# Best Practice ### Step 1: Get Token Info You can call the get Token List API to get all the available tokens we have on the blockchain you choose. * Method: Get * URL: * Parameters:
parametertypeexampledescription
chainstringbsceth, bsc, polygon, avax, arbitrum, fantom, xdai, moonriver, aurora, cronos, harmony, solana, sifchain, osmosis, optimism, ont, tron, okex, zksync, linea, scroll
**Your request will look like this:** ``` async tokenList() {   const { data } = axios.get('https://api.0xgen.io/v1/bsc/tokenList'); } ``` **And your response will look like this:** 
{  "code": 200,
    "data": [
        {
            "id": 2048,
            "code": "ezeth",
            "name": "Renzo Restaked ETH",
            "address": "0x2416092f143378750bb29b79eD961ab195CcEea5",
            "decimals": 18,
            "symbol": "ezETH",
            "icon": "https://s3.0xgen.io/logos/1720409237571_35144943543615725.png",
            "chain": "bsc",
            "createtime": "2024-07-08T03:27:21.000Z",
            "hot": null,
            "sort": "2024-07-08T03:27:21.000Z",
            "chainId": null,
            "usd": null
        },...]
}
**Then you pick up the token you choose in the specific chain which is included. You need to save the token information you need for further operations** ### Step 2: Quote **You can obtain quotes from different platforms.** * Method: Get * URL: * Parameters:
parametertypeexampledescription
chainstringbsceth, bsc, polygon, avax, arbitrum, fantom, xdai, moonriver, aurora, cronos, harmony, solana, sifchain, osmosis, optimism, ont, tron, okex, zksync, linea, scroll
inTokenAddressstring0x783C08b5F26E3daf8C4681F3bf49844e425b6393token address
outTokenAddressstring0xD81D45E7635400dDD9c028839e9a9eF479006B28out token address
amountstring5token amount(without decimals)
gasPricestring1without decimals
**Your request will be like this** ```javascript   let params = {       inTokenAddress: '0x9029FdFAe9A03135846381c7cE16595C3554e10A',       outTokenAddress: '0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE',       amount: 5,       gasPrice: 1,       };   async quote(){     const { data } = await axios.get('https://api.0xgen.io/v1/bsc/quote', {params})   } ``` **And your response will look like this:** ```javascript {   "code": 200,   "data": {       "dexes": [           {               "name": "openOcean",               "amount": "1614773503060146858429"           },           {               "name": "1inch",               "amount": "1614222924617714762008"           }       ],       "maxOutAmount": "1614773503060146858429",       "minOutAmount": "1614222924617714762008",       "inToken": {           "symbol": "BNB",           "name": "Binance Coin",           "address": "0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE",           "decimals": 18       },       "outToken": {           "symbol": "1INCH",           "name": "1INCH Token",           "address": "0x111111111117dc0aa78b770fa6a738034120c302",           "decimals": 18       },       "inAmount": "5000000000000000000"   } } ``` ### Step 3: Obtain on-chain transaction data. **You can obtain the on-chain transaction data from a specified platform.** * Method: Get * URL: * Parameters: | parameter | type | example | description | | --------------- | ------- | ------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | | chain | string | bsc | eth, bsc, polygon, avax, arbitrum, fantom, xdai, moonriver, aurora, cronos, harmony, solana, sifchain, osmosis, optimism, ont, tron, okex, zksync, linea, scroll | | dex | string | openOcean | openOcean, 1inch, paraSwap, matcha, jupiter, 1sol | | inTokenAddress | string | 0x783C08b5F26E3daf8C4681F3bf49844e425b6393 | token address | | outTokenAddress | string | 0xD81D45E7635400dDD9c028839e9a9eF479006B28 | out token address | | amount | string | 5 | token amount(without decimals) | | gasPrice | string | 5 | without decimals | | slippage | number | 1 | 1 equals 1%, 1%-100% | | account | string | | user's address | | disableEstimate | boolean | true | true/false(check balance and allowance) | | referrer | string? | 0x0000000000000000000000000000000000000000 | Please contact us for a unique referrer parameter | **For example, you want to use openocean to obtain the on-chain transaction data;** ```javascript {   let params = {       inTokenAddress: '0x9029FdFAe9A03135846381c7cE16595C3554e10A',       outTokenAddress: '0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE',       amount: 5,       gasPrice: 1,       slippage:100,       account: ''// wallet address       };   const res = await axios.get('https://api.0xgen.io/v1/bsc/openOcean/swap_quote', {params}) } ``` **response:** If you call it right, you will get a result like this: ```javascript {   "code": 200,   "data": {       "inToken": {           "symbol": "BNB",           "name": "Binance Coin",           "address": "0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE",           "decimals": 18       },       "outToken": {           "symbol": "USDT",           "name": "Binance-Peg USD (T)",           "decimals": 18,           "address": "0x55d398326f99059ff775485246999027b3197955"       },       "inAmount": "5000000000000000",       "outAmount": "1533988843342961506",       "estimatedGas": "198245",       "minOutAmount": "1518648954909531891",       "from": "0x929B44e589AC4dD99c0282614e9a844Ea9483C69",       "to": "0x6352a56caadC4F1E25CD6c75970Fa768A3304e64",       "value": "5000000000000000",       "gasPrice": "5000000000",       "data": ""   }   } ``` #### sendTransaction Here is a case for you to make a transaction on BNB Chain. ```javascript import { ethers } from "ethers"; import axios from "axios"; async function swap() {   const account = ''; // wallet address;   const private_key = ''; //private key;   const provider = new ethers.providers.JsonRpcProvider('');   const wallet = new ethers.Wallet(private_key, provider);   let params = {       inTokenAddress: '0x9029FdFAe9A03135846381c7cE16595C3554e10A',       outTokenAddress: '0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE',       amount: 5,       gasPrice: 1,       slippage: 100,       account// wallet address   };   const res = await axios.get("https://api.0xgen.io/v1/bsc/openOcean/swap_quote", { params });   if (res) { ​       const { estimatedGas, data, gasPrice } = res.data.data;       const swapParams = {           from: '', // wallet address           to: '0x6352a56caadc4f1e25cd6c75970fa768a3304e64', //Please use the contract from the contract page           gas: estimatedGas,           gasPrice: gasPrice,           data       }; ​       if (isNativeToken(params.inTokenAddress.toLowerCase())) {           swapParams.value = ethers.BigNumber.from(res.data.value);       } ​       const { hash } = await wallet.sendTransaction(swapParams)   } else {       return   } } ```