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Version: 6.1.0 - 6.1.1

Exchange Operations Guide

TronWeb provides built-in support for the Bancor-based decentralized exchange (DEX) protocol on TRON. This allows creating token trading pairs and executing trades on-chain.

note

TRON's built-in DEX uses the Bancor algorithm for automated price discovery based on token supply and balance ratios.

Creating an Exchange​

TRX-to-Token Exchange​

Create a trading pair between TRX and a TRC-10 token:

const tx = await tronWeb.transactionBuilder.createTRXExchange(
    'TokenName',   // TRC-10 token name
    1000000000,    // token amount to deposit
);
const signedTx = await tronWeb.trx.sign(tx);
const receipt = await tronWeb.trx.sendRawTransaction(signedTx);

Token-to-Token Exchange​

Create a trading pair between two TRC-10 tokens:

const tx = await tronWeb.transactionBuilder.createTokenExchange(
    'TokenA',      // first token name
    1000000000,    // first token amount
    'TokenB',      // second token name
    2000000000,    // second token amount
);
const signedTx = await tronWeb.trx.sign(tx);
const receipt = await tronWeb.trx.sendRawTransaction(signedTx);

Managing Exchange Liquidity​

Inject Tokens​

Add liquidity to an existing exchange:

const tx = await tronWeb.transactionBuilder.injectExchangeTokens(
    exchangeId,    // exchange ID
    'TokenName',   // token to inject
    1000000000,    // amount to inject
);
const signedTx = await tronWeb.trx.sign(tx);
const receipt = await tronWeb.trx.sendRawTransaction(signedTx);

Withdraw Tokens​

Remove liquidity from an exchange:

const tx = await tronWeb.transactionBuilder.withdrawExchangeTokens(
    exchangeId,    // exchange ID
    'TokenName',   // token to withdraw
    500000000,     // amount to withdraw
);
const signedTx = await tronWeb.trx.sign(tx);
const receipt = await tronWeb.trx.sendRawTransaction(signedTx);

Trading​

Execute a trade on an exchange:

const tx = await tronWeb.transactionBuilder.tradeExchangeTokens(
    exchangeId,    // exchange ID
    'TokenName',   // token to sell
    1000000000,    // amount to sell
    500000000,     // expected minimum amount to receive
);
const signedTx = await tronWeb.trx.sign(tx);
const receipt = await tronWeb.trx.sendRawTransaction(signedTx);

Parameters:

ParameterTypeDescription
exchangeIDnumberThe exchange pair ID
tokenNamestringToken you are selling
tokenAmountSoldnumberAmount of token to sell
tokenAmountExpectednumberMinimum amount expected to receive (slippage protection)
tip

Set tokenAmountExpected to provide slippage protection. The trade will fail if the actual received amount is less than this value.

Querying Exchanges​

// List all exchanges
const exchanges = await tronWeb.trx.listExchanges();

// Get details of a specific exchange
const exchange = await tronWeb.trx.getExchangeByID(exchangeId);
console.log(exchange);
// {
//   exchange_id: 1,
//   creator_address: '...',
//   first_token_id: 'TokenA',
//   first_token_balance: 1000000000,
//   second_token_id: '_',  // '_' represents TRX
//   second_token_balance: 5000000000,
// }

// List exchanges created by a specific account
const myExchanges = await tronWeb.trx.listExchangesPaginated(limit, offset);

Bancor Price Calculation​

The Bancor algorithm ensures that:

first_token_balance × second_token_balance = constant

When you sell token A to buy token B:

Amount of B received = second_balance - (first_balance × second_balance) / (first_balance + amount_of_A_sold)

This means larger trades have higher price impact (slippage).