Swap Integration

Swap Integration

Integrate PancakeSwap swaps into frontends, backends, and smart contracts.

Quick Decision Guide

| Building... | Use This Method | | ------------------------------------------ | ------------------------------------------------------------------------------ | | Quick quote or prototype | PancakeSwap Routing API (Method 1) | | Frontend with React/Next.js | Smart Router SDK + Universal Router (Method 2) | | Backend script or trading bot | Smart Router SDK + Universal Router (Method 2) | | Simple V2 swap, smart contract | Direct V2 Router contract calls (Method 3) | | Need exact Universal Router encoding | Universal Router SDK directly (Method 2) | | Swap through Infinity (v4) CL or Bin pools | Routing API (Method 1) or Smart Router SDK with Infinity pool types (Method 2) |

Protocol Types

| Protocol | Description | Fee Tiers (bps) | Chains | | ------------ | ------------------------------------------------------------------------------------------------ | ----------------------- | ------------- | | V2 | Classic AMM (xy=k), constant product formula | 25 (0.25%) | BSC only | | V3 | Concentrated liquidity (Uniswap V3-compatible) | 1, 5, 25, 100 (0.01–1%) | All chains | | StableSwap | Low-slippage for correlated/pegged assets | 1, 4 (0.01–0.04%) | BSC only | | Infinity CL | Concentrated liquidity in the v4 singleton PoolManager; supports hooks for custom logic | Same tiers as V3 | BSC, Base | | Infinity Bin | Fixed-price-bin liquidity (similar to Trader Joe v2); tight ranges, predictable bin-level prices | Configurable | BSC, Base | | Mixed | Split route across any combination of the above protocols | N/A (composite) | BSC primarily |

Supported Chains

| Chain | Chain ID | V2 | V3 | StableSwap | Infinity CL | Infinity Bin | RPC | | ----------------------- | -------- | --- | --- | ---------- | ----------- | ------------ | ------------------------------------------------------------------------ | | BNB Smart Chain | 56 | ✅ | ✅ | ✅ | ✅ | ✅ | https://bsc-dataseed1.binance.org | | BNB Smart Chain Testnet | 97 | ✅ | ❌ | ❌ | ❌ | ❌ | https://bsc-testnet-rpc.publicnode.com or https://bsc-testnet.drpc.org | | Ethereum | 1 | ❌ | ✅ | ❌ | ❌ | ❌ | https://cloudflare-eth.com | | Arbitrum One | 42161 | ❌ | ✅ | ❌ | ❌ | ❌ | https://arb1.arbitrum.io/rpc | | Base | 8453 | ❌ | ✅ | ❌ | ✅ | ✅ | https://mainnet.base.org | | Polygon | 137 | ❌ | ✅ | ❌ | ❌ | ❌ | https://polygon-rpc.com | | zkSync Era | 324 | ❌ | ✅ | ❌ | ❌ | ❌ | https://mainnet.era.zksync.io | | Linea | 59144 | ❌ | ✅ | ❌ | ❌ | ❌ | https://rpc.linea.build | | opBNB | 204 | ❌ | ✅ | ❌ | ❌ | ❌ | https://opbnb-mainnet-rpc.bnbchain.org |

> For testing: Use BSC Testnet (chain ID 97). Get free testnet BNB from . > The Smart Router SDK does not index testnet pools — use Method 3 (Direct V2 Router) on testnet.

