Sponsored Transactions

import { Transaction } from '@mysten/sui/transactions';

const userKeypair = /* user's keypair */;
const sponsorKeypair = /* sponsor's keypair */;

// User creates transaction
const tx = new Transaction();
tx.transferObjects(
  [tx.splitCoins(tx.gas, [1000000])],
  recipient
);
tx.setSender(userKeypair.getPublicKey().toSuiAddress());
tx.setGasOwner(sponsorKeypair.getPublicKey().toSuiAddress());

// User signs
const userSignature = await userKeypair.signTransaction(
  await tx.build({ client })
);

// Sponsor signs
const sponsorSignature = await sponsorKeypair.signTransaction(
  await tx.build({ client })
);

// Execute with both signatures
const result = await client.executeTransactionBlock({
  transactionBlock: await tx.build({ client }),
  signature: [
    userSignature.signature,
    sponsorSignature.signature,
  ],
});