Mobile Libraries

Web3Dart

Library written in dart that enables interaction with EVM compatible blockchains.

Available on:

Works on All SKALE Chains

Some of the features of the library are:

• Send signed transactions
• Generate new wallets
• Call functions on smart contracts and listen for contract events
• Code generation based on smart contract ABI for easier interaction

Implementation Example

1. Package Install

   dart pub add web3dart

2. Contract Call

   // ignore_for_file: public_member_api_docs
   import 'dart:io';
   
   import 'package:http/http.dart';
   import 'package:web3dart/web3dart.dart';
   import 'package:path/path.dart' show join, dirname;
   import 'package:web_socket_channel/io.dart';
   import 'chains.dart';
   
   //Private Key
   const String privateKey ='your pk';
   
   //Select which chain you want to use
   Chain? selected_SKALE_chain = chains[ChainKey.nebula];
   
   // SKALE Chain RPC
   String rpcUrl = selected_SKALE_chain?.chainInfo?.testnet.rpcUrl ?? "no url";
   // selected SKALE Chain ID
   int chainId = selected_SKALE_chain?.chainInfo?.testnet.chainId ?? 0;
   
   // ABI of ERC_721 example contract
   final File abiFile = File(join(dirname(Platform.script.path), 'abi.json'));
   
   
   Future<void> main() async {
   
     // start a client we can use to send transactions
     final client = Web3Client(rpcUrl, Client());
   
     final EthereumAddress mint_to_address = EthereumAddress.fromHex('address to mint to');
   
     String address = selected_SKALE_chain?.chainInfo?.testnet.contracts[0].address ?? "no address";
   
     final EthereumAddress contract_address = EthereumAddress.fromHex(address);
   
     //Credentials to sign tx
     final credentials = EthPrivateKey.fromHex(privateKey);
   
     //ABI file as string
     final abiCode = await abiFile.readAsString();
   
     final contract = DeployedContract(ContractAbi.fromJson(abiCode, 'MyToken'), contract_address);
     //Selected contract function to call
     final mintFunction = contract.function('mintTest');
   
     // Mint function call
     //Note: The chainId needs to be passes otherwise it will throw the error: -32004 Invalid transaction signature.
     final tx = await client.sendTransaction(
       credentials,
       Transaction.callContract(
         contract: contract,
         function: mintFunction,
         parameters: [mint_to_address],
       ),
       chainId: chainId
     );
   
     // Transaction Receipt
     final receipt = await client.addedBlocks().asyncMap((_) => client.getTransactionReceipt(tx)).firstWhere((receipt) => receipt != null);
     print(receipt);
   
     await client.dispose();
   }

3. Run

   dart web/main.dart

Additional Web3Dart Documentation

Click here for the official documentation.

JSON-RPC Calls

When some platforms or frameworks don't have any quality web3 library or SDK, there's always the possibility to make the blockchain calls directly to the JSON-RPC methods supported by the chain.

Available on:

Works on All SKALE Chains

Some of the JSON-RPC methods supported by SKALE chains are:

• eth_getBalance
• eth_blockNumber
• eth_getTransactionCount
• eth_sendTransaction
• eth_call

Implementation Example

Get Balance

import axios from 'axios';

const rpcEndpoint = 'YOUR SKALE RPC ENDPOINT';
const senderAddress = '0x...';


const requestData_balance = {
    jsonrpc: '2.0',
    method: 'eth_getBalance',
    params: [senderAddress, 'latest'],
    id: 1,
  };


async function JSON_RPC_CALL() {
    try {
        const response = await axios.post(rpcEndpoint,requestData_balance);
        return console.log(response.data);
      } catch (error) {
        console.error(error);
        return [[],[]];
      }
}

JSON_RPC_CALL();

Additional JSON-RPC Calls Documentation

Click here for the official documentation.