Overview

This book showcases practical usage of CCIP v2.0 in this Hardhat 3 starter kit.

The goal is not to re-teach CCIP fundamentals. It is to provide runnable example flows you can execute and adapt.

Before You Run Any Example

**Important: Complete the 3 steps below before proceeding.

1. Keystore — Use a local keystore account for task and script execution:

npx hardhat keystore set SEPOLIA_PRIVATE_KEY
npx hardhat keystore set AMOY_PRIVATE_KEY
npx hardhat keystore set SEPOLIA_RPC_URL
npx hardhat keystore set AMOY_RPC_URL

The values from your local keystore are used at runtime (e.g. by hardhat.config.ts for network accounts and RPC URLs).

2. Ignition parameters — Update the JSON parameter files used by Hardhat Ignition for deployment:

• Ethereum Sepolia: ignition/paramsEthSepolia.json
• Polygon Amoy: ignition/paramsAmoy.json

These files supply $global values (such as routerAddress, armProxy, registryModuleOwnerCustom, tokenAdminRegistry, and for some modules thresholdAmountForAdditionalCCVs) to the Ignition modules.

Each module that deploys pools or receivers reads these parameters when you run npx hardhat ignition deploy ... --parameters <file>.

Ensure the addresses in each file match the correct chain (e.g. use the CCIP Directory or your deployment context). If you use the wrong file or outdated addresses, deployments will fail or point to the wrong contracts.

3. Compile — Generate the build artifacts required for deployment and tasks:

npx hardhat compile

Run this before deploying or running examples so that contract ABIs and artifacts are available.

Chain Configuration

Always pull the latest values from the CCIP Directory before running examples.

Examples 01–10 use Sepolia → Amoy. Examples 01, 03, and 04 use faucet-issued CCIP-BnM; Examples 06–10 deploy custom tokens. Verify the lane’s OnRamp 2.0.0 before sending.