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RPC method

eth_sendRawTransaction on Monad

Supported on SwiftNodes

Everything below was measured on 2026-10-13 by calling eth_sendRawTransaction on Monad through the same endpoint customers use, and is re-measured weekly.

What eth_sendRawTransaction does

Submits a signed transaction to the network and returns its hash. The node checks the signature, chain ID, nonce and balance first, and returns an error string instead of a hash when any check fails, which is the text your app has to handle.

Errors Monad returns, word for word

We submitted three transactions that must fail, signed by a new, empty key (nothing was spent). These are the messages your app receives in those situations.

EIP-1559 transfer from an empty accountSigner had insufficient balance
Legacy transaction signed without a chain ID (pre-EIP-155)Signer had insufficient balance
Truncated bytes ("0x02f8")Transaction decoding error

How to read them

Monad's nodes refuse transactions without a chain ID ("Signer had insufficient balance"), so old signing code that omits it fails here.

Send the same signed bytes again only if you never got a hash back: a second submission of an accepted transaction returns an "already known" style error, not a second transaction, and a transaction with the same nonce but a higher fee replaces it.

Example request

curl -s https://rpc.swiftnodes.io/rpc/monad?key=YOUR_API_KEY \
  -X POST -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_sendRawTransaction","params":["0x02f8..."]}'
import { createPublicClient, http } from "viem";

const client = createPublicClient({
  transport: http("https://rpc.swiftnodes.io/rpc/monad?key=YOUR_API_KEY"),
});

try {
  const hash = await client.sendRawTransaction({ serializedTransaction: signed });
  const receipt = await client.waitForTransactionReceipt({ hash });
} catch (e) {
  const msg = String(e?.details ?? e?.message);
  if (/insufficient funds/i.test(msg)) { /* ask the user to top up */ }
  else if (/nonce too low|already known/i.test(msg)) { /* already sent: look up by hash */ }
  else throw e;
}

Other methods on Monad

eth_sendRawTransaction on other chains

Frequently asked questions

Does Monad support eth_sendRawTransaction?

Yes. eth_sendRawTransaction answered on the SwiftNodes Monad endpoint when our weekly probe called it through the customer path (2026-10-13).

Does Monad accept transactions without a chain ID?

No. It answered "Signer had insufficient balance".

Monad endpoints, live block height and WebSocket status are on the Monad RPC page.

One key covers every chain we serve, and SwiftNodes has a free tier.