@paybysquare/core

Pay By Square payload generator — the Slovak Banking Association's payment QR standard. Zero runtime dependencies; pure TypeScript that runs in Node, browsers, and edge runtimes (no native modules, no WASM).

Part of the paybysquare/php multi-language suite: the same contract is implemented in PHP (paybysquare/php on Packagist, with a Laravel integration) and served by a hosted/self-hostable HTTP API — all verified against one shared set of test vectors.

Install

npm install @paybysquare/core

Usage

import { generatePayload } from '@paybysquare/core';

const payload = generatePayload({
  amount: 25.5,
  iban: 'SK7283300000009111111118',
  swift: 'FIOZSKBAXXX',
  variableSymbol: '2026001',
  beneficiaryName: 'Acme s.r.o.',
  note: 'Invoice FA20260103',
});
// payload is the string to put into a QR code

Pair it with any QR library, e.g. qrcode:

import QRCode from 'qrcode';

const dataUrl = await QRCode.toDataURL(generatePayload(payment));

Input

| Field | Required | Notes | |---|---|---| | amount | yes | positive, max 2 decimal places (not rounded — rejected) | | iban | yes | spaces allowed, case-insensitive | | beneficiaryName | yes | non-empty | | currency | no | ISO 4217, default EUR | | date | no | Date or 'YYYY-MM-DD', default today | | swift | no | 8 or 11 characters | | variableSymbol / specificSymbol | no | up to 10 digits | | constantSymbol | no | up to 4 digits | | note | no | up to 140 characters | | beneficiaryAddress1 / 2 | no | up to 70 characters |

Invalid input throws ValidationError with a field property naming the offending field.

Correctness

Every release passes the shared test vectors: payloads are decoded by an independent liblzma-based reference verifier and the recovered data must match the spec byte-for-byte. The LZMA stream this package emits is literal-coded — roughly 10–20% longer than liblzma's output (at most one QR version larger; scannability is unaffected) — and decodable by any conforming LZMA decoder.

Trademark note

PAY by square is a payment standard of the Slovak Banking Association. This is an independent open-source implementation, not affiliated with or endorsed by the SBA or Bysquare.

License

MIT © usmansher