v0 — Buy with Private Key

Full working example for buying Energy via the TronSave v0 API by signing a TRX transaction with your own private key.

Legacy example. This page uses the v0 TronSave API and TronWeb 5.3.2. It is kept for reference and backwards compatibility. For new integrations, use the current Signed Transaction flow in Buy Resources and the Developer Quickstart.

This example shows the complete Signed Transaction flow: estimate the cost, sign a TRX transfer to the TronSave receiver address with your private key, and create the buy order — all without depositing TRX into an internal account.

Requirement

TronWeb version 5.3.2

npm i tronweb@5.3.2 @noble/secp256k1@1.7.1

Configuration

The example reads four endpoint/address constants. The values differ between mainnet and the Nile testnet:

Constant

Mainnet

Testnet (Nile)

TRONSAVE_RECEIVER_ADDRESS

TWZEhq5JuUVvGtutNgnRBATbF8BnHGyn4S

TATT1UzHRikft98bRFqApFTsaSw73ycfoS

TRON_FULLNODE

https://api.trongrid.io

https://api.nileex.io

TRONSAVE_API_URL

https://api.tronsave.io

https://api-dev.tronsave.io

Set PRIVATE_KEY, REQUEST_ADDRESS, and TARGET_ADDRESS before running. BUY_AMOUNT and DURATION can be changed to fit your order.

Full example

const TronWeb = require('tronweb')

const TRONSAVE_RECEIVER_ADDRESS = "TWZEhq5JuUVvGtutNgnRBATbF8BnHGyn4S" //in testnet mode change it to "TATT1UzHRikft98bRFqApFTsaSw73ycfoS"
const PRIVATE_KEY = "your_private_key" //Change it
const TRON_FULLNODE = "https://api.trongrid.io"  //in testnet mode change it to "https://api.nileex.io"
const TRONSAVE_API_URL = "https://api.tronsave.io" //in testnet mode change it to "https://api-dev.tronsave.io"

const REQUEST_ADDRESS = "your_request_address" //Change it
const TARGET_ADDRESS = "your_target_address" //Change it
const BUY_AMOUNT = 100000 //Chanageable
const DURATION = 3 * 86400 * 1000 //3 days.Changeable

const tronWeb = new TronWeb({
    fullNode: TRON_FULLNODE,
    solidityNode: TRON_FULLNODE,
    eventServer: TRON_FULLNODE,
    privateKey: PRIVATE_KEY,
})

const GetEstimate = async (request_address, target_address, amount, duration) => {
    const url = TRONSAVE_API_URL + "/v0/estimate-trx"
    //see more at https://docs.tronsave.io/buy-energy-on-telegram/using-api-key-to/buy-energy
    const body = {
        "amount": amount,
        "buy_energy_type": "MEDIUM",
        "duration_millisec": duration,
        "request_address": request_address,
        "target_address": target_address || request_address,
        "is_partial": true
    }
    const data = await fetch(url, {
        method: "POST",
        headers: {
            "content-type": "application/json",
        },
        body: JSON.stringify(body)
    })
    const response = await data.json()
    /**
     * Example response 
     * @link  https://docs.tronsave.io/market/how-to-buy-energy/buy-on-rest-api
   {
        "unit_price": 45,
        "duration_millisec": 259200000,
        "available_energy": 4298470,
        "estimate_trx": 13500000,
    }
     */
    return response
}

const GetSignedTransaction = async (estimate_trx, request_address) => {
    const dataSendTrx = await tronWeb.transactionBuilder.sendTrx(TRONSAVE_RECEIVER_ADDRESS, estimate_trx, request_address)
    const signed_tx = await tronWeb.trx.sign(dataSendTrx, PRIVATE_KEY);
    return signed_tx
}

