WH x CCTP USDC Bridge Example

Please start by reading the design document.

Wormhole-Scaffolding

This repository was generated from the wormhole-scaffolding template. We recommend using this template as a starting point for cross-chain development on Wormhole.

Prerequisites

Install Foundry tools, which include forge, anvil and cast CLI tools.

Build

Run the following commands to install necessary dependencies and to build the smart contracts:

cd evm
make dependencies
make build

Testing Environment

The testing environments can be found in the following locations:

• Unit Tests
• Integration Tests

First, set the RPC variable in evm/env/testing.env. Then run the tests with the following commands:

# solidity-based unit tests
make unit-test

# local-validator integration tests written in typescript
make integration-test

# unit tests and local-validator integration tests
make test

Contract Deployment

Before deploying the contracts, set the Deployment Variables and RPC for your target networks in the following directories:

• evm/env/testnet
• evm/env/mainnet

Then deploy the contracts by executing the following commands:

# goerli
. env/testnet/eth.env && shell-scripts/deploy_circle_relayer.sh --private-key put_your_private_key_here

# fuji
. env/testnet/avax.env && shell-scripts/deploy_circle_relayer.sh --private-key put_your_private_key_here

Make sure to deploy all contracts (save the contract addresses) before moving onto the Initial Contract Setup section of this README.md.

Hardware wallet deployment

Alternatively, Foundry supports signing with both Ledger and Trezor wallets.

You might need to specify all three of the following arguments:

• --ledger or --trezor to select which hardware wallet should be used to sign.
• --mnemonic-derivation-paths <derivation path of account> to select the path derivation for the account.
• --sender <EVM address> to specify the address of the selected account. Might be necessary to workaround some tx simulation issues.

So for example, you would execute:

# goerli
source env/testnet/eth.env && shell-scripts/deploy_circle_relayer.sh --ledger --mnemonic-derivation-paths your_derivation_path --sender your_address_for_given_path

to deploy on goerli with a ledger wallet.

Contract verification

To verify the contract, you need an API token for the corresponding block explorer. The verification script uses forge verify-contract which verifies the contract on etherscan-like block explorers. Ensure that the verification environment variables RELEASE_EVM_CHAIN_ID and RELEASE_CIRCLE_RELAYER_ADDRESS are set correctly:

• RELEASE_EVM_CHAIN_ID must be set to the EIP-155 chain id.
• RELEASE_CIRCLE_RELAYER_ADDRESS must be set to the address where you deployed the contract.

Then, you only need to run the following:

# Contract verification
source env/testnet_or_mainnet/your_file.env && shell-scripts/verify_contracts.sh your_api_token

Initial Contract Setup

First, copy the evm/cfg/sampleDeployment.json file and update the values based on your deployment configuration:

# start from the evm directory
cd evm
# create the myDeployment.json file
cp cfg/sampleDeployment.json cfg/myDeployment.json
# Set the path of the configuration file in an environment variable that's read by all scripts
export CONFIGURE_CCTP_CONFIG=cfg/myDeployment.json

Next, register the deployed contracts by running the following command for each target network:

# register the contracts
source env/testnet_or_mainnet/your_file.env && PRIVATE_KEY=your_private_key yarn register-contracts

Finally, set up the deployed contracts by running the following command for each target network:

# set up the contracts
source env/testnet_or_mainnet/your_file.env && PRIVATE_KEY=your_private_key yarn configure-contract \
--setSwapRate --setRelayerFee --setMaxSwapAmount

Where the three command-line arguments are defined as:

• --setSwapRate - Sets the native swap rate for the configured tokens.
• --setMaxSwapAmount - Sets the max native swap amount for the configured tokens.
• --setRelayerFee - Sets the outbound relayer fee for the configured tokens and chains.

Signing configuration transactions with a hardware wallet

Only signing txs with a Ledger device is supported at this time. Ensure you've created a deployment configuration file and set CONFIGURE_CCTP_CONFIG to its path.

export CONFIGURE_CCTP_LEDGER=true
export CONFIGURE_CCTP_DERIVATION_PATH=your_derivation_path

# Register the contracts
source env/testnet_or_mainnet/your_file.env && npx ts-node ts/scripts/registerContracts.ts

# Set the swap rate and relayer fee for other chains
source env/testnet_or_mainnet/your_file.env && npx ts-node ts/scripts/configureContract.ts --setSwapRate --setRelayerFee --setMaxSwapAmount

Off-Chain Circle Relayer

Copy the sample .env file in the relayer directory and set the values:

cp .env.sample .env

To run the off-chain relayer process, check that the contract addresses are correct in the relayer/src/circleRelayer/main.ts file, then run the following commands:

cd relayer
npm ci
npm run build
npm run start-circle-relayer

Off-Chain Price Relayer

Copy the sample .env file in the relayer directory and set the values (this .env file is shared with the Off-Chain Circle Relayer process):

cp .env.sample .env

Copy the priceRelayerSample.json file in the relayer/cfg directory and set the values:

cp priceRelayerSample.json priceRelayer.json

To run the off-chain relayer process, check that the contract addresses are correct in the relayer/src/priceRelayer/main.ts file, then run the following commands:

# only run these if you haven't already for the off-chain circle relayer
cd relayer
npm ci

npm run build
npm run start-price-relayer