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.

Hardhat (Lock & Mint)

Hardhat (Lock & Mint) Foundry (Lock & Mint)

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 v18 or above installed. If not, install Node.js v18:
   Download Node.js 18 if you don't have it installed. Optionally, you can use the nvm package to switch between Node.js versions:

   nvm use 18
   

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

   node -v
   

   Example output:

   $ node -v
   v18.7.0
   

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 Arbitrum 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.
      • ARBITRUM_SEPOLIA_RPC_URL: A URL for the Arbitrum 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.
      • ARBISCAN_API_KEY: An API key from Arbiscan to verify your contracts on Arbitrum. See this guide to get one from Arbiscan.

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 Arbitrum 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.ts task to deploy tokens on two testnets, Avalanche Fuji and Arbitrum Sepolia. Below is an explanation of the parameters used during deployment:

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 aem" --symbol BnMaem --decimals 18 --maxsupply 0 --premint 100000000000000000000 --verifycontract true --network avalancheFuji
   

   Example output:

   2025-05-15T02:37:00.663Z info: Deploying BurnMintERC20 contract to avalancheFuji
   2025-05-15T02:37:00.664Z info: Waiting 2 blocks for transaction 0x11ea95f8f13f87b99b90e81b35da9268805816f0c945a0d987fe0c4c32a3042d to be confirmed...
   2025-05-15T02:37:01.330Z info: Token deployed to: 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054
   2025-05-15T02:37:01.881Z info: Granting mint and burn roles to 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T02:37:09.923Z info: Verifying contract...
   The contract 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 has already been verified on the block explorer. If you're trying to verify a partially verified contract, please use the --force flag.
   https://testnet.snowtrace.io/address/0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054#code
   
   2025-05-15T02:37:11.266Z info: Token contract deployed and verified
   

2. Deploy the token on Arbitrum Sepolia:

   npx hardhat deployToken --name "BnM aem" --symbol BnMaem --decimals 18 --maxsupply 0 --premint 100000000000000000000 --verifycontract true --network arbitrumSepolia
   

   Example output:

   2025-05-15T02:38:38.539Z info: Deploying BurnMintERC20 contract to arbitrumSepolia
   2025-05-15T02:38:38.540Z info: Waiting 2 blocks for transaction 0x993d5c5371fcc611a2cc4f246ebd3e58591bc49f549ff25a9880dd13e3c7848f to be confirmed...
   2025-05-15T02:38:38.851Z info: Token deployed to: 0x528f08cF0b8541CdFeE5E897c861348AE601315e
   2025-05-15T02:38:39.014Z info: Granting mint and burn roles to 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T02:38:42.435Z info: Verifying contract...
   The contract 0x528f08cF0b8541CdFeE5E897c861348AE601315e has already been verified on the block explorer. If you're trying to verify a partially verified contract, please use the --force flag.
   https://sepolia.arbiscan.io/address/0x528f08cF0b8541CdFeE5E897c861348AE601315e#code
   
   2025-05-15T02:38:43.668Z info: Token contract deployed and verified
   

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 Arbitrum Sepolia. Below is an explanation of the parameters used during deployment:

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 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 \
     --pooltype lockRelease \
     --localtokendecimals 18 \
     --acceptliquidity false \
     --verifycontract true \
     --network avalancheFuji
   

   Example output:

   2025-05-15T02:41:28.385Z info: Waiting 2 blocks for transaction 0x8d5a04279c14dbabf0b7ee4f1821b9c789ce87c53c75f436cd046cd019e200ed to be confirmed...
   2025-05-15T02:41:29.449Z info: Token pool deployed to: 0xdA99b1551F0E69aC11FD4C36731F079Ca3131a8F
   2025-05-15T02:41:29.449Z info: Verifying contract...
   Successfully submitted source code for contract
   @chainlink/contracts-ccip/contracts/pools/LockReleaseTokenPool.sol:LockReleaseTokenPool at 0xdA99b1551F0E69aC11FD4C36731F079Ca3131a8F
   for verification on the block explorer. Waiting for verification result...
   
   Successfully verified contract LockReleaseTokenPool on the block explorer.
   https://testnet.snowtrace.io/address/0xdA99b1551F0E69aC11FD4C36731F079Ca3131a8F#code
   
   2025-05-15T02:42:12.868Z info: Token pool contract deployed and verified
   

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

   npx hardhat deployTokenPool \
     --tokenaddress 0x528f08cF0b8541CdFeE5E897c861348AE601315e \
     --pooltype burnMint \
     --localtokendecimals 18 \
     --verifycontract true \
     --network arbitrumSepolia
   

   Example output:

