Enable your tokens in CCIP (Lock & Mint): Register from an EOA using Hardhat

Guide Versions

This guide is available in multiple versions. Choose the one that matches your needs.

This tutorial will guide you through the process of enabling your own tokens in CCIP using Hardhat. You will learn how to deploy tokens, set up a Lock & Release token pool on the source blockchain, and a Burn & Mint token pool on the destination blockchain. After that, you will register them in CCIP and configure them without needing manual intervention. Finally, you will test the Lock & Mint token handling mechanism, where tokens are locked on the source blockchain and an equivalent amount is minted on the destination blockchain.

We will cover the following key steps:

  1. Deploying Tokens: You will deploy your BurnMintERC20 tokens on the Avalanche Fuji and Arbitrum Sepolia testnets.

  2. Deploying Token Pools: Once your tokens are deployed, you will deploy LockReleaseTokenPool on Avalanche Fuji and BurnMintTokenPool token pools on Arbitrum Sepolia. These pools are essential for testing the Lock & Mint token transfer mechanism: Locking the tokens on the source blockchain and then minting an equivalent amount of tokens on the destination blockchain. Each token will be linked to a pool, which will manage token transfers and ensure proper handling of assets across chains.

  3. Claiming Mint and Burn Roles: You will claim the mint and burn roles for the destination token pool, allowing it to mint and burn tokens during cross-chain transfers.

  4. Claiming and Accepting the Admin Role: This is a two-step process:

    1. You will call the RegistryModuleOwnerCustom contract's registerAdminViaOwner function to register your EOA as the token admin. This role is required to enable your token in CCIP.

    2. Once claimed, you will call the TokenAdminRegistry contract's acceptAdminRole function to complete the registration process.

  5. Linking Tokens to Pools: You will call the TokenAdminRegistry contract's setPool function to associate each token with its respective token pool.

  6. Configuring Token Pools: You will call the applyChainUpdates function on your token pools to configure each pool by setting cross-chain transfer parameters, such as token pool rate limits and enabled destination chains.

  7. Minting Tokens: You will call the mint function to mint tokens on Avalanche Fuji for your EOA. These tokens will later be used to test cross-chain transfers to Arbitrum Sepolia.

  8. Transferring Tokens: Finally, you will transfer tokens from Avalanche Fuji to Arbitrum Sepolia using CCIP. You will have the option to pay CCIP fees in either LINK tokens or native gas tokens.

By the end of this tutorial, you will have successfully deployed, registered, configured, and enabled your tokens and token pools for use in CCIP.

Before You Begin

  1. Make sure you have Node.js v22.10.0 or above installed. If not, install Node.js v22.10.0:

    Download Node.js v22.10.0 if you don't have it installed. Optionally, you can use the nvm package to switch between Node.js versions:

    nvm use 22

    Verify that the correct version of Node.js is installed:

    node -v

    Example output:

    $ node -v
v22.15.0

  2. Clone the repository and navigate to the project directory:

    git clone https://github.com/smartcontractkit/smart-contract-examples.git
cd smart-contract-examples/ccip/cct/hardhat

  3. Install dependencies for the project:

    npm install

  4. Compile the project:

    npm run compile

  5. Encrypt your environment variables for higher security:
    The project uses @chainlink/env-enc to encrypt your environment variables at rest. Follow the steps below to configure your environment securely:

    1. Set an encryption password for your environment variables:

      npx env-enc set-pw

    2. Set up a .env.enc file with the necessary variables for Avalanche Fuji and Ethereum Sepolia. Use the following command to add the variables:

      npx env-enc set

      Variables to configure:

      • AVALANCHE_FUJI_RPC_URL: A URL for the Avalanche Fuji testnet. You can get a personal endpoint from services like Alchemy or Infura.
      • ETHEREUM_SEPOLIA_RPC_URL: A URL for the Ethereum Sepolia testnet. You can sign up for a personal endpoint from Alchemy or Infura.
      • PRIVATE_KEY: The private key for your testnet wallet. If you use MetaMask, you can follow this guide to export your private key. Note: This key is required for signing transactions like token transfers.
      • ETHERSCAN_API_KEY: An API key from Etherscan to verify your contracts. You can obtain one from Etherscan.

  6. Fund your EOA with LINK and native gas tokens:
    Make sure your EOA has enough LINK and native gas tokens on Avalanche Fuji and Ethereum Sepolia to cover transaction fees. You can use the Chainlink faucets to get testnet tokens.