Key Token Addresses

BSC Mainnet (Chain ID: 56)

| Token | Address | | ----- | -------------------------------------------- | | WBNB | 0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c | | BUSD | 0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56 | | USDT | 0x55d398326f99059fF775485246999027B3197955 | | USDC | 0x8AC76a51cc950d9822D68b83fE1Ad97B32Cd580d | | CAKE | 0x0E09FaBB73Bd3Ade0a17ECC321fD13a19e81cE82 | | ETH | 0x2170Ed0880ac9A755fd29B2688956BD959F933F8 | | BTCB | 0x7130d2A12B9BCbFAe4f2634d864A1Ee1Ce3Ead9c |

BSC Testnet (Chain ID: 97)

| Token | Address | Notes | | -------- | -------------------------------------------- | ------------------- | | WBNB | 0xae13d989daC2f0dEbFf460aC112a837C89BAa7cd | | | CAKE | 0xFa60D973f7642b748046464E165A65B7323b0C73 | | | BUSD | 0xeD24FC36d5Ee211Ea25A80239Fb8C4Cfd80f12Ee | | | V2Router | 0x9Ac64Cc6e4415144C455BD8E4837Fea55603e5c3 | PancakeSwap testnet |

Universal Router Addresses

| Chain | Chain ID | Universal Router Address | | --------------- | -------- | -------------------------------------------- | | BNB Smart Chain | 56 | 0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD | | Ethereum | 1 | 0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD | | Arbitrum | 42161 | 0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD | | Base | 8453 | 0x198EF79F1F515F02dFE9e3115eD9fC07183f02fC | | Polygon | 137 | 0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD | | zkSync Era | 324 | 0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD | | Linea | 59144 | 0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD | | opBNB | 204 | 0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD |

---

Method 1: PancakeSwap Routing API (Simplest)

Best for: Quick quotes, prototypes, and situations where you don't want to manage on-chain pool data yourself. No SDK installation required.

Base URL: https://router.pancakeswap.finance/v0/quote

Get a Quote

# Exact input: 1 BNB → CAKE on BSC
curl -s "https://router.pancakeswap.finance/v0/quote?\
tokenInAddress=BNB\
&tokenInChainId=56\
&tokenOutAddress=0x0E09FaBB73Bd3Ade0a17ECC321fD13a19e81cE82\
&tokenOutChainId=56\
&amount=1000000000000000000\
&type=exactIn\
&maxHops=3\
&maxSplits=4" | jq '{
  amountOut: .trade.outputAmount,
  priceImpact: .trade.priceImpact,
  route: [.trade.routes[].type]
}'

API Parameters

| Parameter | Type | Description | | ----------------- | ------ | --------------------------------------------------- | | tokenInAddress | string | Input token address or "BNB" / "ETH" for native | | tokenInChainId | number | Input chain ID | | tokenOutAddress | string | Output token address | | tokenOutChainId | number | Output chain ID | | amount | string | Amount in raw units (wei for 18-decimal tokens) | | type | string | "exactIn" or "exactOut" | | maxHops | number | Max hops per route (default: 3) | | maxSplits | number | Max route splits (default: 4) |

> Infinity (v4) support: The Routing API automatically considers Infinity CL and Infinity Bin pools on BSC and Base alongside V2/V3/StableSwap. No extra parameters are needed — the router selects the best route across all pool types.

TypeScript Fetch Example

interface PancakeRouteQuote {
  trade: {
    inputAmount: string
    outputAmount: string
    priceImpact: string
    routes: Array
    blockNumber: number
  }
}

async function getQuote(params: {
  tokenIn: string
  tokenOut: string
  chainId: number
  amount: bigint
  type: 'exactIn' | 'exactOut'
}): Promise {
  const url = new URL('https://router.pancakeswap.finance/v0/quote')
  url.searchParams.set('tokenInAddress', params.tokenIn)
  url.searchParams.set('tokenInChainId', String(params.chainId))
  url.searchParams.set('tokenOutAddress', params.tokenOut)
  url.searchParams.set('tokenOutChainId', String(params.chainId))
  url.searchParams.set('amount', String(params.amount))
  url.searchParams.set('type', params.type)
  url.searchParams.set('maxHops', '3')
  url.searchParams.set('maxSplits', '4')

  const res = await fetch(url.toString())
  if (!res.ok) throw new Error(`Routing API error: ${res.status} ${await res.text()}`)
  return res.json()
}