   2025-05-15T02:44:04.693Z info: Waiting 2 blocks for transaction 0xdcb0485b605e4cf3a95fab8aa5355c891bc6715d5dd37211e4f4145e89277d6b to be confirmed...
   2025-05-15T02:44:05.018Z info: Token pool deployed to: 0x85EDf5dE3417c240f8E008D6B1377403eF17BE10
   2025-05-15T02:44:05.019Z info: Granting mint and burn roles to 0x85EDf5dE3417c240f8E008D6B1377403eF17BE10 on token 0x528f08cF0b8541CdFeE5E897c861348AE601315e
   2025-05-15T02:44:08.667Z info: Verifying contract...
   The contract 0x85EDf5dE3417c240f8E008D6B1377403eF17BE10 has already been verified on the block explorer. If you're trying to verify a partially verified contract, please use the --force flag.
   https://sepolia.arbiscan.io/address/0x85EDf5dE3417c240f8E008D6B1377403eF17BE10#code
   
   2025-05-15T02:44:09.814Z info: Token pool contract deployed and verified
   

Claim Admin

In this step, you will use the claimAdmin.ts task to register your EOA as the administrator for the deployed tokens on both testnets, Avalanche Fuji and Arbitrum 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:

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 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 --network avalancheFuji
   

   Example output:

   2025-05-15T07:43:26.364Z info: Current token admin: 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T07:43:26.365Z info: Claiming admin of 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 via getCCIPAdmin() for CCIP admin 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T07:43:35.471Z info: Claimed admin of 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 tx: 0x2cc45f61521f4cce83dab2c8c452ad87cc4867195f6ad2da810b6ab85f45ac8d
   

2. Claim the admin role on Arbitrum Sepolia:

   npx hardhat claimAdmin --tokenaddress 0x528f08cF0b8541CdFeE5E897c861348AE601315e --network arbitrumSepolia
   

   Example output:

   2025-05-15T07:46:04.941Z info: Current token admin: 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T07:46:04.942Z info: Claiming admin of 0x528f08cF0b8541CdFeE5E897c861348AE601315e via getCCIPAdmin() for CCIP admin 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T07:46:08.656Z info: Claimed admin of 0x528f08cF0b8541CdFeE5E897c861348AE601315e tx: 0x6b0a1ba03885609d51d4d53159feb5d0a65993a3276fc1b875153d7c2e1208e0
   

Accept Admin Role

In this step, you will use the acceptAdminRole.ts task to accept the admin role for the deployed tokens on both testnets, Avalanche Fuji and Arbitrum 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:

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 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 --network avalancheFuji
   

   Example output:

   2025-05-15T07:48:10.397Z info: Accepted admin role for token 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 tx: 0x65e6ca78912e892aa12dfd89a2f81cd16bea190ed27c2387eeb25b8825ddc871
   

2. Accept the admin role on Arbitrum Sepolia:

   npx hardhat acceptAdminRole --tokenaddress 0x528f08cF0b8541CdFeE5E897c861348AE601315e --network arbitrumSepolia
   

   Example output:

   2025-05-15T07:49:32.507Z info: Accepted admin role for token 0x528f08cF0b8541CdFeE5E897c861348AE601315e tx: 0x37115cd24457bd40102bff9e9e6e7725c380dfbf1dd9cbcfa7dc767757cc64c2
   

Set Pool

In this step, you will use the setPool.ts 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:

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 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 --pooladdress 0xdA99b1551F0E69aC11FD4C36731F079Ca3131a8F \
     --network avalancheFuji
   

   Example output:

   2025-05-15T07:51:53.865Z info: Setting pool for token 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 to 0xdA99b1551F0E69aC11FD4C36731F079Ca3131a8F by 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T07:52:02.833Z info: Pool set for token 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 to 0xdA99b1551F0E69aC11FD4C36731F079Ca3131a8F
   

2. Set the pool for Arbitrum Sepolia:

   npx hardhat setPool \
     --tokenaddress 0x528f08cF0b8541CdFeE5E897c861348AE601315e --pooladdress 0x85EDf5dE3417c240f8E008D6B1377403eF17BE10 \
     --network arbitrumSepolia
   

   Example output:

   2025-05-15T07:53:01.750Z info: Setting pool for token 0x528f08cF0b8541CdFeE5E897c861348AE601315e to 0x85EDf5dE3417c240f8E008D6B1377403eF17BE10 by 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T07:53:06.764Z info: Pool set for token 0x528f08cF0b8541CdFeE5E897c861348AE601315e to 0x85EDf5dE3417c240f8E008D6B1377403eF17BE10
   

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 Arbitrum Sepolia. Below is an explanation of the parameters used:

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 0xdA99b1551F0E69aC11FD4C36731F079Ca3131a8F \
     --remotechain arbitrumSepolia \
     --remotepooladdresses 0x85EDf5dE3417c240f8E008D6B1377403eF17BE10 \
     --remotetokenaddress 0x528f08cF0b8541CdFeE5E897c861348AE601315e \
     --network avalancheFuji
   

   Example output:

   2025-05-15T07:56:37.082Z info: Applying chain update to pool at address: 0xdA99b1551F0E69aC11FD4C36731F079Ca3131a8F
   2025-05-15T07:56:37.082Z info: Remote chain: arbitrumSepolia (3478487238524512106)
   2025-05-15T07:56:37.082Z info: Remote pool addresses: 0x85EDf5dE3417c240f8E008D6B1377403eF17BE10
   2025-05-15T07:56:37.082Z info: Remote token address: 0x528f08cF0b8541CdFeE5E897c861348AE601315e
   2025-05-15T07:56:43.745Z info: Chain update applied successfully
   