Tutorial

Deploy Tokens

In this step, you will use the deployToken task to deploy tokens on two testnets, Avalanche Fuji and Ethereum Sepolia. Below is an explanation of the parameters used during deployment:

ParameterDescriptionDefaultRequired
nameThe name of the token. This is the full name by which the token will be identified.N/AYes
symbolThe symbol of the token. This is the shorthand (usually 3-5 letters) representing the token.N/AYes
decimalsThe number of decimals the token will use. For instance, 18 decimals means 1 token is represented as 1e18 smallest units.18No
maxsupplyThe maximum supply of tokens. Use 0 for unlimited supply.0No
verifycontractFlag to verify the contract on Etherscan or a similar blockchain explorer. Pass this flag to enable verification, omit to skip.falseNo
networkThe blockchain on which the token will be deployed. Examples include avalancheFuji, ethereumSepolia, baseSepolia, and arbitrumSepolia.N/AYes

Deploy tokens, use the following commands, substituting the token name and symbol as needed:

  1. Deploy the token on Avalanche Fuji:

    npx hardhat deployToken --name "BnM sak" --symbol BnMsak --decimals 18 --maxsupply 0 --premint 100000000000000000000 --verifycontract --network avalancheFuji

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T09:49:50.588Z info: 🚀 Deploying BurnMintERC20 to avalancheFuji...
2025-10-22T09:49:50.589Z info:    name: BnM sak, symbol: BnMsak
2025-10-22T09:49:55.714Z info: ⏳ Deployment tx: 0x4b764e27bc0e47f8fcec6b59e22a0e56aede0a08a03f7f40737b53fddc4e90d1
2025-10-22T09:49:55.715Z info:    Waiting for 2 confirmation(s)...
2025-10-22T09:50:00.519Z info: ✅ Token deployed at: 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5
2025-10-22T09:50:01.179Z info: Granting mint and burn roles to 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA...
2025-10-22T09:50:02.422Z info:    Waiting for 2 confirmation(s)...
2025-10-22T09:50:11.467Z info: ✅ Mint/Burn roles granted.
2025-10-22T09:50:11.468Z info: Verifying contract...

The contract at 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 has already been verified on SnowTrace.

If you need to verify a partially verified contract, please use the --force flag.

Explorer: https://testnet.snowtrace.io/address/0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5#code
2025-10-22T09:50:14.859Z info: ✅ Token contract verified successfully

  2. Deploy the token on Ethereum Sepolia:

    npx hardhat deployToken --name "BnM sak" --symbol BnMsak --decimals 18 --maxsupply 0 --premint 100000000000000000000 --verifycontract --network ethereumSepolia

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T09:51:04.733Z info: 🚀 Deploying BurnMintERC20 to ethereumSepolia...
2025-10-22T09:51:04.734Z info:    name: BnM sak, symbol: BnMsak
2025-10-22T09:51:17.638Z info: ⏳ Deployment tx: 0x187bac7cfc7ea95c41374baedbf98b6bc1bff121f5f1a49d17457458417eee66
2025-10-22T09:51:17.638Z info:    Waiting for 3 confirmation(s)...
2025-10-22T09:52:21.497Z info: ✅ Token deployed at: 0xb613B55897F07eAF430bF9a509498e55487305Ea
2025-10-22T09:52:23.669Z info: Granting mint and burn roles to 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA...
2025-10-22T09:52:26.363Z info:    Waiting for 3 confirmation(s)...
2025-10-22T09:53:03.003Z info: ✅ Mint/Burn roles granted.
2025-10-22T09:53:03.003Z info: Verifying contract...

The contract at 0xb613B55897F07eAF430bF9a509498e55487305Ea has already been verified on Etherscan.

If you need to verify a partially verified contract, please use the --force flag.

Explorer: https://sepolia.etherscan.io/address/0xb613B55897F07eAF430bF9a509498e55487305Ea#code
2025-10-22T09:53:07.664Z info: ✅ Token contract verified successfully

Deploy Token Pools

In this step, you will use the deployTokenPool task to deploy token pools for the tokens on both testnets, Avalanche Fuji and Ethereum Sepolia. Below is an explanation of the parameters used during deployment:

ParameterDescriptionDefaultRequired
tokenaddressThe address of the token for which the pool is being created.N/AYes
pooltypeThe type of pool to deploy. For this tutorial, we use "lockRelease" on Avalanche Fuji and "burnMint" on Ethereum Sepolia."burnMint"No
localtokendecimalsThe number of decimals for the token on this chain.18No
verifycontractFlag to verify the contract on Etherscan or a similar blockchain explorer. Pass this flag to enable verification, omit to skip.falseNo
networkThe blockchain on which the token pool will be deployed. Examples include avalancheFuji, ethereumSepolia, baseSepolia, and arbitrumSepolia.N/AYes

