Smart Router

Overview

Smart Router is a robust trading tool introduced by SUN.io that provides users with a top-notch trading experience by finding them the best prices. Users simply need to select the trading pair and enter the amount they want to trade, and the Smart Router will look for the optimal routing in all the trading pools(SunSwap、SunCurve and PSM) on SUN.io.

The smart router plays an important role in SUN.io:

• Executing trades at the best price: The Smart Router finds the best price for traders by choosing the optimal path to execute trades based on the price difference across markets. This means users get more favorable trade prices at execution to maximize returns.

• Enhancing liquidity: The Smart Router utilizes the liquidity of different markets to provide better depth and liquidity for traders. By executing trades across multiple liquidity pools, it reduces slippage and market shocks, thus offering an enhanced trading experience.

• Improving liquidity utilization: The Smart Router helps improve the utilization of liquidity. By channeling liquidity from highly liquid markets to less liquid ones, it helps improve the overall utilization of liquidity and enables the completion of more trades.

Mechanism

Smart Router Architecture Diagram SUN.io's Smart Router algorithm service retrieves data from SunSwap V1, SunSwap V2, SunSwap V3, PSM, and SunCurve by utilizing the contract image built on the server. It sorts trade paths by the amount of the token users can obtain and displays the top three as options for users. The contract of the Smart Router is a nested contract through which the liquidity pools on SunSwap V1, SunSwap V2, SunSwap V3, PSM, and SunCurve can be called to complete trades.

Build

Install tronbox

npm install tronbox
npm run build

Build router

• change tronbox.js options

version: '0.6.8'

• Compile

tronbox compile

Deploy

Set Private Key

export PRIVATE_KEY_NILE='Your private key'

Deploy

tronbox migrate --network nile --f 1 --to 2

How to Use

User can invoke the swapExactInput method of the smart contract to trigger the transaction. The smart router will handle the transaction data internally and complete the trade.

Build the transaction

1.swapExactInput Function

Description

The swapExactInput function is the unified entrance for swaps.

Function Signature:

function swapExactInput(
        address[] calldata path,
        string[] calldata poolVersion,
        uint256[] calldata versionLen,
        uint24[] calldata fees,
        SwapData calldata data
    ) external nonReentrant payable returns (uint256[] memory amountsOut)

struct SwapData {
        uint256 amountIn;
        uint256 amountOutMin;
        address to;
        uint256 deadline;
    }

Parameters:

• path: The token address list for swap to.
• poolVersion: The version list for pool‘s version for pathed token.
• versionLen: The length list for pool’s length by version.
• fees: The fees list for pool’s fees, just support the SUNSWAP V3 pools
• data: The swap info ,Use SwapData Structure ,obtain token amountIn, min amountOut expect amountOutMin ,receiver to and deadline

Fullfill the Parameters

If user use 100000 USDT to swap USDD token, the parameteres should be:

Name	Value	Description
path	[USDT address,USDD address]	path of tokens
poolVersion	['usdt20psm']	poolVersion can be v1,V2,V3,usdt20psm,usdd202pool，2pooltusdusdt,usdc2pooltusdusdt,usdd2pooltusdusdt,usdj2pooltusdusdt, oldusdcpool,old3pool
versionLen	['2']	array of counts of token numbers in poolVersions, eg: if path = [A,B,C,D],poolVersion = ['v2','v2','v3'],that means A->B use 'V2', B->C use 'V2',C->D use 'V3',so the versionLen = ['3','1']. The number of first poolversion count must +1
fees	[0,0]	poolFees used to distinguish V3 pools; all other pools are set to 0.
data	['100000000000',amountOut *(1 - flapPiont),receiver,deadline]	SwapData

Trigger the transaction

Example Call:

const tronWeb = require('tronweb');
const contractAddress = 'TCFNp179Lg46D16zKoumd4Poa2WFFdtqYj';

const amountOutMin = '99000000000000000000000'; // Example minimum amount of tokens to receive ,1% flap point
const pathUSDT2USDD =       ["TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t",
        "TXDk8mbtRbXeYuMNS83CfKPaYYT8XWv9Hz"]; // Example path
const poolVersion = ["usdt20psm"];
const versionLen = ["2"];
const fees = [0,0];
const amountIn = '100000000000'
const to = 'TYourAddressHere';
const deadline = Math.floor(Date.now() / 1000) + 60 * 20; // 20 minutes from the current Unix time
const swapdata = [amountIn,amountOutMin,to,deadline];

const swapExactInput = async () => {
    const contract = await tronWeb.contract(abi, contractAddress);
    await contract.swapExactInput(
        path, 
        poolVersion, 
        versionLen, 
        fees,
        swapdata
    ).send();
};

🔗 Related Resources

• Official Website: SUN.io
• Blockchain Explorer: TRONSCAN
• Developer Documentation: SUN.io Docs