Interchain Token

An interchain ERC20 token contract
****ERC20 Token **** app is an interchain ERC20 token contract using the App framework.
The hyperlane-token repo shows an example Interchain Token, an ERC20 that can travel between any Hyperlane chain, also called a HypERC20.
The changes to the vanilla OpenZeppelin ERC20 contract are minimal. It has a transferRemote() function that burns the specified amount of tokens on the sending chain and mints the equivalent amount on the receiving chain.


Its contract implements a transferRemote method which burns tokens and dispatches corresponding messages.
* @notice Transfers `_amount` of tokens from `msg.sender` to `_recipient` on the `_destination` chain.
* @dev Burns `_amount` of tokens from `msg.sender` on the origin chain and dispatches
* message to the `destination` chain to mint `_amount` of tokens to `recipient`.
* @param _destination The identifier of the destination chain.
* @param _recipient The address of the recipient on the destination chain.
* @param _amount The amount of tokens to be sent to the remote recipient.
function transferRemote(
uint32 _destination,
address _recipient,
uint256 _amount
) external payable {
_burn(msg.sender, _amount);
Message.format(_recipient, _amount),
It also requires a _handle method which mints tokens upon receiving messages.
* @dev Mints tokens to recipient when router receives transfer message.
* @param _origin The identifier of the origin chain.
* @param _message The encoded remote transfer message containing the recipient address and amount.
function _handle(
uint32 _origin,
bytes memory _message
) internal override {
(address recipient, uint256 amount) = abi.decode(
(address, uint256)
_mint(recipient, amount);