Dex development details

This page provides general information about the used contract and required files around the contract. All contract source codes can be found under the src folder.

Contracts overview

The following are the main contract features:

• Fork of Uniswap V3 for Polygon.

• Tiered transaction fees.

• Allow users add arbitrary coin/ERC20 Pools.

• Concentrated liquidity model

  • Default range of +/-20% of current price
  • Option for custom ranges (for a fee)

• Yield and dividend features:

  • Auto-compounds yields into the pool
  • Provides harvestable rewards for LPs (native coin or token e.g. HKD)

Unit tests

The contracts are covered by unit tests. Both happy paths and unhappy paths should be sufficiently covered.

You can run unit tests with Hardhat: npx hardhat test.

Development

To start development on the project, you should do (at least) the following:

1. Install packages: npm i

2. Compile contracts: npx hardhat compile

3. Run unit tests: npx hardhat test

Deployment

A sample deployment script has been created. It deploys all the contracts and also verifies them in Etherscan. You can run the script by following these steps:

1. Set up environment variables in a file called .env. There is an example of the settings in .env.example.

2. Run script with npx hardhat run scripts/deploy.ts --network [network]

   • base-amoy: This is for Polygon test Network
   • base-polygon: This is for Poygon main Network
   • sepolia: This is for Ethereum test Network
   • base-ethereum: This is for Ethereum main Network
   • base-binance: This is for Binance main Network

Verification

• Create Polygon scan API KEY(update .env file) and run the script.

  npx hardhat verify --network [network] deployed_address args

• here is example

  npx hardhat verify --network base-amoy 0x1A8F35390151042886dDf2221886AAc25E689b3F

Frontend Collaborations

• Reorder of the Token A and Token B addresses is required:

  if (token0.address.toUpperCase() > token1.address.toUpperCase()) {
    let temp = token0;
    token0 = token1;
    token1 = temp;
  }

• Customized price range should be provided as starting tick point and ending tick point

Latest Deployment

The latest test deployment to Amoy network is following

• Dex Factory

• Dex QuoterFact

• Dex ManagerFact

Usage

Description for the usage of Dex contract.

• Creat a Pool

  • createPool is a function for creating a pool
  • there are 4 input parameters
    • tokenA: first token address like 0x6D502C7Ec05e89aDDBF2B0Cf2Eea28a1534Dd362
    • tokenB: second token address like 0xF8bb0a8fd3A54b5B35Cc9E75214eD851C923E9E5
    • fee: this is representing fee choice of swaping. there are 4 tired fee options: 100 (0.01%), 500 (0.05%), 3000 (0.3%), 10000 (1%)
    • currentPrice: this is the price ratio between tokenA and tokenB. this value is calculated like

      currentPrice = tokenB.price / tokenA.price * 10 ^ 10
      

      Warning: becareful for the order of tokenA and tokenB. Refer this: Jump to Frontend Collaborations

• Add Liquidity

  • mint function is for Adding Liquidity.
  • there are 9 parameters are required.
    • tokenA is for the ordered first token address.
    • tokenB is for the ordered second token address.
    • fee is representing pool fee amount.
    • lowerTick is the starting tick point.
    • upperTick is the eding tick point.
    • amount0Desired this is the desired tokenA amount
    • aomount1Desired this is the desired tokenB amount
    • amount0Min this is minimum amount for tokenA
    • amount1Min thi is minimum amount for tokenB

  Warning:

  • tokenA, tokenB and fee are used to indicate the pool contract.
  • default lowerTick and upperTick are found from getStandardSlot0()

• Swap

  • swapSingle is for swapping tokens for existing token pairs.
  • there are 4 input parameters
    • tokenIn: this is for token address that will be swapped.
    • tokenOut : this is token addresss that will get after swapping.
    • fee : this is swaping fee. this would be used to indicate the pool together with tokenIn and tokenOut

• Remove Liquidity

  • burn is the function for removing liquidity.
  • there are 6 input parameters
    • tokenA
    • tokenB
    • fee
    • lowerTick
    • upperTick
    • liquidity this is the amount for withdrawal of liquidity

  Warning:

  • lowerTick and upperTick should be same as adding liquidity unless it would fail.
  • if the liquidity is above the actual amount of LP's liquidity amount, it will withdraw his total amount.

• Yield Farming

  • collect is the function for yielding accumulated liquid revenue.
  • there are 8 input parameters
    • tokenA
    • tokenB
    • fee
    • recipient this is wallet address for receiving the liquidity revenue.
    • lowerTick
    • upperTick
    • amount0Desired
    • amount1Desired

• Yield Owner Fee

  • collectOwnerFee is the function for collecting accumulated Admin fee.
  • this is similar to Yield Farmining

Precaution

• before starting the transactions like mint and swap you need to make sure that you approved allowance to the contract for the amount you want to transfer.