Client Libraries

Client libraries

Metacces uses Geth which supports common smart contract and dapp development, deployment, and operational use cases, using tools such as Hardhat, web3.js and web3js-quorum. The client supports common JSON-RPC API methods, for example eth, net, web3, debug, and miner.

Prerequisites

web3

The web3.js library is the most widely used for developing applications.

Install web3 in your project

npm install web3

Initialize the web3 client

Initialize your client where:

  • https://oli.accesscan.io is the JSON-RPC HTTP endpoint of your Metacces node.

  • HTTP example

Example connection

const Web3 = require("web3");

const web3 = new Web3("http://oli.accesscan.io");

WS example

Example connection

const Web3 = require("web3");

const web3 = new Web3("http://ws.accesscan.io");

Deploying a contract

To deploy a private contract, you need the contract binary. You can use Solidity to get the contract binary.

myContract.deploy({
   data: '0x12345...',
   arguments: [123, 'My String']
})
.send({
   from: '0x1234567890123456789012345678901234567891',
   gas: 1500000,
   gasPrice: '30000000000000'
}, function(error, transactionHash){ ... })
.on('error', function(error){ ... })
.on('transactionHash', function(transactionHash){ ... })
.on('receipt', function(receipt){
 console.log(receipt.contractAddress) // contains the new contract address
})
.on('confirmation', function(confirmationNumber, receipt){ ... })
.then(function(newContractInstance){
   console.log(newContractInstance.options.address) // instance with the new contract address
});

Alternatively, you can also deploy a contract using eth.sendSignedTransaction

const rawTxOptions = {
 nonce: "0x00",
 from: account.address,
 to: null, //public tx
 value: "0x00",
 data: "0x" + contractBin + contractConstructorInit,
 gasPrice: "0x0", //ETH per unit of gas
 gasLimit: "0x24A22", //max number of gas units the tx is allowed to use
};
console.log("Creating transaction...");
const tx = new Tx(rawTxOptions);
console.log("Signing transaction...");
tx.sign(Buffer.from(account.privateKey.substring(2), "hex"));
console.log("Sending transaction...");
var serializedTx = tx.serialize();
const pTx = await web3.eth.sendSignedTransaction(
 "0x" + serializedTx.toString("hex").toString("hex"),
);
console.log("tx transactionHash: " + pTx.transactionHash);
console.log("tx contractAddress: " + pTx.contractAddress);
return pTx;

web3 methods

For more information about the web3 methods, see the web3 reference documentation.

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