@chromaglyph/node

napi-rs bindings for chromaglyph: compile syntax highlighting into an OpenType color font, in-process.

import { buildFontSafe } from '@chromaglyph/node'

const result = buildFontSafe({
  font: fontBytes,                       // static TTF / OTF (CFF) / WOFF1 / .ttc Buffer
  fontIndex: 0,                         // member of a .ttc collection (default 0)
  themes: ['dark-plus', 'light-plus'],   // builtin names or .json/.tmTheme paths
  blocks: [                              // batch any number of code blocks into ONE font
    { id: 'block-0', lang: 'rust', text: 'fn main() {}' },
    { id: 'block-1', lang: 'js', text: 'const x = 1' },
  ],
  verify: true,                          // harfrust oracle (default on)
  ligatures: true,                       // keep the font's != -> ligatures, highlighted
  format: 'woff2',                       // output container: 'woff' (default) | 'woff2'
  cacheDir: '.cache',                    // optional on-disk cache
})
// → { woff, ttf, css, themes, report, contentHash, cached }

• buildFont throws on invalid input; buildFontSafe returns null (silent degradation for build pipelines).
• Source fonts: static TrueType (TTF) and name-keyed CFF (OTF); WOFF1 containers and .ttc collections (fontIndex) are unwrapped, variable TrueType fonts are pinned to their default instance. CFF2 (variable OTF) and CID-keyed CFF are rejected with an explicit error.
• format: 'woff2' wraps the output in WOFF2 (Brotli, 15–30% smaller than the default WOFF1); result.woff then carries the WOFF2 bytes. Both outline flavors ride in it (TrueType as-is, CFF null-transform). The format is part of the content hash, so both variants cache independently.
• ligatures: true re-materializes the source font's ligatures (!=, ->) as build-time rules, so they render exactly as the font intends while staying highlighted; sites spanning multiple colors degrade to plain per-char text (colors win).
• generic: 'rust' | 'js' | 'ts' | 'python' | 'go' | 'java' builds a font that highlights ANY text of that language (keywords, comments, strings, numbers) — blocks and semantic are ignored in that mode.
• Artifacts are cached by content hash (font + theme sources + block texts
  • generic language + options): in-process LRU plus optional on-disk cache directory.
• One GSUB rule set serves every theme (CPAL palettes); switching is a CSS @font-palette-values flip.
• themes takes builtin names or paths. The builtins are shiki's tm-themes collection (64 themes, MIT/Apache-2.0 only); listThemes() returns the registry — name, displayName, type ('dark' | 'light'), license, source, foreground, background and per-scope swatches — enough to build a theme picker without compiling a font. tmThemesVersion() tells which collection version is embedded.

Build from source: pnpm --filter @chromaglyph/node build (requires Rust).