Swapping

Execute token swaps in CPMM pools. The SDK supports both base-input (fixed input amount) and base-output (fixed output amount) swaps.

---

Base-input swap (exact input)

Specify the exact amount of tokens to sell. The SDK calculates how many tokens you receive.

import {
  ApiV3PoolInfoStandardItemCpmm,
  CpmmKeys,
  CpmmParsedRpcData,
  CurveCalculator,
  FeeOn,
  TxVersion,
} from '@raydium-io/raydium-sdk-v2'
import { NATIVE_MINT } from '@solana/spl-token'
import BN from 'bn.js'
import { initSdk } from '../config'

const swap = async () => {
  const raydium = await initSdk()

  const poolId = '7JuwJuNU88gurFnyWeiyGKbFmExMWcmRZntn9imEzdny'
  const inputAmount = new BN(100)
  const inputMint = NATIVE_MINT.toBase58()

  let poolInfo: ApiV3PoolInfoStandardItemCpmm
  let poolKeys: CpmmKeys | undefined
  let rpcData: CpmmParsedRpcData

  if (raydium.cluster === 'mainnet') {
    const data = await raydium.api.fetchPoolById({ ids: poolId })
    poolInfo = data[0] as ApiV3PoolInfoStandardItemCpmm
    rpcData = await raydium.cpmm.getRpcPoolInfo(poolInfo.id, true)
  } else {
    const data = await raydium.cpmm.getPoolInfoFromRpc(poolId)
    poolInfo = data.poolInfo
    poolKeys = data.poolKeys
    rpcData = data.rpcData
  }

  if (inputMint !== poolInfo.mintA.address && inputMint !== poolInfo.mintB.address)
    throw new Error('input mint does not match pool')

  const baseIn = inputMint === poolInfo.mintA.address

  // Compute the swap off-chain
  const swapResult = CurveCalculator.swapBaseInput(
    inputAmount,
    baseIn ? rpcData.baseReserve : rpcData.quoteReserve,
    baseIn ? rpcData.quoteReserve : rpcData.baseReserve,
    rpcData.configInfo!.tradeFeeRate,
    rpcData.configInfo!.creatorFeeRate,
    rpcData.configInfo!.protocolFeeRate,
    rpcData.configInfo!.fundFeeRate,
    rpcData.feeOn === FeeOn.BothToken || rpcData.feeOn === FeeOn.OnlyTokenB
  )

  /**
   * swapResult.inputAmount   -> actual input after fees
   * swapResult.outputAmount  -> tokens received
   * swapResult.tradeFee      -> fee charged on input mint
   */

  const { execute } = await raydium.cpmm.swap({
    poolInfo,
    poolKeys,
    inputAmount,
    swapResult,
    slippage: 0.001, // 0.1% — range: 1 (100%) to 0.0001 (0.01%)
    baseIn,
    txVersion: TxVersion.V0,
    // optional: set up priority fee here
    // computeBudgetConfig: {
    //   units: 600000,
    //   microLamports: 4659150,
    // },
  })

  const { txId } = await execute({ sendAndConfirm: true })
  console.log(`swapped: ${poolInfo.mintA.symbol} to ${poolInfo.mintB.symbol}:`, {
    txId: `https://explorer.solana.com/tx/${txId}`,
  })
}

swap()

---

Base-output swap (exact output)

Specify the exact amount of tokens to receive. The SDK calculates how many tokens you need to sell.

import {
  ApiV3PoolInfoStandardItemCpmm,
  CpmmKeys,
  CpmmParsedRpcData,
  CurveCalculator,
  FeeOn,
  TxVersion,
} from '@raydium-io/raydium-sdk-v2'
import { PublicKey } from '@solana/web3.js'
import BN from 'bn.js'
import { initSdk } from '../config'

const swapBaseOut = async () => {
  const raydium = await initSdk()

  const poolId = '7JuwJuNU88gurFnyWeiyGKbFmExMWcmRZntn9imEzdny'
  const outputAmount = new BN(1_000_000_000)
  const outputMint = new PublicKey('EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v')

