Blockchain bridge simplified

You can read the full article for this project in the Chainstack blog

This project contains multiple pieces to create a functional (although not production ready) ERC20 blockchain bridge between two EVM compaticle chains.

It uses a wallet as an escrow and leverages the events triggered from the ERC20 tokens to burn and mint tokens in each side of the bridge

Requirements

Node.js / NPM
To use this bridge you'll need access to nodes in different chains. Check out Chainstack website to learn more.

Build & Compile

Smart contracts

Create a Metamask wallet and get some tokens for your target networks. This code was tested with Ropsten and Harmony testnet. You can get Ropsten ETH here and Harmony testnet ONE here.

Run npm i to install all required dependencies.

Rename /solidity/.env.example to /solidity/.env and fill in the details with your wallet address and the RPC endpoints from your Chainstack dashboard.

To deploy your contracts run npm run deploy:ori and npm run deploy:dest.

You'll get the contract address in the console.

You can test the contracts running npm run test.

Front-end

Rename /web/.env.example to /web/.env and fill in the details with your wallet address, RPC endpoints and token addresses from the deployed smart contracts.

To build the front-end, run npm i and npm run build inside the web directory. You can run the front-end locally with npm run dev or deploy the the generated dist folder to any static site hosting.

Back-end

The back-end service is required to actually run the bridge.

Rename /backend/.env.example to /backend/.env and fill in the details with your wallet address, RPC endpoints and token addresses from the deployed smart contracts.

Run npm i inside the backend directory. To start the back-end service run npm start.