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​

• Node.js version 15 or later.

• The web3 library must be installed in your project.

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.

Copy

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

Copy

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.