Deploy token pools using the following commands, replacing the token address with the one you deployed in the previous step:

  1. Deploy the lock and release token pool on Avalanche Fuji:

    npx hardhat deployTokenPool \
  --tokenaddress 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 \
  --pooltype lockRelease \
  --localtokendecimals 18 \
  --verifycontract \
  --network avalancheFuji

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:08:45.487Z info: 🚀 Deploying lockRelease pool on avalancheFuji
2025-10-22T13:08:45.488Z info:    Token: 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5
2025-10-22T13:08:45.488Z info:    Decimals: 18
2025-10-22T13:08:45.488Z info:    Allowlist: None
2025-10-22T13:08:51.221Z info: ⏳ Deployment tx: 0xb027c026b72626c7d83e8fb2902c982685376a62d1c90655fee6855df3cdf23a
2025-10-22T13:08:51.221Z info:    Waiting for 2 confirmation(s)...
2025-10-22T13:09:00.473Z info: ✅ Token pool deployed at: 0x10db2Fd0A5E3e9F68c72ae99CC266f383c1814a2
2025-10-22T13:09:00.474Z info: Verifying contract...

📤 Submitted source code for verification on SnowTrace:

  @chainlink/contracts-ccip/contracts/pools/LockReleaseTokenPool.sol:LockReleaseTokenPool
  Address: 0x10db2Fd0A5E3e9F68c72ae99CC266f383c1814a2

⏳ Waiting for verification result...


✅ Contract verified successfully on SnowTrace!

  @chainlink/contracts-ccip/contracts/pools/LockReleaseTokenPool.sol:LockReleaseTokenPool
  Explorer: https://testnet.snowtrace.io/address/0x10db2Fd0A5E3e9F68c72ae99CC266f383c1814a2#code
2025-10-22T13:09:15.173Z info: ✅ Token pool contract verified successfully

  2. Deploy the burn and mint token pool on Ethereum Sepolia:

    npx hardhat deployTokenPool \
  --tokenaddress 0xb613B55897F07eAF430bF9a509498e55487305Ea \
  --pooltype burnMint \
  --localtokendecimals 18 \
  --verifycontract \
  --network ethereumSepolia

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:10:30.678Z info: 🚀 Deploying burnMint pool on ethereumSepolia
2025-10-22T13:10:30.678Z info:    Token: 0xb613B55897F07eAF430bF9a509498e55487305Ea
2025-10-22T13:10:30.678Z info:    Decimals: 18
2025-10-22T13:10:30.678Z info:    Allowlist: None
2025-10-22T13:10:39.505Z info: ⏳ Deployment tx: 0xb1eed241f64f0a5427559b791f576b834885311b916b48c5ee86f711541d54b0
2025-10-22T13:10:39.506Z info:    Waiting for 3 confirmation(s)...
2025-10-22T13:11:16.425Z info: ✅ Token pool deployed at: 0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A
2025-10-22T13:11:16.425Z info: Granting mint and burn roles to 0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A on token 0xb613B55897F07eAF430bF9a509498e55487305Ea
2025-10-22T13:11:19.296Z info:    Waiting for 3 confirmation(s)...
2025-10-22T13:11:51.815Z info: ✅ Mint/Burn roles granted
2025-10-22T13:11:51.815Z info: Verifying contract...

The contract at 0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A has already been verified on Etherscan.

If you need to verify a partially verified contract, please use the --force flag.

Explorer: https://sepolia.etherscan.io/address/0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A#code
2025-10-22T13:11:55.646Z info: ✅ Token pool contract verified successfully

Claim Admin

In this step, you will use the claimAdmin task to register your EOA as the administrator for the deployed tokens on both testnets, Avalanche Fuji and Ethereum Sepolia. This process involves calling the RegistryModuleOwnerCustom contract, which will fetch the CCIP admin of the token and set it up as the admin in the registry.

