@gum-jsx/node

The node runtime for gum.jsx: rasterizes the SVG that @gum-jsx/core produces to PNG with node-canvas, formats images for kitty-protocol terminals, and reads stdin. Browser hosts do not need this package — they inline the SVG directly.

Installation

npm install @gum-jsx/core @gum-jsx/node

Usage

import { evaluateGum } from '@gum-jsx/core/eval'
import { rasterizeSvg, rasterizePixels, formatImage } from '@gum-jsx/node'

const svg = evaluateGum('<Circle fill={blue} />', { size: 500 }).svg()
const png = rasterizeSvg(svg, { size: [ 500, 500 ], background: 'white' })   // Buffer
const pixels = rasterizePixels(svg)                                          // ImageData
process.stdout.write(formatImage(png))                                       // show in kitty/ghostty

rasterizeSvg(svg, { size?, background?, env? }) fits the SVG's own size into size (a number or [width, height]) and returns a PNG Buffer; rasterizePixels returns the raw ImageData instead. env is the Env whose fonts the SVG names (the default Env otherwise). formatImage(png, args) and formatPixels(pixels, [w, h], args) produce kitty graphics protocol escape sequences (imageId, placementId, columns, rows, cursorMovement, chunkSize). ansi(text, { fg, bg, bold, italic }) styles terminal text and readStdin() reads all of stdin.

The fonts the Env knows (IBM Plex and whatever plugins such as @gum-jsx/math add) are handed to node-canvas at rasterization, so <text> in the SVG resolves to the same faces that were measured. Emoji are not bundled: they are measured with a fixed advance and drawn with the system's emoji face (e.g. Noto Color Emoji) via fontconfig fallback.