bip329_labels 1.0.0

A Dart implementation for Flutter of BIP-329: Wallet Labels Export Format for Bitcoin wallets.

BIP-329 Labels

A Dart implementation of BIP-329: Wallet Labels Export Format for Bitcoin wallet label interoperability.

Installation

flutter pub add bip329_labels

Supported Types

Type	Class	Description
tx	TxLabel	Transaction labels
addr	AddressLabel	Address labels
pubkey	PubkeyLabel	Public key labels
input	InputLabel	Input labels
output	OutputLabel	Output labels (has spendable field)
xpub	XpubLabel	Extended public key labels

Usage

import 'package:bip329_labels/bip329_labels.dart';

void main() {
  // --- Serialization ---
  final txid =
      'f91d0a8a78462bc59398f2c5d7a84fcff491c26ba54c4833478b202796c8aafd';
  final myLabel = 'Account #1 Transaction';
  final origin = "wpkh([d34db33f/84'/0'/1'])";

  // Wrap it up in a TxLabel
  final txLabel = TxLabel(ref: txid, label: myLabel, origin: origin);
  // Pack it into a Map and JSON
  final txMap = txLabel.toMap();
  final txJson = txLabel.toJson();

  // Another label: for an output
  final outputRef = '$txid:1';
  final myOutputLabel = 'my coinjoined output';
  final outputSpendable = false;
  final outputLabel = OutputLabel(
    ref: outputRef,
    label: myOutputLabel,
    spendable: outputSpendable,
  );
  final outputMap = outputLabel.toMap();

  // --- Deserialization ---
  // 🛠 Rebuild from a map
  Bip329Label decodedTxLabel = Bip329Label.fromMap(txMap);

  // ...or from JSON String 📦
  decodedTxLabel = Bip329Label.fromJson(txJson);

  // Quick reality check ✅
  assert(decodedTxLabel is TxLabel);
  assert(decodedTxLabel.ref == txid);
  assert(decodedTxLabel.label == myLabel);
  assert(decodedTxLabel.origin == origin);

  final decodedOutputLabel = Bip329Label.fromMap(outputMap);

  // Output label gets spendable field as specified in BIP-329
  assert(decodedOutputLabel is OutputLabel);
  assert(decodedOutputLabel.ref == outputRef);
  assert(decodedOutputLabel.label == myOutputLabel);
  assert((decodedOutputLabel as OutputLabel).spendable == outputSpendable);

  // --- JSON Lines Format (BIP-329 compliant export/import) ---

  // Create a list of labels for export
  final labels = [txLabel, outputLabel];

  // Export to JSON Lines format (newline-delimited JSON)
  final jsonLinesExport = Bip329Label.toJsonLines(labels);
  print('JSON Lines Export:');
  print(jsonLinesExport);

  // Import back from JSON Lines format
  final importedLabels = Bip329Label.fromJsonLines(jsonLinesExport);

  // Verify round-trip integrity
  assert(importedLabels.length == 2);
  assert(importedLabels[0] is TxLabel);
  assert(importedLabels[1] is OutputLabel);
  assert(importedLabels[0].ref == txid);
  assert((importedLabels[1] as OutputLabel).spendable == outputSpendable);

  print('✅ JSON Lines round-trip successful!');
}