Below is an explanation of the parameters used during the admin claim process:

ParameterDescriptionDefaultRequired
tokenaddressThe address of the token for which the admin role is being claimed.N/AYes
networkThe blockchain on which the claim admin process will be executed. Examples include avalancheFuji, ethereumSepolia, baseSepolia, and arbitrumSepolia.N/AYes

Claim the admin role by using the following commands, replacing the token address with the one you deployed in the previous steps:

  1. Claim the admin role on Avalanche Fuji:

    npx hardhat claimAdmin --tokenaddress 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 --network avalancheFuji

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:17:16.402Z info: 🎯 Claiming admin for 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 using getCCIPAdmin mode
2025-10-22T13:17:20.129Z info: ✅ Current wallet 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca is CCIP admin
2025-10-22T13:17:22.182Z info: 📤 TX sent: 0xf64560bd40a848ecf26b3d63699cfcbd56154c36851eaa3e5aab4e4d338197a7. Waiting for 2 confirmations...
2025-10-22T13:17:31.204Z info: ✅ Admin claimed for 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 on avalancheFuji (2 confirmations)

  2. Claim the admin role on Ethereum Sepolia:

    npx hardhat claimAdmin --tokenaddress 0xb613B55897F07eAF430bF9a509498e55487305Ea --network ethereumSepolia

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:18:41.832Z info: 🎯 Claiming admin for 0xb613B55897F07eAF430bF9a509498e55487305Ea using getCCIPAdmin mode
2025-10-22T13:18:48.580Z info: ✅ Current wallet 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca is CCIP admin
2025-10-22T13:18:51.544Z info: 📤 TX sent: 0xc27012ea91ec4c3f6898c5bd4ad7f7ff390c0030fa87a6692869c6acd96b5417. Waiting for 3 confirmations...
2025-10-22T13:19:27.189Z info: ✅ Admin claimed for 0xb613B55897F07eAF430bF9a509498e55487305Ea on ethereumSepolia (3 confirmations)

Accept Admin Role

In this step, you will use the acceptAdminRole task to accept the admin role for the deployed tokens on both testnets, Avalanche Fuji and Ethereum Sepolia. Once you have claimed the role, accepting the role finalizes your control over the token administration.

Below is an explanation of the parameters used during the admin role acceptance process:

ParameterDescriptionDefaultRequired
tokenaddressThe address of the token for which the admin role is being accepted.N/AYes
networkThe blockchain on which the accept admin process will be executed. Examples include avalancheFuji, ethereumSepolia, baseSepolia, and arbitrumSepolia.N/AYes

Accept the admin role by using the following commands, replacing the token address with the one deployed in the previous steps:

  1. Accept the admin role on Avalanche Fuji:

    npx hardhat acceptAdminRole --tokenaddress 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 --network avalancheFuji

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:21:31.047Z info: 🔄 Accepting admin role for 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 on avalancheFuji...
2025-10-22T13:21:34.256Z info: Checking pending admin for 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5...
2025-10-22T13:21:34.530Z info: ✅ Current wallet 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca is the pending admin
2025-10-22T13:21:34.530Z info: Accepting admin role...
2025-10-22T13:21:36.591Z info: 📤 TX sent: 0xb4bd7a1fb2803c6e4459e44c014cb450bd7e0149b2d9fc8018eb1a57561600c2. Waiting for 2 confirmations...
2025-10-22T13:21:41.413Z info: ✅ Admin role accepted for 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 on avalancheFuji (2 confirmations)

  2. Accept the admin role on Ethereum Sepolia:

    npx hardhat acceptAdminRole --tokenaddress 0xb613B55897F07eAF430bF9a509498e55487305Ea --network ethereumSepolia

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:22:24.437Z info: 🔄 Accepting admin role for 0xb613B55897F07eAF430bF9a509498e55487305Ea on ethereumSepolia...
2025-10-22T13:22:29.165Z info: Checking pending admin for 0xb613B55897F07eAF430bF9a509498e55487305Ea...
2025-10-22T13:22:29.467Z info: ✅ Current wallet 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca is the pending admin
2025-10-22T13:22:29.467Z info: Accepting admin role...
2025-10-22T13:22:31.790Z info: 📤 TX sent: 0x57094dfdb13ab712fb1afb099c6c65734a7726939863626ec6a59d0c24326e89. Waiting for 3 confirmations...
2025-10-22T13:23:26.623Z info: ✅ Admin role accepted for 0xb613B55897F07eAF430bF9a509498e55487305Ea on ethereumSepolia (3 confirmations)

Set Pool

In this step, you will use the setPool task to link each token with its respective token pool on both testnets.

