Contracts

Contracts for Lido Finance projects. Part of Lido JS SDK

A Contract is an abstraction of code that has been deployed to the blockchain. A Contract may be sent transactions, which will trigger its code to be run with the input of the transaction data. More details in the ethers docs.

It uses TypeChain under the hood to generate TypeScript typings for contacts.

• Install
• Getters
  • getERC20Contract
  • getWSTETHContract
  • getSTETHContract
  • getLDOContract
  • getWithdrawalQueueContract
  • getAggregatorContract
• Cache

Install

yarn add bido-sdk-contracts

Getters

Source

Each getter returns a cached Contract instance with an attached Provider and an ABI. The Provider is required to work with the network and sign transactions and the ABI contains information about methods of the contract on the ethereum side. So, the resulting instance contains all the methods supported by the contract and allows you to call them.

If a contract method requires signing a transaction, then you need a provider with Signer

getERC20Contract

Returns an instance of Contract based on ERC20 standard contract ABI.

import { getERC20Contract } from 'bido-sdk-contracts';
import { JsonRpcProvider } from '@ethersproject/providers';

const provider = new JsonRpcProvider('http://localhost:8545');
const contract = getERC20Contract(
  '0xae7ab96520de3a18e5e111b5eaab095312d7fe84',
  provider,
);

const symbol = await contract.symbol();
const decimals = await contract.decimals();

getWSTETHContract

Returns an instance of Contract based on wstETH contract ABI. Available contract methods and detailed documentation can be found here: https://docs.lido.fi/contracts/wsteth

getSTETHContract

Returns an instance of Contract based on stETH contract ABI. Available contract methods and detailed documentation can be found here: https://docs.lido.fi/contracts/lido

getLDOContract

Returns an instance of Contract based on LDO token ABI. LDO Token docs can be found here: https://docs.lido.fi/lido-dao/#ldo-token

getWithdrawalQueueContract

Returns an instance of Contract based on WithdrawalQueue contract ABI. Contract docs here: https://docs.lido.fi/contracts/withdrawal-queue-erc721

getAggregatorContract

Returns an instance of Contract based on ChainLink USD/ETH price oracle ABI. EACAggregatorProxy https://etherscan.io/address/0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419

Cache

To get another contract instance, getters have a third optional parameter cacheSeed.

Calls without cacheSeed or with the same cacheSeed return the same contracts:

const contractFirst = getERC20Contract('0x0...', provider, 1);
const contractSecond = getERC20Contract('0x0...', provider, 1);

contractFirst === contractSecond; // true

Calls with different cacheSeed return different contracts:

const contractFirst = getERC20Contract('0x0...', provider, 1);
const contractSecond = getERC20Contract('0x0...', provider, 2);

contractFirst !== contractSecond; // true

Of course, if the cacheSeed is the same, but address or provider are different the result contracts will also be different:

const contractFirst = getERC20Contract('0x1...', provider, 1);
const contractSecond = getERC20Contract('0x0...', provider, 1);

contractFirst !== contractSecond; // true, because the addresses are different