> For the complete documentation index, see [llms.txt](https://docs.ston.fi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ston.fi/developer-section/dex/migration/legacy/v0.4/swap.md).

# Swap

Legacy v0.4 token swap guide - execute swaps using deprecated SDK methods

## Jetton1/Jetton2

Perform a swap operation.

```typescript
import TonWeb from 'tonweb';

import { Router, ROUTER_REVISION, ROUTER_REVISION_ADDRESS } from '@ston-fi/sdk';

/**
 * This example shows how to swap two jettons using the router contract
 */
(async () => {
  const WALLET_ADDRESS = ''; // ! replace with your address
  const JETTON0 = 'EQA2kCVNwVsil2EM2mB0SkXytxCqQjS4mttjDpnXmwG9T6bO'; // STON
  const JETTON1 = 'EQBynBO23ywHy_CgarY9NK9FTz0yDsG82PtcbSTQgGoXwiuA'; // jUSDT

  const provider = new TonWeb.HttpProvider();

  const router = new Router(provider, {
    revision: ROUTER_REVISION.V1,
    address: ROUTER_REVISION_ADDRESS.V1,
  });

  // transaction to swap 1.0 JETTON0 to JETTON1 but not less than 1 nano JETTON1
  const swapTxParams = await router.buildSwapJettonTxParams({
    // address of the wallet that holds offerJetton you want to swap
    userWalletAddress: WALLET_ADDRESS,
    // address of the jetton you want to swap
    offerJettonAddress: JETTON0,
    // amount of the jetton you want to swap
    offerAmount: new TonWeb.utils.BN('1000000000'),
    // address of the jetton you want to receive
    askJettonAddress: JETTON1,
    // minimal amount of the jetton you want to receive as a result of the swap.
    // If the amount of the jetton you want to receive is less than minAskAmount
    // the transaction will bounce
    minAskAmount: new TonWeb.utils.BN(1),
    // query id to identify your transaction in the blockchain (optional)
    queryId: 12345,
    // address of the wallet to receive the referral fee (optional)
    referralAddress: undefined,
  });

  // to execute the transaction you need to send transaction to the blockchain
  // (replace with your wallet implementation, logging is used for demonstration purposes)
  console.log({
    to: swapTxParams.to,
    amount: swapTxParams.gasAmount,
    payload: swapTxParams.payload,
  });

  // reverse transaction is the same,
  // you just need to swap `offerJettonAddress` and `askJettonAddress` values
  // and adjust `offerAmount` and `minAskAmount` accordingly
})();

```

## Proxy-ton/Jetton

Perform a swap operation using proxy-ton.

```typescript
import TonWeb from 'tonweb';

import { Router, ROUTER_REVISION, ROUTER_REVISION_ADDRESS } from '@ston-fi/sdk';

/**
 * This example shows how to swap TON to jetton using the router contract
 */
(async () => {
  const WALLET_ADDRESS = ''; // ! replace with your address
  const JETTON0 = 'EQA2kCVNwVsil2EM2mB0SkXytxCqQjS4mttjDpnXmwG9T6bO'; // STON
  const PROXY_TON = 'EQCM3B12QK1e4yZSf8GtBRT0aLMNyEsBc_DhVfRRtOEffLez'; // ProxyTON

  const provider = new TonWeb.HttpProvider();

  const router = new Router(provider, {
    revision: ROUTER_REVISION.V1,
    address: ROUTER_REVISION_ADDRESS.V1,
  });

  // Because TON is not a jetton, to be able to swap TON to jetton
  // you need to use special SDK method to build transaction to swap TON to jetton
  // using proxy jetton contract.

  // transaction to swap 1.0 TON to JETTON0 but not less than 1 nano JETTON0
  const tonToJettonTxParams = await router.buildSwapProxyTonTxParams({
    // address of the wallet that holds TON you want to swap
    userWalletAddress: WALLET_ADDRESS,
    proxyTonAddress: PROXY_TON,
    // amount of the TON you want to swap
    offerAmount: new TonWeb.utils.BN('1000000000'),
    // address of the jetton you want to receive
    askJettonAddress: JETTON0,
    // minimal amount of the jetton you want to receive as a result of the swap.
    // If the amount of the jetton you want to receive is less than minAskAmount
    // the transaction will bounce
    minAskAmount: new TonWeb.utils.BN(1),
    // query id to identify your transaction in the blockchain (optional)
    queryId: 12345,
    // address of the wallet to receive the referral fee (optional)
    referralAddress: undefined,
  });

  // to execute the transaction you need to send transaction to the blockchain
  // (replace with your wallet implementation, logging is used for demonstration purposes)
  console.log({
    to: tonToJettonTxParams.to,
    amount: tonToJettonTxParams.gasAmount,
    payload: tonToJettonTxParams.payload,
  });

  // reverse transaction is just a regular swap transaction where `askJettonAddress` is a ProxyTon address.
  // see swap example for more details
})();
```

## Recommended gas values

Below are recommended values for TON sent and forward gas for each type of the swap:

| Type                 | Tx TON                | Forward TON |
| -------------------- | --------------------- | ----------- |
| `Jetton` -> `Jetton` | `0.265`               | `0.205`     |
| `Jetton` -> `pTON`   | `0.185`               | `0.125`     |
| `pTON` -> `Jetton`   | `swap_amount + 0.215` | `0.215`     |

### Formulas:

#### `Jetton` -> `Jetton`

```typescript
// (jetton_notification + swap) + (pay_to + jetton_transfer) * 2
fwd_amount = 0.045 + (0.02 + 0.06) * 2 // = 0.205
// jetton_transfer + fwd_amount
tx_amount = 0.06 + fwd_amount // = 0.265
```

#### `Jetton` -> `pTON`

```typescript
// (jetton_notification + swap) + (pay_to + pton_transfer) * 2
fwd_amount = 0.045 + (0.02 + 0.02) * 2 // = 0.125
// jetton_transfer + fwd_amount
tx_amount = 0.06 + fwd_amount // = 0.185
```

#### `pTON` -> `Jetton`

```typescript
// pton_transfer + (pay_to + jetton_transfer) * 2 + (jetton_notification + swap)
fwd_amount = 0.01 + (0.02 + 0.06) * 2 + 0.045 // = 0.215
// jetton_transfer + fwd_amount
tx_amount = swap_amount + fwd_amount // = swap_amount + 0.215
```


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