Below is an explanation of the parameters used during the pool setting process:

ParameterDescriptionDefaultRequired
tokenaddressThe address of the token to be linked to a pool.N/AYes
pooladdressThe address of the pool associated with the token.N/AYes
networkThe blockchain on which the pool setting will be executed. Examples include avalancheFuji, ethereumSepolia, baseSepolia, and arbitrumSepolia.N/AYes

Link each token with its respective token pool by using the following commands, replacing the token and pool addresses with the ones you deployed in the previous steps:

  1. Set the pool for Avalanche Fuji:

    npx hardhat setPool \
  --tokenaddress 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 --pooladdress 0x10db2Fd0A5E3e9F68c72ae99CC266f383c1814a2 \
  --network avalancheFuji

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:26:57.003Z info: 🔗 Setting pool for token 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 on avalancheFuji...
2025-10-22T13:27:00.453Z info: 🔹 Using signer: 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca
2025-10-22T13:27:00.453Z info: Using TokenAdminRegistry: 0xA92053a4a3922084d992fD2835bdBa4caC6877e6
2025-10-22T13:27:00.909Z info: Checking token configuration for 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5...
2025-10-22T13:27:01.184Z info: Token 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 current admin: 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
2025-10-22T13:27:01.185Z info: ✅ Current wallet 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca is the token administrator
2025-10-22T13:27:01.185Z info: Setting pool 0x10db2Fd0A5E3e9F68c72ae99CC266f383c1814a2 for token 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5...
2025-10-22T13:27:03.433Z info: 📤 TX sent: 0xddbf3e5a7d0799ccf11fff3ad816553c75be8cc0d2986d0a49d26c271af040e9. Waiting for 2 confirmations...
2025-10-22T13:27:12.509Z info: ✅ Pool successfully set for token 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 → 0x10db2Fd0A5E3e9F68c72ae99CC266f383c1814a2 on avalancheFuji (2 confirmations)

  2. Set the pool for Ethereum Sepolia:

    npx hardhat setPool \
  --tokenaddress 0xb613B55897F07eAF430bF9a509498e55487305Ea --pooladdress 0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A \
  --network ethereumSepolia

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:27:52.517Z info: 🔗 Setting pool for token 0xb613B55897F07eAF430bF9a509498e55487305Ea on ethereumSepolia...
2025-10-22T13:27:59.751Z info: 🔹 Using signer: 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca
2025-10-22T13:27:59.751Z info: Using TokenAdminRegistry: 0x95F29FEE11c5C55d26cCcf1DB6772DE953B37B82
2025-10-22T13:28:00.123Z info: Checking token configuration for 0xb613B55897F07eAF430bF9a509498e55487305Ea...
2025-10-22T13:28:00.533Z info: Token 0xb613B55897F07eAF430bF9a509498e55487305Ea current admin: 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
2025-10-22T13:28:00.533Z info: ✅ Current wallet 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca is the token administrator
2025-10-22T13:28:00.533Z info: Setting pool 0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A for token 0xb613B55897F07eAF430bF9a509498e55487305Ea...
2025-10-22T13:28:03.981Z info: 📤 TX sent: 0xdf9eaf86d6250590e2dffcd69f2e0e6a6bcdf41a1e0ab549437e74f0b4f2e02e. Waiting for 3 confirmations...
2025-10-22T13:28:40.100Z info: ✅ Pool successfully set for token 0xb613B55897F07eAF430bF9a509498e55487305Ea → 0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A on ethereumSepolia (3 confirmations)

Configure Token Pools

In this step, you will use the applyChainUpdates task to initialize the token pool configuration on each blockchain to enable cross-chain transfers between Avalanche Fuji and Ethereum Sepolia. Below is an explanation of the parameters used:

ParameterDescriptionDefaultRequired
pooladdressThe address of the pool to be configured.N/AYes
remotechainThe remote blockchain network (e.g., ethereumSepolia for Fuji pool, avalancheFuji for Sepolia pool).N/AYes
remotepooladdressesComma-separated list of remote pool addresses.N/AYes
remotetokenaddressThe address of the token on the remote chain.N/AYes
outboundratelimitenabledFlag to enable outbound rate limits for cross-chain transfers. Pass this flag to enable, omit to disable.falseNo
outboundratelimitcapacityMaximum capacity for the outbound rate limiter (in wei).0No
outboundratelimitrateRefill rate for the outbound rate limiter bucket (tokens per second, in wei).0No
inboundratelimitenabledFlag to enable inbound rate limits for cross-chain transfers. Pass this flag to enable, omit to disable.falseNo
inboundratelimitcapacityMaximum capacity for the inbound rate limiter (in wei).0No
inboundratelimitrateRefill rate for the inbound rate limiter bucket (tokens per second, in wei).0No