  let poolInfo: ApiV3PoolInfoStandardItemCpmm
  let poolKeys: CpmmKeys | undefined
  let rpcData: CpmmParsedRpcData

  if (raydium.cluster === 'mainnet') {
    const data = await raydium.api.fetchPoolById({ ids: poolId })
    poolInfo = data[0] as ApiV3PoolInfoStandardItemCpmm
    rpcData = await raydium.cpmm.getRpcPoolInfo(poolInfo.id, true)
  } else {
    const data = await raydium.cpmm.getPoolInfoFromRpc(poolId)
    poolInfo = data.poolInfo
    poolKeys = data.poolKeys
    rpcData = data.rpcData
  }

  if (
    outputMint.toBase58() !== poolInfo.mintA.address &&
    outputMint.toBase58() !== poolInfo.mintB.address
  )
    throw new Error('output mint does not match pool')

  const baseIn = outputMint.toBase58() === poolInfo.mintB.address

  // Clamp output to available reserves
  const reserveKey = baseIn ? 'quoteReserve' : 'baseReserve'
  const clampedOutput = outputAmount.gt(rpcData[reserveKey])
    ? rpcData[reserveKey].sub(new BN(1))
    : outputAmount

  const swapResult = CurveCalculator.swapBaseOutput(
    clampedOutput,
    baseIn ? rpcData.baseReserve : rpcData.quoteReserve,
    baseIn ? rpcData.quoteReserve : rpcData.baseReserve,
    rpcData.configInfo!.tradeFeeRate,
    rpcData.configInfo!.creatorFeeRate,
    rpcData.configInfo!.protocolFeeRate,
    rpcData.configInfo!.fundFeeRate,
    rpcData.feeOn === FeeOn.BothToken || rpcData.feeOn === FeeOn.OnlyTokenB
  )

  /**
   * swapResult.sourceAmountSwapped       -> input amount needed
   * swapResult.destinationAmountSwapped   -> output amount received
   * swapResult.tradeFee                   -> fee charged on input mint
   */

  const { execute } = await raydium.cpmm.swap({
    poolInfo,
    poolKeys,
    inputAmount: new BN(0), // ignored when fixedOut is true
    fixedOut: true,
    swapResult,
    slippage: 0.001, // 0.1%
    baseIn,
    txVersion: TxVersion.V0,
    // optional: set up priority fee here
    // computeBudgetConfig: {
    //   units: 600000,
    //   microLamports: 465915,
    // },
  })

  const { txId } = await execute({ sendAndConfirm: true })
  console.log('swapped:', { txId: `https://explorer.solana.com/tx/${txId}` })
}

swapBaseOut()

---

Swap parameters

Parameter	Type	Description
poolInfo	object	Pool info from API or RPC.
poolKeys	object	Pool keys. Required for devnet.
inputAmount	BN	Amount of input tokens (base-input). Ignored when fixedOut: true.
fixedOut	boolean	Set true for base-output swaps. Default false.
swapResult	object	Pre-computed swap result from CurveCalculator.swapBaseInput() or CurveCalculator.swapBaseOutput().
slippage	number	Slippage tolerance as a decimal. 0.001 = 0.1%. Range: 1 (100%) to 0.0001 (0.01%).
baseIn	boolean	true if swapping mintA → mintB, false for mintB → mintA.
txVersion	TxVersion	Transaction version.

CurveCalculator

The CurveCalculator computes swap amounts off-chain before submitting the transaction.

Method	Description
swapBaseInput()	Given exact input amount, compute output and fees.
swapBaseOutput()	Given desired output amount, compute required input.

Both methods take the same fee parameters from the pool's configInfo:

Parameter	Description
tradeFeeRate	Fee taken from swap input, in units of 1e-6.
creatorFeeRate	Additional fee sent to the pool creator.
protocolFeeRate	Share of trade fee sent to Raydium protocol.
fundFeeRate	Share of trade fee sent to Raydium treasury.

Always fetch fresh RPC data (getRpcPoolInfo) before computing swaps to get the latest reserves and avoid stale quotes.