bsc-dex-helper

BSC DEX helpers for trading bots: PancakeSwap V2 router/factory addresses, getAmountsOut/getAmountsIn quotes, and slippage utilities.

Install

npm install bsc-dex-helper

Use with a BSC provider (e.g. bsc-provider-helper):

npm install bsc-provider-helper bsc-dex-helper

Usage

const { getProvider } = require('bsc-provider-helper');
const {
  getRouterV2,
  getWbnb,
  getAmountsOut,
  getAmountsIn,
  quoteOut,
  applySlippageBps,
} = require('bsc-dex-helper');

const provider = getProvider();
const WBNB = getWbnb(56);
const BUSD = '0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56'; // BSC mainnet example

// Quote: 1 BNB -> expected BUSD out
const oneBnb = 10n ** 18n;
const amounts = await getAmountsOut(provider, oneBnb, [WBNB, BUSD]);
const expectedOut = amounts[amounts.length - 1];

// Min amount out with 0.5% slippage (50 bps)
const minOut = applySlippageBps(expectedOut, 50);

// Required amount in for 1000 BUSD out
const wantOut = 1000n * 10n ** 18n;
const requiredIn = await quoteIn(provider, wantOut, WBNB, BUSD);

Subpath imports

const { getRouterV2, getWbnb } = require('bsc-dex-helper/addresses');
const { getAmountsOut, quoteOut } = require('bsc-dex-helper/quotes');
const { applySlippageBps, addSlippageBps } = require('bsc-dex-helper/slippage');

API

Addresses (lib/addresses.js)

| Method / Constant | Description | |------------------|-------------| | getRouterV2(chainId?) | PancakeSwap V2 router address (BSC 56 / testnet 97) | | getFactoryV2(chainId?) | PancakeSwap V2 factory address | | getWbnb(chainId?) | WBNB token address | | ROUTER_V2, FACTORY_V2, WBNB_MAINNET, WBNB_TESTNET | Raw address maps |

Quotes (lib/quotes.js)

| Method | Description | |--------|-------------| | getAmountsOut(provider, amountIn, path, chainId?) | Router getAmountsOut; returns array of amounts (last = expected out) | | getAmountsIn(provider, amountOut, path, chainId?) | Router getAmountsIn; returns array (first = required in) | | quoteOut(provider, amountIn, tokenIn, tokenOut, chainId?) | Single-hop expected amountOut | | quoteIn(provider, amountOut, tokenIn, tokenOut, chainId?) | Single-hop required amountIn |

Slippage (lib/slippage.js)

| Method | Description | |--------|-------------| | applySlippageBps(amount, slippageBps) | Min amount after slippage (e.g. 50 bps = 0.5%) | | applySlippagePercent(amount, slippagePercent) | Same using percentage (e.g. 0.5) | | addSlippageBps(amount, slippageBps) | Max amount (e.g. for amountInMax) |

Dependencies

• ethers ^6.x

Optional peer: bsc-provider-helper for getProvider() when using this in a bot.

License

MIT