pilagod/l1-bridge-poc

L1 bridge PoC

L1 Bridge PoC

Cross L1 bridge PoC

Setup

Environment Variables

Check .env.example for required environment variables and fill them in your own .env.

Wallet:

• WALLET_PRIVATE_KEY: Wallet private key shared for L1

RPC:

• KOVAN_RPC_URL: Kovan rpc url
• RINKEBY_RPC_URL: Rinkeby rpc url

This project is aim for EVM-compatible chains, currently it supports Kovan and Rinkeby. Chains can be expanded easily, please refer to Expand Chain for more details.

Prepare ETH

You need to get ETH to the wallet set in environment for chains you want to operate.

• Kovan faucet: https://github.com/kovan-testnet/faucet
• Rinkeby faucet: https://faucet.rinkeby.io

Installation

yarn install
yarn build
yarn migration:up

Bridge

Start a L1 bridge with following command:

yarn execute bridge/L1

This command will spin up a watcher and a worker:

• Watcher: Wait for withdraws and record them.
• Worker: Confirm and finalize withdraws and deposit them to destination on other chain.

After bridge starts, you can mint TKN, which is our test token, on specific chain by below command:

yarn execute scripts/mint.ts --help

Options:
    --version      Show version number                                   [boolean]
    -c, --chain    Chain name or id                            [string] [required]
    -h, --help     Show help                                             [boolean]

# mint 100 TKN for Rinkeby
yarn execute scripts/mint.ts -c 4

# mint 100 TKN for Kovan
yarn execute scripts/mint.ts -c 42

With enough TKN, you can withdraw them cross chains with below command:

yarn execute scripts/withdraw.ts --help

Options:
    --version      Show version number                                   [boolean]
    -f, --from     From chain name or id                       [string] [required]
    -t, --to       To chain name or id                         [string] [required]
    -h, --help     Show help                                             [boolean]

# withdraw 10 TKN from Rinkeby to Kovan
yarn execute scripts/withdraw.ts -f 4 -t 42

Go and check the terminal running bridge or logger/logger.log to see what is happening.

Expand Chain

To support new EVM-compatible chain, here are the steps:

1. Add {CHAIN}_RPC_URL to environment variable.
2. Add new chain to network/chain.ts.
3. Add new chain network to hardhat.config.ts.
4. Deploy TKN to that chain via hardhat --network {chain} deploy --no-compile.
5. Register new deployed TKN contract to network/contract.ts.

That's it. You can withdraw TKN to this new chain.