Configure the pools using the following commands, replacing the pool, token, and remote pool addresses with those you deployed in the previous steps:

  1. Configure the pool on Avalanche Fuji:

    npx hardhat applyChainUpdates \
  --pooladdress 0x10db2Fd0A5E3e9F68c72ae99CC266f383c1814a2 \
  --remotechain ethereumSepolia \
  --remotepooladdresses 0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A \
  --remotetokenaddress 0xb613B55897F07eAF430bF9a509498e55487305Ea \
  --network avalancheFuji

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:32:32.607Z info: === Starting Chain Update Configuration ===
2025-10-22T13:32:32.607Z info: 🔹 Local network: avalancheFuji
2025-10-22T13:32:32.608Z info: 🔹 Pool address: 0x10db2Fd0A5E3e9F68c72ae99CC266f383c1814a2
2025-10-22T13:32:32.608Z info: 🔹 Remote chain: ethereumSepolia
2025-10-22T13:32:32.608Z info: 🔹 Remote chain family: evm
2025-10-22T13:32:32.608Z info: 🔹 Remote chain selector: 16015286601757825753
2025-10-22T13:32:34.967Z info: ✅ All addresses validated successfully
2025-10-22T13:32:35.511Z info: ✅ Using signer: 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca
2025-10-22T13:32:35.920Z info: ✅ Connected to TokenPool contract
2025-10-22T13:32:35.921Z info:   Remote pool 1: 0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A → 0x0000000000000000000000005e8b0e5eac57d73e7b93d85b8ea3fcada282868a
2025-10-22T13:32:35.922Z info: === Rate Limiter Configuration ===
2025-10-22T13:32:35.922Z info: Outbound enabled: false
2025-10-22T13:32:35.922Z info: Inbound enabled: false
2025-10-22T13:32:35.922Z info: === Executing applyChainUpdates() ===
2025-10-22T13:32:38.130Z info: 📤 TX sent: 0x74cbcaf2bbd5fa86f7a72a58f2f289496f3cba10d1d99d3638e7dae1e30d8ded
2025-10-22T13:32:38.130Z info: Waiting for 2 confirmations...
2025-10-22T13:32:47.218Z info: ✅ Chain update applied successfully on avalancheFuji (2 confirmations)!

  2. Configure the pool on Ethereum Sepolia:

    npx hardhat applyChainUpdates \
  --pooladdress 0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A \
  --remotechain avalancheFuji \
  --remotepooladdresses 0x10db2Fd0A5E3e9F68c72ae99CC266f383c1814a2 \
  --remotetokenaddress 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 \
  --network ethereumSepolia

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:33:45.900Z info: === Starting Chain Update Configuration ===
2025-10-22T13:33:45.901Z info: 🔹 Local network: ethereumSepolia
2025-10-22T13:33:45.901Z info: 🔹 Pool address: 0x5e8b0e5EAC57d73E7b93d85b8eA3fcaDa282868A
2025-10-22T13:33:45.901Z info: 🔹 Remote chain: avalancheFuji
2025-10-22T13:33:45.901Z info: 🔹 Remote chain family: evm
2025-10-22T13:33:45.901Z info: 🔹 Remote chain selector: 14767482510784806043
2025-10-22T13:33:48.062Z info: ✅ All addresses validated successfully
2025-10-22T13:33:48.655Z info: ✅ Using signer: 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca
2025-10-22T13:33:48.977Z info: ✅ Connected to TokenPool contract
2025-10-22T13:33:48.980Z info:   Remote pool 1: 0x10db2Fd0A5E3e9F68c72ae99CC266f383c1814a2 → 0x00000000000000000000000010db2fd0a5e3e9f68c72ae99cc266f383c1814a2
2025-10-22T13:33:48.980Z info: === Rate Limiter Configuration ===
2025-10-22T13:33:48.980Z info: Outbound enabled: false
2025-10-22T13:33:48.980Z info: Inbound enabled: false
2025-10-22T13:33:48.981Z info: === Executing applyChainUpdates() ===
2025-10-22T13:33:51.061Z info: 📤 TX sent: 0x16b5122c3687a81b71e0ac479dfae846dc5eb8091d85dc51c137f8aa0e6d0bec
2025-10-22T13:33:51.061Z info: Waiting for 3 confirmations...
2025-10-22T13:34:27.345Z info: ✅ Chain update applied successfully on ethereumSepolia (3 confirmations)!

