@cartella/codes

Synchronous SVG generators for QR codes and barcodes. Deterministic, DOM-free, runs in Node / Edge / Workers / the browser.

Used by @cartella/renderer-html and @cartella/react to inflate QR and barcode layers into real visuals. Kept out of @cartella/core to keep core's runtime budget lean; consumers who want placeholder-only behavior can skip installing this package.

Install

pnpm add @cartella/codes

Usage

QR codes

import { qrToSvg } from '@cartella/codes';

const svg = qrToSvg('https://academia.example.com/v/STU-2026-0142', {
  errorCorrection: 'M', // L / M / Q / H (default M)
  size: 128,
  foreground: '#000000',
  background: '#ffffff',
  quietZone: 4,
});

Barcodes

import { barcodeToSvg } from '@cartella/codes';

const svg = barcodeToSvg('STU-2026-0142', 'code128', {
  barWidth: 0.5, // mm
  height: 15, // mm
  displayValue: true,
  foreground: '#000000',
  background: '#ffffff',
});

Supported formats: code128, code39, ean13, ean8, upc, itf14, datamatrix.

Why another codes package?

Parity. Cartella's editor and its server-side renderers share the same layerToHtml() function — so the QR/barcode output you see in the Studio must byte-identically match what the server prints. Both qrcode-svg and bwip-js produce deterministic SVG output with no randomness or floating-point noise, so the parity contract (0.1% pixel diff) holds end-to-end.

Determinism

Both helpers are pure:

• Same input → identical SVG bytes, every call
• No DOM, no network, no filesystem
• Safe to memoize by (value, options) tuple

Unit tests verify byte-identical output across multiple invocations.

License

MIT