Native Token Transfers (NTT) EVM Development
Deploy Your Token and Ensure Compatibility
If you still need to do so, deploy the token contract to the destination or spoke chains.
Tokens integrated with NttManager
in burning
mode require the following two functions to be present:
burn(uint256 amount)
mint(address account, uint256 amount)
These functions aren't part of the standard ERC-20 interface. The INttToken
interface documents the required functions and convenience methods, errors, and events.
View the complete INttToken
Interface`
// SPDX-License-Identifier: Apache 2
pragma solidity >=0.8.8 <0.9.0;
interface INttToken {
/// @notice Error when the caller is not the minter.
/// @dev Selector 0x5fb5729e.
/// @param caller The caller of the function.
error CallerNotMinter(address caller);
/// @notice Error when the minter is the zero address.
/// @dev Selector 0x04a208c7.
error InvalidMinterZeroAddress();
/// @notice Error when insufficient balance to burn the amount.
/// @dev Selector 0xcf479181.
/// @param balance The balance of the account.
/// @param amount The amount to burn.
error InsufficientBalance(uint256 balance, uint256 amount);
/// @notice The minter has been changed.
/// @dev Topic0
/// 0x0b5e7be615a67a819aff3f47c967d1535cead1b98db60fafdcbf22dcaa8fa5a9.
/// @param newMinter The new minter.
event NewMinter(address previousMinter, address newMinter);
// NOTE: the `mint` method is not present in the standard ERC20 interface.
function mint(address account, uint256 amount) external;
// NOTE: the `setMinter` method is not present in the standard ERC20 interface.
function setMinter(address newMinter) external;
// NOTE: NttTokens in `burn` mode require the `burn` method to be present.
// This method is not present in the standard ERC20 interface, but is
// found in the `ERC20Burnable` interface.
function burn(uint256 amount) external;
}
Later, you set mint authority to the corresponding NttManager
contract. You can also follow the scripts in the example NTT token repository to deploy a token contract.
Deploy NTT
Create a new NTT project:
Initialize a new deployment.json
file, specifying the network:
Ensure you have set up your environment correctly:
Add each chain you'll be deploying to. The following example demonstrates configuring NTT in burn-and-mint mode on Ethereum Sepolia and Arbitrum Sepolia:
# Set scanner API Keys as environment variables
export SEPOLIA_SCAN_API_KEY=INSERT_ETHERSCAN_SEPOLIA_API_KEY
export ARBITRUMSEPOLIA_SCAN_API_KEY=INSERT_ARBISCAN_SEPOLIA_API_KEY
# Add each chain
# The contracts will be automatically verified using the scanner API keys above
ntt add-chain Sepolia --latest --mode burning --token INSERT_YOUR_TOKEN_ADDRESS
ntt add-chain ArbitrumSepolia --latest --mode burning --token INSERT_YOUR_TOKEN_ADDRESS
While not recommended, you can pass the -skip-verify
flag to the ntt add-chain
command if you want to skip contract verification.
The ntt add-chain
command takes the following parameters:
- Name of each chain
- Version of NTT to deploy (use
--latest
for the latest contract versions) - Mode (either
burning
orlocking
) - Your token contract address
The NTT CLI prints detailed logs and transaction hashes, so you can see exactly what's happening under the hood.
Configure NTT
The NTT CLI takes inspiration from git. You can run:
ntt status
- checks whether yourdeployment.json
file is consistent with what is on-chain-
ntt pull
- syncs yourdeployment.json
file with the on-chain configuration and set up rate limits with the appropriate number of decimals, depending on the specific chain. For example:For Solana, the limits are set with 9 decimal places:
For Sepolia (Ethereum Testnet), the limits are set with 18 decimal places:
This initial configuration ensures that the rate limits are correctly represented for each chain's token precision
-
ntt push
- syncs the on-chain configuration with local changes made to yourdeployment.json
file
After you deploy the NTT contracts, ensure that the deployment is properly configured and your local representation is consistent with the actual on-chain state by running ntt status
and following the instructions shown on the screen.
Set Token Minter to NTT Manager
The final step in the deployment process is to set the NTT Manager as a minter of your token on all chains you have deployed to in burning
mode. When performing a hub-and-spoke deployment, it is only necessary to set the NTT Manager as a minter of the token on each spoke chain.
- If you followed the
INttToken
interface, you can execute thesetMinter(address newMinter)
function - If you have a custom process to manage token minters, you should now follow that process to add the corresponding NTT Manager as a minter
By default, NTT transfers to EVM blockchains support automatic relaying via the Wormhole relayer, which doesn't require the user to perform a transaction on the destination chain to complete the transfer.