The Dynamic SDK Web3Dart is a dart package that provides a few methods for interacting with the Ethereum blockchain. It connects to an Ethereum through web3dart node to send transactions, interact with smart contracts and much more!

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Installation

Simply run the following in your terminal:

flutter pub add dynamic_sdk_web3dart

This will add a line like this to your package’s pubspec.yaml (and run an implicit flutter pub get):

dependencies:
  dynamic_sdk_web3dart: ^0.0.1-alpha.2

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Main Features

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1. Sign Message

Future<String> signMessage({
  required BaseWallet wallet,
  required String message,
}) async {
  
  final requestChannel = RequestChannel(
    DynamicSDK.instance.messageTransport,
  );
  
  final signedMessage = await DynamicCredential.fromWallet(
    requestChannel: requestChannel,
    wallet: wallet,
  ).signMessage(
    payload: Uint8List.fromList(
      message.codeUnits,
    ),
  );

  return signedMessage;
}

​
2. Send Transaction

Future<String> web3dartSendTransaction({
  required BaseWallet wallet,
  required String recipientAddress,
  required String amount,
}) async {
  final recipient = EthereumAddress.fromHex(
    recipientAddress,
  );

  final network = await DynamicSDK.instance.wallets.getNetwork(
    wallet: wallet,
  );

  final service = DynamicRpcService(
    requestChannel: RequestChannel(
      DynamicSDK.instance.messageTransport,
    ),
    chainId: network.intValue() ?? 0,
  );

  final client = Web3Client.custom(service);

  final gasPrice = await client.getGasPrice();

  final maxFeePerGas =
      gasPrice.getValueInUnitBI(EtherUnit.wei) * BigInt.from(2);

  final maxPriorityFeePerGas = gasPrice.getValueInUnitBI(EtherUnit.wei);

  final amountInWei =
      (double.parse(amount) * BigInt.from(10).pow(18).toDouble()).toInt();

  final transaction = Transaction(
    to: recipient,
    maxGas: 21000,
    gasPrice: gasPrice,
    maxFeePerGas: EtherAmount.inWei(
      maxFeePerGas,
    ),
    maxPriorityFeePerGas: EtherAmount.inWei(
      maxPriorityFeePerGas,
    ),
    value: EtherAmount.inWei(
      BigInt.from(amountInWei),
    ),
  );

  final requestChannel = RequestChannel(
    DynamicSDK.instance.messageTransport,
  );

  final dynamicCredential = DynamicCredential.fromWallet(
    requestChannel: requestChannel,
    wallet: wallet,
  );

  final signedTransaction = await dynamicCredential.sendTransaction(
    transaction,
  );

  return signedTransaction;
}

​
3. Sign Contract

Future<String> writeContract({
  required BaseWallet wallet,
  required String message,
}) async {
  final requestChannel = RequestChannel(
    DynamicSDK.instance.messageTransport,
  );

  final dynamicCredential = DynamicCredential.fromWallet(
    requestChannel: requestChannel,
    wallet: wallet,
  );

  final network = await DynamicSDK.instance.wallets.getNetwork(
    wallet: wallet,
  );

  final service = DynamicRpcService(
    requestChannel: RequestChannel(
      DynamicSDK.instance.messageTransport,
    ),
    chainId: network.intValue() ?? 0,
  );

  final client = Web3Client.custom(service);

  final gasPrice = await client.getGasPrice();

  final maxFeePerGas =
      gasPrice.getValueInUnitBI(EtherUnit.wei) * BigInt.from(2);

  final maxPriorityFeePerGas =
      gasPrice.getValueInUnitBI(EtherUnit.wei) * BigInt.from(2);

  final contract = DeployedContract(
    ContractAbi.fromJson(TestContract.contractAbi, ''),
    TestContract.deployedAddress,
  );

  final updateFunction = contract.function('update');

  final transaction = Transaction.callContract(
    contract: contract,
    maxFeePerGas: EtherAmount.inWei(
      maxFeePerGas,
    ),
    maxPriorityFeePerGas: EtherAmount.inWei(
      maxPriorityFeePerGas,
    ),
    function: updateFunction,
    parameters: [
      message,
    ],
  );

  final signedContract = await dynamicCredential.sendTransaction(
    transaction,
  );

  return signedContract;
}

You can read more about our client package here.

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