Build swap applications on Solana#

In this guide, we will provide a use case for Solana token exchange through the OKX DEX. The process includes:

Set up your environment
Obtain the token account address for toTokenAddress
Obtain the exchange path
Deserialize and sign
Execute the transaction

1. Set up your environment#

Import the necessary Node.js libraries and set up your environment variables. Define helper functions and assembly parameters Node.js Environment Settings.

Additionally, you need to import the following libraries after completing the above steps.

const bs58 = require('bs58');
  const solanaWeb3 = require('@solana/web3.js');
  const {Connection} = require("@solana/web3.js");
  npm i bs58
  npm i @solana/web3.js

2. Obtain the exchange path and callData#

Tip

Solana's NativeTokenAddress is 11111111111111111111111111111111.

Use the /swap endpoint to retrieve detailed swap paths and callData.

Here is an example of swapping SOL to wSOL on the Solana chain:

curl --location --request GET 'https://www.okx.com/api/v5/dex/aggregator/swap?amount=1000&chainId=501&fromTokenAddress=11111111111111111111111111111111&toTokenAddress=So11111111111111111111111111111111111111112&userWalletAddress=3cUbuUEJkcgtzGxvsukksNzmgqaUK9jwFS5pqxxxxxxx&slippage=0.05' \

3. Deserialize and sign#

Note

The callData here is obtained from the /swap endpoint.

async function signTransaction(callData, privateKey) {

    // decode
    const transaction = bs58.decode(callData)

    let tx
    // There are two types of callData, one is the old version and the other is the new version.
    try {
        tx = solanaWeb3.Transaction.from(transaction)
    } catch (error) {
        tx = solanaWeb3.VersionedTransaction.deserialize(transaction)
    }

    // Replace the latest block hash
    const recentBlockHash = await connection.getLatestBlockhash();


    if (tx instanceof solanaWeb3.VersionedTransaction) {
        tx.message.recentBlockhash = recentBlockHash.blockhash;
    } else {
        tx.recentBlockhash = recentBlockHash.blockhash
    }



    let feePayer = solanaWeb3.Keypair.fromSecretKey(bs58.decode(privateKey))
    // sign
    if (tx instanceof solanaWeb3.VersionedTransaction) {
    // v0 callData
        tx.sign([feePayer])
      } else {
    // legacy callData
        tx.partialSign(feePayer)
      }
    console.log(tx)


}

// 'xxxxxxx' means your privateKey
signTransaction(callData,'xxxxxxx')

4. Execute the transaction#

const txId =  await connection.sendRawTransaction(tx.serialize());

  console.log('txId:', txId)

  // Verify whether it has been broadcast on the chain.
  await connection.confirmTransaction(txId);
  console.log(`https://solscan.io/tx/${txId}`);

DEX API

Build swap applications on the EVM network

DEX API

Build swap applications on the Ton network

Table of contents

1. Set up your environment

2. Obtain the exchange path and callData

3. Deserialize and sign

4. Execute the transaction