TRON API for USDT Transactions: Sending TRC20 and Managing Energy

If you run a payment flow on TRON, energy is the main thing to design around. This overview covers the moving parts of a tron api for USDT transactions. The official TRON developer docs have the full reference.

Tronscan API vs TronGrid: which to use

Use the api tronscan offers for explorer-style data, and the trongrid api for node access and broadcasting. Most apps need TronGrid.

Get an API key

Sign up at TronGrid and create a key, or create a tronscan api key in your Tronscan account. Send it in the request header.

The building blocks

Piece	What it does
Full node or TronGrid	Reads chain data and broadcasts transactions
TronWeb or a similar SDK	Builds and signs transactions
USDT contract	TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t
Energy source	Staked TRX, rented energy or burned TRX

List transactions of an address

This tron api get transactions call was tested against TronGrid:

curl "https://api.trongrid.io/v1/accounts/ADDRESS/transactions/trc20?limit=20&contract_address=TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t"

Check a USDT TRC20 balance

GET /v1/accounts/ADDRESS returns the account, and its trc20 list holds USDT balances in units of 0.000001 USDT.

Send USDT with TronWeb

A tronweb send usdt call with this tron api usdt flow:

const usdt = await tronWeb.contract().at('TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t');
const txid = await usdt.transfer(to, 1_000_000).send({ feeLimit: 15_000_000 });

That sends 1 USDT with a 15 TRX fee limit. Test it on a small amount first.

A USDT transfer in five steps

1. Check the recipient. Call balanceOf on the USDT contract. Zero means the double-energy case.
2. Check the sender’s resources. Read available energy and bandwidth with getaccountresource.
3. Get energy if needed. Stake, rent, or accept a TRX burn.
4. Build and sign a transfer(to, amount) call. USDT has 6 decimals. Sign locally and never send a private key to a remote node.
5. Broadcast and confirm. A transaction is considered final after about 19 blocks, roughly a minute.

Fee limit

Every smart-contract call has a fee_limit, the most TRX it may burn. Too low, and the call stops with Out of Energy and you still lose what it consumed. A common production value is high enough to cover the new-address case even when you expect energy to cover it. See out of energy.

What it costs at scale

Monthly transfers	Burned without energy	With energy at 3 TRX
1,000	~6,430 TRX	3,000 TRX
10,000	~64,300 TRX	30,000 TRX

These figures assume recipients hold USDT. Volume teams usually automate energy instead of burning TRX.

Cut fees automatically: rent energy via API

You have three approaches:

• Stake TRX and delegate it across your hot wallets. Good for very large stable volume. Check tron staking energy.
• Use a rental API to get energy before each payout.
• Mix them: stake for base volume and rent on peaks.

Our TRON Energy API is for businesses and is connected manually: write to @trx_meow_support on Telegram.