README.md

contract-qrc20

This example shows how to multi-chain deploy and interact with a QRC20 token. It is comprised of 2 example scripts:

• 1_deploy_and_link_qrc20.js - multi-chain deploy a QRC20 token and link all sister contracts
• 2_interact_qrc20.js - send tokens from one address to another (on any shard) using a QRC20 contract

Dependencies

• Node.js - JavaScript runtime
• quais - Quai JavaScript SDK
• quais-polling - polling provider for Quai
• dotenv - environment variable loader

Usage

To install dependencies, navigate to this directory quais-by-example/contract-qrc20 and run:

npm install

Create a local .env file from the template .env.example and fill in the values:

cp .env.example .env

Use nodejs to run any of the scripts in this example. For example:

node 1_deploy_and_link_qrc20.js

Example Breakdown

1_deploy_and_link_qrc20.js

This script deploys an inidividual QRC20 token contract to more than one chain within Quai Network and links them together. It is comprised of two parts:

• deployQRC20 - deploys a QRC20 token contract to a single chain
• linkQRC20 - links a QRC20 token contract to a sister contract on a different chain

These functions will be looped over for each chain you specify in the deployConfig object. You'll need to edit the deployConfig object to match your desired deployment configuration.

You'll also need to edit the constructorArgs object to match your desired QRC20 token configuration. Note: the totalSupply argument will be replicated for each chain's deployment. If you want to have different total supplies for each chain, you'll need to change the script configuration.

const constructorArgs = {
	name: 'Quai Token', // name
	symbol: 'QUAI', // symbol
	totalSupply: 1000000000000, // local total supply of the token on each chain you deploy to
}

Once you've done the above, you can run the script with:

node 1_deploy_and_link_qrc20.js

Once the script completes, you'll have a fully linked network of QRC20 contracts across multiple chains. This will allow you to send tokens from one chain to another via the transfer function in the QRC20 contract.

2_interact_qrc20.js

This script builds a transaction to send tokens from a specified address to another using your deployed and linked contracts from above. If you provide a toAddress on a different shard than the sender and you have not deployed a sister contract on that shard, the transaction will fail.

To configure the send, you'll need to provide the following:

• rpcURL - the RPC URL of the chain you want to send the transaction on
• privKey - the private key of the address you want to send the transaction from
• contractAddress - the address of the QRC20 token contract you want to interact with
• toAddress - the address you want to send tokens to

Once you've configured the variables above in the script, you can run it with:

node 2_interact_qrc20.js