Mint Tokens

In this step, you will use the mintTokens task to mint tokens on Avalanche Fuji for your Externally Owned Account (EOA). Since you assigned mint and burn privileges to your EOA when deploying the tokens in the first step, you can now mint tokens for testing purposes. This is to ensure that you have enough tokens in your EOA to perform cross-chain transfers in the next step.

You will interact with the BurnMintERC20 token contract, specifically calling the mint() function to mint tokens to your EOA.

Below is an explanation of the parameters used during the minting process:

ParameterDescriptionDefaultRequired
tokenaddressThe address of the token for which tokens are being minted.N/AYes
amountThe amount of tokens to mint (in wei).N/AYes
receiveraddressThe address of the receiver of the minted tokens. If not provided, defaults to your EOA.N/ANo
networkThe blockchain on which the minting process will be executed. Examples include avalancheFuji, ethereumSepolia, baseSepolia, and arbitrumSepolia.N/AYes

Mint tokens to your EOA using the following command, replacing the token address with the one you deployed in the previous steps:

  1. Mint tokens on Avalanche Fuji:

    npx hardhat mintTokens --tokenaddress 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 --amount 1000000000000000000000 --network avalancheFuji

    Example output:

    ✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:37:15.433Z info: 🪙 Minting 1000000000000000000000 BnMsak to 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca...
2025-10-22T13:37:17.440Z info: ⏳ Mint tx: 0x4e4519f97c773a351132a068f55a0ced2c25bcf7a9587c83b338403b17cdb5bc
2025-10-22T13:37:17.441Z info:    Waiting for 2 confirmation(s)...
2025-10-22T13:37:31.076Z info: ✅ Minted 1000000000000000000000 BnMsak to 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca
2025-10-22T13:37:31.076Z info:    Current balance of 0x8c244f0b2164e6a3bed74ab429b0ebd661bb14ca: 1100000000000000000000 BnMsak

Transfer Tokens

In this step, you will use the transferTokens task to transfer tokens from Avalanche Fuji to Ethereum Sepolia using CCIP. You have two options for paying CCIP fees: using LINK tokens or native gas tokens.

You will interact with the IRouterClient contract, specifically calling the ccipSend() function to initiate the token transfer.

Below is an explanation of the parameters used during the token transfer process:

ParameterDescriptionDefaultRequired
tokenaddressThe address of the token being transferred.N/AYes
amountThe amount of tokens to transfer.N/AYes
destinationchainThe blockchain to which the tokens will be transferred. Examples include avalancheFuji, ethereumSepolia, baseSepolia, and arbitrumSepolia.N/AYes
receiveraddressThe address of the receiver on the destination blockchain.N/AYes
feeThe type of fee used for the transfer, either LINK or native.LINKNo
networkThe blockchain on which the token transfer will be initiated. Examples include avalancheFuji, ethereumSepolia, baseSepolia, and arbitrumSepolia.N/AYes

Call the CCIP Router to transfer tokens from Avalanche Fuji to Ethereum Sepolia, paying the CCIP fees in LINK tokens. Replace the token address, amount, receiver address, and blockchain with the appropriate values:

npx hardhat transferTokens --tokenaddress 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 --amount 100000000000000000000 --destinationchain ethereumSepolia --receiveraddress 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf --network avalancheFuji

Example output:

✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:43:39.126Z info: 🚀 Transferring 100000000000000000000 tokens via CCIP from avalancheFuji to ethereumSepolia...
2025-10-22T13:43:39.127Z info:    Token: 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5
2025-10-22T13:43:39.127Z info:    Receiver: 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf
2025-10-22T13:43:39.127Z info:    Fee token: LINK
2025-10-22T13:43:40.097Z info: 💰 Estimated fees: 12762338383426833
2025-10-22T13:43:40.351Z info: Approving 100000000000000000000 tokens for router 0xF694E193200268f9a4868e4Aa017A0118C9a8177
2025-10-22T13:43:42.411Z info:    Waiting for 2 confirmation(s)...
2025-10-22T13:43:56.306Z info: Approving 12762338383426833 LINK to router
2025-10-22T13:43:57.544Z info:    Waiting for 2 confirmation(s)...
2025-10-22T13:44:02.292Z info: 💰 Estimated CCIP fees: 12762338383426833
2025-10-22T13:44:02.292Z info: Simulating CCIP message...
2025-10-22T13:44:02.549Z info: Sending CCIP message...
2025-10-22T13:44:03.813Z info: ⏳ CCIP message tx: 0x3518d5469eed57cece65221c69d071be9aa883035e7869a24d2f75061f789926
2025-10-22T13:44:03.813Z info:    Waiting for 2 confirmation(s)...
2025-10-22T13:44:08.811Z info: ✅ CCIP message sent successfully
2025-10-22T13:44:08.812Z info:    Transaction: 0x3518d5469eed57cece65221c69d071be9aa883035e7869a24d2f75061f789926
2025-10-22T13:44:08.812Z info:    Check status: https://ccip.chain.link/tx/0x3518d5469eed57cece65221c69d071be9aa883035e7869a24d2f75061f789926
2025-10-22T13:44:08.812Z info: 📋 Transfer Summary:
2025-10-22T13:44:08.813Z info:    Token: 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5
2025-10-22T13:44:08.813Z info:    Amount: 100000000000000000000
2025-10-22T13:44:08.813Z info:    From: avalancheFuji
2025-10-22T13:44:08.813Z info:    To: ethereumSepolia
2025-10-22T13:44:08.813Z info:    Receiver: 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf
2025-10-22T13:44:08.813Z info:    Fee paid in: LINK

Pay fees in native gas tokens

Call the CCIP Router to transfer tokens from Avalanche Fuji to Ethereum Sepolia, paying the CCIP fees in native gas tokens. Replace the token address, amount, receiver address, and blockchain with the appropriate values:

npx hardhat transferTokens --tokenaddress 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5 --amount 100000000000000000000 --destinationchain ethereumSepolia --receiveraddress 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf --fee native --network avalancheFuji

Example output:

✅ Tasks loaded from /tasks/index.ts
2025-10-22T13:47:59.281Z info: 🚀 Transferring 100000000000000000000 tokens via CCIP from avalancheFuji to ethereumSepolia...
2025-10-22T13:47:59.283Z info:    Token: 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5
2025-10-22T13:47:59.283Z info:    Receiver: 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf
2025-10-22T13:47:59.284Z info:    Fee token: native
2025-10-22T13:48:00.223Z info: 💰 Estimated fees: 12717027432412391
2025-10-22T13:48:00.489Z info: Approving 100000000000000000000 tokens for router 0xF694E193200268f9a4868e4Aa017A0118C9a8177
2025-10-22T13:48:02.490Z info:    Waiting for 2 confirmation(s)...
2025-10-22T13:48:15.961Z info: 💰 Estimated CCIP fees: 12717027432412391
2025-10-22T13:48:15.962Z info: Simulating CCIP message...
2025-10-22T13:48:16.222Z info: Sending CCIP message...
2025-10-22T13:48:17.524Z info: ⏳ CCIP message tx: 0x870904c7d9e758934ab468fd0889f078a7800fdf074242ccbbbac2d9cc0a257e
2025-10-22T13:48:17.524Z info:    Waiting for 2 confirmation(s)...
2025-10-22T13:48:22.556Z info: ✅ CCIP message sent successfully
2025-10-22T13:48:22.556Z info:    Transaction: 0x870904c7d9e758934ab468fd0889f078a7800fdf074242ccbbbac2d9cc0a257e
2025-10-22T13:48:22.556Z info:    Check status: https://ccip.chain.link/tx/0x870904c7d9e758934ab468fd0889f078a7800fdf074242ccbbbac2d9cc0a257e
2025-10-22T13:48:22.556Z info: 📋 Transfer Summary:
2025-10-22T13:48:22.556Z info:    Token: 0xa3B8d1648A9f9515b2F2EefC7222c62AEAAC9ce5
2025-10-22T13:48:22.556Z info:    Amount: 100000000000000000000
2025-10-22T13:48:22.556Z info:    From: avalancheFuji
2025-10-22T13:48:22.556Z info:    To: ethereumSepolia
2025-10-22T13:48:22.557Z info:    Receiver: 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf
2025-10-22T13:48:22.557Z info:    Fee paid in: native

Your tokens have been locked on the token pool on Avalanche Fuji, the corresponding tokens have been minted on Ethereum Sepolia and sent to your receiver address.

Note: Since your Lock & Release token pool on Avalanche Fuji has locked some tokens, you can transfer tokens from Ethereum Sepolia to Avalanche Fuji using CCIP as an exercise. Your tokens will be burned on Ethereum Sepolia, and the corresponding tokens will be released on Avalanche Fuji. Make sure not to transfer more tokens than the amount of tokens locked in the token pool on Avalanche Fuji.

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