Umee ERC20 Token

The new Umee is a Solidity smart contract designed to handle the transition of UMEE tokens from the deprecated Gravity Bridge to the new Axelar-supported token system. It facilitates the swapping of old UMEE tokens for new ones. This will then use Axelar to bridge between umee <> Ethereum and other future chains

Features

• Swap deprecated Gravity Bridge UMEE tokens for new Axelar-supported UMEE tokens.
• Custom token decimals for display purposes (6 decimals).
• Reentrancy protection using OpenZeppelin's ReentrancyGuard.
• Implements the ERC20 Permit extension for gasless approvals

Functions

• swap(uint256 amount): Allows users to swap their deprecated Gravity Bridge UMEE tokens for new Axelar-supported UMEE tokens by providing the amount they want to swap.
• decimals(): Returns the number of decimals used for display purposes (6 decimals).

Events

• SwapGB(address indexed user, uint256 amount): Emitted when a token swap occurs, providing the address of the user who initiated the swap and the amount of tokens swapped.

Custom Errors

• InvalidAmount(): Custom error thrown when the provided amount is less than or equal to zero.

Create a .env with ETHERSCAN_API_KEY, a PRIVATE_KEY and an RPC (ETHEREUM_RPC for Ethereum) then run the following commands. For the network flag choose from a network in the hardhat config or add a new network

Test

npm i

npx hardhat node //start local fork of mainnet

npx hardhat test

Live Contract:

Goerli

New Umee: https://goerli.etherscan.io/address/0x1589F1bA7baEfffc72ed2d80a59441f1B5Ec929C#code Test GB Umee: https://goerli.etherscan.io/address/0x5d28233feb3DdE64961d700186d0e7E1CBA4ac52#code

Deployment

npm i

npx hardhat run scripts/deploy.ts --network mainnet

Dependencies

• OpenZeppelin's ERC20, IERC20, and ReentrancyGuard contracts.