Contracts

Contracts for Knine projects. Part of Knine 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
  • getSTETHContract // eth shib
  • getWithdrawalQueueContract // unstBone
  • getAggregatorContract //
  • // instant pool
  • // x2 bridge
• Cache

Install

yarn add @knine-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 '@knine-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();

getSTETHContract

Returns an instance of Contract based on stETH contract ABI.

getWithdrawalQueueContract

Returns an instance of Contract based on WithdrawalQueue contract ABI.

getAggregatorContract

Returns an instance of Contract based on ChainLink USD/ETH price oracle ABI.

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