AimBridge Smart Contracts

AimBridge is a proof of concept for a EVM token-bridge developed that uses OpenZeppelin Defender in order to manage the transactions between two networks.

Smart Contracts

The project is made up of a total of three smart contracts:

• WERC20: an ERC20 contract that allows for creation and minting of new tokens
• Wrapper Tokan Factory: a factory smart contract that manages all of the created ERC20 tokens as well as hold some functionality.
• Bridge : Holds the main functionlity for transfering tokens between netowks by using an implementation of the Factory contract.

WERC20

The WERC20 contract etends OpenZeppelin ERC20 contracts directly and does not have any extra implementation on top of that.

Factory

The Factory contract is a way create and manage WERC20 tokens, it has methods to create , mint, burn as well as get the balance of a user.

These methods were created in order to add an extra layer of validation and a different way to access the tokens.

Methods

createWERC20

Method for creating a new ERC20 token.

Parameter	Type	Description
name	string	The full length name of the token ex: AimBridge Token
symbol	string	The symbol for the token ex: AIM

getWERC20

Method for getting an address of an ERC20 token.

Parameter	Type	Description
symbol	string	The symbol for the token ex: AIM

mint

Method for minting a certian amount of a token.

Parameter	Type	Description
symbol	string	The symbol for the token ex: AIM
to	address	The address of the recipient of the token
amount	uint256	The amount of tokens to be minted

BalanceOf

Method for getting the balance of a user on a certain ERC20.

Parameter	Type	Description
symbol	string	The symbol for the token ex: AIM
account	address	The address of the holder of the token

myBalanceOf

Method for getting the caller's balance for a certain ERC20.

Parameter	Type	Description
symbol	string	The symbol for the token ex: AIM

burn

Method for burning a certain amount of token.

Parameter	Type	Description
tokenAddress	address	The address of a token to be burned
from	address	The address of the holder of tokens to be burned
amount	uint256	Amount of tokens to be burned

burnWithPermit

Method for burning a certain amount of token with permits.

Parameter	Type	Description
tokenAddress	address	The address of a token to be burned
from	address	The address of the holder of tokens to be burned
amount	uint256	Amount of tokens to be burned
deadline	uint256	Deadline for the permit
v	uint8	Signature element
r	byte32	Signature element
s	byte32	Signature element

Bridge

The bridge contract works in connection with the Factory contract to provide the functionality for transfering the token between networks

Methods

initiateTransfer

This method is responsible for starting the transfer and locking the native token onto the source network bridge contract.

Parameter	Type	Description
user	address	The address of the user that initiated the transfer
tokenAddress	address	The address of the native token token that is being bridged
targetChainId	uint256	The ID of the network the token is being bridged to, ex: Goerli = 5
amount	uint256	The amount of the token being bridged

initiateTransferWithPermit

This method is responsible for starting the transfer and locking the native token onto the source network bridge contract but implements permit to avoid using the approval method.

Parameter	Type	Description
user	address	The address of the user that initiated the transfer
tokenAddress	address	The address of the native token token that is being bridged
targetChainId	uint256	The ID of the network the token is being bridged to, ex: Goerli = 5
amount	uint256	The amount of the token being bridged
deadline	uint256	Deadline for the permit
v	uint8	Signature element
r	byte32	Signature element
s	byte32	Signature element

mintToken

This method is called on the target network after the transfer is initiated in order to mint an equivalent amount of token on the target network.

Parameter	Type	Description
symbol	string	The symbol for the token ex: AIM
tokenName	string	The full length name of the token ex: AimBridge Token
to	address	The address of the recipient of the newly minted token
tokenAddress	address	The address of the native token token that is being bridged
amount	uint256	The amount of the token being bridged

burnWrappedToken

This method burns the user's wrapped tokens, in preperation for releasing the native token on the original network.

Parameter	Type	Description
symbol	string	The symbol for the token ex: AIM
amount	uint256	The amount of the token being bridged
user	address	The address of the user that is burning the tokens

burnWrappedTokenWithPermit

This method burns the user's wrapped tokens, in preperation for releasing the native token on the original network but with Permits.

Parameter	Type	Description
symbol	string	The symbol for the token ex: AIM
amount	uint256	The amount of the token being bridged
user	address	The address of the user that is burning the tokens
deadline	uint256	Deadline for the permit
v	uint8	Signature element
r	byte32	Signature element
s	byte32	Signature element

unWrapToken

This method releases native tokens on the original network

Parameter	Type	Description
to	address	The address of the recipient of the native token
nativeTokenAddress	address	The address of the native token
amount	uint256	The amount of the token being bridged

setFee

A method for the admin to change the bridge fee. defaults to 0.001 ETH.

Parameter	Type	Description
fee	uint256	The new fee amount for the bridge.

Environment Variables

# Wallet Private Key
PRIVATE_KEY=

# Mumbai RPC URL 
MUMBAI_RPC_URL=

#Polyscan API key
POLYSCAN=EWTP38N28M3XSPESIIAW293Y2DCGTXCZWH

#Alchemy API key
ALCHEMY_API_KEY=

#Alchemy Goerli http url
ALCHEMY_GOERELI_KEY=

Run Locally

Clone the project

git clone https://github.com/aimensahnoun/EVM-Bridge-hh

Go to the project directory

cd my-project

Install dependencies

npm install

  

#or

  

yarn install

Running Tests

To run tests, run the following command

hardhat test

To coverage tests, run the following command

hardhat coverage

Deployment

To deploy this project run

hh run --network NETWORK scripts/deploy.ts

📦 
├─ .gitignore
├─ README.md
├─ contracts
│  ├─ Bridge.sol
│  ├─ WERC20.sol
│  └─ WERC20Factory.sol
├─ hardhat.config.ts
├─ package-lock.json
├─ package.json
├─ scripts
│  ├─ autotasker-script.js
│  ├─ deploy.ts
│  ├─ factory-test-source.ts
│  └─ factory-test-target.ts
├─ test
│  ├─ Bridge.ts
│  ├─ WERC20.ts
│  └─ WERC20Factory.ts
├─ tsconfig.json
└─ yarn.lock