An SPV wallet you can replay, audit and embed.

final mnemonic = await DartSVCryptoService().generateMnemonic();

final wallet = await coordinator.ask(CreateWalletCommand(
  walletId: 'bob',
  name: 'Bob',
  mnemonic: mnemonic, // the wallet's backup: store it safely
));

print(wallet.rootAddress);

final invoice = await coordinator.ask(CreateInvoiceCommand(
  walletId: 'bob',
  amount: BigInt.from(100000), // satoshis
  description: 'Coffee',
));

// Share invoice.invoiceId, invoice.addresses and invoice.amount
// with the payer.

final payment = await coordinator.ask(PayInvoiceCommand(
  walletId: 'alice',
  invoiceId: invoice.invoiceId,
  addresses: [invoice.addresses.first],
  amount: invoice.amount,
));

// payment.beefBytes: the transaction with its ancestors and merkle
// proofs. Not broadcast: your app hands the BEEF to the payee.

try {
  final verdict = await coordinator.ask(ValidateBEEFCommand(
    walletId: 'bob',
    beefHex: beefHex, // the payer's beefBytes, hex-encoded
    invoiceId: invoice.invoiceId,
  ));
  // Checked against Bob's own headers and the invoice, then broadcast.
  print(verdict.networkStatus); // SEEN_ON_NETWORK
} on CoordinatorFailure catch (e) {
  print('Refused: ${e.message}');
}

coordinator.on<InvoicePaidEvent>(walletId: 'bob').listen((e) {
  print('Paid: ${e.amountReceived} sats in ${e.txid}');
});

coordinator.on<TransactionConfirmedEvent>().listen((e) {
  print('${e.txid} confirmed at ${e.blockHeight}');
});

coordinator.on<BalanceUpdatedEvent>().listen((e) {
  print('${e.walletId}: ${e.totalBalance} sats');
});