How to deserialize transactions in @solana/web3.js v2?

Question

I'm working with Raydium and Jupiter swap APIs, which return serialized transactions that need to be deserialized before sending. In the older version of @solana/web3.js, this was done using VersionedTransaction.deserialize() or Transaction.from().

With @solana/web3.js v2, these methods no longer exist. Here's an example of what I'm trying to convert:

// Old code
const allTxBuf = swapTransactions.data.map((tx) => Buffer.from(tx.transaction, 'base64'))
const allTransactions = allTxBuf.map((txBuf) =>
  isV0Tx ? VersionedTransaction.deserialize(txBuf) : Transaction.from(txBuf)
)

The transactions come from API endpoints like Raydium's swap endpoint:

const { data: swapTransactions } = await axios.post<{
  data: { transaction: string }[]
}>('/transaction/swap-base-in', {
  // ... swap parameters
})

What's the equivalent way to deserialize these transactions using the new version of @solana/web3.js?

Answer 1

Okay, i found it. In v2, you need to use transaction decoders to deserialize transactions. Here's how:

1. First, get a transaction decoder:

const transactionDecoder = getTransactionDecoder();

2. Then use it to decode the transaction buffer:

const decodedTx = transactionDecoder.decode(txBuf);