Get an API key

After login into your account on https://panel.holynode.com form the side menu create a new merchant.

At the end of steps of creating a new merchant it will gives you an API ket to call HolyNode Restful API endpoints.

You should pass the API key as x-api-key header for all requests.

    
   curl -X POST "https://api.holynode.com/fee/estimate" \
     -H "Content-Type: application/json" \
     -H "x-api-key: YOUR_API_KEY_HERE" \
     -d '{
          "fromAddress": "TSrcAddressExample123",
          "toAddress": "TDestAddressExample456",
          "contractAddress": "TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t",
          "amount": 1
        }'
                                                
                                                

To cover your smart contract transfer fee from address A to address B, you have multiple options.

1. Single API Call - Pay with Your Panel Balance (EASY)

In this method, you only need to increase your account balance in the HolyNode panel. Once funded, you can cover the fees for your transactions with a single API call. HolyNode will automatically deduct the required amount from your balance and fully cover the transaction fee, eliminating concerns about bandwidth, energy, or whether the address is activated on the Tron network.

You must call the Single API Call method right before sending your assets. The source address (address A) will receive the required fee instantly, and you can proceed with your transfer.

2. Double API Call - Pay with a Spender Address (EXPERT)

In this method, you don't need to pre-fund your HolyNode account. Instead, you can pay for each transaction individually and cover the fees using TRX.

First, call the HolyNode fee estimation endpoint to determine the required TRX amount for the transaction. Then, in the second API call, send your parameters along with a signed transaction from your spender address (which can be address A or any other address holding TRX) to cover the necessary transaction fees. You should not broadcast this signed transaction, HolyNode will handle broadcasting after validation.

This method is also secure, as there is no need to share private keys, manually broadcast transactions, or transfer TRX before validation.

The process involves calling the Fee Estimate API, signing a TRX transfer transaction with the spender address, and then calling the Fee Cover API with the feeCoverTransaction parameter.

📢Use the HolyNode address TC16R6y7UNDXUDf2DiQc36kTtBQXP21nFy on the Tron network as the recipient for the estimated fee in TRX.

Request:

• Send a request to [POST] https://api.holynode.com/fee/cover with following request body:
• Here we have and example to sending 1 USDT from an address to another address
  Copy

  {  
      "fromAddress": Required
          The source address holding 1 USDT to send
  
      "toAddress": Required
          The recipient address to receive 1 USDT
  
      "contractAddress": Required
          The contract address for the token you want to transfer. For example, for USDT, it is 'TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t' 
  
      "contractAmount": 1000000
          The amount to transfer based on token decimal precision
          For example, USDT has 6 decimals, so to send 1 USDT, you must pass 1000000
          If you do not know your contract decimal and how to change the amount to contract amount
          you can pass is like:
      OR    
      "amount": 1
          This is an alternative to 'contractAmount'. If provided, HolyNode will automatically convert it based 
          on the token's decimals. 
          For example, passing 1 for USDT set this parameter to 1
  
      "feeCoverTransaction": Optional
      If you have already increased your account balance on HolyNode and want to cover the fee with a single API call, 
      leave this field as null. Otherwise, send your signed transaction data from your spender address here.
      See more: 🔏 Sign Fee Cover Transaction
      
                                                                  
  }

  Example:
  Copy

  
      curl -X POST "https://api.holynode.com/fee/cover" \
      -H "Content-Type: application/json" \
      -H "x-api-key: YOUR_API_KEY_HERE" \
      -d '{
          "fromAddress": "TYHGuyBJH59ej1NCqhNpQf3UsaAn24FQPk" 
          "toAddress": "TFjh8dEYgDYY91DojVnEQT6dL1dLSJ3pXk"
          "contractAddress": "TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t"   
          "contractAmount": 1000000  
          }'
  

• Response:

• The response of the above request:
• Copy

Request:

• Send a request to [POST] https://api.holynode.com/fee/estimate with following request body:
• Here we have and example to sending 1 USDT from an address to another address
  Copy

  {  
      "fromAddress": 
          The source address holding 1 USDT to send
  
      "toAddress": 
          The recipient address to receive 1 USDT
  
      "contractAddress": 
          The contract address for the token you want to transfer. For example, for USDT, it is 'TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t' 
  
      "contractAmount": 1000000
          The amount to transfer based on token decimal precision
          For example, USDT has 6 decimals, so to send 1 USDT, you must pass 1000000
          If you do not know your contract decimal and how to change the amount to contract amount
          you can pass is like:
      OR    
      "amount": 1
          This is an alternative to 'contractAmount'. If provided, HolyNode will automatically convert it based 
          on the token's decimals. 
          For example, passing 1 for USDT set this paramter to 1
                                                                  
  }

  Example:
  Copy

  
      curl -X POST "https://api.holynode.com/fee/estimate" \
      -H "Content-Type: application/json" \
      -H "x-api-key: YOUR_API_KEY_HERE" \
      -d '{
          "fromAddress": "TYHGuyBJH59ej1NCqhNpQf3UsaAn24FQPk" 
          "toAddress": "TFjh8dEYgDYY91DojVnEQT6dL1dLSJ3pXk"
          "contractAddress": "TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t"   
          "contractAmount": 1000000  
          }'
  

Response:

• The response of the above request:
• Copy

• Here is a simple guide to create a singed transaction with your spender address.

  You must get the estimated TRX from the Fee Estimate API before proceeding. The Fee Estimate API should be called right before signing the fee cover transaction, and its information is valid for only a few minutes. You need to recall the endpoint to update the estimated TRX if needed.

• In Node.js:
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      const { TronWeb } = require('tronweb');
      const tronWeb = new TronWeb({
          fullHost: 'https://api.trongrid.io',
          headers: { 'TRON-PRO-API-KEY': 'TRON_GRID_API_KEY' },
      });
      async function getSignedTransaction(estimatedTrx, spenderPrivateKey) {
          const holyNodeAddress = 'TC16R6y7UNDXUDf2DiQc36kTtBQXP21nFy';
          const dataSendTrx = await tronWeb.transactionBuilder.sendTrx(holyNodeAddress, estimatedTrx, requestAddress);
          const signedTx = await tronWeb.trx.sign(dataSendTrx, spenderPrivateKey);
          return JSON.stringify(signedTx);
      }
  
  

• In Python:
• Copy

  
      from tronpy import Tron
      from tronpy.exceptions import TransactionError
  
      def get_signed_transaction(estimated_trx, spender_private_key):
          # Initialize Tron client
          client = Tron()
  
          # Set up the HolyNode address and the sender's address
          holy_node_address = 'TC16R6y7UNDXUDf2DiQc36kTtBQXP21nFy'
          spender_address = 'your_spender_address_here'  # Replace with actual spender address
  
          try:
              # Create transaction to send TRX
              txn = client.trx.transfer(spender_address, holy_node_address, estimated_trx)
  
              # Sign the transaction using the spender's private key
              signed_tx = txn.sign(spender_private_key)
  
              # Return the signed transaction
              return signed_tx
  
          except TransactionError as e:
              print(f"Error creating transaction: {e}")
              return None