// Usage
const quote = await getQuote({
  tokenIn: 'BNB',
  tokenOut: '0x0E09FaBB73Bd3Ade0a17ECC321fD13a19e81cE82', // CAKE
  chainId: 56,
  amount: BigInt('1000000000000000000'), // 1 BNB
  type: 'exactIn',
})

console.log('Output:', quote.trade.outputAmount, 'CAKE (raw)')
console.log('Price impact:', quote.trade.priceImpact, '%')

> Quote freshness: Re-fetch if the quote is more than ~15 seconds old before broadcasting. Stale quotes frequently fail with INSUFFICIENT_OUTPUT_AMOUNT.

---

Method 2: Smart Router SDK + Universal Router SDK

Best for: Frontends and backends that need full programmatic control over routing and transaction encoding. Operates entirely on-chain — no external API dependency.

Installation

npm install @pancakeswap/smart-router @pancakeswap/sdk @pancakeswap/v3-sdk @pancakeswap/universal-router-sdk viem@2.37.13

Package Roles

| Package | Role | | ----------------------------------- | ------------------------------------------------- | | @pancakeswap/smart-router | Pool fetching + best route finding | | @pancakeswap/sdk | Core types: Token, CurrencyAmount, Percent, etc. | | @pancakeswap/v3-sdk | V3-specific types: FeeAmount, pool encoding | | @pancakeswap/universal-router-sdk | Encode calldata for the Universal Router contract | | viem@2.37.13 | Ethereum client (reads, writes, signing) — pin to this version for PancakeSwap compatibility |

Step 1: Set Up Viem Clients

import { createPublicClient, createWalletClient, http } from 'viem'
import { bsc } from 'viem/chains'
import { privateKeyToAccount } from 'viem/accounts'

const publicClient = createPublicClient({
  chain: bsc,
  transport: http('https://bsc-dataseed1.binance.org'),
})

const account = privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`)
const walletClient = createWalletClient({
  account,
  chain: bsc,
  transport: http('https://bsc-dataseed1.binance.org'),
})

Step 2: Define Tokens

import { ChainId, Token } from '@pancakeswap/sdk'
import { Native } from '@pancakeswap/swap-sdk-evm'

const chainId = ChainId.BSC // 56

// Native BNB (no address)
const BNB = Native.onChain(chainId)

// ERC-20 tokens
const CAKE = new Token(
  chainId,
  '0x0E09FaBB73Bd3Ade0a17ECC321fD13a19e81cE82',
  18,
  'CAKE',
  'PancakeSwap Token',
)

const USDT = new Token(
  chainId,
  '0x55d398326f99059fF775485246999027B3197955',
  18,
  'USDT',
  'Tether USD',
)

Step 3: Fetch Candidate Pools

import { SmartRouter, PoolType } from '@pancakeswap/smart-router'
import { TradeType } from '@pancakeswap/sdk'
import { CurrencyAmount } from '@pancakeswap/swap-sdk-core'

const amountIn = CurrencyAmount.fromRawAmount(
  BNB,
  BigInt('1000000000000000000'), // 1 BNB
)

// Fetch all relevant pool types in parallel
const [v2Pools, v3Pools, stablePools] = await Promise.all([
  SmartRouter.getV2CandidatePools({
    onChainProvider: () => publicClient,
    currencyA: BNB,
    currencyB: CAKE,
  }),
  SmartRouter.getV3CandidatePools({
    onChainProvider: () => publicClient,
    subgraphProvider: undefined, // optional — speeds up pool discovery
    currencyA: BNB,
    currencyB: CAKE,
  }),
  SmartRouter.getStableCandidatePools({
    onChainProvider: () => publicClient,
    currencyA: BNB,
    currencyB: CAKE,
  }),
])

const pools = [...v2Pools, ...v3Pools, ...stablePools]

> Performance tip: If you're building a UI, consider caching pools for 30–60 seconds and only re-fetching when the user changes tokens or chain.