const CreateOrder = async (signed_tx, target_address, unit_price, duration) => {
    const url = TRONSAVE_API_URL + "/v0/buy-energy"
    //see more at https://docs.tronsave.io/buy-energy-on-telegram/using-api-key-to/buy-energy
    const body = {
        "resource_type": "ENERGY",
        "unit_price": unit_price,
        "allow_partial_fill": true,
        "target_address": target_address,
        "duration_millisec": duration,
        "tx_id": signed_tx.txID,
        "signed_tx": signed_tx
    }
    const data = await fetch(url, {
        method: "POST",
        headers: {
            "content-type": "application/json",
        },
        body: JSON.stringify(body)
    })
    const response = await data.text()
    //Example response 
    // @link  https://docs.tronsave.io/market/how-to-buy-energy/buy-on-rest-api
    // "651d2306e55c073f6ca0992e" //order id in tronsave
    return response
}

const BuyEnergyUsingPrivateKey = async () => {
    //Step 1: Estimate the cost of buy order
    const estimate_data = await GetEstimate(REQUEST_ADDRESS, TARGET_ADDRESS, BUY_AMOUNT, DURATION)
    const { unit_price, estimate_trx, available_energy } = estimate_data
    console.log(estimate_data)
    /*
    {
        "unit_price": 45,
        "duration_millisec": 259200000,
        "available_energy": 4298470,
        "estimate_trx": 13500000,
    }
     */
    const is_ready_fulfilled = available_energy >= BUY_AMOUNT //if available_energy equal buy_amount it means that your order can be fulfilled 100%
    if (is_ready_fulfilled) {
        //Step 2: Build signed transaction by using private key
        const signed_tx = await GetSignedTransaction(estimate_trx, REQUEST_ADDRESS)
        console.log(signed_tx);
        /*
        {
            "resource_type": "ENERGY",
            "unit_price": 45,
            "allow_partial_fill": true,
            "target_address": "TM6ZeEgpefyGWeMLuzSbfqTGkPv8Z6Jm4X",
            "duration_millisec": 259200000,
            "tx_id": "446eed36e31249b98b201db2e81a3825b185f1a3d8b2fea348b24fc021e58e0d",
            "signed_tx": {
            "visible": false,
            "txID": "446eed36e31249b98b201db2e81a3825b185f1a3d8b2fea348b24fc021e58e0d",
            "raw_data": {
                "contract": [
                {
                    "parameter": {
                    "value": {
                        "amount": 13500000,
                        "owner_address": "417a0d868d1418c9038584af1252f85d486502eec0",
                        "to_address": "41055756f33f419278d9ea059bd2b21120e6add748"
                    },
                    "type_url": "type.googleapis.com/protocol.TransferContract"
                    },
                    "type": "TransferContract"
                }
                ],
                "ref_block_bytes": "0713",
                "ref_block_hash": "6c5f7686f4176139",
                "expiration": 1691465106000,
                "timestamp": 1691465046758
            },
            "raw_data_hex": "0a02071322086c5f7686f417613940d084b5999d315a68080112640a2d747970652e676f6f676c65617069732e636f6d2f70726f746f636f6c2e5472616e73666572436f6e747261637412330a15417a0d868d1418c9038584af1252f85d486502eec0121541055756f33f419278d9ea059bd2b21120e6add74818e0fcb70670e6b5b1999d31",
            "signature": ["xxxxxxxxx"]
            }
        }
         */
        //Step 3: Create order
        const dataCreateOrder = await CreateOrder(signed_tx, TARGET_ADDRESS, unit_price, DURATION)
        console.log(dataCreateOrder);
    }
}

BuyEnergyUsingPrivateKey()

How it works

Estimate — POST /v0/estimate-trx returns the unit_price, available_energy, and estimate_trx (the TRX cost, in SUN) for your requested BUY_AMOUNT and DURATION.
Sign — Build a TRX transfer of estimate_trx to TRONSAVE_RECEIVER_ADDRESS and sign it locally with your private key. No TRX is moved until the order is created.
Create order — POST /v0/buy-energy submits the signed transaction. On success the response is the order ID, e.g. "651d2306e55c073f6ca0992e".

The example only proceeds to sign and create the order when available_energy >= BUY_AMOUNT, ensuring the order can be filled 100%.

Never commit your PRIVATE_KEY to source control or share it. Load it from a secure environment variable or secret manager in production.

Next steps

Migrate to the current API: Buy Resources
Compare auth methods: Authentication
Learn the rental model: Concepts → Rental Model

Previousv2 — Extend with API Key

Nextv0 — Buy with API Key

Last updated 4 months ago