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Send Transaction

Signs and broadcasts a transaction to the blockchain network, executing state-changing operations like transfers or contract method calls.

Common Properties​

  • Name - The custom name of the node.
  • Color - The custom color of the node.
  • Delay Before (sec) - Waits in seconds before executing the node.
  • Delay After (sec) - Waits in seconds after executing node.
  • Continue On Error - Automation will continue regardless of any error. The default value is false.
info

If the ContinueOnError property is true, no error is caught when the project is executed, even if a Catch node is used.

Inputs​

  • Client ID - The client ID from the Create Client node.
  • Transaction ID - The transaction ID from ABI Method or Transfer node.
  • Contract/To Address - The destination address (contract or wallet).
  • Gas Price - The gas price in hexadecimal format (from Estimate Gas Price).
  • Gas Limit - The maximum gas units the transaction can consume.
  • Value - The amount of native currency to send with the transaction in hex format (optional, use for payable functions).
  • Nonce - Transaction nonce for ordering (use 0 for automatic).

Output​

  • Hash - The transaction hash, a unique identifier for tracking the transaction on the blockchain.

How It Works​

The Send Transaction node executes a blockchain transaction. When executed, the node:

  1. Validates all inputs and retrieves the transaction data
  2. Gets the wallet's current nonce if not provided
  3. Constructs a transaction with all parameters
  4. Signs the transaction with the wallet's private key
  5. Broadcasts the signed transaction to the network
  6. Returns the transaction hash
  7. Cleans up temporary transaction data

Requirements​

  • Valid Client ID with sufficient balance for gas fees
  • Transaction ID from ABI Method or Transfer
  • Proper gas price and limit values
  • Network connectivity
  • Sufficient wallet balance (native currency + gas fees)

Error Handling​

The node will return errors for:

  • Invalid or missing Client ID
  • Transaction data not found
  • Invalid gas price or limit
  • Insufficient funds for gas
  • Nonce conflicts
  • Network failures
  • Transaction rejection by the network

Gas Parameters​

Gas Limit:

  • Simple ETH transfer: 21000
  • ERC20 transfer: 65000-100000
  • Complex contract calls: 100000-500000+
  • Use Estimate Gas to get accurate values

Gas Price:

  • Always use Estimate Gas Price for current prices
  • Format: Hexadecimal (e.g., 0x012a05f200 = 5 GWEI)
  • Higher prices = faster confirmation
  • Lower prices = cheaper but slower

Nonce Management​

Automatic (Recommended): Set Nonce to 0 for automatic nonce management.

Manual: Use when sending multiple transactions in sequence:

  1. Get current nonce from blockchain
  2. Increment for each transaction
  3. Send transactions with sequential nonces

Usage Notes​

  • This node sends actual transactions that cost gas
  • Transactions are irreversible once confirmed
  • Use Estimate Gas and Estimate Gas Price before sending
  • Wait for Transaction Receipt to confirm success
  • Store transaction hashes for tracking and audit
  • Multiple transactions from the same wallet need sequential nonces

Example​

Sending an ERC20 token transfer:

Inputs:

  • Client ID: 7e8f9a0b-1c2d-3e4f-5a6b-7c8d9e0f1a2b
  • Transaction ID: tx-123abc (from ABI Method with transfer function)
  • Contract/To Address: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 (USDC contract)
  • Gas Price: 0x012a05f200 (5 GWEI)
  • Gas Limit: 65000
  • Value: `` (empty for non-payable function)
  • Nonce: 0 (automatic)

Output:

  • Hash: 0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef

Sending ETH transfer:

Inputs:

  • Client ID: 7e8f9a0b-1c2d-3e4f-5a6b-7c8d9e0f1a2b
  • Transaction ID: (from Transfer node)
  • Contract/To Address: 0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb
  • Gas Price: 0x012a05f200
  • Gas Limit: 21000
  • Value: `` (amount specified in Transfer node)
  • Nonce: 0

Output:

  • Hash: 0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890

Common Use Cases​

Token Transfers: Send ERC20 tokens to users or contracts.

NFT Minting: Mint NFTs by calling contract mint functions.

DeFi Operations: Execute swaps, deposits, withdrawals on DeFi protocols.

Contract Deployment: Deploy new smart contracts to the blockchain.

State Updates: Update contract state variables or configurations.

Batch Operations: Execute multiple transactions in sequence.

danger

Always verify all transaction parameters before sending. Transactions cannot be reversed once confirmed. Double-check addresses, amounts, and gas settings.

tip

After sending a transaction, use the Transaction Receipt node to wait for confirmation and verify success. Don't assume a transaction succeeded just because it was broadcast.

Transaction Flow​

  1. Prepare - Use ABI Method or Transfer
  2. Estimate - Get gas price and limit
  3. Validate - Check balance and parameters
  4. Send - Execute with Send Transaction
  5. Track - Store transaction hash
  6. Confirm - Check Transaction Receipt
  7. Handle - Process success or failure

Gas Cost Calculation​

Total cost = Gas Price × Gas Limit

Example:

  • Gas Price: 20 GWEI
  • Gas Limit: 65,000
  • Cost: 20 × 65,000 = 1,300,000 GWEI = 0.0013 ETH

Transaction States​

After sending:

  1. Pending - Broadcast but not mined
  2. Confirmed - Included in a block
  3. Failed - Reverted or out of gas
  4. Dropped - Replaced or timed out

Use Transaction Receipt to check final state.

warning

Set appropriate gas limits. Too low causes failure, too high wastes money. Use Estimate Gas for accurate values.