A fast and type-safe ISO 8583 parser/encoder written in TypeScript, with strict LLVAR/LLLVAR enforcement, bitmap handling and built-in field level BCD/ASCII encoding.

🧰 Features

✔️ Type-safe message building & parsing
✔️ Field level BCD/ASCII encoding configuration
✔️ LLVAR / LLLVAR length enforcement
✔️ Bitmap parsing and generation
✔️ Dual build: ESM + CJS

🚀 Install

npm i @tikpay/iso8583-ts

📦 Usage

Import

import { Iso8583, N, AN, ANS, B, bitmap } from '@tikpay/iso8583-ts' //ESM

or

const { Iso8583, N, AN, ANS, B, bitmap } = require('@tikpay/iso8583-ts') //CJS

Define specification

import { AN, bitmap, LLVARn... } from '@tikpay/iso8583-ts'

export const sampleSpec: MessageSpec = {
  0: { name: 'MTI', format: N(4, { encoding: NumericEncoding.BCD }) }, //optional
  1: { name: 'Bitmap', format: bitmap(8) }, //optional
  2: {
    name: 'PAN',
    format: LLVARn({
      length: 19,
      lenHeader: VarLenHeaderEncoding.BCD,
      payload: VarPayloadEncoding.BCD_DIGITS,
      lenCountMode: VarLenCountMode.DIGITS,
    }),
  },
  22: { name: 'POSData', format: AN(12) },
  35: { name: 'Track2', format: LLVARans({ length: 37 }) },
}

Pack

const iso8583 = new Iso8583(sampleSpec)

const mti = '0200'
const paymentCall = {
  3: '000000',
  4: '00001000',
  11: '123456',
  12: '250910142500',
  22: '9010A0B00000',
  49: '036',
}

const { bytes, mti: packedMti } = iso8583.pack(mti, paymentCall)

Unpack

const iso8583 = new Iso8583(sampleSpec)

const decoded = iso8583.unpack(bytes)
console.log(decoded.mti) // '0200'
console.log(decoded.fields) // { 3: '000000', 4: '00001000', ... }

⭐ Inspiration

This library was inspired by excellent work from other ISO 8583 projects, including:

• @jpos/jPOS
• @zemuldo/iso_8583
• @micham/iso8583

📄 License

This project is licensed under the terms of the MIT open source license.