How do I "unwrap SOL" using the web3 sdk? - solana

Question

I need to unwrap some SOL using the web3 sdk. I'm wondering, Is it just a simple transfer from the wrapped account into SOL account or is it more complicated than that? Below Is just some sample code I've setup.
const emptyWSolAccount = async (amount:any) => {
const wsolAddress = await Token.getAssociatedTokenAddress(
ASSOCIATED_TOKEN_PROGRAM_ID,
TOKEN_PROGRAM_ID,
new PublicKey("So11111111111111111111111111111111111111112"),
wallet.publicKey
);
const wsolAccount = await connection.getAccountInfo(wsolAddress);
if (wsolAccount) {
const transaction = new Transaction({
feePayer: wallet.publicKey,
});
const instructions = [];
const lamports = amount * LAMPORTS_PER_SOL;
instructions.push(
SystemProgram.transfer({
fromPubkey: wsolAddress,
toPubkey: wallet.publicKey,
lamports: lamports, // 1 sol
})
);
transaction.add(...instructions);
transaction.recentBlockhash = await (
await connection.getRecentBlockhash()
).blockhash;
transaction.partialSign(wallet.payer);
const result = await connection.sendTransaction(transaction, [
wallet.payer,
]);
console.log({ result });
return { result };
}
return ;
};

Answer 1

This is not really explained anywhere, but unwrapping SOL actually means closing the wrapped SOL account.
So instead of using a SystemProgram.transfer instruction, you'll do:
instructions.push(
splToken.instructions.createCloseAccountInstruction(
wsolAddress,
wallet.publicKey,
wallet.publicKey,
)
);
This closes wsolAddress and sends the contents to wallet, assuming that wallet is the owner.
You can see the CLI implementation at https://github.com/solana-labs/solana-program-library/blob/3db53e278b543a040d3c970797b6be6f9ea5aef9/token/cli/src/main.rs#L1139-L1194