A cross-platform BER-TLV / TLV parser for EMV payment systems.

Parse, explain, and visualize EMV BER-TLV data on any platform — Web, Android, iOS, and JVM — from a single Kotlin Multiplatform core.

Universal BERTLV provides:

• Full BER-TLV parsing — recursive decode of constructed and primitive tags
• Hex string input — parse or build TLVs directly from hex strings (whitespace is ignored)
• EMV tag dictionary — all EMV 4.1 tags with human-readable names
• Value explainers — bitfield, lookup, and complex explainers for 30+ EMV tags (TVR, AIP, CVM List, IACs, country/currency codes, and more)
• Cross-platform — one Kotlin Multiplatform library powers every target

┌─────────────────────────────────────────────┐
│                  Your App                   │
│            (Flutter / Kotlin)               │
├─────────────────────────────────────────────┤
│          plugin/ — Flutter Plugin           │
│  ┌─────────────┐  ┌──────────────────────┐  │
│  │ universal_bertlv  │  │  Platform packages   │  │
│  │ (interface) │  │  _web  │  _mobile    │  │
│  └─────────────┘  └──────────────────────┘  │
├─────────────────────────────────────────────┤
│        lib/ — Kotlin Multiplatform          │
│           universal-bertlv (core)                 │
│      JS • JVM • Android • iOS (Native)     │
└─────────────────────────────────────────────┘

The Flutter packages are not yet published to pub.dev. Consume a tagged source release and declare the app-facing package plus the required platform package:

dependencies:
  universal_bertlv:
    git:
      url: https://github.com/rafaelrabeloit/universal-bertlv.git
      ref: v0.0.10
      path: plugin/universal_bertlv
  universal_bertlv_web:
    git:
      url: https://github.com/rafaelrabeloit/universal-bertlv.git
      ref: v0.0.10
      path: plugin/universal_bertlv_web

For Android/iOS, replace universal_bertlv_web with universal_bertlv_mobile.

// build.gradle.kts
implementation("io.github.rafaelrabeloit:universal-bertlv:0.0.10")

GitHub Packages is also available for snapshot builds — see lib/universal-bertlv/build.gradle.kts.

import 'package:universal_bertlv/universal_bertlv.dart';

final parser = BertlvEmv();
final result = await parser.parse('6F1A840E315041592E5359532E4444463031A5088801025F2D02656E');

for (final tag in result.tags) {
  print('${tag.hexTag}: ${tag.name} = ${tag.hexValue}');
}

Parse a TLV list from hex:

import io.github.rafaelrabeloit.bertlv.TLV
import io.github.rafaelrabeloit.bertlv.TLVList
import io.github.rafaelrabeloit.bertlv.TlvFindMode
import io.github.rafaelrabeloit.emv.EmvSpecification

val tlvList = TLVList.fromTlvListBuffer(
    "6F1A840E315041592E5359532E4444463031A5088801025F2D02656E",
    listOf(EmvSpecification),
)

tlvList.tlvs.forEach { println("${it.tag.toString(16).uppercase()}: ${it.hexValue}") }

Parse or build a single TLV:

// Parse complete TLV from hex (spaces allowed)
val aid = TLV.fromBinaryTlvBuffer("9F06 07 A0000000031010")
println(aid.hexValue) // A0000000031010

// Build from tag + value hex
val built = TLV.fromTagAndBinaryValue(0x9F06, "A0000000031010")

// Find a tag inside a TLV list
val tvr = tlvList.find(0x95, TlvFindMode.FIRST)
val duplicateSensitive = tlvList.find(0x95, TlvFindMode.STRICT) // throws if duplicated

MIT — see LICENSE for details.