How to deploy contract with ether.js

Question

I am trying to figure out the best way to deploy a contract using ethers.js

with web3 I can just do:

     const contractInstance = new this.web3.eth.Contract(contractObject.abi)
        var deployTx
        debug(contractInstance)
        if (params === undefined || params.length === 0) {
          deployTx = contractInstance.deploy({
            data: contractObject.bytecode
          })
        } else {
          deployTx = contractInstance.deploy({
            data: contractObject.bytecode,
            arguments: params
          })
        }
        const data = await deployTx.encodeABI()

However with Web 3 I also seem to need an address? and to get that address I have to first manually deploy it. Some clarity around the topic would really help.

I've tried to find resources specifying this but they are not what what im looking for I think?

Thanks in advance

could you please elaborate or point me in the right direction?
What I have gathered is this: The documentation doesnt seem to go in too deep into the deployment itself? — Lucas Rodriguez Benitez, Jun 29 '20 at 19:47

score 15 · Accepted Answer · answered Jun 29 '20 at 21:15

15

You can deploy a contract using Ethers.js' ContractFactory.

import { ContractFactory } from 'ethers';
const factory = new ContractFactory(contractAbi, contractByteCode);
// If your contract requires constructor args, you can specify them here
const contract = await factory.deploy(deployArgs);
console.log(contract.address);
console.log(contract.deployTransaction);

More information can be found in the documentation, found here: https://docs.ethers.io/v5/api/contract/contract-factory/

answered Jun 29 '20 at 21:15

Morten

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this returns an error Cannot read property 'sendTransaction' of null – Lucas Rodriguez Benitez Jun 30 '20 at 03:23
@LucasRodriguezBenitez Make sure that you have provided your mnemonic or array of private key to the Ethereum development framework you're using. For example, these are the docs for Hardhat. – Paul Razvan Berg Jan 11 '21 at 09:31
Would like to know how to set the provider as well; i came here with no prior usage of ethers. – Stevers Dec 01 '21 at 03:54

score 6 · Answer 2 · edited Sep 21 '22 at 12:42

To further elaborate Marten's answer, I will try to give a complete script. Assuming you have installed metamask, and know the seed phrase, here are steps to deploy contract using 'ethers' and 'fs':

compile the contract to .bin and .abi files
load 'ethers' and 'fs'
create a 'signer' object using 'provider', 'Wallet', and 'connect' methods from 'ethers'
create a contract instance from 'ContractFactory' method
use deploy method as promise

Here I have used 'getblock' as web3 provider for example (see https://getblock.io/docs/get-started/auth-with-api-key/). Other alternatives are 'quicknode', 'alchemy' and 'infura'.

nodejs script for contract deployment goes here:

//load 'ethers' and 'fs'
const ethers = require('ethers');
const fs = require('fs');
//Read bin and abi file to object; names of the solcjs-generated files renamed
bytecode = fs.readFileSync('storage.bin').toString();
abi = JSON.parse(fs.readFileSync('storage.abi').toString());
//to create 'signer' object;here 'account'
const mnemonic = "<see-phrase>" // seed phrase for your Metamask account
const provider = new ethers.providers.WebSocketProvider("wss://bsc.getblock.io/testnet/?api_key=<your-api-key>");
const wallet = ethers.Wallet.fromMnemonic(mnemonic);
const account = wallet.connect(provider);
const myContract = new ethers.ContractFactory(abi, bytecode, account);
//Ussing async-await for deploy method
async function main() {
  // If your contract requires constructor args, you can specify them here
  const contract = await myContract.deploy();
console.log(contract.address);
  console.log(contract.deployTransaction);
}
main();

In the above code 'account' is the of the ethers docs https://docs.ethers.io/v5/api/contract/contract-factory/#ContractFactory--creating

ethers.ContractFactory( interface , bytecode [ , signer ] )

Please ask if still having problem.

Is there a method without the seed phrase because i want to launch contracts for people using their wallet without touching their seed or private keys. — CodeGuru, Sep 01 '22 at 06:51
No. The seed created by Metamask is just a proxy for the private keys. Consider it as a mapping. Essentially, all interactions with blockchain is an RPC call, but gas consuming interactions, such as contract deployment, require private key of the user address. — Rahuldev, Sep 02 '22 at 07:41
Yes, of course there is. Just use a MetaMask signer. You can initialize the provider with const provider = new ethers.providers.Web3Provider(window.ethereum), and then you can pass the provider.getSigner() into the contract factory. But this needs to happen on the client side of course. — CherryDT, Oct 31 '22 at 20:49
the problem is that we cant use fs (to ready the contract) in client side — Adri HM, Apr 12 '23 at 20:35

How to deploy contract with ether.js

2 Answers2