Show HN: Sasso – pure-Rust SCSS compiler, byte-exact to current dart-sass
Sasso is a new pure-Rust SCSS compiler that outputs byte-exact CSS matching dart-sass. It has zero dependencies, supports WebAssembly, and offers both a library and CLI interface.
Background
- Sasso is an open-source SCSS compiler written entirely in Rust — the goal is to produce byte-identical CSS output to the official Dart-based Sass compiler (dart-sass).
- SCSS (Sassy CSS) is the most widely used extension of standard CSS, adding variables, nesting, mixins, and other programming-like features to make stylesheets more maintainable.
- Dart-sass is the reference implementation maintained by the Sass team, but it requires the Dart runtime, which is a dependency that many build toolchains (especially in the Rust or WebAssembly ecosystem) would rather avoid.
- This project offers a drop-in replacement in Rust with zero external dependencies and WebAssembly compatibility, making it easier to integrate into Rust tooling (e.g., bundlers like Trunk) or WASM-based workflows without pulling in a Dart interpreter.