Builder API

@qrcodesdk/core is the foundation of QRCodeSDK. It turns data into a QR code matrix and lets renderers decide how that matrix becomes SVG, terminal text, PNG, DOM output, or any custom format.

Install it when you need:

• qrcode() and the immutable builder API
• SVG output
• terminal text output
• matrix output
• custom renderers

Builder API

Start with qrcode() and chain the options you need.

import {SVGQRCodeRenderer, qrcode} from '@qrcodesdk/core';

const svg = qrcode('https://qrcodesdk.dev')
  .mode('octet')
  .errorCorrection('M')
  .version(4)
  .mask(2)
  .renderer(SVGQRCodeRenderer())
  .render();

You can also create the builder first and provide data later.

import {QRCodeTextRenderer, qrcode} from '@qrcodesdk/core';

const terminalRenderer = QRCodeTextRenderer({size: 1, margin: 2});

const output = qrcode()
  .data('HELLO WORLD')
  .mode('alphanumeric')
  .renderer(terminalRenderer)
  .render();

Data

QRCodeSDK accepts string and number input.

qrcode('https://qrcodesdk.dev');
qrcode(1234567890);

Use a mode when you know the shape of your data.

Mode	Best for
numeric	Digits only.
alphanumeric	Uppercase QR alphanumeric data such as HELLO WORLD.
octet	UTF-8 text, URLs, JSON, emoji, and general byte data.

If you do not provide a mode, the builder resolves one from the input.

Methods

The builder is immutable. Each method returns a new builder with the updated option.

Method	Description
.data(value)	Sets QR input data.
.mode(mode)	Sets the mode: numeric, alphanumeric, or octet.
.errorCorrection(level)	Sets the error correction level: L, M, Q, or H. Defaults to M.
.version(version)	Pins a QR version from 1 to 40.
.mask(mask)	Pins a mask from 0 to 7.
.matrix()	Returns the generated QRCodeMatrix.
.renderer(renderer)	Stores a renderer for a later .render() call.
.render(renderer?)	Generates the matrix and returns renderer output.

Error correction

The default error correction level is M.

qrcode('https://qrcodesdk.dev').errorCorrection('H');

Available levels are L, M, Q, and H. Higher levels can survive more damage, but they reduce capacity and can require a larger QR version.

Version and mask

Most applications should let the builder choose the version and mask automatically.

const matrix = qrcode('HELLO WORLD').mode('alphanumeric').version(1).mask(2).matrix();

Versions range from 1 to 40. Masks range from 0 to 7.

Matrix output

Use .matrix() when you want to build your own renderer or inspect the QR code directly.

import {type QRCodeMatrix, qrcode} from '@qrcodesdk/core';

const matrix: QRCodeMatrix = qrcode('custom renderer').matrix();

A matrix is a two-dimensional array of modules. 1 means dark and 0 means light.

Custom renderers

A renderer is a function that receives a matrix and returns any output type.

import {type QRCodeRenderer, qrcode} from '@qrcodesdk/core';

const jsonRenderer: QRCodeRenderer<string> = (matrix) =>
  JSON.stringify({size: matrix.length, matrix});

const json = qrcode('renderer output').render(jsonRenderer);

Renderers can be passed directly to .render(renderer) or stored with .renderer(renderer).render().

Built-in core renderers

@qrcodesdk/core includes runtime-neutral renderers:

• Render SVG
• Render Terminal Text

For runtime-specific output, add:

• @qrcodesdk/node for PNG buffers
• @qrcodesdk/browser for Canvas and Image elements