swap

This section contains SDK example for performing swap in DEX

In this section, to illustrate all three possible types of a swap, we will do following exchange chain

1. swap 1 TON to STON (ton to jetton swap)

2. swap STON to GEMSTON (jetton to jetton swap)

3. swap GEMSTON back to TON (jetton to ton swap)

Swap TON to jetton

import TonWeb from "tonweb";
import { DEX, pTON } from "@ston-fi/sdk";

const router = new DEX.v1.Router({
  tonApiClient: new TonWeb.HttpProvider(),
});

// swap 1 TON to STON but not less than 1 nano STON
const txParams = await router.buildSwapTonToJettonTxParams({
  userWalletAddress: "", // ! replace with your address
  proxyTonAddress: pTON.v1.address,
  offerAmount: new TonWeb.utils.BN("1000000000"),
  askJettonAddress: "EQA2kCVNwVsil2EM2mB0SkXytxCqQjS4mttjDpnXmwG9T6bO", // STON
  minAskAmount: new TonWeb.utils.BN("1"),
  queryId: 12345,
});

// To execute the transaction, you need to send a transaction to the blockchain.
// This code will be different based on the wallet you are using to send the tx from
// logging is used for demonstration purposes
console.log({
  to: txParams.to,
  amount: txParams.gasAmount,
  payload: txParams.payload,
});

Swap jetton to jetton

import TonWeb from "tonweb";
import { DEX, pTON } from "@ston-fi/sdk";

const router = new DEX.v1.Router({
  tonApiClient: new TonWeb.HttpProvider(),
});

// swap 1 STON to GEMSTON but not less than 1 nano GEMSTON
const txParams = await router.buildSwapJettonToJettonTxParams({
  userWalletAddress: "", // ! replace with your address
  offerJettonAddress: "EQA2kCVNwVsil2EM2mB0SkXytxCqQjS4mttjDpnXmwG9T6bO", // STON
  offerAmount: new TonWeb.utils.BN("1000000000"),
  askJettonAddress: "EQBX6K9aXVl3nXINCyPPL86C4ONVmQ8vK360u6dykFKXpHCa", // GEMSTON
  minAskAmount: new TonWeb.utils.BN("1"),
  queryId: 12345,
});

// To execute the transaction, you need to send a transaction to the blockchain.
// This code will be different based on the wallet you are using to send the tx from
// logging is used for demonstration purposes
console.log({
  to: txParams.to,
  amount: txParams.gasAmount,
  payload: txParams.payload,
});

Swap jetton to TON

import TonWeb from "tonweb";
import { DEX, pTON } from "@ston-fi/sdk";

const router = new DEX.v1.Router({
  tonApiClient: new TonWeb.HttpProvider(),
});

// swap 1 GEMSTON to TON but not less than 1 nano TON
const txParams = await router.buildSwapJettonToTonTxParams({
  userWalletAddress: "", // ! replace with your address
  offerJettonAddress: "EQBX6K9aXVl3nXINCyPPL86C4ONVmQ8vK360u6dykFKXpHCa", // GEMSTON
  offerAmount: new TonWeb.utils.BN("1000000000"),
  proxyTonAddress: pTON.v1.address,
  minAskAmount: new TonWeb.utils.BN("1"),
  queryId: 12345,
});

// To execute the transaction, you need to send a transaction to the blockchain.
// This code will be different based on the wallet you are using to send the tx from
// logging is used for demonstration purposes
console.log({
  to: txParams.to,
  amount: txParams.gasAmount,
  payload: txParams.payload,
});

Recommended gas values

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

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

Formulas:

pTON -> Jetton

// 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

Jetton -> Jetton

// (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

// (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