status":null,"verified_at":null,"last_verified":"2026-04-25","next_check":"2026-07-24","install_tag":null}}