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

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Hardhat (Burn & Mint)

Hardhat (Burn & Mint) Foundry (Burn & 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 and set up Burn & Mint token pools. After that, you will register them in CCIP and configure them without needing manual intervention. Finally, you will test the Burn & Mint token handling mechanism, where tokens are burned 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 BurnMintTokenPool token pools on Avalanche Fuji and Arbitrum Sepolia. These pools are essential for minting and burning tokens during cross-chain transfers. 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 token pools, allowing your token pools to control how tokens are minted and burned 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 Arbitrum explorer API key, used to verify your contract. Follow 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 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:

   2025-05-15T00:36:53.652Z info: Deploying BurnMintERC20 contract to avalancheFuji
   2025-05-15T00:36:53.653Z info: Waiting 2 blocks for transaction 0xe1db85d7f7a1d0afb3da14cb0b426316b9944d2e594200bde6f4bdc8574789a5 to be confirmed...
   2025-05-15T00:36:54.657Z info: Token deployed to: 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef
   2025-05-15T00:36:54.817Z info: Granting mint and burn roles to 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T00:37:00.993Z info: Verifying contract...
   The contract 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef 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/0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef#code
   
   2025-05-15T00:37:02.350Z 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:

   2025-05-15T00:40:39.000Z info: Deploying BurnMintERC20 contract to arbitrumSepolia
   2025-05-15T00:40:39.001Z info: Waiting 2 blocks for transaction 0xae7b73371e0c0054587c6e50c0a835a4b5ce2cab173e0803f8ac9c56f986fc3b to be confirmed...
   2025-05-15T00:40:39.575Z info: Token deployed to: 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213
   2025-05-15T00:40:39.790Z info: Granting mint and burn roles to 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T00:40:43.010Z info: Verifying contract...
   The contract 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 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/0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213#code
   
   2025-05-15T00:40:44.163Z 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 burn and mint token pool on Avalanche Fuji:

   npx hardhat deployTokenPool \
     --tokenaddress 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef \
     --pooltype burnMint \
     --localtokendecimals 18 \
     --verifycontract true \
     --network avalancheFuji
   

   Example output:

   2025-05-15T00:44:46.294Z info: Waiting 2 blocks for transaction 0x339c04b48a4870f49efe593e149fb954df8fd05dddb56463dcf08f99ccab166e to be confirmed...
   2025-05-15T00:44:46.979Z info: Token pool deployed to: 0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047
   2025-05-15T00:44:46.980Z info: Granting mint and burn roles to 0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047 on token 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef
   2025-05-15T00:44:56.086Z info: Verifying contract...
   The contract 0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047 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/0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047#code
   
   2025-05-15T00:44:57.878Z info: Token pool contract deployed and verified
   

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

   npx hardhat deployTokenPool \
     --tokenaddress 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 \
     --pooltype burnMint \
     --localtokendecimals 18 \
     --verifycontract true \
     --network arbitrumSepolia
   

   Example output:

   2025-05-15T00:47:04.761Z info: Waiting 2 blocks for transaction 0x6ec7377c986464a2993d0bdb94bb236ee9da90582a403eeaec02805ead8fecf9 to be confirmed...
   2025-05-15T00:47:05.082Z info: Token pool deployed to: 0x74F0842a9A55575e8e36692c356292a812640F67
   2025-05-15T00:47:05.082Z info: Granting mint and burn roles to 0x74F0842a9A55575e8e36692c356292a812640F67 on token 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213
   2025-05-15T00:47:08.849Z info: Verifying contract...
   The contract 0x74F0842a9A55575e8e36692c356292a812640F67 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/0x74F0842a9A55575e8e36692c356292a812640F67#code
   
   2025-05-15T00:47:10.082Z 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 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef --network avalancheFuji
   

   Example output:

   2025-05-15T00:50:43.739Z info: Current token admin: 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T00:50:43.741Z info: Claiming admin of 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef via getCCIPAdmin() for CCIP admin 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T00:50:50.443Z info: Claimed admin of 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef tx: 0x6ee656f97a2dbef9da398076d5b618ab89820735460b9c371c506e74ae5bd1a9
   

2. Claim the admin role on Arbitrum Sepolia:

   npx hardhat claimAdmin --tokenaddress 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 --network arbitrumSepolia
   

   Example output:

   2025-05-15T00:53:32.278Z info: Current token admin: 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T00:53:32.279Z info: Claiming admin of 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 via getCCIPAdmin() for CCIP admin 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T00:53:35.791Z info: Claimed admin of 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 tx: 0x8e2f76e833f4d77095a75af0ad99b0872a76acd7397f5e11f9af4785d494a83a
   

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 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef --network avalancheFuji
   

   Example output:

   2025-05-15T00:57:49.215Z info: Accepted admin role for token 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef tx: 0x8d52265634a13a818524c8d0ada37e1b6e97df72475e8035398ff5b62d770a5e
   

2. Accept the admin role on Arbitrum Sepolia:

   npx hardhat acceptAdminRole --tokenaddress 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 --network arbitrumSepolia
   

   Example output:

   2025-05-15T00:58:53.951Z info: Accepted admin role for token 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 tx: 0x214a3012e6158c896516e553f1c72e0394e6b02e2de38be18ac98d322b7ad4b5
   

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 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef --pooladdress 0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047 --network avalancheFuji
   

   Example output:

