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 enabled in the Dynamic dashboard

Get a Bitcoin Wallet

There are two paths to a Bitcoin wallet: filter the user’s existing wallets, or create a new one explicitly.

Filter existing wallets

If Bitcoin is enabled and the user has a Bitcoin wallet (created automatically at signup), find it via userWallets:

final sdk = DynamicSDK.instance;

final btcWallet = sdk.wallets.userWallets.firstWhere(
  (w) => w.chain == 'BTC',
  orElse: () => throw StateError('No Bitcoin wallet found'),
);

print('Bitcoin address: ${btcWallet.address}');

Create a new Bitcoin wallet

Call createWallet with EmbeddedWalletChain.btc:

final wallet = await sdk.wallets.embedded.createWallet(
  chain: EmbeddedWalletChain.btc,
);

print('Created: ${wallet.address}');

Bitcoin wallets are derived as Native SegWit (bc1q…) by default. Mainnet is the only network supported today.

What is a satoshi?

A satoshi is the smallest unit of Bitcoin — 1 BTC = 100,000,000 satoshis. All amount fields in the Bitcoin module (sendBitcoin, buildPsbt, getBalance) are expressed in satoshis, not BTC.

What is a PSBT?

A Partially Signed Bitcoin Transaction (PSBT) is a standard for transactions that have not yet been fully signed. It allows different participants with different keys to sign a transaction without sharing private keys, enabling safer multi-step or multi-sig flows.

Get Balance

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

final sdk = DynamicSDK.instance;
final wallet = sdk.wallets.userWallets.firstWhere(
  (w) => w.chain == 'BTC',
);

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

getBalance returns a Future<String> — satoshis as a string to preserve precision.

Operations

Detailed guides for each Bitcoin operation:

• Sign a Message — sign arbitrary messages (ECDSA or BIP-322)
• Send Bitcoin — one-call transfer
• Build a PSBT — construct an unsigned PSBT
• Sign a PSBT — sign one or many PSBTs
• Send Raw Transaction — broadcast a pre-signed transaction

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