Example 07: CCT Lock and Release

This example covers the full LockRelease CCT flow on Sepolia → Amoy:

1. Deploy token + lock box + LockRelease pool on both chains (Hardhat Ignition).
2. Configure pools to trust each other (example07-step1).
3. Fund destination lock box liquidity (example07-step2).
4. Send a token transfer across the lane (example07-step3).
5. Verify lock/release behavior with helper tasks.

Modules and tasks used:

• Deploy token + lock box + pool: Hardhat Ignition module ignition/modules/LockAndReleaseTokenPool.ts (deploy on each chain with the appropriate parameters file).
• Configure remote lane: Hardhat task example07-step1.
• Fund lock box: Hardhat task example07-step2.
• Send CCIP token transfer: Hardhat task example07-step3.
• Verify: Helper tasks token-admin-registry-get-pool, pool-get-remote-token, pool-get-remote-pools, erc20-balance-of.

Before You Start

Important: Keystore first

Use a local keystore account for task execution:

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

Ensure ignition/paramsEthSepolia.json and ignition/paramsAmoy.json contain the correct routerAddress, armProxy, registryModuleOwnerCustom, and tokenAdminRegistry for each chain.

Deployment Defaults

The LockAndReleaseTokenPool Ignition module deploys:

• Token: CrossChainToken with the same defaults and registerAdminViaGetCCIPAdmin flow as Example 06: TestToken (TEST), 18 decimals, 1_000_000 × 10¹⁸ premint, 100_000_000 × 10¹⁸ max supply.
• Lock box: ERC20LockBox bound to the token.
• Pool: LockReleaseTokenPool with no advanced pool hook (CCT 02).

Step 1: Deploy Token + Lock Box + Pool on Sepolia

npx hardhat ignition deploy ignition/modules/LockAndReleaseTokenPool.ts --network <NETWORK_NAME> --parameters <PARAMETERS_FILE>

--parameters is the path to the chain’s Ignition parameters JSON (e.g. ignition/paramsEthSepolia.json or ignition/paramsAmoy.json); it supplies router, arm proxy, token admin registry, and other addresses to the module.

Save from the deployment output:

• <SEPOLIA_TOKEN_ADDRESS> (CrossChainToken; same defaults as Example 06)
• <SEPOLIA_LOCKBOX_ADDRESS> (ERC20LockBox)
• <SEPOLIA_POOL_ADDRESS> (LockReleaseTokenPool)

Step 2: Deploy Token + Lock Box + Pool on Amoy

npx hardhat ignition deploy ignition/modules/LockAndReleaseTokenPool.ts --network <NETWORK_NAME> --parameters <PARAMETERS_FILE>

Use the parameters file for the chain you are deploying to.

Save from the deployment output:

• <AMOY_TOKEN_ADDRESS>
• <AMOY_LOCKBOX_ADDRESS>
• <AMOY_POOL_ADDRESS>

Step 3: Configure Sepolia Pool With Amoy Remote

npx hardhat example07-step1 --network <NETWORK_NAME> \
  --local-pool <SEPOLIA_POOL_ADDRESS> \
  --remote-chain-selector <AMOY_CHAIN_SELECTOR> \
  --remote-token <AMOY_TOKEN_ADDRESS> \
  --remote-pool <AMOY_POOL_ADDRESS>

Step 4: Configure Amoy Pool With Sepolia Remote

npx hardhat example07-step1 --network <NETWORK_NAME> \
  --local-pool <AMOY_POOL_ADDRESS> \
  --remote-chain-selector <SEPOLIA_CHAIN_SELECTOR> \
  --remote-token <SEPOLIA_TOKEN_ADDRESS> \
  --remote-pool <SEPOLIA_POOL_ADDRESS>

Step 5: Fund Destination Lock Box Liquidity

For Sepolia → Amoy transfers, fund the Amoy lock box first:

npx hardhat example07-step2 --network <NETWORK_NAME> \
  --token <AMOY_TOKEN_ADDRESS> \
  --lock-box <AMOY_LOCKBOX_ADDRESS> \
  --amount <LIQUIDITY_AMOUNT>

Use an amount in wei (e.g. 1000000000000000000000 for 1000 tokens with 18 decimals). If you also want Amoy → Sepolia transfers, fund the Sepolia lock box the same way:

npx hardhat example07-step2 --network <NETWORK_NAME> \
  --token <SEPOLIA_TOKEN_ADDRESS> \
  --lock-box <SEPOLIA_LOCKBOX_ADDRESS> \
  --amount <LIQUIDITY_AMOUNT>

Step 6: Send LockRelease Transfer (ExtraArgsV3 + Default Finality)

npx hardhat example07-step3 --network <NETWORK_NAME> \
  --source-router <SEPOLIA_ROUTER> \
  --destination-chain-selector <DESTINATION_CHAIN_SELECTOR> \
  --receiver <RECEIVER_ON_AMOY> \
  --token-to-send <SEPOLIA_TOKEN_ADDRESS> \
  --amount <AMOUNT> \
  --gas-limit 0 \
  --block-confirmations 0 \
  --fee-token-address <FEE_TOKEN_ADDRESS>

Parameter notes:

• --amount: token amount in wei (e.g. 1000000000000000000 for 1 token with 18 decimals).
• --gas-limit 0: token-only transfer to an EOA receiver.
• This task uses ExtraArgsV3 with blockConfirmations = 0 (default finality).
• --fee-token-address: use 0x0000000000000000000000000000000000000000 for native fee, or the LINK token address on Sepolia for LINK fee.

Step 7: Verify LockRelease Behavior

Verify token→pool registration:

npx hardhat token-admin-registry-get-pool --network <NETWORK_NAME> --registry <TOKEN_ADMIN_REGISTRY> --token <TOKEN_ADDRESS>

Verify remote lane mapping (tasks decode bytes to address):

npx hardhat pool-get-remote-token --network <NETWORK_NAME> --pool <POOL_ADDRESS> --chain-selector <REMOTE_CHAIN_SELECTOR>
npx hardhat pool-get-remote-pools --network <NETWORK_NAME> --pool <POOL_ADDRESS> --chain-selector <REMOTE_CHAIN_SELECTOR>

Verify lock box and receiver balances after transfer finalizes:

npx hardhat erc20-balance-of --network <NETWORK_NAME> --token <TOKEN_ADDRESS> --account <ACCOUNT_ADDRESS>

Monitor message status with the message ID on:

• https://ccip.chain.link