How to send bounceable transaction?

[mahnunchik]

How to send bounceable transfer of native TON?

According to the documentation:

• https://docs.ton.org/develop/smart-contracts/tutorials/wallet
• https://docs.ton.org/develop/smart-contracts/messages
• https://docs.ton.org/develop/smart-contracts/guidelines/non-bouncable-messages

To send bounceable transfer it is required to set bounce flag in internal message and use sending mode +16.

+16 | In the case of action fail - bounce transaction

It is uninitialized wallet: https://testnet.tonviewer.com/EQAfs3mJctSyXlJpR89j6h1T7fYJ_nBt8hGbfkDUaET7x9p8

Code sample:

import { WalletContractV4, TonClient, internal } from '@ton/ton';

const client = new TonClient({
  endpoint: 'https://testnet.toncenter.com/api/v2/jsonRPC',
});

const walletContract = client.open(wallet);
const seqno = await walletContract.getSeqno();

const transfer = await walletContract.createTransfer({
  secretKey: key.secretKey,
  seqno: seqno,
  sendMode: 16,
  messages: [
    internal({
      to: 'EQAfs3mJctSyXlJpR89j6h1T7fYJ_nBt8hGbfkDUaET7x9p8',
      value: 12345,
      bounce: true,
      // sender is fresh wallet so init it
      init: wallet.init,
    })
  ],
});

await walletContract.send(transfer);

Expected behaviour

Transaction amount is returned to sender minus fee

Actual bahaviour

An infinite number of attempts has spent the sender's entire balance https://testnet.tonviewer.com/0QA3tr_6AZK9qMQy46a7ULtriizI7iXeiPufNxib4a7b6eU8

[mahnunchik]

The same question on TON overflow https://answers.ton.org/question/1670952138383036416/how-to-send-bounceable-transaction-or-transaction-spent-the-sender-s-entire-balance

[mahnunchik]

Ok, i'm trying to send bounce: true transaction with sendMode set to 2 and 3.

sendMode=3 and amount=100 000

const transfer = await walletContract.createTransfer({
  secretKey: key.secretKey,
  seqno: seqno,
  sendMode: 3,
  messages: [
    internal({
      to: 'EQC2u1E2lxn_p1HZH61ByEOs706E0ijCNXOXnDTXoZ31-hNw',
      value: 100_000,
      bounce: true,
    }),
  ],
});

Transaction NOT bounced back and destination account received 0.0001 TON https://testnet.tonviewer.com/transaction/31ee4bdef19efa45a37b24f59ab500817187e1fe40681eb0bbfaf7fa21284cba

How it is possible?

sendMode=2 and amount=1 000 000

const transfer = await walletContract.createTransfer({
  secretKey: key.secretKey,
  seqno: seqno,
  sendMode: 2,
  messages: [
    internal({
      to: 'EQBQRxKlTcoc_ZVpBiLyfauHxL3MO2TNefrKnr7s-OqKP_Go',
      value: 1_000_000,
      bounce: true,
    }),
  ],
});

Transaction NOT bounced back (the entire amount was spent on fee): https://testnet.tonviewer.com/transaction/5a91a594a5c5d5714481aecfca6fb7bff354100b34e5f22af139201c2fa24b82

sendMode=2 and amount=10 000 000

const transfer = await walletContract.createTransfer({
  secretKey: key.secretKey,
  seqno: seqno,
  sendMode: 2,
  messages: [
    internal({
      to: 'EQDDzK-DSq5YMABLNYk4S3ZkivasHhOWe9JJqDcVLSUnQ6qf',
      value: 10_000_000,
      bounce: true,
    }),
  ],
});

Transaction successfully bounced back: https://testnet.tonviewer.com/transaction/9719e6c60ab9992366c465cf49358efaab0e93ac743d986b01afa01438ef2aaf

sendMode=3 and amount=10 000 000

const transfer = await walletContract.createTransfer({
  secretKey: key.secretKey,
  seqno: seqno,
  sendMode: 3,
  messages: [
    internal({
      to: 'EQDDzK-DSq5YMABLNYk4S3ZkivasHhOWe9JJqDcVLSUnQ6qf',
      value: 10_000_000,
      bounce: true,
    }),
  ],
});

Transaction successfully bounced back: https://testnet.tonviewer.com/transaction/3fcff5b741b6e7bbd02b493afd32bb7c218fc9a518c1c819dd7ba337ef9c0207

sendMode=3 and amount=1 000 000

const transfer = await walletContract.createTransfer({
  secretKey: key.secretKey,
  seqno: seqno,
  sendMode: 3,
  messages: [
    internal({
      to: 'EQBQRxKlTcoc_ZVpBiLyfauHxL3MO2TNefrKnr7s-OqKP_Go',
      value: 1_000_000,
      bounce: true,
    }),
  ],
});

Transaction successfully bounced back (the entire amount was spent on fee): https://testnet.tonviewer.com/transaction/ef610379982ad3334407c5c9ae35dd7f3529b354b21855f39b45db65b7658756