Bitcoin

Sign messages, send Bitcoin, and work with PSBTs using the Dynamic Flutter SDK.

Overview

The BitcoinModule provides native Bitcoin operations including message signing, PSBT signing, sending Bitcoin, and balance queries. Access it via DynamicSDK.instance.bitcoin.

Prerequisites

• Dynamic SDK initialized (see Quickstart)
• User authenticated (see Authentication)
• Bitcoin wallet available (see Wallet Creation)

Get Balance

Query the Bitcoin balance (in satoshis) for a wallet.

final sdk = DynamicSDK.instance;
final wallet = sdk.wallets.userWallets.first;

final balance = await sdk.bitcoin.getBalance(
  walletId: wallet.id,
);
print('Balance: $balance satoshis');

Sign a Message

Sign a message using the connected Bitcoin wallet. Supports optional protocol and addressType parameters.

final signature = await sdk.bitcoin.signMessage(
  walletId: wallet.id,
  message: 'Hello, Bitcoin!',
);
print('Signature: $signature');

With Protocol and Address Type

// Using BIP-322 simple protocol with payment address
final signature = await sdk.bitcoin.signMessage(
  walletId: wallet.id,
  message: 'Hello, Bitcoin!',
  protocol: 'bip322-simple', // or 'ecdsa'
  addressType: 'payment',     // or 'ordinals'
);

Parameter	Type	Description
walletId	String	The wallet ID to sign with
message	String	The message to sign
protocol	String?	Signing protocol: ecdsa or bip322-simple
addressType	String?	Address type: payment or ordinals

Send Bitcoin

Send Bitcoin to a recipient address. The amount is specified in satoshis.

final txId = await sdk.bitcoin.sendBitcoin(
  walletId: wallet.id,
  recipientAddress: 'bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh',
  amount: '10000', // in satoshis
  feePriority: 'medium', // optional: 'high', 'medium', or 'low'
);
print('Transaction ID: $txId');

Parameter	Type	Description
walletId	String	The wallet ID to send from
recipientAddress	String	The recipient Bitcoin address
amount	String	Amount in satoshis
feePriority	String?	Fee priority: high, medium, or low

Build a PSBT

Build an unsigned Partially Signed Bitcoin Transaction (PSBT) without broadcasting it.

final unsignedPsbt = await sdk.bitcoin.buildPsbt(
  walletId: wallet.id,
  recipientAddress: 'bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh',
  amount: '10000',
  feePriority: 'medium',
);
print('Unsigned PSBT (base64): $unsignedPsbt');

Sign a PSBT

Sign a PSBT using the connected wallet.

final signedPsbt = await sdk.bitcoin.signPsbt(
  walletId: wallet.id,
  request: {
    'unsignedPsbtBase64': unsignedPsbt,
  },
);
print('Signed PSBT: $signedPsbt');

Sign Multiple PSBTs

Batch-sign multiple PSBTs in a single call.

final signedPsbts = await sdk.bitcoin.signPsbts(
  walletId: wallet.id,
  requests: [
    {'unsignedPsbtBase64': psbt1},
    {'unsignedPsbtBase64': psbt2},
  ],
);
print('Signed ${signedPsbts.length} PSBTs');

Send Raw Transaction

Broadcast a raw transaction hex to the Bitcoin network.

final txId = await sdk.bitcoin.sendRawTransaction(
  walletId: wallet.id,
  rawTransaction: '0200000001...', // raw tx hex
);
print('Transaction ID: $txId');

Complete Example

import 'package:dynamic_sdk/dynamic_sdk.dart';

Future<void> bitcoinExample() async {
  final sdk = DynamicSDK.instance;
  final wallet = sdk.wallets.userWallets.first;

  // Check balance
  final balance = await sdk.bitcoin.getBalance(walletId: wallet.id);
  print('Balance: $balance satoshis');

  // Sign a message
  final signature = await sdk.bitcoin.signMessage(
    walletId: wallet.id,
    message: 'Verify wallet ownership',
  );
  print('Signature: $signature');

  // Build and sign a PSBT
  final unsignedPsbt = await sdk.bitcoin.buildPsbt(
    walletId: wallet.id,
    recipientAddress: 'bc1q...',
    amount: '5000',
  );

  final signedPsbt = await sdk.bitcoin.signPsbt(
    walletId: wallet.id,
    request: {'unsignedPsbtBase64': unsignedPsbt},
  );
  print('Signed PSBT: $signedPsbt');

  // Or send directly
  final txId = await sdk.bitcoin.sendBitcoin(
    walletId: wallet.id,
    recipientAddress: 'bc1q...',
    amount: '5000',
    feePriority: 'medium',
  );
  print('Sent! TX: $txId');
}

API Reference

Method	Returns	Description
getBalance	Future<String>	Get wallet balance in satoshis
signMessage	Future<String>	Sign a message
sendBitcoin	Future<String>	Send BTC, returns transaction ID
buildPsbt	Future<String>	Build unsigned PSBT (base64)
signPsbt	Future<String>	Sign a single PSBT
signPsbts	Future<List<String>>	Sign multiple PSBTs
sendRawTransaction	Future<String>	Broadcast raw transaction hex

Next Steps

• TON Operations - TON blockchain operations
• SUI Operations - SUI blockchain operations
• Token Balances - Multi-chain balance queries