   2025-05-15T01:01:22.500Z info: Setting pool for token 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef to 0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047 by 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T01:01:28.430Z info: Pool set for token 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef to 0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047
   

2. Set the pool for Arbitrum Sepolia:

   npx hardhat setPool --tokenaddress 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 --pooladdress 0x74F0842a9A55575e8e36692c356292a812640F67 --network arbitrumSepolia
   

   Example output:

   2025-05-15T01:02:26.011Z info: Setting pool for token 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 to 0x74F0842a9A55575e8e36692c356292a812640F67 by 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T01:02:31.878Z info: Pool set for token 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 to 0x74F0842a9A55575e8e36692c356292a812640F67
   

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 0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047 \
     --remotechain arbitrumSepolia \
     --remotepooladdresses 0x74F0842a9A55575e8e36692c356292a812640F67 \
     --remotetokenaddress 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213 \
     --network avalancheFuji
   

   Example output:

   2025-05-15T01:09:34.681Z info: Applying chain update to pool at address: 0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047
   2025-05-15T01:09:34.681Z info: Remote chain: arbitrumSepolia (3478487238524512106)
   2025-05-15T01:09:34.681Z info: Remote pool addresses: 0x74F0842a9A55575e8e36692c356292a812640F67
   2025-05-15T01:09:34.681Z info: Remote token address: 0x6093e82e2E7b3f3ea4f83dA8Be8b755c4839A213
   2025-05-15T01:09:46.490Z info: Chain update applied successfully
   

2. Configure the pool on Arbitrum Sepolia:

   npx hardhat applyChainUpdates \
     --pooladdress 0x74F0842a9A55575e8e36692c356292a812640F67 \
     --remotechain avalancheFuji \
     --remotetokenaddress 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef \
     --remotepooladdresses 0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047 \
     --network arbitrumSepolia
   

   Example output:

   2025-05-15T01:10:29.863Z info: Applying chain update to pool at address: 0x74F0842a9A55575e8e36692c356292a812640F67
   2025-05-15T01:10:29.863Z info: Remote chain: avalancheFuji (14767482510784806043)
   2025-05-15T01:10:29.864Z info: Remote pool addresses: 0xcC8bb3E03c59603522732B17487D2Cd5a5a3e047
   2025-05-15T01:10:29.864Z info: Remote token address: 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef
   2025-05-15T01:10:33.787Z 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 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef --amount 1000000000000000000000 --network avalancheFuji
   

   Example output:

   2025-05-15T01:12:37.680Z info: Minting 1000000000000000000000 of BnMaem tokens to 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA
   2025-05-15T01:12:45.071Z info: Minted 1000000000000000000000 of BnMaem tokens to 0x8C244f0B2164E6A3BED74ab429B0ebd661Bb14CA - transaction hash: 0x4ce9df23352405141dae8bffdb986b218c96dcdc2041a74bb716f7999ac957d3
   2025-05-15T01:12:45.763Z 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 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef --amount 100000000000000000000 --destinationchain arbitrumSepolia --receiveraddress 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf --network avalancheFuji

Example output:

2025-05-15T01:21:48.987Z info: Estimated fees: 22153771891999418
2025-05-15T01:21:48.990Z info: Approving 100000000000000000000 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef to 0xF694E193200268f9a4868e4Aa017A0118C9a8177
2025-05-15T01:21:58.161Z info: Approving 22153771891999418 LINK to 0xF694E193200268f9a4868e4Aa017A0118C9a8177
2025-05-15T01:22:06.709Z info: Transferring 100000000000000000000 of 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef to 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf on chain arbitrumSepolia with 22153771891999418 of LINK as fees
2025-05-15T01:22:15.308Z info: Transaction hash: 0xf424379cf52b5e6927b5ae2aa2688afa2986c1cc102cf7c2354227da5cc95b18
2025-05-15T01:22:15.322Z warn: Unable to parse the event logs corresponding to the transaction 0xf424379cf52b5e6927b5ae2aa2688afa2986c1cc102cf7c2354227da5cc95b18
2025-05-15T01:22:15.322Z info: Check status of message on https://ccip.chain.link/tx/0xf424379cf52b5e6927b5ae2aa2688afa2986c1cc102cf7c2354227da5cc95b18

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 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef --amount 100000000000000000000 --destinationchain arbitrumSepolia --receiveraddress 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf --fee native --network avalancheFuji

Example output:

2025-05-15T01:24:46.043Z info: Estimated fees: 15594594987586380
2025-05-15T01:24:46.047Z info: Approving 100000000000000000000 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef to 0xF694E193200268f9a4868e4Aa017A0118C9a8177
2025-05-15T01:24:55.052Z info: Transferring 100000000000000000000 of 0xE21b1AA00C6202b606C4F5B9E05B6f475823B8Ef to 0x27d7A69C878F9c8f51f4e53703abCE9bAcd2D9bf on chain arbitrumSepolia with 15594594987586380 of native token as fees
2025-05-15T01:25:03.348Z info: Transaction hash: 0x2f78731a6f41a55c0a2d2f03c6545812f91235c775bec82c21646131dcdcac34
2025-05-15T01:25:03.364Z warn: Unable to parse the event logs corresponding to the transaction 0x2f78731a6f41a55c0a2d2f03c6545812f91235c775bec82c21646131dcdcac34
2025-05-15T01:25:03.364Z info: Check status of message on https://ccip.chain.link/tx/0x2f78731a6f41a55c0a2d2f03c6545812f91235c775bec82c21646131dcdcac34