Full example of how to swap tokens with jupiter

jupiter-full-js-example.js

const { Connection, Keypair, VersionedTransaction } = require ('@solana/web3.js');
const bs58 = require ('bs58');
const axios = require('axios');

// It is recommended that you use your own RPC endpoint.
// This RPC endpoint is only for demonstration purposes so that this example will run.
const connection = new Connection('');

const keypair = Keypair.fromSecretKey(bs58.decode(''));

async function swapSolToUsdc() {
    try {
      // Swapping SOL to USDC with input 0.1 SOL and 0.5% slippage
      const quoteResponse = await axios.get('https://quote-api.jup.ag/v6/quote', {
        params: {
          inputMint: 'So11111111111111111111111111111111111111112',
          outputMint: 'EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v',
          amount: 100000000, // 0.1 SOL in lamports
          slippageBps: 50
        }
      });
      console.log({ quoteResponse: quoteResponse.data });
  
      // Get serialized transactions for the swap
      const swapResponse = await axios.post('https://quote-api.jup.ag/v6/swap', {
        quoteResponse: quoteResponse.data,
        userPublicKey: keypair.publicKey.toString(),
        wrapAndUnwrapSol: true,
        prioritizationFeeLamports: 10000
      }, {
        headers: {
          'Content-Type': 'application/json'
        }
      });
  
      const { swapTransaction } = swapResponse.data;
  
      // Deserialize the transaction
      const swapTransactionBuf = Buffer.from(swapTransaction, 'base64');
      var transaction = VersionedTransaction.deserialize(swapTransactionBuf);
      console.log(transaction);
  
      // Sign the transaction
      transaction.sign([keypair]);

      // Replace the blockhash
      const bhInfo = (await connection.getLatestBlockhashAndContext('finalized'));
      transaction.message.recentBlockhash = bhInfo.value.blockhash;
  
      // Simulate
      const simulation = await connection.simulateTransaction(transaction, { commitment: 'processed' });
      if (simulation.value.err) {
        throw new Error('Simulate failed: ' + simulation.value.err);
      }
      const signature = await connection.sendTransaction(transaction, { skipPreflight: true, preflightCommitment: 'processed' });
      const confirmation = await connection.confirmTransaction(signature, { commitment: 'finalized', lastValidBlockHeight: bhInfo.value.lastValidBlockHeight });
      if (confirmation.value.err) {
        throw new Error('Transaction failed: ' + confirmation.value.err);
      }
      console.log(`https://solscan.io/tx/${signature}`);
    } catch (error) {
      console.error('Error during swap:', error);
    }
  }
  
  swapSolToUsdc();

Line 47+48 and line 44 must be swopped since signing inc. blockhash

This worked only one time and other times I get always

Signature 5kfToCqGEiwPa1gSiKHHvyYchmmUNPXTfDCkhaMtYtG9zjLY57tb6Z5hfpAdJcLgLVfdd8278QSG1YbbFfDofwjR has expired: block height exceeded. at Connection.confirmTransactionUsingBlockHeightExceedanceStrategy

This worked only one time and other times I get always

Signature 5kfToCqGEiwPa1gSiKHHvyYchmmUNPXTfDCkhaMtYtG9zjLY57tb6Z5hfpAdJcLgLVfdd8278QSG1YbbFfDofwjR has expired: block height exce

try with const bhInfo = await connection.getLatestBlockhash('finalized');