I run into a account on the browser.
https://solscan.io/account/41BJ8cmr4vaebFbHzxerb8YG6MmTFWLj15M6h65mUyiF
https://explorer.solana.com/address/41BJ8cmr4vaebFbHzxerb8YG6MmTFWLj15M6h65mUyiF
From browser we can see that it is off curve account. But browser show that it is “Assigned Program Id" to System Program.
How can one create account like this? An account assigned to System Program but off curve. How can the guy own this account spend tokens under it?
Yes, The account you’re looking at is an off-curve Program Derived Address (PDA). PDAs are special accounts that don't have private keys and are instead generated programmatically using findProgramAddress function with combination of seeds and public key(usually a program ID or even a wallet's public key). This makes them off-curve and impossible to control via a private key.
PDAs are "owned" by the program that created them. Even though it is assigned to the System Program, the actual control comes from the program that derived the PDA.
This is simple script how to create such accounts and control assets.
const seed = "my-seed";
const [pda, bump] = PublicKey.findProgramAddressSync(
[Buffer.from(seed)],
admin.publicKey
);
const pdaAta = getAssociatedTokenAddressSync(tokenMint, pda, true);
const ixs = [
createAssociatedTokenAccountInstruction(
admin.publicKey,
pdaAta,
pda,
tokenMint
),
createMintToInstruction(tokenMint, pdaAta, admin.publicKey, 1e9),
];
const block = await connection.getLatestBlockhash();
const tx = new VersionedTransaction(
new TransactionMessage({
payerKey: admin.publicKey,
recentBlockhash: block.blockhash,
instructions: ixs,
}).compileToV0Message()
);
tx.sign([admin]);
await connection.sendTransaction(tx).then(confirm).then(log);
console.log("pda: ", pda.toBase58());
console.log("pda ata: ", pdaAta.toBase58());
These are the addresses of the PDA and its associated token accounts (ATA) that were just created on the Devnet.
https://solscan.io/account/C6itz1Drxui8eSjmVCyKRMY87yo7EmS7MDDWxNJDjd8A?cluster=devnet https://solscan.io/account/EefAxfXWimXmk9DDjpvXDBC6GTB36HWJAMm4DvYmYfEb?cluster=devnet
