eth_sendRawTransactionSync

Submits a signed transaction and waits synchronously for inclusion in a Flashblock before returning. Unlike eth_sendRawTransaction which returns immediately with just the transaction hash, this method blocks until the transaction is included in a Flashblock and returns a full transaction receipt.

This enables sub-200ms transaction confirmation flows — the response includes the receipt with blockNumber, gasUsed, logs, status, and L2-specific fields like l1Fee.

Use Cases

• Instant confirmation UX — Display transaction results immediately without polling
• Synchronous workflows — Chain dependent operations without receipt polling
• Payment processing — Confirm payment transactions inline
• Bot and MEV operations — Confirm execution before proceeding

Parameters

Parameter	Type	Required	Description
signedTransactionData	DATA	Yes	The signed transaction data (RLP encoded)

Request

{
  "jsonrpc": "2.0",
  "method": "eth_sendRawTransactionSync",
  "params": ["0xf86c..."],
  "id": 1
}

Returns

Returns a full transaction receipt (same format as eth_getTransactionReceipt):

Field	Type	Description
transactionHash	DATA	32-byte transaction hash
blockHash	DATA	32-byte block hash (may be zero for preconfirmed blocks)
blockNumber	QUANTITY	Block number the transaction was included in
gasUsed	QUANTITY	Gas consumed by the transaction
status	QUANTITY	0x1 for success, 0x0 for revert
logs	Array	Logs emitted by the transaction
l1Fee	QUANTITY	L1 data posting fee charged
l1GasUsed	QUANTITY	Gas used for L1 data posting

Code Examples

cURL

curl -X POST https://api-base-mainnet-archive.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_sendRawTransactionSync",
    "params": ["0xf86c808504a817c80082520894..."],
    "id": 1
  }'

JavaScript

import { Wallet, parseEther, JsonRpcProvider } from 'ethers';

const provider = new JsonRpcProvider(
  'https://api-base-mainnet-archive.n.dwellir.com/YOUR_API_KEY'
);
const wallet = new Wallet('YOUR_PRIVATE_KEY', provider);

// Build and sign the transaction
const tx = await wallet.populateTransaction({
  to: '0x...',
  value: parseEther('0.01'),
});
const signedTx = await wallet.signTransaction(tx);

// Send synchronously — returns full receipt, not just hash
const receipt = await provider.send('eth_sendRawTransactionSync', [signedTx]);

console.log('Status:', receipt.status === '0x1' ? 'success' : 'reverted');
console.log('Block:', parseInt(receipt.blockNumber, 16));
console.log('Gas used:', parseInt(receipt.gasUsed, 16));
console.log('L1 fee:', parseInt(receipt.l1Fee, 16));

Python

from web3 import Web3

w3 = Web3(Web3.HTTPProvider('https://api-base-mainnet-archive.n.dwellir.com/YOUR_API_KEY'))

account = w3.eth.account.from_key('YOUR_PRIVATE_KEY')
tx = {
    'nonce': w3.eth.get_transaction_count(account.address),
    'to': '0x...',
    'value': w3.to_wei(0.01, 'ether'),
    'gas': 21000,
    'maxFeePerGas': w3.eth.gas_price,
    'maxPriorityFeePerGas': w3.eth.max_priority_fee,
    'chainId': 8453
}

signed_tx = account.sign_transaction(tx)

# Send synchronously — returns full receipt
receipt = w3.provider.make_request(
    'eth_sendRawTransactionSync',
    [signed_tx.raw_transaction.hex()]
)

print(f"Status: {receipt['result']['status']}")
print(f"Block: {int(receipt['result']['blockNumber'], 16)}")

Response Example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "transactionHash": "0x...",
    "blockHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "blockNumber": "0x29442e3",
    "gasUsed": "0x5208",
    "status": "0x1",
    "logs": [],
    "l1Fee": "0xa5fce0e0",
    "l1GasUsed": "0x34dc"
  }
}

note

The blockHash may be 0x000...000 because the transaction was included in a Flashblock that hasn't been sealed into a final block yet. The receipt is a preconfirmation — the transaction will be included in the next sealed block.

Error Handling

Error Code	Message	Description
-32602	Failed to decode signed transaction	Invalid RLP-encoded transaction data
-32000	Nonce too low	Transaction nonce already used
-32000	Insufficient funds	Account has insufficient balance

Related Methods

• eth_sendRawTransaction — Async version (returns hash immediately)
• eth_getTransactionReceipt — Get receipt for a previously sent transaction
• eth_simulateV1 — Simulate transactions before sending

---

Need help? Contact our support team or check the Base documentation.