eth_signTransaction - Mantle RPC Method

Signs a transaction with the private key of the specified account on Mantle without submitting it to the network.

Why Mantle? Build on the world's largest ZK rollup by TVL with $2.5B+ secured and deep Bybit integration with near-instant ZK finality via OP Succinct, $6.2B treasury backing, mETH liquid staking, and 25% Bybit trading fee discounts.

Security Warning: Public Dwellir endpoints do not keep unlocked signers. On shared infrastructure, eth_signTransaction commonly returns a deprecation, unsupported-method, or account-management error instead of a signed payload. For production use, sign transactions client-side using libraries like ethers.js or web3.py, then broadcast with eth_sendRawTransaction.

When to Use This Method

eth_signTransaction is relevant for DeFi developers, liquid staking builders, and teams seeking institutional exchange integration in limited scenarios:

• Understanding the Signing Flow — Learn how transaction signing works before implementing client-side signing
• Local Development — Sign transactions on a local dev node (Hardhat, Anvil, Ganache) where accounts are unlocked
• Offline Signing Workflows — Generate signed transaction payloads for later broadcast

Code Examples

# Local dev node only. Public Dwellir endpoints do not expose unlocked-account signing.
curl -X POST http://127.0.0.1:8545 \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_signTransaction",
    "params": [{
      "from": "0x407d73d8a49eeb85d32cf465507dd71d507100c1",
      "to": "0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b",
      "gas": "0x76c0",
      "gasPrice": "0x9184e72a000",
      "value": "0x9184e72a",
      "nonce": "0x0"
    }],
    "id": 1
  }'

Common Use Cases

1. Offline Transaction Signing

Sign transactions on an air-gapped machine for later broadcast:

import { Wallet } from 'ethers';

async function createSignedTransaction(privateKey, to, value, { chainId, nonce, gasLimit }) {
  const wallet = new Wallet(privateKey);
  const tx = {
    to,
    value,
    gasLimit,
    nonce,
    chainId,
  };

  const signedTx = await wallet.signTransaction(tx);
  // Store signedTx and broadcast from an online machine
  return signedTx;
}

2. Batch Transaction Preparation

Pre-sign multiple transactions for sequential submission on Mantle:

async function prepareBatch(wallet, transactions) {
  const signed = [];

  for (let i = 0; i < transactions.length; i++) {
    const tx = {
      ...transactions[i],
      nonce: baseNonce + i
    };
    signed.push(await wallet.signTransaction(tx));
  }

  return signed; // Submit via eth_sendRawTransaction in order
}

Error Handling

Common errors and solutions:

Related Methods

• eth_sendRawTransaction — Broadcast a signed transaction
• eth_sendTransaction — Sign and send in one step (requires unlocked account)
• eth_accounts — List accounts available for signing