Send USDT
on TRON —
cheaply and safely.

import TronWeb from "tronweb";
const BASE = "https://trontransfer.com";
const tw = new TronWeb({ fullHost: "https://api.trongrid.io" }); // + your signer

async function sendUsdt(from, to, amountUsdt) {
  // 1) config — where the fee goes + the USDT contract
  const cfg  = await (await fetch(`${BASE}/config`)).json();
  // 2) the exact fee for THIS recipient (warm vs cold)
  const rcpt  = await (await fetch(`${BASE}/recipient?addr=${to}`)).json();
  const price = rcpt.pricing || cfg.pricing;

  // 3) build BOTH txs: the TRX fee + the USDT transfer
  let feeTx = await tw.transactionBuilder.sendTrx(cfg.collectAddress, price.feeSun, from);
  const units = Math.round(amountUsdt * 1e6); // USDT = 6 decimals
  let usdtTx = (await tw.transactionBuilder.triggerSmartContract(
    cfg.usdtContract, "transfer(address,uint256)", { feeLimit: 100000000 },
    [{ type: "address", value: to }, { type: "uint256", value: units }], from
  )).transaction;

  // 4) extend expiration so the relay can rent energy in time
  feeTx  = await tw.transactionBuilder.extendExpiration(feeTx, 300);
  usdtTx = await tw.transactionBuilder.extendExpiration(usdtTx, 300);

  // 5) sign BOTH (TronWeb returns the fully-signed tx object)
  const feeSigned  = await tw.trx.sign(feeTx);
  const usdtSigned = await tw.trx.sign(usdtTx);

  // 6) submit — the relay broadcasts (you never do)
  const res = await fetch(`${BASE}/v1/transfers`, {
    method: "POST", headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ feeTx: feeSigned, usdtTx: usdtSigned }),
  });
  const out = await res.json();
  if (!out.ok || !out.usdtTxid) throw new Error(out.message);
  return out; // { ok:true, usdtTxid, feeTxid, ... }
}

const { TronWeb } = require("tronweb");   // Node 18+ · npm i tronweb
const BASE = "https://trontransfer.com";

// Your key signs — no browser wallet. Keep it in env/KMS, never in code.
const tw = new TronWeb({
  fullHost: "https://api.trongrid.io",
  privateKey: process.env.TRON_PRIVATE_KEY,
});
const from = tw.defaultAddress.base58;        // the key's own address

async function sendUsdt(to, amountUsdt) {
  // 1) config + this recipient's exact fee (warm vs cold)
  const cfg   = await (await fetch(`${BASE}/config`)).json();
  const rcpt  = await (await fetch(`${BASE}/recipient?addr=${to}`)).json();
  const price = rcpt.pricing || cfg.pricing;

  // 2) build BOTH txs: the TRX fee + the USDT transfer
  let feeTx   = await tw.transactionBuilder.sendTrx(cfg.collectAddress, price.feeSun, from);
  const units = Math.round(amountUsdt * 1e6); // USDT = 6 decimals
  let usdtTx  = (await tw.transactionBuilder.triggerSmartContract(
    cfg.usdtContract, "transfer(address,uint256)", { feeLimit: 100000000 },
    [{ type: "address", value: to }, { type: "uint256", value: units }], from
  )).transaction;

  // 3) extend expiration so the relay can rent energy in time
  feeTx  = await tw.transactionBuilder.extendExpiration(feeTx, 300);
  usdtTx = await tw.transactionBuilder.extendExpiration(usdtTx, 300);

  // 4) sign BOTH with your private key (you never broadcast)
  const feeSigned  = await tw.trx.sign(feeTx);
  const usdtSigned = await tw.trx.sign(usdtTx);

  // 5) submit — the relay broadcasts (you never do)
  const res = await fetch(`${BASE}/v1/transfers`, {
    method: "POST", headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ feeTx: feeSigned, usdtTx: usdtSigned }),
  });
  const out = await res.json();
  if (!out.ok || !out.usdtTxid) throw new Error(out.message);
  return out; // { ok:true, usdtTxid, feeTxid, ... }
}