2. Configure the pool on Arbitrum Sepolia:

   npx hardhat applyChainUpdates \
     --pooladdress 0x85EDf5dE3417c240f8E008D6B1377403eF17BE10 \
     --remotechain avalancheFuji \
     --remotepooladdresses 0xdA99b1551F0E69aC11FD4C36731F079Ca3131a8F \
     --remotetokenaddress 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 \
     --network arbitrumSepolia
   

   Example output:

   2025-05-15T07:57:31.979Z info: Applying chain update to pool at address: 0x85EDf5dE3417c240f8E008D6B1377403eF17BE10
   2025-05-15T07:57:31.980Z info: Remote chain: avalancheFuji (14767482510784806043)
   2025-05-15T07:57:31.980Z info: Remote pool addresses: 0xdA99b1551F0E69aC11FD4C36731F079Ca3131a8F
   2025-05-15T07:57:31.980Z info: Remote token address: 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054
   2025-05-15T07:57:36.087Z info: Chain update applied successfully
   

Mint Tokens

In this step, you will use the mintTokens.ts 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:

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 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 --amount 1000000000000000000000 --network avalancheFuji
   

   Example output:

   2025-05-15T07:59:50.241Z info: Minting 1000000000000000000000 of BnMaem tokens to 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T07:59:59.473Z info: Minted 1000000000000000000000 of BnMaem tokens to 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA - transaction hash: 0xac6ff86fe7a8a948701c2473586f73b0311ada7452bfd82ff5938dccc4f2d9cc
   2025-05-15T07:59:59.808Z info: Current balance of 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA is 1100000000000000000000 BnMaem
   

Transfer Tokens

In this step, you will use the transferTokens task to transfer tokens from Avalanche Fuji to Arbitrum 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:

Pay fees in LINK

Call the CCIP Router to transfer tokens from Avalanche Fuji to Arbitrum 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 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 --amount 100000000000000000000 --destinationchain arbitrumSepolia --receiveraddress 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf --network avalancheFuji

Example output:

2025-05-15T08:03:22.279Z info: Estimated fees: 22167517387804854
2025-05-15T08:03:22.280Z info: Approving 100000000000000000000 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 to 0xF694E193200268f9a4868e4Aa017A0118C9a8177
2025-05-15T08:03:27.907Z info: Approving 22167517387804854 LINK to 0xF694E193200268f9a4868e4Aa017A0118C9a8177
2025-05-15T08:03:36.529Z info: Transferring 100000000000000000000 of 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 to 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf on chain arbitrumSepolia with 22167517387804854 of LINK as fees
2025-05-15T08:03:40.665Z info: Transaction hash: 0xedad6bd09fbb9d99282f3875e6abebfff739aaf01d7490ba471b9f372ff70c5e
2025-05-15T08:03:40.681Z warn: Unable to parse the event logs corresponding to the transaction 0xedad6bd09fbb9d99282f3875e6abebfff739aaf01d7490ba471b9f372ff70c5e
2025-05-15T08:03:40.681Z info: Check status of message on https://ccip.chain.link/tx/0xedad6bd09fbb9d99282f3875e6abebfff739aaf01d7490ba471b9f372ff70c5e

Pay fees in native gas tokens

Call the CCIP Router to transfer tokens from Avalanche Fuji to Arbitrum 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 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 --amount 100000000000000000000 --destinationchain arbitrumSepolia --receiveraddress 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf --fee native --network avalancheFuji

Example output:

2025-05-15T08:05:15.654Z info: Estimated fees: 15603670276848872
2025-05-15T08:05:15.659Z info: Approving 100000000000000000000 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 to 0xF694E193200268f9a4868e4Aa017A0118C9a8177
2025-05-15T08:05:25.788Z info: Transferring 100000000000000000000 of 0x6cdB459EaCB30947Db2a4374a78d37A8FCe11054 to 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf on chain arbitrumSepolia with 15603670276848872 of native token as fees
2025-05-15T08:05:30.584Z info: Transaction hash: 0x892be0e1c6617d0e7bfb08dd93f88833d699470869f8b05520e9624ce8c125d8
2025-05-15T08:05:30.602Z warn: Unable to parse the event logs corresponding to the transaction 0x892be0e1c6617d0e7bfb08dd93f88833d699470869f8b05520e9624ce8c125d8
2025-05-15T08:05:30.602Z info: Check status of message on https://ccip.chain.link/tx/0x892be0e1c6617d0e7bfb08dd93f88833d699470869f8b05520e9624ce8c125d8

Your tokens have been locked on the token pool on Avalanche Fuji, the corresponding tokens have been minted on Arbitrum 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 Arbitrum Sepolia to Avalanche Fuji using CCIP as an exercise. Your tokens will be burned on Arbitrum 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.