Get started
In this get started tutorial - we will learn how to install, setup and interact with contract api. We will particular learn how we can interact with ERC20 contract.
Installation
You need to install two package
1. Core package
core package contains all the contracts and core implementation
npm i @ethcontracts/core
2. Client package
Client package is a client wrapper for ethereum libraries like ethers.js and web3.js. This allows you to use any of your favourite package.
ethers
npm i @ethcontracts/ethers
web3js
npm i @ethcontracts/web3
Setup
You can use any ethereum library. Currently we support ethers and web3.js.
ethers
import { EthersClient } from "@ethcontracts/ethers";
web3js
import { Web3Client } from "@ethcontracts/web3";
ERC20 balance
Let's see how we can get balance of an erc20 token.
ethers.js
import { ERC20 } from "@ethcontracts/core";
import { EthersClient } from "@ethcontracts/ethers";
import { providers } from "ethers"
// create token with token address
const token = new ERC20("0x8f3cf7ad23cd3cadbd9735aff958023239c6a063");
// create provider
const provider = new providers.JsonRpcProvider('https://polygon-rpc.com');
// initiate token with provider
await token.init(
new EthersClient(provider)
);
// call token balance api
const balance = await token.getBalance("0xd5D3F35Bdd08950CCFE0DeAb638F8B5498297076");
console.log("balance", balance);
web3.js
import { ERC20 } from "@ethcontracts/core";
import { Web3Client } from "@ethcontracts/web3";
import Web3 from "web3";
// create token with token address
const token = new ERC20("0x8f3cf7ad23cd3cadbd9735aff958023239c6a063");
// create provider
const provider = new Web3.providers.HttpProvider('https://polygon-rpc.com');
// initiate token with provider
await token.init(
new Web3Client(provider)
);
// call token balance api
const balance = await token.getBalance("0xd5D3F35Bdd08950CCFE0DeAb638F8B5498297076");
console.log("balance", balance);
transfer
transfer is standard ERC20 method which allows to transfer fund from user account to another user.
It is write transaction which means it changes the state in blockchain transaction. In case of write transaction - we need transaction Hash and transaction receipt.
ethers.js
import { ERC20 } from "@ethcontracts/core";
import { EthersClient } from "@ethcontracts/ethers";
import { providers } from "ethers"
// create token with token address
const token = new ERC20("0x8f3cf7ad23cd3cadbd9735aff958023239c6a063");
// create provider - make sure its wallet provider like metamask, walletconnect etc as its needed to write tx on blockchain
const provider = <wallet provider>;
// initiate token with provider
await token.init(
new EthersClient(provider)
);
// call transfer api
const toAddress = "0xd5D3F35Bdd08950CCFE0DeAb638F8B5498297076";
const [getTransactionHash, getTransactionReceipt] = token.transfer(toAddress,10000);
// get transaction hash
const txHash = await getTransactionHash();
// get tx receipt
const txReceipt = await getTransactionReceipt();
web3.js
import { ERC20 } from "@ethcontracts/core";
import { Web3Client } from "@ethcontracts/web3";
import Web3 from "web3";
// create token with token address
const token = new ERC20("0x8f3cf7ad23cd3cadbd9735aff958023239c6a063");
// create provider - make sure its wallet provider like metamask, walletconnect etc as its needed to write tx on blockchain
const provider = <wallet provider>;
// initiate token with provider
await token.init(
new Web3Client(provider)
);
// call transfer api
const toAddress = "0xd5D3F35Bdd08950CCFE0DeAb638F8B5498297076";
const [getTransactionHash, getTransactionReceipt] = token.transfer(toAddress,10000);
// get transaction hash
const txHash = await getTransactionHash();
// get tx receipt
const txReceipt = await getTransactionReceipt();
You can also configure transaction like passing gas, chain etc. Have a look at this doc - Transaction configuration
👉 While this tutorial covers ERC20, all other contract types like ERC721 and ERC1155 are similar and can be integrated easily.