Tron network transaction prices

Tron protobuf transaction structure. Transaction price in Tron network. Decode/encode tron transaction. Get free trx token in tron test network

To understand the price of transaction lets break down this article to multiple parts:

transaction structure and how to parse it
bandwidth and energy terms
resource consumptions
a simple example

Transaction structure

Tron transaction is encoded with protobuf and stored as binary in trongrid. When you call trongrid API you always pass this binary as a hex string (base16 0-9A-F). The protobuf structure is available at official tron github.com/tronprotocol/java-tron at protocol/src/main/protos/core /Tron.proto

There are 2 types of hex data you usually send

transaction data
transaction signature + transaction data

If you take a look at Tron.proto class you’ll find Transaction class that contains 2 fields.

raw_data (field number 1, type ‘raw’)
signature (field number 2, type ‘repeated bytes’)

If you have to parse such a hex transaction (with signature) you can do the following: With signature:

# pacman -S extra/protobuf
# git clone https://github.com/tronprotocol/java-tron
cd ./java-tron/protocol/src/main/protos/
echo 'long-hex-message-string-like-a30174b6c2223' | xxd -r -p - > message.bin
protoc --decode protocol.Transaction core/Tron.proto < message.bin

If you want to check the transaction without a signature you’ll spat that it’s a raw field Tron.proto file:

protoc --decode protocol.Transaction.raw core/Tron.proto < message.bin

You can also use https://protobuf-decoder.netlify.app/ but it won’t show you fields names and concrete types.

Tron transaction prices

So as we understand what transaction is, lets review how its price is formed.

There are 2 types of transactions:

native coin (trx), this uses tron bandwidth
smart contracts (e.g. USDT). this one uses both bandwidth and energy

If you don’t have enough energy/bandwidth, it will be burned automatically per current bandwidth/energy price. Current prices you can find out with:

The response will be in comma separated format with ‘price:timestamp’ value. e.g.

0:100,1575871200000:10,1606537680000:40,1614238080000:140,1635739080000:280,1681895880000:420

Which means that the latest energy price is 420 SUN (1000’000 SUN = 1 TRX).

Bandwidth consumption per transaction

Your transaction will consume exactly the amount of its length. So the less info you have in your transaction, the less bandwidth it burns. Since your transaction consist of 3 parts:

transaction data (the hex message, 2 hex chars = 1 byte) + 3 bytes of protobuf field
signature (65 bytes + 2 bytes of protobuf field start)
transaction output (up to 64 bytes)

So trx fee would be (BANDWIDTH_PRICE * TRANSACTION_LENGTH) SUN

if this is less than CURRENT_BANDWIDTH, it’s free
if more than the difference

Energy consumption per transaction

Let’s review USDT transfer. To estimate the energy required, you’ll need to check the code of the smart contract, particularly the function transfer you call (keccak256(transfer).substr(2,10) = “a9059cbb”). Since each smart contract is different, it’s much easier to use trongrid api to calc it. You can use estimateenergy api

curl --request POST \
     --url https://api.shasta.trongrid.io/wallet/estimateenergy \
     --header 'accept: application/json' \
     --header 'content-type: application/json' \
     --data '
{
  "owner_address": "TM94JwXLN33Gw4L8KF1eBPaEEPcdQi6hht",
  "contract_address": "TG3XXyExBkPp9nzdajDZsozEu4BkaSJozs",
  "function_selector": "transfer(address,uint256)",
  "parameter": "0000000000000000000000001c000dd56b9e634fe67346b89045990cb7bb821d00000000000000000000000000000000000000000000000000000000000f4240",
  "visible": true
}
'

Obtain test TRX and USDT tokens in Shasta trongrid.

If you install tronlink web extension, you can select TRON Shasta testnet on top of the screen. Then you can use a discord channel to obtain free tokens and even smart contract tokens like USDT. Just join discord group, go to faucet channel and type:

!shasta TM94JwXLN33Gw4L8KF1eBPaEEPcdQi6hht

To get TRX or

!shasta_usdt TM94JwXLN33Gw4L8KF1eBPaEEPcdQi6hht

To get USDT, where TM94JwXLN33Gw4L8KF1eBPaEEPcdQi6hht is your public address. You can post 1 message per 24 hours. But you are free to spam from multiple accounts to a single public address