> Infinity (v4) pool access: The Smart Router SDK's Infinity pool integration is still evolving. For reliable Infinity CL and Infinity Bin pool access today, use Method 1 (Routing API) — it automatically considers all pool types including Infinity on BSC and Base with no extra setup required.

Step 4: Find Best Trade

const trade = await SmartRouter.getBestTrade(amountIn, CAKE, TradeType.EXACT_INPUT, {
  gasPriceWei: () => publicClient.getGasPrice(),
  maxHops: 3,
  maxSplits: 4,
  poolProvider: SmartRouter.createStaticPoolProvider(pools),
  quoteProvider: SmartRouter.createQuoteProvider({
    onChainProvider: () => publicClient,
  }),
  allowedPoolTypes: [PoolType.V2, PoolType.V3, PoolType.STABLE],
})

// Always check price impact before proceeding
if (parseFloat(trade.priceImpact.toSignificant(4)) > 2) {
  console.warn(`⚠️  High price impact: ${trade.priceImpact.toSignificant(4)}%`)
}

console.log('Output:', trade.outputAmount.toSignificant(6), CAKE.symbol)
console.log('Route:', trade.routes.map((r) => r.type).join(' + '))

Step 5: Approve Tokens

> Skip this step if the input currency is native BNB/ETH — native currency does not need approval.

import { erc20Abi } from 'viem'
import {
  PancakeSwapUniversalRouter,
  getUniversalRouterAddress,
} from '@pancakeswap/universal-router-sdk'

const PERMIT2_ADDRESS = '0x000000000022D473030F116dDEE9F6B43aC78BA3' as const

async function ensureTokenApproved(
  tokenAddress: `0x${string}`,
  owner: `0x${string}`,
  chainId: number,
) {
  // Step 1: Approve Permit2 contract (one-time per token, per wallet)
  const permit2Allowance = await publicClient.readContract({
    address: tokenAddress,
    abi: erc20Abi,
    functionName: 'allowance',
    args: [owner, PERMIT2_ADDRESS],
  })

  const MAX_UINT256 = BigInt('0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff')
  if (permit2Allowance  publicClient.getGasPrice(),
    maxHops: 3,
    maxSplits: 4,
    poolProvider: SmartRouter.createStaticPoolProvider(pools),
    quoteProvider: SmartRouter.createQuoteProvider({ onChainProvider: () => publicClient }),
  },
)

console.log('Max BNB to spend:', trade.inputAmount.toSignificant(6))

// Encode with maximumAmountIn applied automatically via slippageTolerance
const { calldata, value } = PancakeSwapUniversalRouter.swapERC20CallParameters(trade, {
  slippageTolerance: new Percent(50, 10000),
  recipient: account.address,
  deadlineOrPreviousBlockhash: deadline,
})

---

Method 3: Direct V2 Router Contract

Best for: Simple BSC swaps, Solidity integrations, or when you want zero SDK dependencies. Only supports V2 pools — no V3 or StableSwap.

V2 Router Address (BSC Mainnet)

0x10ED43C718714eb63d5aA57B78B54704E256024E

V2 Router ABI (subset)

const PANCAKE_V2_ROUTER_ABI = [
  {
    name: 'swapExactETHForTokens',
    type: 'function',
    stateMutability: 'payable',
    inputs: [
      { name: 'amountOutMin', type: 'uint256' },
      { name: 'path', type: 'address[]' },
      { name: 'to', type: 'address' },
      { name: 'deadline', type: 'uint256' },
    ],
    o

…

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [semiotic-ai](https://github.com/semiotic-ai)
- **Source:** [semiotic-ai/agentsec](https://github.com/semiotic-ai/agentsec)
- **License:** MIT
- **Homepage:** https://agentsec.sh

Install and usage instructions live in the source repository linked above.