README.md

April 11, 2026 · View on GitHub

Lumis

Lumis Syntax Highlighter

lumis.sh - docs

Crates.io npm Hex.pm Maven Central License


Features

  • 110+ Tree-sitter languages - Fast, accurate, and updated syntax parsing
  • 250+ built-in Neovim themes - Updated and curated themes from the Neovim community
  • 6 runtimes - CLI, Rust, Elixir, JavaScript, Browsers / CDN, Java
  • Multiple outputs - HTML (inline/linked), Terminal (ANSI), Multi-theme (light/dark), BBCode, and custom formatters
  • Language auto-detection - File extension, shebang, and emacs-mode support
  • Streaming-friendly - Handles incomplete code
Ruby with Catppuccin Frappe theme SQL with GitHub Light theme

Quick Start

CLI

cargo install lumis-cli

lumis highlight app.js --theme dracula

Rust

use lumis::{highlight, HtmlInlineBuilder, languages::Language, themes};

let theme = themes::get("dracula").unwrap();

let formatter = HtmlInlineBuilder::new()
    .language(Language::Javascript)
    .theme(Some(theme))
    .build()
    .unwrap();

let html = highlight("const x = 1", formatter);

JavaScript

Works in JavaScript runtimes including Node.js, Bun, and Deno.

import { highlight } from '@lumis-sh/lumis'
import { htmlInline } from '@lumis-sh/lumis/formatters'
import javascript from '@lumis-sh/lumis/langs/javascript'
import dracula from '@lumis-sh/themes/dracula'

const html = await highlight('const x = 1', htmlInline({ language: javascript, theme: dracula }))

Browsers / CDN

Works in Browsers through bundlers or CDN imports.

import { highlight } from 'https://esm.sh/@lumis-sh/lumis'
import { htmlInline } from 'https://esm.sh/@lumis-sh/lumis/formatters'
import javascript from 'https://esm.sh/@lumis-sh/lumis/langs/javascript'
import dracula from 'https://esm.sh/@lumis-sh/themes/dracula'

const html = await highlight('const x = 1', htmlInline({ language: javascript, theme: dracula }))

Elixir

Lumis.highlight!("const x = 1", formatter: {:html_inline, language: "javascript", theme: "dracula"})

Java

By @andreaTP. More details at https://chicory.dev/blog/syntax-highlight

import io.roastedroot.lumis4j.core.Lumis;
import io.roastedroot.lumis4j.core.Lang;
import io.roastedroot.lumis4j.core.Theme;

var lumis = Lumis.builder().build();

var highlighter = lumis.highlighter()
    .withLang(Lang.JAVASCRIPT)
    .withTheme(Theme.DRACULA)
    .build();

var result = highlighter.highlight("const x = 1");
System.out.println(result.string());

Documentation

RuntimeInstallPackageDocs
CLIcargo install lumis-clicrates.io/lumis-cliREADME.md
Rustcargo add lumiscrates.io/lumisREADME.mddocs.rs
Elixir{:lumis, "~> 0.3"}hex.pm/lumisREADME.mdhexdocs
JavaScriptnpm install @lumis-sh/lumisnpmjs.com/@lumis-sh/lumisREADME.md
Browsers / CDNnpm install @lumis-sh/lumisnpmjs.com/@lumis-sh/lumisREADME.md
Javaio.roastedroot:lumis4j:0.0.7io.roastedroot/lumis4jREADME.md

Architecture

Every Lumis package is built around the same three pieces:

  • themes extracted from Neovim
  • languages backed by Tree-sitter grammars
  • formatters that turn highlighted tokens into output

Given some source code, Lumis parses it with the selected Tree-sitter language, resolves styles from the chosen theme, and then formats the highlighted result into HTML, ANSI, or any custom output.

WASM Versions

The npm WASM package versions follow the pattern <tree-sitter-version>.<seq> where:

  • tree-sitter-version is the major-minor version of the compatible Tree-sitter release
  • seq is a patch number for Lumis own updates

For example, @lumis-sh/wasm-rust@0.26.0 is the first published version compatible with Tree-sitter 0.26, while @lumis-sh/wasm-javascript@0.26.1 is a patch update compatible with Tree-sitter 0.26 (usually containing upstream parser updates).

Contributing

Contributions are welcome. Feel free to open issues or PRs for bugs, features, new themes, or languages.

See CONTRIBUTING.md

Acknowledgements

  • Makeup for setting up the baseline for the Elixir package
  • Inkjet for the Rust implementation in the initial versions
  • Shiki and syntect for the hard work defining how syntax highlighters should work

License

MIT